GB2223432A

GB2223432A - Machining blooms and billets

Info

Publication number: GB2223432A
Application number: GB8919185A
Authority: GB
Inventors: Oskar Noe; Rolf Noe; Andreas Noe; Hermann Koppers; Heinz Schmitter; Herbert Lux; Herbert Beuther
Original assignee: BWG Bergwerk und Walzwerk Maschinenbau GmbH
Current assignee: BWG Bergwerk und Walzwerk Maschinenbau GmbH
Priority date: 1988-10-08
Filing date: 1989-08-23
Publication date: 1990-04-11
Also published as: FR2637525A1; DE3834279A1; GB8919185D0

Description

-7 2 24 3, 2 PROCESS AND EQUIPMENT FOR MACHINING BLOOMS AND BILLETS This

invention relates to a process for the chipremoving machining of blooms and billets,, more particularly for the edge and face grinding of longitudinally and/or transversely cut blooms.

The majority of blooms and billets are nowadays produced in continuous casting machines. on economic grounds,, the moulds are not varied in conformity with the bloom dimensions required for any specific purpose; broad blooms are cast and later flame cut transversely and longitudinally to the required bloom breadths and lengths. However, flame cut surfaces are flawed by undesirable side effectst which produce for example slag and metal residues known as burns - irregular cut facesy warping and#, in the case of carbon steels, local decarburisation. With the exception of warping, all these flaws can be rectified by edge and face grinding. It might seem that cut blooms could be machined with the aid of manually operated or manually controlled grinding tools. Howeveri, this is extremely time-consuming and costly.

Burns are removed with the aid of burn breakers,, as they are called. Flame scarfing is a known aiternativer but such methods do not reliably remove slag or embedded metal residues on the edges and cut faces of transversely and/or longitudinally cut blooms, and decarburisation once again occurs in carbon steels.

The object of the invention is to provide a process and equipment whereby the chip-removing machining of blooms --- -0 and billets, more particularly the edge and face grinding of longitudinally and/or transversely cut bloomsg, can be automated in a rational and cost-reducing manner, devoid of any safety hazards.

According to one aspect of the present invention, a process for the chipremoving machining of blooms and billets comprises measuring the contours of each succeeding bloom in the X-, Y- and Z-directionsy together with its coordinates on a feed trolleyr the feed speed of the bloom and/or the feed trolleyr and the distance remaining before the machining position is reached are determined, the tools being positioned and their feed movements during the bloom machining cycle being adjusted in conformity with the data, and the bloom being fed continuously through the machining station. In the context of the invention, the feed trolley can be replaced by some other mobile feederr such as a feed slide for example.

The incoming bloom is measured precisely in the X-, Yand Z-coordinates. The data are memorised and used to adjust the tools in conjunction with the measured speed and coordinates of the feed trolley. When the bloom encounters the tools it is alreay advancing into the required machining position, so that the feed trolley can advance through the machining station at the prescribed speed, without interruption. Troughs and ridges on the cut faces, resulting f rom fluctuations in the cutting gas pressure" or other variables#, are tracked together with any warpage, i. e., possible longitudinal curvature in the horizontal and/or vertical directions.The tools are adjusted in conformity n / 1 with the measured data and can accordingly follow any curve, trough or ridge. Cut blooms may only have one cut face,, but if the strand is cut into three blooms, the middle one will, hav e tw o cut f ace s, one on e ach f I ank. In the case of plain steels, the longitudinally and/or transversely cut blooms are usually only machined on and near the edges, to remove local slag and metal residues, since otherwise on cold rolling the blooms into sheet form any minor flaws would be stretched under the rolls to a length of several meters, rendering the product unusable. In the case of carbon steels,, the entire cut faces are. usually machined to remove the decarburised zone, which extends several tenths of a millimeter under the cut faces.

Further and preferred features of the invention will now be described. Thus, the tool pressure may be regulated to conf orm to the quality of the bloom material, and be monitored by a force measuring device, for example a dynamometer capsule. As a resulty a constant stock removal rate can be maintained. In cases - such as carbon steels when the entire cut f aces are machined, the bloom is preferably reciprocated several times through the machining station and then optionally rotated and brought into the next machining position, for example for edge grinding.

According to another aspect of the invention, equipment f or carrying out the process and employing outstandingly simple yet functionally reliable means, comprises a grinding station and a feed trolley, the grinding station being preceded by a meauring station through which the - 5 feed trolley must passr and in which measurements are made of the incoming bloom contours in the X-,, Y- amd Z-directions and also of the feed speed of the bloom and/or the feed trolley, the grinding station being provided with a tool inthe form of a grinding wheel adjustable in the X- and Y-directions, a f orce measuring device and a grinding pressure control circuit, the feed trolley being fed through the grinding station in the Z-direction,, and the measurement data being transmitted to a central electronic unit, which is connected to the measuring station and the grinding station and which comprises at least a data store, a micro-processor and a controller.

Successive blooms are regularly machined by the edge or face grinding method. Since the distance betwen the measuring station and the machining or grinding station is known, there is no need for path measurements to determine the bloom feed speed. In any case the positional data on the bloom, determined with the aid of lasers, impulse senders or other measuring devicesf and corresponding to the distance from the measuring station to the grinding station are transmitted through slide registers from the central unit etc. to its data store in such a manner that the correct grinding wheel control data are provided for the positional adjustments and feed motions of the grinding wheel. This applies to both directions of feed trolley and bloom movement and/or grinding. in every case, all the actions required for the programmestored control of the equipment are processed into a grinding programme conforming to the measurement data on each successive bloom,, the material and dimensional data on the bloom being assimilated by the central electronic unit. The grinding wheel can be mounted on a tool slide free to move in the X- and Y-directions, whilst the feed trolley has a bloom clamping and turning mechanism and can travel on exactly located guide rails. The bloom clamping mechanism simultaneously ensures that the incoming bloom is correctly aligned on the feed trolley. The bloom turning mechanism allows the turning of the bloom on the trolley repeatedly through 900 to expose the various cut faces to the wheel. Since the measurements on each successive bloom must be made with extreme precision,, to avoid damage to the toolp for example disintegration of the grinding wheel because of inaccurate positioning, the measuring station should preferably be equipped with laser heads, whereby the exact vertical, transverse and longitudinal measurements including warpage if encountered, can be determined and put in store.

Consequently,, the invention provides a process and equipment for 'the chip-forming machining of blooms and billetst whereby the edge and face grinding of longitudinally and/or transversely cut blooms in particular can be carried out in a rational and fully automatic manner, at minimum labour costs and with freedom from safety hazards.

An embodiment of the invention will now be described, purely by way of example, with reference to the accompanying drawings in which:- Figure 1 is a diagrammatic side elevation of bloom grinding equipment in accordance witih the invention; Figure 2 is a plan view of the equipment of Figure 1; Figure 3 is a diagrammatic cross section showing the positioning of the grinding wheel for the edge grinding of a bloom lying flat; Figure 4 corresponds to Figure 3 but shows the positioning of the grinding wheel for the face grinding of a bloom lying flat; Figure 5 isa perspectiveview showingpartof abloom after deburring and burn removal on the top and bottom faces; Figure 6 corresponds to Figure 5 but shows part of a bloom with entire grinding on cut faces and burn removal on the top and bottom faces; Figure 7 also corresponds to Figure 5 but shows part of a bloom with entire cutting on all faces and preliminary burn removal on the top and bottom faces; and Figure 8 likewise corresponds to Figure 5 but shows part of a bloom with edge grinding and burn removal on the top and bottom faces.

Figures I and 2 depict equipment f or the edge and f ace grinding of longitudinally and/or transversely cut blooms 1 or billets to ef f ect chip-removing machining -thereof. The equipment has a grinding station 2 and a feed trolley 3, the grinding station 2 being preceded by a measuring station 4 through which the feed trolley 3 must passr and in which measurements are made of the incoming bloom contours in the XY- and Z-directions and also of the feed speed of the bloom and/or the feed trolley. The grinding station 2 has a grinding wheel 5 (see also Figures 3 and 4) adjustable in the 1 X- and Y-directions, and a f orce measuring device and a grinding pressure control circuit, the latter items not being sh ow n. The feed trolley 3 is fed through the grinding station 2 in the Z-direction. The data measured at the measuring station 4 are transmitted to a central electronic unit 6 which is connected to the measuring station 4 and the grinding station 2 and which comprises at least a data stores, a micro- processor and a controller. The grinding wheel 5 is mounted on a toolslide 7 free to move in the X- and Ydirections. The feed trolley 3 has a bloom clamping and turning mechanism 8 and can travel on exactly located guide rails 9. In f act,, the f eed trolley 3 has special longitudinal motion guides, which function extremely preciselyr so that the grinding wheel 5 can be adjusted equally precisely. The measuring station is equipped with laser heads 10t which ensure an equally precise measuring of the incoming bloom 1.

Claims

A process for the chip-removing machining of blooms and billets comprising measuring the contours of each succeeding bloom in the X-, Y- and Z-directionso, together with its coordinates on a feed trolley,, the feed speed of the bloom and/or the feed trolleyo, and the distance remaining before the machining position is reached are determined, the tools being positioned and their feed movements during the bloom machining cycle being adjusted in conformity with the data, and the bloom being fed continuously through the machining station.
2. A process as in Claim lF wherein the tool pressure is regulated to conform to the quality of the bloom material,, and is monitored by a force measuring device, for example a dynamometer capsule.
3. A process as in Claim 1 or Claim 2, wherein the bloom is reciprocated several times through the machining station and then optionally rotated.
4. Equipment for carrying out the process as in any one of Claims l.to 3, comprising a grinding station and a feed trolley, the grinding station being preceded by a measuring station through which the feed trolley must pass, and in which measurements are made of the incoming.bloom contours in the X-j, Y- and Z-directions and also of the bloom feed speed and/or of the feed trolleyr the grinding station being provided with a grinding wheel adjustable in the X- and Ydirections, a force measuring device and a grinding pressure control circuit, the feed trolley being fed through the grinding station in the Z-direction,, and the measurement data Z 1 being transmitted to a central electronic unit which is connected to the measuring station and the grinding station and which comprises at least a data store# a micro-processor and a controller.
5. Equipment as in Claim 49, wherein the grinding wheel is mounted on a toolslide free to move in the X- and Ydirections.
6. Equipment as in Claim 4 or Claim 5p wherein the feed trolley has a bloom clamping and turning mechanism and can travel on exactly located guide rails.
7. Equipment as in any one of Claims 4 to 6r wherein the measuring station is equipped with laser heads.
8. A process f or the chip-removing machining of blooms and billets substantially as hereinbef ore described with reference to the accompanying drawings.
9. Equipment for carrying out the process of Claim 8 and substantially as hereinbefore described with reference to the accompanying drawings.

PubhshedI99O at The Patent Office. State House, 66 71 High Holborn, London WCIR4TP. Further copies maybe obtained from The Patent Office Sales Branch. St Mary Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd. St Mary Cray. Kent. Con 187