EP1138419A1 - Clamping device for a refractory- made plate of a sliding gate - Google Patents

Abstract

A wedge (14) for a device for clamping a refractory plate into a housing of a slide valve of a casting installation is able to deform elastically, each of its two ends (21, 21') are able to thrust against the corresponding side of the refractory plate, when the wedge is subjected to a clamping force, and each of the two ends (21, 21') can thrust equally against an adjacent wall of the housing under the effect of a clamping force and/or the thermal dilation effect of the plate. Independent claims are included for a refractory plate assembly using this wedge, a slide valve using this assembly , a casting installation equipped with this slide valve and a method for clamping a refractory plate in the housing of the slide valve in such an installation.

Description

The present invention relates to a shim of a plate clamping device refractory in a housing of a slide valve of a casting installation, a assembly comprising a refractory plate and its housing, a slide valve comprising such an assembly, a casting installation comprising such a valve drawer and a method of clamming a refractory plate.

We know that the refractory plates that are used in the slide valves of metallurgical casting installation are mounted in their housing by clamage.

These housings can be fixed elements of the valve frame, when it comes to fixed plates or carriages in the case of movable plates of slide valves.

The clamping is generally carried out using a block which is supported on the one hand on an edge of the plate, on the other hand on an adjustable stop which allows to clamp the wedge against the plate in order to immobilize it.

With the known shims, a satisfactory holding of the plate is obtained in its housing. However, a notable difficulty is the dispersion of shapes between plates, which may be due to their manufacturing process or may be desired for different reasons. These dispersions can unbalance the supports between the wedge and the plate and lead to the application of very high localized forces.

In the long run, these high stresses can damage both the hold and the plate, which is already prone to cracking due to its normal use.

The present invention aims in particular to provide a shim which does not have the disadvantage of known wedges.

The present invention relates to a shim of a plate clamping device refractory in a housing of a slide valve of a casting installation, said shim comprising on the one hand, a thrust zone by which it can undergo a force of tightening to push it against a refractory plate located in the housing and on the other hand, two ends each of which is suitable for pressing against an edge of the refractory plate, characterized in that the wedge is able to deform elastically and in that each of the two ends of the wedge is shaped so as to take also pressing against an adjacent wall of the housing, either under the effect of a force of appropriate clamping (and greater than the clamping force required to make so that the wedge rests only on the edges of the plate), either under the effect of the thermal expansion of the plate due to the high temperatures encountered during casting operations, or under the combined effect of these two actions.

One of the advantages of the wedge according to the invention is that it adapts automatically to the geometry of the plate that it must immobilize. So the dispersions of shapes between plates, due to their manufacturing process, do not cause no defect in the claim. Likewise, the ability of the hold to conform automatically to the supports offered by the plate, due to its elasticity, prevents it from undergoing itself too high stresses and, in the long run, to break.

In this way, thanks to its elasticity, the wedge according to the invention first absorbs itself part of the deformation of the plate due to its expansion and then carry over, during casting operations, on the plate housing the clamping forces imposed by the adjustable stop and by the deformation due to the expansion of the plate.

In other words, the wedge behaves like a self-positioning strut between the plate and its housing.

With regard to the elastic deformation of the wedge, account will be taken of following factors: advantageously, we will choose a shim whose stiffness constant is less than 10 T / mm, preferably less than 5 T / mm and in a completely preferred, of the order of 1 to 3 T / mm. These values are to be compared with those we measurement on known shims which range from 10 to 30 T / mm, or even more. Until present, we have always considered that the hold, when it is present, must have sufficient rigidity so that the plate is driven directly during the setting in motion of the drawer without allowing the appearance of the slightest play. Therefore, it is the stiffness constant of the shims in question must be at least greater than 10 T / mm, and in general, greater than 20-30 T / mm.

Departing from known principles, the inventors opted for a wedge significantly less rigid whose elasticity absorbs part of the expansion of the plate without generating significant constraints until the ends of the wedge come into contact and bear against the walls of the housing (which have generally a stiffness constant greater than 40 T / mm, or even of the order of 150 to 200 T / mm for certain pocket drawers). The wedge no longer plays the role a brace between the plate having almost reached its maximum dimension and its housing. As soon as the plate has almost reached its maximum dimension at the time where the ends of the wedge come to bear on the walls of the housing, the stresses generated at the level of the plate are very greatly reduced.

Advantageously, the wedge must not however absorb all the deformation due to the expansion of the plate so that the latter remains maintained in compression during casting operations. It is indeed beneficial that the plate is maintained in compression so that any cracks that may appear are maintained closed.

Advantageously, the shim is produced in one piece, by machining, molding or forging, in a material having the required properties, having regard to the temperature conditions, mechanical strength and elasticity of the wedge. Of examples of materials suitable for making the hold of the invention are all steels, in particular, 42CrMo4 steel.

In a particular embodiment, at least one of the two ends of the block is connected to the thrust zone by an elastically deformable portion of the block, authorizing a change of orientation of the end.

This change of orientation allows said end to apply against the plate by a surface support and thus avoids punctual tightening forces detrimental to plaque.

The second bearing surface, rounded, serves as a "ball" and allows the contact which is established between the end of the wedge and the plate to impose the orientation of said end, so that said contact is surface.

In a particular embodiment, the wedge has only one zone of thrust. The clamping force applied by an adjustable stop of the housing is distributed thus automatically between the two ends of the wedge and we avoid any imbalance between the clamping forces applied by the two ends of the shim on the plate.

Preferably, the thrust zone has a smooth face (which can be flat or rounded) for contact with the adjustable stop of the housing, which can apply its clamping force at any point on this smooth face. In this way, the hold can take its equilibrium position between the housing and the wedge, possibly by shifting by relative to the longitudinal axis of the housing due to the asymmetries of the plate, without the support between the adjustable stop of the housing and the thrust zone is not disturbed.

In a particular embodiment, at least one of the ends of the wedge comprises, in cross section, a cutout allowing said end to engage under an overhang of the housing wall.

Thanks to this overhang, the fall of the housing wedge is prevented when the plate tightening is released.

The invention also relates to an assembly of a refractory plate and its housing, in the form of a carriage or a fixed element of the valve frame, comprising a housing receiving said refractory plate, which is characterized in that the refractory plate is clamped in the housing by means of a shim as described above.

According to a particular embodiment of the invention, the carriage or the fixed element of the valve frame is provided with a clamping means for exerting the clamping force on the hold. This tightening means being constituted by a screw, an eccentric, a wedge thrust or any other variant known to those skilled in the art.

Advantageously, this tightening means is removable so that in the event of blockage in the tight position, it can easily be removed from the assembly.

The invention also relates to a slide valve of a casting installation. comprising such an assembly, as well as on a casting installation.

The present invention also relates to a method for clamping a plate in a housing of a slide valve of a casting installation, consisting of interposing a shim between the plate and an edge of the housing, said shim comprising, on the one hand, a thrust zone by which it can undergo a clamping force aimed at pushing it against a plate located in the housing and, on the other hand, two ends of which each is able to be applied against an edge of the plate, characterized in that applies a clamping force on the wedge causing its elastic deformation, until that each of the two ends of the wedge bears against the corresponding edge of the plate, preferably, until the ends of the wedge are sufficiently close to the walls of the housing to be able to support it when the plate expands under the effect of the temperature reached during casting.

• la figure 1 est une vue en coupe axiale d'une partie du fond d'un récipient métallurgique, muni d'une valve à tiroir;
• la figure 2 est une vue selon la flèche II d'un élément fixe du bâti de la valve de la figure 1,
• la figure 3 est une vue selon la flèche II du chariot mobile de la figure 1,
• la figure 4 est une vue en perspective d'une des cales des figures 1 à 3,
• la figure 5 est une vue en coupe selon V-V de la figure 3,
• la figure 6 est une vue en perspective éclatée du système de butée réglable du chariot mobile.

In order to better understand the invention, we will now describe an embodiment given by way of non-limiting example, with reference to the accompanying drawing in which:

• Figure 1 is an axial sectional view of part of the bottom of a metallurgical vessel, provided with a slide valve;
• FIG. 2 is a view along arrow II of a fixed element of the frame of the valve of FIG. 1,
• FIG. 3 is a view along arrow II of the mobile carriage of FIG. 1,
• FIG. 4 is a perspective view of one of the wedges in FIGS. 1 to 3,
• FIG. 5 is a sectional view along VV of FIG. 3,
• Figure 6 is an exploded perspective view of the adjustable stop system of the movable carriage.

In FIG. 1, the metallurgical container 1 has a bottom 2 in which is formed a pouring orifice 3. The latter has an internal nozzle 4 which passes through the bottom wall of the container and the bottom plate 6 of the valve frame. A slide valve 7 is mounted on the container, opposite the pouring orifice 3. This valve comprises two fixed upper refractory plates 8, lower 9 and a movable refractory plate 10 able to slide between the two fixed plates under the action of a jack 5. It will be noted that the Figure 1 shows a three-plate slide valve. It is understood that this also relates to two-plate devices or to devices in which a plate and another casting (tube or internal nozzle by example) form a whole.

Each of the plates 8, 9, 10 is traversed by a pouring orifice 11, 12, 13 substantially the same cross section as that of the internal nozzle. The regulation or the interruption of the casting is carried out, in a known manner, by displacement of the plate mobile 10 so as to modify the casting passage resulting from the alignment of the pouring holes of the three plates. In the example shown in Figures 2 and 3, each of the plates 8, 9, 10 is encircled. She climbed into her home by clamage using a U-shaped shim 14, as shown in FIG. 4. The clamming of the plate fixed 8 takes place in a fixed element of the valve frame (not shown), that of the fixed plate 9 in a door of the slide valve, visible in FIG. 2, and that of the plate mobile 10 in a mobile carriage shown in Figure 3. The door 15 of Figure 2 has, on its periphery, a certain number of arrangements which will not be described here because they are not necessary for understanding the invention. In his part central, the door has a hollow housing 16, substantially the same thickness as the refractory plate 9, receiving this plate as well as the shim 14.

Plate 9 has an elongated shape inscribed in a rectangle with four corners truncated as described for example in the European patent application EP 99870258.3 or in document WO 98/05451. The plate is immobilized in its housing by its four edges representing the truncated corners of the rectangle. Edges 18 and 18 'are supported against fixed stops 20 and 20', while the edges 19 and 19 'are supported by the ends 21 and 21 'of the wedge 14.

As best seen in Figure 4, each end 21, 21 'of the wedge has a first bearing surface formed by a flat internal face 22, 22 ', which bears against an edge 19,19 'of the plate, and a second bearing surface formed by a rounded face 23, 23 ', opposite the flat face 22, 22', which is intended to take support against the edge 24, 24 'of the housing 16 defined in the door 15. The rounded shape of the face 23, 23 'guarantees linear contact with the edge 24, 24' of the housing, so that no orientation of the end 21, 21 'of the wedge is favored by its support against said edge. Thus, the flat face 22, 22 ', by its contact against the flat edge 19, 19', can impose at the end 21, 21 ′ the orientation according to which this support is a support of area. Each end 21, 21 'is connected to the body of the hold by a zone of less section 34, 34 'which gives this part of the wedge better aptitude for elastic deformation, thus imposing the correct orientation of each end by compared to the plate.

In addition to this local elasticity of the wedge at its ends, the wedge 14 can also deform by spacing or bringing together its two branches, also resiliently. It can thus adapt precisely to the shape of the plate, engaging its two ends between the edge 24, 24 'of the housing and each edge 19, 19 ′, each end 21, 21 ′ orienting themselves optimally, as just described.

In Figure 3, there is shown the movable carriage 26 which supports the movable plate 10. In addition to various peripheral arrangements which will not be described here, the carriage has a housing 27 in its central part, to receive the movable plate 10 immobilized by a wedge 14. The drive in translation of the carriage is provided by a cylinder 5, the rod of which engages in a cavity 28 provided for this purpose. On the element fixed frame 15 as on the movable carriage 26, the wedge is held in the housing by its two ends, even when the plate is not tightened, thanks to a cutout 29 of each end 21, 21 'and an overhang 30, 30' secured to the edge 24, 24 'of the housing, as seen in FIG. 5. The shim 14 cannot be extracted from the housing only by sliding its two ends 21, 21 'outside the overhangs, which is impossible as long as the movable stop which pushes the wedge against the plate is in place, even when this movable stopper is not tightened.

Figure 6 provides a detailed view of an example of a movable stop. This last consists of a threaded part 31 which is embedded in a cutout 32 provided for this purpose in the edge of the housing, in the longitudinal axis of the housing. The room threaded 31 engaged in the cutout is fixed there by fixing screws 33. It can receive a clamping screw (not shown) which protrudes inside the housing and bears against the smooth outer face 25 (Figure 4) of the wedge thrust area.

Since this face 25 is cylindrical and smooth, there is no point preferential support of the screw against said face, which allows the wedge to take the most appropriate position for setting the plate, this position being only determined by the support of its ends 21, 21 'between the edges 19, 19' and the edge 24.24 '.

The unique force exerted by the clamping screw on the shim is balanced automatically between the two ends 21,21 ', ensuring the clamping of the plate in his accommodation. In another embodiment not shown, the screw could be replaced by an eccentric.

It is understood that the embodiments which have just been described are not in no way limiting and that they can receive any desirable modifications without to go beyond the scope of the invention.

References:

1.

metallurgical vessel

2.

container bottom wall

3.

pouring orifice

4.

internal nozzle

5.

cylinder

6.

fixed element of the valve frame (bottom plate)

7.

slide valve

8.

fixed top plate

9.

lower fixed plate

10.

intermediate movable plate

11.

top plate pouring hole

12.

pouring hole of the bottom plate

13.

intermediate plate pouring hole

14.

wedge

15.

fixed element of the valve frame (door)

16.

housing

17.

longitudinal axis

18.

edges of the plate in contact with the fixed stop

19.

edges of the plate in contact with the shim

20.

fixed stops

21.

wedge ends

22.

flat bearing surfaces of the wedge formed by the internal faces

23.

rounded bearing surface of the wedge formed by the external faces

24.

edges of the housing in contact with the shim

25.

thrust zone

26.

mobile cart

27.

carriage housing

28.

impression intended to receive the cylinder head

29.

cut in the hold

30.

overhangs

31.

threaded part

32.

cutting

33.

screw

34.

smaller section area

Claims (13)

Wedge of a refractory plate clamping device (8, 9, 10) in a housing (16, 27) of a slide valve (7) of a casting installation, said wedge comprising on the one hand, a thrust zone (25) by which it can undergo a clamping force aimed at pushing it against a refractory plate located in the housing and on the other hand, two ends (21,21 ') each of which is capable of being applied against an edge (19,19 ') of the refractory plate, characterized in that the shim (14) is able to deform elastically, in that each of the two ends (21,21') of the shim is shaped so to bear against the corresponding edge of the refractory plate, when the wedge undergoes a clamping force and in that each of the two ends (21,21 ') of the wedge is shaped so as to bear also against a wall adjacent to the housing under the effect of a clamping force and / or under the effect of thermal expansion of the plate. Wedge according to claim 1, characterized in that said wedge is made in one piece. Chock according to one of claims 1 or 2, characterized in that at least one of its two ends (21,21 ') is connected to the thrust zone by an elastically deformable portion of the chock, allowing a change of end orientation. Wedge according to any one of claims 1 to 3, characterized in that said wedge has only one thrust zone. Self-positioning shim of a refractory plate clamping device in a housing of a slide valve of a casting installation, characterized in that said shim has only one thrust zone and in that this thrust zone has a smooth face (25) for applying a clamping force at any point of this smooth face. Wedge according to any one of claims 1 to 5, characterized in that at least one of the ends of the wedge comprises, in cross section, a cutout (32) allowing said end to engage under an overhang (30,30 ') of the wall (24,24') of the housing. Wedge according to any one of claims 1 to 6, characterized in that at least one of its two ends comprises a first bearing surface (22, 22 ') intended to be applied against the edge (19,19 ') corresponding to the refractory plate and a second bearing surface (23,23') intended to be applied against the wall of the housing (24,24 '), and in that the first bearing surface (22, 22 ') is flat while the second bearing surface (23,23') is rounded. Assembly of a refractory plate (8, 9, 10) and a carriage (27) or of a fixed element of the valve frame (6, 15) comprising a housing receiving said refractory plate, characterized in that the The refractory plate is clamped in the housing by means of a shim according to any one of Claims 1 to 7. Assembly according to claim 8, characterized in that the carriage or the fixed element of the valve frame (6,15) is provided with a clamping means for exerting the clamping force on the shim, this clamping means being consisting of a screw, an eccentric or a thrust wedge. Slide valve of a casting installation, characterized in that said valve comprises an assembly according to one of claims 8 or 9. Casting installation between an upper metallurgical container and a container lower metallurgical plant, comprising a slide valve according to claim 10. Method for clamping a plate (8, 9, 10) in a housing of a slide valve of a casting installation, consisting of interposing a block (14) between the plate and a wall (24,24 ') of the housing, said shim comprising, on the one hand, a thrust zone by which it can undergo a clamping force aimed at pushing it against a plate located in the housing and, on the other hand, two ends (21,21 '), each of which is capable of being applied against an edge of the plate, characterized in that a clamping force is applied to the wedge, causing its elastic deformation, until each of the two ends (21,21' ) of the wedge bear against the corresponding edge of the plate and until the ends of the wedge are close enough to the walls of the housing to be able to bear there when the plate expands under the effect of temperature. Method according to claim 12, characterized in that said clamping force is applied at a single point of the shim.

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