Energy saving injection unit - comprises a low powered drive which moves and injection unit up to a tool while a short stroke high pressure cylinder retains it

摘要

An injection unit (A) for a plastics injection moulding machine is described and which replaces the large volume cylinder used for nozzle movement and retention of the nozzle against the tool. The movement of the injection unit and nozzle to the injection position is achieved by a low energy power source while a separate power source producing a higher force is used to retain the nozzle against the tool inlet. The power source for the higher load is arranged below the plasticizing unit and at an acute angle to the axis. The hydraulic cylinder used has only a short stroke. For an injection cycle the plasticizing unit moves forward over the cylinder and locates the nozzle against the tool. The cylinder is then supplied with pressure which forces the piston rod against an angled face below the plasticizing unit and hence the nozzle is retained under a high load against the tool. USE/ADVANTAGE - (A) is used in plastics injection machines and saves press energy by replacing the large volume, long stroke cylinder by a dual closure and clamping system.