FR2686279A1 - DEVICE FOR CONTINUOUS CASTING BETWEEN CYLINDERS OF A METAL PRODUCT. - Google Patents

Abstract

The casting device comprises two counter-rotating cylinders with parallel axes (1, 2) and two fixed side walls (4) resting on the axial ends of the cylinders (1, 2), defining a casting space (3) between the cylinders ( 1, 2). Each of the side walls (4) comprises two plates (5, 6) which are each in rubbing contact with a flat front face of one of the cylinders (1, 2) and at least one complementary wall (9, 10) interposed between the two plates (5, 6) and between the cylinders (1, 2). The cylinders (1, 2) comprise on their end faces an annular groove (19, 20) having as its axis the axis of the cylinder, in a zone in contact with a plate (5, 6). A lubricant is introduced into the throat (19, 20). Preferably, the metal plates (5, 6) comprise an annular rib (23, 24) engaged in the groove (19, 20) ensuring the radial positioning of the plates (5, 6).

Description

The invention relates to a device for continuous casting between cylinders of a

  metallic product More specifically, the invention relates to means for maintaining and / or lubricating the side walls of the continuous casting device delimiting the space for

casting between the cylinders.

  We know continuous casting devices

  of a metallic product and in particular of a metallic strip

  that thin comprising two counter-rotating cylinders with horizontal and parallel axes arranged opposite with a

  spacing corresponding to the thickness of the product to be poured.

  The liquid metal is poured into a casting space defined by the portions of the surfaces of the cylinders

  located above a plane passing through the parallel axes

  the of these cylinders and by lateral side walls

  fixed mites called small faces resting on the ends

axial mites of the cylinders.

  The small faces must be applied against the axial ends of the cylinders, so as to obtain an effective seal to prevent any leakage of metal

in fusion.

  It is also necessary to avoid or limit the solidification of the metal in contact with the side walls. To avoid solidification of the metal in contact with the side walls, it has been proposed to produce these walls in a thermally insulating material, so as to prevent the cooling of the molten metal in contact

side walls.

  However, it has proven very difficult to

  maintain both good thermal insulation characteristics and sufficient mechanical resistance of the walls In particular, the wear resistance of the insulating walls is generally insufficient to ensure

  long casting time without changing the walls.

  We therefore proposed, for example in the request

  French patent 90-11000, to use side walls

  comprising a part of heat-resistant refractory material

  insulating element inserted between the cylinders and placed between two metal plates in the form of disc portions having a frustoconical edge, in contact

  rubbing each with a flat front face of the cylinder.

  The metal plates have an edge of circular shape on each of their faces delimiting the large base or the small base of the frustoconical edge of the plate, due to the frustoconical shape of the edge of the plate The face comprising the edge of larger radius of curvature delimiting the large base is placed in contact with a cylinder, so as to be superimposed on the edge

  In this way, the liquid metal fills

  sant the casting space comes into contact, at the level of the small faces, only with the pieces of refractory material

  insulation inserted between the metal plates.

  It is therefore necessary to maintain the metal plates in a perfectly defined position relative to the cylinders, throughout the casting, taking into account that the cylinders are liable to expand radially and in the direction of their axes or

  still to deviate or to approach in directions

radial tions.

  In addition, it may be difficult to obtain perfect alignment of the front faces of the two cylinders, due to the precision of adjustment and machining of the cylinders.

  Finally, it can be difficult, before starting

  rage of the casting device, to make the adjustment of the small faces, so that the edges of the metal plates of these faces are in coincidence

  perfect with the edge of the cylinders.

  On the other hand, the fact that the metal lateral parts of the small plate-shaped faces are

  in rubbing contact with the cylinders generally requires-

  ment to introduce a lubricant between the rubbed surfaces

  aunts, to limit their wear. It has been proposed to introduce the lubricant which may consist of grease into cavities machined in the metal parts of the small faces. This method of proceeding has a drawback in that the cavities which may consist of grooves are

  performed on a consumable part which must be replaced

  created after a relatively short usage time.

  In addition, the metal parts of the small faces are not held and centered so

efficient compared to cylinders.

  The object of the invention is therefore to propose a device for the continuous casting of a metallic product comprising two counter-rotating cylinders with parallel axes arranged opposite each other with a certain spacing and two fixed lateral walls, or small faces, in abutment on the axial ends of the cylinders, delimiting a casting space between the cylinders and each comprising two plates which are in rubbing contact each with a flat front face from one of the two cylinders to one of the

  axial ends of the cylinders and a complementary wall

  shut up between the two plates and between the

  cylinders, this device ensuring lubrication

  effective cation of the rubbing surfaces between the small faces and the cylinders and keeping the plates of the small faces in a very precise position relative to

to the cylinders.

  For this purpose, the cylinders have on each of their front faces, an annular groove having the axis of the cylinder axis, in an area in contact with one of the plates of a small face, so that the plate and the groove cooperate during the rotation of the cylinder, to maintain and / or lubricate the

small face.

  In order to clearly understand the invention, a description will now be given, by way of nonlimiting example, with reference to the attached figures, of a device for

  continuous casting of a metal strip according to the invention.

  Figure 1 is a partial sectional view through

  a horizontal plane along 1-1 of FIG. 2 of an arrangement

  sitive of continuous casting according to the invention and according to a

first embodiment.

  Figure 2 is a sectional and elevational view

according to 2-2 of figure 1.

  Figure 3 is a side view of a plate of the

  continuous casting device according to 3 in FIG. 2.

  Figure 4 is a partial sectional view through a horizontal plane of a continuous casting device

  according to the invention and according to an alternative embodiment

  tion. Figure 5 is a partial sectional view along 5- 5 of Figure 6 of a continuous casting device according to the invention and according to a second embodiment. Figure 6 is a front view of the device

  of casting, according to 6-6 of figure 5.

  In Figures 1 and 2, we see a device for

  continuous casting between cylinders which has two cylinders

  dres 1 and 2 having axes parallel to each other and hori-

  zontals and which are arranged with a certain spacing

  corresponding to the thickness of the product to be poured.

  In FIG. 1, the device has been represented in section by a horizontal plane passing through the axes of the

cylinders 1 and 2.

  During casting, the cylinders 1 and 2 are rotated in opposite directions and liquid metal is introduced into a casting space 3 delimited by the side surfaces of the cylinders arranged opposite and by two side walls such that the wall 4, called small faces, which bear on the axial ends of the cylinders 1 and 2. The casting space 3 has a minimum width corresponding to the spacing of the cylinders 1 and

  2 and to the thickness of the cast product, in the horizontal plane-

  tal containing the axes of cylinders 1 and 2.

  Cylinders 1 and 2 are internally cooled-

  and ensure the solidification of the liquid metal introduced into the casting space 3, so that solidified metal skins are formed in contact with the surface of the cylinders 1 and 2 which entrain the solid metal liquid towards the part of narrower width of the casting space 3, or neck, at

  which the solidified skins meet.

  The solidified product is continuously extracted in

below the cylinders.

  The small faces such as the face 4 are intended to seal the pouring space 3 on its lateral sides in a leaktight manner, so as to prevent any

liquid metal infiltration.

  Cylinders 1 and 2 have a metallic core

  that steel central la (or 2 a) and an external copper ferrule lb (or 2 b) comprising channels, not shown, in which a liquid such as water is circulated during pouring, to ensure the cooling of the corresponding ferrule lb (or 2 b) which comes into contact with the liquid metal introduced into the space of

casting 3.

  Small faces such as face 4,

  tent two plates, preferably metallic, 5 and 6 having the shape of annular sectors, as it is

visible in Figure 2.

  The plates 5 and 6 which are fixed and which come

  contact in frictional contact with the external peripheral part of the cylinders comprising the cooled ferrules 1b and 2b could also have the shape of disc portions, as described in patent application 90-11000. The plates 5 and 6 are preferably made of steel but can also be made of other metals or even of non-metallic material. They have an external edge of frustoconical shape, the largest diameter of which is equal to the diameter of the cylinders 1 and 2 L '. edge 7 or 8 of the metal plate 5 or 6 located at the end of the frustoconical edge having the largest diameter is

  arranged in coincidence with the edge of the corresponding cylinder

laying 1 or 2.

  The closing of the casting space 3, between the cylinders 1 and 2, is ensured by two pieces of material

  refractory 9 and 10 which have frustoconical bearing surfaces

  whose shape corresponds to the shape of the frustoconical edge

  as plates 5 and 6, which are brought together against one another on a flat face and which are interposed

  between the metal plates 5 and 6.

  The refractory pieces 9 and 10 are held inside a housing 12 which allows the small face 4 to bear against the axial ends

  corresponding to cylinders 1 and 2.

  The housing 12 has an external edge directed towards the plates 5 and 6 and separated from these plates by a clearance avoiding any contact between the housing 12 and the plates 5 and 6 There is no direct mechanical connection between the housing 12 and the plates 5 and 6, the

  small face 4 being kept in contact with the extremi-

  axial tees of the cylinders 1 and 2, by means of helical springs 14 interposed between the interior surface of the housing 12 and pressure plates 15 coming into contact with an external flat surface of the

  pieces of refractory material 9 and 10.

  In addition, helical springs 16 distributed around the housing 12 and interposed between the housing and support parts 17 in contact with the edge of the refractory parts 9 and 10 allow these parts to be held firmly against each other, according to their bearing faces. By exerting a bearing force on the housing 12, in the axial direction of the cylinders 1 and 2, the bearing of the refractory pieces 9 and 10 is carried out on the metal plates 5 and 6 and the bearing of the metal plates 5 and 6 on the outer end parts

cylinders 1 and 2.

  According to the invention, the cylinders 1 and 2 comprise

  tent annular grooves 19 and 20 machined inside of annular parts 21 and 22 attached to the faces

front of the ferrules lb (or 2 b).

  The grooves 19 and 20 have for axis the axis of the

corresponding cylinder 1 or 2.

  As can be seen in FIGS. 1 and 3, the metal plates 5 and 6 have on their faces directed towards the corresponding cylinder 1 or 2, a rib in the form of an annular sector 23 or 24 whose width is substantially identical to the width of the groove 19 (or 20), so that the annular rib 23 or 24 penetrates inside the corresponding groove, in the service position of the small face, as shown

in figure 1.

  As can be seen in FIG. 3, the annular rib 23 of the metal plate 5 has two end parts 23 a and 23 b, the shape of which corresponds

  substantially to the shape of the section of the groove corresponding to

  laying 19 and an intermediate part 23 c having a height less than the height of the parts 23 a and 23 b In this way, a free space is provided, inside the groove 19, between the parts 23 a and 23 b, when the

  metal plate 5 is fixed in position against the end

front half of cylinder 1.

  This free space delimited by the parts 23 a and 23 b inside the groove 19 makes it possible to constitute a reserve of grease ensuring the lubrication of the surfaces

  rubbing of the metal plate 5 and of the cylinder 1.

  In particular, this ensures lubrication of the friction surfaces of the annular rib 23 and of

throat 19.

  The rib 24 of the metal plate 6 comprises

  a profile identical to the profile of the rib 23 of the plate

  that 5; the plate 6 is lubricated by introducing grease between the end parts of

the rib.

  As a variant, it is possible, as shown in FIG. 1, to provide guide and holding ribs 23 and 24 of the metal plates 5 and 6 whose height is less than the depth of the

corresponding groove 19 or 20.

  A free space is thus provided at the bottom of the groove 19 or 20 and this free space can be supplied with a lubricant such as oil through a pipe 25 or 26 passing through the support pieces 17 and the metal plates 5 and 6 to lead into free space at

throat 19 or 20.

  In this way, a lubricant can be ensured.

  continuous rubbing surfaces of plates 5 and 6

and cylinders 1 and 2.

  The annular ribs 23 and 24 introduced into the grooves 19 and 20 make it possible to ensure extremely efficient positioning, centering and holding in position of the plates 5 and 6, during casting, so

  that the outer edge 7 or 8 of the plates 5 or 6 is now

  naked in perfect alignment with the edge of the cylinder

corresponding 1 or 2.

  This arrangement also makes it possible to achieve perfect alignment of the sides of the two cylinders 1 and 2 which may have slight dimensional differences due to the precision of the machining and of the adjustment,

during assembly.

  When the cylinders expand during the

  casting or during a horizontal displacement of these cylin-

  dres, the metal plates 5 and 6 of the small face 4 keep their initial positioning relative to the cylinders 1 and 2, so that the small face remains

perfectly waterproof.

  In the case where cylinders 1 and 2 move

  relatively to each other in a direction perpendicular to

  laire to their axis, this displacement can result, in the case of a spacing of the cylinders, by a slight spacing of the parts 9 and 10 and by an infiltration and a freezing of the steel between the parts in refractory material 9 and

10.

  The use of two refractory pieces

  worn one against the other instead of a single piece

  thus allows a slight spacing of the cylinders.

  On the other hand, in the case of a displacement of the

  cylinders resulting in their approximation, this displacement

  cement can only be accommodated if the material of the refractory piece or pieces interposed between the plates 5 and

  6 is likely to accept some compression.

  As can be seen in FIG. 2, the ends of the annular sectors constituting the metal plates 5 and 6, in the direction of rotation of the corresponding cylinder 1 or 2, are supported on fixed stops

  27 and 28 which avoid rotational training

  tion of the metal plates 5 and 6 by the cylinders 1 and 2. The stops 27 and 28 have no role with regard to the radial positioning of the metal plates and 6 relative to the cylinders 1 and 2. In FIG. 4, shows an alternative embodiment of a small face 4 'of a continuous casting device between cylinders according to the invention, making it possible to accommodate a certain displacement of the cylinders 1' and 2 '

  one in relation to the other resulting in a rapprochement-

ment of their axes.

  The metal plates 5 ′ and 6 ′ of the small face 4 ′ have, like the plates 5 and 6 of the small face 4 shown in FIG. 1, ribs in the form of portions of rings introduced into grooves machined in the ends fronts of the corresponding cylinders

1 and 2 '.

  The metal plates 5 ′ and 6 ′ further comprise two frustoconical faces 5 ′ a and 6 ′ a inclined in the direction of the casting space 3 ′ on which bear corresponding frustoconical faces of two

  pieces of refractory material 9 'and 10'.

  The pieces 9 'and 10' of refractory material are held in abutment against the plates 5 'and 6' and

  brought together against each other by springs.

  In the case of a relative displacement of the cylin-

  dres 1 'and 2' resulting in a bringing together of their axes, the surfaces 5 'a and 6' have metal plates 5 'and 6' linked to the cylinders during their displacement move by sliding on the frustoconical faces of

  pieces of refractory material 9 'and 10'.

  In FIGS. 5 and 6, a second embodiment of a continuous casting device according to the invention is shown, making it possible to ensure a

  effective lubrication of metal plate surfaces

  only small faces and axial ends of

cylinders, during casting.

  il The continuous casting device generally designated by the reference 30 shown in Figures 5 and 6 comprises two counter-rotating cylinders 31 and 32 arranged with a certain spacing so as to delimit between them a casting space 33 which is closed

  at its ends by side walls such as 34.

  The wall 34 consists of two metal plates 35 and 36 in the form of annular sectors having a frustoconical edge which are pressed against the front faces of the cylinders 31 and 32 and by a piece of refractory material 37 interposed between the

metal plates 35 and 36.

  During casting, the metal plates 35 and 36 are in rubbing contact with the external part of the

  cylinders 31 and 32 which rotate in opposite directions.

  According to the invention, the cylinders 31 and 32 have grooves 39 and 40 of annular shape having

  for axis the axis of the corresponding cylinder 31 or 32.

  A lubricant is introduced into the grooves 39 and 40, in the form of a grease filling these grooves or in the form of a liquid flow introduced into the

grooves 39 and 40 during casting.

  The grooves 39 and 40 are machined in a part

  front faces of cylinders 31 and 32 which is overlapped

  green by the metal plates 35 and 36 The faces of the metal plates 35 and 36 coming into contact with the front faces of the cylinders 31 and 32 cooperate with the groove 39, during the rotation of the cylinders 31 and 32, to ensure distribution and distribution of

  lubricant between the metal plate and the cylinder.

  In the case of the use of a low viscosity lubricant, for example a liquid lubricant, it may be necessary to have fixed closure plates 41 and 42 in contact with the front faces of the

  cylinders 31 and 32, in the parts of these front faces

  which are not covered by the metal plates

  ques 35 and 36 One thus realizes a complete closure of the grooves 39 and 40 ensuring the distribution of lubricant between the friction surfaces of the cylinders 31 and 32 and of the plates 35 and 36 supported on these front faces. The plates 41 and 42 can be constituted by discs or by rings covering the grooves

39 and 40.

  In the case of the second embodiment shown in FIGS. 5 and 6, the grooves 39 and 40 do not have the function of ensuring the positioning and the maintenance of the metal plates 35 and 36 of the small faces, by cooperation of a annular rib and

gorges 39 and 40.

  The device according to the invention although of a simple structure makes it possible to appreciably improve the

casting conditions.

  In particular, the wear of the friction parts

  can be greatly reduced.

  The invention is not limited to the embodiments

which have been described.

  One can imagine devices comprising

  metal plates bearing on the front faces

  the cylinders of a shape different from those which have been described between which one or

  several additional pieces of refractory material.

  We can imagine other arrangements of the small faces to accommodate a movement

  relative of the cylinders by spacing or by approximation.

  The invention applies not only to continuous casting between cylinders of thin metal strips but

  still at continuous casting between cylinders of any pro-

metallic duit.

Claims (10)

  1. Continuous casting device for a metal product comprising two cylinders (1, 2; 1 ', 2'; 31, 32) contra-rotating with parallel axes arranged opposite each other with a certain spacing and two fixed side walls ( 4, 4 ', 34) or small faces, pressing on the axial ends of the cylinders (1, 2; 1', 2 '; 31, 32) delimiting a casting space (3, 3', 33) between the cylinders and each comprising two plates (5, 6; 5 ', 6'; 35, 36)   which are in rubbing contact each with a front face   flat tale from one of the two cylinders to one of the ends   axial tees of the cylinders and at least one complementary wall   shutter (9, 10; 9 ', 10'; 37) interposed between the two plates (5, 6; 5 ', 6'; 35, 36) and between the cylinders (1, 2; 1 ', 2'; 31 , 32) characterized in that the cylinders (1, 2; 1 ', 2'; 31, 32) have on each of their front faces, an annular groove (19, 20, 39,) having as axis the axis of the cylinder, in an area in contact with one of the plates (5, 6; 5 ', 6'; 35, 36) of a small face, so that the plate (5, 6; 5 ', 6', 36 ) and the groove (19, 20, 39, 40) cooperate during   the rotation of the cylinder, to maintain and / or lubricate   fication of the small face (4, 4 ', 34).   2. Device according to claim 1, characterized in that each of the plates (5, 6) comprises a rib in the form of an annular sector (23, 24) engaged inside the groove (19, 20) of the corresponding cylinder to maintain the plate (5, 6)   in a fixed radial arrangement with respect to the cylinders dres correspondents (1, 2).   3. Device according to claim 2, characterized in that the plates (5, 6) have a circular edge (7, 8) whose diameter is identical to the diameter of the corresponding cylinder (1, 2) held in coincidence with the edge of the corresponding cylinder (1, 2), by the annular rib (23, 24) introduced into the groove (19, 20) of the cylinder (1, 2).   4. Device according to any one of   Claims 2 and 3, characterized in that the   annular rib (23) has two end parts (23 a, 23 b) whose shape and dimensions correspond to those of the groove (19) and a central part (23 c) providing a free space inside the groove (19), this free space being filled with a lubricant during the casting.   5. Device according to any one of   Claims 2 and 3, characterized in that the   annular rib (23) provides free space at the bottom   throat (19), in communication with a supply means   lubricant (25) through an opening in the crossing the plate (5).   6. Device according to any one of   Claims 1 to 5, characterized in that it   comprises two complementary parts (9, 10) of refractory material interposed between the two plates (5, 6)   of a small face (4), reported one against the other.   7. Device according to any one of   Claims 1 to 6, characterized in that each   small faces (4) comprises a housing (12) having no direct mechanical connection with the plates (5, 6) of the small face (4) inside which are placed the complementary part or parts (9, 10 ) of the small face (4), the inner wall of the housing (12) coming to bear   on the complementary part (s) (9, 10) via the   medial of elastic return means (14), so as to exert a bearing force in the axial direction of the cylinders on the complementary part or parts (9, 10) and   through them on the plates (5, 6).   8. Device according to claim 6, characterized in that elastic return means (16) are interposed between the inner wall of the housing (12) and each of the two complementary parts (9 and 10) to ensure the support l one against the other   of these complementary parts (9, 10).   9 Device according to claim 6,   characterized by the fact that the plates (5 ', 6') comprise   tent frustoconical surfaces (5 ′ a, 6 ′ a) inclined in the direction of the pouring space (3 ′) and that the two complementary parts (9 ′, 10 ′) have corresponding surfaces capable of moving by sliding on the surfaces (5 ′ a, 6 ′ a) of the plates (5 ′, 6 ′), when moving close together in one direction   perpendicular to their axis, cylinders (1 ', 2').   10. Device according to claim 1, characterized in that the grooves (39, 40) of the cylinders (31, 32) are connected to a lubricant supply means and that the device further comprises fixed plates (41, 42) closing the grooves (39, 40) bearing on the front faces of the cylinders (31, 32), outside the areas on which the wall plates   lateral (35, 36) come to bear.