Supporting and guiding apparatus continuous rounds casting

A plurality of sets of three rolls are disposed around the periphery of the round continuously drawn from a mold and movable to the direction for or counter to the rounds, the sets being disposed along the drawing direction of the rounds. It is not necessary to replace the apparatus even when the size of the round is changed due to the replacement of molds, as the roll position are adjustable to the rounds.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an apparatus for supporting and guiding a 
round bar at the downstream side of the mold while the round bar is cast 
by the continuous rounds casting machine. 
2. Description of the Prior Art 
A conventional type of supporting and guiding apparatus for continuous 
rounds casting, as shown in FIG. 1 depicting the cross section thereof, is 
in such a structure that pillar-like frames 1, 1, . . . are arranged in 
positions surrounding the round bar A so that the longitudinal direction 
thereof is along the drawing direction of the round bar A and rotational 
axes of four rolls 2, 2, . . . are fixed to four pillar-like frames 
respectively so that the four rolls 2, 2, . . . may be brought into 
rolling-contact with the round bar A at four points on the periphery 
thereof. A plurality of sets of rolls each consisting of four rolls 2, 2, 
. . . as above-mentioned are provided along the longitudinal direction of 
pillar-like frames 1, 1, . . . 
In such a conventional structure as above, when the size (diameter) of a 
round bar A is changed due to the replacement of molds, a supporting and 
guiding apparatus for continuous rounds casting must also be replaced by 
the other fit one to the changed size, thereby requiring preparation of 
various kinds of supporting and guiding apparatus. For example, on the 
assumption that the kinds of sizes of round bars castable by the 
continuous casting machine are five and the number of strands is six, at 
least thirty sets of apparatus are required. In practical operation, 
however, two to three times as many sets as those required at the minimum, 
that is, 60 to 90 sets, are required for troubles and repairs of 
apparatus. This large number of sets requires a large expense for 
maintenance and management of the apparatus and a large space for storage 
thereof. 
Further, there is a problem since a long period of time for the replacement 
of apparatus is required. As an index of productivity in continuous 
casting operation, a monthly casting time rate such as 
(Net casting hour/Total hour per month).times.100 (%) is employed. The 
higher the rate, the greater the productivity. In the continuous casting 
machine for casting various sizes of round billet, which require the 
changing of the mold according to the size, it is usual that about five to 
six hours are required for changing of round bar size because of the 
replacement of supporting and guiding apparatus along with that of molds. 
This changing has been a cause of low level of the abovesaid monthly 
casting time rate. 
Further problem is that spaces for setting sprays for cooling the round bar 
are insufficient since rolls are mounted on four pillar-like frames 
disposed around a round bar. Accordingly, almost no gaps are provided 
between the frames, rolls, and round bar for setting the sprays. 
Moreover, a dummy bar used in the beginning of continuous casting is 
attended by a problem as follows: 
A dummy bar is roughly divided into three parts, one being a head to 
prevent the molten metal from flowing out from the mold at the start of 
molten metal pouring and to serve as a connecting part with a round bar to 
be cast and the other being a common part and a transition part for 
drawing the head in the direction of drawing of the bar. In the 
conventional apparatus, the transition part must have a diameter which is 
the same as diameter of the billet and is sufficiently as long to reach 
the lowermost end of the supporting and guiding apparatus because rolls 
are fixed so as to surround a round bar from four directions. 
OBJECT OF THE INVENTION 
The present invention was initiated in view of the above problems and a 
first object thereof is to provide a supporting and guiding apparatus for 
continuous rounds casting without requiring the replacement of apparatus 
even when the size of round bar cast by continuous casting machine is 
changed. 
A second object of the present invention is to provide a supporting and 
guiding apparatus for continuous rounds casting which can serve for 
reducing a required number of sets thereof per set of continuous casting 
machine. 
A third object of the present invention is to provide a supporting and 
guiding apparatus for continuous rounds casting intending to raise 
productivity in continuous casting operation by enabling cutting of time 
required for changing of the round bar size cast by continuous casting 
machine. 
A fourth object of the present invention is to provide a supporting and 
guiding apparatus for continuous rounds casting which can afford ample 
spaces permitting installation of sprays for cooling the round bar cast by 
continuous casting machine. 
A fifth object of the present invention is to provide a supporting and 
guiding apparatus for continuous rounds casting which permits reduction of 
the size of the transition part of dummy bar and extension of the common 
part of dummy bar. 
The above and further objects and features of the invention will more fully 
be apparent from the following detailed description with reference to 
accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention will be described with reference to drawings showing 
an embodiment thereof. 
FIG. 2 is a schematic side view of a supporting and guiding apparatus for 
continuous rounds casting of the present invention, in which a mold M and 
a round bar A cast by the mold M and drawn therefrom are shown, FIG. 3 
being a schematic cross sectional view thereof. 
An apparatus of the present invention is in such a structure that 
stationary rolls 3, 3, . . . and movable frames 6, 6 are fixed to the 
stationary frame 9 positioned immediately below the mold M and movable 
rolls 4, 4, . . . and 5, 5, . . . are fixed to the abovesaid movable 
frames 6, 6. 
The stationary frame 9 is formed in the shape of channel so that the 
lengthwise direction thereof (the direction shown by an arrow mark in FIG. 
2 and along which the round bar A is drawn) is adapted to run from top to 
bottom and the open part thereof is directed to the center of radius R of 
curvature of the continuous casting machine (to the center of curvature of 
the round bar A). A part of the stationary frame 9 opposite to the open 
part thereof (a part opposite to the outside of curvature of the round bar 
A) is provided with a plurality of stationary rolls 3, 3, . . . disposed 
in the vertical direction. 
On the other hand, movable rolls 4, 4, . . . and 5, 5, . . . are fixed to 
the movable frames 6 and 6 fixed to the stationary frame 9. On the rear 
side of the surface of each movable frame 6 opposite to the round bar A, 
guide rods 7 and 7 are erected, and a screw-threaded lever 10a of moving 
means 10 is erected in the mid-position between both guide rods 7 and 7. 
On either side of the stationary frame 9, two guide bushes 8 and 8 are 
mounted together with a handle 10b of moving means 10 to be disposed in 
the mid-position between these guide bushes 8 and 8. The handle 10b is 
provided with a screw-threaded hole and operates to move the guide bushes 
8 through a handle holder or guide bush support 81. Both guide rods 7 and 
7 are respectively inserted through both guide bushes 8 and 8, the 
threaded lever 10a being inserted through the threaded hole of the handle 
10b. On the surface of each movable frame 6 opposite to the round bar A, a 
plurality of movable rolls 4, 4, . . . (or 5, 5, . . . ) are mounted along 
the vertical direction. 
An angle for setting the guide rods 7 and 7 to the movable frame 6 and that 
for setting the guide bushes 8, 8 to the stationary frame 9 are 
determined, as shown in FIG. 3, so that the surface of the stationary 
frame 9 to which stationary rolls 3, 3, . . . are fixed and the surfaces 
of both movable frames 6 and 6 to which movable rolls 4, 4, . . . and 5, 
5, . . . are fixed each lie on each side of a regular triangle. Rotating 
shafts of stationary rolls 3, 3, . . . are fixed to the stationary frame 9 
in the direction parallel with the surface of the stationary frame 9 
facing the round bar A and perpendicular to the drawing direction of the 
round bar A whereas rotating shafts of movable rolls 4, 4, . . . and 5, 5, 
. . . are fixed to movable frames 6, 6 in the directions parallel with the 
surfaces of movable frames 6 and 6 facing the round bar A and 
perpendicular to the drawing direction of the round bar A. 
Thus, rolling-contact surfaces of a set of three rolls, that is, stationary 
one 3 and movable two 4 and 5, lying roughly on a plane perpendicular to 
the drawing direction of the round bar A, as shown in FIG. 3, constitute 
three sides of a regular triangle circumscribed around the outer periphery 
of the round bar A. 
In the apparatus of the present invention constructed as above, both 
movable frames 6 and 6 are moved by turning the handle 10b of moving means 
10 manually. Alternatively, a suitable power driven driving means may be 
utilized. At this time, both movable frames 6 and 6 and accordingly 
movable rolls 4, 4, . . . and 5, 5, . . . mounted thereon are moved in 
parallel translation, as shown in FIG. 3 indicating positions of movable 
rolls 4 and 5 by alternate long and two dashes lines, because an angular 
relation between the movable frame 6 and guide rods 7, 7 and that between 
the stationary frame 9 and guide bushes 8, 8 are fixed as described above. 
Therefore, an angular relation between three rolls 3, 4 and 5 is not 
varied even with the movement of movable rolls 4 and 5. In other words, 
rolling-contact surfaces of three rolls 3, 4 and 5 constitute three sides 
of a regular triangle which are always in contact with the outer periphery 
of the round bar A regardless of the size of round bar A. 
In this way, the supporting and guiding apparatus of the present invention 
exactly supports, guides, and positions the round bar A even when the size 
(diameter) of the round bar A drawn from the mold M is changed. 
Also, in this apparatus of the invention, considerably wide gaps are 
provided between rolls arranged along the drawing direction of the round 
bar A and thereby annular cooling sprays can easily be installed in these 
gaps so as to surround the round bar A. 
Guiding of movable frames 6 and 6 depends on the guide rods 7, 7 and guide 
bushes 8, 8, however, other various types of guiding mechanism or link 
mechanism may be used. A hydraulic cylinder or the like may be used as 
moving means. 
Bearing 11, 12 and 13 used for rolls 3, 4 and 5, respectively, may be of 
any type so far as permitting smooth revolution of rolls 3, 4 and 5. 
In FIG. 3, three rolls 3, 4 and 5 are disposed in three positions spaced 
from each other at equal angular intervals, however, intervals are not 
necessarily equal. 
When applying a dummy bar, a transition part of dummy bar connected at 
lower end of dummy bar head which is inserted into the mold is not 
necessary. A common part of dummy bar larger in outer diameter than the 
dummy bar head can be extended as long as reaching a position immediately 
below the mold after inserted through the apparatus of the present 
invention. That is to say, an operation may be performed in such a way 
that, at the start of use of a dummy bar, movable rolls 4 and 5 are kept 
withdrawn so as not to interrupt movement of the common part of dummy bar 
and, as casting starts and the head enters the supporting and guiding 
apparatus of the invention to pass therethrough, are moved to appropriate 
position relative to the dummy bar head. Thus, the common part of dummy 
bar can be greater in length than that used in the conventional supporting 
and guiding apparatus. 
Further, in this embodiment, a stationary roll 3 and movable rolls 4 and 5 
fixed to a stationary frame 9 and movable frames 6 and 6 respectively, are 
disposed in four steps spaced from each other at pitches l along the 
drawing direction of the round bar A and movable rolls 4 and 5 are moved 
in company with the movement of the movable frames 6 and 6. However, for 
effectively satisfying the above purpose, it is possible to provide each 
of movable rolls 4, 4, . . . and 5, 5, . . . with moving means so that 
each roll may independently be moved (FIG. 6). 
As this invention may be embodied in several forms without departing from 
the spirit of essential characteristics thereof, the present embodiment is 
therefore illustrative and not restrictive, since the scope of the 
invention is defined by the appended claims rather than by the description 
preceding them, and all changes that fall within meets and bounds of the 
claims, or equivalence of such meets and bounds thereof to be embraced by 
the claims.