Iron golf club head

Abstract

An iron golf club head comprises a face member having a striking face and a back surface, a head main body. The head main body comprises: a receiving surface supporting a peripheral portion of the back surface of the face member; a frame portion extending annularly so as to form a cavity on the back surface side of the face member; and a hosel defining a virtual hosel central axis. In a rear view of the head viewed in a direction perpendicular to the striking face, a shortest distance D between the virtual hosel central axis and a cavity contour line is not more than 16 mm. The cavity contour line is a contour line of the cavity defined in a cross section of the head main body taken along a virtual plane parallel to the striking face and positioned 3 mm rearward from the receiving surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an iron golf club head.BACKGROUND ART

[0002] Many golfers attempt to hit the ball with the face center of the golf club head. In general, the face center is understood to be the midpoint in the toe-heel direction of the range where the score lines (or face lines) are formed in the face. On the other hand, the sweet spot is known as the most effective hitting position for increasing the initial velocity of the hit ball. Incidentally, the sweet spot is an intersecting point where a normal line drawn from the center of gravity of the head to the striking face intersects with the striking face (see Patent Document 1 for related technology).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-049186ASUMMARY OF THE INVENTIONProblems to be Solved by the Invention

[0004] For a golf club head, it is preferable that, in the toe-heel direction, the sweet spot is located at the same position as the face center.

[0005] In a typical iron golf club head, however, the center of gravity of the head, and therefore the sweet spot, tends to be located on the heel side of the face center since a large weight such as of the hosel is located on the heel side, and due to constraints in weight distribution design such as lowering the center of gravity and optimizing the moment of inertia within a limited head weight. In such a case, the golfer's general hitting position will not coincide with the sweet spot in the toe-heel direction. For this reason, there is still room for improvement in increasing the initial velocity of the struck ball.

[0006] The present disclosure was made in view of the above-described problems, and a primarily objective of the present disclosure is to provide an iron golf club head in which, in the toe-heel direction, the position of the sweet spot can be moved closer to the position of the face center.Means for Solving the Problems

[0007] According to the present disclosure, an iron golf club head comprises:

[0008] a face member and

[0009] a head main body supporting the face member,the face member comprising

[0010] a striking face for striking a ball, and

[0011] a back surface opposite the striking face,the head main body comprising

[0012] a receiving surface supporting a peripheral portion of the back surface of the face member,

[0013] a frame portion extending annularly so as to form a cavity on the back surface side of the face member, and

[0014] a hosel extending upward from a heel side portion of the frame portion and defining a virtual hosel central axis,wherein

[0015] in a rear view of the head viewed in a direction perpendicular to the striking face, a shortest distance D between the virtual hosel central axis and a cavity contour line is not more than 16 mm, wherein the cavity contour line is a contour line of the cavity which is defined in a cross section of the head main body taken along a virtual plane being parallel to the striking face and positioned 3 mm away from the receiving surface toward the rear side of the head.Effects of the Invention

[0016] In the iron golf club head according to the present disclosure, by adopting the above-described configuration, it becomes possible to move the position of the sweet spot closer to the position of the center of the striking face in the toe-heel direction.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a front view of an iron golf club head as an embodiment of the present disclosure placed in its reference state.

[0018] FIG. 2 is a rear view of the iron golf club head shown in FIG. 1.

[0019] FIG. 3 is a side view of the iron golf club head shown in FIG. 1 as viewed from the toe side of the head.

[0020] FIG. 4 is a cross-sectional view of the iron golf club head taken along line IV-IV in FIG. 1.

[0021] FIG. 5 is an exploded perspective view of the iron golf club head shown in FIG. 1.

[0022] FIG. 6 is a cross-sectional view of the face member taken along line VI-VI in FIG. 5.

[0023] FIG. 7 is a cross-sectional view of the head main body taken along line VII-VII in FIG. 4.

[0024] FIG. 8 is a perspective view of the partially cut off head main body shown in FIG. 7.

[0025] FIG. 9 is a rear view of the head main body as viewed from a direction perpendicular to the striking face.

[0026] FIG. 10 is a cross-sectional view of the head main body taken along line X-X in FIG. 9.

[0027] FIG. 11 is a cross-sectional view of the iron golf club head taken along line XI-XI in FIG. 1.

[0028] FIG. 12 is an exploded perspective view of another example of the head main body.

[0029] FIG. 13 is a rear view of the head main body shown in FIG. 12.

[0030] FIG. 14 is a rear view of an iron golf club head as another embodiment.

[0031] FIG. 15 is an exploded perspective view of the iron golf club head shown in FIG. 14.

[0032] FIG. 16 is a cross-sectional view of the iron golf club head taken along line XVI-XVI in FIG. 14.

[0033] FIG. 17 is a schematic perspective view of an iron golf club head for explaining the reference state of the head and directions relating to the head.DETAILED DESCRIPTION OF THE INVENTION

[0034] Embodiments of the present disclosure will now be described in detail in conjunction with accompanying drawings.

[0035] The drawings may contain exaggerations and dimensional ratios different from the actual ratios in order to aid the understanding of the present disclosure.For the different embodiments, the same reference numerals are assigned to the same or common parts, and duplicate explanations are omitted.The specific configurations illustrated in the embodiments and the drawings are for understanding the present disclosure, and the present disclosure is not limited to such specific configurations.

[0036] FIGS. 1 to 3 are a front view, a rear view and a side view from the toe side, respectively, of an iron golf club head 1 as an embodiment of the present disclosure (hereinafter, sometimes simply referred to as the head 1).FIG. 4 is a cross-sectional view of the head 1 taken along line IV-IV in FIG. 1.FIG. 5 is an exploded perspective view of the head 1.In FIGS. 1 to 3, shown is the head 1 placed in its reference state.<Reference State>

[0037] In this application including the specification and claims, the “reference state” means a state of a golf club head in which, as shown in FIG. 17, the head is placed on a horizontal plane HP;

[0038] a virtual hosel central axis CL of a hosel 7 of the head (corresponding to the shaft center line of a club shaft attached to the hosel) lies within a reference vertical plane VP which is a plane perpendicular to the horizontal plane HP; face lines 8 formed in a face 2 of the head become parallel to the horizontal plane HP and parallel to the reference vertical plane VP.

[0039] In this specification and claims, unless otherwise noted, the descriptions relating to the golf club head are made based on the head under its reference state.<Directions Relating to Golf Club Head>

[0040] In FIG. 17, the golf club head is placed in the xyz coordinate system associated with the reference state, wherein the xy plane corresponds to the horizontal plane HP, the yz plane corresponds to the reference vertical plane VP, the x axis is parallel to the horizontal plane HP and perpendicular to the reference vertical plane VP, and the y axis is parallel to the horizontal plane HP and the reference vertical plane VP.The “front-back direction” of the head is a direction parallel to the x axis, the “toe-heel” direction of the head is a direction parallel to the y axis, and the “up-down” direction of the head is a direction parallel to the z axis.The expression “front side” of the head refers to the side of the striking face.The expression “rear side” or “back side” of the head refers to the opposite side to the “front side”.The expression “upper side” of the head refers to the side away from the horizontal plane HP.The expression “lower side” of the head refers to the opposite side to the “upper side”.The “lower surface” of the head is referred to as the bottom surface, sole, or sole surface.In FIG. 17, α and β are the loft angle and lie angle, respectively, specified for the head.<Basic Shape of Golf Club Head>

[0041] As shown in FIGS. 1 to 5, the head 1 in the present embodiment has a shape of a typical iron club head, and comprises a face 2, a top 3, a sole 4, a toe 5, a heel 6 and a hosel 7.The face 2 is a front surface of the head including a surface for striking the ball.The top 3 is an upper surface portion of the head extending from the upper edge of the face 2 toward the rear side of the head.The sole 4 is a bottom surface portion of the head extending from the lower edge of the face 2 toward the rear side of the head.The toe 5 is an end portion of the head being opposite the hosel 7 in the toe-heel direction.The heel 6 is a portion being opposite to the toe 5 in the toe-heel direction and opposite to the hosel 7 in the up-down direction of the head.

[0042] The head 1 in the present embodiment is composed of a face member 100 and a head main body 200 supporting the face member 100.The face member 100 and the head main body 200 are made of different metal materials in this embodiment.<Face Member>

[0043] FIG. 6 is a cross-sectional view of the face member 100 of the present embodiment taken along line VI-VI in FIG. 5.As shown in FIGS. 5 and 6, the face member 100 is formed in the form of a plate, and has a front surface defining a striking face 101 for striking the ball, a back surface 102 opposite thereto, and an outer peripheral side surface 103 extending therebetween.The striking face 101 is provided with face lines 8, namely, fine grooves in order to increase friction between the striking face and the ball.The face lines 8 extend in parallel to each other and parallel to the toe-heel direction. Except for such face lines 8, the striking face 101 is formed as a flat surface in substance.

[0044] The contour shape and size of the face member 100 can be determined as appropriate as long as the striking face 101 can secure a sufficient area in the face 2.As shown in FIG. 1, the face member 100 has a top-side edge 100A, a sole-side edge 100B, a toe-side edge 100C and a heel-side edge 100D which are continuous and define the boundary of the face member.In the present embodiment, the top-side edge 100A, the sole-side edge 100B and the toe-side edge 100C extend substantially parallel to the contours of the top 3, the sole 4 and the toe 5, respectively.The heel-side edge 100D extends in the up-down direction in a heel side end flat surface portion of the face 2.

[0045] It is preferable that the face member 100 is made of a metal material having a specific gravity smaller than that of the head main body 200.Such metal materials are not particularly limited, but stainless steel, maraging steel, titanium alloys and the like are preferred in view of the rebound performance, durability and the like. Among these, titanium alloys (having a specific gravity of 4.5 or less, for example) are preferred.The face member 100 made of such metal material helps to make the front side of the head lighter and to position the center of gravity of the head further rearward and lower.

[0046] The face member 100 of the present embodiment comprises, as shown in FIG. 6, a central portion 104 having a first thickness t1, and a peripheral thick portion 105 having a second thickness t2 larger than the first thickness t1.

[0047] The central portion 104 forms a wide area, including the sweet spot SS (FIG. 1).In order that the central portion 104 is able to bend largely when hit by the ball, the first thickness t1 is set to a relatively small value. For example, the first thickness t1 is preferably not more than 3.2 mm, more preferably not more than 3.0 mm.On the other hand, in view of the durability of the face member 100 for example, the first thickness t1 is preferably not less than 1.5 mm, more preferably not less than 1.8 mm.Further, it may be possible to provide the back surface 102 in the central portion 104 with a recessed portion 106 in which the first thickness t1 is further reduced from the above-mentioned ranges as a preferable modification.

[0048] The peripheral thick portion 105 is formed along the periphery of the face member 100 so as to surround the central portion 104.In the present embodiment, the peripheral thick portion 105 is continuously and annularly formed.The peripheral thick portion 105 has the second thickness t2 larger than the central portion 104, and accordingly, has a higher bending rigidity than the central portion 104.In the present embodiment, the peripheral thick portion 105 is fixed to the head main body 200 as described later, and thereby, the face member 100 is supported by the head main body 200.The rear surface of the peripheral thick portion 105 may be formed as a flat surface parallel to the striking face 101 as a preferred mode.

[0049] The outer peripheral side surface 103 of the face member 100 is provided, on the front side thereof, with a stepwise recessed portion 103a. The stepwise recessed portion 103a is formed around the face member 100 continuously along the periphery of the face member 100.<Head Main Body>

[0050] The head main body 200 of the present embodiment is made of a metal material having a specific gravity larger than the specific gravity of the metal material of the face member 100. As such metallic material, for example, carbon steel, stainless steel and the like can be preferably used.

[0051] The head main body 200 is provided with an opening 201 for receiving the face member 100 as shown in FIGS. 4 and 5.In the present embodiment, the head main body 200 is provided with a through hole penetrating in the front-back direction, defining the opening 201. The shape of the opening 201 is larger in the toe-heel direction than in the up-down direction, and similar to the contour shape of the face 2 in this example.

[0052] In the through hole, the receiving surface 202 is formed slightly recessed from the opening 201. The receiving surface 202 is for coming into contact with the peripheral portion of the back surface 102 of the face member 100 to support the face member 100.In the present embodiment, the receiving surface 202 contacts with the back surface of the peripheral thick portion 105 of the face member 100.As shown in FIG. 5, the receiving surface 202 is formed annularly along the edge of the opening 201, and continuously supports the toe-side, top-side, heel-side and sole-side portions of the back surface of the peripheral thick portion 105 of the face member 100.In the present embodiment, the receiving surface 202 is formed as a flat surface parallel to the striking face 101 and the back surface of the peripheral thick portion 105 as shown in FIG. 4.

[0053] The head main body 200 has an inner surface 203 of the through hole which extends from the outer peripheral edge of the receiving surface 202 toward the opening 201 as shown in FIG. 4.The inner surface 203 faces and contacts the outer peripheral side surface 103 of the face member 100.Further, the inner surface 203 is provided, in its front portion, with an engaging portion 203a for engaging with the stepwise recessed portion 103a of the outer peripheral side surface 103 so as to hold the face member 100.

[0054] The engaging portion 203a is formed by plastically deforming a part of the head main body 200. Specifically, the face member 100 is temporarily attached to the head main body 200 by fitting it into the through hole from the opening so that the back surface of the peripheral thick portion 105 contacts the receiving surface 202 (At this point, the engaging portion 203a has not yet been formed). Then, a part of the head main body 200 is plastically deformed so as to form the engaging portion 203a which protrudes onto the stepwise recessed portion 103a. Therefore, in the head 1 in the present embodiment, the face member 100 and the head main body 200 are fixed together by a crimping technique such that pressure is applied to the head main body 200 to cause a part thereof to be plastically deformed and thereby mechanically engaged with the face member 100 (engaging portion 203a).

[0055] In the present embodiment, the engaging portion 203a is formed annularly so as to be continuous around the face member 100.Therefore, in the head 1 in the present embodiment, the engaging portion 203a supports and fixes the face member 100 on its toe side, top side, heel side and sole-side.When crimping, an adhesive agent may be used at the same time on the contact surfaces between the face member 100 and the head main body 200. As a means for fixing the face member 100 to the head main body 200, for example, adhesive only, welding, brazing, screw fastening and the like may be employed if possible.

[0056] The head main body 200 of the present embodiment comprises a frame portion 205 and a hosel 7.

[0057] The frame portion 205 extends continuously and annularly, and forms a cavity C on the back surface 102 side of the face member 100. In the present embodiment, as shown in FIG. 5, the frame portion 205 includes a top-side frame portion 205A extending along the top 3,

[0058] a sole-side frame portion 205B extending along the sole 4,

[0059] a toe-side frame portion 205C extending along the toe 5, and

[0060] a heel-side frame portion 205D including the heel 6.From the heel-side frame portion 205D, the hosel 7 extends obliquely upward. The hosel 7 has a hosel bore 7a into which the tip end of the club shaft is inserted and fixed.The center line of the hosel bore 7a corresponds to the virtual hosel central axis CL (shown in FIG. 1).When the head 1 is attached to the club shaft to form an iron golf club, the virtual hosel central axis CL substantially coincides with the shaft center line of the attached club shaft.

[0061] The frame portion 205 located around the cavity C distributes its large amount of weight to the periphery of the face member 100.This increases the moment of inertia of the head, and lowers the position of the center of gravity of the head.The head 1 provided with the back cavity C allows the face member 100 to bend (elastically deform) significantly toward the rear side of the head when hit by the ball, which helps to increase the initial velocity of the struck ball.

[0062] When the head 1 is finished, the cavity C may be an open cavity visible from the rear side of the head, or a closed cavity invisible from the rear side which is covered by a badge having a decorative or design purpose.<Cavity>

[0063] As shown in FIG. 2, the cavity C defined by the head main body 200 extends roughly along the contour of the face 2 and has a shape long in the toe-heel direction.In particular, in the head 1 in the present embodiment, the cavity C is expanded more toward the heel 6.

[0064] In order to quantitatively determine the expansion of the cavity C toward the heel, a cavity contour CC is defined as follows.

[0065] First, as shown in FIG. 4, an virtual plane VP3 is defined.The virtual plane VP3 is parallel to the striking face 101, and located 3 mm behind the head from the position of the receiving surface 202 of the head main body 200.

[0066] When the distance from the striking face 101 to the receiving surface 202 is not constant depending on the position on the receiving surface 202, the above-said position of the receiving surface 202 is determined as the position of the receiving surface 202 which is farthest from the striking face 101.

[0067] Next, on the virtual plane VP3, the cross section of the head main body 200 is determined as shown FIG. 7 (hatched area).Then, the contour line of the cavity C (the internal boundary line of the cross section) is defined as the cavity contour line CC.The cavity contour line CC can be said to be the intersection line between the virtual plane VP3 and the inner surface of the cavity C.

[0068] Since the cavity C is generally formed on the head's rear side of the receiving surface 202, the position of the virtual plane VP3 is set as described above, taking into account the thickness at the receiving surface 202, and the cavity contour line CC is defined.

[0069] FIG. 7 is a cross-sectional view of the head main body 200 taken along the virtual plane VP3, viewed from the rear side of the head in a direction perpendicular to the striking face 101.

[0070] In FIG. 7, the cavity contour line CC is shown by a slightly thicker line.FIG. 8 is a perspective view of the head main body 200 shown in FIG. 7, namely, the head main body whose portion behind the virtual plane VP3 is cut off.

[0071] In the head 1 in the present embodiment, in the rear view of the head, and as shown in FIG. 7, the shortest distance D between the virtual hosel central axis CL and the cavity contour line CC is set to be not more than 16 mm, preferably not more than 15 mm.

[0072] In such head 1, due to the cavity C extended more greatly toward the heel, the weight of the head main body 200 is significantly reduced on the heel side. Thereby, in the head 1 in the present embodiment, the center of gravity of the head is shifted toward the toe, and as a result, the sweet spot SS can be brought closer to the face center FC.Here, the face center FC is, as shown in FIG. 1, defined as the midpoint in the up-down direction between the upper end and the lower end of the face 2 at the midpoint in the toe-heel direction between the most toe-side end 8A and the most heel-side end 8B of the face lines 8.

[0073] Incidentally, the weight of the head main body 200 reduced from the heel side may be utilized as a weight margin usable for optimizing the center of gravity of the head.

[0074] In the present embodiment, as shown in FIG. 7, the entire cavity contour line CC is located on the toe side of the virtual hosel central axis CL. In this case, the above-said shortest distance D is indicated by a positive value.

[0075] The lower limit of the shortest distance D is not particularly limited. But, if the shortest distance D between the virtual hosel central axis CL and the cavity contour line CC is excessively small, the strength of the head main body 200 on the heel 6 side is decreased. As a result, while using the head 1, the lie angle of the head gradually changes, and the durability of the head main body 200 is decreased. From this viewpoint, the shortest distance D may be set to 4 mm or more, preferably 5 mm or more.

[0076] There are iron golf club heads having various loft angles α.When the loft angle α changes, generally, it is necessary to change the club length as well. This requires an appropriate lie angle β to be chosen according to the club length.When the club length changes, the position of the hosel 7 will also change. Specifically, an iron golf club having a larger loft angle α also has a larger lie angle β, and as a result, the virtual hosel central axis CL becomes closer to vertical.For this reason, an iron golf club having a large loft angle α tends to have a relatively large shortest distance D between the virtual hosel central axis CL and the cavity contour line CC as compared to a head with a small loft angle α. Therefore, it is preferable that the shortest distance D is adjusted according to the loft angle α.

[0077] When the head 1 has a loft angle α larger than 35 degrees, the shortest distance D between the virtual hosel central axis CL and the cavity contour line CC is preferably set in a range from 10 to 16 mm.When the head 1 has a loft angle α of not larger than 35 degrees, the shortest distance D between the virtual hosel central axis CL and the cavity contour line CC is preferably set in a range from 6 to 10 mm.Thereby, for each club number of the head, it becomes possible to set an appropriate shortest distance D to make the sweet spot SS closer to the face center FC.

[0078] Preferably, the sweet spot SS of the head 1 may be located on the heel side of the face center FC in the toe-heel direction so that the distance in the toe-heel direction between the face center FC and the sweet spot SS is not more than 5.5 mm, preferably not more than 5.0 mm.Most preferably, the sweet spot SS is located at the same position in the toe-heel direction as the position in the toe-heel direction of the face center FC.

[0079] From another perspective, the shortest distance D may be set in relation to the loft angle of the head.Specifically, the ratio D / α of the shortest distance D in mm to the loft angle α in degree may be preferably set to be not less than 0.25 mm / degree, more preferably not less than 0.26 mm / degree in order to move the sweet spot SS closer to the face center FC.On the other hand, in order to ensure sufficient durability of the head, the ratio D / α may be preferably set to be not more than 0.35 mm / degree, more preferably not more than 0.34 mm / degree.<Rear Support Surface>

[0080] FIG. 9 is a rear view of the head main body 200 viewed from the rear side of the head.FIG. 10 is a cross-sectional view of the head main body 200 taken along line XX of FIG. 9.The above-described receiving surface 202 includes a part on the heel side for supporting the heel side portion of the face member 100 (hereinafter, the heel-side receiving surface 202D).As shown in FIGS. 9 and 10, the head main body 200 has a rear support surface 206 on the rear side of the heel-side receiving surface 202D.The rear support surface 206 is a surface located on the front side of the virtual plane VP3.The rear support surface 206 can support the head main body 200 from the rear side of the head through the cavity C.When the head main body 200 is viewed from the rear side, the rear support surface 206 can be seen.In the present embodiment, the rear support surface 206 is extended toward the heel 6 side further than the heel-side receiving surface 202D.

[0081] Therefore, in the present embodiment, when the face member 100 is fixed to the head main body 200 by crimping, the rear support surface 206 of the head main body 200 can be supported from the rear side by a jig 10 or the like inserted from the rear side through the cavity C.Therefore, a larger pressure can be applied to the head main body 200 from the face 2 side or front side in order that the face member 100 and the head main body 200 can be firmly joined together.The area of the rear support surface 206 (the area in the rear view of FIG. 9) is preferably not less than 100 sq.mm, more preferably not less than 110 sq.mm in order to effectively derive the above-described effect.<Preferred Aspect of Sole>

[0082] In order to shift the position of the center of gravity of the head toward the toe side, it is preferable to specify the dimensions of the head 1, especially on the toe side such that a toe-side portion of the sole 4 has a relatively large dimension in the front-back direction of the head.This helps to position the center of gravity of the head toward the toe side and toward the lower side.FIG. 11 is a cross-sectional view of the head 1 taken along line XI-XI of FIG. 1. The line XI-XI of FIG. 1 is of a vertical plane being perpendicular to the horizontal plane HP, and extending parallel to the front-back direction of the head through the above-mentioned most toe-side end 8A of the face lines 8. As shown in FIG. 11, at the position of the most toe-side end 8A, the dimension SW of the sole 4 measured from the leading edge Le to the trailing edge Te in the front-back direction of the head, is preferably set to be not less than 25 mm, more preferably not less than 28 mm.<Preferred Aspect of Hosel>

[0083] In order to shift the position of the center of gravity of the head toward the toe side, it is preferable to reduce the weight of the hosel 7, for example, such that the outer diameter of the hosel 7 is not more than 13.2 mm, preferably not more than 13.0 mm.Another Embodiment 1

[0084] FIG. 12 shows the head main body 200 of a head as another embodiment of the present disclosure. In this embodiment, as shown in FIG. 12, the head main body 200 is composed of a front member 200A supporting the face member 100, and a rear member 200B fixed to the rear side of the front member 200A, defining at least a part (major part) of the cavity C.Thus, the head main body 200 of the present embodiment is formed by joining the front member 200A and the rear member 200B into which the annular frame portion 205 is divided in the front-back direction.The hosel 7 is formed integrally with the front member 200A.

[0085] By dividing the head main body 200 into the front and rear members 200A and 200B, various modifications can be made to either or both of the joint surfaces of the front and rear member 200A and 200B.

[0086] For example, in order to enhance flexibility at any desired location on the head, the joint surface 200A1 of the front member 200A can be provided, at that desired location, with a groove 210 extending in the toe-heel direction. Further, the joint surface of the rear member 200B (not visible in FIG. 12) can be provided with a recess 212 in which a weight member 214 having a specific gravity larger than that of the head main body 200 is disposed. Thereby, it is easy to mount the weight member 214 inside the head main body 200 integrally, and the center of gravity of the head can be shifted toward the toe side.

[0087] In the present embodiment, the above-mentioned rear support surface 206 is formed on the front member 200A. The cavity contour line CC is defined by the rear member 200B. The virtual plane VP3 shown in FIG. 4 is located in the rear member 200B.

[0088] FIG. 13 is a rear view of the head main body 200 of the present embodiment, viewed from a direction perpendicular to the striking face 101. In the present embodiment, as shown in FIG. 13, the virtual hosel central axis CL intersects with the contour line 216 of the divided face (the joint surfaces) between the rear member 200B and the front member 200A.The cavity contour line CC defined by the cavity C of the rear member 200B extends toward the heel side, and also,the heel-side contour 200B2 of the rear member 200B extends toward the heel side in the rear view of the head.Thereby, the contour line 216 between the rear member 200B and the front member 200A intersects with the virtual hosel central axis CL.Another Embodiment 2

[0090] FIGS. 14 to 16 show a head 1 as another embodiment of the present disclosure. FIG. 14 is a rear view of the head 1. FIG. 15 is an exploded perspective view thereof. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14.In the present embodiment, the head 1 is composed of the face member 100, the head main body 200, and a badge 300 as shown in FIGS. 14 to 16.

[0091] The badge 300 is disposed on the back surface 102 side of the face member 100. In the present embodiment, the badge 300 is fixed to the back surface 102 of the face member 100 via an adhesive means 400 such as double-sided tape.The attached badge 300 fills at least a part of the space of the cavity C. The present embodiment, the attached badge 300 substantially fills an upper part of the space of the cavity C.Specifically, the peripheral edge of the badge 300 is located so as to contact with the edge of the opening of the cavity C of the head main body 200.The badge 300 is typically, a design element which is provided with various designs so as to enhance the decorative effect of the head 1.The badge 300 may be arranged so as to completely or partially close the cavity C on the back surface side of the head in order to prevent large foreign objects from entering the cavity C.

[0092] Preferably, the badge 300 is made of a material having a specific gravity lower than the face member 100 and lower than the head main body 200. In the present embodiment, the badge 300 is mainly made of a resin material so that the badge 300 does not prevent the face member 100 from bending toward the rear side of the head when the face 2 is hit by the ball. Further, since the badge 300 is made of a material having a relatively low specific gravity, the design freedom of the head weight distribution which is made by adjusting the shape of the cavity C is not restricted.

[0093] In the head 1 in the present embodiment, too, the cavity contour line CC is defined by the cross section of the head main body 200 on the virtual plane VP3 which is parallel to the striking face 101 and is located 3 mm toward the rear side of the head from the receiving surface 202 as shown in FIG. 16. Thus, the cavity contour line CC is not affected by the presence or absence of the badge 300.

[0094] While detailed description has been made of preferable embodiments of the present disclosure, the present disclosure can be embodied in various forms without being limited to the illustrated embodiments.Comparison Tests

[0095] Based on the structure shown in FIGS. 1 to 8, various golf club heads for irons (#5-#9) and wedges (PW,AW,SW) were experimentally created as Examples according to the present disclosure and Comparative Examples as shown in Table 1.Then, for each head, the difference (distance) in the toe-heel direction between the sweet spot (SS) and the face center (FC) was measured, wherein the smaller value is better, and a positive value indicates that the sweet spot (SS) is located on the heel side of the face center (FC), and a negative value means the opposite.

[0096] Further, taking #8 iron club head as a representative example, Examples and Comparative Examples were evaluated for the joining characteristics between the face member and the head main body fixed to each other by crimping.To evaluate the joining characteristics, the joint portion between the face member and the head main body was cut at a middle position in the thickness direction of the face member 100, andin the obtained cross-section, the presence or absence of a gap between the face member and the receiving surface on the heel side was observed, and the size of the gap was measured to comprehensively evaluate the joining characteristics.The evaluated results are indicated in Table 1 by an index based on Comparative Example being 100, wherein the larger the value, the smaller the gap, and the better the joining characteristics and quality of the crimping.TABLE 1ShortestRear supportDifferencedistancesurfacebetweenJoiningClubDLoft angle αD / αareaSS and FCcharacteristicsnumber(mm)(deg.)(mm / deg.)(sq. mm)(mm)(index)Comparative#516.0220.7332.33Example#616.5250.6632.99#717.1280.6133.45#819.0320.5904.41100#920.0370.5405.04PW20.7420.4905.24AW21.7480.4505.28SW22.9560.4105.76Example#57.0220.321191.45#67.5250.301211.88#78.3280.301212.32#89.2320.291253.58138#910.3370.281224.02PW11.9420.281264.38AW13.4480.281204.68SW15.0560.271205.11From the test results, it was confirmed that the sweet spot of each Example was closer to the face center as compared with Comparative Example of the same club number.Further, it was confirmed that, with respect to #8 iron head, Example had significantly improved in joining characteristics as compared with Comparative Example. This was presumably because, during crimping, the rear support surface having a large area more than 100 sq.mm could be supported stably and firmly by the jig, and sufficiently large pressure could be applied to the joining portion.STATEMENT OF THE PRESENT DISCLOSUREThe present disclosure is as follows.Present Disclosure 1An iron golf club head comprisesa face member anda head main body supporting the face member,the face member comprisinga striking face for striking a ball, anda back surface opposite the striking face,the head main body comprising

[0103] a receiving surface supporting a peripheral portion of the back surface of the face member,

[0104] a frame portion extending annularly so as to form a cavity on the back surface side of the face member, and

[0105] a hosel extending upward from a heel side portion of the frame portion and defining a virtual hosel central axis,wherein

[0106] in a rear view of the head viewed in a direction perpendicular to the striking face, a shortest distance D between the virtual hosel central axis and a cavity contour line is not more than 16 mm, wherein the cavity contour line is a contour line of the cavity which is defined in a cross section of the head main body taken along a virtual plane being parallel to the striking face and positioned 3 mm away from the receiving surface toward the rear side of the head.Present Disclosure 2The iron golf club head according to Present Disclosure 1, whereina loft angle α of the head is not more than 35 degrees, and

[0108] the shortest distance D is 6 to 10 mm.Present Disclosure 3The iron golf club head according to Present Disclosure 1, whereina loft angle α of the head is more than 35 degrees, and

[0110] the shortest distance D is 10 to 16 mm.Present Disclosure 4The iron golf club head according to Present Disclosure 1, 2 or 3, whereina ratio D / α of the shortest distance D in mm to the loft angle α in degrees is 0.25 to 0.35.Present Disclosure 5The iron golf club head according to any one of Present Disclosures 1 to 4, wherein the face member is fixed to the head main body by an engagement portion engaging an outer peripheral edge of the face member from a striking face side of the face member,the engagement portion is formed by plastically deforming a portion of the head main body,the head main body is provided with a receiving surface supporting a heel side portion of the face member, and a rear support surface formed on a rear side of the receiving surface for supporting the head main body from the rear side of the head through the cavity,

[0114] the rear support surface is extended toward a heel side of the head further than the receiving surface, and

[0115] the area of the rear support surface is not less than 100 sq.mm.Present Disclosure 6The iron golf club head according to Present Disclosure 5, whereinthe rear support surface includes a surface parallel to the striking face.Present Disclosure 7The iron golf club head according to any one of Present Disclosures 1 to 6, wherein the face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.Present Disclosure 8The iron golf club head according to any one of Present Disclosures 1 to 7, wherein the hosel has an outer diameter not more than 13.2 mm.Present Disclosure 9The iron golf club head according to any one of Present Disclosures 1 to 8, wherein the head main body is composed of a front member supporting the face member, and a rear member fixed to the front member on the rear side thereof, defining at least a part of the cavity, andin a rear view of the head viewed in a direction perpendicular to the striking face, the virtual hosel central axis intersects with a contour line of the divided face between the rear member and the front member.Present Disclosure 10The iron golf club head according to Present Disclosure 9, whereinthe rear member is provided with a recess, anda weight member having a specific gravity larger than that of the head main body is disposed in the recess.Present Disclosure 11The iron golf club head according to any one of Present Disclosures 1-10, wherein the face member comprises a central portion having a first thickness of not more than 3.2 mm and not less than 1.5 mm, and a peripheral thick portion around the central portion, having a second thickness larger than the first thickness.Present Disclosure 12The iron golf club head according to any one of Present Disclosures 1-11, wherein a badge made of a material having a specific gravity lower than the face member and lower than the head main body, is disposed so as to at least partially close the cavity from a rear side of the head.DESCRIPTION OF THE REFERENCE SIGNS1 head2 face4 sole5 toe6 heel7 hosel8 face line

[0128] 100 face member

[0129] 101 striking face

[0130] 102 back surface

[0131] 200 head main body

[0132] 200A front member

[0133] 200B rear member

[0134] 202 receiving surface

[0135] 203a engaging portion

[0136] 205 frame portion

[0137] 206 rear support surface

[0138] 216 contour line of divided face

[0139] C cavity

[0140] CC cavity contour line

[0141] CL virtual hosel central axis

[0142] D shortest distance

[0143] VP3 virtual plane

Claims

1. An iron golf club head comprisinga face member anda head main body supporting the face member,the face member comprisinga striking face for striking a ball, anda back surface opposite the striking face,the head main body comprisinga receiving surface supporting a peripheral portion of the back surface of the face member,a frame portion extending annularly so as to form a cavity on the back surface side of the face member, anda hosel extending upward from a heel side portion of the frame portion and defining a virtual hosel central axis, andin a rear view of the head viewed in a direction perpendicular to the striking face, a shortest distance D between the virtual hosel central axis and a cavity contour line is not more than 16 mm, wherein the cavity contour line is a contour line of the cavity which is defined in a cross section of the head main body taken along a virtual plane being parallel to the striking face and positioned 3 mm away from the receiving surface toward the rear side of the head.

2. The iron golf club head according to claim 1, whereina loft angle α of the head is not more than 35 degrees, andthe shortest distance D is 6 to 10 mm.

3. The iron golf club head according to claim 1, whereina loft angle α of the head is more than 35 degrees, andthe shortest distance D is 10 to 16 mm.

4. The iron golf club head according to claim 1, whereina ratio D / α of the shortest distance D in mm to the loft angle α in degrees is 0.25 to 0.35.

5. The iron golf club head according to claim 2, whereina ratio D / α of the shortest distance D in mm to the loft angle α in degrees is 0.25 to 0.35.

6. The iron golf club head according to claim 3, whereina ratio D / α of the shortest distance D in mm to the loft angle α in degrees is 0.25 to 0.35.

7. The iron golf club head according to claim 1, whereinthe face member is fixed to the head main body by an engagement portion engaging an outer peripheral edge of the face member from a striking face side of the face member, the engagement portion formed by plastically deforming a portion of the head main body,the head main body is provided witha receiving surface supporting a heel side portion of the face member, anda rear support surface formed on a rear side of the receiving surface for supporting the head main body from the rear side of the head through the cavity,the rear support surface is extended toward a heel side of the head further than the receiving surface, andthe area of the rear support surface is not less than 100 sq.mm.

8. The iron golf club head according to claim 2, whereinthe face member is fixed to the head main body by an engagement portion engaging an outer peripheral edge of the face member from a striking face side of the face member, the engagement portion formed by plastically deforming a portion of the head main body,the head main body is provided witha receiving surface supporting a heel side portion of the face member, anda rear support surface formed on a rear side of the receiving surface for supporting the head main body from the rear side of the head through the cavity,the rear support surface is extended toward a heel side of the head further than the receiving surface, andthe area of the rear support surface is not less than 100 sq.mm.

9. The iron golf club head according to claim 3, whereinthe face member is fixed to the head main body by an engagement portion engaging an outer peripheral edge of the face member from a striking face side of the face member, the engagement portion formed by plastically deforming a portion of the head main body,the head main body is provided witha receiving surface supporting a heel side portion of the face member, anda rear support surface formed on a rear side of the receiving surface for supporting the head main body from the rear side of the head through the cavity,the rear support surface is extended toward a heel side of the head further than the receiving surface, andthe area of the rear support surface is not less than 100 sq.mm.

10. The iron golf club head according to claim 4, whereinthe face member is fixed to the head main body by an engagement portion engaging an outer peripheral edge of the face member from a striking face side of the face member, the engagement portion formed by plastically deforming a portion of the head main body,the head main body is provided witha receiving surface supporting a heel side portion of the face member, anda rear support surface formed on a rear side of the receiving surface for supporting the head main body from the rear side of the head through the cavity,the rear support surface is extended toward a heel side of the head further than the receiving surface, andthe area of the rear support surface is not less than 100 sq.mm.

11. The iron golf club head according to claim 7, whereinthe rear support surface includes a surface parallel to the striking face.

12. The iron golf club head according to claim 1, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

13. The iron golf club head according to claim 2, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

14. The iron golf club head according to claim 3, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

15. The iron golf club head according to claim 5, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

16. The iron golf club head according to claim 6, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

17. The iron golf club head according to claim 8, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

18. The iron golf club head according to claim 9, whereinthe face member is provided, in its front surface, with face lines extending in a toe-heel direction of the head, andthe head comprises a sole whose dimension measured in a front-back direction of the head at a position in the toe-heel direction corresponding to the most toe-side end of the face lines, is not less than 25 mm.

19. The iron golf club head according to claim 1, whereinthe hosel has an outer diameter not more than 13.2 mm.

20. The iron golf club head according to claim 1, whereinthe head main body is composed ofa front member supporting the face member, anda rear member fixed to the front member on the rear side thereof, defining at least a part of the cavity, andin a rear view of the head viewed in a direction perpendicular to the striking face, the virtual hosel central axis intersects with a contour line of the divided face between the rear member and the front member.

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