US3822738A

US3822738A - Apparatus for guiding an oscillating continuous casting mold at a continuous casting installation with curved path of travel of the strand

Info

Publication number: US3822738A
Application number: US00328408A
Authority: US
Inventors: A Rotarides; W Bruderer
Original assignee: Concast AG
Current assignee: SMS Concast AG
Priority date: 1972-02-01
Filing date: 1973-01-31
Publication date: 1974-07-09
Anticipated expiration: 1991-07-09
Also published as: FR2170159B1; NL150702B; DE2304845B2; ZA73530B; AU468917B2; IT978648B; AR197395A1; AU5169273A; DE2304845A1; JPS525294B2; LU66937A1; DK129218C; CA977931A; BR7300758D0; JPS4884036A; FR2170159A1; DK129218B; NL7301440A; BE794852A; CH548243A

Abstract

An apparatus for guiding an oscillating or reciprocating continuous casting mold at a continuous casting installation having a curved axis of the path of travel of the strand, by means of a hinge or linkage mechanism equipped with at least four elements, wherein one element with a respective hinge at the ends thereof is formed by a mold arrangement which may be the mold itself or the mold and an extension thereof and another element serving as a frame is formed by a part of the structure of the installation. The paths of movement of the hinges are curved at the mold opposite to the axis of the path of travel of the strand.

Description

United States Patent Rotarides et al.

[11] 3,822,738 1 July 9,1974

3,395,751 8/1968 Hess 164/260 3,528,483 9/1970 Mallener 3,664,409 5/ I972 Kolomeitsev et al. 164/260 Primary Examiner-Charles W. Lanham Assistant Examiner-D. C. Reiley, Ill

[75 Inventors: ggg 'g gq iggiz; g gyzfi Attorney, Agent, or Firm-Werner W. Kleeman Feldmeilen, Switzerland I [73] Assignee: Concast AG, Zurich, Switzerland [57] ABSTRACT 22 Filed; Jam 31 973 An apparatus for guiding 3.11:1 oscillating or reciprocatmg continuous casting mo at a continuous casting [21] Appl. No.. 328,408 installation having a curved axis of the path of travel of the strand, by means of a hinge or linkage mecha- [30] Foreign A li ti priority m nism equipped with at least four elements, wherein Feb l 1972 Switzerland 1466/72 one element with a respective hinge at the ends thereof is formed by a mold arrangement which may [52] U 8 Cl 164/260 64/83 be the mold itself or the mold and an extension [51] B22d 11/00 thereof and another element serving as a frame is formed y a p of the Structure of the installation. [58] Field of Search 164/83, 260, 273 R The paths of movement of the hinges are curved at the [56] References Cited mold opposite to the axis of the path of travel of the UNITED STATES PATENTS 3,343,592 9/1967 Vogel 164/260 13 Claims, 3 Drawing Figures 4 a t x 2 i :1 5 s m L APPARATUS FOR GUIDING AN OSCILLATING CONTINUOUS CASTING MOLD AT A CONTINUOUS CASTING INSTALLATION WITH CURVED PATH OF TRAVEL OF THE STRAND BACKGROUND OF THE INVENTION The present invention relates to a new and improved apparatus for guiding an oscillating or reciprocatory continuous casting mold at a continuous casting installation or plant having a curved axis of the path of travel of the strand, by means of a hinge or linkage mechanism having at least four elements, wherein one element, equipped with a respective hinge at the ends thereof, is formed by a mold arrangement which may be the mold itself or such mold and an extension thereof, and another element serving as a frame is formed by a part of the structure of the installation.

lt is known during the casting of steel to oscillate or reciprocate continuous casting molds having arcor circular-shaped hollow mold cavities about a central position, in that the mold is guided at a short link or lever and additionally at a further short link or lever or at a guide mechanism. The short lever is connected at one end with the mold and at the other end with the stationary frame and extends from the mold in the direction of the center of the circular are which forms the center of curvature of the hollow mold cavity. With this arrangement the circular arc and the path of travel of the lever end connected with the mold are curved at the same side. The length of the lever is less than the radius of the curved axis of the path of travel of the strand and the extension of the lever axis should intersect a straight line interconnecting the center point of the hollow mold cavity and the center of the circular are at a predetermined point.

It is also known in the art to employ for molds having a straight hollow compartment or cavity and followed by a curved path of travel of the strand, instead of the lever or linkage arrangement, guides in the form of sliding blocks and rollers. These guides are arranged in such a manner that the linear mold walls, during the reciprocatory stroke, form at random points tangents at the circular arcs of the strand. Consequently, the mold moves along a circular arc, the center of which coincides with the center of the arc of the strand path of travel.

With these known proposals as heretofore advanced in the art there is assumed that the path of movement of the mold coincides as closely as possible with the desired axis of the path of travel of the strand, that is to say, the path of travel of the mold and the arc of the strand are curved at the same side so that the deviations caused by the smaller arc of the oscillatory movement do not produce any metallurgical drawbacks for the cast product. However, such type equipment is associated with decisive disadvantages.

With the heretofore proposed solution employing at least one short link or lever which extends in the direction of the center of the circular are which forms the center line of the hollow mold cavity, the bearing locations as well as the drive mechanism for the oscillatory movement must be arranged at the inner region of such circle. When working with small radii the space available at the inner region of the arc is very limited, as a result of which the mounting of the oscillatory unit oftentimes is associated with extensive difficulties. Additionally, the heat which is generated bythe cast strand at the inner arc cannot be as readily removed as the heat which is present at the outer arc. This in turn produces considerable deviations in the lever bearing locations owing to thermal expansion. Consequently, displacements arise between the mold and the following strand path of travel which, in turn, produce the familiar casting defects, such as for instance, the formation of fissures or cracks at the cast strand. ln the case of installations having adjustable molds there arise still further difficulties since, in the normal situation, the mold wall directed toward the center of the strand arc is displaceable. In such installations the strand guide arrangement following the mold is also adjustable. The means necessary for the adjustment operations are likewise arranged at the side of the strand guide arrangement which is directed towards the center of the arc of the strand. Mounting of the adjustment elements for the mold, the strand guide arrangement and the oscillation mechanism at the same side of the strand path of travel results in constructional drawbacks which only can be overcome with great difficulty.

Guiding of the mold by means of sliding blocks and rollers has the drawback that, owing to the large horizontal forces, these guides tend to wear quite rapidly, so that the mold no longer follows the desired path. This shortcoming can only then be overcome by performing extensive maintenance operations and expending an excessive amount of time for readjusting such guides. In actual practice, it has been found that guiding of the mold in a manner that the linear mold walls form tangents at the desired path of travel of the strand at each point of the oscillatory movement does not really produce any satisfactory casting results.

SUMMARY OF THE INVENTION Hence, this particular field of technology is still in need of improved apparatus for guiding an oscillatory or reciprocatory continuous casting mold at a continuous casting plant having a curved path of travel of the strand in a manner not associated with the aforementioned drawbacks and limitations of the prior art proposals. Thus, it is a primary object of the present invention to provide an improved apparatus of the aforementioned type which effectively and reliably fulfills the needs still existing in the art and is not associated with the aforementioned drawbacks and limitations of the prior art proposals.

Another and more specific object of the present invention relates to a new and improved construction of apparatus which allows oscillating or reciprocating a continuous casing mold by means of short levers without having to take into account any appreciable disadvantages with respect to the quality of the cast product.

It is another object of the present invention to provide an improved apparatus of the aforementioned type wherein other parts of the installation are not obstructed and there is achieved better accessibility with respect to the adjustment mechanisms.

Now in order to implement these and still further objects of the invention, which will become more readily apparent as the. description proceeds, the invention contemplates that the paths of movement of the hinges or pivot points at the mold are curved opposite to the axis of the path of travel of the strand.

The apparatus of this development enables arranging the oscillation lever and the oscillation drive at the outside of the curved axis of the path of travel of the strand, so that the oscillation device can be accommodated at a region which is subjected to lower thermal loads and no longer hinders the adjustability of the adjustable mold. Additionally, the accessibility to the uppermost portion of the strand guide arrangement is considerably improved and the maintenance of the oscillation device is considerably facilitated since more space is available at the outside.

In the case of installations where the axis of the hol low moldingand guide cavity of the mold and its extension which oscillates along therewith coincides with the axis of the strand path of travel at the lower terminal point of the oscillation path and forms intersection points with the upper and lower terminal or end surfaces of the oscillating hollow moldingand guide compartment, it is particularly advantageous if such intersection points are located at the end or terminal points of the oscillation path of the mold along a tangent taken with respect to the axis of the strand path of travel and the point at the lower end point at the same time constitutes the contact point of the tangent with the strand path of travel axis.

Due to this constructional embodiment, it is insured that the strand departing from the oscillating hollow moldingand guide compartment will enter the next successive strand guide arrangement which is connected with the structure with as little deviation as possible, so that there is reduced the danger of breakouts or other damage to the strand surface.

It is also possible that only one of both intersection points is located at a tangent. This can then be advantageous if by means of the relative mold movement, perpendicular to the axis of the path of travel of the strand, the outlet direction of the strand from the mold should be influenced, which under circumstances renders possible a more uniform distribution of the withdrawn thermal energy along the mold walls.

Further advantages can be realized in that the guide links or levers which constitute the connection elements between the hinges or pivot points at the mold and the frame, extend parallel. Such embodiment facilitates alignment of the lever and therefore the oscillatory movement in a most simple manner, so that there can be realized a saving in time.

If these guide levers are designed so as to have dissimilar lengths, then there are realized further advantages, in that the curvature of the path of movement of both hinge or pivot points at the mold can be selected in accordance with the requirements of the desired mold movement.

Constructional difficulties can require that a connection element of the parallelogram-like hinge or linkage mechanism be formed by a guide track instead of a guide lever. This solution renders possible a combination of a short guide lever with a guide track or path without possessing the mentioned drawbacks of guide tracks, for instance impermissible wear during operation.

Advantageously, the deviations of the paths of movement of the hinges or pivot points at the mold from the strand axis to both sides of such strand axis are uniformly divided. Consequently, the relative error, that is to say, the deviation from the desired axis of the path of travel of the strand, can be reduced by one-half.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a partial sectional view through the uppermost portion of a continuous casting installation or plant having a curved axis of the strand path of travel, and also depicting the mold, the oscillation mechanism and the uppermost guide region for the strand;

FIG. 2 schematically illustrates the course of movement for the point of intersection of the moldingand guide hollow cavity axis with the lower end surface of such oscillating moldingand guide hollow cavity; and

FIG. 3 illustrates a modified form of guide mechanism with a lever replaced by a guide track.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Considering now the drawings, it is to be understood that, as a matter of convenience in illustration, there has only been depicted therein enough of the structure of a continuous casting plant to enable one skilled in the art to readily understand the underlying concepts of this development. Turning attention therefore more particularly to FIG. 1, there will be recognized a continuous casting mold arrangement which comprises the open-end continuous casting mold l and in certain cases also an extension 1 thereof. This mold l encloses a hollow mold cavity or compartment 3 which at its end region also can constitute a hollow guide cavity or compartment. Means defining a first guide zone 2 is connected with the mold 3, this guide zone-defining means 2 enclosing a hollow guide compartment 4 and following which there is arranged a strand guide arrangement or mechanism, the uppermost segment of which has been conveniently designated by reference character 22. The mold l, the means defining the first guide zone 2 and the strand guide mechanism 22 are components of a curved strand path of travel with associated strand path of travel axis 15. Two guide levers or

links

8 and 9 are coupled for instance with the mold l and its extension 1 via the hinges or

pivot points

11 and 12. Of course, if the mold l is of the type not having a mold extension, these two levers can be directly coupled with the mold itself. These guide levers 8 and 9 are also mounted at the bearing or support locations 10. These bearing locations 10 are secured to a stationary frame 7, and wherein at such stationary frame 7 there is also arranged in known manner an oscillating drive as well as transmission devices which, however, for the purpose of preserving clarity in illustration have not been particularly shown, especially since such constitute standard structure in this particular art. It is of course possible where necessary to duplicate the arrangement of such links or levers at the opposite side of the mold, so that the latter is straddled by two pairs of such levers.

Now if the mold l and the components connected therewith, such as the means forming the first guide zone 2, are to be moved during the casting operation in an oscillatory or reciprocatory manner, then the levers or

links

8 and 9 coupled with the mold 1 at the hinge or

pivot points

11 and 12 oscillate about the bearing or support locations 10. Both of the bearing locations 10, the

levers

8 and 9, and both of the

hinge points

11 and 12 as well as the continuous casting mold arrangement thereby form a four-element hinge or linkage mechanism. The ends of the

levers

8 and 9 which are connected with the mold arrangement at the

points

11 and 12 move along circular paths of travel 17 and I8 and specifically having the

radii

34 and 35. The circular paths of

travel

17 and 18 are curved opposite to the axis of the path of travel of the strand. Normally, and as indicated above, the levers or

links

8 and 9 are arranged in pairs in order to be able to also laterally guide the mold I; it is however also possible to employ only one

respective lever

8 and 9 and to support the mold l by means of gliding surfaces or rollers against deviations perpendicular to the

levers

8 and 9.

Since the uppermost segment 22 of the strand guide arrangement and therefore the entire strand guide arrangement is not oscillated, rather is fixedly connected with the frame 7 of the installation, it is important that the mold 1 and the means defining the first guide zone 2 which forms the oscillating region, do not exceed a certain permissible deviation from the strand path of travel axis 15. This deviation amounts up to about 0.2 mm., wherein the maximum deviation is dependent upon the metallurgical quality of the cast steel. The deviation must be least at the lowermost point of the oscillatory movement, since at that location the distance between an imaginary end surface 26 of the oscillating region and the next fixed guide portion of the strand 3 guide segment 22 is also least. Now if the mold 1 is oscillated, then the lower end surface of the oscillating region coincides with the end surface of the hollow mold cavity 3. If, however, the guide element 2 arranged following the mold 1 is likewise oscillated, then, the oscillatory region first terminates at a surface of the hollow guide compartment 4 and which is disposed perpendicular to the strand path of travel axis 15, and which surface directly merges at the lowermost oscillating guide means 5.

FIG. 2 illustrates the schematic motion conditions of a reference point 28 at the lower and upper terminal points of the oscillatory path of travel. The reference point 28 is formed by the point of intersection of the hollow moldingand guide cavity axis 16 with the lower end surface 26 of the oscillatory hollow guide compartment 4. A second reference point is formed by the axis 16 together with the upper end surface 25 of the hollow mold compartment or cavity 3, namely the point of intersection 27 depicted in FIG. 1. At the lower end point of the oscillatory path of travel the axis 16 coincides with the strand path of travel axis 15 and the point of intersection 28 with the contact point 31 of a tangent 32 taken with respect to the strand path of travel axis 15. At the upper end point, the point 28 likewise is located at the tangent 32. The end surface 26 has shifted by an amount corresponding to the oscillation stroke into the position depicted by reference character 26. If the points 28 and 28' are located at tha tangent 32, then there is realized a particularly uniform transition of the oscillating components with respect to the stationary strand guide. The displacement of the point 28 into the position 28 occurs along the periphery of a circular are 18 having the radius 35, wherein the are 18 is curved opposite to the arc of the strand path of travel axis 15 having the radius 33. It is particularly advantageous if the radii 35 and 33 and the associated centers are chosen such that the point 28 is deflected uniformly to both sides of the strand path of travel axis 15, so that the

deviations

38 or 39 from the strand path of travel axis 15 are reduced by one-half. With the conventional oscillatory devices, the entire deviation or deflection is located at the same side of the strand path of travel axis 15.

Independent of the curvature of the strand path of travel axis 15 and the arrangement of the hinge or pivot points 11 and 12 at the mold 1 and where applicable at its extension 1, it can be advantageous if the

levers

8 and 9 are not of the same length, since consequently the movement of the

points

11 and 12 connected with the ends of the

levers

8 and 9 can be better accomodated to the strand path of travel 15.

The alignment of the

levers

8 and 9 can be simplified in that such are arranged so as to extend in parallelism.

If the upper point of intersection 27 depicted in FIG. 1 is not located at a tangent with respect to the strand path of travel axis 15, then, as a result the vertical oscillatory movement of the mold 1 can have superimposed thereon horizontal movements which render possible an accommodation of the mold movement to the requirements of the strand which is formed in the hollow mold cavity or compartment 3.

It is also possible to only associate the point 27 of the movement end points along a tangent with respect to the strand path of travel axis 15 and the point 28 of the movement end points do not lie upon or along a tangent 32.

A further solution has been depicted in FIG. 3 wherein the lever 8, which provides the connection element between the hinge or pivot point 11 at the mold 1 and the frame 10, is replaced by a guide track or path 41. This guide track 41 can be formed by a sliding track or a roller track, the axis 44 of which, however, is likewise curved opposite to the strand path of travel axis 15. The sliding block 42 which is connected with the mold l is guided with the aid of the guides 43 along the axis 44, which guides 43 are connected with the stationary frame 7. This axis 44 corresponds to the path of movement of the lever 8 which has been indicated by reference character 17 in FIG. 1.

It is also possible to retain the lever 8 and instead to replace the lever 9 by a guide track.

The invention is not limited to the exemplary illustrated embodiments of the equipment, rather by carrying out changes with respect to the individual components is it possible to devise still further embodiments of the invention without departing from the spirit and scope thereof. Also in the case of installations with linear hollow mold cavities of the mold and subsequently arranged curved strand path of travel axis, the proposed solution can be readily employed.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,

What is claimed is:

1. An apparatus for guiding an oscillatory continuous casting mold arrangement of a continuous casting installation having a curved axis of the path of travel of the cast strand, said guiding apparatus comprising a hinge mechanism composed of at least four elements, one of said elements being formed by said mold arrangement and having a respective hinge at given locations of said mold arrangement, another of said elements serving as a frame and being formed by a part of the structure of the continuous. casting installation, each of said hinges having a pivot point located at the mold arrangement, the movement paths of said pivot points being curved in a direction which is opposite to the curved axis of the path of travel of the strand,

2. The apparatus as defined in claim 1, wherein the hinges at given locations of said mold arrangement are located at respective end regions thereof.

3. The apparatus as defined in claim 2, wherein the mold arrangement comprises a continuous casting mold open at opposite ends thereof.

4. The apparatus as defined in claim 1, wherein the mold arrangement comprises a continuous casting mold and an extension thereof, one of said hinges being located at the continuous casting mold and other of said hinges at the extension thereof.

5. The apparatus as defined in claim 4, wherein said mold and its extension which oscillates with said mold possess a hollow moldingand guiding compartment possessing an axis, said axis being identical with the axis of the strand path of travel at the lower terminal point of the oscillatory path of movement and forming intersection points with the respective upper and lower end surfaces of the oscillating moldingand guiding compartment, said intersection points at the terminal points of the oscillatory path of travel of the mold arrangement each being located along a respective tangent taken with respect to the axis of the path of travel of the strand, and wherein the intersection point at the lower end point of the oscillatory path of travel simultaneously constitutes the point of contact of the tangent with the axis of the path of travel of the strand.

6. The apparatus as defined in claim 5, wherein only the movement end points of one of both intersection points is located upon the tangent.

7. The apparatus as defined in claim 1, said hinge mechanism further including hinges provided for said frame and two guide levers providing connection element means between the hinges of the mold arrangement and the hinges of the frame, both of said guide levers extending in substantial parallelism with respect to one another.

8. The apparatus as defined in claim 1, said hinge mechanism further including hinges of the frame and two guide levers providing connection element means between the hinges at the mold arrangement and the hinges at the frame, said guide levers possessing differ ent levers with respect to one another.

9. The apparatus as defined in claim 1, said hinge mechanism further including a first and second connection element provided between said mold arrangement and the frame, one said connection element being formed by a guide lever and the other connection element being formed by a guide track.

10. The apparatus as defined in claim 1, wherein said guide apparatus serves to uniformly distribute the deviations of the paths of movement of the hinges at the mold arrangement from the axis of the path of travel of the strand to both sides of the strand path of travel axis.

11. The apparatus as defined in claim 1, wherein the curved axis of the path of travel of the cast strand has a radius of curvature and the movement paths of said pivot point have radii of curvature, the radii of curvature of said movement paths of said pivot points being located at a side opposite to the location of the radius of curvature of the curved axis of the path of travel of the cast strand.

12. The apparatus as defined in claim 11, wherein the cast strand has an inner curved surface and an outer curved surface, the curved axis of the path of travel of the cast strand having its radius of curvature located at the side of the inner curved surface of the cast strand, and said radii of curvature of the pivot points being located at the side of the outer curved surface of the cast strand.

13. An apparatus for guiding an oscillatory continuous casting mold arrangement of a continuous casting installation having a curved axis of the path of travel of the cast strand, said guiding apparatus comprising a hinge mechanism composed of a plurality of elements, one of said elements being formed by said mold arrangement, said mold arrangement being provided with hinge means at said mold arrangement, another of said elements serving as a frame constituting a part of the structure of the continuous casting installation, said hinge means of said mold arrangement having a pivot point located at the mold arrangement, said pivot point moving through a path of travel possessing a curvature which is opposite to the curvature of the curved axis of the path of travel of the strand.

Claims

1. An apparatus for guiding an oscillatory continuous casting mold arrangement of a continuous casting installation having a curved axis of the path of travel of the cast strand, said guiding apparatus comprising a hinge mechanism composed of at least four elements, one of said elements being formed by said mold arrangement and having a respective hinge at given locations of said mold arrangement, another of said elements serving as a frame and being formed by a part of the structure of the continuous casting installation, each of said hinges having a pivot point located at the mold arrangement, the movement paths of said pivot points being curved in a direction which is opposite to the curved axis of the path of travel of the strand.

5. The apparatus as defined in claim 4, wherein said mold and its extension which oscillates with said mold possess a hollow molding- and guiding compartment possessing an axis, said axis being identical with the axis of the strand path of travel at the lower terminal point of the oscillatory path of movement and forming intersection points with the respective upper and lower end surfaces of the oscillating molding- and guiding compartment, said intersection points at the terminal points of the oscillatory path of travel of the mold arrangement each being located along a respective tangent taken with respect to the axis of the path of travel of the strand, and wherein the intersection point at the lower end point of the oscillatory path of travel simultaneously constitutes the point of contact of the tangent with the axis of the path of travel of the strand.

8. The apparatus as defined in claim 1, said hinge mechanism further including hinges of the frame and two guide levers providing connection element means between the hinges at the mold arrangement and the hinges at the frame, said guide levers possessing different levers with respect to one another.