| 摘要 |
<p>PURPOSE:To prevent the penetration of helium from a bonded part as well as to prevent the deterioration in the device of vacuum of a vacuum heat insulating layer by a method wherein the adhesion area of an inner case and an inner case flange is increased. CONSTITUTION:A flange 30 to be used for adhesion is provided on an inner case 2, and the flange 30 and the case 2 are formed into one body. At this time, as the width (l) of the flange 30 is formed narrower by 1-2mm. than the length of a gap 7 and its thickness (t1) is formed as thick as possible. As a result, the cooling of the flange is suppressed, and the possibility of exfoliation of the bonded part is reduced remarkably. The inner case 2 and a flange 8 are press-fitted, adhered and tightened as shown by the arrow in the diagram, and the tightening margin of approximately 0.1mm. or more is provided as before. According to this constitution, the transmission bus length of helium is made longer, and the transmission of helium gas is suppressed.</p> |
