LU85266A1 - IMPROVEMENTS IN METHODS FOR IMPROVING THE SURFACE CONDITION OF A CYLINDER - Google Patents

Description

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C 2294/8403.

METALLURGICAL RESEARCH CENTER -CENTRUM V00R RESEARCH IN DE METALLURGIE,

Non-profit association -Vereniging zonder winstoogmerk in BRUXELLES, (Belgium).

Improvements to processes for improving the surface condition of a cylinder.

The present invention relates to improvements in methods for improving the surface condition of a cylinder, using a focused corpuscular beam, such as a laser beam.

This process applies in particular to rolling mill rolls ü or to rolls used in continuous annealing installations! continuous with steel strips.

i; i! In this field, several methods and devices are already known: I: 1 devices, proposed in particular by the present applicant, making it possible to create a controlled roughness on the surface of the cylinders. In this regard, reference may in particular be made to Belgian patent N ° I 880.996.

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Tl s | The known methods have an important drawback linked to the fact that the current transmitting devices are fixed, in particular because of their weight and their volume. They are generally arranged so emitting a beam in a direction parallel to the longitudinal axis of the cylinder; this beam is returned to the surface of this cylinder by a marking head which contains at least one deflection mirror and a system; * · for focusing the beam on the surface of the cylinder. This head moves parallel to the axis of the cylinder, so that the distance between the marking head and the emitting device varies during operation. As a result, in particular, a defect in the parallelism of the emitted beam can cause a displacement! surround the plane of focus of the reflected beam and consequently a heterogeneity in the roughness imprinted on the surface of the cylinder.

However, there have recently appeared lighter emitters, in particular laser emitters, of sufficient power, which make it possible, in particular by virtue of the process which is the subject of the present invention, to remedy the aforementioned drawbacks.

To this end, the method of the invention is essentially characterized in that there is a corpuscular beam emitter such that it emits a beam in a direction substantially perpendicular to the axis of the cylinder, in that the 'said beam is focused on the surface of the cylinder; and in that the said transmitter is moved parallel to the cylinder axis.

f! '' According to an interesting variant, the cylinder is rotated with a speed which is preferably synchronized with; £.

the speed of movement of the transmitter.

I The use of a mobile transmitter in accordance with the invention offers various advantages over known methods based on the use of a fixed transmitter.

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First, the transmitter can be placed a short distance from the surface to be treated; consequently, a possible lack of parallelism of the beam will have practically no influence on the position of the plane of focus of the beam and „consequently on the homogeneity of the roughness created on the face of the cylinder.

It should moreover be emphasized that the method of the invention would make it possible to easily remove a possible influence from such a defect in parallelism of the beam. Indeed, the emitter moves parallel to the axis of the cylinder and the length of the beam from the emitter to the surface of the cylinder is therefore constant. Under these conditions, the initial focusing focus does not normally require any further adjustment.

Finally, the method of the invention makes it possible to simplify the "optical system required, by eliminating in particular the beam reflection devices.

Of course, it would not be outside the scope of the invention to combine the use of a mobile transmitter with other operations known per se, such as modulation or intermittent interruption, or chopping, of the beam.

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Claims (3)

1. Method for improving the surface condition of a cylinder, in which a controlled roughness is created on the surface of the cylinder, by means of a corpuscular beam, characterized in that 1 * a corpuscular beam emitter is available such that it emits a beam in a direction substantially perpendicular to the axis of the cylinder, in that the said beam is focused on the surface of the cylinder and in that the said emitter is moved parallel to the cylinder axis. 2. Method according to claim 1, characterized in that the said cylinder is rotated about its longitudinal axis, with a speed which is preferably synchronized with the speed of movement of said transmitter. ........ 3 .. description pages ..... 4. pages this claim Ή 0! - ', r; Ρ'ίϊί'Γ'ίΐρ ^ | ViS is-sx ti ι ^ Ι-. · »Ϋ · α y. Iv - ·! jf j-; 'f i J ï * j \ j i \ | • i