| 摘要 |
PURPOSE:To improve the operating velocity of a cylinder by forming a bottomed spool hole inside both a piston engaged in a cylinder housing and a piston rod exposed from both sides of said piston, and engaging a motor-controlled spiral spool in the spool hole. CONSTITUTION:A cylinder housing 10 is internally divided into two hydraulic chambers 22 and 24 by a piston 18 engaged in said housing. Each of the chambers 22 and 24 are capable of making connection to a pump 32 at ports 26 and 28 via a pilot type three-way valve 30. A bottomed spool hole 40 is formed inside the housing 10, extending within the total length of the piston 18 and the piston rods 20 and 21, and contains a spiral spool 42. A sleeve 59 having two ports 60 and 62 is formed at the central part of the spool hole 40. The piston 18 and the spiral spool 42 turned by an electrically powered motor 70 define a three-way valve 68 which changes the alternative communication state among three ports, that is, the open parts of the ports 60 and 62 and the spool hole 40 with respect to an oil chamber 54.
|
