ROLL FOR ROLLING METAL PRODUCTS

Abstract: A roll for rolling metal products has at least one roll neck (2). In order to provide for recognition of the roll, during its circulation in a plant for regrinding, an identification code for the roll, which is readable by a reading apparatus, is provided on the end surface of the neck (2), the code being formed by removal of material from the neck at a predetermined location or locations so as to define, together with un-removed material, elements (3) of the code. A binary code formed by concentric grooves (3) is used.

Description: The invention relates to a roll for rolling metal products, and to a method for identifying such a roll. Rollers for rolling products are widely used for example in the steel and aluminium industries, and are employed in roll stands for the purpose of reducing the thickness of, for example, metal strips or slabs. In some cases a combination of work rolls and back-up rolls with the work rolls coming into direct contact with the material being rolled and being supported by the back-up rolls is used. Because of this contact of work rolls with the metal strip or slab, which is generally at a temperature of several hundreds of degrees Centigrade or more, considerable wear on the work rolls results. So as to limit to the greatest possible extent the pressure of the associated wear-profile on the surface of the strip or slab being rolled, the work rolls are reground after a certain time interval. This does not, however, prevent the work rolls and the back-up rolls also from becoming worn. These back-up rolls should therefore be reground also after a certain interval. In certain circumstances it can become necessary in a hot-strip rolling-mill to remove both back-up rolls and work rolls at the same time for regrinding. This can happen when a jam occurs. The finishing train which is a set of roll stands is particularly liable to this. Besides, after each rolling programme e.g. after about one hour, roll changing takes place. From each roll stand the work rolls are removed and taken away for grinding to be made ready once again for use in a new rolling programme. However, grinding the rolls consumes further time. Their removal, cooling and dismantling can occupy as much as three hours. For this reason, in any rolling mill, there must be a significant number of rolls in circulation. The situation is made worse by the fact that it is desirable to handle the rolls individually during grinding. This is because different rolling profiles are required; for example, sometimes rolls with a relatively concave profile are needed, while others need a relatively convex profile. This individual handling of rolls is very much a desideratum if control of the rolls is to be efficient and the rolls themselves are to have long working lives. There is therefore a problem of recognizing or identifying individual rolls. The present invention is addressed to the solution of this problem. According to the invention, an identification code for the roll, which code is readable by a reading apparatus, is provided on a surface of the neck, the code being formed by removal of material from the neck at a predetermined location or locations so as to define, together with un-removed material, elements of the code. The code may consist of figures or letters, or a combination of figures and letters, but preferably the code is binary. The advantage of this is that the reading apparatus used need not be so complex as in the case when figures/letters are used. The code can be located in that part of the neck which runs concentrically with the roll axis, or on the axial end-face of the neck. Preferably the code is located on the axial end-face of the neck, which has the advantage that this position is the most easily accessible. Preferably grooves are made at the places where material has been removed to form the code. This has the advantage that it is possible to read the code from a plurality of different places, thus reducing the legibility difficulty caused by the presence of dirt. By making the grooves rectangular in cross section the reading apparatus is better able to distinguish where material has been removed. The grooves should preferably be annular and located concentrically with the roll axis so that the operation of the reading apparatus is independent of its position with respect to the axis of the roll. If the code is to be read easily, these grooves must be placed in an identifiable position on the end-face of the roll neck. To this end, the grooves may have the same diameters on all rolls. It is better still to fix end markers on each side of the code in the reading direction, so that the reading apparatus can be manoeuvred quickly into the right position. The advantage of this is that the reading system is not required accurately to determine the middle point of the code (i.e. roll axis) to enable the code to be read. The invention also relates to a method for identifying a roll for rolling metal products which roll is as defined above according to the invention. Suitably, in the method, a reading apparatus for said code is used which apparatus executes at least one reading cycle and has a plurality of tuned resonance circuits which are selectively disturbed in dependence on the presence or absence of material constituting the code elements, so that the sequence of disturbed and undisturbed circuits corresponds to the code. In this way no physical contact between roll and reading apparatus is required; thus the reading apparatus stays clean and is not vulnerable to the principal contaminants, such as oil and grease, of the working environment where the roll is used. In order to achieve a reduced sensitivity to disturbances where the reading apparatus is highly sensitive, preferably the reading cycle is repeated, after re-alignment of the reading apparatus relative to the roll neck, the steps of realignment and reading being repeated until the code has been read identically a plurality of times. An embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawing, in which:- Figure 1 is a perspective view of part of a roll embodying the invention; Figure 2 is a detail of one neck of the roll of Fig. 1 in cross section through the rotational axis of the roll. On both ends of the roll 1 of Fig. 1 there is a neck 2. In one of the necks 2 a code is located in the axial end face 6, this code being formed by annular grooves 3, concentric with the axis of the roll 1. Fig. 2 shows that these grooves 3 are rectangular in cross section. Figs. 1 and 2 also show the central hole 7 of the roll, which is not relevant to the present invention. The grooves 3, together with the material positioned on the surface of the end face 6 between code and markers 4 and 5, constitute the binary code by which the roll 1 is identified. The number of grooves shown is for example only. In encoding, of course the presence or absence of a groove can provide an element of the binary code. The binary code whose elements are annular on the end face 6, can be approached in a straightforward manner by a reading apparatus (not shown) and then read. For this purpose the end markers 4 and 5 serve to define the beginning and end of the code, and for positioning the reading apparatus. Using the effect which the material of which the neck is made has on the magnetic fields, the reading apparatus includes a number of tuned resonance-circuits. There should be as many of these resonance-circuits as there are binary bits in the code, plus two extra circuits for detecting the marker surfaces 4 and 5. As a result of the absence of material next to where the resonance circuit is, e.g. when the circuit is close to a groove 3, the behaviour of the circuit alters. The altered behaviour in this way corresponds to the presence of a groove 3 located in the end face 6. The presence of absence of a groove thus forms part of the code. Any dirt present in and around the grooves 3 or on the markers 4 and 5 can, however, adversely affect the performance of the reading system. To circumvent this the reading cycle described is repeated several times at different alignments of the reading apparatus relative to the roll until a series of identical values of the code are obtained in succession.

Claims: 1. A roll for rolling metal products, having at least one roll neck (2) characterized in that an identification code for the roll, which code is readable by a reading apparatus, is provided on a surface of the neck (2), the code being formed by removal of material from the neck at a predetermined location or locations so as to define, together with un-removed material, elements (3) of the code. 2. A roll according to claim 1 wherein the code is a binary code. 3. A roll according to claim 1 or claim 2 wherein the code is provided on an axial end-face (6) of the neck (2). 4. A roll according to any one of claims 1 to 3 wherein said removal of material has formed grooves (3). 5. A roll according to claim 4 wherein said grooves (3) are rectangular in cross-section. 6. A roll according to claim 4 or claim 5 wherein said grooves are annular and concentric with the roll-axis. 7. A roll according to any one of the preceding claims wherein the code includes end-marking elements to define the ends of the code when being read. 8. A method of identifying a roll for rolling metal products characterized in that the roll is a roll as claimed in any one of claims 1 to 7 and in that a reading apparatus for said code is used which apparatus executes at least one reading cycle and has a plurality of tuned resonance circuits which are selectively disturbed in dependence on the presence or absence of material constituting the code elements, so that the sequence of disturbed and undisturbed circuits corresponds to the code. 9. A method according to claim 8 wherein the reading cycle is repeated, after re-alignment of the reading apparatus relative to the roll neck, the steps of realignment and reading being repeated until the code has been read identically a plurality of times.

Inventors: KOOMEN, PIETER, VOS, BARTHOLD ULFERT
Applicants: HOOGOVENS GROEP B.V.
Application year: 1986
Main classification: B21B27
IPC codes: B21B27, B07C5, B21C51