Tire vulcanization mold and method for manufacturing tire
A tire vulcanization mold comprises a ring shaped tread mold which comprises a plurality of segments, each segment with a radially inner face and a pair of end faces each of which extends from a circumferential end of the inner face toward radially outwardly of the tire, the segments arranged in a circumferential direction of the tire to have a substantially continuous tread molding face by connecting inner faces one another, each inner face of segments comprising a circumferentially extending rib, a laterally extending rib, and blades for molding sipes, the blades including three dimensional blades which comprises a first blade with a thickness not more than 0.3 mm and a second blade with a thickness of from 0.4 to 0.6 mm arranged in one of the circumferentially end regions.
1. A tire vulcanization mold comprising
a ring shaped tread mold for molding a tread pattern of a tire to be molded, said ring shaped tread mold comprising a plurality of segments,
said each segment having a radially inner face and a pair of end faces each of which extends from a circumferential end of the inner face toward radially outwardly of the tire, said segments being arranged in a circumferential direction of the tire so as to have a substantially continuous tread molding face by connecting inner faces one another,
said each inner face of the segment comprising at least one circumferentially extending rib for molding a circumferential groove of the tread pattern, at least one laterally extending rib for molding a lateral groove of the tread pattern, and a plurality of blades for molding sipes of the tread pattern, wherein the blades are arranged in the tire circumferential direction to form a row of blades,
said each inner face of the segment consisting of a pair of segment inner face circumferentially end regions each having a circumferential length of 5% of a tread width of the tread pattern from each circumferential end of the inner face of the segment, and a segment inner face circumferentially middle region between the pair of segment inner face circumferentially end regions,
in the row of blades, said blades including a plurality of three dimensional blades which longitudinally extend in a zigzag manner, said three dimensional blades comprising a plurality of first blades arranged consecutively in the circumferential direction of the tire and each having a thickness in a range of from not more than 0.3 mm and at least one second blade having a thickness in a range of from 0.4 to 0.6 mm, and
the segment inner face circumferentially middle region being provided with only the plurality of first blades and the pair of segment inner face circumferentially end regions being provided with only the at least one second blade.
2. The tire vulcanization mold according to claim 1 , wherein
said three dimensional blades comprise a primary portion and a secondary portion disposed radially inwardly or outwardly of the primary portion,
the primary portion comprises a plurality of adjacent parallelogram elements which are connected in a first zigzag manner in the longitudinal direction of the blade,
the secondary portion comprises a plurality of adjacent parallelogram elements which are connected in a second zigzag manner in the longitudinal direction of the blade which differs from the first zigzag manner, and
a zigzag amplitude of the first zigzag manner is the same as a zigzag amplitude of the second zigzag manner.
3. The tire vulcanization mold according to claim 1 , wherein
said tread pattern has a designated install direction to a vehicle so as to have an outboard tread edge and an inboard tread edge,
said at least one circumferentially extending rib comprises an inboard circumferential rib arranged the nearest of the inboard tread edge and an outboard circumferential rib arranged the nearest of the outboard tread edge,
said inboard circumferential rib and the outboard circumferential rib are non-symmetrically arranged with respect to a tire equator,
said substantially continuous tread molding face includes an inboard shoulder region which is an axially outside region than the inboard circumferential rib and an outboard shoulder region which is an axially outside region than the outboard circumferential rib,
said each circumferentially end region of the inner face of the segment traverses between the laterally extending rib and the blade in the inboard shoulder region,
said each circumferentially end of the inner face of the segment traverses between the blades in the outboard shoulder region, and
the number of blades in the inboard shoulder region is larger than the number of blades in the outboard shoulder region.
4. A method for manufacturing a tire comprising a step of vulcanizing of a tire using the tire vulcanization mold according to claim 1 .