SU551111A1 - Device for protecting metal from oxidation in low pressure casting machines - Google Patents

Description

(54)

DEVICE FOR PROTECTION OF METAL FROM OXIDATION IN MACHINES FOR MOLDING UNDER LOW PRESSURE

The invention relates to the field of foundry, in particular, to machines for compression under low pressure, and serves to protect the metal from oxidation in air. This is especially true for magnesium and s aluminum alloys.

A device for pouring magnesium under low pressure is known. The device is equipped with a metal pipe through which the metal enters the mold. In the upper lateral part 10 of the metal conductor or the sprue bushing, a bore is made for the longitudinal movable in the longitudinal direction and sealing the hole. At the end of the rod there is a hole for the exit 15 of the protective gas through its cavity, which closes when the rod enters the guide hole.

However, in such a device it is impossible to fill the meta-conduit with protective gas directly after the metal is drained, since when the metal level is lowered in the metal pipeline, air is sucked into the latter through gaps in the junction with its shape, and the rod cannot be introduced into the metal conduit and fed into it 25

shielding gas while in meta loprobode h: cold; ts metal. In addition, it is necessary from;: .. the complexity of the seal between the substrates. mto: a reaper and a hole in the metal pipe, because the mating parts are subjected to the type, and chemical impact of living i: r; vp; g,

A device is known for i) with the installation form for casting under low,:: nie. The device contains a promeisug element that is located at the end of the enclosure; form 1 by a metal conduit. Through this propellant element, the forchgu enters before its filling with a melt. Xg inert gas, which;: the air displaces the air from its cavity, 1 ..-. Ny gas is fed through the nozzle into the colpevop channel in the industrial pipe; performed at his os.iovant:, -t zatel-g, radpal.io ras; ms, enters the cavity. this from metalprog.od intermediate :; -: X -; - The cop is separated by a membrane, itOrof.uiH LSI.,. /.,: H; -I is out of paper or another easily taken into account; a. material

However, such a device does not allow i: k: to give gas to the metal pipe to sew: the acid from air oxidation.;. In addition, there is a provision for usganovhe. "A callout of the soJ33KHH - M8ivj5paHa ,, which must be replaced after a cloak of zapiph; When the element is TO4J-ibiiJ element; - contact with the end; - which leads to its rapidity; - wear (sealing of the airtightness of joints 1 will cause leakage of the alloy; the Yci is known for low ionization. The unit contains a stove with a meter and the mold; the crate has a form. The form is equipped a gating valve, which is located in the cavity (chamber), the walls of which are formed by a rigid body with a h / o and a limited on the form side of the membrane, and at the bottom of the chamber, the metal pipeline comes in without direct connection (contact with the sprue bushing. A tube for supplying an inert gas to it is supplied to the chamber. Filling the metal pipe with protective gas after the metal has been drained. However, in this installation, metal is injected into the chamber cavity around the sprue bushing. This leads to 6bicnpoh y deterioration of the chamber and the gating spout, especially the latter, since it contacts with the metal and along the inner surface in the gating orifice. In addition, the camera has a significant HEIGHT; so that when pouring metal, not pop, tal and Tpy6iQ for supplying protective gas and not touching the elastic membrane, and this leads to an increase in the overall dimensions of the machine. The installation requires systems that provide precise pressure control. PIA, in order to prevent metal from entering the trough for supplying protective gas. In addition, heating, periodic cleaning and painting of the chamber are necessary, since the metal enters it when it is poured. The need for 1 camera sealing makes it difficult to inspect, clean and paint during operation. The closest to the technical essence of the device is to protect the metal from oxidation in machines for elbows under high pressure, made in the form of a chamber with a nozzle, supplying a protective gas, located between the heater and the metal conduit; and casting mold. However, this device is complex in design and not very good at work. The goal of this is to eliminate these drawbacks. This is achieved by the fact that the bottom of the chamber is rigidly connected to the lid of the furnace and the head. A part of the camera is made with the ability to telescopically move the cut-off of the meta-conductor and dock with the form. The drawing shows a General view of the device. The device B1 stitches the furnace 1 with the metal pipe 2. The furnace is closed from above with the lid 3. The furnace 4 is fixed on the furnace lid 4, which is rigidly fixed to the furnace lid by means of a flange 5. The walls of the chamber 4 are made of metal and are bellows 2 with the form 7. The form has direct contact with the metal pipe in the area of the filling opening 8. From above, chamber 4 is bounded by an annular hollow spring-loaded device 9, which has a hole around the entire perimeter lOj connecting the cavity of the flange rostranstzom inside the camera. A tube 11 is connected to the flange 9 for the shielding gas. The chamber 4 is in contact with the mold 7 by means of a sub-spring of the flange 9, but has no connection with it. In the cavity of the chamber 4, an emergency metal collector 12 is provided, made 5 in the form of an annular mold placed around the metal conductor. To overlap the top of the chamber 4- in the absence of form 7, before; / - the lid 13 was viewed. The device operates as follows. After the next pouring and discharge of metal into chamber 4, shielding gas flows through pipe 11, which through the gap in junction 6 of metal conduit 2 and form 7 sucks in into the metal duct (gap in junction is gap according to tolerance and it is Oj05-0.2 mm ). The gas entering the metal conduit protects the metal from oxidation by air. Then, the casting mold 7 is raised up using a hydraulic cylinder (not shown in the drawing). In the process of removing the mold 7, the protective gas begins to flow more intensively into the metal pipe through the increasing gap between it. and form. At the same time, the spring-loaded flange 9 of chamber 4 rises slightly up with the form and prevents air from entering the chamber and the meta pipe. If necessary, for example, to reduce the flow of shielding gas, at this moment chamber 4 on the top can be closed with a flap 13. During the next pouring cycle, form 7 pushes onto the metal conduit. 2. But before they dock again, the form is contiguous; with the flange 9 of the chamber 4. At the same time, the protective gas through the lindand hole 8 along; 1, flows into the cavity of the mold 7 and displaces the air from the Benti1 system,