To provide a golf club head excellent in hitting sound and flight distance performance. A head includes a face, a crown and a sole. The crown has an inner surface on which grid-form rib is provided. When a region on which the grid-form rib is provided is defined as a rib region, an additional rib is further provided on the rib region. The additional rib is positioned on a heel side relative to a face center. Preferably, the grid-form rib is formed by intersection of first ribs extending in a substantially toe-heel direction and second ribs extending in a substantially face-back direction. Preferably, the additional rib is sloped to be closer to a back side as approaching to the heel side.
1. A golf club head comprising:
a face;
a sole; and
a crown, wherein
grid-form rib is provided on an inner surface of the crown,
when a first region on which the grid-form rib is provided is defined as a rib region, a plurality of additional ribs are further provided on the rib region,
in each of the additional ribs, a center of gravity of the additional rib is positioned on a heel side relative to a face center,
the grid-form rib is formed by intersection of first ribs extending in a direction having an angle of with ±20° relative to a toe-heel direction in a plan view and second ribs extending in a direction having an angle ±20° relative to a face-back direction in the plan view,
the additional ribs are not the first ribs and not the second ribs, and
each of the additional ribs extends at an angle relative to an adjacent first rib and adjacent second rib.
2. The golf club head according to claim 1 , wherein
a plurality of rib-surrounding regions, each of which is surrounded by two first ribs and two second ribs, are formed, and
at least one of the additional ribs extends so as to divide each of the plurality of rib-surrounding regions through which it passes into two parts.
3. The golf club head according to claim 2 , wherein
an second region is further provided on the inner surface of the crown,
the second region is positioned on the face side of the rib region, and
an average thickness of the second region is greater than an average thickness of the rib-surrounding regions.
4. The golf club head according to claim 3 , wherein
one end of at least one of the additional ribs is connected to the second region.
5. The golf club head according to claim 3 , wherein
the grid-form rib and the additional ribs are not provided on the second region.
6. The golf club head according to claim 1 , wherein
at least one of the additional ribs is sloped to be closer to a back side as approaching to the heel side.
7. The golf club head according to claim 6 , wherein
when a slope angle of the additional rib relative to a face-back direction is defined as θa, the angle θa is equal to or greater than 30° and equal to or less than 70°.
8. The golf club head according to claim 1 , wherein
the entire additional ribs are positioned on the heel side relative to the face center as concerns all the additional ribs.
9. The golf club head according to claim 1 , wherein
an second region is further provided on the inner surface of the crown,
the second region is positioned on the face side of the rib region, and
the grid-form rib and the additional ribs are not provided on the second region.
10. The golf club head according to claim 9 , wherein
one end of at least one of the additional ribs is connected to the second region.
11. The golf club head according to claim 9 , wherein
a third region is further provided on the inner surface of the crown,
the third region surrounds the rib region and the second region, and
the grid-form rib and the additional ribs are not provided on the third region.