Golf club head

Abstract

A hollow golf club head according to this invention includes a face portion, a crown portion, and a sole/side portion which includes a sole portion and a side portion. This golf club head includes a rib which extends from the toe side to the heel side in the sole portion, and a weight portion which is provided in the sole portion on the back side with respect to the rib, and increases the amplitude of vibration of the sole portion. The natural frequency of the first-order vibration mode of the sole portion is 2,500 Hz or more. A mass m (g) of the weight portion satisfies 1≦m<6. The rib has a quadrangular cross-sectional shape with a width b (mm) and a height h (mm), and 0.20≦b·h 3 /m 4 <8.00.

1 . A hollow golf club head including a face portion, a crown portion, and a sole/side portion which includes a sole portion and a side portion, the head comprising:
 a rib which extends from a toe side to a heel side in the sole portion; and   a weight portion which is provided in the sole portion on a back side with respect to said rib, and increases an amplitude of vibration of the sole portion,   wherein a natural frequency of a first-order vibration mode of the sole portion is not less than 2,500 Hz,   a mass m (g) of said weight portion satisfies 1≦m<6,   said rib has a quadrangular cross-sectional shape with a width b (mm) and a height h (mm), and   0.20≦b·h 3 /m 4 <8.00.   
     
     
         2 . The head according to  claim 1 , wherein
 the sole/side portion includes a thick region on a side of the face portion, a thin region, and a thick region on the back side in turn from the side of the face portion to the back side, and   said rib and said weight portion are disposed in the thin region.   
     
     
         3 . The head according to  claim 1 , wherein a head volume is not less than 400 cc.