| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lightweight piston allowing inexpensive surface treatment, and easily stabilizing an operating feeling. SOLUTION: The surface of the piston 7 made of an aluminum material is subjected to alumite processing, and impregnated with Teflon (R) to form a surface treated layer 14. A rolling seal 8 slidably contacting with the surface treated layer 14 is not subjected to Teflon coating, but brought into sliding contact with the surface treated layer 14.</p> |
