EP0035088A2

EP0035088A2 - A draft gear of the billet in continuous casting plants

Info

Publication number: EP0035088A2
Application number: EP80830056A
Authority: EP
Inventors: Ferruccio Sclippa
Original assignee: SIMAC SpA
Current assignee: SIMAC SpA
Priority date: 1980-03-04
Filing date: 1980-07-16
Publication date: 1981-09-09
Also published as: IT1141781B; EP0035088A3; IT8083328A0

Abstract

A draft gear of the billet in continuous casting plants consisting of an apparatus that includes a haulage arm (1) of the billet (17), rotating around a rotational centre (18) and driven by means of variable controlled motor being expected that the end of the arm (1) presents a hooking-up system (2) to automatically drag the billet from the position of initial casting into the casting box (11) to the unhooking position after a distance of about 90° downstream the pair of haulage rollers (16).

Description

The invention relates to a draft gear of the billet at the beginning of the casting in continuous casting plants.
Draft gears of the billet in continuous casting plants are well known in prior art. The said draft gears in continuous casting plants for the production of for example billets, blooms, slabs etc... generally consist in a mobile chain with an end plug commonly called "the false billet" movable along the continuous casting extraction pathway which is therefore destined to run along the said pathway downstream from the casting box to begin the continuous casting and then withdrawn progressively with the feeding of the downstream casting.
The haulage of the said false billet occurs normally by means of the utilisation of a draught unit placed at the beginning on the tangency of the curve, outside the cooling chamber.
The problems that must be considered in this type of plant consist mainly in the floor space required by the chain of the false billet once separated from the casting billet when it is completely withdrawn, or when moving itself to the end to allow the continuation of the said continuous casting.
As is noted, the whole of the false billet, according to the actual technique presents a considerable length (about 8-10 mt.) and so equal to 90^* of the curve plus about 1 mt. in connection of the bending radius of the casting confer- ming that the said chain occupies a remarkable lot of room in length when its extraction from its pathway is completed; in this case so as not to interfere with the casting line, the said chain must be raised, or moved sideways, or moved underneath the said pathway of the casting, or it must be made to continue in retraction sending it forward into a ground tunnel as stated before.
From this derives the fact that or a remarkable lot of room must be provided for the recuperation of the said chain for example in a ground tunnel, otherwise the need to provide the transfer of the said chain to avoid the interference with the advancement of the billet and this brings about a remarkable complication in the course of the same workings and therefore in the relative plants. The same applicant with an Italian Application on the 30. 3.1979 n. 83360 A/79 had foreseen a solution sufficiently rational for the recuperation of the chain of the already said false billet, using a winding drum the which compacts the recuperation of the chain.
However even this solution brings about a remarkable complication and the utilisation of costly systems and devices in the plant.
There is the need to bear in mind that the utilisation of the said chain is however a method of haulage other than costly subjected to a lot of use, for which if this could be eliminated, a great saving in the cost of the plant'itself and its workings could be achieved.
Also forecasted, but without a positive success, were the solutions of haulage of the billet without utilisation of the chain but with truck systems in their turn needing complicated haulage systems for which no sufficiently positive result was achieved.
The scope of this invention is the realisation of a draft gear of the billet in which the haulage chain is totally eliminated or other similar devices to achieve a plant less costly, more simple, and functional, subject to minor use and not in need of an eccessively obstructional chain.
On the base of the scopes explained above the device of the said invention consists essentially in a haulage apparatus formed by an arm rotating around a determined point of rotation fixed or mobile in.which the end of this said arm results connectable to the end plug of the continuous casting billet and is able in its rotation to drag the billet continuously formed in the casting box, with its attachment point along the casting extraction pathway to then, once arrived at the point of- finished haulage, unhook itself automatically moving itself outside the feeding pathway of the billet; being provided with drive means for driving the said arm to lead into traction and controlled feeding, the ends of the said arm hooked onto the said billet from the moment of hooking until the moment of unhooking.
One way of carrying out the invention is described in detail below with reference to drawings which illustrate only one specific embodiment in which:-

Figure 1 is a partial schematic view, on the vertical plane parallel to the continuous casting extraction pathway, of the casting plant in its pathway interesting the application of the draft gear of the billet,
Figure 2 is a schematic view of the draft gear of the billet as in figure 1 from the left side.

The figures show that the new device substitutes the said "false billet" and is a very simple one in which a haulage arm is alone and positioned on a fixed rotational haulage centre, whilst it is understood that the arm could be articulated (for example built from two arms jointed between themselves), and/or, the centre of rotation of the arm itself or of half-arms could not be fixed, for example in its turn undergo a controlled movement on a truck.
In particular from figure 1 can be noted that the haulage arm is referred to as n. 1 and in a continued line represents the starting position of working or initial casting therefore the starting position of haulage of the end plug 2 of the continuous casting billet 17.
In this embodiment the arm 1 results attached in a fixed _" position on a driving shaft 18 operated by a screwed reduction gear without end 3 the which in its turn receives its movement from an epicycloidal reducer 4 which is primarily operated by a direct current motor or hydraulic motor 5 at variable speed. The free rotational end of the arm 1 presents in this embodiment by a support bracket 6, an interchangeable haulage arm 7 the which is complete with a hooking eyelet 8 to hook itself to a hooking-up system 9 provided behind the end plug 2. The apparatus obviously results installed and works under context of the casting plan 10 where in the specific case the curve casting box 11 is supported (but it could even be straight). In the case for example of a straight casting box (not illustrated) the haulage support 7 on the end of the arm 1 could even be jointed for example with the application of a further intermediate articulation (not illustrated in the figure).
In the illustration of figure 1 schematically represented is the position of the oscillation device of the casting box 12 and of the billet supporting rollers 13; the continuous casting chamber presents also a closing wall chamber 14 whilst before the closing wall is provided a pair of rollers of a straightening action 15 and on the exit from the chamber is provided a draught and straightening unit by haulage rollers 16', 16".
From figure 1 can also be noted that the haulage arm 1 unhooks itself from the end plug 2' after the second couple of haulage rollers 16',_'16" represented by a dotted line with the n. 1' for the arm and 2'rfor the end plug.
As is noted in figure 2 the casting pathways can be several, placed side-by-side, and obviously the haulage arms 1 can be several, one for each pathway, destined to haul each billet in continuous casting 17.
In the specific case of figure 2 the haulage arm 1 results substantially oriented in a vertical position above the height of the first pair of haulage rollers 16' of draught and straightening unit and that is to understand the structure and working of the device.
Obviously in the case shown in figures 1 and 2, with one haulage arm 1 and a fixed rotational centre 18 will be had an extraction pathway of the billet for feeding of the continuous casting in a semi-circle path with a radius R and the haulage of the arm 1 will be made for a part of a circle of about 90 rather more than less.
Naturally the pathway of continuous casting could be even different from the semi-circle for example using the variable solutions proposed, however these are more complicated for the specific uses in which the arm 7 is jointed and driven on a rotational centre 18 in its turn movable and not fixed in a way that the movements of the jointed rotational centres 18 with the rotation of the arm 1 determine the pathway needed for that continuous casting special plant.

Claims

1. Draft gear of the billet-in continuous casting plants, comprising a haulage arm (1) of the billet (17) rotating, around a rotational centre (18) for a determined angle of rotation, by predeterminable variable control drive means (2,4,5), and wherein the free end (7) of the said haulage arm (1) presents a hooking-up means (8) to hook itself to the end plug (2) of continuous casting billet (17) starting to haul the said plug (2) from a starting position of casting in the casting box (11) to a position of automatic downstream unhooking (1',2') after having hauled the billet (17) in a continual formation in the casting box (11) along the pre-established extraction pathway downstream the haulage rollers (16', 16").

2. A device as claimed in claim 1, in which the said rotational centre (18) for the angular rotation of the said haulage arm (1) is fixed and the arm (1) effects an angular oscillation equal to about 90° the which corrispond to the pathway run by the end (7) of the arm (1) from the hooking-up vertical position to the end plug (2) of the billet (17) at the casting box (11) to an un-hooking horizontal position.

3. A device as claimed in claim 1, in which the end (7) of the arm (1) is articulated on the second one.

4. A device as claimed in claim 1, in which the rotational centre (18) of the haulage arm (1) is movable by driving means, in accordance and/or independently from the rotational movement of the arm (1).

5. A device as claimed in claim 1, in which the said haulage arm (1) is hinged onto another upstream driving arm.

6. A continuous casting plant comprising at least one device as claimed in any of preceding claims comprising a plurality of continuous casting pathways, in which each of these is provided with a haulage arm (1) for hauling a respective casting billet (17)..