Injection unit comprising a spindle drive and hydraulic support
AssigneeBosch Rexroth AG
InventorJoerg Dantlgraber
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Abstract
Disclosed is an injection unit (1) for an injection molding machine, comprising a screw (4) that is driven by means of a spindle drive (18). The spindle drive (18) is driven via an electric motor (6). Additionally, a force that acts in an axial direction is transmitted to the screw of the injection unit (1) via a hydraulic cylinder (38). According to the invention, a pump (48, 68) is driven via the electric motor (6). A pressure chamber (44) of the cylinder (38) can be supplied with more pressurizing means via said pump (48, 68) than is needed during an axial displacement of the plunger (36).
Claims9
An injection unit of an injection molding machine, comprising a screw adapted to be axially driven by means of a spindle drive that is not self-locking and is rotatably driven by a motor, and to which a hydraulic cylinder for generating an axial force acting on the spindle drive is associated, characterized in that the motor drives a pump means whereby a first pressure chamber of the hydraulic cylinder may be supplied with more pressure medium than is needed during the axial displacement of the cylinder.
Dependencies are inferred from the claim text.