WO2013180570A1

WO2013180570A1 - Transport device for a casting unit

Info

Publication number: WO2013180570A1
Application number: PCT/NL2013/050392
Authority: WO
Inventors: Peter HOEDEMAKERS
Original assignee: Gemco Engineers B.V.
Priority date: 2012-05-31
Filing date: 2013-05-31
Publication date: 2013-12-05
Also published as: NL2008908C2

Abstract

The invention relates to a transport device for a casting unit with an outlet opening for casting a casting material, such as liquid metal, in a casting direction under the influence of gravitational force. The transport device comprises a frame and support means connected thereto for the casting unit. The transport device is provided with transport means for displacing the frame with the support means in a transport direction that is substantially at right angles to the casting direction. According to the invention, the support means are provided with a bearing surface on which the casting unit can be placed for supporting the casting unit during casting of the casting material.

Description

Title: Transport device for a casting unit

Description

The invention relates to a transport device for a casting unit with an outlet opening for casting a casting material, such as a liquid metal, in a casting direction under the influence of gravitational force, said transport device comprising a frame and support means connected thereto for the casting unit, wherein the transport device is provided with transport means for displacing the frame with the support means in a transport direction that is substantially at right angles to the casting direction.

Casting ladles with bottom outlets are used in (steel) foundries for the casting of metal. A transport device in the form of an overhead crane is used for positioning the casting ladle with its outlet opening above the mould. This is an accurate and hazardous job. The operator must stand close to the casting ladle in order to be able to judge whether the ladle is correctly positioned above the inlet opening and to stabilize the ladle so as to counteract any rocking or rotary movements of the ladle.

It is accordingly an object of the present invention to provide a device with which the casting unit can be positioned above the mould in a safer and simpler manner. It is especially an object of the present invention to provide a transport device for a casting unit that is in addition comparatively efficient.

To achieve this object, the invention provides a transport device of the kind mentioned in the opening paragraph which is characterised in that the support means are provided with a bearing surface on which the casting unit can be placed for supporting the casting unit during casting at the casting material.

A stable placement is made possible in that the casting unit can be placed with its bottom on the bearing surface of the transport device. Rocking and rotary movements of the ladle are prevented thereby. A relative movement between the casting unit and the frame of the transport device is prevented. The casting unit can be placed on the transport device in a stable manner. After the casting unit has been positioned, it has become (at least substantially) impossible for it to move freely relative to the frame. The disadvantages of the prior art transport device, in which uncontrolled rocking or rotary movements can occur owing to the use of an overhead crane and a cable, are not present in the transport device according to the present invention. This makes a more efficient casting process possible because the operator does not need to stand close to the ladle any more in order to counteract rocking and rotary movements of the ladle. The transport means at the same time ensure that an accurate positioning of the casting unit above the mould is made possible. The object of the present invention is thus achieved.

The frame is preferably provided with pillars. These pillars are preferably connected to the solid world in a displaceable manner. A conceivable connection is one with a guide against the ceiling or wall of a space and/or a building in which the casting process takes place. A connection to a floor of the solid world, however, is preferred here because the casting device can then be used in a comparatively flexible manner while in addition a comparatively large displacement is made possible in a simple and inexpensive manner.

In an embodiment that is connected to the floor, the frame is preferably provided with pillars that extend away from the frame with a component in the (positive) casting direction. Said pillars are then placed on the floor in a displaceable manner, for example through the use of wheels or rails. The support means are located at a distance from the floor. One or more moulds can be placed between the support means and the floor. The transport device can then be positioned such that the casting unit is present with its outlet opening above the inlet opening. A lead-through passage of the support means will then be present between the outlet opening and the inlet opening such that the casting material can be poured without obstructions into the mould in a safe and simple manner.

A simple and inexpensive construction is obtained when the pillars comprise the transport means. It is preferred, especially when the pillars are placed on a floor, that the transport means are arranged adjacent that end of each respective pillar that is remote from the frame.

It is preferred in order to enhance the accuracy of the transport device for the casting unit still further that the support means are connected to the frame so as to be displaceable relative thereto. This renders possible a further refinement of the positioning of the casting unit relative to the inlet opening of the mould.

It is particularly preferred in this case that the support means are displaceable in a direction that is substantially at right angles to the casting direction and substantially at right angles to the transport direction. It becomes possible thereby to position the outlet opening of the casting unit within a plane. Said plane extends substantially parallel to the floor of the solid world.

The control of the displacement in the transport direction is preferably independent of the control of the displacement of the support means in the direction mentioned above. The use of the frame renders an accurate positioning in the plane possible, while rocking and rotary movements such as they occur with the prior art overhead cranes are counteracted.

A still further increase in the accuracy of the transport device is obtained in that the support means are vertically adjustable. This has the result that the outlet opening of the casting unit can be brought to a desired (maximum) distance to the inlet opening of the mould. This leads to a minimum cooling down of the molten material during the casting process so that a casting product of comparatively good quality is obtained.

The three displacement possibilities in the transport direction, in a direction perpendicular thereto and perpendicular to the casting direction, and in a vertical direction (substantially parallel to the casting direction) as described above provide an accurate placement possibility in a Cartesian system of coordinates. Each individual displacement possibility is substantially perpendicular to the other two displacement possibilities. This makes for a greater accuracy and enhances the ease with which the positioning can be carried out, in particular in comparison with the known system with an overhead crane and a suspension hook, in which such an accurate positioning is relatively difficult because the individual displacements cannot (or substantially not) be carried out independently of one another.

A particularly simple construction as regards the vertical adjustment of the support means is obtained when the pillars, if used, are vertically adjustable. The pillars may be telescopically constructed. A vertical adjustment may then be effected in a simple manner, for example by pneumatic means.

The displacement of the transport device may be effected in a comparatively energy-efficient manner in that the transport means comprise a number of rotatable members. These may be, for example, wheels.

In a preferred embodiment, one or more rotatable transport members are used that are accommodated in guide rails. Rails are provided at the casting location, for example comparable to those of a railway or tramway track, in an embodiment. The rotatable transport member is then constructed as a wheel that can move over the rail like the wheel of a train or tram. The use of the guide rails ensures that a displacement is made possible in the transport direction only.

To achieve a correct positioning of the outlet opening of the casting unit in an accurate manner, it is preferred that the transport device is provided with detection means for detecting an inlet opening in a mould for receiving the casting material. The transport device can then be brought into the correct position on the basis of the data thus obtained.

The transport device is preferably provided with drive means for driving the transport means so as to displace the transport device. The drive means are preferably also designed for driving the support means so as to displace the latter relative to the frame.

The transport device described above renders it possible to automate the casting process, in which a number of moulds are filled with liquid material, through a detection of the inlet openings and a correct positioning of the casting unit relative to the inlet openings. It will be obvious to those skilled in the art, however, that a manual displacement is equally possible within the scope of the invention.

In a preferred embodiment in which an automated casting process is possible, the detection means are designed for detecting the position of the inlet opening, and the transport device comprises control means for controlling the drive means on the basis of the detected position so as to align the inlet opening with the outlet opening of the casting unit. After this alignment the outlet opening may be opened, possibly after a check carried out by the operator.

The detection means preferably comprise one or more sensor members. These are preferably image sensors which are capable of detecting an image provided on a mould and containing information on the position of the inlet opening. An image processing unit may be provided for determining the position of the inlet opening on the basis of the detected images.

In a special embodiment, the detection means are designed for detecting a marker provided on the mould, such as a code, in particular a QR code. The QR code also renders it possible to provide, and possibly to store, additional information about the casting process or the product to be cast.

It is preferred that the support means comprise a weighing system for measuring the weight of the casting unit. Such a weighing system at the same time renders it possible to ascertain with accuracy the quantity of cast material in a casting. It thus becomes possible to control the casting process on the basis of the quantity of casting material that has flown out.

In a preferred embodiment, the casting unit can be placed on and removed from the transport device. Placing on the transport device may be effected with a known lifting device such as a tackle system. To simplify the placement, the support means preferably comprise a guide system for positioning the outlet opening of the casting unit on the bearing surface.

According to an aspect of the invention, the latter provides a casting device comprising a transport device according to an embodiment of the invention as described above as well as a casting unit placed on the support means and having an outlet opening for casting a casting material, such as a liquid metal, in a casting direction under the influence of gravitational force, said casting unit being placed on the bearing surface.

The advantages of such a casting device have been described above. In an embodiment, the casting unit is a so-termed stopper ladle.

The invention in one of its aspects also relates to the use of a casting device according to the invention. The invention will now be explained in more detail by means of a description of a preferred embodiment which is given with reference to the accompanying figures, in which:

Figures 1 a to 1 c present elevations of a transport device with a casting unit according to the invention;

Figures 2a and 2b are side elevations of the transport device in a low position and a high position, respectively;

Figures 3a to 3c are front elevations of the transport device during a (semi-) automatic casting process; and

Figure 4 is a plan view of the transport device during operation in a casting installation.

Figure 1 a shows a transport device 1 according to the invention designed for transporting a casting unit 2 which is known per se. The casting unit 2 comprises a holder 23 for the material 22 that is to be cast such as, for example, molten metal. In the bottom of the holder 23 there is an outlet opening 21 for the material 22 to be cast. A closing mechanism 25 is provided for opening and closing the outlet opening 21. When the outlet opening 21 is opened, the material 22 will flow in the casting direction G under the influence of gravity. Such a casting unit 2 is generally known as a so-termed stopper ladle.

The transport unit 1 according to the invention comprises a frame 4 with two parallel cross-beams 1 1 , as can be seen more clearly in figure 1 b. Support means 6 are provided between the two cross-beams 1 1 . Said support means comprise a bearing surface 61. The casting unit 2 can be placed on this bearing surface 61. A bottom of the holder 23 of the casting unit 2 has its seat on the bearing surface 61 . The bearing surface defines a circumference of a lead-through passage through which the casting material 22 can be passed such that it will fill a mould placed at the lower side of the casting unit 2. This will be explained in more detail further below.

The support means 6 are connected to the cross-beams in a displaceable manner by means of transport elements 19 shown in figure 1 b, for example in the form of guide wheels 19. A displacement in a lateral direction T2 is made possible thereby. The guide wheels 19 may be accommodated in a guide unit provided on the cross-beams 1 1 , such as guide rails. The use of four transport elements 18 incorporated in the cross-beams 1 1 ensures that the support means can be moved relative to the cross-beams 1 1 in the lateral direction T2 only and that relative movements in other directions are limited.

It is apparent from figure 1 a that a cross-beam 1 1 is fastened to a pillar 12. The pillar 12 extends substantially at right angles to the cross-beam. Each cross-beam 1 1 is provided with a pillar 12 at each of its two extremities. An assembly of one cross-beam 1 1 and two pillars 12 thus constitutes a U-shaped arc. The total of two such assemblies is arranged such that they are mutually parallel and at a distance to one another. At their lower sides the pillars of the two assemblies are interconnected via respective horizontal support beams 13.

This horizontal support beam 13 is clearly visible in figure 1 c. The horizontal support beam 13 is substantially at right angles to the pillars 12. Transport means 18 are provided on the horizontal support beams 13 (two in total), by means of which the entire transport device 1 can be displaced in the transport direction T1 . The transport means 18 are preferably guide wheels that fit in guide rails provided in the bottom B. Said transport direction T1 (forward direction) is substantially at right angles to the casting direction G and also at right angles to the lateral direction T2.

As can be seen from the figures 2a and 2b, the pillars 12 are adjustable in height between a small height (figure 2a) and a great height (figure 2b). Vertical adjustment means 14 are provided for this. The pillars are telescopically constructed with a first part 12 and a second part 12' that can be telescopically moved within the first part 12. A movement of the support means 6 in a vertical direction T3 is made possible thereby. The vertical direction is parallel to the casting direction G. The telescopic adjustment of the pillars is effected by hydraulically operating vertical adjustment means 14 in this embodiment. The support means 6 can be set at a desired level thereby.

The directions T1 , T2 and T3 thus constitute an orthogonal system. This renders it comparatively simple to manoeuvre the outlet opening 21 into a desired position. It also achieves that an automatic positioning becomes possible. Figure 3a shows that detection means 31 are provided for this purpose. The detection means 31 are capable of detecting the position of the inlet opening 51 , 61 of a mould 50, 60. The detection means 31 may comprise a camera with an image processor for processing images obtained by the image camera. Those skilled in the art of image detection and image processing will be able to implement suitable detection means 31 .

In a simple embodiment, a marker with a well detectable image is placed on the inlet opening. This may be, for example, a "crash test dummy marker", i.e. one having a geometric shape (for example square, circular) that is subdivided into (for example) four equal surface areas such that adjoining surface areas have contrasting colours (for example white-black, or yellow-black). Placement of the marker on the inlet opening renders it easy to determine the location of the inlet opening. If it is made of paper or cardboard, the marker will immediately disappear in the casting process owing to the high temperature without adverse effects on the casting product. The marker may be provided on a beaker-shaped holder which is designed to be partly accommodated inside the inlet opening.

The position of the inlet opening can be ascertained by the detection means, the image processing unit, and the markers used. The transport device 1 is brought into the correct position through displacements in the transport direction T1 and the lateral direction T2. In addition to the position thus obtained, the height of the inlet opening 51 , 61 may also be determined in the sense that a distinction is made between a high mould 60 and a low mould 50. The transport device may be lowered in dependence on the mould to be filled (figure 3b) or be kept at its original level (figure 3c).

The transport device may comprise drive means, which are not shown in any detail, for displacing the transport device in the transport direction T1 and for displacing the support means 6 in the lateral direction 12 and in the vertical direction T3. A control unit connected to the drive means can utilize the information obtained by the detection means and the image processing unit for positioning the transport device 1 in a (semi-) automatic manner. The casting unit 2 can subsequently be triggered so as to start the casting process in that the outlet opening 21 is released.

Figure 4 shows a casting installation comprising two rows I, I I of moulds 8a-8k extending side by side, each mould having a respective inlet opening 9a-9k. It can be seen that the inlet openings 9a-9k are more or less arbitrarily positioned. No regular pattern can be distinguished. The moulds 8a-8k can be filled in a simple manner, and even automatically, by means of the casting device 1 according to the present invention. The detection means are capable of detecting the inlet opening 9a of the mould 8a, whereupon the outlet opening 21 of the casting unit 2 can be positioned above the inlet opening 9a through a displacement of the transport device 1 in the transport direction T1 , a displacement of the support means 6 in the lateral direction T2, and a displacement of the support means 6 in the vertical direction T3. It is preferred in the embodiment shown in figure 4 that a column of moulds is filled each time. When the last mould of the column has been filled, a switch is made to the next column without changing the row I , I I. Thus all columns are processed. This means for the embodiment shown in figure 4 that mould 8a is filled first, then mould 8b (first column). The device then stays in row I I but jumps to the second column, filling mould 8c. Then mould 8d in the same column is filled. All moulds 8a-8k are thus dealt with in alphabetical order. It was found that such a displacement procedure is an effective one for the casting unit 2.

The casting unit 2 is taken from the transport device after the casting process has been completed. The moulds are removed and new moulds are put in place. A next casting unit with fresh casting material is placed on the transport device. The casting process can then be started anew. It will be clear to those skilled in the art that the invention was described above with reference to a few preferred embodiments. The invention, however, is by no means limited to these embodiments. Many equivalent modifications are conceivable within the scope of the invention which may very well be covered by the protection of the appended claims.

Claims

1. A transport device (1) for a casting unit (2) with an outlet opening (21 ) for casting a casting material (23), such as a liquid metal, in a casting direction (G) under the influence of gravitational force, said transport device (1) comprising a frame (4) and support means (6) connected thereto for the casting unit, wherein the transport device is provided with transport means (18) for displacing the frame (4) with the support means (6) in a transport direction (T1) that is substantially at right angles to the casting direction (G), characterised in that the support means (6) are provided with a bearing surface (61 ) on which the casting unit (2) can be placed for supporting the casting unit (2) during casting of the casting material.

2. A transport device according to claim 1 , wherein the frame (4) is provided with pillars (12) that extend with a directional component in the casting direction, and wherein the pillars (12) are provided with the transport means (13, 18) at a side facing away from the frame.

3. A transport device according to claim 2, wherein the pillars are connected to a floor (B) of the solid world at least during use of the device.

4. A transport device according to any one or more of the preceding claims, wherein the support means (6) are connected to the frame (4) so as to be displaceable relative thereto.

5. A transport device according to claim 4, wherein the support means (6) are displaceable in a direction (T2) that is substantially at right angles to the casting direction (G) and substantially at right angles to the transport direction (T1 ).

6. A transport device according to any one or more of the preceding claims, wherein the support means (6) are vertically adjustable.

7. A transport device according to claim 6 and claim 2, wherein the pillars (12) are vertically adjustable.

8. A transport device according to any one or more of the preceding claims, wherein the transport means (18) comprise a number of rotatable transport members (18).

9. A transport device according to claim 8, wherein the rotatable transport member (18) can be accommodated in a guide rail.

10. A transport device according to any one or more of the preceding claims, wherein the transport device is provided with detection means (31 ) for detecting an inlet opening (9a-9k) in a mould (8a-8k) for receiving the casting material (23).

1 1. A transport device according to any one or more of the preceding claims, wherein the transport device is provided with drive means for driving the transport means (18) so as to displace the transport device.

12. A transport device according to claim 5 and claim 1 1 , wherein the drive means are designed for driving the support means (6) so as to displace the latter relative to the frame (4).

13. A transport device according to claim 10 and at least one of the claims 1 1 and 12, wherein the detection means (31 ) are designed for detecting the position of the inlet opening (9a-9k), and wherein the transport device comprises control means for controlling the drive means on the basis of the detected position so as to align the inlet opening (9a-9k) with the outlet opening (21) of the casting unit.

14. A transport device according to claim 10 or claim 13, wherein the detection means (31 ) comprise one or more sensor members.

15. A transport device according to claim 10 or a claim dependent thereon, wherein the detection means (31 ) are designed for detecting a marker provided on the mould, such as a code, in particular a QR code.

16. A transport device according to any one or more of the preceding claims, wherein the support means (6) comprise a weighing system for measuring the weight of the casting unit.

17. A transport device according to any one or more of the preceding claims, wherein the support means (6) comprise a guide system for positioning the casting unit on the bearing surface.

18. A casting device comprising a transport device (1) according to any one of the preceding claims as well as a casting unit (2) that is placed on the support means (6) and that has an outlet opening (21 ) for casting a casting material (23), such as a liquid metal, in a casting direction (G) under the influence of gravitational force, wherein said casting unit (2) is placed on the bearing surface (61 ).

19. A casting device according to claim 18, wherein the casting unit (2) is a stopper ladle.

20. The use of a casting device according to claim 18 or 19.