GB2103973A - A metal pouring vessel melt supply system - Google Patents

Abstract

A vessel (10) for use in the pouring of molten metal in a casting operation in a foundry plant comprises a container body (14) for containing molten metal, the body (14) having an outlet (40) from which the molten metal may be poured, mounting means (17, 18) mounting the body (14) for movement about first and second generally horizontal axes (T1, T2). This allows the depth of molten metal in the vicinity of the outlet to be controlled. Further, in a melt supply system, a mould is conveyed along a track to a pouring station where it is filled from a pouring vessel which is tiltable about a horizontal axis. Molten metal is supplied to the pouring vessel from ladles or preferably from a furnace by means of a launder such that the vessel may be supplied simultaneously with pouring the mould. The vessel may be mounted on rails such that its position relative to the mould is adjustable and that removal of the vessel from the pouring station to remove solidified material is facilitated. <IMAGE>

Description

SPECIFICATION Improvements relating to casting This invention is concerned with improvements relating to casting.

In a conventional casting operation, sand moulds are conveyed on a track through a pouring/casting station, at which molten metal is poured into the moulds.

Conventionally molten metal is produced in a cupola, and is fed by means of launders to a holding furnace. In an automated or semiautomated system, ladles carried by an overhead crane are utilised to transfer molten metal to the moulds, under the control of an operator. Since it is not acceptable to fill a mould with molten metal other than in a single operation, the ladles must be capable of carrying more than sufficient molten metal to fill a mould, and the remnant material in the ladle (referred to on solidification as a "skull") is poured away, to be returned to the cupola.

This conventional operation has many disadvantages, some of which are as follows:- (a) The operation is labour intensive. To avoid slowing down the moulding track, it is usual to utilise two ladles, each under the control of one operator, so that as one is being returned to the holding furnace for refilling, the other is being used to fill a mould with molten metal. Even so on occasion, a mould may inadvertently be missed, causing unnecessary expense because the mould is subsequently knocked-out, for the sand to be reformed into a new mould.

(b) The feeding of molten metal from the holding furnace to the moulds by the use of ladles is slow, cumbersome, dangerous, and wasteful of heat; (c) Because the operation is under the control of an operator, if the operator is not very skilled the likelihood of a badly poured mould being produced is quite high.

It is an object of the present invention to overcome or reduce some of the disadvantages associated with conventional casting operations.

According to a first aspect of this invention, we provide a vessel for the pouring of molten metal comprising a container body for containing molten metal, the body having an outlet from which the molten metal may be poured, mounting means mounting the body for movement about first and second generally horizontal axes.

The pouring vessel is adapted most conveniently for the pouring of molten metal into moulds in a casting operation, but may be utilised to advantage in other operations in which the pouring of quantities of molten metal under controlled conditions is necessary.

By the use of such a vessel, by movement of the body about the first of said axes, the depth of molten metal in the body in the vicinity of the outlet may be changed, so that a pouring operation (conveniently effected by movement of the body about the second of said axes) takes place under conditions in which the depth of molten metal in the vicinity of the outlet is as may be desired, irrespective of changes in the total quantity of metal in the body.

Preferably said axes are substantially mutually at right angles, or lie in substantially mutually perpendicular planes.

Conveniently the body is elongate, that is having one horizontal dimension (herein referred to for convenience as its length) greater than the other horizontal dimension (herein referred to for convenience as its width).

Thus preferably one of said axes (the second axis) is generally aligned with the length of the body, so that movement about such axis in a pouring operation produces movement of molten metal in the body in a direction widthwise of the vessel. In this way, the creation of "slop" on pouring may be reduced.

On the other hand, where the other of said axes (the first axis) is generally aligned with the width of the body, movement of the body about the first axis in a depth-adjusting operation produces movement of molten metal lengthwise of the vessel, allowing the desired depth to be attained in the vicinity of the outlet over the pouring of a large quantity of molten metal.

If required, the vessel may have one or more internal baffles to reduce "slop" on movement of the body about the first axis.

Movement of the body about said first axis may be achieved by the use of a hoist (connectable such as by the provision on the body of a shackle) but preferably by fluid operated means such as an hydraulic ram, and movement of the body about said second axis may also be achieved by fluid operated means (e.g. an hydraulic ram).

Preferably the body is mounted on wheels whereby the position of the vessel in relation to a desired pouring location may be adjusted, although if required the vessel may be permanently fixedly mounted at a pouring station.

Conveniently, both the outlet of the body and the first axis are located adjacent to a forward end of the vessel.

Preferably the body is of a size adapted to hold a large quantity of molten metal. By the term "large" we means a quantity greater than two tons, preferably greater than three tons.

Since the vessel carries such a large quantity of molten metal, problems of lack of homogenisation, as may be encountered in the use of a conventional smaller vessel for the pouring of molten metal, such as a ladle, are reduced.

Preferably the vessel comprises heating means whereby molten metal in the body may be heated.

In this manner, the requirement to empty the vessel of its contents within a specified period is obviated.

The outlet may be afforded by a pouring spout, preferably extending transversely of the vessel (viz. in a widthwise direction) and preferably extending upwardly from a lower internal part of the body, advantageously through a horizontal baffle. In this manner, pouring is effected from a part of the body which is effectively isolated from the upper surface of the molten metal in the body, minimising the possibility of slag being poured into the mould.

Preferably the vessel comprises a further outlet, conveniently extending longitudinally, through which slag and residual molten metal may be poured from the body by movement thereof solely about said first axis.

Preferably the body is provided with an opening comprising feed means into which molten metal may be fed for the supply of the molten metal into the body, conveniently supply being in the form of a continuous stream, or a semi-continuous stream, such as from a cupola or holding furance by way of a launder.

Such feed means is preferably of such configuration as to enable a stream of molten metal to be delivered to the vessel, over at least most of the range of pouring positions adopted by the body in use. In this manner, use of the pouring vessel in the filling of mould need not be interrupted for the replenishment of molten metal.

According to a second aspect of this invention, we provide a method of casting comprising the steps of conveying a foundry mould to a pouring station, at which a pouring vessel located said vessel comprising a container body mounted for tilting movement about a fixed horizontal axis, supplying molten metal to the body, and tilting the body about said axis to cause a stream of molten metal to issue from an outlet of the body into the mould.

Preferably a sufficient quantity of molten metal is supplied to the body to enable a number of moulds to be filled without having to supply further molten metal to the vessel.

Preferably said horizontal axis extends generally parallel to a track on which the mould is conveyed in the vicinity of the pouring station.

The pouring vessel may be mounted on rails which extend alongside the track whereby the position of the vessel may be adjusted lengthwise of the track in relation to a mould at the pouring station. By this means also, the vessel may be moved away from the pouring station to enable solidified material, formed as drips or skulls, to be removed.

In carrying out the method, molten metal may be supplied to the body in batches, for example by the use of one or more ladles, but preferably is supplied from a furnace (which may be a holding furnace or a cupola) along a channel as a stream, conveniently by the use of a launder. Preferably the construction and arrangement of the pouring vessel, and delivery means utilised, is such as to enable molten metal to be delivered to the body of the pouring vessel simultaneously with use of the pouring vessel to fill a mould with molten metal.

Preferably in carrying out the method in accordance with the second aspect of this invention, the vessel used is one which has one or more of the features described above in relation to the first aspect of the invention.

According to a third aspect of the invention, we provide foundry plant comprising: (a) a track along which a mould is movable to a pouring station, at which molten metal may be poured into the mould; (b) a furnace in which a first quantity of molten metal is contained; (c) a pouring vessel at the pouring station in which a second quantity of molten metal, smaller than said first quantity, is contained, said vessel being mounted alongside the track and having an outlet to enable molten metal to be poured from the vessel into a mould; (d) at least one feed channel between the furnace and the pouring vessel, along which a stream of molten metal may be supplied to the vessel.

The furnace may be a holding furnace, or may be a cupola. Conveniently the feed channel is provided by a launder, which may be provided with heating means, and covering means to reduce heat losses from the molten metal.

Preferably means are provided (being in the form for example of a gate) to regulate the amount of, or prevent, molten metal flowing along the feed channel, to replenish the store of molten metal in the vessel.

Preferably the vessel of the third aspect of the invention comprises one or more of the features described above in relation to the first aspect of the invention and the plant preferably comprises features adapted to facilitate the performance of one or more of the steps described in relation to the second aspect of this invention.

There will now be described, with reference to the accompanying drawings, a foundry plant, a pouring vessel, and a method of casting all of which are aspects of the present invention.

In the accompanying drawings: FIGURE 1 is a plan view, with a top part removed, of a pouring vessel which is, and/or forms parts of, and/or which is utilised in the performance of the invention; FIGURE 2 is a section on the line Il-Il of the pouring vessel of Figure 1, but showing the top part in position, FIGURE 3 is a front view, partly in section taken on the line Ill-Ill of Figure 2; and FIGURE 4 is a fragmentary plan view of a part of the top part of the vessel.

Referring now to the drawings a pouring vessel 10 comprises a base framework 11, mounted on flanged wheels 1 2, for movement along rails 1 3.

Mounted on the framework 11 for relative movement thereto, about two mutually perpendicular horizontal axes, is a hollow body in the form of a tank 14. The tank 14 is lined with heat insulating and refractory material shown generally at 15 and has a lid 12, also lined.

At a forward end the vessel 10, the framework 11 comprises a pair of spaced brackets 1 6 having bearings, which carry a first front mounting assembly 1 7 for rotation about a first horizontal axis T,. A second front mounting assembly 1 8 is carried by the assembly 1 7 for rotation about a second horizontal axis T2 (Figure 2) which extends at right angles to the axis T,, the second mounting assembly 1 8 being fixed to the tank 14. Thus the front end of the tank 14 is supported by assemblies 17 and 18.

At a rear end of the vessel 10, a similar arrangement is provided comprising a first rear mounting assembly 1 9 and a second rear mounting assembly 20 supporting the tank 14 at the rear end thereof for movement about second axis T2.

The framework 1 1 is provided at the rear with a mast 24 relative to which a carriage 25 is movable, the carriage carrying brackets 26 in which the first rear mounting assembly 19 is mounted whereby as the carriage is raised the tank 14 is lifted at the rear end and the body 12 pivots about axis T1.

Because the carriage 25 moves vertically relative to the mast 25, the second rear mounting assembly 20 can pivot relative to the first rear mounting assembly 19, about a further horizontal axis T3.

Between the second rear mounting assembly 20 and a platform part 28 of the carriage 25 on which the brackets 26 are mounted, a double acting hydraulic ram 30 extends, the ram 30 being mounted to one side of a vertical plane containing axis T2.

Thus as fluid under pressure is admitted to the ram 30, by way of a conduit (not shown) either to extend or to retract the piston 31 thereof relative to the cylinder 32, under the control of an operator by the use of a control valve V the body 10 is caused to pivot about axis T2. Such hydraulic systems are well known, and thus further description is not considered necessary.

The mast 24 provides guide flanges 29 for wheels W of the carriage 25 to facilitate movement of carriage 25 relative to mast 24.

Extending between the carriage 25 and the framework 11 is a further hydraulic ram 33, also controlled from control valve V by an operator. The valve V is located on an operator's platform 34 secured via the mast 24, to the framework 11.

When the ram 33 is extended, the carriage 25 moves upwards vertically to raise the rear end of the vessel 10 and thus the vessel pivots about axis T1.

it will be appreciated that axis T2 will no longer be exactly horizontal, but as the amount of lift of the rear end of the vessel 10 which is usually achieved during pouring, is relatively small, axis T2 will remain generally horizontal.

Provided in a side wall of the tank 14 adjacent the top thereof is an outlet opening 40, from which a pouring spout 42 extends generally transversely of the tank 14 (see Figures 1 and 3), the spout 42 having a feed pipe 44 extending upwardly from a lower interior portion of the tank 14 to the opening 40.

In the use of the pouring vessel 10 illustrated in the accompanying drawings, particularly in carrying out the method which is the preferred embodiment of this invention, the rails 13, extend alongside a mould track 60. Molten metal is delivered to the tank 14 from a furnace, such as a cupola or a holding furnace, by way of a heated launder 50, molten metal flowing from the launder into a front feed means comprising an opening 48.

The tank 14 is preferably of a size, to be able to receive up to 4 tons of molten metal, or more, but preferably not less than 2 tons. 3 tons is an average size.

As shown in Figure 4, the end of the launder 50 is adjacent the axis T, so that the opening 48 remains in a substantially constant position irrespective of the lifting and lowering of the rear end of the tank 14.

When it is desired to pour molten metal from the pouring vessel 10 into a mould stationary at a position alongside the vessel 1 9 on the track 60, with the tank 14 filled to a desired level, fluid under pressure is applied at the command of the operator to the ram 30, to cause tilting of the tank 14 in an anti-clockwise direction (Figure 3) about the axis T2. Molten metal thus issues from the pouring spout 42 into the adjacent mould.

As the level of molten metal within the tank 14 falls towards a minimum acceptable level as metal passes out of the tank 14, for example after the filling of one or several moulds, the ram 33 is operated to lift the tank 14 at the rear end. The extent to which the rear end of the tank 14 is lifted will depend on the quantity of molten metal left in the tank 14, and the desired level to which it is desired to raise the level of molten metal in the front end of the tank 14. At the command of the operator, at the same time or subsequently, fluid under pressure may again be supplied to the ram 30, to cause the piston 31 thereof to further retract to cause further tilting of the tank 14 in an anti-clockwise direction about the axis T2, so that further molten metal may be poured from the pouring spout 42 into the or another mould, at that time adjacent to the pouring spout 42.The height of molten metal in the front end of the tank 14 may be maintained constant by the elevation of the rear end of the tank 14, and thus the velocity with which molten metal will issue from the pouring spout 42 may thus be maintained constant.

It can be seen that the pouring spout 42 is arranged so as to be longitudinally aligned with the axis T1, as best shown in Figure 1 so that variation in the angle of the tank as a result of raising or lowering the rear end by the ram 33, does not alter the longitudinal position of the pouring spout 42.

Moreover, as best shown in Figure 3 at 43, a horizontal plane through the axis T2 is just above or in line with the refractory lined surface of the pouring spout 42 when the tank 14 is in its pouring position (shown in chain dotted line in Figure 3). When the tank 14 is in a ready-to-pour position, shown in full lines in Figure 3 the pouring spout 42 is angled slightly upwardly.

In the event that it is desired to discharge molten material from the tank (which may be residual, unwanted molten metal, or may be slag) not through spout 42, the hydraulic ram 33 is operated to raise the tank 14 at the rear end, sufficiently for molten material to flow out through the feed means 48. If necessary, the launder 50 may be elevated to enable this to be achieved.

In use, by tilting of the tank 14 about the transverse axis T1, a sufficient "head" of molten metal is obtained to effect pouring from the spout 42, whilst the provision of the feed pipe 44 ensures that such molten metal flows from within the molten metal in the tank 14, as distinct from the surface of the molten metal. In this manner it is ensured that no "slag" which floats on the molten metal, is poured into any of the moulds.

The tank 14 may be provided with internal vertical or horizontal baffles, as required to reduce the tendency of molten metal within the tank to "slop".

The pouring vessel 10 may be moved longitudinally relative to the mould track 60 on the rails 13, manually, or by a further ram 40 connected to the framework 11 and the ground, enabling the pouring vessel 10 to be positioned to accurately align the spout 42 with a mould, and to enable residual material, which may have conglomerated in the vicinity of the vessel 10 to be cleaned up.

The pouring vessel 10 is provided with gas or other heating means, one gas burner being shown at G by way of example, to retain the quantity of molten metal within the tank 12 sufficiently heated particularly, for example, when making S.G. iron. In this manner the pouring vessel may be utilised to fill a plurality of moulds over an appreciable time period without the metal solidifying. Of course, the insulation 1 5 assists in this.

If desired, instead of feeding the tank 14 directly from a cupola via a launder, metal may be tapped from a cupola into ladles where it may be treated, for example by desulphurisation and recarburisation to make S.G. iron, and the treated metal subsequently poured from the ladles into the tank.

Although hydraulic means have been described for enabling the vessel 12 to be pivoted about axes1, T2 of course, any other means may be utilised as required. For example, instead of providing mast 24, if required, the rear end of tank 14 may be raised by means of a hoist or jack, although the arrangement described above is preferred.

Furthermore, it is not essential to the invention for the vessel to be movable on rails 1 3. If preferred the vessel 12 may be permanently fixedly mounted at a pouring station.

Claims (31)

1. A vessel for the pouring of molten metal comprising a container body for containing molten metal, the body having an outlet from which the molten metal may be poured, mounting means mounting the body for movement about first and second generally horizontal axes.

2. A vessel according to Claim 1, wherein the first and second axes are substantially mutually at right angles, or lie in substantially mutually perpendicular planes.

3. A vessel according to Claim 1 or Claim 2 wherein the body is elongate (as herein defined), and one of said axes (the second axis) is generally aligned with the length of the body, so that movement about such axis in a pouring operation produces movement of molten metal in the body in a direction widthwise of the vessel.

4. A vessel according to Claim 3 wherein the other of said axes (the first axis) is generally aligned with the width of the body so that movement of the body about the first axis produces movement of molten metal lengthwise of the vessel.

5. A vessel according to any one of the preceding claims wherein movement of the body about said first axis is achieved by the use of fluid operated means.

6. A vessel according to any one of the preceding claims wherein movement of the body about said second axis is achieved by fluid operated means.

7. A vessel according to any one of the preceding claims wherein the body is mounted on wheels whereby the position of the vessel in relation to a desired pouring location may be adjusted.

8. A vessel according to any one of the preceding claims wherein both the outlet of the body and the first axis are located adjacent to a forward end of the vessel.

9. A vessel according to any one of the preceding claims wherein the body is of a size adapted to hold a large (as herein defined) quantity of molten metal.

10. A vessel according to any one of the preceding claims wherein the vessel comprises heating means whereby molten metal in the body may be heated.

11. A vessel according to any one of the preceding claims wherein the outlet is afforded by a pouring spout.

1 2. A vessel according to Claim 11 wherein the pouring spout extends transversely of the vessel.

1 3. A vessel according to Claim 11 or Claim 12 wherein the pouring spout extends upwardly from a lower internal part of the body.

14. A vessel according to any one of Claims 3 to 1 3 where dependent on Claim 3 wherein the vessel has a further outlet extending longitudinally through which slag and residual molten metal may be poured from the body by movement thereof solely about said first axis.

1 5. A vessel according to any one of the preceding claims wherein the body is provided with an opening comprising feed means into which molten metal may be fed for the supply of the molten metal into the body.

1 6. A vessel according to Claim 1 5 wherein the feed means is of such configuration as to enable a stream of molten metal to be delivered to the body, over at least most of the range of pouring positions adopted by the body in use.

1 7. A method of casting comprising the steps of conveying a foundry mould to a pouring station at which a pouring vessel is located, said vessel comprising a container body mounted for tilting movement about a fixed horizontal axis, supplying molten metal to the body, and tilting the body about said axis to cause a stream of molten metal to issue from an outlet of the body into the mould.

18. A method according to Claim 1 7 wherein a sufficient quantity of molten metal is supplied to the body to enable a number of moulds to be filled, without having to supply further molten metal to the vessel.

19. A method according to Claim 17 or Claim 1 8 wherein said horizontal axis extends generally parallel to a track on which the mould is conveyed in the vicinity of the pouring station.

20. A method according to Claim 1 9 wherein the pouring vessel is mounted on rails which extend alongside the track, whereby the position of the vessel may be adjusted lengthwise of the track in relation to a mould at the pouring station.

21. A method according to any one of Claims 1 7 to 20 wherein molten metal is supplied to the body from a furnace along a channel as a stream.

22. A method according to Claim 21 wherein the construction and arrangement of the pouring vessel, and supply means utilised, is such as to enable molten metal to be delivered to the body of the pouring vessel simultaneously with use of the pouring vessel to fill a mould with molten metal.

23. A method according to any one of Claims 17 to 22 utilising a vessel accordion 9 to any one of Claims 1 to 16.

24. Foundry plant comprising: (a) a track along which a mould is movable to a pouring station, at which molten metal may be poured into the mould; (b) a furnace in which a first quantity of molten metal is contained; (c) a pouring vessel at the pouring station in which a second quantity of molten metal, smaller than said first quantity, is contained, said vessel being mounted alongside the track, having an outlet to enable molten metal to be poured from the vessel: (d) at least one feed channel between the furnace and the pouring vessel, along which a stream of molten metal may be supplied to the vessel.

25. Foundary plant according to Claim 24 wherein the furnace is a holding furnace, or a cupola.

26. Foundary plant according to any one of Claims 24 to 25 wherein means are provided to regulate the amount of, or prevent, molten metal flowing along the feed channel to replenish the store of molten metal in the vessel.

27. Foundary plant according to any one of Claims 24 to 26 wherein the vessel comprises one or more of the features claimed in any one of Claims 1 to 17.

28. A pouring vessel substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

29. A method of casting substantially as hereinbefore described with reference to the accompanying drawings.

30. Foundry plant substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

31. Any novel feature or novel combination of features hereinbefore described and/or shown in the accompanying drawings.