MACHINE FOR MANUFACTURING CONTINUOUS BARS OF NONFERROUS METAL BY CONTINUOUS CASTING

Abstract

A machine for manufacturing continuous bars of nonferrous metal by continuous casting includes a movable casting shell, composed of segments arranged in succession, each one having a portion defined, with a bottom and flanks, of the casting shell, and open on the sides directed toward the contiguous segments. The contiguous segments are movable along a closed path that has a substantially rectilinear portion at the casting region. Along the portion, the segments are substantially aligned and define a portion of the casting shell, with bottom and flanks, which is continuous, substantially rectilinear and closed, for at least one portion of the path downstream of the casting region, by a closure component.

Claims

1. A machine for manufacturing continuous bars of nonferrous metal by continuous casting, which comprises a movable casting shell composed of a plurality of segments arranged in succession, each one having a portion defined, with a bottom and flanks, of said casting shell, and open on sides directed toward the plurality of segments; said segments being movable along a closed path that has a substantially rectilinear portion at a casting region; along said portion of path, said segments being substantially aligned and defining a portion of the casting shell, with bottom and flanks, which is continuous, substantially rectilinear and closed, for at least one portion of a path downstream of the casting region, by closure means at its a side that lies opposite with respect to the bottom; downstream of said substantially rectilinear portion, said path of the segments having a change of direction for a progressive disengagement of said casting shell from a metal bar produced by solidification of the metal in the casting shell; said closure means comprising a belt which extends along a closed path and is supported by corresponding supporting means, means being provided for pressing a substantially rectilinear portion of said belt, which faces said substantially rectilinear portion of the path of the segments, against a side of said segments that is opposite with respect to their bottom, wherein said means for supporting the belt comprise at least two supporting rollers and at least one tension roller, which have mutually parallel axes that are oriented substantially at right angles to said substantially rectilinear portion of the path of the segments, said supporting rollers being mounted in a fixed position on a same beam which extends substantially parallel to said substantially rectilinear portion of the path of the segments.

2. The machine according to claim 1, wherein said pressing means are mounted on said beam.

3. The machine according to claim 1, wherein said tension roller engages said belt externally to said portion of the belt that faces said substantially rectilinear portion of the path of the segments, said tension roller being supported by an arm which is pivoted to a branch of said beam about a pivoting axis which is substantially parallel to the axis of said tension roller, said arm being rotatable on command about said pivoting axis in order to increase or reduce the tension of said belt along its path.

4. The machine according to claim 1, wherein said belt extends along a path that has a substantially triangular shape with the vertices defined by said two supporting rollers and by said tension roller.

5. The machine according to claim 1, wherein said pressing means of said belt comprise a plurality of rollers or sliders that are mounted on said beam and are pressed elastically against the side of said belt that is opposite with respect to said segments along the portion of said belt that faces said substantially rectilinear portion of the path of the segments.

6. The machine according to claim 1, wherein said beam can move on command toward or away from said substantially rectilinear portion of the path of the segments.

7. The machine according to claim 1, wherein said beam is connected to a fixed supporting structure by way of an articulated parallelogram.

8. The machine according to claim 1, wherein, along said substantially rectilinear portion of the path of the segments, said casting shell has its an opposite side with respect to the bottom directed upward.

9. The machine according to claim 1, wherein said substantially rectilinear portion of the path of the segments extends at an angle of at least 3° downward along the advancement direction of said segments along the corresponding path; a point of introduction of the molten metal into said casting shell being arranged proximate to a top of said substantially rectilinear portion of the path of the segments, said belt facing with the substantially rectilinear portion of the belt subtended between said two supporting rollers above said substantially rectilinear portion of the path of the segments.

10. The machine according to claim 1, further comprising means for cooling said segments and said belt along said substantially rectilinear portions of the corresponding mutually facing paths.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further characteristics and advantages of the disclosure will become better apparent from the description of a preferred, but not exclusive, embodiment of the machine according to the disclosure, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

[0024] FIG. 1 shows a continuous casting machine of the Track and Belt type, provided according to the prior art;

[0025] FIG. 2 schematically shows a machine according to the disclosure; and

[0026] FIG. 3 is an enlarged schematic cross-section view of FIG. 2, taken along the line III-III.

DETAILED DESCRIPTION OF THE DRAWINGS

[0027] With reference to FIGS. 2 and 3, a machine according to the disclosure, generally designated by the reference numeral 1, comprises a moveable casting shell 2.

[0028] The casting shell 2 is composed of a plurality of concatenated segments 3, which are arranged in succession and which can move along a path that has at least one rectilinear portion 4 at the casting region 5.

[0029] FIG. 3 shows that, in each one of the segments 3, a portion is defined with a bottom 3a and flanks 3b, 3c of the casting shell 2, which is open on its sides directed toward the contiguous segments 3 as well as on its opposite side with respect to the bottom 3a.

[0030] Along the portion 4, the segments 3 are substantially aligned and define a portion of the casting shell 2. Such portion of the casting shell 2 is movable, continuous, and rectilinear and it is closed, for a portion thereof downstream of the casting region 5, by closure means 6 at its side that is opposite with respect to the bottom 3a of the various segments 3 that make it up.

[0031] Downstream of the portion 4, the path of the segments 3 undergoes a change of direction that causes the progressive disengagement of the casting shell 2 from the bar 7 deriving from the solidification of the metal in the casting shell 2.

[0032] Conveniently, the segments 3, at the portion 4, have their side, opposite with respect to the bottom 3a, directed upward.

[0033] The portion 4 extends slightly inclined by at least 3° downward according to the direction of advancement 40 of the segments 3 along the corresponding path.

[0034] In more detail, the segments 3 are connected to the links 8 of a chain 9, closed, which is wound on at least two pinions 10a, 10b with horizontal and mutually parallel axes, which are supported by the fixed supporting structure 11 of the machine.

[0035] The portion 4 of the path of the segments 3 is defined by the upper branch of the chain 9 which extends between the pinions 10a, 10b. The pinion 10a can be actuated with a rotary motion about its own axis, in a way that is known per se, in order to produce the advancement of the chain 9 and therefore of the segments 3 along the path defined by the chain 9, while the other pinion 10b is conveniently braked so that the segments 3, along the portion 4, are pressed up against each other.

[0036] The links of the chain 9 are articulated to each other by way of pins 12 the axes of which are parallel to the axes of the pinions 10a, 10b which mesh with the central region of the pins 12.

[0037] Conveniently, along the portion 4 of the path of the segments 3, there are means for supporting and guiding the chain 9 that carries the segments 3.

[0038] More specifically, on the pins 12, proximate to their axial ends, laterally to the links of the chain 9 and on mutually opposite sides, two idle wheels 13a, 13b are mounted as shown in FIG. 3 and, at the portion 4, there are two tracks 14a, 14b, mutually parallel and delimited laterally by corresponding flanks 15a, 15b, on which the wheels 13a, 13b rest.

[0039] The closure means 6 of the side of the casting shell 2 that is opposite with respect to the bottom 3a comprise a belt 16, preferably made of steel, which is slightly wider than the casting shell 2 defined by the segments 3 and can move along a path that faces the portion 4 with a rectilinear portion thereof.

[0040] The belt 16 is supported by corresponding support means 17 and, on its rectilinear portion that faces the portion 4, pressing means 18 act which press it against the edges of the upper side of the casting shell 2 defined by the segments 3 along the portion 4.

[0041] According to the disclosure, the support means 17 comprise at least two supporting rollers 19a, 19b which have axes that are horizontal, mutually parallel and oriented substantially at right angles to the portion 4 of the path of the segments 3. These supporting rollers 19a, 19b are mounted in a fixed position on a same beam 20 which extends substantially parallel to the portion 4 of the path of the segments 3.

[0042] Conveniently, the pressing means 18 are also mounted on the beam 20.

[0043] More specifically, the supporting rollers 19a, 19b, the axes of which are parallel to the axes of the pinions 10a, 10b, are supported, so that they can rotate about their axes, by the beam 20 which can move toward or away from the portion 4, as will be better described below.

[0044] The belt 16 is a closed loop and is wound on supporting rollers 19a, 19b and on a tension roller 21.

[0045] The belt 16, which advances at the same speed as the segments 3, can be moved by friction by contact with the segments 3 and/or by the actuation of at least one of the supporting rollers 19a, 19b.

[0046] The tension roller 21 engages with an area of the belt 16 that is outside the portion of the belt 16 that faces the substantially rectilinear portion 4 of the casting shell 2.

[0047] The tension roller 21 is supported, so that it can rotate about its own axis, which is parallel to the axes of the supporting rollers 19a, 19b, by an arm 22 which is pivoted, about a corresponding pivoting axis 22a parallel to the axis of the tension roller 21, to a branch 20a of the beam 20. The arm 22 can rotate with respect to the beam 20 about the pivoting axis 22a, for example by the action of a fluid-operated actuation cylinder 23, in order to increase or reduce the tension of the belt 16, as shown by the dotted lines in FIG. 2.

[0048] In practice, the belt 16 extends along a closed path that has a substantially triangular shape structure, with the vertices defined by the two supporting rollers 19a, 19b and by the tension roller 21.

[0049] The pressing means 18 comprise a plurality of rollers 24 or sliders which are mounted on the beam 20 and are elastically pressed, by way of corresponding springs 25, against the side of the belt 16 that is opposite with respect to the segments 3 along the portion of the belt 16 which faces the substantially rectilinear portion 4 of the path of the segments 3.

[0050] Conveniently, the beam 20 is connected to the fixed supporting structure 11 of the machine by way of an articulated parallelogram 26 made up of a pair of mutually parallel linkages 27a, 27b which are pivoted, with one end thereof, to the fixed supporting structure 11 and, with the other end thereof, to a flank of the beam 20. The mutually parallel pivoting axes of the linkages 27a, 27b are substantially perpendicular to the axes of the supporting rollers 19a, 19b.

[0051] The rotation of the pair of linkages 27a, 27b, which causes the movement of the beam 20 parallel thereto, in the embodiment shown is obtained by way of a fluid-operated actuation cylinder 28, but it can be obtained by way of another actuator of known type.

[0052] Advantageously, there are means of cooling the metal poured into the casting shell 2, and also of the elements of the machine that come into contact with the poured metal. Such cooling means comprise a plurality of nozzles 29 for dispensing a cooling fluid (generally water) which are facing both below and laterally to the segments 3 along the portion 4, so as to strike the lower side and the flanks thereof with the cooling liquid.

[0053] The cooling means also comprise a plurality of nozzles 30 for dispensing a cooling fluid which are facing above the portion of the belt 16 that, in each instance, engages with the segments 3 along the portion 4, so as to strike the upper face of the belt 16 engaged with the segments 3 with the cooling fluid.

[0054] The portion of the casting shell 2 defined in each one of the segments 3 preferably has, in a transverse cross-section with respect to the advancement direction of the segments 3 along the path imposed by the chain 9, an isosceles trapezoid shape structure, open at the longer base.

[0055] The metal in the melted state is fed, by way of a crucible 31, proximate to the top of the portion of the path of the segments 3.

[0056] Operation of the machine according to the disclosure is similar to that of the machine described in EP1317980 B1. The metal, which is poured from the crucible 31 into the portion of the casting shell 2 defined by the segments 3 along the portion 4, progressively solidifies forming a continuous bar 7 that gradually disengages from the casting shell 2 at the end of the portion 4 of the path of the segments 3 proximate to the pinion 10b.

[0057] It is important to note that, in the machine according to the disclosure, the bores of the beam 20 in order to provide the seats of the shafts for the supporting rollers 19a, 19b and for the arm 22 that carries the tension roller 21 can all be carried out with a single placing of the beam 20, which can be made of welded steel, on an adapted boring machine. This ensures a parallelism of the axes of the supporting rollers 19a, 19b and of the tension roller 21 within the smallest possible tolerances. By virtue of this fact, it is possible to obtain a high degree of precision in the parallelism between the axes of the rollers 19a, 19b, 21 and the axes of the pinions 10a, 10b that move the casting shell 2, thus appreciably reducing the danger of infiltration of liquid metal between the belt 16 and the casting shell 2.

[0058] The preferred arrangement of the belt-tensioning rollers 24 or sliders on the beam 20 makes it possible to obtain a high level of efficacy in pressing the various regions of the belt 16 against the movable casting shell 2 and therefore to achieve a high level of reliability in the seal between the belt 16 and the casting shell 2.

[0059] In the machine according to the disclosure, the mounting and the removal of the belt 16 can be carried out in a simple manner by way of moving the beam 20 preferably by way of the articulated parallelogram 26 which ensures the maintenance of the parallelism of all the axes of the rotating elements of the machine.

[0060] The high precision achievable in providing the seats for the shafts of the supporting rollers 19a, 19b, and the fact that the belt-tensioning rollers 24 or sliders are mounted on the same beam 20 in which these seats are provided, make it possible to exactly reposition these elements and the belt 16 with each production cycle.

[0061] In practice it has been found that the machine according to the disclosure fully achieves the set aim, since it eliminates or substantially reduces the danger of distortion or fleeting of the belt, thus improving the efficacy of pressing the belt against the casting shell.

[0062] The machine, thus conceived, is susceptible of numerous modifications and variations. Moreover, all the details may be substituted by other, technically equivalent elements.

[0063] In practice the materials employed, provided they are compatible with the specific use, and the dimensions, may be any according to requirements and to the state of the art.