| abstract |
A corrugated heat pipe sealed at both ends is disclosed, having a longitudinally corrugated peripheral wall and containing operating liquid therein. The corrugated heat pipe comprises inside a rope-like tension member extending therethrough in its longitudinal direction and secured at both ends. The rope-like tension member has the effect of preventing the corrugated heat pipe from elongation due to the weight thereof when the pipe is inserted in the ground, thus eliminating the possibility of local flattening of the corrugated outer periphery or of breakage of the pipe. Further, even when the coefficient of thermal expansion of the rope-like tension member differs from that of the corrugated heat pipe, since the corrugated heat pipe has its outer periphery corrugated in a wavy form in the longitudinal direction, it can sufficiently absorb the thermal expansion of the rope-like tension member. Thus, the corrugated heat pipe will not be broken, even when the coefficient of thermal expansion of the corrugated heat pipe differes from that of the rope-like tension member. |