Pneumatic tire for automobile

Abstract

Abstract PURPOSE:To prevent wear from occurring, by changing a gradient of groove walls in each main groove into the specified angular range along the zigzag main groove, in case of pneumatic tire installing the zigzag main groove, whose amplitude is set down to less than one-third of pitch length, in a tire circumferential direction. CONSTITUTION:Treads 11 of a pneumatic tire have three zigzag main groves 12 ranging in a tire circumferential direction, and the amplitude is set to an extent of less than one-third of pitch length. In this case, a gradient of each of groove walls 12a and 12b of the main groove is continuously varied along the main groove 12. And, at the inside of a plane surface passing a tire turning axial center, a gradient of each of groove walls 12a and 12b against a normal P perpendicular to a surface of each tread 11 is set to maximum at crest parts 13a and 14a of each of ribs 13 and 14 while minimum at crest parts 13b and 14b, respectively. In addition, the maximum gradient thetaa ia set so as to become 20- 40 deg., the minimum gradient thetab -10-15 deg. and a difference between both these angles thetaa and thetab more than 8 deg., respectively.

Inventors

• 👤 Hiroshi Nakamura
• 👤 博司 中村

Bibliographic Details