To suppress a tread from being unevenly worn to prevent the tread from being broken and a side blade from being damaged during mold opening.SOLUTION: In a pneumatic tire, a tread is provided with a plurality of narrow grooves 50 formed with an interval in a tire circumferential direction and division traces provided at a division position of a sector. The narrow grooves comprise sipes 53A, 53C and the other extending in a tire axial direction and chamfers 54A, 54C and the other expanding widths of ends of openings toward a grounding surface 8a of the sipes. When ranges within a first angle θ1 from the division traces towards a center in the tire circumferential direction, of region sandwiched by the division traces arranged adjacently in the tire circumferential direction, are set as first circumferential end regions R1 and a region sandwiched between the first circumferential end regions is set as a central region Rm, the sipes 53A of the first narrow grooves 50A among the plurality of the narrow grooves provided on the first circumferential end regions, in which the chamfers are formed at groove walls 53Aa near central regions of the sipes are shallower than sipes 53B1 and 53B2 of second narrow grooves 50B1 and 50B2 in which the chamfers are formed in groove walls 53B1a and 53B2a near the division traces of the sipes.SELECTED DRAWING: Figure 9
【課題】トレッドの偏摩耗を抑制し、型開き時のトレッドの欠損やサイプブレードの破損等の不具合を防ぐ。【解決手段】タイヤ周方向に間隔をあけて複数設けられた細溝50と、セクタの分割位置に設けられた分割跡とをトレッドに備え、細溝が、タイヤ軸方向に延びるサイプ53A、53C等と、サイプの接地面8aへの開口端の幅を広げる面取り54A、54C等とを備える。タイヤ周方向に隣り合う分割跡で挟まれた領域のうち、分割跡からタイヤ周方向中央へ向かって第1の角度θ1までの範囲を第1周方向端領域R1、第1周方向端領域の間に挟まれた領域を中央領域Rmとすると、第1周方向端領域に設けられた複数の細溝のうち、面取りがサイプの中央領域側の溝壁53Aaに設けられた第1細溝50Aのサイプ53Aは、面取りがサイプの分割跡側の溝壁53B1a、53B2aに設けられた第2細溝50B1、50B2のサイプ53B1、53B2より浅い。【選択図】図9
PNEUMATIC TIRE AND VULCANIZATION FORMING MOLD
空気入りタイヤ及び加硫成型金型
2024-09-02
Patent
Electronic Resource
Japanese