Apparatus for Filling a Melt into a Casting Chamber, and Method for Filling Melt into a Casting Chamber

Abstract

An apparatus for introducing a melt into a casting chamber for a die casting operation has a tundish with an inner volume that can be filled with the melt. A method is provided for filling, by way of the apparatus, the melt into the casting chamber for the die casting operation.

Claims

1. An apparatus for filling a melt into a casting chamber for die casting, comprising: a tundish with an inner volume, wherein the inner volume is fillable with the melt, wherein the tundish is arrangeable in the casting chamber in a reversible manner over an inner surface of the casting chamber, the tundish has a pouring opening for filling the melt into the casting chamber, and the tundish has a closure body for opening and closing the pouring opening.

2. The apparatus as claimed in claim 1, wherein the tundish and/or the inner volume have a funnel-shape design.

3. The apparatus as claimed in claim 1, wherein the closure body is configured in the form of a valve body for opening and closing the pouring opening, and the valve body, in a first position, closes the pouring opening and, in a second position, opens the pouring opening.

4. The apparatus as claimed in claim 3, wherein the valve body has a contact protrusion which projects out of the tundish, and is configured for establishing contact with the inner surface of the casting chamber, wherein, by virtue of contact being established, the valve body is moved from its first position into its second position.

5. The apparatus as claimed in claim 4, wherein the contact protrusion projects out of the pouring opening of the tundish.

6. The apparatus as claimed in claim 3, further comprising: an elastic element whose force acts on the valve body in the direction of its first position.

7. The apparatus as claimed in claim 6, wherein the elastic element is a spring.

8. The apparatus as claimed in claim 3, wherein the valve body, at least in part, has a plug-shape, plate-shape or trough-shape design.

9. The apparatus as claimed in claim 8, wherein the valve body, at least in part, has an omega-trough-shape design.

10. The apparatus as claimed in claim 3, further comprising: a valve-seat ring arranged on the pouring opening, wherein the valve body has a contact cone for establishing contact with the valve-seat ring.

11. The apparatus as claimed in claim 10, wherein the contact cone has an angle of approximately 5 degrees for establishing contact with the valve-seat ring.

12. The apparatus as claimed in claim 3, wherein the valve body is mounted in a linearly movable manner in a bearing.

13. The apparatus as claimed in claim 1, wherein the tundish is fixed on a casting channel, wherein the tundish is fillable via the casting channel and is pivotable together with the casting channel in order to be arranged over the inner surface of the casting chamber.

14. The apparatus as claimed in claim 13, wherein the tundish and/or the casting channel are of closed design.

15. The apparatus as claimed in claim 14, wherein the tundish and/or the casting channel are fillable, or are filled, at least in part with an inert gas.

16. The apparatus as claimed in claim 1, wherein the tundish has an overflow opening for limiting a level of the melt in the inner volume.

17. A method for filling a melt into a casting chamber for die casting by an apparatus, wherein the apparatus has a tundish with an inner volume fillable with the melt, the tundish being arrangeable in the casting chamber in a reversible manner over an inner surface of the casting chamber and having a pouring opening for filling the melt into the casting chamber and a closure body for opening and closing the pouring opening, wherein the method comprises the acts of: a) filling the melt into an inner volume of the tundish of the apparatus; b) arranging the tundish over the inner surface of the casting chamber; c) opening the pouring opening of the tundish, for the purpose of filling the melt into the casting chamber, by way of the closure body of the tundish; d) filling the melt into the casting chamber; e) closing the pouring opening by way of the closure body; and f) moving the tundish away from the inner surface.

18. The method as claimed in claim 17, wherein in step a), a level of the melt in the inner volume is monitored, in order to determine a quantity of the melt in the inner volume, wherein deposits in the inner volume are taken into account during the operation of determining the quantity.

19. The method as claimed in claim 18, wherein the monitoring of the level of the melt in the inner volume is carried out by one or more of laser measuring, ultrasonic measuring or eddy-current measuring.

20. The method as claimed in claim 18, further comprising one or more of the following acts: a) heating the inner volume of the tundish and/or a casting channel, prior to step a), or b) cleaning the inner volume of the tundish prior to step a).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Elements having the same function and operation are provided with same reference signs in the individual figures in which, schematically:

[0037] FIGS. 1, 2 and 3 show a first embodiment of an apparatus according to the invention as it implements a method according to the invention.

[0038] FIGS. 4, 5 and 6 show a second embodiment of an apparatus according to the invention as it implements a method according to the invention.

[0039] FIG. 7 shows different embodiments of a valve body of an apparatus according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0040] FIGS. 1, 2 and 3 show a first embodiment of an apparatus 10 during different stages of a method according to the invention. FIGS. 1, 2 and 3 will therefore be described together hereinbelow, reference being made to individual figures wherever expedient and necessary. An apparatus 10 is designed for filling a melt 60 into a casting chamber 50. For this purpose, the apparatus 10 has a tundish 20. The tundish 20, furthermore, has an inner volume 26, which can be filled with the melt 60. A pouring opening 21 at the lower end of the tundish 20 is closed by way of a closure body 27, which in the present embodiment is designed in the form of a valve body 30 and, in FIGS. 1 and 2, is located in its first position 33. In particular, the valve body 30 has a contact cone 32, which is adapted to a valve-seat ring 22 of the pouring opening 21. Particularly good sealing of the inner volume 26 of the tundish 20 can thus be achieved, as a result of which the melt 60 can be reliably retained in the inner volume 26 when the pouring opening 21 is closed. A level 61 of the melt 60 in the inner volume 26 can be monitored here, for example by a laser-measuring method and/or ultrasonic-measuring method and/or an eddy-current method, in order to ensure a constant quantity of melt 60 in the inner volume 26. The tundish 20 here is of funnel-shape, that is to say in particular conical, design, as a result of which, in the case of an operation where the tundish 20 is arranged over an inner surface 51 of the casting chamber 50 and where the tundish 20 is introduced, at least in part, into the interior of the casting chamber 50 through a filling opening 52, it is easier for the tundish 20 to be introduced into the casting chamber 50 and it is also possible for the tundish 20 to undergo, for example, self-centering in the filling opening.

[0041] FIG. 2 shows the apparatus 10 in which the tundish 20 is shown during step b) of the method according to the invention, that is to say as the tundish 20 is being arranged over the inner surface 51 of the casting chamber 50. The figure depicts, in particular, that the valve body 30 has a contact protrusion 31, which is designed for establishing contact with the inner surface 51 of the casting chamber 50. As the tundish 20 is being lowered further into the casting chamber 50, the contact protrusion 31 prevents the valve body 30 from being lowered further together with the rest of the tundish 20. The valve body 30 is pushed upward relative to the tundish 20. As a result, the pouring opening 21 is freed automatically and thus opened. The melt 60 can then flow out of the inner volume 26, likewise of funnel-shaped design, into the casting chamber 50.

[0042] The possibility of arranging the tundish 20 over the inner surface 51 of the casting chamber 20 means that a drop height of the melt 60 from the pouring opening 21 of the tundish 20 onto the inner surface 51 of the casting chamber 50 is small, in particular preferably smaller than approximately 1 cm. This makes it possible to avoid erosion on the inner surface 51, which could be caused by the melt 60 impacting at high speed on the inner surface 51.

[0043] FIG. 3 shows the apparatus 10 which is arranged entirely in its definitive position over the inner surface 51 of the casting chamber 50. The contact established by the contact protrusion 31 has pushed the valve body 30 back into the interior of the inner volume 26 of the tundish 20. The pouring opening 21 is open and the melt 60 has already flowed out of the tundish 20 into the casting chamber 50. When the tundish 20 moves upwards, and thus out of the casting chamber 50, the valve body 30 is moved back out of its second position 34, which is shown in FIG. 3, into its first position 33 (see FIGS. 1 and 2), for example merely under the action of the force of gravity. Once the tundish 20 has been removed from the casting chamber 50, a melt 60 located in the casting chamber 50 can be shot into a mold (not included in the figure) by a plunger (not included in the figure), in order for the die-casting operation to be completed. During this operation of the melt 60 being shot in, and/or as the die-casting operation continues, it is already possible for melt 60 to be filled anew into the inner volume 26 of the tundish 20, and this makes it possible to achieve, in particular, a good cycle time for the die-casting operations. Overall, an apparatus 10 according to the invention can thus be achieved such that, on the one hand by virtue of the quantity of melt 60 in the inner volume 26 being monitored, it is possible to ensure a constant filling of the casting chamber 50 with melt 60 and, on the other hand, by virtue of the small drop height of the melt 60 between the pouring opening 21 and the inner surface 51, it is also possible to avoid damage to the casting chamber 50. This makes it possible to cut back overall on costs and time required for carrying out die-casting operations.

[0044] FIGS. 4, 5 and 6 show a further possible embodiment of an apparatus 10, in particular FIGS. 1 and 4, FIGS. 2 and 5 and FIGS. 3 and 6 showing in each case the same point in time of a method according to the invention. All the advantages which have been described in relation to that embodiment of an apparatus according to the invention which is described in FIGS. 1, 2 and 3 thus also apply analogously to those embodiments of an apparatus according to the invention which are described in FIGS. 4, 5 and 6. The following text will therefore deal, in particular, with the differences between the two embodiments. Therefore, for example the embodiment of an apparatus according to the invention which is shown in FIGS. 4, 5 and 6 has a casting channel 24, which is fixed to the tundish 20. As a result, all that is required for arranging the tundish 20 over the inner surface 51 of the casting chamber 50 is a straightforward, joint pivoting movement of the tundish 20 and of the casting channel 24. Such a pivoting movement can be effected, for example, by a shaft with a protuberance (not included in the figure), which acts on the casting channel 24.

[0045] Furthermore, the tundish 20 is provided with a cover 28. Energy losses, for example as a result of thermal radiation, from the melt 60 can be reduced, or even avoided altogether, by said cover 28. It is thus possible, for example, to ensure that the melt 60 in the inner volume 26 of the tundish 20 remains liquid throughout the course of the method being implemented. Furthermore, the cover 28 contains a sensor 11, which is designed for monitoring a level 61 of the melt 60 in the inner volume 26 of the tundish 20. This can ensure that a constant quantity of melt 60 is located in the inner volume 26 whenever the method is being implemented.

[0046] Furthermore, the tundish 20 depicted has an overflow opening 25. In the event of the sensor 11 failing, melt 60, when the level 61 rises above the height of the overflow opening 25, can flow out of the tundish 20 through said overflow opening. It is thus also the case here that a constant quantity of melt 60 can be ensured in the inner volume 26. Overfilling of the casting chamber 50 with too much melt 60 can thus be reliably avoided.

[0047] FIGS. 4, 5 and 6 also show a bearing 23, in which the valve body 30 is mounted in a linearly movable manner. An elastic element 40, in particular a spring 41, pushes the valve body 30 in the direction of its first position 33. This can ensure that the pouring opening 21 is reliably closed by contact being established between the contact cone 32 and the valve-seat ring 22. It is only when the contact protrusion 31 establishes contact with the inner surface 51 of the casting chamber 50 that the valve body 30 is pushed, counter to the force of the spring 41, into the interior of the inner volume 26 and the pouring opening 21 is opened as a result, see FIG. 6. In the case of the tundish 20 then being removed from the casting chamber 50, the spring 41 automatically displaces the valve body 30 back into its first position 33, in which the pouring opening 21 is closed by way of the valve body 30.

[0048] FIG. 7 shows three different embodiments of a closure body 27 of an apparatus 10 according to the invention. Each closure body 27 here is designed in the form of a valve body 30. A respective contact protrusion 31 is arranged at the end of the valve body 30 and is designed for establishing contact with an inner surface 51 of a casting chamber 50 (not included in the figure). The valve bodies 30 also each have a contact cone 32, which is designed for establishing contact with a valve-seat ring 22 of the pouring opening 21 in the tundish 20 (not included in the figure) and is also adapted to said valve-seat ring. Particularly tight closure of the pouring opening 21 (not included in the figure) can be achieved as a result.

[0049] The three valve bodies 30 shown differ in shape, and this means that the behavior of melt 60 flowing out of the apparatus 10 according to the invention changes in each case. Thus, the left-hand valve body 30 is of plug-shape design. A particularly laminar outflow of the melt 60 from the pouring opening 21 can be achieved as a result.

[0050] The central valve body depicted in the middle is of plate-shape design at its lower end. Since the plate-shape formation is arranged between the contact cone and the contact protrusion, said plate-shape formation is located outside the inner volume 26 when the valve body 30 is arranged in an apparatus 10 according to the invention. When the melt 60 flows out of the inner volume 26, it comes into contact with the plate-shape formation and is thus discharged radially, and therefore concentrically, into the casting chamber 50 (not included in the figure). This makes it possible to avoid the situation, in particular, where the melt 60 impacts on the inner surface 51 of the casting chamber 50 at certain points.

[0051] The valve body 30 depicted on the right has a trough-shape formation at its lower end. It is also the case that this trough-shape formation is arranged outside the inner volume 26 when an apparatus 10 according to the invention is in its assembled state. Such a trough at the end of the valve body 30 can avoid, in particular, the situation where the melt 60 sloshes as it is being filled into the casting chamber 50. Provision may preferably be made here for the trough to be of omega-shape design. Omega-shape here means that the trough is open in the direction of one side. This means that the melt 60, as it is being filled into the casting chamber 50, flows out preferably in the direction of the opening in the trough, and this makes it possible to have a preferred direction when the casting chamber 50 is being filled. This may be advantageous in particular in the case of elongate casting chambers 50.

LIST OF REFERENCE SIGNS

[0052] 10 apparatus [0053] 11 sensor [0054] 20 tundish [0055] 21 pouring opening [0056] 22 valve-seat ring [0057] 23 bearing means [0058] 24 casting channel [0059] 25 overflow opening [0060] 26 inner volume [0061] 27 closure body [0062] 28 cover [0063] 30 valve body [0064] 31 contact protrusion [0065] 32 contact cone [0066] 33 first position [0067] 34 second position [0068] 40 elastic element [0069] 41 spring [0070] 50 casting chamber [0071] 51 inner surface [0072] 52 filling opening [0073] 60 melt [0074] 61 level of the melt

[0075] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.