摘要 |
<p>Hydraulic controls for the injection unit of an injection molding machine of the type which has tandem supporting bridges rining on two guide rods and hydraulic cylinder assemblies surrounding the rods the cylinder assemblies in the rear supporting bridge which control the movements of the plastification screw being convertible from single-acting cylinders to double-acting cylinders with a differential piston, for the selective connection to a first hydraulic control system which has presettable proportional-response control valves for the adjustment of the pressure and flow rate of the hydraulic fluid, or to a second hydraulic control system which provides a continuous electronic control input to a servo-valve, adjusted by an electronic feedback loop with pressure transducers. The conversion involves the exchange of a piston and a cylinder cover in the two cylinder assemblies of the rear supporting bridge.</p> |