| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an insulation cylinder, which is made to enhance barrier effect than normal by providing a plurality of recesses on the surface of the insulation cylinder. SOLUTION: A plurality of strip-shaped recesses 15 are formed on the surfaces of an insulation cylinder 1, and the plural recesses 15 are arranged at intervals, and with dashed lines, making their lengthwise directions align with the circumferential direction of the cylinder 1. The recesses 15 provided in dashed lines are arranged in layers in the axial direction of the cylinder 1, and the recesses 15 contained in the adjacent layers are arranged in a zigzag fashion in the circumferential direction.</p> |
