RU2789937C1 - Piston assembly of injection molding machine - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgical production and is suitable as an element of tooling for producing castings on injection molding machines. The piston assembly of the machine contains a piston and a rod connected to each other with a shank on the front end and a longitudinal channel in them with transverse windows in the rear of the first, open into this channel and its bottom; the disk is placed without gaps between the end of this shank and the bottom of the piston cavity and is connected inseparably by the thread of its shank with the threaded surface of the cavity of the shank of the rod; the pipeline is installed in the mentioned channel of the rod and shank with a side gap and fixed permanently with the front end in the cavity of the disk shank: an extension of the blind cavity of the latter; the surfaces of the piston, disk and rod with a chamfer at the base of its shank with inclined transverse windows made on it, opening into the side gap of the assembly, forming a rear annular gap with a sealing element in the annular groove separated by a wall with a side gap from the front end of the rod; this gap is open through the longitudinal windows of the shank of the rod, made in the area of its external threaded surface under the piston, through the lowering of the rear end of the disk at the beginning of the longitudinal windows of the shank into the front annular gap between the side surfaces of it and the piston; the longitudinal windows of the shank are located between the inclined transverse windows of the rod; in the area of intersection of the lateral and end surfaces of the disk, the chamfer is made with the beginnings of transverse inclined windows, open with the ends into its blind cavity.

EFFECT: hardening of the shank of the rod, reducing the length and material consumption of the disk and ensuring high resistance of the shank thread under the piston.

1 cl, 1 dwg

Description

The invention relates to metallurgical production and is suitable as an element of equipment for producing non-ferrous castings on these machines. Known rod of such a machine, on the front of which is placed a hollow piston with a gap between their end and bottom; at the end of the first, a longitudinal channel is formed, in which a tube is fixed with a side gap with a sealing element at the end resting against its conical bottom, where one transverse window is open, and the other into the side gap; transverse windows are formed at the front end of the rod, open into this gap and its sealing element is placed there to seal the piston cooling zone (see patent SU 1783209 A1 dated January 23, 1989). therefore, overheating and destruction of it and the sealing element due to the lack of washing of the latter with refrigerant. Another node is also known, containing a hollow piston and a rod connected to each other with a longitudinal channel and transverse windows open into it and its bottom; disk placed without gaps between the end of the rod and the bottom of the cavity of the piston and connected to the shank of the rod; a pipeline installed in said channel with a lateral clearance and permanently fixed by its front end to the surface of the blind cavity of the disk; formed by the surfaces of the piston, rod and disc rear annular gap with a sealing element in its annular groove; the front end of the disk rests against the bottom of the piston, made in the area of intersection of its side and end surfaces with the front chamfer, the end edge of which is located at the bottom edge of the radius of mating of the side surface and the bottom of the piston cavity, separated from the side surface of the disk by a gap of at least 1 mm; on this chamfer, the beginnings of the front transverse inclined windows are made, open with their ends into the cavity of the disk, connected permanently by a connecting surface with the stem shank, additionally connected to the end of the latter by a chamfer, in which inclined transverse windows open into the longitudinal channel of the rod are made; the disk is made with an external threaded connection for the piston; longitudinal windows are made on the rear end of the disc in the area of its connecting threaded surface, separated from the bottoms of this thread by walls, the rear edges of which are open into the rear annular gap, where the inclined transverse stem windows are also open, and the front edges of these windows are open into the front annular gap through the side an annular groove of the disk formed from the side of its front end (see the decision on the grant of a patent dated September 27, 2021 according to application 2020141322/05 filed on December 14, 2020). Its disadvantages: the length of the disc is commensurate with the length of the piston and its corresponding mass; applicability for units with pistons with a diameter of 40-60 mm.

The task of the proposed solution is to reduce the material consumption and labor intensity of the disc and the use of such a unit in pistons with a diameter of 40-60 mm.

The technical result of the proposed: lower production costs for this unit, suitable for small piston diameters, while ensuring their high durability.

This is achieved by the fact that in the piston assembly of the injection molding machine, containing a piston and a rod connected to each other with a shank at the front end and a longitudinal channel in them with transverse windows in the rear of the first, open to this channel and its bottom; a disk placed without gaps between its front end of the rod and the bottom of the piston cavity, connected permanently with its threaded surface of the cavity with the shank; a pipeline installed in said channel and shank with lateral clearance and permanently fixed with its front end in a blind cavity of the disc; formed by the surfaces of the piston, disk and rod with a chamfer at the base of its shank, on which inclined transverse windows are made, the ends open into the longitudinal channel, the rear annular gap with the sealing element in the annular groove separated by a wall with a side gap from the front end of the rod, open through the longitudinal node windows in the area of the outer threaded surface for the piston, separated from the bottoms of this thread by walls, into the front annular gap between the side surfaces of it and the piston, with a front chamfer made in the area of intersection of its side and end surfaces, the end edge of which is located at the bottom edge of the mating radius the side surface and bottom of the piston cavity, separated from the side surface of the disk by a gap of at least 1 mm, on this chamfer of the disk, the beginnings of transverse inclined windows are made, the ends open into its blind cavity; separated by walls from the bottoms of its outer threads for the piston thread, with open ends into the rear annular groove of the assembly and located between the inclined transverse windows of the rod, the disc rests with its rear end, except for the locations of the beginnings of these windows, connected integrally by the threaded surface of its shank with the same surface of the cavity of the rod shank; at the same time, the front end of the pipeline is permanently fixed in the cavity of the disk shank, which is a continuation of its blind cavity.

The implementation of longitudinal windows in the end of the rod shank, separated by walls from the bottoms of its external thread under the internal thread of the piston, open with the beginnings into the front annular gap, and the ends into the rear annular groove of the assembly, the refrigerant is circulated from the rear end of the piston to its bottom.

The location of the ends of the longitudinal windows of the shank between the inclined transverse windows of the rod creates circulation of the coolant in the circumferential direction in the rear annular gap with cooling of the rear part of the piston. By resting the rear end of the disc against the end of the shank, in addition to the areas where these windows are located, the contact pressure between these surfaces decreases during operation of the assembly, and, consequently, its reliability increases.

The connection of the threaded surface of the disc shank with the same surface of the cavity of the rod shank with additional fixation with a pin ensures the reliability of this assembly during operation and replacement of a worn piston with a new one. By connecting the front end of the pipeline inseparably with the surface of the cavity of the disc shank - the continuation of the blind cavity of the latter - it is easy to assemble it with the rod and vice versa when repairing or preventing this assembly. The claimed solution is new from the known ones, differs significantly from them, is industrially suitable and meets the criteria of the invention. It is represented by the drawing, where in Fig. 1 shows the front part of the piston assembly, containing a rod 1 with a hollow shank 2, in the longitudinal channel of which a pipeline 4 is placed with a side clearance 3, fixed with its front end in the cavity - a continuation of the blind cavity 5 of the disc 6, connected by the thread of its shank 7 to the threaded surface of the cavity 8 shank 2, additionally fixed with a pin 9 with it and rested with its rear end against the end of the shank 2 of the stem 1, where they can be locally connected by welding instead of the pin 9; from the end of the shank 2, longitudinal windows 10 are made, separated by walls from the bottoms of its external thread 11 for the thread of the piston 12 and open with their ends into the rear annular groove 13 of the assembly formed by the surfaces of the disk 6, the piston 12 and the front end of the rod 1 with its chamfer 14 (at the base shank 2) with inclined transverse windows 15, open ends in the side gap 3 of the node and located between the windows 10 (in Fig. 1 they are located in the same longitudinal plane); from the end of the shank 2, the latter are open, for example, by radial depressions 16 of the rear end of the disk 6 into the front annular gap 17 between the side surfaces of the cavity of the piston 12 and the disk 6, which has a chamfer 18 in the front part in the area of intersection of its side and end surfaces; on it are the beginnings of the transverse inclined windows 19, open ends into the blind cavity 5 of the disc 6; the assembly is sealed by the sealing element 20 of the annular groove of the rod 1, separated by a wall from the rear annular gap 13. The piston 12 is cooled as follows: the refrigerant through the side gap 3 of the assembly and then through the inclined transverse windows 15 enters the rear annular groove 13, rushing in the circumferential direction along it to the ends longitudinal windows 10 of the disk 6, through which it rushes to the radial depressions 16 of its rear end and enters the front annular gap 17, rushing along it to the bottom of the cavity of the piston 12, free from the front end of the disk 6; the refrigerant heated by the heat of the piston 12 through the beginnings of the inclined transverse windows 19 located on the chamfer 18 of the disk enters through them into the blind cavity 5 of the disk 6 and is discharged through the pipeline 4 to the rear of the rod with removal through the transverse window beyond it. The efficiency of cooling inside and outside the piston is determined by the thickness of its walls, the flow rate of the coolant and its associated circulation rate through the longitudinal windows of the rod shank and the annular gaps of the assembly; with optimal parameters above the specified, its durability is equal to tens of thousands of pressings of AL alloys into a mold. The proposed longitudinal windows in the rod shank strengthen the latter, reduce the length of the disk by 20%, its material consumption and labor intensity, and this solution is suitable for pistons with a diameter of 40-60 mm. One-piece connection (thread + pin) of the disc and rod shanks or welding between them along their ends eliminates the screwing of the first assembly during operation and guarantees its reliability.

Thus, the proposed solutions strengthen the rod shank, reduce the length and material consumption of the disk, and ensure high resistance of the piston shank thread.

Claims (1)

A piston assembly of an injection molding machine, comprising a piston and a rod connected to each other with a shank at the front end and a longitudinal channel in them with transverse windows in the rear of the rod open into the longitudinal channel and its bottom; a disk placed without gaps between the front end of the rod and the bottom of the piston cavity, connected permanently by its threaded surface in the cavity with the shank; a pipeline installed in said channel and shank with lateral clearance and permanently fixed with its front end in a blind cavity of the disk; formed by the surfaces of the piston, disk and rod with a chamfer at the base of the rod shank, on which inclined transverse windows are made, open ends into the longitudinal channel, the rear annular gap with a sealing element in the annular groove separated by a wall with a side gap from the front end of the rod, open through the longitudinal node windows in the area of the outer threaded surface under the piston, separated from the thread bottoms by walls, into the front annular gap between the lateral surfaces of the rod and piston; a chamfer made in the area of intersection of the side and end surfaces of the disk, the end edge of which is located at the bottom edge of the radius of mating of the side surface and the bottom of the piston cavity, separated from the side surface of the disk by a gap of at least 1 mm, on this chamfer the beginnings of transverse inclined windows are made, open ends into the blind cavity of the disc, characterized in that at the end of the shank with longitudinal windows made in it, separated by walls from the bottoms of the external thread of the shank for the piston thread, with open ends into the rear annular groove of the assembly and located between the transverse windows of the rod, the disc rests with the rear end, except the locations of the beginnings of these windows, connected inseparably by the threaded surface of its shank with the same surface of the shank of the rod in the cavity; while the front end of the pipeline is permanently fixed in the cavity of the disc shank - a continuation of the blind cavity of the disc.

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