| 摘要 |
PROBLEM TO BE SOLVED: To provide a mold with vent holes for vulcanization-molding a pneumatic tire, with such advantages that even a complicated split mold can be easily machined and a vent spew trimming process need not be performed as an after-process and further, the discharging of air around the base part of a protrusion during vulcanization-molding is satisfactory, with the capability of forming a fine groove of high shape stability in a buttress area of a tire after vulcanization-molding. SOLUTION: This split mold is structured of a pair of a top and a bottom side mold 1 and 1 for forming the side part of an unvulcanized tire, a plurality of tread segments 2 forming the tread part of the unvulcanized tire and an annular protrusion 1A for molding an annular fine groove in the buttress area of a vulcanization-molded tire, formed near a contact face between the side mold 1 and the tread segment 2. In the mold, a plurality of vent holes VH1 transversely penetrating both wall faces of the annular protrusion 1A, are formed in the annular protrusion 1A. |
