| 摘要 |
<p>Unit comprises a piston-cylinder unit (I) sliding on guide bars for the axial injection stroke a screw is pushed by its support bridge which also constitutes the cylinder of the unit. The piston has a hollow piston-rod passing through the cylinder head and attached to the support bridge for the injection barrel whereas the guide bar passes through the hollow piston rod and the rear end cylinder head. The control of the fluid pressure and flow in the piston cylinder unit (I) is provided optionally in one of two ways (according to the purchaser's wishes): either by proportional valves or by a servo valve; with proportional valve control the piston is actively loaded on one side in the chamber towards the piston-rod end. With servo control the piston is of a different form, is double- acting (loaded both sides) and passes through the rear end of the cylinder with a piston dia. exceeding that of the hollow rod. For exacting requirements the servo control can be used; while for less exacting requirements proportional (preset) control is adequate. At the same time, only one basic model is required.</p> |
