| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire in which improvement is achieved in wet performance and reduction in vehicle exterior noise while ensuring dry performance. SOLUTION: A fitting direction of sides of the pneumatic tire for a vehicle is designated, in which four main grooves 2a-4d extending in a circumferential direction of the tire are provided on a tread portion 1, two grooves out of these main grooves are located on each side of a tire equator E, five lines of land portions are defined by the main grooves, a center land portion 10 located on the tire equator E is regarded as a rib which continuously extends in the circumferential direction of the tire without being separated, a plurality of arcuate grooves 21, 31 each extending in an arc shape are provided on each of a pair of second land portions 20, 30 located on both sides of the center land portion 10, an end of each of the arcuate grooves is communicated with the main grooves on inside of the vehicle, another end of each of the arcuate grooves is communicated with an adjacent arcuate groove, a repeat pitch Po of the arcuate groove 31 on the second land portion 30 located on outside of the vehicle is set to be greater than a repeat pitch Pi of the arcuate groove 21 on the second land portion 20 located inside the vehicle and a rate Po/Pi is set to be in a range of 1.5-3.0. COPYRIGHT: (C)2009,JPO&INPIT |
