| 摘要 |
A plasticising and injection unit of a plastics injection moulding machine comprises: (a) an electric motor for screw rotation; (b) a hydraulic pump (21) connected to the electric motor (41); and (c) a piston and cylinder unit (24,26) providing linear drive for injection. The hydraulic pump (21) also functions as hydraulic motor and elements, provided for varying the pump or motor flow rate, are connected to a control unit (61). The piston and cylinder unit (24,26) forms a synchronisation cylinder and the hydraulic lines (22,23) indirectly connect the inlets and outlets of the piston and cylinder unit (24,26) and hydraulic pump (21) in a closed circuit. Also claimed is an operating process where the rotational direction of the electric motor remains the same and to allow the movement of the linear drive in both directions, the flow direction of oil inside the pump (21) is reversible and the control of rotational speed and/or torque is effected by the electric motor (41). |
