US3496990A

US3496990A - Apparatus for continuous casting of metal

Info

Publication number: US3496990A
Application number: US683677A
Authority: US
Inventors: Walter Meier; Armin Thalmann
Original assignee: Concast AG
Current assignee: SMS Concast AG
Priority date: 1964-08-04
Filing date: 1967-11-16
Publication date: 1970-02-24
Anticipated expiration: 1987-02-24
Also published as: FR1443678A; CH414957A; GB1112832A; US3370642A

Description

Feb. 24, 1970. w. MEIER ET 3,496,990

APPARATUS FOR CONTINUOUS CASTING 0F METAL 2 Sheets-Sheet 1 Original Filed Aug. 5, 1965 INVENTORS ATTORNEYS Feb. 24, 1970 w. MEIER ET l- 3,496,990

APPARATUS FOR CONTINUOUS CASTING 0F METAL Original Filed Aug. 5, 1965 2 Sheets-Sheet 2 1? 2 L "it 9 R LL r mvgmons ATTORNEYS v United States Patent 3,496,990 APPARATUS FOR CONTINUOUS CASTING OF METAL Walter Meier, Winterthur, and Armin Thalmann, Uster,

Switzerland, assignols to Concast AG, Zurich, Switzerland Original application Aug. 3, 1965, Ser. No. 476,865, now Patent No. 3,370,642, dated Feb. 27, 1968. Divided and this application Nov. 16, 1967, Ser. No. 683,677 Claims priority, application Switzerland, Aug. 4, 1964, 10,173/ 64 Int. Cl. B22d 11/12 US. Cl. 164-232 1 Claim ABSTRACT OF THE DISCLOSURE The strand guide system comprises a roller guide positioned below a continuous casting mold. The roller guide consists of a roller guide mounting means positioned adjacent the desired course of the strand and includes a plurality of guide roll pairs. Each of the roll pairs consists of a first and second roller spaced apart by a predetermined fixed distance and so mounted as to permit a limited deflection of each of the roller pairs in a direction transverse to the longitudinal axis of the strand. By this means, proper guidance is achieved in a guide arrangement requiring less set-up time.

The present invention relates to an apparatus for continuous casting of metal and particularly refers to an apparatus for guiding the' cast strand immediately below the mold. 1

This application is a division of our copending application Ser. No. 476,865, filed Aug. 3, 1965, now Patent No. 3,370,642.

In most cases a strand guide system of this kind comprises guiding elements in the form of rollers. These strand guide systems are known as rollers guide systems and consist of a number of successive pairs of rollers, the rollers of each individual pair being disposed one opposite the other with fixed spacing between them. The sum of the distances between the individual pairs of rollers gives the guide path for the strand withdrawn from the mold, such strand being preceded by a dummy bar.

Of course, this dummy bar and the following cast strand can be satisfactorily introduced, guided and delivered only if casting is preceded by accurate setting up of the various pairs of rolls in relation to one another allowed by setting up of the entire roller guide system with respect to the mold aperture and the rolls situated downstream thereof (for example the withdrawing rolls, bending or straightening rolls).

This setting up operation is very time-consuming, particularly when curved strands are being cast from a curved mold. Any mistakes made during setting up and have a disastrous effect on casting, since rollers which have not been set up accurately may cause the strand to break because of their forces exerted on the strand or may at least result in nonuniform strand quality.

The strand guide system according to the invention obviates these disadvantages, to which end it comprises curved strand guiding means consisting of pairs of rollers where each pair is movable to a limited degree perpendicular to the surface of the strand S and centers of rollers are firmly interconnected by maintaining a fixed distance between each other.

In this way, for example, on introduction of the dummy bar self-alignment of the movable roller pairs is obtained so that exact setting up of the roller guide system is dispensed with. During casting, the strand and the guide system adjust to one another flexibly so that any extreme 3,496,990 Patented Feb. 24, 1971) or abrupt stresses on eitheri.e. either the strand surface or the rollersis obviated and the strand is guided gently but firmly along and to the end of the guide system.

Further characteristics of the invention can be seen belOW.

Two exemplified embodiments of strand guide systems according to the invention are illustrated in the accompanying drawings, wherein:

FIG. 1 is an elevation view of a continuous casting plant using the strand guide in accordance with the present invention.

FIG. 2 is an elevation view of a portion of the strand guide of FIG. 1 to enlarged scale.

FIG. 3 is a section on the line III-III in FIG. 1.

FIG. 4 is a section on the line IV-IV in FIG. 1.

FIG. 5 is a section of the movable pair of rollers on the line VV in FIG. 6, as a detail of a roller guide according to a second embodiment, and

FIG. 6 is an axial section on the line VI-VI through the movable pair of rollers of the second embodiment shown in FIG. 5.

As shown in FIG. 1, liquid metal is poured from a container not shown in accompanying drawings, into a cooled mold K. This mold K is closed by a dummy bar at its withdrawal end, reaching down to a withdrawing and straightening aggregate A. The resulting strand S is drawn from the mold K, when the solidified skin is of sufiicient strength, guided by curved strand guiding means positioned between mold K and aggregate A and cooled further as already known.

The roller guide system illustrated consists of three parts 2, 3, 4 (alternatively they could be just two or more than three), each consisting of interconnected top and bottom angle-section pairs 5 and 6 respectively. The detachable connection between the adjacent roller guide system elements is by Way of stays '7 and 8 which are affixed to the top and to the bottom angle sections 5 and 6 of two adjacent parts. Another two such stays Q and 10 are also provided at the free ends of the roller guide system parts 2 and 4. The same arrangement is provided on the other side of the rollers (see FIG. 4) at a distance corresponding to the width of the roller guide system.

Bearings to receive the journals of rotatably mounted rollers 11, 12 are provided in the stay 9; for rollers 13, 14 in stay 8; for rollers 15, 16 in stay 7; and for rollers 17, 18 in stay 11]. Thus, the stay mounted rollers are fixedly positioned in a predetermined distance apart.

Other pairs of rollers, for example the rollers 19 and 21), are provided between these fixed pairs of rollers, but are movable to a limited extent in a direction at rightangles to the strand axis while firm interconnection is maintained between them. In the exemplified embodiment shown in FIGS. 1 to 3 this is achieved by the fact that the journals of the rollers 19 on the surface forming the inner radius of the strand, and of the rollers 20 on the surface forming the outer radius of the strand are the pivot axes of

link chains

21 and 22, the rollers 11, 13, 15, 17, 19 of the pairs all being situated between the inner two chains 21 and the

rollers

12, 14, 16, 18, 20 all being situated between the two outer chains 22. The

chains

21, 22 respectively hang freely between the

fixed rollers

11, 13, 15, 17, 12, 14, 16, 18 respectively, the outer chain 22 in each case extending in parallel relationship to the inner chain 21 on the same side of the strand S. The firm distance between the two

link chains

21, 22 at each end of the rollers and hence the firm distance between the rollers 19, 21) of each movable pair is achieved by shackles 2.3 connecting the pivots of the rollers 19, 26 forming a pair. Of course, this distance is equal to the distance between the rollers of the fixed, i.e. non-slidable, pairs of rollers. While this fixed distance between the rollers 19, 20, which depends on the strand cross-section, is maintained, the pairs of rollers are movable independently to a limited extent in a direction at right-angles to the strand axis between the immovable pairs of rollers mounted on the stays 7 to 10.

The same effect is obtained with the embodiment shown in FIGS. 5 and 6 but without the use of chains. The roller guide system in this embodiment comprises rails 32 to support the consecutive pairs of rollers 30, 31, such rails being disposed on each side of the rollers and the longitudinal axis of the rails corresponding to the imaginary strand axis. As in the first exemplified embodiment, the two rollers 30, 31 of each movable pair are kept at a fixed distance according to the strand size by means of shackles 33 at the ends. Between the rollers 30, 31 each of these two-part shackles 33 extends through a boss 34 secured to the rail 32, so that they and the associated rollers 30, 31 are slidable at right-angles to the axis of the strand S at this place between a top and bottom end position. Springs 35, 36 disposed on each side of the boss 34 in the direction of displacement between the latter and a shoulder of the shackle 33 ensure that the rollers 30, 31 are always kept in a middle position between the two end positions, but being displaceable independent of neighbouring pairs of rollers vertical to the strand surface between two end positions against springs with respect to a fixed rail.

Advantageously, in the two embodiments described, the slidability of the movable pairs of rollers from the middle position in each direction is about 1" to 2".

All the fixed pairs of rollers could be driven in the manner already known, so that they could completely or partly act as withdrawing rollers.

Instead of rollers, the guide elements used may be in the form of sliding elements movable vertically in relation to the strand surface.

The continuous casting machine in FIG. 1 shows a curved mold to be used to a cast curved strand. By having a mold which is straight relative to the axis of the strand casting a straight strand, several consecutively and firmly mounted pairs of rollers 11, 12 have to be disposed to take up the forces arising from bending of the strand at the beginning of the curved strand guiding means 1.

To simplify accompanying drawings, the guiding means were confined to two faces (the upper and lower in FIG. 1) of the strand, whereas in certain cases it would be essential to have several consecutively mounted guiding rollers arranged on the other faces as well.

What is claimed is:

1. An improved strand guide for a continuous casting plant in which liquid metal is poured into a cooled mold to solidify the periphery of said metal into a skin enclosing a molten core and defining a strand which is withdrawn continuously from said mold and is further cooled after it is withdrawn from the mold, which comprises roller guide mounting means positioned below the mold to receive the strand as it is withdrawn from the mold, said roller guide mounting means comprising a pair of parallel guide rails, a plurality of pairs of rollers, each pair of which comprises a first and second roller coupled together by a shackle which spaces said rollers at a predetermined fixed distance, said shackles being resiliently mounted on said guide rails to permit deflection of said roller pairs in a direction transverse to the longitudinal axis of the strand.

References Cited UNITED STATES PATENTS 2,284,503 5/1942 Williams 164-282 2,770,021 11/1956 Harter et al 164282 X 2,895,190 7/1959 Bungeroth et a1. 16A--282 3,015,862 1/1962 Rustmeyer et al. 164-283 X 3,263,284 8/1966 Orr et al.

FOREIGN PATENTS 1,060,910 11/1953 France.

830,852 3/1960 Great Britain.

874,036 8/ 1961 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner R. SPENCER ANNEAR, Assistant Examiner US. Cl. X.R. 198167