| 摘要 |
<p>In a swing arm, a pair of left and right arm portions (35L, 35R), a pivot portion (36) which is formed on the front ends of the arm portions, an axle support portion (37) which is formed on the rear ends of the arm portions, and a hollow cross portion (38) which connects the arm portions, are integrally formed with each other by moulding. A pair of left and right support bosses (39) for supporting a shock absorber is integrally formed on a wall (38b, 38a) of the cross portion (38). An opening portion (44) whose peripheral portion is endlessly contiguously formed is formed by the pivot portion (36), the cross portion (38) and the arm portions (35L, 35R). A pair of left and right recessed portions (42), which are indented toward a support boss (39) side, are formed on the inner surface of the wall (38a) on which the support bosses (39) are formed, and a pair of left and right reinforcing ribs (43), each of which is positioned laterally outside of a recessed portion (42), are integrally formed on the inner surface of the wall (38a) on which the support bosses (39) are formed, projecting toward the inside of the cross portion (38).</p> |
