US 5,773,050 AGranted

Mould closing device for an injection moulding machine

AssigneeKrauss-Maffei Aktiengesellschaft

InventorWalter Wohlrab

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Abstract

A mould closing device for an injection moulding machine includes a fixed (1) and a movable (4) mould clamping plate for support of screw drives (36) which are freely rotatable in the fixed mould clamping plate (1) and axially supported in one direction and supported in spindle nuts (39) secured in the movable mould clamping plate (4). Provided for actuation of the screw drives (36) for the closing and opening stroke of the movable mould clamping plate (4) are a rotary drive (44) and a hydraulic piston-cylinder unit (45, 46) interacting with the screw drives for effecting the closing force build-up. To ensure a dimensioning of the actuating drive of the screw drives substantially in accordance with the requirements for rapid opening and closing motions while the hydraulic piston-cylinder unit maintains a high closing pressure, it is proposed to form the hydraulic piston-cylinder unit of one or more pistons and hydraulic cylinders, with the admission of pressure medium for effecting the closing pressure build-up being effected by piston-cylinder units which are driven by the screw drives via interposed pressure transmitting devices (19).

Claims9

Dependent claims

A mould closing device for an injection moulding machine having a fixed mould clamping plate supporting one tool half and a movable mould clamping plate carrying another tool half, said mould closing device comprising:

at least one piston-column unit of a first type having one end secured in the movable mould clamping plate and another end received in a first main cylinder secured to the fixed mould clamping plate;
at least one piston-column unit of a second type having one end secured in the movable mould clamping plate at a distance to the piston-column unit of the first type and another end received in a second main cylinder secured to the fixed mould clamping plate;
a screw drive mechanism for moving the moveable mould clamping plate with respect to the fixed mould clamping plate to thereby effect a rapid closing and opening of the tool halves, said first type of piston-column unit being provided for support of the screw drive mechanism;
and
force application means for buildup of a clamping force when the tool halves abut each other through operation of the screw drive mechanism, said force application means including a pressure amplifying unit acted upon by hydraulic fluid under pressure, without subjecting the screw drive mechanism to the application of the clamping force, said second type of piston-column unit being provided for support of the pressure amplifying unit.

2 more elements

Dependencies are inferred from the claim text.