EP1299202B1 - Method and device for uphill casting, comprising a chill or core stackings with an open pouring gate - Google Patents

Abstract

A method for uphill/low-pressure casting, especially of light metal alloys, with a casting table having a flow-through opening, with a casting furnace lying below the casting table with a riser pipe forming an upwardly open mouth opening, with a mould having a base plate which has a downwardly open pouring-in opening; the mouth opening is positioned against the flow-through opening in a sealing fashion from below, the mould is brought with its pouring-in opening over the flow-through opening, melt is conveyed from the casting furnace via the riser pipe into the mould until it is filled, the mould is displaced horizontally on the casting furnace with open melt-filled communication between the casting furnace and the mould until the pouring-in opening is closed by the casting table below and the flow-through opening is closed by the base plate above, the melt is allowed to drop in the riser pipe as far as below the mouth opening.

Description

The invention relates to a method and an apparatus for increasing casting, especially for casting light metal alloys. Compared to gravity casting, this has been increasing Pour the essential benefit of a calmed controlled Gießverlaufs. Thereby the air bubble entry and the oxide skin entry, with every swirl of the melt when pouring is avoided. When using core packages as Casting molds can detach and entrain molded material be avoided in the gate and in the pouring run, otherwise to Reduces the quality of the castings.

It is generally disadvantageous with increasing pouring that the Solidification process can be waited for up to 15 minutes must be removed before the currently filled mold and the next one Casting mold can be brought over the casting furnace. Around To remedy this disadvantage, it has already been proposed Molds immediately after low pressure casting in the gate to be closed and immediately removed from the riser pipe.

Methods are known from DE 198 21 419 A1 and from DE 198 07 623 A1 of the type mentioned, in which boxless bales of form (Core packages) or molded boxes with each open at the bottom Pouring opening over the mouth of the riser pipe of a casting furnace be pushed under a conveyor for these shaped bales (Core packages) or molded boxes. After the rising pouring is first a closure at the top of the riser closed before the form bale (core package) or the form box transported on and by a next following one is replaced.

The invention is based on a method and a task Device of the type mentioned to increase reliability to improve. The solution to this is after an initial one Approach in a rising / low pressure casting process - especially of light metal alloys - as defined in claim 1.

After a second approach, a method is used to increase Casting / low pressure casting - especially of light metal alloys proposed as defined in claim 2.

A device suitable for carrying out these methods comprises a casting table with a passage opening, one below the casting table lying with a riser pipe, the one forms open mouth opening, a mold with a Base plate which has a downwardly open gate; the mouth opening seals against the passage opening from below scheduled, the casting mold with its pouring opening attached to the passage opening from above, means for horizontal displacement of the mold on the casting table and Means for maintaining a positive form at the same time the base of the mold opposite the casting table.

With the means specified herewith, a complete waiver possible on a slide lock, rather each for casting / mold filling the casting mold and the passage opening in the casting table or the mouth of the riser brought together and melt until Filled into the mold. Then after the first Approach the mold immediately after casting / mold filling still molten melt in the downwardly open gate the passage opening of the casting table or the mouth of the Riser pipe moved on the casting table so that the previously uniform Melting column in the riser pipe and in the sprue immediately and only by moving the casting mold opposite the passage opening in the casting table or the Mouth opening of the riser pipe is sheared off. As a closure act here the top of the casting table that with an inserted ceramic plate or rail can be reinforced, and the bottom of the base of the mold, which are flat on top of each other lie. In contrast, after the second approach after the Pouring / mold filling first waiting for the casting to solidify, until there is only liquid melt in the sprue, the then dropped back into the riser by lowering the pressure is before the emptied gate opposite the passage opening of the casting table or the mouth of the riser on the Casting table is moved so that the next mold is adjusted can be.

While in the first procedure an active printing task from above makes sense, in the second method, the pressure over the Melt generated in the riser.

To prevent the mold from floating when pouring, the surfaces mentioned can be pressed together with contact pressure become. This is made possible by elastic on the casting table attached horizontal rails or roller sets that are used for pressing the mold on the casting table when moving to fixed horizontal edges or rails of the mold act, or by means of horizontal rails arranged elastically on the casting mold or roller sets that are used to press the mold onto the casting table with horizontal edges fixed on the casting table or Interact rails. Suitable material pairings for this Surfaces are to be selected depending on the type of casting metal.

The supply of the molds in the casting position can be different Succeed, either using the mold each is placed on the casting table from above so that the passage opening or the mouth opening with the sprue opening is openly connected, or alternatively the casting mold in each case is fed horizontally over the casting table so that the passage opening or the mouth opening with the sprue opening is openly connected.

After pouring and moving the mold can be in one Position stopped in the casting table under the gate the mold is cooled. In addition to this the mold with the sprue when moving over a cooled section of the casting table. Through this Both measures will cause the melt to solidify rapidly Casting causes, after which the mold is not in the rest completed solidification from the casting table or the corresponding Funding can be withdrawn.

In the case of small, rapidly solidifying castings, it is convenient to have two Casting molds in tandem arrangement on a base plate with two Arrange sprue opening. Larger slower congealing Castings it is possible to provide a carousel arrangement, where several molds on a common base plate are constructed with a ring of gate openings.

Further advantageous embodiments of the method and more suitable Devices result from the subclaims which is hereby incorporated by reference.

So far from the rising casting / low pressure casting according to of the invention, the first relates to methods and devices in which the melt level in the sealed casting furnace a controllable gas pressure is given which causes the melt to rise or fall back in the riser. However, there are also other methods and devices included, which controllably promote the melt in the riser can, e.g. Magnetic pump arrangements at the lower end of the riser pipe in the casting furnace.

Figuren 1 bis 8

eine erfindungsgemäße Vorrichtung mit Gießtisch, Gießofen und zwei Gießformen, mit den einzelnen Phasen;

Figur 1

Aufbau eines Vordrucks im Gießofen; Form 1 in Gießposition; Form 2 ist geöffnet;

Figur 2

Abgießen der Form 1; Form 2 ist geschlossen;

Figur 3

Form 2 in Gießposition; Form 1 in Erstarrungsposition;

Figur 4

Abgießen der Form 2; Form 1 ist geöffnet;

Figur 5

Gießen der Form 2; Entformen der Form 1;

Figur 6

Form 1 in Gießposition; Form 2 in Erstarrungposition;

Figur 7

Abgießen der Form 1; Form 2 ist geöffnet;

Figur 8

Abgießen der Form 1; Entformen der Form 2;

Figur 9

eine erfindungsgemäße Gießanlage mit mehreren einzelnen Formen

a) in Draufsicht

b) in Seitenansicht;

Figur 10

eine erfindungsgemäße Gießanlage mit einem Schmelzofen, zwei Gießstationen und vier Gießöfen.

Preferred embodiments of the invention are described below with reference to the drawings. Here show the

Figures 1 to 8

an inventive device with casting table, casting furnace and two molds, with the individual phases;

Figure 1

Development of a form in the casting furnace; Form 1 in casting position; Form 2 is open;

Figure 2

Pouring of mold 1; Form 2 is closed;

Figure 3

Form 2 in casting position; Form 1 in the freezing position;

Figure 4

Pouring of mold 2; Form 1 is open;

Figure 5

Casting mold 2; Removal from mold 1;

Figure 6

Form 1 in casting position; Form 2 in the freezing position;

Figure 7

Pouring of mold 1; Form 2 is open;

Figure 8

Pouring of mold 1; Demoulding of form 2;

Figure 9

a casting plant according to the invention with several individual forms

a) in top view

b) in side view;

Figure 10

a casting plant according to the invention with a melting furnace, two casting stations and four casting furnaces.

Figures 1 to 8 are first described together, insofar the details match. A horizontal casting table 11 has a passage opening 12 with an outer Lining 13 and an inner lining 14 are sheathed is. Under the casting table 11 there is a casting furnace 21 which has a riser pipe 22 which is sealingly inserted into the casting furnace and below into the melt 23 contained therein dips and has an opening 24 at the top. Through a Arrow 25 indicates that compressed air is applied to the casting furnace 21 can be, so that a melt column 26 in the riser rises. There are two with the numbers on the casting table "1" and "2" designated molds that have a common base plate Have 30. This base plate 30 has sprue openings 31, 32 on, optionally by moving the base plate 30 can be made to coincide with the passage opening 12. The gate openings 31, 32 are each with linings 33, 34 provided. The molds built on the base plate 30 1, 2 each have brackets 35, 36, 37, 38 with actuating cylinders, 39, 40, 41, 42 on the mold halves 43, 44, 45, 46 act. Sits in the middle between the mold halves Central mandrel 47, 48, whose suspension is not shown in detail is. This forms together with the closed mold halves each a hollow cylinder with a slightly conical inner shape and external ribbing. That with the forms 1, 2 shown The cast part to be produced can be made in particular of a cylinder liner Be light metal for internal combustion engines. Changes in volume and shape of the casting when solidifying are in all representations neglected.

In the embodiment shown, the riser pipe 22 closes sealing against the bottom in the area of the passage opening 12 Casting table 11 on. This can be done with elastically suspended in the casting furnace 21 Riser 22 of the casting furnace 21 from below against the casting table 11 can be moved in height. The respective gate 31 32 in the base plate 30 is sealingly on the upper Exit of the passage opening 12 on.

Lowering the casting furnace is particularly advantageous in order to replace an empty pouring furnace with a full pouring furnace.

In Figure 1, a pre-pressure is built up in the casting furnace Melting column 26 to slightly above the mouth opening 24 lets rise. The mold 1 is the casting furnace 21 by moving the base plate 30 to the right in a first casting position assigned. The mold 1 is closed, as by arrows indicated and ready to pour. The mold 2 is open, as indicated by arrows and demolded.

In Figure 2, the form in the casting furnace 21 is increased so that the Melting column 26 has risen and the mold 1 completely is filled. The casting process as such has already ended here. The mold 2 is now closed as indicated by arrows shown.

In Figure 3, the base plate 30 is to the left in a second Casting position shifted, with the melt column in the mold 1 between the casting table 11 and base plate 30 has been sheared off and in the mold 1 a finished casting has been created. The Mold 2 is the casting furnace 21 by moving the base plate 30 assigned to the left in a second casting position and is in closed position ready for casting. The melt column 26 is at the mold 1 immediately after shearing in the riser 22 again up to slightly above the mouth opening 24 dropped behind.

In FIG. 4, the casting mold 1 is open as indicated by arrows, the finished casting still on the central mandrel 47 is held. In mold 2 is by increasing the pressure in the casting furnace the melt column has risen so that the mold is complete is filled. The actual casting process has already been completed here.

In Figure 5, the mold 1 is closed again, the finished casting 49 is completely removed from the mold. The mold 2 is as in Figure 4 shown during the melting process.

In Figure 6, the base plate 30 is right again in the first casting position shifted so that the mold 1 again Casting furnace 21 is assigned. The melting column in mold 2 is have been sheared, so that a finished in the mold Cast part is recognizable. The mold 2 is still closed to wait for the solidification process. The mold 1 is prepared to the next casting process, the melt column 26 slightly ends above the mouth opening 24 in the riser pipe 22.

In FIG. 7, the mold 2, as indicated by arrows, opened, with a finished casting still on the central pin 48 sits on. In the mold 1 is by increasing the form in the casting furnace 21, the melt column 26 increased and thus the filled so that the actual casting process already ends here is.

In Figure 8, the casting 50 is removed from the mold 2 and the mold is closed again for the next casting process. The casting mold 1 is in the corresponding position with FIG. 7 shown by moving the mold with the base plate the next moment, the melt column 26 between Base plate 30 and casting table 11 are sheared off.

FIG. 9 shows a casting table 51 with a passage opening 52 as well as with cooling positions 53, 54 indicated by arrows. Under the casting table is a casting furnace 61 with a Riser pipe 62, which is filled with melt. The mouth opening 64 of the riser pipe 62 closes the passage opening from below 52 on. There are three individual molds on the casting table 51 71, 72, 73 put on. The shape 71 lies with the sprue 74 the casting furnace 61 and is in the process of being poured. The Form 72 is already opposite the passage opening 52 shifted to the left, whereby the melt column has been sheared off and is in a position where the gate 75, 76 in the mold 72, 73 over a cooling area 53 of the casting table lies. The mold 73 is moved further, and is located in a position in which the gate 75, 76 in the mold 72, 73 lies over a cooling area 53, 54 of the casting table, wherein in Soot 76 has solidified. From here can the mold moved further or directly from the casting table be lifted off. The effect is shown by arrows 77, 78 of a form, which is indicated when filling the mold Leakage of melt prevented. By an arrow 79 is the Effect of a higher active pressure for feeding is displayed.

In Figure 10, a device according to the invention is in supervision shown, wherein a casting table 91 formed only as narrow paths is. The casting table here has two casting stations 92, 93 with openings 94, 95 and two solidification stations 96, 97. Casting molds 101, 102 can each be viewed from above Pouring stations for casting are placed, after the Pouring can be moved and then the positions of here adopt molds 103, 104 designated during solidification. Pouring furnaces ND1, ND2, ND3, ND4 can be close to one Brought furnace 111 and from there to a holding position in front of the casting stations 92, 93, in a casting position and in move to a stop position behind the casting stations 92, 93 so that each time empty pouring furnaces. at the melting furnace 111 be filled and immediately after emptying a casting furnace filled pouring furnace from a waiting position to the pouring position can be refilled under the casting table. At least one of the Casting stations 92, 93 of the casting table should always be ready for casting, so that no production interruption during the change a casting furnace. The two casting stations can Usually also run in parallel to the production rate to increase.

Claims (18)

1. A method for uphill/low-pressure casting, especially of light metal alloys,

   with a casting table having a flow-through opening,

   with a casting furnace lying below the casting table with a riser pipe forming an upwardly open mouth opening,

   with a mould having a base plate which has an downwardly open pouring-in opening,

   wherein

   the mouth opening is positioned against the flow-through opening in a sealing fashion from below,

   the mould and its pouring-in opening is brought over the flow-through opening,

   melt is conveyed from the casting furnace via the riser pipe into the mould until it is filled,
   communication between the casting furnace and the mould until the pouring-in opening is closed by the casting table below and the flow-through opening is closed by the base plate above, and

   the melt is allowed to drop in the riser pipe as far as below the mouth opening.
2. The method for uphill/low-pressure casting, especially of light metal alloys,

   with a casting table having a flow-through opening,

   with a casting furnace lying below the casting table with a riser pipe forming an upwardly open mouth opening,

   with a mould having a base plate which has a downwardly open pouring-in opening,

   wherein

   the mouth opening is positioned against the flow-through opening in a sealing fashion from below,

   the mould with its pouring-in opening is pushed over the flow-through opening,

   melt is conveyed from the casting furnace via the riser pipe into the mould until it is filled,

   the mould is left in this position until the casting has solidified and liquid melt is only still found in the sprue,

   the melt is allowed to drop in the riser pipe as far as below the mouth opening, and

   the mould is displaced horizontally on the casting table with its flow-through opening emptied of melt, until the pouring-in opening is closed by the casting table below and the mouth opening is closed by the base plate above.
3. The method according to one of Claims 1 or 2, wherein the mould is in each case placed on the casting table from above so that the flow-through opening or the mouth opening is in open communication with the pouring-in opening.
4. The method according to one of Claims 1 and 2, wherein the mould is in each case transferred horizontally over the casting table so that the flow-through opening or the mouth opening is in open communication with the pouring-in opening.
5. The method according to one of Claims 1 to 4, wherein during the uphill casting and the displacement of the mould, the mould is held under pre-pressure against the casting table or the riser pipe.
6. The method according to one of Claims 1 to 5, wherein during the uphill casting and the displacement of the mould, the riser pipe is held under pre-pressure against the casting table or the base plate of the mould.
7. The method according to one of Claims 1 or 3 to 6, wherein after the displacement of the mould, the mould is held in a position in which the casting table is cooled under the pouring-in opening.
8. The method according to one of Claims 1 or 3 to 7, wherein during displacement of the mould, the mould together with the pouring-in opening is guided over a section of the casting table which is cooled.
9. The method according to one of Claims 1 to 8, wherein two moulds are alternately mounted on a base plate with two pouring-in openings, cast and demoulded, wherein the base plate alternately with the pouring-in openings is displaced over the flow-through opening or onto the mouth opening.
10. The method according to one of Claims 1 to 8, wherein a plurality of moulds are sequentially mounted on a base plate with a ring of pouring-in openings, cast and demoulded, wherein the base plate is turned in a carousel fashion with the pouring-in openings over the flow-through opening or the mouth opening.
11. An apparatus for uphill casting/low-pressure casting, especially for casting light metal alloys, with a casting table with a flow-through opening,
    with a casting furnace lying below the casting table with a riser pipe, forming an upwardly open mouth opening,
    with a mould with a base plate having a downwardly open pouring-in opening;
    the mouth opening is positioned against the flow-through opening in a sealing fashion from below,
    the mould is positioned with its pouring-in opening against the flow-through opening from above,
    characterised by means for horizontal displacement of the mould on the casting table and means for simultaneously maintaining a positive pre-pressure of the mould base plate towards the casting table.
12. The apparatus according to Claim 11,
    characterised in that the mould has coolant above a non-cooled sprue region.
13. The apparatus according to one of Claims 11 or 12, characterised by horizontal rails or sets of rollers secured elastically to the casting table which act on fixed horizontal edges or rails of the mould to press the mould on the casting table during displacement.
14. The apparatus according to one of Claims 11 or 12, characterised by horizontal rails or sets of rollers arranged elastically on the mould which interact with horizontal edges or rails arranged securely on the casting table to press the mould on the casting table.
15. The apparatus according to one of Claims 11 to 14, characterised by means for pressing the riser pipe on the casting table or the mould.
16. The apparatus according to Claim 15, characterised by a riser pipe suspended elastically in the casting furnace and height adjustment means for the casting furnace.
17. The apparatus according to one of Claims 11 to 16, characterised by two moulds placed on a common base plate with two pouring-in openings, especially permanent moulds, as well as means of displacement for alternating displacement of the base plate.
18. The apparatus according to one of Claims 11 to 16, characterised by a plurality of moulds placed on a common base plate with a ring of pouring-in openings, especially permanent moulds, as well as rotating drive means for rotating drive of the base plate.

Images