| 摘要 |
1. A tyre (1) having a body (2) and a crown reinforcement (10) arranged on the body (2), the body (2) having two sidewalls (4), two beads (3) having each a reinforcing ring (6) and a crown (5), the crown (5) of the body (2) being formed of three zones located below the crown reinforcement (10), namely two side zones (Z1 ) close to the edges (15) of the crown reinforcement (10) and a central zone (Z2 ) adjacent to the side zones (Z1 ), the body (2) being without reinforcement structure in the sidewalls (4) and in the crown (5), the concavity of the sidewalls (4) facing the inside of the type (1), characterized by the following features : a) the thickness e0 of the body (2) along the edges (15) of the crown reinforcement (10) and the thickness e1 of the body (2) at any point in each of the side zones (Z1 ) are related by the relationship : 0.6 e0 =<e1 =<e0 ; b) the width I1 of each side zone (Z1 ) and the width L of the crown (5) of the body (2) are related by the relationship : 0.02 L=<I1 =<0.30 L ; c) the average thickness e2m of the body (2) in the central zone (Z2 ) and the thickness e0 of the body (2) along the edges (15) of the crown reinforcement (10) are related by the relationship : e2m =<0.5 e0 ; d) each inner connection angle beta is defined by the relationship : 90 degrees =<beta =<110 degrees ; e) the crown reinforcement (10) has two crossed plies (11, 12), the angle of each ply (11, 12) being at least equal to a minimum value alpha m and at most equal to a maximum value alpha M such that : alpha m = alpha 0 /2 ; cos alpha M =0.9 cos alpha 0 ; the angle alpha 0 being defined by the relationship : see diagramm : EP0098459,P7,F2 in which rho s represents the radius of curvature of the ply in question (11, 12), Rs represents the distance of said ply (11, 12) from the axis XX' of the tyre (1), Re represents the distance from the axis XX' of the tyre (1) of the points A, B where the body (2) has the greatest width in a radial section, the straight line AB being parallel to the axis XX' of the tyre (1). |
