| 摘要 |
<p>The control device is designed to control a hydraulically operated piston unit, particularly the melting and injection screw unit of an injection molding machine for plastics. The control device includes a main control valve reciprocable in a cylindrical guide or bore formed in a valve body, and controlling the connections between a source of hydraulic fluid under pressure, a pressure consumer and a return flow collector for the fluid, each of which is connected to a respective passage communicating with the guide. The main control valve is subjected to axial pressures, variable in at least one stage, to control the connections between the passages. A reversing valve is mounted on the housing to form a unit therewith, and one or more anticipatory control-pressure valves are also mounted on the housing. The reversing valve is effective to reverse the position of the main control valve, while the anticipatory control-pressure valves act on the main control valve to determine the magnitude of the flow area between chambers, each connected to a respective passage in the housing.</p> |
