INJECTION MOULDING MACHINE PISTON ASSEMBLY Russian patent published in 2024 - IPC B22D17/20 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgical production and is suitable for piston assemblies of injection moulding machines. Injection moulding machine piston assembly comprises a piston with large and small cavities made at the rear end, based and connected by their side surfaces with corresponding surfaces of the stock and its shank with a threaded seat for a hollow disc shank, changing into a longitudinal blind channel of a rod for a tube placed in it with a side gap, fixed permanently with this shank, connected to the stem shank also permanently. At a disk located without gaps between the end of the stem shank and the bottom of the small cavity of the piston, a chamfer is formed in the area of intersection of the front end with the side surface with beginning of inclined transverse openings, open ends in bottom of common blind cavity of it and shank. Annular gap between the disc and the piston is connected by longitudinal grooves of the stem shank with an annular recess formed at its base with a sealing element and formed therein by transverse openings with their ends extending into disc shank annular recess with longitudinal grooves on it, open front edges into this recess, and rear edges at the end of this shank into the seat of the stem shank. At that, under the piston thread formed from the rear end on the side surface of its large cavity, there is a thread from the front end of the stem, and its shank front wall of annular recess for sealing element is formed with lateral lowering, and from its front end to this wall there are flat longitudinal grooves with their edges open to annular gaps between the side surface of the small cavity of the piston and the disc, as well as this wall. Piston with this surface, having a chamfer from its beginning, is located on this shank from the beginning of this chamfer to the annular recess and on the tops of these grooves from the front end of it and to the ends of their inclined edges located on this wall, with the beginnings of the inclined transverse openings formed on them, the ends coming out into the annular recess of the disc shank, which is open through its longitudinal grooves into the common seat of the shank and the stem, the bottom of which is located at the end of the thread of the latter.

EFFECT: improving reliability and manufacturability of piston and stem with their short threads not washed by coolant and inclined transverse openings of stem shank.

1 cl, 1 dwg