| 摘要 |
<p>This spool valve (V1) is provided with a valve element (11) and a cylinder (12) that has an interior hole (12a) that contains the valve element (11) such that said valve element (11) can move axially. In this spool valve (V1), when the valve element (11) moves along the cylinder (12) in the axial direction from an initial position, a supply valve opening (Vi) opens between the valve element (11) and the cylinder (12) and a hydraulic fluid is introduced from a hydraulic source into a hydraulic chamber via said supply valve opening (Vi). The fluid passage formed on the hydraulic-chamber side of the supply valve opening (Vi) is provided with a narrowed section (O1) wherein: the area of the opening formed between the valve element (11) and the cylinder (12) is constant in an effectively-narrowed region in which the valve element (11) has moved no more than a prescribed axial amount from the initial position thereof; and the area of the aforementioned opening increases in a not-effectively-narrowed region in which the valve element (11) has moved more than said prescribed axial amount. This makes it possible to suppress oil hammer in the hydraulic chamber to which the hydraulic fluid is supplied via this spool valve (V1).</p> |
