| 摘要 |
PURPOSE:To increase overhung bending strength and to prevent breakage in a connected part by forming a connecting glass layer having large radius of curvature in a connecting end cross section on the bottom side of a beta-alumina tube. CONSTITUTION:The connecting end on the bottom side of a beta-alumina tube is formed in such a shape that when a connecting end curve in a connecting glass cross section is divided by a straight line vertically drawn from the connected end of an insulating ring 11 and a connecting glass 12 to the beta-alumina tube, the relation of the area S1 of a non-glass layer surrounded by the connecting end curve and the straight line and the area S2 of a glass layer surrounded by the beta-alumina tube 10, the connecting end curve, and the straight line satisfies S1<S2, or the relation of a clearance d between the ring 11 at the connecting end of the glass 12 and the tube 10 and radius of curvature rhoin a glass end cross section satisfies 2rho>d. Glass whose thermal expansion coefficient is smaller than that of the beta-alumina tube 10 is used as the connecting glass 12. |
