PISTON UNIT OF INJECTION MOULDING MACHINE Russian patent published in 2020 - IPC B22D17/20 

FIELD: metallurgy.

SUBSTANCE: invention relates to metal casting under pressure. Piston assembly comprises piston (7), rod (1) with channel (2), disc (5) connected by shank (4) with rod, and pipeline. Sealing element at the rear end of the pipeline is installed in channel (2) with a gap and is permanently fixed by the front end in the blind cavity of disk (5) in the form of continuation of the cavity of shank (4). Front transverse windows (12) of the disc extend into its blind cavity and into the gap between it and the piston. Rear transverse windows (11) of the disc are open to its cavity and annular groove (17) with sealing element (15). In grooves (17) formed by surfaces of piston, rod and disc, longitudinal grooves (16) are made at the ends of disc and connected to piston and open by their rear ends and open in side gap between disc and piston. Bottom of cavity of piston is in contact with front end of disc. Bottom of the piston cavity is made with a seat having a conic bottom, in which a heat insulating material (18) is placed flush with the bottom of the cavity. According to the second embodiment, the disk front end face is made with a socket having a conical bottom, in which heat-insulating material (18) is located flush with the end face.

EFFECT: higher reliability of assembly due to wetting of heat-insulating element.

3 cl, 1 dwg