| 摘要 |
<p>A radial tyre comprising a carcass (9) composed of at least one carcass ply containing cords laid substantially in radial directions and extending under a tread (4) through sidewalls (5) to bead regions (6) and wrapped at each edge around bead cores (7), and a belt (14) composed of at least three belt plies (10a...10d) containing belt cords laid radially outside said carcass (9) and under said tread (4) at an acute angle to the circumferential direction of the tyre wherein in the standard state of the tyre inflated to its standard internal pressure mounted on its standard rim (2), a carcass profile defined by a centre line passing through the centre of the said carcass (9) in its thickness is characterised by having an upper region (C1) curved convexly outwardly and defined as between a belt outer edge point (a) at which a vertical line (K1) extending in the radial direction from an axial outer edge (e) of a belt ply (10c) having the narrowest width amongst the three belt plies (10a, b and c) counted from the carcass side intersects the carcass (9) and a maximum width point (b) of said carcass at an overall maximum width point (f) of the tyre; a lower region (C2) curved convexly outwardly and defined between the carcass maximum width point (b) and an inflection point (c) on the carcass the height of which from a bead rim seat (2a) of said rim (2) in the radial direction is 1.6 times the flange height (H1) of said rim (2); and a bead region (C3) curved convexly inwardly and defined between said inflection point (c) and a contacting point (d) at which said carcass (9) contacts the bead core (7), the upper region (C1) overlapping a single curvature having a radius (R1) for the range of more than 90% thereof, the lower region (C2) overlapping a single curvature having a radius (R2) for the range of more than 90% thereof, the ratio R1/R2 of said radius (R1) to said radius (R2) being 0.95 to 1.08 and the ratio TR1/SW of the radius (TR1) of curvature of the tread surface to the tyre maximum width (SW) which is the distance between said overall maximum width points (f) in the said standarfd state being 1.28 to 1.95.</p> |
