Golf Club Head

Abstract

To provide a golf club head of a new structure having an enhanced rebound performance.SOLUTION: A head 4 includes a body member b1 that has an opening b10, and a face member f1 that includes a striking face 10a and closes the opening b10. The face member f1 includes a face portion 10 that forms the striking face 10a, and a peripheral portion 32 that extends from a peripheral edge of the face portion 10 toward a back side. At the peripheral portion 32, the face member f1 is welded to the body member b1. A weld bead wb, which juts from the inner surface of the head 4, is formed at a boundary position between the peripheral portion 32 and the body member b1. A wall thickness t11 at a face-side end point of the weld bead wb is greater than a wall thickness t21 at a body-side end point of the weld bead wb. The peripheral portion 32 has a length L1 of less than or equal to 6 mm.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to golf club heads. [Background technology]

[0002] A golf club head in which a face member and a head body are welded is known. Also, a golf club head in which a face member has a cup face structure is known. JP 2020-191938 A discloses a golf club head in which a face member having a peripheral portion and a head body are joined by welding. In this head, the peripheral portion has a thick portion joined to an end face of an opening of the head body, and a connecting portion connecting the thick portion and the face portion. The connecting portion has a thin portion that is thinner than the thick portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-191938 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a head with higher repulsion performance. The present inventor has discovered a new structure capable of improving repulsion performance in a head in which a face member and a body member are joined. It has been found that repulsion performance can be improved by increasing the rigidity of the portion that is easily bent in the conventional structure and shifting the position of bending. One of the purposes of the present disclosure is to provide a golf club head capable of improving repulsion performance with a new structure. [Means for solving the problem]

[0005] In one embodiment, the golf club head has an outer surface and an inner surface, and is hollow. The head includes a body member having an opening, and a face member having a striking face and closing the opening. The face member has a face portion constituting the striking face, and a peripheral portion extending from the outer edge of the face portion toward the back side. The peripheral portion of the face member is welded to the body member. A weld bead is formed on the inner surface of the head at the boundary between the peripheral portion and the body member. The thickness of the weld bead at the end point on the face side is greater than the thickness of the weld bead at the end point on the body side. The length of the peripheral portion is 6 mm or less. Effect of the Invention

[0006] In one aspect, a golf club head is provided that can improve repulsion performance through a new structure. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 shows a golf club equipped with a head according to a first embodiment. [Diagram 2] Fig. 2(a) is a front view of the head of the first embodiment as seen from the face side, and Fig. 2(b) is a cross section taken along line E1 in Fig. 2(a). In Fig. 2(b), only the cross section line of the outer surface of the head is shown. [Diagram 3] FIG. 3 is a plan view of the head of the first embodiment as viewed from the crown side. [Figure 4] FIG. 4 is a bottom view of the head of the first embodiment as viewed from the sole side. [Diagram 5] FIG. 5 is a cross-sectional view taken along the line AA in FIG. [Figure 6] FIG. 6 is an exploded perspective view of the head of the first embodiment. [Figure 7] FIG. 7 is an enlarged view of the face portion and its vicinity in FIG. [Figure 8] FIG. 8 is an enlarged view of the inside of circle A in FIG. [Figure 9] FIG. 9 is an enlarged view of the area within circle B in FIG. [Figure 10] FIG. 10 is a conceptual diagram for explaining the reference state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the present disclosure will be described in detail based on preferred embodiments with appropriate reference to the drawings.

[0009] In the present application, a reference state, a reference vertical plane, a toe-heel direction, a face-back direction, an up-down direction, a face center, a vertical section, and a radius of curvature are defined.

[0010] A state in which the head is placed on the ground plane HP at a predetermined lie angle is regarded as a reference state. As shown in Fig. 10, 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 shaft axis line Z is the center line of the hosel hole. The plane VP is regarded as a reference vertical plane. The predetermined lie angle is listed in, for example, a product catalog.

[0011] In this reference state, the face angle is set to 0 degrees. That is, in a plan view seen from above, a tangent to the face center of the hitting face is set to be parallel to the toe-heel direction. The face center and the toe-heel direction are defined as described below.

[0012] In this application, 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. 10). The toe side in the toe-heel direction is also simply referred to as the "toe side". The heel side in the toe-heel direction is also simply referred to as the "heel side".

[0013] In the present application, the face-back direction is a direction perpendicular to the toe-heel direction and parallel to the ground plane HP. The face side in the face-back direction is also simply referred to as the "face side". The back side in the face-back direction is also simply referred to as the "back side".

[0014] In the present application, the vertical direction is a direction perpendicular to the toe-heel direction and perpendicular to the face-back direction. In other words, in the present application, the vertical direction is a direction perpendicular to the ground plane HP.

[0015] In the present application, the face center is determined as follows. First, an arbitrary point Pr is selected that is approximately near the center of the hitting face in the up-down direction and the toe-heel direction. Next, a plane is determined that passes through this point Pr, extends along the normal direction of the hitting face at the point Pr, and is parallel to the toe-heel direction. A line of intersection between this plane and the hitting face is drawn, and its midpoint Pa is determined. Next, a plane is determined that passes through this midpoint Pa, extends along the normal direction of the hitting face at the point Pa, and is parallel to the up-down direction. A line of intersection between this plane and the hitting face is drawn, and its midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal direction of the hitting face at the point Py, and is parallel to the toe-heel direction. A line of intersection between this plane and the hitting face 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 direction of the hitting face at the point Px, and is parallel to the up-down direction. A line of intersection between this plane and the striking face is drawn, and its midpoint Py is determined. This process is repeated to determine Px and Py in sequence. In the repetition of this process, the new position Py (last position Py) when the distance between the new midpoint Py and the previous midpoint Py is 0.5 mm or less for the first time is the face center.

[0016] In the present application, the longitudinal section is a section along a plane perpendicular to the toe-heel direction. The longitudinal section is parallel to the face-back direction. The longitudinal section is perpendicular to the ground plane HP. A section line in the longitudinal section is also called a longitudinal section line. The longitudinal section can be set at each position in the toe-heel direction.

[0017] The radius of curvature of the curved surface is measured at the longitudinal planes. That is, the radius of curvature of the curved surface is measured at the longitudinal plane lines. The longitudinal planes exist at each position in the toe-heel direction. At each of these longitudinal planes, the radius of curvature is measured.

[0018] This radius of curvature is determined at each point on the longitudinal section line. In determining this radius of curvature, three points are identified: the measurement point and two points 0.5 mm apart on either side of the measurement point. The radius of the circle that passes through these three points is defined as the radius of curvature of the measurement point. This 0.5 mm is the path distance along the section line. 0.5 mm is small enough to evaluate the radius of curvature of the measurement point. Also, by setting two points 0.5 mm apart from the measurement point, the radius of curvature at each point on the free curve can be determined without solving the differential equation of the section line.

[0019] In this manner, the radius of curvature is determined for each point. In this application, the definition that the radius of curvature in a certain region is from X mm to Y mm means that the radius of curvature is from X mm to Y mm at all points belonging to that region.

[0020] In the present application, in the longitudinal section, points on the inner surface of the head correspond to points on the outer surface of the head. Point A on the outer surface of the head has a normal line. When the intersection point of this normal line and the inner surface of the head is point B, point A and point B correspond to each other. In this case, it may be said that point A corresponds to point B, and point B corresponds to point A.

[0021] FIG. 1 is an overall view of a golf club 2 including a head 4 according to an embodiment of the present disclosure. FIG. 2(a) is a front view of the head 4, and FIG. 2(b) is a cross-section taken along line E1 in FIG. 2(a). In FIG. 2(b), only the cross-section line of the outer surface of the head 4 is shown. FIG. 3 is a plan view of the head 4 seen from the crown side. FIG. 4 is a bottom view of the head 4 seen from the sole side. FIG. 5 is a cross-section taken along line AA in FIG. 2(a). FIG. 5 is a vertical cross-section passing through the face center Fc. FIG. 6 is an exploded perspective view of the head 4.

[0022] 1, the golf club 2 includes a golf club head 4, a shaft 6, and a grip 8. The shaft 6 has a tip end Tp and a butt end Bt. The head 4 is attached to the tip end of the shaft 6. The grip 8 is attached to the butt end of the shaft 6.

[0023] The golf club 2 is a driver (No. 1 wood). Preferably, the golf club 2 is a wood type golf club or a hybrid type golf club.

[0024] The shaft 6 is a tubular body. The shaft 6 has a hollow structure. The material of the shaft 6 is carbon fiber reinforced resin. From the viewpoint of weight reduction, the material of the shaft 6 is preferably carbon fiber reinforced resin. The shaft 6 is a so-called carbon shaft. Preferably, the shaft 6 is formed by curing a prepreg sheet. In this prepreg sheet, the fibers are substantially oriented in one direction. A prepreg in which the fibers are substantially oriented in one direction in this manner is also called a UD prepreg. "UD" is an abbreviation for unidirectional. A prepreg other than a UD prepreg may be used. For example, the fibers contained in the prepreg sheet may be woven. The shaft 6 may include a metal wire. The material of the shaft 6 is not limited, and may be, for example, a metal.

[0025] The grip 8 is a portion that is held by a golfer during a swing. A rubber composition and a resin composition are exemplified as materials for the grip 8. The rubber composition of the grip 8 may contain air bubbles.

[0026] As shown in FIG. 5, the head 4 has a hollow structure. In this embodiment, the head 4 is a wood type. The head 4 may be a hybrid type. The head 4 may be an iron type. The head 4 may be a putter type. Preferably, the head 4 is a wood type or a hybrid type, more preferably a wood type. Preferable materials for the head 4 include metal and fiber reinforced plastic. Examples of the metal include titanium alloy, pure titanium, stainless steel, maraging steel, and soft iron. Examples of the fiber reinforced plastic include carbon fiber reinforced plastic. The head 4 may be a composite head having a metal portion and a fiber reinforced plastic portion.

[0027] As shown in Fig. 2(a) to Fig. 4, the head 4 has a face portion 10, a crown portion 12, a sole portion 14, and a hosel portion 16. The face portion 10 has a hitting face 10a. The hitting face 10a is the outer surface of the face portion 10. The hitting face 10a is also simply referred to as a face. The hitting face 10a has a face center Fc. The definition of the face center Fc is as described above. The hosel portion 16 has a shaft hole 16a.

[0028] The outer edge of the hitting face 10a can be defined as follows. As shown in FIG. 2(a) and FIG. 2(b), there are cross sections E1, E2, E3, etc., including a straight line N1 connecting the center of gravity CG of the head 4 and the sweet spot SS. In the front view of FIG. 2(a), the straight line N1 is a point. In each of these cross sections E1, etc., a position Fe is determined where the radius of curvature r of the cross section line of the outer surface of the head becomes 200 mm for the first time from the sweet spot SS side toward the outside of the hitting face 10a. This position Fe is defined as the outer edge of the hitting face 10a. The sweet spot SS is the foot of a perpendicular line drawn from the center of gravity CG of the head 4 to the hitting face 10a.

[0029] As shown in Fig. 5, the face portion 10 has a face outer surface 10a and a face inner surface 10b. The face outer surface 10a is a hitting face. The face inner surface 10b faces the internal space (hollow portion) of the head 4. The crown portion 12 has a crown outer surface 12a and a crown inner surface 12b. The crown inner surface 12b faces the internal space (hollow portion) of the head 4. The sole portion 14 has a sole outer surface 14a and a sole inner surface 14b. The sole inner surface 14b faces the internal space (hollow portion) of the head 4.

[0030] Although scorelines (grooves) are provided on the face outer surface 10a, illustration of these scorelines is omitted in the drawings of the present application.

[0031] The hollow head 4 has a thickness. The thickness is the thickness between the inner surface of the head 4 and the outer surface of the head 4. For example, the thickness of the face portion 10 is the thickness between the striking face 10a and the face inner surface 10b. For example, the thickness of the sole portion 14 is the thickness between the sole outer surface 14a and the sole inner surface 14b. The thickness is measured along a normal to the outer surface of the head. The direction of this normal varies depending on the position on the outer surface of the head.

[0032] As clearly shown in FIG. 3, the crown portion 12 has a crown protrusion 20 on the crown outer surface 12a. The crown protrusion 20 is hollow. That is, the crown protrusion 20 forms a convex shape on the crown outer surface 12a and a concave shape on the crown inner surface. The crown protrusion 20 has a contour line CL20, an upper surface 22, and a side wall surface 24. In a plan view of the head 4 (FIG. 3), the crown protrusion 20 is substantially quadrangular (substantially trapezoidal). The crown protrusion 20 is provided on the heel side of the face center Fc.

[0033] The face outer surface 10a is a three-dimensional curved surface that is convex toward the outside of the head 4. The face outer surface 10a has a bulge and a roll.

[0034] In terms of components, the head 4 has a body member b1 and a face member f1. The body member b1 has a face opening b10. The face member f1 is disposed in the face opening b10. The face member f1 has the entire striking face 10a. The face member f1 closes the face opening b10. The face member f1 is welded to the face opening b10. The face member f1 has a portion of the crown portion 12. The face member f1 has a portion of the sole portion 14. The body member b1 has a portion of the crown portion 12. The body member b1 has a portion of the sole portion 14. The body member b1 has the entire hosel portion 16.

[0035] In Figs. 3 and 4, the two-dot chain line indicates a boundary line k1 between the face member f1 and the body member b1 on the outer surface of the head.

[0036] The material of the body member b1 is not limited, and examples thereof include metal and fiber-reinforced plastic. Examples of the metal include one or more metals selected from pure titanium, titanium alloy, stainless steel, maraging steel, aluminum alloy, magnesium alloy, and tungsten-nickel alloy. Examples of the fiber-reinforced plastic include carbon fiber-reinforced plastic. The body member b1 may be integrally molded as a whole. The body member b1 may be formed by joining a plurality of members. For example, the body member b1 may be formed by joining a metal member and a carbon fiber-reinforced plastic member. In this embodiment, the body member b1 is entirely made of metal. The manufacturing method of the body member b1 is not limited. In this embodiment, the body member b1 is manufactured by casting (lost wax precision casting).

[0037] The material of the face member f1 is not limited, and metal is preferable. However, at least the peripheral portion 32 (described later) is formed of a material that can be welded to the opening b10 of the body member b1. From the viewpoint of strength, titanium alloy and maraging steel are preferable materials for the face member f1. The manufacturing method of the face member f1 is not limited. From the viewpoint of strength, the face member f1 may be manufactured by pressing a plate material. A rolled material may be used as the plate material. The rolled material has few defects and is excellent in strength. Furthermore, the rolled material has high thickness accuracy. By using the rolled material, the thickness accuracy of the face portion 10 is increased. The face member f1 may be manufactured by, for example, forging. The face member f1 may be manufactured by casting. As described later, the face member f1 of this embodiment has a small peripheral portion. Therefore, the face member f1 can be easily formed by pressing or forging. In this embodiment, the face member f1 is manufactured by pressing a rolled material. More specifically, the manufacturing process of the face member f1 may include a first step of processing a plate material (rolled material) to a thickness by CNC processing, a second step of pressing the plate material after the first step, and a third step of shaping the peripheral portion by CNC processing using the material after the second step. In the second step, a curved surface (bulge, roll) of the face portion is given and a curved peripheral portion is formed. However, when the peripheral portion is short, such as the peripheral portion 32 of the face member f1, bending is difficult and the peripheral portion may not be completely shaped by pressing alone. In this case, it is preferable to carry out the third step of shaping the peripheral portion after the pressing step. The shaping in this third step includes shaping the length of the peripheral portion and / or shaping the outer surface shape of the peripheral portion. Laser cutting may be used to shaping the length of the peripheral portion. CNC processing may be used to shaping the outer surface shape of the peripheral portion. When the outer surface shape of the peripheral portion is adjusted in the third process, the thickness can be set in the first process, taking into consideration the amount of cutting of the outer surface in the third process. Note that CNC is an abbreviation for Computerized Numerical Control.

[0038] FIG. 7 is an enlarged view of the vicinity of the face portion 10 in FIG. 5. FIG. 8 is an enlarged view of the inside of circle A in FIG. 5. As described above, the head 4 has a face member f1. The face member f1 is integrally molded as a whole. The face member f1 is welded to the body member b1. What is shown by a dashed line in FIG. 7 and FIG. 8 is the boundary surface k2 between the face member f1 and the body member b1. The boundary surface k2 is the interface between the rear end surface of the face member f1 and the front end surface of the body member b1. In the longitudinal section, the boundary surface k2 forms a cross-sectional boundary line k3.

[0039] 9 is an enlarged view of circle B in FIG. 8. The cross-sectional boundary line k3 has point P1 on the inner surface of the head and point P2 located on the outer surface of the head. Point P1 is covered by the weld bead wb. The cross-sectional boundary line k3 is a line segment connecting point P1 and point P2. The aforementioned boundary line k1 is a set of points P2.

[0040] The face member f1 has a face portion 10 constituting a hitting face 10a, and a peripheral portion 32 extending from the periphery of the face portion 10 toward the back side. As shown in FIG. 6, the peripheral portion 32 is provided over the entire circumference of the face member f1, except for the vicinity of the hosel portion 16. However, as shown in FIGS. 6 and 7, the length of the peripheral portion 32 is short. The peripheral portion 32 includes a sole-side peripheral portion 34 and a crown-side peripheral portion 36. The sole-side peripheral portion 34 extends from the lower edge of the face portion 10 toward the back side. The crown-side peripheral portion 36 extends from the upper edge of the face portion 10 toward the back side. The rear end surface of the face member f1 is the rear end surface of the peripheral portion 32.

[0041] A weld bead wb is formed at the welded portion. The weld bead wb is formed at the boundary between the peripheral edge portion 32 and the body member b1. The weld bead wb is formed on the inner surface of the head 4. The weld bead wb protrudes from the inner surface of the head. In the cross-sectional views of the present application, the weld bead wb is shown diagrammatically as a semicircle.

[0042] The type of welding is not limited, and examples include laser welding, arc welding, gas welding, and resistance welding. A filler material (such as a welding rod) may or may not be used. In this embodiment, laser welding is adopted. The weld bead wb may be formed only from the base material, may be formed only from the filler material, or may be formed from the base material and the filler material. In this embodiment, no filler material is used, and the weld bead wb is formed from the melted and solidified base material (body member b1 and face member f1).

[0043] As shown in FIG. 7, in the longitudinal section, the cross-sectional line of the striking face 10a has a midpoint Pa. The midpoint Pa is the midpoint of the cross-sectional line extending between the sole-side outer edge Fe and the crown-side outer edge Fe. The midpoint Pa is determined for each longitudinal section. The midpoint Pa has a tangent Ta. The tangent Ta is a tangent to the cross-sectional line of the striking face 10a at the midpoint Pa. The face inner surface 10b has a point Pb. The point Pb is a point corresponding to the point Pa. In other words, the point Pb is the intersection of the normal line D1 at the midpoint Pa and the face inner surface 10b. A straight line Tb that passes through the point Pb and is parallel to the tangent Ta is determined.

[0044] The peripheral portion 32 has a rear extension portion 38 that protrudes further back than the face portion 10. The rear extension portion 38 is a portion that extends further back than the straight line Tb. The rear extension portion 38 includes a sole-side rear extension portion 40 and a crown-side rear extension portion 42.

[0045] As shown in Figs. 7 and 9, the peripheral portion 32 has a length L1. The length L1 of the peripheral portion 32 is the length from the outer edge Fe to the outer surface boundary point P2. This length L1 is measured along the face normal direction. The face normal direction is the direction of the normal D1 at the midpoint Pa (see Fig. 7). Therefore, the face normal direction is perpendicular to the tangent line Ta and also perpendicular to the straight line Tb. Fig. 9 shows the length L11 of the sole-side peripheral portion 34. Fig. 7 shows the length L12 of the crown-side peripheral portion 36. The lengths L11 and L12 are examples of the length L1.

[0046] As shown in FIG. 7, the sole-side peripheral portion 34 has a length L2 in the face-back direction. The length L2 is the length from the sole-side outer edge Fe to the sole-side outer surface boundary point P2. The crown-side peripheral portion 36 has a length L3 in the face-back direction. The length L3 is the length from the crown-side outer edge Fe to the crown-side outer surface boundary point P2. The length L3 is greater than the length L2. In this disclosure, the length L1 of the peripheral portion 32 is defined as the length in the face normal direction, not the face-back direction lengths L2 and L3 (see the double-headed arrow L1 in FIG. 7 and FIG. 9).

[0047] In Fig. 9, the length of the rear extension 38 is indicated by a double-headed arrow L4. The rear extension 38 has a length L4. The length L4 is the length from the straight line Tb to the end point P2. This length L4 is measured along the face normal direction. In Fig. 9, the length L41 of the sole-side rear extension 40 is shown. In Fig. 7, the length L42 of the crown-side rear extension 42 is shown. The lengths L41 and L42 are examples of the length L4.

[0048] When the face member f1 and the body member b1 are welded, the boundary surface k2 may become unclear. Although not shown, a welded portion is formed in the vicinity of the boundary surface k2 by welding, which melts once and then solidifies. Although not shown, the vertical cross section of this welded portion has an indefinite shape and has a width.

[0049] Due to this weld, the boundary surface k2 may be unclear. When the boundary surface k2 is unclear, both end points P1 and P2 of the cross-sectional boundary line k3 may be unclear. In this case, the points P1 and P2 may be determined as follows. As shown in FIG. 9, in the longitudinal section, the end point P3 of the weld bead wb on the face side and the end point P5 of the weld bead wb on the body side are determined. Furthermore, the midpoint of the line segment connecting the points P3 and P5 is determined. This midpoint is defined as the point P1. Meanwhile, the point P2 may be defined as the midpoint of the cross-sectional line of the weld exposed on the outer surface of the head 4. The point P2 may be determined as the midpoint of the cross-sectional line, which is a curve. The line segment connecting the points P1 and P2 may be the cross-sectional boundary line k3 in the longitudinal section. By identifying the cross-sectional boundary line k3, the dimensions, etc. of the face member f1 in the welded state may be identified. Normally, a weld bead is also formed on the outer surface of the head 4, but this outer weld bead is removed by grinding.

[0050] Point P1 is the center point of the weld bead wb and is also called the bead center point. Point P2 is also called the outer surface boundary point.

[0051] In the longitudinal section, points P4 and P6 are determined on the outer surface of the head 4 (see FIG. 9). Point P4 corresponds to end point P3 on the face side of the weld bead wb. Point P6 corresponds to end point P5 on the body side of the weld bead wb.

[0052] In the longitudinal section, a point P7 is determined on the inner surface of the head 4 (see FIG. 8). The point P7 corresponds to the outer edge Fe of the striking face 10a. The straight line connecting the outer edge Pe and point P7 constitutes the outer edge of the face portion 10.

[0053] In the longitudinal section, a point P9 is determined on the inner surface of the head 4 (see FIG. 8). Point P9 is a point 6 mm away from the bead center point P1 toward the body member b1. This 6 mm is the path distance along the section line. In other words, 6 mm is the length of the section line from point P1 to point P9. In the longitudinal section, a point P8 is determined on the outer surface of the head 4. Point P8 corresponds to point P9.

[0054] Although FIG. 8 shows only the vicinity of the sole-side peripheral edge 34, points P1 to P9 are also defined in the vicinity of the crown-side peripheral edge 36.

[0055] As shown in FIG. 8, the head 4 has a face-side weld vicinity 50 and a body-side weld vicinity 52. ​​The face-side weld vicinity 50 is the weld vicinity of the face member f1. The face-side weld vicinity 50 is the portion from the outer edge Fe of the striking face 10a to the weld bead wb. The body-side weld vicinity 52 is the weld vicinity of the body member b1. The body-side weld vicinity 52 is the portion from a point 6 mm away from the bead center point P1 on the body side to the weld bead wb. On the sole side, the outer surface of the body-side weld vicinity 52 forms part of the sole outer surface 14a.

[0056] The inner surface 50b of the face-side weld vicinity 50 is the region from end point P3 to point P7. The outer surface 50a of the face-side weld vicinity 50 is the region from point P4 to the outer edge Fe. The inner surface 52b of the body-side weld vicinity 52 is the region from end point P5 to point P9. The outer surface 52a of the body-side weld vicinity 52 is the region from point P6 to point P8. The outer surface of the body-side weld vicinity 52 includes the outer surface boundary point P2.

[0057] A thick joint 54 is formed between the face side weld proximate portion 50 and the body side weld proximate portion 52. The outer surface of the thick joint 54 is the region from point P4 to point P6. The inner surface of the thick joint 54 is the surface of the weld bead wb. The face side weld proximate portion 50 and the body side weld proximate portion 52 are connected by the thick joint 54.

[0058] A similar structure is formed on the crown side. As shown in Fig. 7, in a longitudinal section, the head 4 has a face side weld vicinity 50 and a body side weld vicinity 52 on the crown side. The outer surface of the body side weld vicinity 52 on the crown side constitutes a part of the crown outer surface 12a. A thick joint 54 is formed between the face side weld vicinity 50 and the body side weld vicinity 52.

[0059] 9, the thickness t1 of the face side weld vicinity 50 becomes thinner with increasing distance from the face portion 10. The thickness t1 becomes thinner continuously with increasing distance from the face portion 10. The thickness t1 may become thinner in a stepwise manner with increasing distance from the face portion 10.

[0060] 9, the thickness t2 of the body side weld vicinity 52 becomes thinner with increasing distance from the face portion 10. The thickness t2 becomes thinner continuously with increasing distance from the face portion 10. The thickness t2 may become thinner in a stepwise manner with increasing distance from the face portion 10.

[0061] In addition, with regard to the thickness, the term "gradual" does not necessarily include a stepped shape. In other words, the concept of "gradual" includes a configuration in which a portion with a constant thickness and a portion with a continuously changing thickness are connected without any steps.

[0062] The thickness t1 includes the thickness t11 at the end point P3 on the face side of the weld bead wb. The thickness t11 is the length of the line segment connecting the point P3 and the point P4. The thickness t11 is the thickness at the end point P3 on the face side of the weld bead wb. The thickness t11 is the minimum value of the thickness t1.

[0063] The thickness t2 includes the thickness t21 at the end point P5 of the weld bead wb on the body side. The thickness t21 is the length of the line segment connecting the points P5 and P6. The thickness t21 is the thickness of the weld bead wb at the end point P5 on the body side. The thickness t21 is the maximum value of the thickness t2.

[0064] A thickness t11 at an end point P3 on the face side of the weld bead wb is greater than a thickness t21 at an end point P5 on the body side of the weld bead wb.

[0065] The inner surface of the face side weld proximate portion 50 forms a smoothly continuous curved surface. The inner surface of the face side weld proximate portion 50 has a radius of curvature within a predetermined range. The inner surface of the body side weld proximate portion 52 forms a smoothly continuous curved surface. The inner surface of the body side weld proximate portion 52 has a radius of curvature within a predetermined range. The outer surfaces of the face side weld proximate portion 50 and the body side weld proximate portion 52 are continuous via the outer surface of the thick joint portion 54. These outer surfaces are smoothly continuous with a radius of curvature within a predetermined range.

[0066] As shown in Fig. 7, the face portion 10 has a maximum thickness tmax and a minimum thickness tmin. The maximum thickness tmax is the maximum value of the thickness of the face portion 10. The minimum thickness tmin is the minimum value of the thickness of the face portion 10. Although the maximum thickness tmax and the minimum thickness tmin are shown in Fig. 7, in reality, the maximum thickness tmax and the minimum thickness tmin may not exist in a vertical cross section passing through the face center Fc.

[0067] The head 4 provides the following functions and effects.

[0068] The face member f1 is a cup-shaped face and has a peripheral portion 32. Therefore, there is no weld in the face portion 10. In the weld, the thickness increases due to the presence of the weld bead, and the rigidity increases. Therefore, if there is a weld in the face portion 10, the deflection of the face portion 10 can be suppressed due to the weld. Since there is no weld in the face portion 10 of the face member f1, the entire face portion 10 is prone to deflection.

[0069] In the head 4, the length L1 of the peripheral portion 32 is set to be short, 6 mm or less. Therefore, the welded portion between the face member f1 and the body member b1 is disposed near the boundary between the face portion 10 and the crown portion 12. Also, the welded portion between the face member f1 and the body member b1 is disposed near the boundary between the face portion 10 and the sole portion 14. A weld bead that rises on the inner surface of the head is formed in this welded portion. This configuration increases the rigidity in the vicinity of the boundary portion of the face portion 10 (the boundary portion between the face portion and the crown portion or the sole portion). Therefore, the boundary between the face portion 10 and the crown portion 12 and the boundary between the face member f1 and the sole portion 14 are less likely to bend. As a result, the starting point of bending at the time of impact can be moved toward the body side (back side).

[0070] A thickness t11 at an end point P3 on the face side of the weld bead wb is greater than a thickness t21 at an end point P5 on the body side of the weld bead wb. This increases the rigidity on the side closer to the face portion 10, and allows the starting point of bending upon impact to move toward the body side.

[0071] By moving the starting point of bending toward the body side, the bending at the time of impact reaches the body member b1, which is far from the face portion 10. Therefore, the deformation of the body member b1 (crown portion 12, sole portion 14) increases the overall displacement of the face portion 10 compared to when the boundary portion of the face portion 10 bends. As a result, the repulsion performance is improved. This effect is also called the body bending effect.

[0072] From the viewpoint of the body deflection effect, the length L1 of the peripheral portion 32 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and more preferably 5.0 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L1 is preferably 2.5 mm or more, more preferably 2.7 mm or more, and more preferably 3.0 mm or more.

[0073] From the viewpoint of the body deflection effect on the sole side, the length L11 of the sole-side peripheral portion 34 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and more preferably 5.0 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L11 is preferably 2.5 mm or more, more preferably 2.7 mm or more, and more preferably 3.0 mm or more.

[0074] From the viewpoint of the body deflection effect on the crown side, the length L12 of the crown side peripheral portion 36 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and more preferably 5.0 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L12 is preferably 2.5 mm or more, more preferably 2.7 mm or more, and more preferably 3.0 mm or more.

[0075] If the weld bead wb is too close to the face portion 10, deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L1 of the peripheral portion 32 is preferably greater than the minimum thickness tmin, and more preferably greater than the maximum thickness tmax.

[0076] On the sole side, if the weld bead wb is too close to the face portion 10, deformation of the face portion 10 on the sole side may be suppressed. From this viewpoint, the length L11 of the sole-side peripheral portion 34 is preferably greater than the minimum thickness tmin of the face portion 10, and more preferably greater than the maximum thickness tmax.

[0077] On the crown side, if the weld bead wb is too close to the face portion 10, deformation of the face portion 10 on the crown side may be suppressed. From this viewpoint, the length L12 of the crown side peripheral portion 36 is preferably greater than the minimum thickness tmin, and more preferably greater than the maximum thickness tmax.

[0078] From the viewpoint of the body deflection effect, the length L4 of the rear extension portion 38 is preferably 3.3 mm or less, more preferably 3.0 mm or less, and more preferably 2.8 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L4 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and more preferably 0.9 mm or more.

[0079] From the viewpoint of the body deflection effect on the sole side, the length L41 of the sole-side rearward extension portion 40 is preferably 3.3 mm or less, more preferably 3.0 mm or less, and more preferably 2.8 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L41 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and more preferably 0.9 mm or more.

[0080] From the viewpoint of the body deflection effect on the crown side, the length L42 of the crown side rear extension portion 42 is preferably 3.3 mm or less, more preferably 3.0 mm or less, and more preferably 2.8 mm or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the length L42 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and more preferably 0.9 mm or more.

[0081] From the viewpoint of the body deflection effect, the length L4 of the rear extension 38 is preferably smaller than the maximum thickness tmax, and more preferably smaller than the minimum thickness tmin. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, it is preferable that the rear extension 38 exists.

[0082] From the viewpoint of the body deflection effect on the sole side, the length L41 of the sole-side rear extension 40 is preferably smaller than the maximum thickness tmax, and more preferably smaller than the minimum thickness tmin. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, it is preferable that the sole-side rear extension 40 exists.

[0083] From the viewpoint of the body deflection effect on the crown side, the length L42 of the crown side rear extension 42 is preferably smaller than the maximum thickness tmax, and more preferably smaller than the minimum thickness tmin. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, it is preferable that the crown side rear extension 42 exists.

[0084] L4 / L1 is the ratio of the length L4 of the rear extension portion 38 to the length L1 of the peripheral portion 32. From the viewpoint of the body deflection effect, L4 / L1 is preferably equal to or less than 0.55, more preferably equal to or less than 0.5, and more preferably equal to or less than 0.45. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 becomes easily bent. From this viewpoint, L4 / L1 is preferably equal to or more than 0.08, more preferably equal to or more than 0.1, and more preferably equal to or more than 0.15.

[0085] L41 / L11 is the ratio of the length L41 of the sole-side rear extension portion 40 to the length L11 of the sole-side peripheral portion 34. From the viewpoint of the body deflection effect on the sole side, L41 / L11 is preferably 0.55 or less, more preferably 0.5 or less, and more preferably 0.45 or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed and the boundary portion of the face portion 10 is easily bent. From this viewpoint, L41 / L11 is preferably 0.08 or more, more preferably 0.1 or more, and more preferably 0.15 or more.

[0086] L42 / L12 is the ratio of the length L42 of the crown-side rearward extending portion 42 to the length L12 of the crown-side peripheral portion 36. From the viewpoint of the body deflection effect on the crown side, L42 / L12 is preferably 0.55 or less, more preferably 0.5 or less, and more preferably 0.45 or less. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed and the boundary portion of the face portion 10 is easily bent. From this viewpoint, L42 / L12 is preferably 0.08 or more, more preferably 0.1 or more, and more preferably 0.15 or more.

[0087] The thickness t1 of the face-side weld vicinity 50 becomes thinner as it moves away from the face portion 10 (see FIG. 9). This allows the starting point of bending at the time of impact to be moved more effectively to the back side. It is preferable that the thickness t1 becomes thinner continuously or stepwise as it moves away from the face portion 10, and it is more preferable that the thickness t1 becomes thinner continuously as it moves away from the face portion 10.

[0088] From the viewpoint of suppressing bending of the face side weld vicinity portion 50 and shifting the starting point of bending at the time of impact to the back side, the thickness t1 is preferably 1.2 mm or more, more preferably 1.3 mm or more, and more preferably 1.4 mm or more. From the viewpoint of proper thickness distribution from the face portion 10 to the body member b1 and shifting the starting point of bending to the back side, the thickness t1 is preferably 2.0 mm or less, more preferably 1.8 mm or less, and more preferably 1.6 mm or less. The thickness t1 is preferably smaller than the maximum thickness tmax of the face portion 10, and more preferably smaller than the minimum thickness tmin of the face portion 10.

[0089] The thickness t2 of the body side weld vicinity 52 becomes thinner as it moves away from the face portion 10 (see FIG. 9). Therefore, the starting point of bending at the time of impact can be more effectively moved toward the body side (back side). It is preferable that the thickness t2 becomes thinner continuously or stepwise as it moves away from the face portion 10, and it is more preferable that the thickness t2 becomes thinner continuously as it moves away from the face portion 10.

[0090] From the viewpoint of suppressing bending of the body side weld vicinity portion 52 and shifting the starting point of bending at the time of impact to the back side, the thickness t2 is preferably 0.8 mm or more, more preferably 0.9 mm or more, and more preferably 1.0 mm or more. From the viewpoint of proper thickness distribution from the face portion 10 to the body member b1 and shifting the starting point of bending to the back side, the thickness t2 is preferably 1.8 mm or less, more preferably 1.6 mm or less, and more preferably 1.4 mm or less. The thickness t2 is preferably smaller than the maximum thickness tmax of the face portion 10, and more preferably smaller than the minimum thickness tmin of the face portion 10. The thickness t2 is preferably smaller than the thickness t11 at the end point on the face side of the weld bead wb.

[0091] By increasing the radius of curvature of the inner surface 50b of the face-side weld vicinity 50, bending deformation at the face-side weld vicinity 50 is suppressed. Therefore, the starting point of bending at the time of impact can be more effectively moved toward the body side (back side) (see FIG. 8). From this viewpoint, the radius of curvature of the inner surface 50b is preferably 6 mm or more, more preferably 7 mm or more, and more preferably 8 mm or more. If this radius of curvature is too large, the vertical width from the outer edge Fe of the striking face 10a to the sole portion 14 becomes too large, and the vertical width of the striking face 10a becomes small. From this viewpoint, the radius of curvature of the inner surface 50b is preferably 34 mm or less, more preferably 32 mm or less, and more preferably 29 mm or less.

[0092] By increasing the radius of curvature of the outer surface 50a of the face-side weld vicinity 50, bending deformation at the face-side weld vicinity 50 is suppressed. Therefore, the starting point of bending at the time of impact can be more effectively moved toward the body side (back side) (see FIG. 8). From this viewpoint, the radius of curvature of the outer surface 50a is preferably 7 mm or more, more preferably 8 mm or more, and more preferably 9 mm or more. If this radius of curvature is too large, the vertical width from the outer edge Fe of the striking face 10a to the sole portion 14 becomes too large, and the vertical width of the striking face 10a becomes small. From this viewpoint, the radius of curvature of the outer surface 50a is preferably 35 mm or less, more preferably 33 mm or less, and more preferably 30 mm or less.

[0093] Increasing the radius of curvature of the inner surface 52b of the body-side weld vicinity 52 allows the starting point of bending at the time of impact to be more effectively moved toward the body side (back side) (see FIG. 8). From this viewpoint, the radius of curvature of the inner surface 52b is preferably 7 mm or more, more preferably 8 mm or more, and more preferably 9 mm or more. If this radius of curvature is too large, the continuity of the curved shape from the face-side weld vicinity 50 to the sole portion 14 may be impaired. From this viewpoint, the radius of curvature of the inner surface 52b is preferably 34 mm or less, more preferably 32 mm or less, and more preferably 29 mm or less.

[0094] By increasing the radius of curvature of the outer surface 52a of the body side weld vicinity 52, the starting point of bending at the time of impact can be more effectively moved toward the body side (back side) (see FIG. 8). From this viewpoint, the radius of curvature of the outer surface 52a is preferably 7 mm or more, more preferably 8 mm or more, and more preferably 9 mm or more. If this radius of curvature is too large, the continuity of the curved shape from the face side weld vicinity 50 to the sole portion 14 may be impaired. From this viewpoint, the radius of curvature of the outer surface 52a is preferably 35 mm or less, more preferably 33 mm or less, and more preferably 30 mm or less.

[0095] As described above, in the reference state, the head 4 is placed on the ground plane HP. In a vertical section passing through the face center Fc, the outer boundary point P2 is not in contact with the ground plane HP (see FIG. 7). In a vertical section passing through the face center Fc, the outer boundary point P2 is floating above the ground plane HP. In FIG. 7, the double-headed arrow L5 indicates the distance between the ground plane HP and the outer boundary point P2 in the vertical section passing through the face center Fc. This distance is measured along a direction perpendicular to the ground plane HP. From the viewpoint of the body deflection effect, the distance L5 is preferably 1.2 mm or more, more preferably 1.4 mm or more, and more preferably 1.6 mm or more. If the weld bead wb is too close to the face portion 10, the deformation of the face portion 10 is suppressed, and the boundary portion of the face portion 10 is easily bent. From this viewpoint, the distance L5 is preferably 5.0 mm or less, more preferably 4.5 mm or less, and more preferably 4.0 mm or less.

[0096] As described above, the above-mentioned longitudinal sections are set at each position in the toe-heel direction. The above-mentioned shape expands in the toe-heel direction, thereby enhancing the body deflection effect. All of the above-mentioned configurations are preferably satisfied in a longitudinal section passing through the face center Fc, more preferably in any longitudinal section between 10 mm on the toe side of the face center Fc and 10 mm on the heel side, more preferably in any longitudinal section between 15 mm on the toe side of the face center Fc and 15 mm on the heel side, and more preferably in any longitudinal section between 20 mm on the toe side of the face center Fc and 20 mm on the heel side.

[0097] From the viewpoint of transmitting the force applied to the face portion 10 by collision with the ball to the crown portion 12 and deforming the crown portion 12, it is preferable that the angle formed by the face portion 10 and the crown portion 12 is close to a right angle. From the viewpoint of transmitting the force applied to the face portion 10 by collision with the ball to the sole portion 14 and deforming the sole portion 14, it is preferable that the angle formed by the face portion 10 and the sole portion 14 is close to a right angle. From these viewpoints, it is preferable that the loft angle is small. The real loft angle is preferably 16 degrees or less, more preferably 15 degrees or less, and more preferably 14 degrees or less. From the viewpoint of an appropriate launch angle, the real loft angle is preferably 7 degrees or more, more preferably 7.5 degrees or more, and more preferably 8 degrees or more.

[0098] Regarding the above-described embodiment, the following notes are disclosed. [Appendix 1] A hollow golf club head having an outer head surface and an inner head surface, a body member having an opening; a face member having a striking face and closing the opening; It is equipped with the face member has a face portion constituting the striking face and a peripheral portion extending from an outer edge of the face portion toward a back side, the peripheral portion of the face member is welded to the body member; a weld bead is formed on the inner surface of the head at a boundary between the peripheral edge and the body member, a thickness of the weld bead at an end point on a face side is greater than a thickness of the weld bead at an end point on a body side; The length of the peripheral portion is 6 mm or less. Golf club head. [Appendix 2] 2. The golf club head according to claim 1, wherein the peripheral portion has a rearward extension portion that protrudes toward the back side further than the face portion. [Appendix 3] A portion between an outer edge of the face portion and the weld bead is defined as a face-side weld vicinity portion, When the area between the point 6 mm away from the center point of the weld bead on the body side and the weld bead is defined as the body side weld vicinity, The thickness of the face side weld vicinity portion becomes thinner as it moves away from the face portion, 3. The golf club head according to claim 1, wherein the thickness of the body side portion in the vicinity of the weld becomes thinner as it moves away from the face portion. [Appendix 4] The radius of curvature of the inner surface of the face side weld vicinity is 7 mm or more, 4. The golf club head according to claim 3, wherein the radius of curvature of the outer surface of the face side near the weld is 7 mm or more. [Appendix 5] 5. The golf club head according to claim 1, wherein the length of the peripheral portion is greater than the minimum thickness of the face portion. [Appendix 6] 6. The golf club head according to claim 1, wherein the peripheral portion is a sole-side peripheral portion formed on a sole side of the face member. [Explanation of symbols]

[0099] 4. Golf club head 10. Face section 10a···Striking face 12 Crown section 14 Sole part 32... Periphery 34 Sole side edge 36 Crown side periphery 38... Rear extension part 40...Sole side rear extension part 42... Crown side rear extension part 50: Face side near weld 52 Body side weld vicinity f1: Face member b1 Body part wb...weld bead Fc···Face Center Fe: Outer edge of the striking face P1: Bead center point P2...External boundary point

Claims

1. A hollow golf club head having an outer head surface and an inner head surface, a body member having an opening; a face member having a striking face and closing the opening; Equipped with the face member has a face portion constituting the striking face and a peripheral portion extending from an outer edge of the face portion toward a back side, the peripheral portion of the face member is welded to the body member; a weld bead is formed on the inner surface of the head at a boundary between the peripheral edge and the body member, a thickness of the weld bead at an end point on a face side is greater than a thickness of the weld bead at an end point on a body side; The length of the peripheral portion is 6 mm or less, A portion between an outer edge of the face portion and the weld bead is defined as a face-side weld vicinity portion, When the area between the point 6 mm away from the center point of the weld bead on the body side and the weld bead is defined as the body side weld vicinity, The thickness of the face side weld vicinity portion becomes thinner as it moves away from the face portion, The thickness of the body side weld vicinity portion becomes thinner as it moves away from the face portion, The radius of curvature of the inner surface of the face side weld vicinity is 7 mm or more, The radius of curvature of the outer surface of the face side near the weld is 7 mm or more.

2. 2. The golf club head according to claim 1, wherein the peripheral portion has a rearward extending portion that protrudes rearward beyond the face portion.

3. 3. The golf club head according to claim 1, wherein the length of the peripheral portion is greater than the minimum thickness of the face portion.

4. 4. The golf club head according to claim 1, wherein the peripheral portion is a sole-side peripheral portion formed on a sole side of the face member.

Images