GB1559956A

GB1559956A - Die-casting installation

Info

Publication number: GB1559956A
Application number: GB16778A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-01-04
Filing date: 1978-01-04
Publication date: 1980-01-30

Description

(54) DIE-CASTING INSTALLATION (71) We, SERGEI GEORGIEVICH GLAZU NOV, of kvartira 62, Leninsky prospekt, 41, ALEXEI MIKHAILOVICH KHROMOV, of kvartira 19, ulitsa Ukhtomskaya, 36a, VASILY VLADIMIROVICH MERKULOV, of kvartira 27, korpus 2, 3 Dorozhny proezd, 10, IGOR BORISOVICH KRJUCHKOV, of kvartira 68, korpus 16, Begovaya ulitsa, 22, NIKOLAI EGOROVICH KLIMOV, of kvartira 253, korpus 4, Aviamotornaya ulitsa, 4, and DMITRY ALEXANDROVICH FILIPPOV, of kvartira 138, Saratovskaya ulitsa, 8/10, all of Moscow, all Union of Soviet Socialist Republics, all citizens of the Union of Soviet Socialist Republics, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to installations for die-casting of metal blanks, e.g. for casting precision blanks from high-melting- point and high-reactive metals and alloys based on, say, titanium or zirconium.

Known in the prior art is an installation for die-casting of metal blanks (see. for example, U.K. Patent No. 914508). This iustallation comprises a pressure tight zasing mounted on a frame and two vertical immovable plates interconnected by horizontal guide columns which accommodate a third movable plate provided with a reciprocating drive.

An electrode holder mounted in the melting portion of the installation is intended to hold a consumable electrode and to supply electric current to the latter. A melting pot is arranged under the consumable electrode and is secured on a horizontal axle which is linked kinetically with a reversible rotation drive for turning said melting pot around the horizontal axis in order to pour out molten metal and to return the pot to the initial position. The melting pot has a chute for pouring out molten metal, and a funnel installed in a hole located in the side wall of the pressing cylinder.

The shell of the pressing chamber is built into the vertical stationary plate adjoining the melting portion of the installation. The pressing cylinder receives a pressure piston of the hydraulic cylinder for forcing molten metal from the pressing cylinder into the die. The pressing cylinder is in communication with the die, one half of which is provided with a gate bushing and is Rigidly secured to the stationary plate adjoining the melting portion of the installation.

The other half of the die is fixed to the movable plate enclosed into the pressure tight casing of the installation.

However, in the installation with this type of casing, such parts of said installation as the movable plate and its kinematic linkage with the reciprocating drive work in vacuum.

This hampers servicing a number of installation mechanisms and offers additional difficulties in vacuumizing the internal space of the installation.

To counter this disadvantage, there appeared installations wherein the casing of the casting chamber is separated from the melting chamber and is made air-tight.

Nevertheless, such installations also have a disadvantage residing in an imperfect design of the pouring device which interferes in some respects with normal functioning of the installation. For example, each time after the molten metal has been fed into the pressing cylinder through the funnel, the inside walls of said funnel become covered with a crust of hardened metal. This crust prevents the next portion of molten metal from being delivered into the pressing cylinder. After two or three pourings, the outlet hole of the funnel ;becomes completely obstructed by the crust of solidified metal and the installation ceases to function.

In order to replace or clean the funnel, the installation has to be devacuumized, the clogged funnel has to be removed, replaced by a clean one, the installation has to be sealed again and evacuated. All these operations take much time. The down-time of the installation caused by replacement and cleaning of funnels leads to losses of working time of the attending personnel and to the need for additional equipment which, taken together, makes the blank-casting process considerably more expensive.

In spite of the aforesaid disadvantages, installations for die-casting of blanks have become increasingly popular in recent years.

This can be attributed to the development of machine-building and a high demand for diecast blanks, so that the provision of a continuous die-casting installation proves to be pressing necessity.

The present invention provides an installation for die-casting of metal blanks, comprising a horizontally movable vertical plate provided with a reciprocating drive and carrying a die holder holding one half of a die whose other half is fastened to one side of a stationary vertical plate, a vacuum casting chamber defined between the plates and having a pressuretight casing enclosing the die, a pressuretight casing of o vacuum melting chamber secured to the other side of the stationary plate, the stationary plate accommodating a pressing cylinder whose wall has a hole for receiving a selected one of the funnels of a pouring device comprising at least two funnels and a mechanism for moving the funnels in the vertical and horizontal directions, the pressing cylinder receiving a piston of a hydraulic linear actuator for feeding molten metal into the die through a gate bushing, an electrode holder, and a melting pot installed with a provision for turning around a horizontal axis in order to discharge into the selected funnel both the electrode holder and the melting pot being located in the vacuum melting chamber above the pouring device.

The provision of the pouring device with additional funnels and a mechanism which moves them to the required position allows the process of casting metal blanks to be conducted for a long time without devacuumization. This, in turn, increases the output of the installation and dispenses with manual labour for replacing the funnels.

It is expedient for the funnels of the pouring device to be mounted on a mounting member and spaced at a given pitch along a horizontal arc, the mounting member being carried by a vertical shaft connected with a longitudinal motion drive, a sleeve mounted on the shaft being provided with a lever for turning the mounting member in a horizontal direction. Such a mechanism for moving the funnels of the pouring device is simplest from the viewpoint of design and sufficiently reliable.

It is expedient that the lever for turning the mounting member should be provided with a built-in retainer in the form of a spring-loaded bar passing through a hole in the wall of the sleeve which fits around a case rigidly connected with the casing of the vacuum melting chamber and provided with sockets to receive the free end of the bar. The retainer makes it possible to secure the funnels in the required position.

The installation can be provided with at least one appliance for cleaning the funnels, the appliance comprising a hydraulic cylinder with a piston rod fastened to the casing of the vacuum melting chamber, and carrying a scraper, and a bar carrying a grip and secured with the aid of a ball joint permitting longitudinal displacement. Such an arrangement will allow the funnels to be cleaned alternately of the crust of solidified metal without disturbing the vacuum in the melting chamber, simultaneously feeding molten metal from the melting pot into the pressing cylinder through another clean funnel. As a result, each funnel can be alternately cleaned and used repeatedly during continuous functioning of the installation.

Now the invention will be described in detail, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a side view of a die-casting installation with partial cut-outs and a partial longitudinal vertical section through portions of the melting and casting chambers; Fig. 2 is a top view of the same installation with a partial longitudinal section taken along line Il-il in Fig. 1; Fig. 3 shows the pouring device with a mechanism for moving the funnels, viewed from the melting pot; Fig. 4 shows the pouring device, with a mechanism for moving the funnels, a side view with partial cut-outs and a number of vertical sections; Fig. 5 is a top view of the funnels secured to a sector; and Fig. 6 is a side view of the appliance for cleaning the funnels of the pouring device, in vertical section.

The installation for die-casting of metal blanks comprises a frame 1 (Fig. 1), and two vertical plates 2 and 3 secured rigidly on the frame and interconnected by horizontal guide columns 4 (Fig. 2) on which is mounted a movable plate 5 provided with a reciprocating drive 6. Mounted on the stationary vertical plate 2 is a pressure tight casing of a vacuum melting chamber 7 (Fig.

1) which is divided in a lateral direction and consists of an upper part 8 (cover) and a lower part 9. The vacuum melting chamber 7 accommodates an electrode holder 10 intended to hold a consumable electrode 11 and to supply electric power to it from a source of electric power (not shown). Installed under the consumable electrode 11 is a melting pot 12 secured on a horizontal axle 13 (Fig. 2) which is kinematically linked with a drive 14 for turning the melting pot 12 relative to the horizontal axis.

At the side of the discharge chute of the melting pot 12 is a funnel 15 (Figs. 3 and 4) of a pouring device, the funnel 15 being inserted in a hole 16 in the wall 17 of a pressing cylinder 13 (Fig. 1 and 2). The pouring device has at least two funnels 15 (Fig. 5) and a mechanism 19 (Fig. 3 and 4) for moving the funnels in horizontal and vertical directions with a view to inserting them alternately into the filler hole 16.

The mechanism 19 comprises a mounting member or sector 20 (Fig. 5) for mounting funnels 15 at a given pitch or spacing along a horizontal arc, the sector being secured on a vertical shaft 21 (Fig. 4) which is kinematically linked with a longitudinal motion drive 21. The shaft 21 carries a sleeve 23 with a lever 24 for turning the sector 20 in a horizontal direction. After the sector 20 has been turned through the desired angle, it can be fixed in place by a retainer 25 in the form of a spring-loaded bar 26 passing through the sleeve 23 and entering sockets 27 made in a stationary case 28 which is secured on the part 9 of the casing of the vacuum melting chamber 7 (Fig. 1).

The installation comprises at least one appliance for cleaning the funnels 15 (Fig.

6); the appliance consists of a scraper 29 (Fig. 6) mounted on the piston rod 30 of a hydraulic cylinder 31 and a grip 32 installed on a bar 33 and connected by means of a bal joint which permits longitudinal displacement of the bar 33 with the grip 32; the scraper and grip are secured, respectively, on the parts 9 and 8 of the vacuum melting chamber 7 (Fig. 1) and inserted into it.

An inspection port 35 (Fig. 1) serves for watching the work of the cleaning appliance.

The filling funnels 15 (Fig. 5) are arranged on the sector 20 at such a distance from one another as to ensure coaxial position of the funnel 15 being cleaned between the scraper 29 (Fig. 6) and the grip 32 while the clean funnel 15 is in the filler hole 16 (Fig. 3) in the wall 17 of the pressing cylinder 18.

The wall 17 (Fig. 1) of the pressing cylinder 18 is built into the immovable plate 2.

At the side of the vacuum melting chamber 7 the wall 17 receives the pressure piston 36 of a hydraulic cylinder 37 for forced feed of melten metal into a die 38 (Fie. 2) through the gate bushing 39.

The half 40 of the die 38 with the gate bushing 39 is secured on the immovable plate 2 (Fig. 1). The other die half 41 (Fig.

2) is fastened in a die holder 42 on the movable plate 5.

The die 38 is enclosed into the pressure tight casing of a vacuum casting chamber 43 (Fig. 1), the casing consisting of a part 44 in the form of bellows and a part 45 integral with the die holder 42. Secured to the vertical movable plate 5, on the outside relative to the part 44 of the casing of the vacuum casting chamber 43, is a hydraulic cylinder 46 whose rod interacts with a pusher 47 entering the die 38 (Fig. 2).

Pressure tightness of the parts 8 and 9 (Fig. 1) of the casing of the vacuum melting chamber 7 and of the parts 44 and 45 of the vacuum casting chamber is ensured by special vacuum seals 48 (Fig. 1) and 49 (Fig. 2).

The installation functions as follows.

First. a vacuum is built up in the melting and casting vacuum chambers 7 and 43 (Fig.

1) with the aid of vacuum pumps (not shown). Then the drive 6 is turned on and moves the plate 5 towards the plate 2 until the halves 40 (Fig. 2) and 41 of the die 38 are tightly closed.

One of the funnels 15 of the pouring device is set in position for feeding metal into the pressing cylinder 18. Then electric current is fed to the electrode holder 10 (Fig.

1) for melting the consumable electrode 11 by the heat liberated by the electric arc between the electrode 11 and the slag which covers the lining of the melting pot 12. The process of melting of the consumable electrode 11 continues until the amount of molten metal accumulated in the melting pot 12 becomes sufficient for filling the die 38 (Fig. 2). Then the consumable electrode 11 (Fig. 1) is lifted out of the melting pot 12.

The melting pot 12 containing metal is turned with the aid of the drive 14 (Fig. 2) and axle 13 around its horizontal axis and the molten metal is drained through the discharge chute of the melting pot 12 (Fig. 1) into the funnel 15 and further into the pressing cylinder 18. Then the hydraulic cylinder 37 with the pressure piston 36 is set in operation and this piston delivers a portion of molten metal into the die 38 (Fig. 2). The blank is held in the die 38 long enough for shaping the blank and cooling it to the preset temperature.

Unloading of the metal blank from the die 38 is carried out by turning on the drive 6 and withdrawing the plate 5 from the plate 2.

While the die 38 is opening, the hydraulic cylinder 46 is set in operation for pushing the metal blank from the movable half 41 of the die 38. Then the die 38 is cleaned of splashed metal.

The cleaned halves 40 and 41 of the die 38 are closed by the drive 6 which propels the movable plate 5 towards the immovable plate 2. Simultaneously, the drive 22 of the mechanism 19 in the vacuum melting chamber 7 (Fig. 1) raises the sector 20 (Fig. 4) with the filling funnels 15, after which the sector 20 is turned horizontally by the lever 24 through a preset angle and the used funnel 15 is withdrawn sideways from the pressing cylinder 18 (Fig. 3) to the point of location of the scraper 29 (Fig. 6) and grip 32 for cleaning the funnel 15 of metal crust.

Inasmuch as the funnels 15 are set at a given distance from one another, the funny withdrawn for cleaning is replaced by the next clean funnel 15 above the hole 16 (Fig.

3 and 4) in the wall 17 of the pressing cylinder 18.

The clean funnel 15 is lowered by the drive 22 into the filler hole 16 of the wall 17 of the pressing cylinder 18.

This completes the working cycle of the installation. The following cycles can be performed without devacuumization, provided the cast blanks remain in the vacuum chamber 43, so that the installation, as confirmed by operational tests, can work for a long time, ensuring a high quality of the cast blanks and a higher efficiency than the known installations of the same application.

WHAT WE CLAIM IS:- 1. An installation for die-casting of metal blanks, comprising a horizontally movable vertical plate provided with a reciprocating drive and carrying a die holder holding one half of a die whose other half is fastened to one side of a stationary vertical plate, a vacuum casting chamber defined between the plates and having a pressuretight casing enclosing the die, a pressuretight casing of a vacuum melting chamber secured to the other side of the stationary plate, the stationary plate acccommodating a pressing cylinder whose wall has a hole for receiving a selected one of the funnels of a pouring device comprising at least two funnels and a mechanism for moving the funnels in the vertical and horizontal directions, the pressing cylinder receiving a piston of a hydraulic linear actuator for feeding molten metal into the die through a gate bushing, an electrode holder, and a melting pot installed with a provision for turning around a horizontal axis, in order to discharge into the selected funnel both the electrode holder and the melting pot being located in the vacuum melting chamber above the pouring device.

2. An installation as claimed in claim 1, wherein the funnels of the pouring device are mounted on a mounting member and are spaced at a given pitch along a horizontal arc, the mounting member being carried by a vertical shaft connected with a longitudinal motion drive, a sleeve mounted on the shaft being provided with a lever for turning the mounting member in a horizontal direction.

3. An installation as claimed in claim 2, wherein the lever is provided with a retainer in the form of a spring-loaded bar passing through a hole in the wall of the sleeve which fits around a case rigidly connected with the casing of the vacuum melting chamber and having sockets to receive the free end of the bar.

4. An installation as claimed in any of claims 1 to 3, provided with at least one appliance for cleaning the funnels which comprises a hydraulic cylinder with a rod carrying a scraper and a bar carrying a grip and secured with the aid of a ball joint permitting longitudinal displacement, both the hydraulic cylinder and the bar being mounted on the casing of the vacuum melting chamber.

5. An installation for die-casting of metal blanks, substantially as described herein with reference to, and as shown in, the accompanying drawings.

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Claims

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pressing cylinder 18 (Fig. 3) to the point of location of the scraper 29 (Fig. 6) and grip 32 for cleaning the funnel 15 of metal crust.

Inasmuch as the funnels 15 are set at a given distance from one another, the funny withdrawn for cleaning is replaced by the next clean funnel 15 above the hole 16 (Fig.

3 and 4) in the wall 17 of the pressing cylinder 18.

The clean funnel 15 is lowered by the drive 22 into the filler hole 16 of the wall 17 of the pressing cylinder 18.

This completes the working cycle of the installation. The following cycles can be performed without devacuumization, provided the cast blanks remain in the vacuum chamber 43, so that the installation, as confirmed by operational tests, can work for a long time, ensuring a high quality of the cast blanks and a higher efficiency than the known installations of the same application.

WHAT WE CLAIM IS:- 1. An installation for die-casting of metal blanks, comprising a horizontally movable vertical plate provided with a reciprocating drive and carrying a die holder holding one half of a die whose other half is fastened to one side of a stationary vertical plate, a vacuum casting chamber defined between the plates and having a pressuretight casing enclosing the die, a pressuretight casing of a vacuum melting chamber secured to the other side of the stationary plate, the stationary plate acccommodating a pressing cylinder whose wall has a hole for receiving a selected one of the funnels of a pouring device comprising at least two funnels and a mechanism for moving the funnels in the vertical and horizontal directions, the pressing cylinder receiving a piston of a hydraulic linear actuator for feeding molten metal into the die through a gate bushing, an electrode holder, and a melting pot installed with a provision for turning around a horizontal axis, in order to discharge into the selected funnel both the electrode holder and the melting pot being located in the vacuum melting chamber above the pouring device.
2. An installation as claimed in claim 1, wherein the funnels of the pouring device are mounted on a mounting member and are spaced at a given pitch along a horizontal arc, the mounting member being carried by a vertical shaft connected with a longitudinal motion drive, a sleeve mounted on the shaft being provided with a lever for turning the mounting member in a horizontal direction.
3. An installation as claimed in claim 2, wherein the lever is provided with a retainer in the form of a spring-loaded bar passing through a hole in the wall of the sleeve which fits around a case rigidly connected with the casing of the vacuum melting chamber and having sockets to receive the free end of the bar.
4. An installation as claimed in any of claims 1 to 3, provided with at least one appliance for cleaning the funnels which comprises a hydraulic cylinder with a rod carrying a scraper and a bar carrying a grip and secured with the aid of a ball joint permitting longitudinal displacement, both the hydraulic cylinder and the bar being mounted on the casing of the vacuum melting chamber.
5. An installation for die-casting of metal blanks, substantially as described herein with reference to, and as shown in, the accompanying drawings.