| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent heat generation and thermal expansion of heating wires from causing inter-contact and short of the heating wires, by laying a heating wire spirally on the back face of a saddle in a specific interval derived from buckling deformation of the heating wire. SOLUTION: A heating wire 2 is laid spirally on the back face of a saddle in a specific interval H. The interval H of the heating wire 2 is set as h<H<1.5h based on its buckling deformation (h). The buckling deformation (h) is set as h=ΔL/4×(2Lk+ΔL)}<1/2> from theoretical formula of Euler's buckling strength. Where,ΔL is expansion due to thermal expansion of the heating wire 2, and is derived fromΔL=π×D×α×ΔT. Lk is buckling length and is derived from Lk=π×d/4×1/(α×ΔT)}<1/2> . (Where D = diameter of a circle formed by the spirally wound heating wire 2 (mm), d = diameter of the heating wire 2 (mm),α= coefficient of linear expansion ( deg.C<-1> ), andΔT is increased temperature of the heating wire 2 due to flowing current ( deg.C)).</p> |
