PURPOSE: To enable reversible deformation of a non-circular outer wall and adjust a change of load by providing a hollow space filled with incompressible fluid between concentric double walls composed of an inner pipe having a circular section of a hollow structural member and an outer pipe having the different sectional shape from that of the inner pipe, and increasing internal pressure of fluid.
CONSTITUTION: A pipe resistant to torsion, usable as a steering shaft for a truck is provided with a concentric double wall structure composed of an inner pipe 1 and an outer pipe 2, the pipe in the non-loaded state is provided with the inner pipe 1 having a circular sectional shape and the outer pipe 2 having an elliptic sectional surface. An intermediate space 3 between them is filled with incompressible fluid having the large coefficient of compression, the sectional shape of the outer pipe 2 approaches to a circular shape by pressure rise of fluid in the intermediate space 3, and torsional rigidity of an elastic reversible material part is increased. A change or rise of pressure of fluid in the intermediate space 3 of the pipe is achieved by a hydro-pneumatic method and can be switched by closing and opening of a simple valve. Therefore, rigidity of the hollow structural member can be set to such magnitude as to withstand the normal load even in the case where maximum load is applied.
HANSUUFURIIDORITSUHI JIIGURING
BUIIRI MARUTEIN
KURAUSU DOREHISURAA
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