US3452809A - Apparatus for the continuous casting of metal - Google Patents

Description

y 1, 1959 J. DUMO NT-FILLQN 3,452,809 I 'APPARATUS FOR THE CONTINUOUS CASTING 0F METAL Filed April 4, 1967 Sheet g} y 1969 J. DUMONT-FILLON 3,452,809

APPARATUS FOR THE CONTINUOUS CASTING OF METAL Filed April 4, 1967 Sheet g of 2 United States Patent O 56, Int. Cl. B22d 11/06 US. Cl. 164278 Claims ABSTRACT OF THE DISCLOSURE An apparatus for the continuous casting of metal and including an elongated fiow mold having walls formed by four endless flexible bands movably supported on a plurality of rollers, wherein the bands and the rollers supporting the same are arranged in such a manner that the four bands delineate a space in the form of a right pyramid frustum, and preferably including pressure means cooperating with the bands for pressing the same against the metal poured into the aforementioned space through the end thereof defined by the larger end face of the frustum for maintaining the bands over the whole length of the mold in contact with the metal poured thereinto during solidfication and shrinkage of the latter.

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for continuous metal casting including an elongated fiow mold into which metal is cast at one end thereof and solidifies therein so that solidified metal may be withdrawn continuously from the other end of the mold. More specifically, the present invention relates to an apparatus including an elongated flow mold the walls of which are movable.

Elongated flow molds are known in the art in which the walls thereof are formed from movable bands or chains; however, in the flow molds known in the art the spacing between each two opposite Walls of the mold is fixed so that during progressive solidification and shrinkage of the liquid metal poured into the mold air spaces are formed between the mold walls and the surfaces of the solidified metal, which air spaces have a relatively small heat conductivity and retard thereby considerably the cooling of the metal. Sometimes even a reheating of the solidified and rather thin metal crust will occur in whic case a piercing of this crust is unavoidable.

It is an object of the present invention'to overcome this disadvantage of flow molds known in the art.

It is a further object of the present invention to provide a flow mold the walls of which are formed by movable bands arranged and constructed in such a manner to maintain over the whole length of the mold contact with the metal solidifying therein despite the shrinkage thereof.

SUMMARY OF THE INVENTION With these objects in view, the apparatus for the continuous casting of metal according to the present invention mainly comprises an elongated flow mold having a longitudinal axis and opposite open ends and a cross section in the form of a right quadrangle and having walls formed by four endless flexible bands with a plurality of rollers supporting the bands movable in longitudinal direction, the bands and the rollers supporting the same are arranged so that the longitudinal axis of each band and the axis of the mold are inclined with respect to each other and located in different planes, each band axis being inclined in the same sense and through the same angle ice with respect to the axis of the mold, and so that each band engages with one side edge thereof the band adjacent thereto and so that a plane passing through the axis of one band and the one side edge thereof intersects the band adjacent thereto at right angles such that the four bands delineate a space in the form of a right pyramid frustum having quadrangular end faces, the larger of which being located at one end of the mold into which metal is poured, means arranged in the region of the one end of the mold for pouring liquid metal thereinto, and Withdrawal means arranged in the region of the other end of the mold for continuously withdrawing cast metal therefrom.

In a preferred form according to the present invention, the rollers which support each band are articulately mounted movable in two directions transverse to each other relative to a fixed support in such a manner that the bands may define a space in the form of a right pyramid frustum the apex angle of which may be changed corresponding to the form which the solidifying metal will take during its shrinkage.

The apparatus according to the present invention may also have the following characteristics combined with the characteristics mentioned above:

(a) The apex angle of the pyramid frustum defined by the bands is equal to the apex angle formed by the four faces of the solidified product obtained during shrinkage of the metal;

(b) The apparatus may include pressure means cooperating with the bands for maintaining the latter over the whole length of the mold in contact with the solidifying metal.

It is to be understood that the endless band is a metal band the extremities thereof are fixed by welding or otherwise to each other, for instance in a similar manner as the ends of a transmission belt are fixed to each other.

One of the aims and advantages of the apparatus according to the present invention is that constant contact between the metal and thefour faces of the flow mold during passage of the metal through the latter and solidification thereof is maintained despite the shrinkage of the metal caused during its solidification and cooling. In fact, the bands are arranged in such a manner that the space defined by the same forms a right pyramid frustum which is generally of the form that the metal takes in the flow mold due to its shrinkage.

In addition, when the flow mold is formed by bands which are articulately mounted with freedom of movement in two directions, the bands may define a right pyramid frustum with a variable apex angle which in each case has the form the metal will take during its solidification and shrinkage. This constitutes another advantage of the present invention because it is in this way possible to use the same flow mold for the casting of different metals which have expansion coefficients differing considerably from each other and which therefore will shrink during their solidification in a different manner, and nevertheless assure during casting of each of the metals a perfect contact of the four faces of the flow molds with the metal poured therein and shrinking during its solidification.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic partly sectioned side view of an apparatus according to the present invention;

FIG. 2 is a top view of the apparatus shown in FIG. 1, with the means for pouring liquid metal into the mold omitted;

FIG. 3 is a sectional view taken along the line a-b of FIG. 4 and illustrating a detail of the apparatus; and

FIG. 4 is a side view of the detail shown in FIG. 3, partly sectioned, the section being taken along the line c-d of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, it will be seen that the apparatus of the present invention mainly comprises an elongated flow mold 1 having opposite open ends and means for feeding molten metal 2 into the upper open end of the mold, which may comprise a receptacle 3 arranged above the mold and having a discharge passage arranged substantially along the mold axis. The speed at which the molten metal is fed into the mold is regulated in a known manner by the operator, for example, by main taining a constant level 4 of molten metal in the receptacle 3, and the molten metal is fed into the receptacle 3 in a. manner known per se, not forming part of the present invention.

The elongated flow mold 1 is formed by four flexible sheet metal bands of equal length 5, 5a, 5b, and 50, each movably arranged in an endless loop about three guide rollers that is the guide rollers 6, 7, and 8 or 6a, 7a, and 8a or 6b, 7b, and 8b or 60, 7c, and 80, respectively, and the axes of these rollers are respectively designated 9, 10, 11 or 9a, 10a, 11a or 9b, 10b, 11b or Be, 10c, 11c (certain of these rollers or axes are not visible in the drawings, which however will not prevent proper understanding of the figure). The axes of the rollers which guide the respective bands, for instance the axes 9, 9a, 9b and 9c of the rollers 6, 6a, 6b and 6c are not located in a horizontal plane, but are inclined with respect to each other. This arrangement has two consequences:

*(1) The longitudinal axis of each band is inclined with respect to the longitudinal axis 13 of the elongated flow mold, as for instance clearly shown in FIG. 1 for the axis 12 of the band 5;

(2) Each band abuts with one of the longitudinal edges thereof obliquely inclined onto the band adjacent thereto and this holds true going in one direction about the mold for all four bands, The angle included between the longitudinal axis of each band and the longitudinal axis of the mold is for reason of clarity exaggeratedly shown in the drawing and in the actual construction these angles are in order of a few degrees.

From FIG. 1, it can be clearly seen that the band 5 abuts with its left longitudinal edge, as viewed in FIG. 1, obliquely inclined onto the band 5b and the band 5b abuts with one longitudinal edge obliquely inclined onto the band 50, whereas the band 56 abuts with one longitudinal edge against the band 5a and the latter abuts with one longitudinal edge obliquely inclined onto the band 5. The inner space thus defined by the four abutting bands is a pyramid frustum, that is a space corresponding exactly to the shape the metal will assume as it passes through the flow mold due to its solidification and corresponding shrink-age. The metal after solidifying leaves the fiow mold 1 in form of an endless ingot 14 and the apparatus includes further means for continuously withdrawing the ingot 14 from the flow mold, which means are shown in FIG. 1 as a pair of withdrawal rolls 15 and 15a driven in opposite direction by motors not shown in the drawing.

Each roller of a set of rollers which respectively support the above-mentioned four bands is supported at the opposite ends of its axis in a common movable frame. Thus, the rollers 6b, 7b and 8b are supported at opposite ends of their axes 9b, 10b and 11b in the movable frame 16b, and the movable frames 16, 16a and 160 support respectively the axes of the rollers 6, 7, 8; 6a, 7a,

8a; and 6c, 70, 8c. Each of the frames 16, 16a, 16b, and 16c carries fixedly connected thereto a plurality of arms laterally projecting therefrom which turnably sup port small pressure rollers serving to maintain the respective bands in close contact with the metal during its solidification. Thus, as clearly shown in FIG. 1, the frame 16b carries the arms 17b, 18b, 19b and 20b fixedly connected thereto which respectively tum-ably support the axes of the small pressure rollers 21b, 22b, 23b and 24b. Likewise, the frame 16, best shown in FIG. 4, carries the arms 17, 18, 19, and 20 which respectively turn-ably support the small pressure rollers 21, 22, 23, and 24, and it is understood that the other two frames 16a and 16c likewise carry a plurality of arms supporting small pressure rollers in the same manner as the frames 16b and 16 while only the arms 17a on the frame 161: and the pressure roller 21:: mounted thereon is shown in FIG. 1.

Each of the small pressure rollers is pressed against the respective band by springs, and the springs 25, 26, 27 and 28 respectively cooperating with the pressure rollers 21-24 are clearly shown in FIG. 4, whereas the springs 25b, 26b, 27b and 28b cooperating with the pressure rollers carried by the arms on the frame 16b are shown in FIG. 1 and it is to be understood that the pressure rollers carried by the frames 16a are likewise pressed by springs against the corresponding bands, of which springs only the springs 25a and 26a are likewise shown in FIG. 1.

A plurality of nozzles 29 mounted on the respective frames between the rollers serve to spray jets of atomized water 30 against the surf-aces of the respective bands which are opposite the surfaces thereof which contact the metal, to accelerate cooling of the latter.

In order not to overload the drawing with too many details, the rollers have been shown in a simplified manner in the drawing. Actually all rollers which support band portions in contact with the metal are provided on the peripheral surface thereof with small projections on the extremities of which the bands are supported. This arrange ment permits the cooling water to cool the bands also in the region of the rollers. Likewise, for reason of clarity, the means for pivotally supporting the movable frames 16, 16a, 16b and 160 are omitted from FIG. 1, and the support arrangement is shown in further detail for the frame 16 in FIGS. 3 and 4.

In the top view of FIG. 2 the receptacle 3 is omitted and FIG. 2 more clearly shows the bands 50 movable on the rollers 6c, 70, as well as the frame 160.

FIGS. 3 and 4 more clearly illustrate the pivotal mounting of the frame 16 which carries the rollers 6, 7, 8 supporting the band 5. It is to be understood that the three other frames 16a, 16b, and 160 are supported in the same manner as shown for a frame 16 in FIGS. 3 and 4. FIG. 3 also illustrates that the roller 23 is provided at the peripheral surface thereof with small projections 31 in staggered arrangement, and it is also to be understood that the other rollers which support band portions in contact with the metal are likewise provided with such projections.

The frame 16 which supports the axes of the rollers 6, 7, 8 on which the band 5 is movably mounted comprises two side plates 32 and 33 connected to each other by cross plates 34 and 35. The cross plate 34 carries a swivel joint 36 which is connected to a stationary support 37 by means of a fixed arm 38. An hydraulic jack 39 pivotally connected at one end at 40 onto a column fixed to the stationary support 37 is pivotally connected at the other end thereof at 41 to the side plate 33 of the frame 16. Due to the pivot joint 36 a primary pivotal movement of the frame 16 is obtained about an axis passing through the center of the pivot joint 36 and being parallel to the portion of band 5 in contact with the metal, this axis is perpendicular to a plane defined by the axis of the hand 5 and the center of the pivot joint 36. A concomitant pivotal movement of the other frames 16a, 16b and 160 is obtained in the same manner by similar mechanical arrangements (jack and pivot joint), which produces, due to the pivot joint 36, a second pivotal movement of the frame 16 about an axis passing through the center of the pivot joint and perpendicular to the face of the band 5 which is in contact with the metal. This second pivotal movement will also be produced in the same manner of the frames 16a, 16b and 160. It is recalled that the faces of the bands which are in contact with the metal are plane faces.

The synchronism of this double pivoting of the frames 16, 16a, 16b, and 160 is obtained by known means, for example by automatic control of the hydraulic jacks, and the double pivotal movement of the four frames will result in a modification of the volume of the flow mold 1, and especially a variation of the apex angle of the pyramid frustum defined by the bands. According to the invention, it is therefore possible to adapt the shape of the flow mold and to vary the same as a function of the coefiicient of shrinkage of the metal to be cast and solidified.

The arrangement according to the present invention can be used advantageously for the continuous casting of metals such as lead, copper, aluminum, antimony, different alloys, etc., and especially for the continuous casting of steel.

The apparatus above-described may be operated during continuous casting of steel in the following manner:

After blocking the various pressure springs 25, 26, 27, 28, etc. which press the small pressure rollers against the respective band, a steel block of a cross section slightly smaller than the lower outlet end of the mold is introduced into the flow mold with the lower end of the steel block extending between the withdrawal rollers and 15a. The aforementioned springs are then released so that the steel block is held between the bands and between the withdrawal rollers. The upper surface of the steel block is then covered with a layer of asbestos and granulated steel, and molten metal is then discharged from the receptacle 3 into the upper end of the flow mold 1 while water is sprayed through the nozzles 29 onto the bands so that the molten metal progressively solidifies in contact with the cooled band. Subsequently thereto, the motors which turn the withdrawal rollers 15 and 15a are started, and the metal gradually fills the flow mold as the steel block is downwardly withdrawn by means of the withdrawal rollers. At the same time, the bands 5, 5a, 5b, and 5c are dragged along by the downward movement of the steel block and subsequently thereto by the solidified metal which in turn is gripped and dragged along by the rotating withdrawal rollers 15 and 15a.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus for continuously casting metal differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for continuously casting metal and having an elongated flow mold the walls of which are formed by flexible endless bands arranged to define a pyramid frustum, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

While in the arrangement illustrated in the drawing and above-described, the flow mold has a square cross section, it is to be understood that the principles of the above-described fiow mold may also be used for a flow mold of rectangular cross section.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. An apparatus for the continuous casting of metal comprising, in combination, an elongated flow mold having a longitudinal axis and opposite open ends and a cross section in form of a right quadrangle and having walls formed by four endless flexible bands and a plurality of rollers supporting the bands movable in longitudinal direction, said bands and said plurality of roller supporting the same are arranged so that the longitudinal axis of each band and said axis of said mold are inclined with respect to each other and located in different planes, each band axis being inclined in the same sense with respect to the axis of the mold, and so that each band engages with one longitudinal edge thereof the band adjacent thereto so that a plane passing through the axis of one band and said one longitudinal edge thereof intersects the band adjacent thereto at right angles such that said four bands delineate a space in form of a right pyramid frustum having quadrangular end faces, the larger of which being located at one end of the mold; means arranged in the region of said one end of said mold for pouring liquid metal thereinto, and withdrawal means arranged in the region of the other end of the mold for continuously withdrawing cast metal therefrom.

2. An apparatus as defined in claim 1, and including mounting means, one for each band, mounting the rollers of each band turnably about their axes, stationary support means, and means articulately connecting each of the mounting means to said stationary support means movable in two directions transverse to each other relative to said stationary support means in such a manner that the apex angle of the pyramid frustum defined by said bands may be changed corresponding to the shape the metal solidifying in the mold will assume during its shrinkage.

3. An apparatus as defined in claim 1, wherein the apex angle of the pyramid frustum defined by said bands is equal to the apex angle formed by the four faces of the solidified product during shrinking of the metal.

4. An apparatus as defined in claim 1, and including 5 pressure means cooperating with said bands for pressing the same against the metal poured into said mold for maintaining the bands over the Whole length of said mold in contact with said metal during solidification and shrinkage of the latter.

5. An apparatus as defined in claim 1, and including an elongated frame for each band carrying two of said plurality of rollers at opposite ends thereof turnably about their axes, stationary support means, means articulately connecting said frame intermediate its end to said support means movable in two directions transverse to each other, and biasing means connected to said frame for biasing that one of said rollers which is closer to said other end of said mold toward the mold axis.

6. An apparatus as defined in claim 5, and including a plurality of pressure rollers mounted on said frame between said two rollers and in engagement with the face of said band facing away from said mold axis turnably about their axes and movable independent from each other toward and away from said mold axis, and a plurality of biasing means, one for each pressure roller and respectively cooperating with said pressure rollers for biasing the same toward said mold axis.

7. An apparatus as defined in claim 5, wherein said biasing means connected to said frame comprise fluid operated jack means.

8. An apparatus as defined in claim 6, wherein said biasing means cooperating with said pressure rollers comprise compression springs.

9. An apparatus as defined in claim 1, and including means for cooling said bands.

References Cited UNITED STATES PATENTS 8 FOREIGN PATENTS 66,280 3/1956 France. 108,184 8/ 1939 Australia. 491,341 8/1938 Great Britain.

5 12,352 8/1962 Japan.

I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner.

594,583 11/1097 WOOd 164 27s 2,956,320 10/1960 P11151161 164-87 10 us. 01. X.R. 3,226,782 1/1966 Schultz 164283 16487

Images