| 摘要 |
PURPOSE:To realize a lightweight structural member, the strength of which is large, by a structure wherein a square pipe having a quadrilateral cross section made of reinforcing fibers and hardening resin is employed and each corner part is made thicker by swelling inwards the inner wall surface of the corner part. CONSTITUTION:A synthetic resin structural member 1 consists of reinforcing fibers 2, which are uniformly dispersed in hardening resin 3. The constitution of the reinforcing fibers 2, which locate outside a boundary indicated with a dotted line 10 is made to be different from that of the reinforcing fibers 2, which locate inside said boundary. The dotted line 10 partitions the part, which has a uniform thickness along the inner wall surface within the structural member 1, of a swollen part 6. A reinforcing fibers having woven or not-woven fabric structure, in which the reinforcing fibers are oriented longitudinally and laterally in nearly even proportion, are arranged inside the dotted line 10. Outside the dotted line 10, a roving or roll of blind of fibers are arranged so as to shape a form having the cross section of a right-angled triangle and impregnated with hardening resin so as to be set integral with the reinforcing fibers inside the dotted line 10. The swollen part 6 is formed in the scope, which ranges from a position 8, which is one sixth of the length of the side of the original quadrilateral to a position 9, which is one third of the length just mentioned above, from a corner 7 of the original quadrilateral. |
