Injection assembly for pressure die casting systems
AssigneeIdra S.R.L.
InventorsFiorenzo Dioni, Richard Oberle
Life of this patent
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Abstract
An injection assembly, for pressure die casting systems, has an injection cylinder adapted to inject liquid metal into a casting cavity; the injection cylinder is actuated by a hydraulic flow of an oil-pressure controlled circuit; the oil-pressure controlled circuit includes a hydraulic cushion which blocks and releases the flow of the hydraulic fluid in the injection cylinder and provides a counter-pressure of preset value to control the injection speeds and to prevent cavitation in the injection cylinder.
Claims4
An injection assembly for pressure die casting systems, said injection assembly comprising an injection cylinder adapted to inject liquid metal into a casting cavity, said injection cylinder being actuated by a hydraulic flow of an oil-pressure controlled circuit;
- said injection cylinder comprising an injection piston which forms a piston side chamber and an annular chamber;
- said oil-pressure controlled circuit comprising a hydraulic cushion which blocks and releases flow of a hydraulic fluid exiting said annular chamber of said injection cylinder;
- said hydraulic cushion providing a counter pressure, in said annular chamber of said injection cylinder, of a preset value to control injection speeds and to prevent cavitation in said annular chamber of said injection cylinder;
- said hydraulic cushion comprising a cylindrical body which contains a stem provided with a piston and moving axially in said cylindrical body;
- said piston comprising a resting surface opposed to said stem;
- said resting surface being 35% smaller than an opposing surface of said stem;
- said piston dividing an internal volume of said cylindrical body into a reduced chamber and into a larger chamber;
- wherein said piston of said hydraulic cushion comprises said resting surface opposed to said stem;
- and said resting surface being smaller than a surface of said stem and configured to close an inlet of said reduced chamber,
- wherein said oil-pressure controlled circuit comprises a single control valve which is inserted in input between an accumulator of hydraulic fluid and said injection cylinder;
- said single control valve controlling a profile of an injection process,
- the injection assembly comprising a first check valve inserted in said oil-pressure controlled circuit between said single control valve and said injection cylinder,
- wherein said annular chamber of said injection cylinder is connected to said accumulator by a first duct to a second duct provided with a second check valve, and a third duct.
Dependencies are inferred from the claim text.