| 摘要 |
PROBLEM TO BE SOLVED: To provide a cylinder block for reducing a friction due to the slide of a piston.SOLUTION: In a cylinder block 10, a cross hatch 14 having a cross hatch angle &thetas; within the range of 130° to 150° is formed on the inner peripheral surface of a cylinder 13. A groove 17 extending between two ends of the cylinder 13 to constitute the cross hatch 14 has a plurality of bent portions 18 bent midway of the groove 17. |
