[0001] The present invention relates to continuous casting installations of endless track
type, that is to say of a type comprising a plurality of mould blocks arranged in
two endless movable tracks, the two tracks having respective runs which extend parallel
to one another and together define a mould cavity along which, in use, the mould blocks
of the two tracks move in the same direction.
[0002] A known continuous casting installation of endless track type is shown diagrammatically
in side elevation in Figure 1 in which a plurality of mould blocks 1 are interconnected
in two vertically spaced loops, thereby forming a pair of endless tracks 2. The upper
and lower runs of the lower and upper endless tracks 2 are disposed in parallel opposed
relationship such that the opposing mould blocks 1 define a continuous mould cavity
3 whose longitudinal ends are open. In use, molten metal 4 is poured in at one end
of the mould cavity 3 and the opposing mould blocks 1 are moved in the same direction
and a casting 5 is withdrawn from the other end of the mould cavity 3. At the casting
outlet, the mould blocks 1 of the endless tracks 2 are moved apart along a respective
semicircular path and then along a respective straight path towards the pouring inlet
of the mould cavity 3. At the casting outlet, there is a support device (or so-called
knife device) 6 arranged to peel or shear the casting 5 positively away from the mould
blocks of the upper and lower endless tracks 2, and to support the casting 5 thus
sheared during its transport to subsequent treatment or handling apparatus.
[0003] The casting 5 withdrawn from the mould assembly initially has molten metal within
a solidified shell and thus does not have a sufficient degree of strength and therefore
needs support by the support device 6 immediately after the casting 5 has moved out
of contact with the mould block assembly. However, the casting outlet is initially
very narrow so that the support device 6 cannot be positioned sufficiently deeply
within the casting outlet. It follows therefore that there is a relatively long section
of the casting which still has molten metal within it and which is not supported by
the support device 6. Thus qualitative problems arise due to the fact that the casting
5 withdrawn from the mould block assembly which initially does not have a sufficient
degree of strength may be ruptured or subject to interior cracking due to bulging
caused by ferro-static pressure or may be subject to peripheral cracking by attempting
to remedy the bulging.
[0004] It is thus an object of the present invention to provide a continuous casting installation
of the type referred to above in which a large support space is defined at the casting
outlet so that a support or knife device may be inserted into the casting outlet more
deeply than previously, thereby shortening the length of the casting which is not
supported.
[0005] According to the present invention a continuous casting installation of the type
referred to above is characterised in that at the downstream end of the two runs the
paths of the mould blocks of the two tracks extend in diverging straight lines from
the points at which the two tracks begin to diverge.
[0006] Thus in the known casting installation the paths of the mould blocks are of semicircular
shape from the points at which the tracks begin to diverge which means that initially
the angle of divergence is very small indeed and thus the width of the gap between
the downstream ends of the two tracks initially increases only very slowly. However,
in the construction of the present invention the paths of the mould blocks extend
in diverging straight lines which means that the width of the gap between the tracks
increases very much more rapidly. This enables a tapered or wedge-shaped support device
to be inserted further into the gap with its surfaces adjacent to the mould blocks
than in the known installation whereby the length of the casting which remains unsupported
is extremely short.
[0007] Further features and details of the present invention will be apparent from the following
description of one preferred embodiment which is given by way of example with reference
to Figure 2 of the accompanying drawings, which is a scrap diagrammatic side elevation
of the downstream end of a continuous casting installation in accordance with the
present invention.
[0008] The installation is generally similar to that shown in Figure 1 and comprises a plurality
of mould blocks 1 connected together in upper and lower endless tracks 7 which are
maintained in vertically symmetrical relationship. A support device 6 which is provided
with a plurality of rollers 8 for engaging the casting 5 is provided at the outlet
between the two tracks at the point at which they diverge. In this embodiment, the
path or locus 9 of the mould blocks at the casting outlet for each of the upper and
lower endless tracks 7 is defined as follows:
[0009] The mould blocks 1 of the adjacent runs of the two endless tracks move parallel to
one another until they reach the point P whereafter they diverge. From the point P
the locus or path 9 becomes generally semicircular but in fact includes an initial
straight portion 9a so that as the blocks begin to diverge they are moving in a straight
line and not along a semi-circular line. Each straight portion is preferably inclined
by at least 20° and more preferably about 40° to the preceding run of the associated
endless track by the two straight portions are preferably inclined by at least 40°
and more preferably by about 80°.
[0010] It follows therefore that due to the provision of the straight sections 9a, the mould
blocks 1 move away from the casting 5 at a greater angle after the separation or starting
point P than in the known installation which increases the size of the spaces above
and below the casting 5. This enables the leading inner end of the support device
6 to be inserted further into the outlet space.
[0011] Thus in the installation of the present invention, the paths of the mould blocks
includes a straight section or portion immediately after the separation or starting
point at which the mould blocks start to move apart, that is to say start to move
along the generally semi-circular pathway at the downstream ends of the tracks, so
that the paths immediately define a relatively large angle with one another and with
the central plane of the mould cavity and the mould blocks thus rapidly moving away
from the casting on both sides. The casting outlet is thus increased in size so that
it becomes possible to insert the inner leading end of the support device 6 into the
casting outlet more deeply than previously. The distance over which the casting is
withdrawn without being supported after it ceases contacting the mould block assembly
is therefore shortened. Thus, the stability of the casting whose strength is not sufficient
at the casting outlet is improved, the operation of the continuous casting installation
is stabilised and the installation made more compact and higher quality castings can
be obtained.
1. A continuous casting installation comprising a plurality of mould blocks arranged
in two endless movable tracks, the two tracks having respective runs which extend
parallel to one another and together define a mould cavity along which, in use, the
mould blocks of the two tracks move in the same direction, characterised in that at
the downstream end of the two runs (7) the paths (9) of the mould blocks (1) of the
two tracks extend in diverging straight lines (9a) from the points (P) at which the
two tracks begin to diverge.
2. An installation as claimed in Claim 1 characterised by a support device (6) of
tapering external shape which affords a cavity for receiving and supporting a casting
(6), the support device (6) being positioned in the gap between the blocks (1) of
the two tracks at the downstream end thereof and adjacent to the blocks (1) with its
end of smaller thickness being inserted further into the gap than its other end.
