RU2492024C1 - Moulding chamber of injection moulding machine - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, particularly, to cooling and lubing of horizontal injection moulding machine pistons. Moulding chamber has inlet opening communicated with its axial cavity 2 to receive the melt and separated from chamber rear end by web 4. Top part of said web has transverse opening 5 for lubing open to annular groove 6 made at the surface of aforesaid cavity 2. Groove 6 communicates via lengthwise or inclined grooves 7 with chamber rear end. Front ends of said inclined grooves 7 are located above there rear ends. Lubricant fed via opening 5 flows into chamber bottom end to lube piston front part before pouring the melt therein.

EFFECT: ruled out ingress of lubricant into chamber axial cavity and pinholes in casts.

3 cl, 4 dwg

Description

The group of inventions relates to metallurgical production, in particular to devices for cooling and lubricating the pistons of horizontal injection molding machines.

A device is known for cooling and lubricating the piston of a horizontal injection molding machine (RU 2045370 C1, B22D 17/22, 10/10/1995). The device comprises: a piston with channels for draining the cutting fluid from its cavity to the outer side surface; a rod placed in front of the piston cavity; a pressing chamber, in the cavity of which this piston moves from the rear to the front and back, and the supply of cutting fluid to the channels of the rod and piston at the corresponding moment in the cycle of operation of this machine.

The disadvantages of the device: the complexity of the design and the presence of residual cutting fluid in the pressing chamber after the piston is returned to the rear position, which affects the quality of the obtained castings by gas porosity.

A device is known for lubricating the piston of a horizontal injection molding machine in the form of a pressing chamber (see appendix p. T18.1 of the passport of a Czech machine of the CL00 250-25-B2 series, Vihorvlat n.p.Snina), adopted as a prototype. The pressing chamber contains an axial cavity for the alloy and the piston into which the casting window is open, this window is separated from the rear end of the chamber by a jumper, and in the area of the latter there are transverse lubricant windows; two in the upper half, and the third in the lower half, they are open in an annular groove formed on the surface of the axial cavity.

The disadvantages of the prototype are that the lubricant supplied through the transverse windows of the lintel enters not only the lateral surface of the piston, but also into the axial cavity of the chamber, where it burns out when the alloy is poured into it through the filling window, which leads to an increase in gas porosity and marriage of the obtained castings, the presence of such windows and an annular groove complicates the design and increases the complexity of manufacturing the camera.

The group of inventions solves the problem of improving the quality of the obtained castings by gas porosity.

The technical result obtained by the implementation of the group of inventions is to prevent lubricant from entering the axial cavity under the alloy being poured.

The specified technical result is achieved in that in the pressing chamber of a horizontal injection molding machine having an axial cavity for the alloy, a filling window open into the cavity and separated from the rear end of the chamber by a jumper, a transverse lubricant window extending into the annular groove on the surface of this cavity new is that the transverse lubricant window is located at the top of the jumper, and the annular groove is connected to the rear end of the chamber by longitudinal or inclined grooves, with the latter having front ends wife over the rear.

The specified technical result is achieved in that in the pressing chamber of a horizontal injection molding machine having an axial cavity for the alloy, a filling window open into the cavity and separated from the rear end of the chamber by a jumper, a transverse lubricant window extending into the annular groove on the surface of this cavity new is the fact that the transverse window for lubrication is located in the upper part of the jumper, and the transverse window for lubrication and the annular groove are made without a rear wall.

The annular groove can be made of variable depth: maximum - at the rear end and minimum - at its front wall.

The execution in the pressing chamber of a transverse lubricant window located in the upper part of the jumper allows you to create a container for the supplied lubricant and ensure its draining under the influence of gravity and heat from the chamber and the piston by the gap between the piston surfaces and the annular groove into the lower part of the axial cavity and lubrication of the front of the piston in the rear position. In addition, the design is simplified and the manufacturability of the pressing chamber is increased.

The execution of longitudinal or inclined grooves connecting the annular groove with the rear end of the chamber allows the excess lubricant to be removed outside the chamber, which eliminates the interaction of the lubricant with the alloy poured into the chamber through the casting window and improves the quality of castings, for example, by gas porosity.

In the absence of a rear wall at the annular groove and when performing a transverse lubricant window without a rear wall, the design of the proposed chamber is further simplified and its manufacturability is also increased, and the lubrication efficiency of the front of the piston is increased by increasing the width of the groove and the absence of walls separating adjacent longitudinal or inclined grooves, and excess grease from such a groove is freely discharged behind the rear end of the chamber.

An annular groove can also be made of variable depth: maximum at the rear end of the chamber and minimum at the front wall.

Technical solutions with features distinguishing the claimed solution from the prototype are not known and do not follow explicitly from the prior art. This suggests that the claimed solution is new and has an inventive step.

The invention is illustrated by drawings, where

figure 1 is a longitudinal section of the rear of the pressing chamber (with longitudinal grooves);

figure 2 is a longitudinal section of the rear of the pressing chamber (with inclined grooves);

figure 3 is a longitudinal section of the rear of the pressing chamber (a transverse window for lubrication and an annular groove made without a back wall);

4 is a longitudinal section of the rear of the pressing chamber (the transverse lubricant window and the annular groove are made without a rear wall, the groove of variable depth).

According to the first embodiment, the pressing chamber has a pouring window 1, open in its axial cavity 2 under the alloy and a piston 3, which is in it in the rear position before pouring the alloy. Window 1 is separated from the rear end of the chamber by a jumper 4. In the upper part of the jumper 4 there is a transverse lubricant window 5, the dimensions of this window exceeding the dimensions of the three windows of the prototype. The window 5 is open into an annular groove 6 formed on the surface of the axial cavity 2 of the chamber. The groove 6 through the longitudinal or inclined grooves 7 is connected to the rear end of the pressing chamber (when making inclined grooves 7, their front ends are located above the rear).

According to the second variant, the pressing chamber has a pouring window 1, open in its axial cavity 2 under the alloy and a piston 3, which is in it in the rear position before pouring the alloy. Window 1 is separated from the rear end of the chamber by a jumper 4. In the upper part of the jumper 4 there is a transverse lubricant window 5, the dimensions of this window exceeding the dimensions of the three windows of the prototype. Window 5 is made without a back wall. The annular groove 6 is made of constant depth and also without a back wall.

In this case, the lubricant supplied, for example, with a flat longitudinal jet from the corresponding geometry of the feed tube fills the gaps between the surface of the annular groove 6 and the side surface of the front part of the piston 3 and flows along them into the lower part of the cavity 2 of the chamber and the piston, lubricating this part of the piston around the perimeter , and excess grease is removed by gravity behind the rear end of the pressing chamber.

The proposed design solutions provide reliable and efficient lubrication of the front of the piston 3 by draining lubricant from the transverse window 5 and the upper part of the annular groove 6 into its lower part, followed by the removal of excess grease from the rear end of the chamber due to the grooves 7 or the annular groove 6 without the rear wall, and the depth such a groove is constant or variable and grows toward the rear end of the chamber. Such solutions minimizes the ingress of grease through the gaps between the side surfaces of the piston 3 and the cavity 2 into the area of the filling window 1.

These structural measures simplify the manufacture of the chamber due to the absence of rear walls at the annular groove 6 and the transverse window 5, or these elements have rear walls and then the grooves connect the annular groove 6 to the rear end of the chamber.

The device according to the first embodiment works as follows.

At the beginning of the operation of the injection molding machine, the piston is in the rear position, the lubricant is automatically supplied through the tube from the corresponding container to the transverse window 5 of the jumper 4, which performs the function of a container for lubrication. From it, the grease in the gaps between the surfaces: the side piston 3, the annular groove 6 and the longitudinal or inclined grooves 7 flows into the lower part of the cavity 2, lubricating the front side part of the piston located in the pressing chamber. In this case, excess lubricant is discharged along the grooves 7 behind the rear end of the chamber, thereby eliminating or minimizing the ingress of lubricant into the axial cavity 2 under the alloy. After pouring the alloy into the pressing chamber through the window 1, the piston 3 moves from the rear to the front position along the cavity 2 of the chamber, lubricating its lateral surface with grease located on its lateral surface and thereby reducing friction between the inner surface of the pressing chamber and the piston 3. Moreover, when moving the piston, the rest of it, located behind the rear end of the chamber, is lubricated with grease of the transverse window 5 and grooves 7. After removing the casting block from the mold, the piston 3 returns to its original position (which shows but Figures 1-2) and its rear end clears the cavity 2 of the alloy residues and grease, removing them from it. Further, the above is repeated.

The device according to the second embodiment works as follows.

At the beginning of the operation of the injection molding machine, the piston is in the rear position, the lubricant is automatically supplied through the tube from the corresponding container to the transverse window 5 of the jumper 4, which performs the function of a container for lubrication. From it, the lubricant in the gaps between the surfaces: the side piston 3, formed when the groove 6 is made of constant or variable depth, increasing towards the rear end of the pressing chamber, flows into the lower part of the cavity 2, lubricating the front side of the piston located in the pressing chamber. In this case, excess lubricant is discharged through the gaps when grooves 6 are made of constant or variable depth and without the rear wall beyond the rear end of the chamber, thereby eliminating or minimizing the ingress of lubricant into the axial cavity 2 under the alloy. Moreover, when moving the piston, the rest of it, which is located behind the rear end of the chamber, is lubricated by lubrication of the transverse window 5 and grooves 6 without rear walls. After removing the casting block from the mold, the piston 3 returns to its original position (as shown in FIGS. 3-4) and, with its rear end, cleans the cavity 2 from the remnants of the alloy and lubricant, removing them from it. Further, the above is repeated.

By lubricating the piston 3, and the surface of the cavity 2 of the pressing chamber, the friction forces between them are also reduced, and the pressure of the alloy is pressed into the mold is stable, which guarantees the quality of the obtained castings by porosity, which is also reduced by the proposed solutions by minimizing ingress of grease from the annular groove 6 into the cavity 2 due to the removal of its excess through the corresponding channels for the rear end of the pressing chamber.

Thus, the proposed technical solution improves the quality of the obtained castings in terms of gas porosity due to the minimum amount of grease that enters the filling window when the piston is lubricated; its design is simplified by the presence of only one transverse window - a lubricant reservoir - in its upper part, which, like the annular groove, can be without a back wall, which increases the manufacturability of this pressing chamber.

Claims (3)

1. The pressing chamber of a horizontal injection molding machine having an axial cavity under the alloy, a filling window open in the cavity and separated from the rear end of the chamber by a jumper, a transverse lubricant window extending into the annular groove on the surface of this cavity, characterized in that the transverse window for lubrication is located in the upper part of the jumper, and the annular groove is connected to the rear end of the chamber by longitudinal or inclined grooves, with the latter having front ends above the rear. 2. The pressing chamber of a horizontal injection molding machine having an axial cavity for alloy, a filling window open in the cavity and separated from the rear end of the chamber by a jumper, a transverse lubricant window extending into the annular groove on the surface of this cavity, characterized in that the transverse window for lubrication is located in the upper part of the jumper, and the transverse window for lubrication and the annular groove are made without a rear wall. 3. The pressing chamber according to claim 2, characterized in that the annular groove is made of variable depth, maximum at the rear end and minimum at its front wall.

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