EP0468607B2 - Fluid cooled mould for continuous casting of metals - Google Patents

Abstract

The invention relates to a fluid-cooled mould for the continuous casting of metals, in particular steel, with a shaping wall consisting, in particular, of a metallic material, which is secured on a supporting plate and is provided with connections for a cooling fluid for the purpose of cooling the wall. In order to reduce the weight of the mould suspension, including the oscillation device to be moved and thereby to enable higher oscillation frequencies to be set for the minimum power requirement in the case of fluid-cooled oscillating moulds, it is proposed to secure spring elements (7) on that side of the supporting plate (2) which faces away from the wall (1). The spring elements are secured on one side in a uniformly distributed manner and have a considerably lower stiffness in the casting direction than in the two transverse directions. In addition, the invention proposes that the spring elements (7) extend in a direction transverse to the casting direction, that the opposite ends of the spring elements (7) be secured on a carrier plate (6), that the carrier plate (6) be connected to a fixed base frame (12) and that an oscillation device (16,17) engage on the supporting plate (2). <IMAGE>

Description

The invention relates to a liquid-cooled mold for the Continuous casting of metals, especially steel.

Depending on the strand format to be generated (strand dimension) usually for the production of billet, bloom and round strands Tube molds, used for the manufacture of slab plate molds.

Regardless of the strand format, the molds are in the casting direction oscillates. A sinusoidal mold movement is preferred, the speed of the downward movement of the mold being greater than that is usually constant strand withdrawal speed (negative strip).

The frequency and the stroke height of the oscillation movement is based on the Strand withdrawal speed coordinated. For example, at Slab formats with dimensions of 250 mm x 2000 mm Line withdrawal speeds of 1.3 m / min a frequency of approx. 100 Vibrations per minute at lifting heights (amplitude of a vibration) of 4 up to 15 mm common values. In terms of frequency, too higher vibration numbers have been proposed. The realization But so far failed due to the size of the mass to be moved. For the specified slab format, the mass to be moved is approx. 30 t. At Tube molds, such as those used to produce round strands or Rectangular strands in billet or bloom format (100 - 500 mm ⊘ or 100 x 100 - 400 x 400 mm) are used, the mass of the mold lower and lies between 1.3 - 2.5 t, but are also here comparable difficulties to determine when a certain amount the oscillation frequency at low lifting heights and high Strand withdrawal speeds of e.g. B. 4 m / min and below

Maintaining the "negative strip", ie leading the mold over the strand withdrawal speed during the downward stroke should.

The invention has for its object in liquid-cooled, The molds are suspended under oscillating molds Inclusion of the oscillation device in the to be moved Reduce mass in order to increase the number of vibrations with the lowest possible To be able to adjust power requirements.

The object is achieved according to the invention with a mold according to the generic term of claim 1 with the measures of the characterizing part of Claim 1 solved. Advantageous further developments of the invention are specified in the subclaims.

Using the drawings, the embodiments of the invention represent, the invention is to be explained in more detail.

Fig. 1

eine perspektivische Ansicht einer Plattenkokille für Brammen,

Fig. 2

eine perspektivische Ansicht des durch die Erfindung näher beschriebenen Bereichs der Kokille nach Fig. 1,

Fig. 3

eine Einzeldarstellung einer Stütz- und Halteplatte nach Fig. 2,

Fig. 4

eine Seitenansicht nach dem Schnitt A-A nach Fig. 1,

Fig. 5

einen Schnitt B-B nach Fig. 1,

Fig. 6

eine Draufsicht auf eine Rohrkokille,

Fig. 7

einen Schnitt C-C nach Fig. 6.

Fig. 8

eine Prinzipdarstellung der Lage der Federelemente.

Fig. 9

einen Längsschnitt durch die montierten Federelemente,

Fig. 10

eine Aufsicht auf Figur 9 sowie die

Fig. 11 a-c

Einzelheiten der Anordnung von einer, zwei bzw. drei Federn.

Show it

Fig. 1

a perspective view of a plate mold for slabs,

Fig. 2

2 shows a perspective view of the area of the mold according to FIG. 1 described in more detail by the invention,

Fig. 3

3 shows an individual representation of a support and holding plate according to FIG. 2,

Fig. 4

2 shows a side view according to section AA according to FIG. 1,

Fig. 5

2 shows a section BB according to FIG. 1,

Fig. 6

a top view of a tubular mold,

Fig. 7

6 shows a section CC according to FIG. 6.

Fig. 8

a schematic diagram of the location of the spring elements.

Fig. 9

a longitudinal section through the assembled spring elements,

Fig. 10

a supervision of Figure 9 and the

Fig. 11 ac

Details of the arrangement of one, two or three springs.

In the drawings, the same parts have the same reference numbers Mistake.

The plate mold shown in Fig. 1 consists of the shaping Wall 1 in the form of copper plates that form the mold cavity for the form generating strand. The copper plates 1 are on support plates 2 attached. The copper plates 1 are water-cooled. The coolant is via flexible lines and the connections 14 and Flow channel 15 (Fig. 2) to the support plates 2 of the broad sides or dissipated by these. The supply of the copper plates 1 of the Narrow sides 3 can be done in the same way. The narrow sides 3 are clamped between the broad side plates 1, 2 and are from Adjustment devices 5 with which the width of the slab to be produced is set, worn in turn on clamping elements 13, which the Connect support plates 2 outside the flow channels 15, attached are. On the outside, ie the sides of the Support plates 2 is a plurality of spring elements 7 - here leaf springs - fixed on one side. Of course, can also be used as spring elements Laminates are used which are made of leaf springs vulcanized intermediate layers are formed from elastomers. The Leaf springs are evenly spaced apart across the surface distributed and extend transversely to the casting direction. They point in the casting direction a much lower rigidity than in both transverse directions. With her the leaf springs are at the other ends a support plate 6 attached. The support plates 6 are in turn hydraulic, via spring-loaded uncouplable adjusting and adjusting elements 11 (see FIG. 5) on one locally, the support plates 6 and the narrow side plates 3 encompassing Base frame 12 attached. Through the adjustment and adjustment elements 10, 11 is an adjustment and alignment of the broadsides to different Slab thicknesses given corresponding narrow side plates 3. The for Oscillation necessary device 16, 17, according to FIGS. 2 and 5 in the form of a hydraulic cylinder 16 as a drive via a lever 17 attacks the or the support plates 2 at the foot of the mold.

This basic solution ensures that only the actual crystallizer, i.e. the copper plates with the associated ones Support plates including the adjustment device for the narrow sides are to be moved by the oscillation device. Compared to the conventional slab molds will reduce the number of parts to be moved Mass achieved by about 60%. On the one hand, this can result in a higher Vibration number can be achieved, on the other hand, the drive (16) Oscillation device built smaller and on the base frame (12) be attached. This is also a shortening or a Reduction in the transfer of forces from the drive to the mold otherwise necessary mechanics. This is another advantage given that the cooling water from the oscillating plates (1, 2, 3) Base frame (12) from hose connections 14 through the support plates (6) and one on the back of the support plates (2) Flow channel 15 is supplied. Through the water flow over the Broad sides, the use of several hose connections is possible, so that the water distribution and pressure adjustment largely in non-oscillating area of the mold happen and the Flow cross-section on the moving support plates can be minimized. It is also possible to use the upper and lower row of spring plates run closed and the sides by elastic elements to seal the components located within this area to the extremely aggressive environmental influences in the plant area protect.

In the tubular mold shown in FIGS. 6 and 7 there is Wall 1, which forms the mold cavity for the strand to be produced, from a copper tube of circular cross-sectional shape with curved Longitudinal axis 19. Of course, tubes with rectangular or polygonal cross-sectional shape and straight longitudinal axis 19 are used. The copper tube 1 is in a manner known per se Wasserleitmantel 20 surrounded and is provided on the pipe ends Flanges 18 and one the copper tube 1 and the water jacket 20 enclosing tubular support plate 2 held. The flanges 18 have a rectangular shape when viewed from above. At two each other opposite sides of the flanges 18 are the spring elements 7, too here designed as leaf springs, arranged transversely to the casting direction. The Spring elements 7 are on mounting strips 8 on a support plate 6, which is connected to a base frame 12, attached. The mold is by means of a hydraulic cylinder 16 which on the one hand on the Support plate 2 attacks and on the other hand on the support plate 6 supports a connecting web 21, oscillatable.

So here is the oscillation drive 16 without the intermediary of usual intermediate gear or linkage directly with the oscillating mass connected. The spring elements 7 are with their Longitudinal axis 7 'aligned so that their imaginary extensions in Center of curvature 22 of the mold, or in one through the Center of curvature 22, perpendicular to the spring element axes 7 ' running line, cut. As with a mold tube with a straight one Axis 19 the "center of curvature" is infinite, the arranged one above the other, attached to the two pipe ends Spring elements 7 in total parallel to each other.

It is part of the scope of the invention for a straight mold Axis 19, the flange 18 in plan view with polygonal or round Form peripheral limitation and the spring elements 7 in a more uniform manner Arrange the distribution in such a way that the axes 7 'of the spring elements 7 lie a radius beam that starts from the axis 19 of the mold.

The invention is of course also applicable to a tubular mold the cooling takes place through cooling channels running in the wall 1. Here, the tubular support plate 2 can rest directly on the wall 1 and the attachment of the spring elements in the same way as described for the slab mold.

As can be seen from the above explanations, the connection between fixed (support plates) and movable (support plates) mold parts via the spring elements is designed such that, in particular in the case of plate molds
a relative movement of the inner to the outer plates in the casting direction is possible around the underlying oscillation stroke,
the inner and outer plates form a unit that is rigid against bending around the vertical axis (in particular from thermal stresses),
radial forces from ferrostatic pressure and the required preload as well
Shear forces in the direction of the longer slab edge can be transferred from the inner to the outer plate,
the natural frequency of the total spring stiffness of the spring leaves in connection with the oscillating mass of the mold corresponds to the desired highest operating frequency and
From the dynamic zero position (static countersink), the highest possible accuracy of the casting radius is guaranteed in the range of the intended oscillation amplitude.

The technical design of a system according to the invention will be explained in more detail using an example. A strand of dimensions 1600 x 250 mm with a max. Strand withdrawal speed of 3 m / min can be generated on a sheet line with 10500 mm radius. The oscillating mass results from the strand format to be cast and the design of the crystallizer plates used. If these parameters change under other conditions, this fact can be taken into account by changing the spring parameters accordingly. The following values are selected with regard to the mold: oscillating mass m = 5000 kg Max. Stroke s = ± 2.2 mm Max. frequency f = 6 Hz Handlebar length l = 350 mm Handlebar width b = 70 mm Number of handlebars n = 2 x 8 x 14 = 224

Stroke and frequency result from the casting speed to be achieved, whereby according to the underlying concept, small amplitudes and high frequencies are preferred because
with increasing operating frequency, the spring stiffness required for resonance increases and thus the static sag decreases and
with a lower amplitude, the alternating bending stress of the spring leaves decreases.

Handlebar length, width and number result essentially from the available installation space and the design of the used Crystallizer plates, here are different designs possible, in which case the handlebar thicknesses must be adjusted accordingly.

Based on the above data, the following values are required: Total spring rate C = 7170 N / mm Handlebar thickness d = 3.6 mm static reduction Δy = - 6.8 mm

The required total spring rate of the system is calculated for the desired highest operating frequency C = mx (2π xf) 2 ,

With a mold designed in this way, one results Guiding accuracy (deviation of the mold edge from the large radius of <10 µm.

The guidance accuracy is therefore dependent on the dimensions and the mounting positions of the handlebars. The handlebars are arranged as follows:
Starting from an orientation in which the extension of the imaginary connecting lines from the inner and outer articulation points of all links point to the center of the casting
the hinge-side articulation points shifted upwards by the amount of the static sag. This arrangement is a prerequisite for the slight deviation of all points of contact between the strand and the shaping wall.

Under static sinking, the change in position is Spring elements due to the load with the mass to be oscillated understand. Starting from the constructive zero position is offset the point of attachment of the spring elements on the support plate around the Amount of the static sinking the dynamic zero position, i.e. the "Center of oscillation". 8 are the two shaping walls designated 1, the strand between them take up. The shaping walls are on the support plates 2 attached. The support plates 2 are over with the support plate 6 Spring elements 7 connected.

With respect to the position of the spring and the support plates 2 and support plates 6 to each other the "constructive zero position" is denoted by a. The The point of attack of the leaf springs 7 on the support plate is by the amount of static sag. The dynamic results from this Zero position b. The Dynamic zero position is at the same time the operating point around which the support plate 2 with the shaping wall 1 oscillates, the top dead center of the oscillation with c and the bottom dead center of the oscillation are designated d. For the recommends the above-described design of a mold according to the invention a hydraulic cylinder in particular as an oscillation drive. Since the oscillating plates due to the spring design in the resonance range swing, the hydraulic cylinder can be designed small, because in the Basically only the friction between the mold wall and Strand shell must be overcome. Since also the hydraulic cylinder can be operated with operating pressures below 10 bar Power source for example the cooling water system of the mold or that Machine cooling applicable. Furthermore, that with the invention is recommended feasible solution due to the design with the smallest space requirement for use in multiple continuous casting plants for billet and Bloom formats.

The following are particularly to be regarded as advantages of the invention as a whole:
minimal oscillating mass,
less oscillating components and consequently less influence of the natural frequency of components involved in the vibration on the target course of the oscillation,
high guidance accuracy, due to the design, play-free and low-wear design,
simple drives - there are e.g. B. Plunger can be used as drive elements - because the oscillation is self-sufficient for a short time due to the spring and kinetic energy stored in the system,
Reduction of the required drive power by using the resonance,
due to the high possible frequency with the smallest amplitudes, an improvement in the surface quality with simultaneously increased casting speed.

It is also possible to use non-sinusoidal path-time profiles Mold oscillation with sinusoidal force-controlled excitation realize.

In the following, the design of the spring elements based on the Figures 9-11 are explained. It is essential that the Spring elements in the production as coherent units can be produced or as spring packs, which then only must be inserted into the jaws in a simple meadow before a screw connection and thus attachment to the corresponding Consoles of the support plate or support plate are made. For the assembly there are no differences, whether it is a single spring is in the spring element or a Multiple arrangement of, for example, two or three springs. For the distance or the storage of the spring element (s) in the Clamping pieces and thus the clamping jaws ensure accordingly dimensioned intermediate layers.

In these drawings, the parts of the mold are between those the spring elements are arranged, not shown.

It follows in detail from FIG. 9, however, that at the Support plate or support plate brackets 117 are arranged. This Consoles form support surfaces for the clamping jaws 111 Clamping jaws 111 have a circular cross section Drilling on. Clamping pieces 112 are arranged in this bore, which are made from two cylinder sections. In their form are, as can be seen from Figure 9, these clamping pieces Adjusted bore in the jaws and in turn point in Cross-section seen a semicircular on the bore inner wall adjacent surface as well as a flat surface that the or Spring element (s) facing (are). When running like them 9, there are two spring elements 116 intended. Is located between these two spring elements 116 at the respective ends, i.e. in the area of the jaws or Clamping pieces, an intermediate layer 114 keeping this at a distance. This plane-parallel intermediate layer is used in the manufacture Adjusted nominal size of the spring package provided.

If the spring elements always have the same dimensions, can also the intermediate layers made of consistently thick Flat material can be produced. 11a is different only one spring element is provided from the illustration in FIG. 9, corresponding intermediate layers above and below are shown. For comparison, FIG. 11b corresponds to FIG Representation in Figure 9 and finally in Figure 11c is a Arrangement with three spring elements can be seen in the corresponding thinner intermediate layers are used. When manufacturing the Spring elements are through the sprags and that or Spring elements drilled through holes, and then one Dowel sleeve 113 hammered in, which then at both ends Spring element or the spring elements with the clamping pieces holds together. This unit can then laterally in the Holes are inserted into the jaws, and then the screws indicated with 115 are replaced by a corresponding one Bore in the jaws or through the adapter sleeve and the bracket 117 passed through and when screwing is not only done an adjustment, but also a firm connection between the spring elements and the console via the clamping pieces or clamping jaws. It is essential that - and this follows from FIG. 9 - the Screws 115 have a smaller diameter than that Inner dimension of the adapter sleeve. Due to the shape of the surfaces the Clamping pieces or jaws and the dimensioning of the clamping screws is achieved that both in the operation of the mold axial forces as well as bending moments from the spring elements frictionally transferred to the consoles. It works Articulation described in operation as a rigid connection. The Effect as a rotating or rotating push-joint is on the Adjustment process limited.

Claims (14)

1. A fluid-cooled, oscillatably mounted mould for the continuous casting of metals, especially steel, comprising shaping walls (1) particularly of a metal material which are attached to support plates (2) and comprising connections (14) for a coolant for cooling the walls, wherein spring members (7) are attached at one end evenly distributedly on mutually opposing support plates (2) directly on the side of the broad sides remote from the walls (1) or via flanges connected with the support plates, said spring members (7) being substantially less rigid in the same direction as the casting direction than in the two transverse directions and extending in a direction perpendicular to the casting direction, the opposing ends of the spring members (7) are attached to supporting plates (6), the supporting plates (6) are connected with a stationary base frame (12), an oscillation device (16, 17) acts on the support plates (2) and the position of the spring members (7) is aligned with the centre of curvature of the mould in such a way and the coupling point of the spring members (7) to the support plate (2) is displaced by the amount of the static deflection in such a way that they assume such a position in the loaded state as they would assume in the unloaded state in the case of alignment with the centre of curvature or an axis (22) positioned through the centre of curvature.
2. A fluid-cooled, oscillatably mounted mould for the continuous casting of metals, especially steel, comprising shaping walls (1) particularly of a metal material which are attached to a support plate (2) and comprising connections (14) for a coolant for cooling the walls, wherein spring members (7) are attached at one end evenly distributedly on the support plate (2) directly on the side remote from the walls (1) or via flanges connected with the support plate, said spring members (7) being substantially less rigid in the same direction as the casting direction than in the two transverse directions and extending in a direction perpendicular to the casting direction, the opposing ends of the spring members (7) are attached to a supporting plate (6), the supporting plate (6) is connected with a stationary base frame (12) and an oscillation device (16, 17) acts on the support plate (2) and wherein the walls (1) are of tubular construction and are connected with the support plate (2) at both ends with flanges (18) lying perpendicular to the tube axis, the flanges (18) of the support plate (2) being rectangular in plan view and the spring members (7) being attached to two opposing sides of the support plate (2) or the flanges (18), and the position of the spring members (7) is aligned with the centre of curvature of the mould in such a way and the coupling point of the spring members (7) to the support plate (2) is displaced by the amount of the static deflection in such a way that they assume such a position in the loaded state as they would assume in the unloaded state in the case of alignment with the centre of curvature or an axis (22) positioned through the centre of curvature.
3. A fluid-cooled mould according to claim 1 or claim 2, characterised in that the overall spring rigidity of the spring members (7) in the casting direction is precisely such that the oscillating system of spring members (7) and oscillating mass has a natural frequency of the magnitude of the required highest operating frequency.
4. A mould according to claim 1, characterised in that the walls (1) are formed of plates with mutually opposing, displaceably arranged narrow side plates (3) held between two broad side plates (1, 2), the support plates (2) for the walls (1) of the broad sides lying parallel to the plate plane of the walls (1), in that the spring members (7) connecting the support plates (2) with the supporting plates (6) extend in rows over the height and breadth of the plates (2, 6), in that the supporting plates (6) are adjustable with respect to each other by means of spring-loaded, hydraulically uncouplable setting (10) and adjusting (11) members, which are arranged on the stationary base frame (12), and in that the base frame (12) spans the mould.
5. A mould according to claim 4, characterised in that the narrow side plates (3) are provided with forming elements on their outer faces in contact with the broad side plates (1, 2), which forming elements engage form-fittingly in guides (4) in the walls (1), which guides (4) extend at the top edge of the broad sides perpendicularly to the casting direction.
6. A mould according to claims 1 to 4, characterised in that the spring members (7) are connected with their ends to the support plate (2) and to the supporting plate (6) via fastening strips (8), which are arranged spacedly in parallel with each other and perpendicularly to the casting direction.
7. A mould according to claims 1 to 6, characterised in that reinforcing strips (9) extending in the casting direction are arranged on the support plate (2) and the supporting plate (6) between rows of several leaf springs (7) arranged spacedly above one another.
8. A mould according to any one of claims 1 to 6, characterised in that flow channels (15) extending over the support plate (2) are arranged on the outside of the support plate (2) in the upper and lower areas thereof, which flow channels (15) are connected via recesses in the support plate (2) with cooling channels for cooling the copper plates (1) and comprise connections (14) for the supply and removal of coolants.
9. A mould according to any one of claims 4 to 8, characterised in that the support plates (2) are connected outside the flow channels (15) via fastening elements (13), which carry adjusting devices (5) for the narrow sides (3) for setting different casting widths.
10. A mould according to claims 1 to 9, characterised in that the amount of displacement is in inverse proportion to the square of the operating frequency.
11. A mould according to any one of claims 1 to 10, characterised in that the spring members (116) are held at their ends in clamping jaws (111), which are connected by means of clamping screws (115) passing through the spring members with brackets forming bearing surfaces located on the support plate or supporting plate.
12. A mould according to claim 11, characterised in that the clamping faces of the clamping jaws (111) - when viewed in cross-section - are circular bores, in that clamping members (112) formed of cylinder portions are arranged therein which - when viewed in cross-section - each comprise a semicircular face lying against the inner bore wall and a flat face facing the spring members, in that one or more spring member(s) (116) is(are) arranged between the clamping members (112), which spring members (116) are held at a distance from each other by one or more spacers (114).
13. A mould according to any one of claims 11 or 12, characterised in that the clamping members (112) and the spring members (116) comprise bores running perpendicularly to the longitudinal axis of the spring members (116) and in that the clamping members and the spring members are connected by fitting sleeves (113) forced through the bore, through which fitting sleeves (113) are passed the clamping screws (115).
14. A mould according to any one of claims 11 to 13, characterised in that the external diameter of the fastening screws (115) is smaller than the internal diameter of the fitting sleeve (113), such that a space is present between the two.

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