Golf club head

Abstract

A golf club head having improved rebound performance by a new construction is provided. The head (4) has a main body member (b1) having an opening (b10), and a face member (f1) having a striking face (10a) and closing the opening (b10). The face member (f1) has a face portion (10) constituting the striking face (10a), and a peripheral portion (32) extending from a peripheral edge of the face portion (10) toward a rear side of the head. In the peripheral portion (32), the face member (f1) is welded to the main body member (b1). A weld bead (wb) protruding on an inner surface of the head (4) is formed at a boundary position of the peripheral portion (32) and the main body member (b1). A wall thickness (t11) at an end point of the weld bead (wb) on the face side is larger than a wall thickness (t21) at an end point of the weld bead (wb) on the main body side. A length (L1) of the peripheral portion (32) is 6 mm or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a golf club head. BACKGROUND

[0002] A golf club head in which a face member is welded to a head main body is known. Also, a golf club head in which a face member has a cup-shaped face structure is known. Japanese Patent Application Publication No. 2020-191938 discloses a golf club head in which a face member having a peripheral edge portion is joined to a head main body by welding. In this head, the peripheral edge portion has a thick wall portion that is joined to an end surface of an opening of the head main body, and a linking portion that links the thick wall portion to the face portion. The linking portion has a thin wall portion that is thinner than the thick wall portion.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-191938 SUMMARY

[0006] It is desirable for a head to have higher rebound performance. The present inventors have discovered a new configuration that can improve rebound performance in a head in which a face member is joined to a main body member. It has been ascertained that rebound performance can be improved by increasing the rigidity of a portion that is easily bent in a conventional configuration, and shifting the position of bending. One object of the present application is to provide a golf club head that can improve rebound performance by a new configuration.

[0007] TECHNICAL MEANS FOR SOLVING THE PROBLEM

[0008] In one aspect, a golf club head has a head outer surface and a head inner surface, and is hollow. The head has a main body member having an opening, and a face member having a striking face and closing the opening. The face member has a face portion that constitutes the striking face, and a peripheral edge portion that extends from an outer edge of the face portion toward a head back side. The peripheral edge portion of the face member is welded to the main body member. A weld bead that protrudes on the head inner surface is formed at a boundary position of the peripheral edge portion and the main body member. A wall thickness at an end point of the weld bead on the face side is greater than a wall thickness at an end point of the weld bead on the main body side. A length of the peripheral edge portion is 6 mm or less.

[0009] EFFECT OF THE INVENTION

[0010] In one aspect, a golf club head is provided that can improve rebound performance by a new configuration. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A golf club having a head of the first embodiment is shown.

[0012] Figure 2 (a) is a front view of the club head of the first embodiment as viewed from the club face side, Figure 2 (b) is a cross-sectional view taken along Figure 2 the E1 line of (a). In Figure 2 (b), only the cross-sectional line of the outer surface of the club head is shown.

[0013] Figure 3 is a plan view of the club head of the first embodiment as viewed from the top side.

[0014] Figure 4 is a bottom view of the club head of the first embodiment as viewed from the sole side.

[0015] Figure 5 is a cross-sectional view taken along Figure 2 the A-A line of (a).

[0016] Figure 6 is an exploded perspective view of the club head of the first embodiment.

[0017] Figure 7 is an enlarged view of the vicinity of the club face portion of Figure 5 (a).

[0018] Figure 8 is an enlarged view of the inside of the circle A of Figure 5 (a).

[0019] Figure 9 is an enlarged view of the inside of the circle B of Figure 8 (a).

[0020] Figure 10 is a conceptual diagram for explaining the reference state.

[0021] Symbol Explanation

[0022] 4 golf club head

[0023] 10 club face portion

[0024] 10a striking face

[0025] 12 crown

[0026] 14 sole

[0027] 32 perimeter portion

[0028] 34 sole-side perimeter portion

[0029] 36 top-side perimeter portion

[0030] 38 rearward extension portion

[0031] 40 sole-side rearward extension portion

[0032] 42. Extension at the rear side of the top of the pole

[0033] 50. Near the welding area on the side of the rod face

[0034] 52. Part near the main body side welding

[0035] f1 clubface components

[0036] b1 Main Components

[0037] wb weld

[0038] Fc Center of the face

[0039] Fe - Outer edge of the striking face

[0040] P1 Weld center point

[0041] P2 is the boundary point on the outer surface. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0043] In this application, the following are defined: reference state, reference vertical plane, clubhead toe-heel direction, clubface-back direction, up-down direction, clubface center, longitudinal section, and radius of curvature.

[0044] The baseline state is the clubhead positioned on the ground plane HP at a specified loft angle. For example... Figure 10 As shown, in this reference state, the shaft axis Z is included in the plane VP perpendicular to the ground plane HP. The shaft axis Z is the centerline of the shaft. The shaft axis Z is the centerline of the neck hole. The plane VP is the reference vertical plane. Specified loft angles are listed, for example, in the product catalog.

[0045] In this baseline state, the clubface angle is 0 degrees. That is, when viewed from above, the tangent at the center of the clubface at impact is parallel to the toe-heel direction. The definitions of the clubface center and the toe-heel direction are as described later.

[0046] In this application, the clubhead toe-heel direction refers to the direction of the intersection line NL of the reference vertical plane VP and the ground contact plane HP (refer to...). Figure 10 The toe side of the clubhead in the toe-heel direction is also simply referred to as the "toe side". The heel side of the clubhead in the toe-heel direction is also simply referred to as the "heel side".

[0047] In the present application, the loft-sole direction is a direction perpendicular to the toe-heel direction of the head with respect to the landing plane HP and parallel to the face-back direction of the head. In other words, in the present application, the loft-sole direction is a direction perpendicular to the landing plane HP.

[0048] In the present application, the vertical direction is a direction perpendicular to the toe-heel direction of the head and perpendicular to the loft-sole direction. In other words, in the present application, the vertical direction is a direction perpendicular to the landing plane HP.

[0049] In the present application, the face center is determined as follows. First, an arbitrary point Pr near the center of the striking face is selected in the vertical direction and the toe-heel direction. Next, a plane extending in the normal direction of the striking face at the point Pr and parallel to the toe-heel direction is determined. The intersection of this plane and the striking face is drawn, and a point Pa is determined. Next, a plane extending in the normal direction of the striking face at the point Pa and parallel to the vertical direction is determined. The intersection of this plane and the striking face is drawn, and a point Py is determined. Next, a plane extending in the normal direction of the striking face at the point Py and parallel to the toe-heel direction is determined. The intersection of this plane and the striking face is drawn, and a point Px is newly determined. Next, a plane extending in the normal direction of the striking face at the point Px and parallel to the vertical direction is determined. The intersection of this plane and the striking face is drawn, and a point Py is newly determined. This procedure is repeated, and Px and Py are sequentially determined. In the repetition of this procedure, when the distance between the new point Py and the immediately preceding point Py becomes 0.5 mm or less, the new position Py (the last position Py) is the face center.

[0050] In the present application, the longitudinal section is a section based on a plane perpendicular to the toe-heel direction. The longitudinal section is parallel to the loft-sole direction. The longitudinal section is perpendicular to the landing plane HP. The section line in the longitudinal section is also referred to as a longitudinal section line. The longitudinal section can be set at each position in the toe-heel direction.

[0051] The radius of curvature of the curved surface is determined in the longitudinal section. That is, the radius of curvature of the curved surface is determined in the longitudinal section line. The longitudinal section exists at each position in the toe-heel direction. The radius of curvature is determined at each of these longitudinal sections.

[0052] This radius of curvature is determined at each point on the longitudinal section line. In the determination of this radius of curvature, a measurement point is determined, and three points, one at the measurement point and the other two points spaced 0.5 mm on either side of the measurement point. The radius of the circle passing through these three points is defined as the radius of curvature of the measurement point. This 0.5 mm is the distance along the path of the section line. 0.5 mm is sufficiently small in evaluating the radius of curvature of the measurement point. Also, by setting two points 0.5 mm away 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.

[0053] Thus, the radius of curvature is determined for each point. In the present application, the meaning of the provision that the radius of curvature in a certain region is X mm or more and Y mm or less is that the radius of curvature is X mm or more and Y mm or less at all points belonging to the region.

[0054] In the present application, in the longitudinal section, a point on the inner surface of the head and a point on the outer surface of the head are corresponding to each other. A point A on the outer surface of the head has a normal line. When the intersection of this normal line and the inner surface of the head is a point B, the point A and the point B correspond to each other. In this case, it can be said that the point A corresponds to the point B, or it can be said that the point B corresponds to the point A.

[0055] Figure 1 is a general view of the golf club 2 including the head 4 of one embodiment of the present application. Figure 2 (a) is a front view of the head 4, Figure 2 (b) is a cross-sectional view along Figure 2 the E1 line of (a). In Figure 2 (b), only the cross-sectional line of the outer surface of the head 4 is shown. Figure 3 is a plan view of the head 4 as viewed from the top side of the head. Figure 4 is a bottom view of the head 4 as viewed from the bottom side of the head. Figure 5 is a cross-sectional view along Figure 2 the A-A line of (a). Figure 5 is a longitudinal cross-sectional view through the face center Fc. Figure 6 is an exploded perspective view of the head 4.

[0056] As shown in Figure 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 portion of the shaft 6. The grip 8 is attached to the butt end portion of the shaft 6.

[0057] The golf club 2 is a driver (a wood type golf club). Preferably, the golf club 2 is a wood type golf club or a hybrid type golf club.

[0058] The shaft 6 is a tubular body. The shaft 6 has a hollow structure. The shaft 6 is made of carbon fiber reinforced resin. From the viewpoint of weight reduction, carbon fiber reinforced resin is preferable as the material of the shaft 6. The shaft 6 is so-called carbon shaft. It is preferable that the shaft 6 is made by hardening a prepreg sheet. In this prepreg sheet, fibers are actually oriented in one direction. This prepreg treatment in which fibers are actually oriented in one direction is also called UD prepreg treatment. "UD" is an abbreviation of uniderection. A prepreg treatment other than UD prepreg treatment can also be used. For example, fibers included in the prepreg sheet can be woven. The shaft 6 can include a metal wire. The material of the shaft 6 is not limited, and for example, metal can also be used.

[0059] The grip 8 is a portion that a golfer holds during a swing. Rubber composition and resin composition are exemplified as the material of the grip 8. The rubber composition of the grip 8 can include a bubble.

[0060] As shown in Figure 5 The head 4 has a hollow structure as well. In the present embodiment, the head 4 is a wood type. The head 4 can be a hybrid type. The head 4 can be an iron type. The head 4 can be a putter type. It is preferable that the head 4 is a wood type or a hybrid type, and further preferable that the head 4 is a wood type. Metal and fiber reinforced plastic are exemplified as the preferable material of the head 4. As this metal, titanium alloy, pure titanium, stainless steel, martensitic steel, and wrought iron are exemplified. As the fiber reinforced plastic, carbon fiber reinforced plastic is exemplified. The head 4 can be a composite head having a metal portion and a fiber reinforced plastic portion.

[0061] As shown in Figure 2 (a) and Figure 4 The head 4 has a face portion 10, a crown portion 12, a sole portion 14, and a hosel portion 16 as shown in

[0062] The outer edge of the striking face 10a can be defined as follows. As Figure 2 (a) and Figure 2 (b) show, there are respective cross sections E1, E2, E3... including a straight line N1 connecting the center of gravity CG of the head 4 and the sweet spot SS. When the head 4 is viewed from the front Figure 2 (a), the straight line N1 is a point. In these respective cross sections E1 and the like, the radius of curvature r of the cross section line of the outer surface of the head first becomes 200 mm at a position Fe from the sweet spot SS side to the outside of the striking face 10a. This position Fe is defined as the outer edge of the striking face 10a. In addition, the sweet spot SS refers to the foot of the perpendicular from the center of gravity CG of the head 4 to the striking face 10a.

[0063] like Figure 5 As shown, the clubface 10 has an outer surface 10a and an inner surface 10b. The outer surface 10a is the striking face. The inner surface 10b faces the internal space (hollow portion) of the clubhead 4. The crown 12 has an outer top surface 12a and an inner top surface 12b. The inner top surface 12b faces the internal space (hollow portion) of the clubhead 4. The sole 14 has an outer bottom surface 14a and an inner bottom surface 14b. The inner bottom surface 14b faces the internal space (hollow portion) of the clubhead 4.

[0064] Furthermore, although a scribing (groove) is provided on the outer surface 10a of the rod, the description of this scribing is omitted in the various figures of this application.

[0065] The hollow clubhead 4 has a wall thickness. The wall thickness is the thickness between the inner surface and the outer surface of the clubhead 4. For example, the wall thickness of the face 10 is the thickness between the striking face 10a and the inner surface 10b of the striking face. Similarly, the wall thickness of the sole 14 is the thickness between the outer surface 14a and the inner surface 14b of the sole. The wall thickness is measured along the normal to the outer surface of the clubhead. The orientation of this normal varies depending on its position on the outer surface of the clubhead.

[0066] like Figure 3 As clearly shown, the crown 12 has a top protrusion 20 on the outer surface 12a of the top. The top protrusion 20 is hollow. That is, the top protrusion 20 forms a bulge on the outer surface 12a of the top and a recess in the inner surface of the top. The top protrusion 20 has a contour line CL20, a top surface 22, and sidewalls 24. In the top view of the clubhead 4 ( Figure 3 In the club face, the top protrusion 20 is approximately quadrilateral (approximately trapezoidal). The top protrusion 20 is located on the side closer to the clubhead heel than the center Fc of the clubface.

[0067] The outer surface 10a of the clubface is a three-dimensional curved surface that convexes outwards from the clubhead 4. The outer surface 10a of the clubface has a raised portion and an arc-shaped portion.

[0068] From the perspective of the constituent components, the clubhead 4 has a body component b1 and a face component f1. The body component b1 has a face opening b10. The face component f1 is disposed in the face opening b10. The face component f1 has an integral striking face 10a. The face component f1 closes the face opening b10. The face component f1 is welded to the face opening b10. The face component f1 has a portion of a crown 12. The face component f1 has a portion of a sole 14. The body component b1 has a portion of a crown 12. The body component b1 has a portion of a sole 14. The body component b1 has an integral neck 16.

[0069] Figure 3 and Figure 4The boundary line k1 between the face member f1 and the body member b1 in the outer surface of the head is indicated by a double-dot chain line.

[0070] The material of the body member b1 is not limited, and examples of the material include metal and fiber-reinforced plastic. As the metal, one or more selected from pure titanium, titanium alloy, stainless steel, martensitic steel, aluminum alloy, magnesium alloy, and tungsten-nickel alloy is exemplified. As the fiber-reinforced plastic, carbon fiber-reinforced plastic is exemplified. The body member b1 can be integrally formed as a whole. The body member b1 can be formed by joining a plurality of members. For example, the body member b1 can be formed by joining a member made of metal and a member made of carbon fiber-reinforced plastic. In the present embodiment, the body member b1 is formed as a whole by metal. The method of manufacturing the body member b1 is not limited. In the present embodiment, the body member b1 is manufactured by casting (lost-wax precision casting).

[0071] The material of the face member f1 is not limited, and is preferably metal. 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, as a preferable material of the face member f1, titanium alloy and martensitic steel are given. The manufacturing method of the face member f1 is not limited. From the viewpoint of strength, the face member f1 can be manufactured by press working a plate material. As this plate material, a rolled material can be used. The rolled material has few defects and excellent strength. Furthermore, the rolled material has high accuracy in thickness. By using the rolled material, the accuracy in thickness of the face 10 is improved. The face member f1 can also be manufactured by forging. The face member f1 can also be manufactured by casting. As described later, the length of the peripheral portion of the face member f1 of the present embodiment is small. For this reason, the face member f1 can be easily shaped by press working or forging. In the present embodiment, the face member f1 is manufactured by press working a rolled material. More specifically, the manufacturing process of the face member f1 can include a first process of processing the wall thickness of a plate material (rolled material) by CNC processing, a second process of press working the plate material after the first process, and a third process of trimming the peripheral portion from the material after the second process by CNC processing. In the second process, the curved surface (raised portion, arc-shaped portion) of the face is imparted, and a curved peripheral portion is formed. However, in the case where the peripheral portion is short, as in the peripheral portion 32 of the face member f1, bending processing is difficult, and sometimes the peripheral portion cannot be completely shaped by press working alone. In this case, it is preferable to implement the third process of adjusting the peripheral portion after the press working process. As the adjustment of this third process, adjustment of the length of the peripheral portion, and / or adjustment of the outer surface shape of the peripheral portion can be given. Laser cutting can be used for adjusting the length of the peripheral portion. CNC processing can be used for adjusting the outer surface shape of the peripheral portion. In the case where the outer surface shape of the peripheral portion is adjusted in the third process, the wall thickness can be set in the first process taking into account the amount of cutting of the outer surface in the third process. Furthermore, CNC is an abbreviation of Computerized Numerical Control.

[0072] Figure 7 is an enlarged view of the vicinity of the face 10 in Figure 5 Figure 8 is an enlarged view of the inside of the circle A of Figure 5 As described above, the club head 4 has a face member f1. The face member f1 is integrally formed as a whole. The face member f1 is welded to the body member b1. Figure 7 and Figure 8 In the single-dot chain line in the face member f1 and the body member b1, the boundary surface k2 of the face member f1 and the front end surface of the body member b1 is shown. The boundary surface k2 is the interface of the rear end surface of the face member f1 and the front end surface of the body member b1. In the longitudinal cross section, the boundary surface k2 constitutes the cross-sectional boundary line k3.​

[0073] Figure 9 is Figure 8 an enlarged view of the circle B. The cross-sectional boundary line k3 has a point Pl on the hosel inner surface side, and a point P2 on the hosel outer surface. The point Pl is covered with the weld bead wb. The cross-sectional boundary line k3 is a line segment connecting the point Pl and the point P2. The above-mentioned boundary line kl is a set of the point P2.

[0074] The face member fl has a face portion 10 constituting the striking face 10a, and a peripheral edge portion 32 extending from a peripheral edge of the face portion 10 toward the hosel heel side. As shown in Figure 6 , the peripheral edge portion 32 is provided over the entire periphery of the face member fl except for the vicinity of the hosel neck portion 16. However, as shown in Figure 6 and Figure 7 , the length of the peripheral edge portion 32 is short. The peripheral edge portion 32 includes a sole side peripheral edge portion 34, and a toe side peripheral edge portion 36. The sole side peripheral edge portion 34 extends from a lower edge of the face portion 10 toward the hosel heel side. The toe side peripheral edge portion 36 extends from an upper edge of the face portion 10 toward the hosel heel side. A rear end surface of the face member fl is a rear end surface of the peripheral edge portion 32.

[0075] The weld bead wb is formed at the welded portion. The weld bead wb is formed at a boundary position between the peripheral edge portion 32 and the body member bl. The weld bead wb is formed on the inner surface of the hosel 4. The weld bead wb is raised on the inner surface of the hosel. In the cross-sectional view of the present application, the weld bead wb is schematically shown as a semicircle.

[0076] Further, the kind of welding is not limited, and laser welding, arc welding, gas welding, and resistance welding are exemplified. A filler material (a welding rod or the like) can or can not be used. In the present embodiment, laser welding is employed. The weld bead wb can be formed of only a base material, can be formed of only a filler material, or can be formed of a base material and a filler material. In the present embodiment, the filler material is not used, and the weld bead wb is formed of the base material (the body member bl and the face member fl) which is melted and then solidified.

[0077] As shown in Figure 7 , in the longitudinal cross section, the cross-sectional line of the striking face 10a has a midpoint Pa. The midpoint Pa is a midpoint of the cross-sectional line extending between the outer edge Fe on the sole side and the outer edge Fe on the toe side. The midpoint Pa is determined for each longitudinal cross section. The midpoint Pa has a tangent line Ta. The tangent line Ta is a tangent line at the midpoint Pa of the cross-sectional line of the striking face 10a. The face inner surface 10b has a point Pb. The point Pb is a point corresponding to the point Pa. That is, the point Pb is an intersection point of the normal line Dl at the midpoint Pa and the face inner surface 10b. A straight line Tb passing through the point Pb and parallel to the tangent line Ta is determined.

[0078] The peripheral portion 32 has a rearward extension portion 38 that protrudes toward the rear of the head side more than the face portion 10. The rearward extension portion 38 is a portion that extends toward the rear of the head side more than the straight line Tb. The rearward extension portion 38 includes a sole side rearward extension portion 40 and a top side rearward extension portion 42.

[0079] As shown in Figure 7 and Figure 9 , the peripheral portion 32 has a length LI. The length LI of the peripheral portion 32 is a length from the outer edge Fe to the outer surface boundary point P2. This length LI is measured in the face normal direction. The face normal direction is the direction of the normal line Dl at the midpoint Pa (refer to Figure 7 ). Thus, the face normal direction is perpendicular to the tangent line Ta, and also perpendicular to the straight line Tb. In Figure 9 , the length LI l of the sole side peripheral portion 34 is indicated. In Figure 7 , the length LI2 of the top side peripheral portion 36 is indicated. The length LI l and the length LI2 are examples of the length LI.

[0080] As shown in Figure 7 , the sole side peripheral portion 34 has a face-rear of the head direction length L2. The length L2 is a length from the outer edge Fe of the sole side to the outer surface boundary point P2 of the sole side. The top side peripheral portion 36 has a face-rear of the head direction length L3. The length L3 is a length from the outer edge Fe of the top side to the outer surface boundary point P2 of the top side. The length L3 is greater than the length L2. In the present application, the length LI of the peripheral portion 32 is not defined as the face-rear of the head direction length L2, L3, but is defined as the length in the face normal direction (refer to the double-headed arrow LI in Figure 7 , Figure 9 ).

[0081] Figure 9 The length of the rearward extension portion 38 is indicated by the double-headed arrow L4 in Figure 9 . The rearward extension portion 38 has a length L4. The length L4 is a length from the straight line Tb to the end point P2. This length L4 is measured in the face normal direction. In Figure 7 , the length L41 of the sole side rearward extension portion 40 is indicated. In , the length L42 of the top side rearward extension portion 42 is indicated. The length L41 and the length L42 are examples of the length L4.

[0082] When the face member fl and the body member bl are welded, the boundary surface k2 can become unclear. Although not shown, by welding, a weld portion that solidifies once melted is formed in the vicinity of the boundary surface k2. Although not shown, the shape of a longitudinal section of this weld portion is not fixed, and has a width.

[0083] Through this weld, the boundary surface k2 may become unclear. If the boundary surface k2 is unclear, the two endpoints P1 and P2 of the section boundary line k3 may also become unclear. In this case, points P1 and P2 can be determined as follows: Figure 9 As shown, in the longitudinal section, the endpoint P3 on the bar face side of weld wb and the endpoint P5 on the body side of weld wb are determined. Furthermore, the midpoint of the line segment connecting point P3 and point P5 is determined. This midpoint is defined as point P1. On the other hand, point P2 can be defined as the midpoint of the section line of the weld portion exposed on the outer surface of the bar head 4. Point P2 can be defined as the midpoint of the section line that is a curve. The line segment connecting these points P1 and P2 can be used as the section boundary line k3 in the longitudinal section. By determining the section boundary line k3, the dimensions of the bar face component f1 in the post-weld state can be determined. Furthermore, welds can typically be formed on the outer surface of the bar head 4, but welds on this outer surface are removed by grinding.

[0084] Point P1 is the center point of weld wb, also known as the weld center point. Point P2 is also known as the outer surface boundary point.

[0085] In the longitudinal section, points P4 and P6 are determined on the outer surface of the rod head 4 (refer to...). Figure 9 Point P4 corresponds to endpoint P3 on the bar side of weld wb. Point P6 corresponds to endpoint P5 on the body side of weld wb.

[0086] In the longitudinal section, point P7 is determined on the inner surface of the clubhead 4 (refer to...). Figure 8 Point P7 is the point corresponding to the outer edge Fe of the striking face 10a. The straight line connecting the outer edge Pe and point P7 forms the outer edge of the striking face 10.

[0087] In the longitudinal section, point P9 is determined on the inner surface of the clubhead 4 (refer to...). Figure 8 Point P9 is a point 6 mm away from the weld center point P1 towards the main component b1. This 6 mm is the distance along the section line. That is, 6 mm is the length of the section line from point P1 to point P9. In the longitudinal section, point P8 is determined on the outer surface of the rod head 4. Point P8 is the point corresponding to point P9.

[0088] Figure 8 Only the area near the bottom periphery 34 is shown, but points P1 to P9 are also defined near the top periphery 36.

[0089] like Figure 8As shown, the clubhead 4 has a face-side weld proximity portion 50 and a body-side weld proximity portion 52. The face-side weld proximity portion 50 is the weld proximity portion of the face component f1. The face-side weld proximity portion 50 extends from the outer edge Fe of the striking face 10a to the weld wb. The body-side weld proximity portion 52 is the weld proximity portion of the body component b1. The body-side weld proximity portion 52 extends from a point 6 mm away from the weld center point P1 towards the body side to the weld wb. On the sole side, the outer surface of the body-side weld proximity portion 52 forms part of the sole outer surface 14a.

[0090] The inner surface 50b of the near-weld portion 50 on the face side is the region from endpoint P3 to point P7. The outer surface 50a of the near-weld portion 50 on the face side is the region from point P4 to the outer edge Fe. The inner surface 52b of the near-weld portion 52 on the body side is the region from endpoint P5 to point P9. The outer surface 52a of the near-weld portion 52 on the body side is the region from point P6 to point P8. The outer surface of the near-weld portion 52 on the body side includes the outer surface boundary point P2.

[0091] A thick-walled joint 54 is formed between the near-weld portion 50 on the bar face side and the near-weld portion 52 on the body side. The outer surface of the thick-walled joint 54 is the region from point P4 to point P6. The inner surface of the thick-walled joint 54 is the surface of the weld wb. The thick-walled joint 54 connects the near-weld portion 50 on the bar face side and the near-weld portion 52 on the body side.

[0092] The same construction is also formed on the top side of the rod. For example... Figure 7 As shown, in the longitudinal section, the club head 4 has a face-side weld proximity portion 50 and a body-side weld proximity portion 52 on its top side. The outer surface of the body-side weld proximity portion 52 on the top side forms part of the club top outer surface 12a. A thick-walled joint portion 54 is formed between the face-side weld proximity portion 50 and the body-side weld proximity portion 52.

[0093] like Figure 9 As shown, the wall thickness t1 of the portion 50 near the weld on the bar face side decreases as it moves away from the bar face 10. The wall thickness t1 decreases continuously as it moves away from the bar face 10. Alternatively, the wall thickness t1 may decrease in stages as it moves away from the bar face 10.

[0094] like Figure 9 As shown, the wall thickness t2 of the portion 52 near the main body weld thins as it moves away from the rod face 10. The wall thickness t2 thins continuously as it moves away from the rod face 10. Alternatively, the wall thickness t2 may thin in stages as it moves away from the rod face 10.

[0095] Furthermore, regarding wall thickness, the term "phased" means that it can be used even without excluding stepped shapes. That is, the concept of "phased" includes structures where parts with fixed wall thickness are connected to parts with continuously varying wall thickness without any height difference.

[0096] The wall thickness t1 includes the wall thickness t11 at the end point P3 on the bar-side of weld wb. Wall thickness t11 is the length of the line segment connecting point P3 and point P4. Wall thickness t11 is the wall thickness at the end point P3 on the bar-side of weld wb. Wall thickness t11 is the minimum value of wall thickness t1.

[0097] The wall thickness t2 includes the wall thickness t21 at the endpoint P5 on the main body side of weld wb. Wall thickness t21 is the length of the line segment connecting point P5 and point P6. Wall thickness t21 is the wall thickness at the endpoint P5 on the main body side of weld wb. Wall thickness t21 is the maximum value of wall thickness t2.

[0098] The wall thickness t11 at the end point P3 on the rod side of weld wb is greater than the wall thickness t21 at the end point P5 on the main body side of weld wb.

[0099] The inner surface of the near-weld portion 50 on the face side forms a smooth, continuous curved surface. The inner surface of the near-weld portion 50 on the face side has a radius of curvature within a specified range. The inner surface of the near-weld portion 52 on the body side forms a smooth, continuous curved surface. The inner surface of the near-weld portion 52 on the body side has a radius of curvature within a specified range. The outer surface of the near-weld portion 50 on the face side is continuous with the outer surface of the near-weld portion 52 on the body side through the outer surface of the thick-walled joint 54. These outer surfaces are smoothly continuous with a radius of curvature within a specified range.

[0100] like Figure 7 As shown, the bar face 10 has a maximum thickness tmax and a minimum thickness tmin. The maximum thickness tmax is the maximum value of the wall thickness of the bar face 10. The minimum thickness tmin is the minimum value of the wall thickness of the bar face 10. Although in Figure 7 The maximum thickness tmax and minimum thickness tmin are shown, but in reality, the maximum thickness tmax and minimum thickness tmin may not exist on the longitudinal section passing through the center Fc of the bar face.

[0101] The 4th clubhead serves the following functions.

[0102] The face component f1 is a cup-shaped face with a peripheral portion 32. Therefore, there is no welded portion on the face portion 10. At a welded portion, the wall thickness increases and rigidity is improved due to the presence of the weld. Thus, if a welded portion were present on the face portion 10, it could potentially suppress the deflection of the face portion 10. Because there is no welded portion on the face portion 10, the face portion 10 as a whole is prone to deflection.

[0103] At the head 4, the length LI of the peripheral portion 32 is short, 6 mm or less. For this reason, the welded portion of the face member fl and the body member bl is disposed near the boundary of the face portion 10 and the crown portion 12. Also, the welded portion of the face member fl and the body member bl is disposed near the boundary of the face portion 10 and the sole portion 14. A weld bead that protrudes from the inner surface of the head is formed at this welded portion. With this structure, the rigidity of the vicinity of the boundary portion (boundary portion of the face portion and the crown portion or the sole portion) of the face portion 10 is improved. For this reason, the boundary of the face portion 10 and the crown portion 12, and the boundary of the face member fl and the sole portion 14 become difficult to bend. As a result, the starting point of the bending at the time of hitting a ball can be moved toward the body side (the back side of the head).

[0104] The wall thickness tl 1 at the end point P3 of the face side of the weld bead wb is greater than the wall thickness t21 at the end point P5 of the body side of the weld bead wb. For this reason, the rigidity near the face portion 10 side becomes high, and the starting point of the bending at the time of hitting a ball can be moved toward the body side.

[0105] By moving the starting point of the bending toward the body side, the flexural wave at the time of hitting a ball reaches the body member bl that is separated from the face portion 10. For this reason, by the deformation of the body member bl (the crown portion 12, the sole portion 14), the displacement amount of the entire face portion 10 increases compared to the case where the boundary portion of the face portion 10 is bent. As a result, the rebound performance is improved. This effect is also called a body flexing effect.

[0106] From the viewpoint of the body flexing effect, the length LI of the peripheral portion 32 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and even 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 becomes easy to bend. From this viewpoint, the length LI is preferably 2.5 mm or more, more preferably 2.7 mm or more, and even more preferably 3.0 mm or more.

[0107] From the viewpoint of the body flexing effect from the sole side, the length LI 1 of the sole side peripheral portion 34 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and even 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 becomes easy to bend. From this viewpoint, the length LI 1 is preferably 2.5 mm or more, more preferably 2.7 mm or more, and even more preferably 3.0 mm or more.

[0108] From the viewpoint of the body flexing effect on the rod top side, the length L12 of the rod top side peripheral portion 36 is preferably 6.0 mm or less, more preferably 5.5 mm or less, and even more preferably 5.0 mm or less. If the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 is inhibited, and the boundary portion of the rod face portion 10 becomes easy to bend. From this viewpoint, the length L12 is preferably 2.5 mm or more, more preferably 2.7 mm or more, and even more preferably 3.0 mm or more.

[0109] If the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 is inhibited, and the boundary portion of the rod face portion 10 becomes easy to bend. 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.

[0110] On the rod bottom side, if the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 on the rod bottom side is inhibited. From this viewpoint, the length L11 of the rod bottom side peripheral portion 34 is preferably greater than the minimum thickness tmin of the rod face portion 10, and more preferably greater than the maximum thickness tmax.

[0111] On the rod top side, if the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 on the rod top side is inhibited. From this viewpoint, the length L12 of the rod top side peripheral portion 36 is preferably greater than the minimum thickness tmin, and more preferably greater than the maximum thickness tmax.

[0112] From the viewpoint of the body flexing 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 even more preferably 2.8 mm or less. If the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 is inhibited, and the boundary portion of the rod face portion 10 becomes easy to bend. From this viewpoint, the length L4 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more.

[0113] From the viewpoint of the body flexing effect on the rod bottom side, the length L41 of the rod bottom side rear extension portion 40 is preferably 3.3 mm or less, more preferably 3.0 mm or less, and even more preferably 2.8 mm or less. If the weld bead wb is too close to the rod face portion 10, the deformation of the rod face portion 10 is inhibited, and the boundary portion of the rod face portion 10 becomes easy to bend. From this viewpoint, the length L41 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more.

[0114] From the viewpoint of the body flexing effect on the top side of the shaft, the length L42 of the rear extension 42 on the top side of the shaft is preferably 3.3 mm or less, more preferably 3.0 mm or less, and even 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 inhibited, and the boundary portion of the face portion 10 becomes easy to bend. From this viewpoint, the length L42 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more.

[0115] From the viewpoint of the body flexing 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 inhibited, and the boundary portion of the face portion 10 becomes easy to bend. From this viewpoint, the presence of the rear extension 38 is preferable.

[0116] From the viewpoint of the body flexing effect on the bottom side of the shaft, the length L41 of the rear extension 40 on the bottom side of the shaft 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 inhibited, and the boundary portion of the face portion 10 becomes easy to bend. From this viewpoint, the presence of the rear extension 40 on the bottom side of the shaft is preferable.

[0117] From the viewpoint of the body flexing effect on the top side of the shaft, the length L42 of the rear extension 42 on the top side of the shaft is preferably 3.3 mm or less, more preferably 3.0 mm or less, and even 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 inhibited, and the boundary portion of the face portion 10 becomes easy to bend. From this viewpoint, the length L42 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more.

[0118] L4 / L1 is the ratio of the length L4 of the rear extension 38 to the length LI of the peripheral portion 32. From the viewpoint of the body flexing effect, L4 / L1 is preferably 0.55 or less, more preferably 0.5 or less, and even 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 inhibited, and the boundary portion of the face portion 10 becomes easy to bend. From this viewpoint, L4 / L1 is preferably 0.08 or more, more preferably 0.1 or more, and even more preferably 0.15 or more.

[0119] L41 / L11 is the ratio of the length L41 of the rear extension 40 on the bottom side of the shaft to the length L11 of the peripheral portion 34 on the bottom side of the shaft. From the viewpoint of the main body deflection effect on the bottom side of the shaft, an L41 / L11 of 0.55 or less is satisfactory, 0.5 or less is better, and 0.45 or less is even better. If the weld wb is too close to the shaft face 10, it will inhibit the deformation of the shaft face 10, making the boundary of the shaft face 10 easier to bend. From this viewpoint, an L41 / L11 of 0.08 or more is satisfactory, 0.1 or more is better, and 0.15 or more is even better.

[0120] L42 / L12 is the ratio of the length L42 of the rearward extension 42 on the top side of the rod to the length L12 of the peripheral portion 36 on the top side of the rod. From the viewpoint of the main body deflection effect on the top side of the rod, an L42 / L12 of 0.55 or less is satisfactory, 0.5 or less is better, and 0.45 or less is even better. If the weld wb is too close to the face 10 of the rod, it will inhibit the deformation of the face 10 of the rod, making the boundary of the face 10 of the rod easy to bend. From this viewpoint, an L42 / L12 of 0.08 or more is satisfactory, 0.1 or more is better, and 0.15 or more is even better.

[0121] The wall thickness t1 of the portion 50 near the weld on the shaft face becomes thinner as it moves away from the shaft face 10 (see reference). Figure 9 Therefore, it is possible to more effectively move the starting point of the bend at impact towards the back of the clubhead. A continuous or phased thinning of the wall thickness t1 as it leaves the clubface 10 is satisfactory; a continuous thinning as it leaves the clubface 10 is preferable.

[0122] From the viewpoint of suppressing bending of the near-weld portion 50 on the clubface side and shifting the starting point of bending towards the back of the clubhead during impact, a wall thickness t1 of 1.2 mm or more is satisfactory, 1.3 mm or more is better, and 1.4 mm or more is even more desirable. From the viewpoint of ensuring proper wall thickness distribution from the clubface 10 to the main body component b1 and shifting the starting point of bending towards the back of the clubhead, a wall thickness t1 of 2.0 mm or less is satisfactory, 1.8 mm or less is better, and 1.6 mm or less is even more desirable. A wall thickness t1 less than the maximum thickness tmax of the clubface 10 is satisfactory, and less than the minimum thickness tmin of the clubface 10 is even more desirable.

[0123] The wall thickness t2 of the portion 52 near the main body weld thins as it moves away from the rod face 10 (see reference). Figure 9 Therefore, the starting point of the bend at impact can be moved more effectively towards the body side (the back side of the clubhead). A continuous or phased thinning of the wall thickness t2 as it leaves the clubface 10 is satisfactory; a continuous thinning as it leaves the clubface 10 is preferable.

[0124] From the viewpoint of suppressing the bending of the main body side weld vicinity portion 52 and moving the start point of the bending at the time of hitting to the hosel back portion side, the wall thickness t2 is preferably 0.8 mm or more, more preferably 0.9 mm or more, and even more preferably 1.0 mm or more. From the viewpoint of making the wall thickness distribution of the face portion 10 to the main body portion bl appropriate and moving the start point of the bending to the hosel back portion side, the wall thickness t2 is preferably 1.8 mm or less, more preferably 1.6 mm or less, and even more preferably 1.4 mm or less. The wall 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 wall thickness t2 is preferably smaller than the wall thickness tl l at the end point of the face side of the weld wb.

[0125] By increasing the radius of curvature of the inner surface 50b of the face side weld vicinity portion 50, the bending deformation at the face side weld vicinity portion 50 is suppressed. For this reason, the start point of the bending at the time of hitting can be more effectively moved to the main body side (hosel back portion side) (see Figure 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 even more preferably 8 mm or more. If this radius of curvature is too large, the longitudinal width from the outer edge Fe of the striking face 10a to the bottom portion 14 becomes too large, and the longitudinal 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 even more preferably 29 mm or less.

[0126] By increasing the radius of curvature of the outer surface 50a of the face side weld vicinity portion 50, the bending deformation at the face side weld vicinity portion 50 is suppressed. For this reason, the start point of the bending at the time of hitting can be more effectively moved to the main body side (hosel back portion side) (see Figure 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 even more preferably 9 mm or more. If this radius of curvature is too large, the longitudinal width from the outer edge Fe of the striking face 10a to the bottom portion 14 becomes too large, and the longitudinal 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 even more preferably 30 mm or less.

[0127] By increasing the radius of curvature of the inner surface 52b of the main body side weld vicinity portion 52, the start point of the bending at the time of hitting can be more effectively moved to the main body side (hosel back portion side) (see Figure 8From this perspective, a radius of curvature of 7 mm or more for the inner surface 52b is satisfactory, 8 mm or more is better, and 9 mm or more is even better. If this radius of curvature is too large, the continuity of the curved surface shape from the welded area 50 on the bar face to the bottom 14 may be compromised. From this perspective, a radius of curvature of 34 mm or less for the inner surface 52b is satisfactory, 32 mm or less is better, and 29 mm or less is even better.

[0128] By increasing the radius of curvature of the outer surface 52a of the part near the main body weld 52, the starting point of the bend during impact can be moved more effectively towards the main body side (the back side of the clubhead) (see reference). Figure 8 From this perspective, a radius of curvature of 7 mm or more for the outer surface 52a is satisfactory, 8 mm or more is better, and 9 mm or more is even better. If this radius of curvature is too large, the continuity of the curved surface shape from the welded area 50 on the bar face to the bottom 14 may be compromised. From this perspective, a radius of curvature of 35 mm or less for the outer surface 52a is satisfactory, 33 mm or less is better, and 30 mm or less is even better.

[0129] As described above, in the reference state, the clubhead 4 is placed on the ground plane HP. In the longitudinal section passing through the center Fc of the clubface, the outer surface boundary point P2 does not contact the ground plane HP (see reference). Figure 7 In the longitudinal section passing through the center Fc of the rod face, the outer surface boundary point P2 is suspended from the ground plane HP. Figure 7 The distance indicated by the double arrow L5 is the distance between the ground plane HP and the outer surface boundary point P2 in the longitudinal section passing through the center Fc of the bar face. This distance is measured in a direction perpendicular to the ground plane HP. From the viewpoint of the main body deflection effect, a distance L5 of 1.2 mm or more is satisfactory, 1.4 mm or more is better, and 1.6 mm or more is even better. If the weld wb is too close to the bar face 10, it will inhibit the deformation of the bar face 10, making the boundary of the bar face 10 easier to bend. From this viewpoint, a distance L5 of 5.0 mm or less is satisfactory, 4.5 mm or less is better, and 4.0 mm or less is even better.

[0130] As described above, the aforementioned longitudinal sections are set at various positions in the clubhead toe-heel direction. By extending the aforementioned shape in the clubhead toe-heel direction, the overall flexural effect is improved. All of the above structures are satisfactorily satisfied in the longitudinal section passing through the clubface center Fc; better satisfied in all longitudinal sections from 10mm to the clubhead toe side of the clubface center Fc to 10mm to the clubhead toe side; even better satisfied in all longitudinal sections from 15mm to the clubhead toe side of the clubface center Fc to 15mm to the clubhead toe side; and most preferably satisfied in all longitudinal sections from 20mm to the clubhead toe side of the clubface center Fc to 20mm to the clubhead toe side.

[0131] From the viewpoint of transmitting the force added to the face portion 10 by the collision of the ball to the crown portion 12 to deform the crown portion 12, it is preferable that the angle between the face portion 10 and the crown portion 12 be close to a right angle. From the viewpoint of transmitting the force added to the face portion 10 by the collision of the ball to the sole portion 14 to deform the sole portion 14, it is preferable that the angle between the face portion 10 and the sole portion 14 be close to a right angle. From these viewpoints, it is good that the lie angle be small. It is satisfactory that the actual lie angle be 16 degrees or less, better 15 degrees or less, and much better 14 degrees or less. From the viewpoint of the proper launch angle, it is satisfactory that the actual lie angle be 7 degrees or more, better 7.5 degrees or more, and much better 8 degrees or more.

[0132] With respect to the above-described embodiments, the following supplementary notes are disclosed.

[0133] [Supplementary Note 1]

[0134] A golf club head having a head outer surface and a head inner surface, and being hollow, wherein:

[0135] a main body member having an opening; and

[0136] a face member having a striking face and closing the opening,

[0137] 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 heel side,

[0138] the peripheral portion of the face member is welded to the main body member,

[0139] a weld bead bulging on the head inner surface is formed at a boundary position between the peripheral portion and the main body member,

[0140] a wall thickness at an end point of the weld bead on the face side is greater than a wall thickness at an end point of the weld bead on the main body side,

[0141] a length of the peripheral portion is 6 mm or less.

[0142] [Supplementary Note 2]

[0143] The golf club head as recited in Supplementary Note 1, wherein the peripheral portion has a rearward extension portion protruding toward the heel side beyond the face portion.

[0144] [Supplementary Note 3]

[0145] The golf club head as recited in Supplementary Note 1 or 2, wherein a face side weld vicinity portion is between an outer edge of the face portion and the weld bead, and

[0146] When a portion near the main body side weld is defined as a portion from a point 6 mm apart from a center point of the weld toward the main body side to the weld,

[0147] The wall thickness of the hosel side weld near portion is thinned as it departs from the hosel portion,

[0148] The wall thickness of the main body side weld near portion is thinned as it departs from the hosel portion.

[0149] [Postamble 4]

[0150] The golf club head according to any one of the postambles 1 to 3, a radius of curvature of an inner surface of the hosel side weld near portion is 7 mm or more,

[0151] A radius of curvature of an outer surface of the hosel side weld near portion is 7 mm or more.

[0152] [Postamble 5]

[0153] The golf club head according to any one of the postambles 1 to 4, a length of the peripheral portion is greater than a minimum thickness of the hosel portion.

[0154] [Postamble 6]

[0155] The golf club head according to any one of the postambles 1 to 5, the peripheral portion is a sole side peripheral portion formed on a sole side of the hosel member.

Claims

1. A golf club head, said golf club head having an outer surface and an inner surface, and being hollow, characterized in that, have: A main body component with an opening; and A clubface component having a striking face that closes the opening. The clubface component has: a shaft face that constitutes the striking face and a peripheral portion extending from the outer edge of the shaft face toward the back of the clubhead. The peripheral portion of the rod face component is welded to the main body component. A weld seam that protrudes from the inner surface of the rod head is formed at the boundary between the peripheral portion and the main body component. The wall thickness at the end point on the rod side of the weld is greater than the wall thickness at the end point on the main body side of the weld. The length of the peripheral portion is less than 6 mm. When the area from the outer edge of the rod face to the weld is near the rod face side weld, and From the point 6mm away from the center of the weld towards the main body side, to the area near the weld on the main body side, The wall thickness near the weld on the rod face decreases as it moves away from the rod face. The wall thickness near the weld on the main body side decreases as it moves away from the rod face. The radius of curvature of the inner surface near the welding area on the rod face is 7 mm or more. The radius of curvature of the outer surface near the welding area on the rod face is 7 mm or more.

2. The golf club head as described in claim 1, characterized in that, The peripheral portion has a rearward extension that protrudes towards the back of the clubhead compared to the shaft face.

3. The golf club head as described in claim 1 or 2, characterized in that, The length of the peripheral portion is greater than the minimum thickness of the rod surface portion.

4. The golf club head as described in claim 1 or 2, characterized in that, The peripheral portion is the bottom peripheral portion formed on the bottom side of the shaft face component.

Images