SU908508A1 - Pressure die-casting device - Google Patents

Description

(54) DEVICE FOR MOLDING UNDER PRESSURE

I

The invention relates to foundry production, in particular to the injection molding of metals and alloys.

A device for injection molding, comprising a mold, in the movable half of which a counter piston is installed, is known. and in a stationary one there is a sprue bushing, a pressing chamber installed in the sprue bushing with the possibility of axial movement, and a crucible with a metal conductor connected to the pressing chamber along the plane of the connector of the press h). When the pressing chamber is filled with a metal, the counter piston closes the feeder of the gating system; when metal is pressed into the mold, the metal conduit is blocked by the pressing chamber 1.

The presence of two moving pairs in the high-pressure zone of the melt is a disadvantage of this device, since it leads to increased volume losses of the melt, and in connection with the wear properties of the elements, the reliability of the pressing system is reduced.

The purpose of the invention is to simplify the design and increase reliability of operation.

This is achieved by the fact that the counter piston is made with a beveled end surface and is mounted with the possibility of psoriot around its axis.

FIG. Figure 1 schematically shows the device in the position corresponding to the filling of the pressing chamber with a melt, a vertical section; Wah FIG. 2 - part of the device in the position corresponding to the beginning of the injection of the melt into the form, section.

15

The device consists of a fixed 1 and a movable 2 half-form with a feeder 3 gating system, a pressing chamber 4 with a press piston 5 and a rod 6, a gating sleeve 7, a counter piece 8 s

30 by a rotation actuator 9 and a heated metal conductor 1O connecting the pressing chamber 4 with the crucible (e shown). The counter piston has a beveled

end surface. An adjustable stop 11 is mounted on the rod 6, and a traveling sensor 12 is mounted on the fixed parts.

The device works as follows.

After the mold is closed, the counter-piston is set to the position indicated in FIG. 1, while the metal conduit 1O communicates with the pressing chamber 4, and the feeder 3 press {) Orma is blocked.

A pressure differential is created between the cavity of the crucible and the pressing chamber 4 (for example, by evacuating the latter), the press piston is moved to the right and the melt begins to fill the pressing chamber. This stage continues until the signal of the track sensor 12 is received. In this case, the dose value is set by placing the stop 11 in the appropriate place. By the signal of the sensor 12, the counter piston is set by the actuator 9 to the position in which the pressing chamber is connected to the feeder 3, and metal pipe is cut off.

Then, the melt is pressed into the mold and pressure drop is released by pressing the pressure chamber. The melt from the metal pipe is returned to the crucible. The residue remaining in the feed channel of the mold is ejected along with the casting.

The invention provides high melt dosing accuracy on injection molding machines with relative simplicity and high reliability.

Claims (1)

1. USSR author's certificate Wo 549250, cl. B 22 D 17/10, 1977. (rig. /