| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve device to reduce the generation of a shock during a stop of an actuator for a hydraulic cylinder and a hydraulic motor for construction machines. SOLUTION: The valve device comprises a valve body having first and second oil chambers situated in a line to intercouple the switching valve and the actuator; third and fourth oil chambers situated in the second oil chamber and having one end opened to the first oil chamber through the passage of the valve body and communicating with a small size oil passage; a sleeve having a small hole passage communicating with the second oil chamber; the third oil chamber further divided into small oil chambers 1 and 2; a spool communicating with a small hole passage and the second oil chamber through,the small hole passage, blocking the small hole passage through selective slide, and having a through-hole changing a small hole passage opening area by selective glide; in a flow control spool, the fourth oil chamber divided into a spring chamber I and a spring chamber II interconnected through an orifice, the spring chamber II communicating with the second oil chamber through the small hole passage of the sleeve, the small hole passage closed through selective slide, and a through-hole the opening area of which is changed according to a closing amount; and springs by which the flow control spool is pushed, and which are situated in the two spring chambers.
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