Apparatus and process for the surface treatment of cylinder bodies, in particular laminated cylinders - Patents.com

Abstract

An apparatus (10) and method for the surface treatment of a cylinder body (1), in particular for the surface repair of laminated cylinders. The apparatus comprises a workstation (100) configured to receive a cylinder body having a side surface movable by rotation about a rotation axis K, a laser emitter (600) configured to cooperate with the workstation and to emit at least one laser beam, a contour detector (700) configured to detect a detected surface contour of the side surface of the cylinder body, and a control unit (15) configured to operatively execute at least one procedure for repairing the side surface of the cylinder body. The repair procedure comprises a procedure for detecting the surface contour of the cylinder body, comprising a step of comparing the detected surface contour with a target surface contour, and a removal procedure, comprising a step of irradiating the cylinder body with a laser beam to remove metallic material and obtain the target surface contour.

Description

[Technical field]

[0001] The present invention relates to an apparatus and a method for treating the side or shell surfaces of cylinder bodies, such as, for example, laminated cylinders in rolling mills, with a laser emitter. In particular, the invention finds preferential application for the grinding of rolling cylinders with a laser emitter. The laminated cylinders are intended for use in rolling mills for hot or cold rolling flat metal products, in particular strips of steel, aluminum, other metals or polymer materials, or in paper mills. [Background technology]

[0002] Rolling of strips of steel, aluminum, other metal or polymer sheet material, or paper, is accomplished using laminating (or "rolling") cylinders in a rolling mill. Such strips are forced to pass between opposing rolling cylinders, exerting high pressure on the strip. The laminating cylinders may have a pattern or texturing configured to be replicated on the side or mantle of the laminated web during the rolling stage, also referred to in technical terms as the "table" of the laminating cylinder. The pattern or texturing of the laminating cylinder table may include a predetermined surface roughness that is replicated on the web being laminated.

[0003] Texturing processes are known which are carried out by electrical discharge (EDT) or laser emitters acting on the side of a rolling cylinder. The surface roughness produced by a laser can be a function of the intensity of the laser beam and the distance interposed between the laser emitter and the side of the rolling cylinder.

[0004] During rolling, the rolls are subject to progressive deterioration that depends on pressure, wear, temperature, the type of process and the material being processed. For example, the sides or tables of the rolling cylinders may retain contaminants including traces of lubricant, flakes or metallic residues, which can adversely affect the processing quality of the rolled strip.

[0005] Furthermore, as the rolling cycle progresses, the sides of the rolling cylinders may wear. For example, the cylinders may gradually lose the surface roughness characteristics necessary to produce the required roughness in the metal strip. The surface roughness of the rolling cylinders may vary, for example, in values ​​of characteristic parameters such as Ra and Rpc, beyond predefined limits, for example 20 percent of the nominal value.

[0006] Cracks, dents and localized damage of various types, shapes and depths can also occur on the sides of the lamination cylinders, adversely affecting the final result of the laminate web.

[0007] Finally, the surface layers of the sides or table surfaces of the rolling cylinders are subjected to high stresses which can lead to fatigue phenomena and impair the desired surface properties.

[0008] Following deterioration of the rolling cylinder, it may be necessary to temporarily remove the cylinder from the rolling mill to restore the original surface characteristics.

[0009] To date, such restoration is carried out by machining, for example by grinding the cylinder using an abrasive wheel process. Grinding is the only technological process that can be used at present to achieve the desired result, mainly due to the hardness of the material from which the cylinder is made and the roughness values ​​obtained. Cylinder grinding involves the removal of a predetermined thickness of material from the side of the cylinder or table in order to restore the appropriate roughness, eliminating surface defects such as cracks and dents, and restoring the cylinder's contour to the required tolerances (shape, roughness, eccentricity of the generating element or contour) by means of a rolling mill.

[0010] This grinding technique can effectively and efficiently achieve roughness (Ra) in the range of 0.02 μm to 2.5 μm. Within that range, the grinding process requires a predefined number of passes in combination with machining steps commonly identified as roughing, semi-finishing and finishing, with machining parameters being changed between these steps and the grinding wheel being changed as necessary to achieve the desired final roughness.

[0011] Conventional grinding machines require relatively high power, typically on the order of tens or hundreds of kW, to rotate the rolling cylinder and overcome the friction generated by forcing the grinding wheel into contact with the side of the cylinder.

[0012] Mechanical grinding operations using abrasive wheels involve high temperatures on the surface of the cylinder and on the cutting tool (actually the grinding wheel), necessitating the use of a cooling fluid to keep local temperatures within acceptable limits. The waste products from such grinding processes include chips of the constituent metal of the rolling cylinders, diamond grit, binder resin particles and emulsified coolant, defining a waste wet sludge which must be properly disposed of.

[0013] The high power required, the high heat energy generated by the grinding wheel / surface friction, and the presence of waste moisture sludge result in high costs of the refurbishment process of rolled / laminated cylinders, or of cylinder bodies in general. Summary of the Invention [Problem to be solved by the invention]

[0014] Object of the Invention SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to overcome at least one of the deficiencies and / or limitations of conventional approaches.

[0015] A first object is to provide a method and apparatus for grinding the side or mantle surface of a cylinder body which is more energy efficient.

[0016] A further object is to provide a method and apparatus for grinding the side or mantle surface of a cylinder body which can effectively restore the original side and tolerances in a reasonable amount of time.

[0017] A further object is to provide a method and apparatus for grinding the sides or mantle surfaces of a cylinder body whereby waste material is easily removed from the processing area.

[0018] A further object is to provide a method and apparatus for grinding the side or mantle surface of a cylinder body that can reduce waste disposal costs.

[0019] A further object is to provide a method and apparatus for grinding the side or mantle surface of a cylinder body that can reduce the cost of the grinding process.

[0020] A further object is to provide a method and apparatus for grinding the side or shell surface of a cylinder body which allows optimizing the amount of material removed during the grinding process.

[0021] These and other objects, which will become more apparent from the following description and embodiments, are substantially achieved by methods and apparatus according to one or more of the following claims and / or embodiments. [Means for solving the problem]

[0022] (Summary) The first aspect relates to an apparatus (10) for the surface treatment of cylinder bodies (1), in particular for the surface restoration of laminated cylinders. The apparatus comprises: a workstation (100) defining at least one operating position configured to receive, in an operating state (10) of the device, a cylinder body (1) having a side surface (4), the workstation (100) being configured to support the cylinder body (1) in rotation according to a predetermined axis of rotation (K); at least one laser emitter (600, 600") configured to cooperate with the workstation (100) and to emit at least one laser beam in the direction of said working location, the at least one laser emitter (600, 600") being movable at least along a main axis (Z) substantially parallel to the rotation axis (K) of the cylinder body (1); at least one contour detector (700) movable at least along a detection axis (Y) substantially parallel to the rotation axis (K) of the cylinder body (1), and configured to detect a detection surface contour of a side surface (4) of the cylinder body (1) under a use state of the device; a control unit (15) operatively connected to the laser emitter (600, 600") and to said at least one contour detector (700), the control unit (15) being configured to perform a repair procedure on at least one side surface (4) of the cylinder body (1) during said device use state, The repair procedure includes a detection procedure and a removal procedure; The detection procedure includes at least the steps of detecting a detected surface profile (DSP) of the cylinder body (1) using the profile detector (700) and comparing the detected surface profile (DSP) with a target surface profile (TSP) of the cylinder body (1); The removal procedure is performed according to the comparison and includes at least a step of emitting a laser beam through a laser emitter (600, 600") towards a side surface (4) of the cylinder body (1) to obtain the target surface contour (TSP), the laser beam being configured to locally remove metal material from the cylinder body (1).

[0023] A second aspect relates to a method for grinding a rolled / laminate cylinder, optionally using a device according to the previous aspect, said cylinder body (1) having a side surface (4) extending longitudinally along a rotation axis (K) between a first end and a second end of the cylinder body (1), The method includes at least one repair procedure (2000) of a side surface (4) of a cylinder body (1), the repair procedure comprising: o A detection procedure (2001) that includes at least the following steps: 3) A step of detecting the surface contour (DSP) of the side surface (4) of the cylinder body (1) using a contour detector (700). 3. Step (1) of comparing the detected surface contour with a target surface contour (TSP) of the cylinder body (1). o a removal procedure (2002) carried out according to said comparison, comprising the steps of: (ii) A step of emitting a laser beam through a laser emitter (600, 600") toward the side surface (4) of the cylinder body (1) to obtain the target surface contour (TSP). The laser beam locally removes metal material from the cylinder body (1).

[0024] In a further aspect according to any of the previous aspects, the rolling cylinder is for carrying out a rolling operation of a metallic material or for the production of a paper sheet.

[0025] A third aspect relates to a method for surface treatment of a cylinder body (1), optionally using a device according to the first aspect, in particular for surface restoration of laminated cylinders, The cylinder body (1) is movable by rotation about a rotation axis (K) and includes a side surface (4) extending longitudinally between a first end and a second end of the cylinder body (1); The method includes a repair procedure of at least one side surface (4) of the cylinder body (1), the repair procedure comprising: A detection procedure comprising at least the steps of: 3) A step of detecting the surface contour of the side surface (4) of the cylinder body (1) using a contour detector (700). 3. Step (1) of comparing the detected surface contour with a target surface contour (TSP) of the cylinder body (1). a removal procedure, performed according to said comparison, comprising the steps of: (ii) A step of emitting a laser beam through a laser emitter (600, 600") toward a side surface (4) of the cylinder body (1) to obtain the target surface contour (TSP), the laser beam locally removing metal material from the cylinder body (1).

[0026] In a fourth aspect according to any of the above aspects, the surface contour and the target surface contour (TSP) of the cylinder body (1) are the angular position of the cylinder body (1), and Linear position along the detection axis (Y), at least one variable geometric characteristic that varies according to at least one of The at least one geometric characteristic of the detected surface contour (DSP) comprises at least one individual altitude parameter representative of the diameter of the cylinder body (1) and / or the variation of said diameter of the cylinder body (1) and / or the intervening distance between the side surface (4) of the cylinder body (1) and the contour detector (700).

[0027] In a fifth aspect related to the previous aspect, the at least one target surface contour geometric characteristic (TSP) comprises at least one individual target altitude parameter representative of the diameter of the cylinder body (1) and / or the variation of said diameter of the cylinder body (1) and / or the intervening distance between a side surface (4) of the cylinder body (1) and the contour detector (700) during operating conditions and subsequent removal procedures.

[0028] In a sixth aspect according to any of the previous aspects, the control unit is configured to operate as follows. Moving the contour detector (700) along the detection axis (Y). Detecting said surface contour (DSP) by a contour detector (700) while moving the contour detector (700) along a detection axis (Y). · Associating said at least one geometric feature of the detected surface contour (DSP) of the cylinder body (1) with a respective linear position along the detection axis (Y). And, if necessary, Rotationally moving the cylinder body (1) about a rotation axis (K), in particular by means of an electric motor operatively connected to the cylinder body. Detecting the surface contour (DSP) using a contour detector (700) during rotation of the cylinder body. · Associating said at least one geometric feature of the detected surface contour (DSP) of the cylinder body (1) with a respective angular position of the cylinder body (1).

[0029] In a seventh aspect according to any of the previous aspects, the control unit (15) is configured to emit a pulsed laser beam during the removal procedure, in particular the pulses being a duration between 100 fs (femtoseconds) and 1000 ns (nanoseconds), or between 1 fs and 1000 μs (microseconds), or between 1 ns and 1000 ns, or between 1 fs and 1000 ps (picoseconds), and / or Peak power between 1kW and 10MW, specifically between 10kW and 2MW, has.

[0030] In an eighth aspect according to any of the previous aspects, the pulsed laser beam is configured to remove material from the cylinder body (1), the removal step producing a powder of the removed material, the material being a metal, in particular steel.

[0031] In a ninth aspect relating to any of the previous aspects, a differential contour parameter of the cylinder body (1) is defined by comparing the detected surface contour (DSP) with the target surface contour (TSP), the differential contour parameter representing the difference or ratio between the detected surface contour (DSP) and the target surface contour (TSP).

[0032] In a tenth aspect according to any of the previous aspects, the control unit is configured to adjust at least one operating parameter of the apparatus according to said difference contour parameter during the removal procedure.

[0033] In an eleventh aspect according to the previous aspect, the at least one operating parameter of the device comprises at least one control parameter of a laser beam emitted by the laser emitter (600, 600"), said control parameter comprising at least one of an average power of the laser beam, a peak power of the laser beam, a duration of a laser beam pulse, a duration of an interval between laser beam pulses, a size of the laser beam, a distance between the laser emitter (600, 600") and an outer surface of the cylinder body (1), a radiation frequency of the laser beam pulse.

[0034] In a twelfth aspect according to the previous two aspects, the control unit is configured to adjust control parameters of the laser beam emitted by the laser emitter (600, 600") (including peak power of the laser beam, pulse duration of the laser beam, and optionally average power of the laser beam) in response to the differential parameter.

[0035] In a thirteenth aspect according to any of the tenth to previous aspects, the operating parameters include a laser emitter displacement speed (600, 600") along a main (Z) direction during emission of the laser beam towards an outer surface of the cylinder body (1).

[0036] In a fourteenth aspect relating to any of the tenth to previous aspects, the operating parameters include an angular velocity of the cylindrical body (1) about its rotation axis (K) during emission of the laser beam toward an outer surface of the cylindrical body (1).

[0037] In a fifteenth aspect according to any of the tenth to previous aspects, the operating parameters include a number of passes that the laser beam makes incident on the same portion of the side surface (4) of the cylindrical body (1).

[0038] In a sixteenth aspect according to any of the tenth to previous aspects, the operating parameters include an exposure time during which the laser beam is incident on the same portion of the side surface (4) of the cylinder body (1), in particular the duration being dependent on the angular velocity of the cylinder body (1) and the displacement velocity of the laser emitter (600, 600").

[0039] In a seventeenth aspect according to any of the tenth to previous aspects, the operating parameters include an energy parameter representing energy emitted by the laser beam at the same portion of the side surface (4) of the cylinder body (1); In particular, the energy parameters depend on a combination of at least two of the following groups: o said at least one laser emitter control parameter (600,600") o the displacement velocity of the laser emitter (600,600") along the primary axis (Z) o said angular velocity of the cylinder body (1) around its axis of rotation (K) o The exposure time o Number of passes

[0040] In an eighteenth aspect according to any of the previous aspects, the control unit is configured to operate as the value of the difference parameter increases as follows: increasing at least one of the laser emitter control parameters (600,600"), the exposure time and the number of passes of the laser beam incident on the same portion of the side surface (4), in particular increasing the peak power of the laser beam, and / or Decreasing at least one of the angular velocity of the cylinder body (1), the displacement velocity of the laser emitter (600,600") along the main direction (Z) and the pulse duration of the laser beam.

[0041] In a nineteenth aspect according to any of the previous aspects, the control unit is configured to operate as the value of the difference parameter decreases as follows: reducing at least one of the laser emitter control parameters (600, 600"), the exposure time and the number of passes of the laser beam incident on the same portion of the side surface (4), in particular reducing the peak power of the laser beam, and / or Increasing at least one of the angular velocity of the cylinder body (1), the displacement velocity of the laser emitter (600,600”) along the main direction (Z) and the pulse duration of the laser beam.

[0042] In a twentieth aspect relating to any of the previous aspects, the differential parameter is variable according to the angular position of the cylinder body (1) and / or along the detection axis, in particular the differential parameter is variable only along the detection axis (Y).

[0043] In a twenty-first aspect according to any of the previous aspects, the difference parameter represents wear of a surface profile of the cylinder body (1).

[0044] In a twenty-second aspect according to any of the previous aspects, the difference parameter is proportional to an amount of material to be removed that is interposed between the detected surface profile (DSP) and the target surface profile (TSP).

[0045] In a twenty-third aspect relating to any of the previous aspects, the removal procedure includes the following acts. Setting predefined laser emitter control parameters. If necessary, setting the angular velocity of the cylinder body (1) about the axis of rotation (K) and / or setting the displacement speed of the contour detector (700) along the detection axis (Y). Determining or receiving as input a removal index that represents a thickness of material removed from a side (4) of the cylinder body (1) during a single pass of the laser beam. Calculating the number of passes of the laser emitter required to obtain the target surface contour (TSP) as a function of a contour difference parameter and the removal exponent, whereby if necessary, the number of passes is calculated as a ratio of the difference parameter to the removal exponent, in particular the ratio being approximated by default to an integer number.

[0046] In a twenty-fourth aspect relating to any of the previous aspects, the step of determining the removal index depends on the control parameter settings of the laser emitter, the angular velocity of the cylinder body (1) and, if necessary, the displacement speed of the contour detector (700) along the detection axis (Y).

[0047] In a twenty-fifth aspect according to any of the previous aspects, The peak power of the laser beam pulse is increased, Optionally, as the pulse duration of the laser beam decreases, The removal factor increases and the number of laser passes required to obtain the target surface profile (TSP) decreases accordingly.

[0048] In a 26th aspect according to any of the previous aspects, The peak power of the laser beam pulse is reduced, Optionally, as the pulse duration of the laser beam increases, The removal factor decreases and the number of laser passes required to obtain the target surface profile (TSP) increases accordingly.

[0049] In a 27th aspect according to any of the previous aspects, the target surface contour (TSP) defines an average diameter of the cylinder body (1) that is smaller than the individual average diameters of the cylinder bodies (1) defined by the detected surface contour (DSP).

[0050] In a 28th aspect relating to any of the previous aspects, the recovery procedure includes repeatedly performing the detection procedure and the removal procedure in a loop to define a closed loop control system, and if necessary, such a loop defines an increasing number of passes of the laser beam through the same portion of the cylinder body.

[0051] In a twenty-eighth aspect relating to any of the previous aspects, following the removal procedure, the repair procedure includes an additional detection procedure for detecting an updated detected surface contour (DSP) of the cylinder body (1) using the contour detector (700), and the updated detected surface contour (DSP) is again compared with the target surface contour.

[0052] In a twenty-ninth aspect relating to any of the previous aspects, the step of detecting the outer contour of the cylinder body (1) using the contour detector (700) includes the following steps: Rotating the cylinder body (1) angularly about its axis of rotation (K). moving the contour detector (700) along a detection axis (Y) to at least partially, in particular completely, cover a length of the outer surface of the cylinder body (1), said length being measured parallel to the axis of rotation (K) of the cylinder body (1); In particular, the rotating and translating steps may be performed in that order, in reverse order, or simultaneously.

[0053] In a thirtieth aspect according to any of the previous aspects, the control unit is configured to operate during the removal procedure as follows. Rotate the cylinder body (1). · Moving the laser emitter along the primary axis (Z). A laser beam is emitted via a laser emitter toward a work area to remove metal material from a side surface (4) of a cylinder body (1). The steps of rotating the cylinder body (1) and moving the laser emitter are performed in this order or in the reverse order or simultaneously, completely covering the surface contour of the cylinder body (1).

[0054] In a thirty-first aspect according to any of the previous aspects, the control unit is configured to perform in a specific manner, during the detection procedure and / or the removal procedure, the steps of rotating the cylinder body (1) about its rotation axis (K) and of moving the contour detector (700) along the detection axis (Y), sequentially, the step of moving the contour detector (700) is followed by the step of rotating the cylinder body (1) or vice versa, or · At the same time, the step of moving the contour detector (700) is partially or wholly simultaneous with the step of rotating the cylinder body (1).

[0055] In a thirty-second aspect relating to any of the previous aspects, the step of detecting the outer contour of the cylinder body (1) includes the step of performing the following steps successively and recursively in a loop in the following order or in reverse order: Rotating the cylinder body (1) about its axis of rotation (K) while holding the contour detector (700) stationary with respect to the detection axis (Y). Rotationally stopping the cylinder body (1) and at the same time moving the contour detector (700) along the detection axis (Y) by one or more feed steps.

[0056] In a thirty-third aspect relating to any of the previous aspects, the contour detector (700) is configured to detect representative parameters of the contour of the cylinder body (1), including at least one of the following: -Diameter of cylinder body (1) · Change in diameter of cylinder body (1) The distance between the detector and the contour of the outer surface of the cylinder body (1) The representative parameters vary according to the outer surface contour of the cylinder body (1); In particular, said representative parameters further vary with the rotation of the cylinder body (1) and / or with the position of the contour detector (700) along the detection axis (Y).

[0057] In a thirty-fourth aspect relating to any of the previous aspects, the contour detector (700) includes: At least one gauge including one or more movable arms configured to contact a side surface (4) of the cylinder body (1) with a tip of the one or more movable arms, the movable arms being configured to detect a surface contour of the cylinder body (1); or At least one non-contact distance detector configured to measure the intervening distance between the side surface (4) of the cylinder body (1). Specifically, the non-contact distance detector includes at least one between an optical detector, such as a laser, and a time-of-flight detector.

[0058] In a thirty-fifth aspect related to any of the previous aspects, the removal procedure includes making at least one first pass and one second pass, optionally making “n” passes (2≦n≦20) of the laser beam at one or more target portions of the side (4) of the cylinder body (1) to remove a predetermined amount of material during each pass.

[0059] In a thirty-sixth aspect relating to any of the previous aspects, the control unit is configured to operate as follows. · Instructing a contour detector (700) in time between said first and second passes to detect an updated contour of the cylinder body (1) in said target portion. Comparing the updated contour with a target surface contour (TSP). Adjusting the laser beam emitted by the laser emitter (600, 600") during the second pass according to said comparison between the updated contour and the target surface contour (TSP) and updating respective difference parameters, said adjustment step being dependent on said updated difference parameters.

[0060] In a thirty-seventh aspect according to any of the previous aspects, the laser emitter control parameters include at least one of the following group: The average power of the laser beam emitted by the laser emitter (600,600"). Said average power is adjustable between a minimum power (Pmin) and a maximum power (Pmax), in particular said power being measured in watts. The duration of one or more pulses of the laser beam, said laser pulse duration being adjustable between a minimum duration of a laser pulse (Tmin) and a maximum duration of a laser pulse (Tmax). Peak power of the laser beam pulse. the distance between the laser emitter (600, 600") and the outer surface of the cylinder body (1) and, if necessary, the distance intervening between the laser emitter (600, 600") and the axis of rotation (K). Said laser emitter (600, 600") is movable transversely, in particular perpendicularly, to the axis of rotation (K) along a calibration direction (X), in particular said calibration direction (X) intersecting the axis of rotation (K). · A combination of all the control parameters mentioned above.

[0061] In a thirty-eighth aspect according to any of the previous aspects, the exposure duration essentially corresponds to the sum of the durations of each of the laser beam pulses emitted on the same portion of the outer surface of the cylindrical body (1).

[0062] In a 39th aspect relating to any of the previous aspects, the energy parameter is proportional to the arithmetic product between the average power of the laser beam and the duration of one act of the laser beam on the same portion of the outer surface of the cylinder body (1).

[0063] In a fortieth aspect according to any of the previous aspects, the control unit is configured to adjust at least one of the following operating parameters: · Average or peak power of the laser emitter (600,600"). Said average or peak power is adjustable between a minimum power (Pmin) and a maximum power (Pmax), in particular said power being measured in watts. Laser beam pulse duration, said laser pulse duration being adjustable between a minimum laser pulse duration (Tmin) and a maximum laser pulse duration (Tmax). In particular, the control unit is configured to adjust both the laser emitter power (600,600") and the duration of the laser beam pulse.

[0064] In a forty-first aspect according to any of the previous aspects, the control unit is configured to define, during the removal procedure, a rough processing procedure including at least one of the following steps: Commanding a laser emitter (600, 600") to generate a pulsed laser beam, each of said pulses having an initial duration, in particular an initial duration within an order of magnitude between 1 ns and 1000 ns. Optionally, commanding a laser emitter (600,600") to generate a laser beam having a size of less than 50 μm, specifically less than 20 μm, said size being the beam diameter.

[0065] In a forty-second aspect according to any of the previous aspects, the control unit is configured to define, during the removal procedure, a semi-finishing procedure including at least one of the following steps: Commanding a laser emitter (600, 600") to generate a pulsed laser beam, each of said pulses having a second duration that is shorter than said first duration. In particular, said second duration is at least 10, 100 or 1000 times smaller than said first duration, said second duration being in particular within an order of magnitude between 1 fs and 1000 ps, ​​preferably less than 10 ps. Optionally, command the laser emitter (600,600") to generate a laser beam having a size of less than 50 μm, specifically less than 20 μm, said size being the beam diameter.

[0066] In a 43rd aspect of any of the previous aspects, the semi-finishing step follows in time the roughing step.

[0067] In a forty-fourth aspect according to any of the previous aspects, the rough machining step is configured to define a first surface roughness on the side surface (4) of the cylindrical body (1) and the semi-finishing step is configured to define a second surface roughness on the side surface (4) of the cylindrical body (1), the first surface roughness being greater than the second surface roughness, in particular the first surface roughness being greater than “n” times the second surface roughness (1.1 <n<5)。

[0068] In a 45th aspect according to any of the previous aspects, the average power of the laser emitter (600, 600") during the rough processing step is substantially the same as the average power of the laser emitter (600, 600") during the semi-finishing step, said average power being in particular between 0.5 W and 500 W, in particular between 1 W and 200 W; and / or The peak power of the laser beam emitted by the laser emitter (600, 600") during the rough machining procedure is lower than the peak power of the laser beam emitted by the laser emitter (600, 600") during the semi-finishing procedure. Said peak power of the laser beam in the rough machining procedure is 10 times, 100 times or 1000 times lower than the peak power of the laser beam in the semi-finishing procedure.

[0069] In a 46th aspect relating to any of the previous aspects, a peak power of the laser beam in the rough processing step is between 10 kW and 100 kW.

[0070] In a 47th aspect related to any of the previous aspects, the peak power of the laser beam in the semi-finishing step is between 10 kW and 10 MW.

[0071] In a 48th aspect according to any of the previous aspects from 44, The primary average surface roughness (Ra) is between 0.8μm and 2.0μm. The second average surface roughness (Ra) is between 0.2μm and 0.8μm.

[0072] In a 49th aspect according to any of the previous aspects, the laser emitter is configured to emit a laser beam having a wavelength between 0.3 μm and 1.5 μm during a rough machining procedure and / or a semi-finishing procedure.

[0073] In a 50th aspect according to any of the previous aspects, the control unit is configured to define, during the removal procedure, a finishing procedure comprising at least one of the following steps: Command the laser emitter (600,600") to generate the following types of laser beams: o Continuous type, or o A type with a pulse having the following: ■ the individual duration of the laser beam pulses emitted during the rough processing and semi-finishing steps is longer than the duration of the pulses, the duration of which, in particular during the finishing steps, is within an order of magnitude between 1 μs and 1000 ms, and / or ■ Individual peak powers smaller than the peak powers of the laser beams emitted in the rough processing step and the semi-finishing step. In particular, the peak power of the laser beam in the finishing step is 10 times, 100 times or 1000 times smaller than the power peaks of the laser beams irradiated in the rough processing step and the semi-finishing step. Optionally, command the laser emitter (600, 600") to generate a laser beam having a size larger than 100 μm, in particular larger than 200 μm, said size being in particular between 50 μm and 2000 μm, said size being the beam diameter.

[0074] In a 51st aspect relating to any of the previous aspects, the finishing procedure is configured to define an average surface roughness (Ra) of the finish on the side (4) of the cylinder body (1) of less than 0.5 μm, specifically less than 0.4 μm, specifically between 0.05 μm and 0.4 μm.

[0075] In a fifty-second aspect of any of the previous aspects, the laser emitter is configured to adjust an average laser beam power between 1 W and 2 kW, more specifically between 10 W and 1 kW, more specifically between 20 W and 800 W, more specifically between 50 W and 500 W during a finishing procedure.

[0076] In a fifty-second aspect related to any of the previous aspects, the laser emitter is configured to adjust a peak laser beam power between 8 W and 2 kW, more specifically between 10 W and 1 kW, more specifically between 10 W and 1 kW, between 20 W and 800 W, more specifically between 50 W and 500 W during a finishing procedure.

[0077] In a fifty-third aspect related to any of the previous aspects, an average power of the laser beam emitted by the laser emitter (600, 600") during the finishing procedure is greater than an average power of the laser beam emitted by the laser emitter (600, 600") during the rough processing procedure.

[0078] In a fifty-fourth aspect according to any of the previous aspects, During the rough machining procedure, the laser emitter is configured to emit a laser beam having an initial peak power Pr_p; During the semi-finishing step, the laser emitter is configured to emit a laser beam having a second peak power Ps_p; During the finishing procedure, the laser emitter is configured to emit a laser beam having a peak finishing power Pf_p, which satisfies the following condition:

number

[0079] In a fifty-fifth aspect according to any of the previous aspects, the laser emitter is configured to remove a thickness of material during a roughing procedure with each main pass that is greater than a thickness of material removed during a finishing or semi-finishing procedure.

[0080] In a 56th aspect relating to any of the previous aspects, during the rough machining procedure, the laser emitter is configured to remove a material thickness of between 0.001 mm and 0.250 mm, specifically between 0.010 and 0.100 mm, from the side (4) of the cylinder body (1) during each pass.

[0081] In a 57th aspect relating to any of the previous aspects, the laser emitter is configured to remove a thickness of material from the side (4) of the cylindrical body (1) during the removal procedure that is greater than the maximum difference between the detected surface contour (DSP) and the target surface contour (TSP), in particular greater than the maximum value of a difference parameter.

[0082] In a fifty-eighth embodiment according to any of the previous embodiments, the thickness is measured radially between a state before the removal procedure and a state after the removal procedure.

[0083] In a fifty-ninth aspect according to any of the previous aspects, the laser emitter (600, 600") is configured to emit the laser beam along a radiation direction incident on a working portion of the side surface (4) of the cylinder body (1) during an operating state, the laser beam radiation direction (LD) being substantially perpendicular or transverse to a rotation axis (K) of the cylinder body (1).

[0084] In a sixtieth aspect according to any of the previous aspects, the apparatus includes a gas nozzle (610) configured to deliver a flow of gas in the direction of a portion of a side surface (4) of the cylinder body (1) affected by the laser beam. Optionally, the side surface portion (4) is a working portion of the side surface (4) of the cylinder body (1).

[0085] In a sixty-first aspect according to any of the previous aspects, the gas nozzle (610) is configured to deliver at least one of the following: A non-oxidizing gas, in particular an inert gas, in particular said non-oxidizing gas comprising at least one of the group comprising nitrogen, helium and argon. a reactive gas configured to interact with the side surface (4) of the cylindrical body (1) to induce a chemical change in said portion of the side surface (4) of the cylindrical body (1) affected by the laser beam, said reactive gas comprising at least one of oxygen or air.

[0086] In a sixty-second aspect according to any of the previous aspects, the gas nozzle (610) is configured to deliver the gas along a gas radiation direction (GD) transverse to a laser beam radiation direction (LD), the gas radiation direction (GD) and the laser beam radiation direction (LD) intersect at a working point, in particular the working point substantially coincides with the portion of the side surface (4) of the cylinder body (1) affected by the laser beam.

[0087] In a sixty-third aspect according to any of the previous aspects, the gas flow is configured to move metal particles away from a working portion of the side (4) of the cylinder body (1) on which the laser beam is incident.

[0088] In a sixty-third aspect according to any of the previous aspects, the apparatus, in particular according to the first configuration, comprises a system of deflection mirrors suitable for directing a laser beam generated by a laser source (601) to said laser emitter by successive reflections.

[0089] In a sixty-fourth aspect according to any of the previous aspects, the apparatus includes a first and a second laser source each connected to the laser emitter by a respective cable, in particular a fiber optic cable, according to the second configuration, in particular the cable of the first laser source and the cable of the second laser source merge into the same laser emitter, The first laser light source is configured to generate a first laser beam and the second laser light source is configured to generate a second laser beam.

[0090] In aspect 64a according to any of the previous aspects, the apparatus comprises first and second laser light sources each connected by a respective deflection mirror system suitable for conveying by successive reflections a laser beam generated by the light sources to the laser emitter according to a second configuration; The first laser light source is configured to generate a first laser beam and the second laser light source is configured to generate a second laser beam.

[0091] In a sixty-fifth aspect according to the previous two aspects, the first laser beam includes at least one control parameter or wavelength different from the second laser beam.

[0092] In a sixty-sixth aspect according to any of the sixty-fourth to previous aspects, the control unit is configured to selectively drive the first or second laser light sources to emit respective laser beams to the laser emitters.

[0093] In a sixty-seventh aspect according to any of the previous aspects, the apparatus includes the laser emitter according to the third configuration and an auxiliary laser emitter separate from each other and located at different positions from each other.

[0094] In a 68th aspect of any of the previous aspects, the apparatus further comprises: A first laser source connected to said laser emitter by a respective first cable, in particular a fiber optic cable. A second laser source connected to said auxiliary laser emitter by a respective second cable, in particular a fiber optic cable. the first laser light source is configured to generate a first laser beam; the second laser light source is configured to generate a second laser beam; The laser emitter is configured to emit a first laser beam along a first radiation direction, while the auxiliary laser emitter is configured to emit a second laser beam along a second radiation direction optionally different from the first radiation direction, in particular said first emission direction and said second emission direction intersect different areas of a working location or intersect different parts of a side surface (4) of the cylinder body (1) during an operating state.

[0095] In a sixty-eighth aspect relating to the sixty-seventh aspect, the apparatus further comprises: a first laser source connected to said laser emitter by a respective first deflection mirror system suitable for directing a laser beam generated by the source to said laser emitter by successive reflections; a second laser source connected to said additional laser emitter by a respective second deflection mirror system suitable for directing the laser beam generated by the source to said additional laser emitter by successive reflections. the first laser light source is configured to generate a first laser beam; the second laser light source is configured to generate a second laser beam; In particular, the laser emitter is configured to emit a first laser beam along a first radiation direction, while the auxiliary laser emitter is configured to emit a second laser beam along a second radiation direction optionally different from the first radiation direction, in particular said first emission direction and said second emission direction intersect different areas of the working place or intersect different parts of the side surface (4) of the cylinder body (1) during an operating state.

[0096] In a 69th aspect according to any of the previous aspects from 67, the control unit is configured to simultaneously or selectively drive the first and second laser light sources to emit individual laser beams.

[0097] In a seventieth aspect, according to any of the preceding aspects, the first laser beam includes at least one control parameter or wavelength different from the second laser beam, and the control unit is configured to simultaneously or selectively drive the first and second laser light sources to emit individual laser beams; or, The first and second laser beams have the same wavelength or have equal control parameter values, in particular equal peak power and pulse duration, and the control unit is configured to simultaneously or selectively drive the first and second laser light sources to emit individual laser beams.

[0098] In a 71st aspect relating to any of the previous aspects from 67, the apparatus comprises a common laser carriage movable along a primary axis (Z) carrying a laser emitter and an auxiliary laser emitter, the laser emitter being integrated with the auxiliary laser emitter at least along the primary axis (Z).

[0099] In a seventy-second aspect according to any of the previous aspects sixty-seven to seventy, the apparatus includes first and second laser carriages (400, 400") carrying respectively the laser emitter (600) and the auxiliary laser emitter (600") according to the fourth configuration; The first carriage is movable along a main axis (Z), the second carriage is movable along a secondary axis (X') essentially parallel to the axis of rotation (K) and distinct from said main direction (Z); In particular, said first direction (X) and said first auxiliary direction (X') are angularly out of phase with each other by an angle α relative to the axis of rotation (K).

[0100] In a seventy-third aspect related to the previous aspect, the first carriage and the second carriage are movable independently of each other.

[0101] In a 74th aspect of any of the previous aspects, the apparatus includes: A detector carriage carrying a contour detector (700) and movable at least along the detection axis (Y). A laser carriage carrying a laser emitter (600,600”) and movable at least along a primary axis (Z). The detector carriage and the laser carriage are physically separate and can be moved independently of each other, in particular the primary axis (Z) and the detection axis (Y) are are separate and parallel to one another, in particular the main axis (Z) and the detection axis (Y) are not coincident, and if necessary the main axis (Z) and the detection axis (Y) are angularly offset from one another with respect to the axis of rotation (K), or - They match each other, or, The apparatus includes: o a common carriage carrying both the contour detector (700) and the laser emitter (600, 600") and moving along a working direction (W) substantially parallel to the rotation axis (K) of the cylinder body, said contour detector (700) and said laser emitter (600, 600") being integral with each other at least along the working direction (W), in particular such that a movement of the contour detector (700) along the detection axis (Y) causes an identical movement of the laser emitter (600, 600") along the main axis (Z), In particular, the main axis (Z) essentially coincides with the detection axis (Y) and the working direction (W).

[0102] In a 75th aspect relating to any of the previous aspects, the apparatus comprises a detector carriage, a laser carriage and a common rail for transporting the detector carriage and the laser carriage, the common rail extending parallel to a rotation axis (K) of the workstation, the detector carriage and the laser carriage being movable on the rail, and in particular the main direction and the detection direction substantially coincide.

[0103] In a 76th aspect relating to any of the previous aspects, the apparatus comprises a common carriage and a common rail for transporting the common carriage, the common rail extending parallel to the rotation axis (K) of the workstation, the common carriage being movable along the rail, in particular the main direction and the detection direction substantially coincide.

[0104] In a seventy-seventh aspect of any of the previous aspects, an apparatus includes a first rail and a second rail; A first rail runs parallel to the workstation's axis of rotation (K) and carries the detector carriage and the long laser carriage. The second rail runs parallel to the workstation's rotation axis (K) and carries the auxiliary laser carriage along the main auxiliary axis (X'). Optionally, the first and second rails are arranged on opposite sides of the working location of the working area, in particular the first and second rails are angularly offset or opposed to each other relative to the axis of rotation (K).

[0105] In a 78th aspect relating to any of the previous aspects, the contour detector (700) is further configured to detect surface defects on the side (4) of the cylinder body (1) by eddy current induction and / or ultrasound, the surface defects including in particular cracks, and in particular the contour detector (700) is configured to detect one or more pieces of information in the group of position, shape, size and depth of the surface defects.

[0106] In a seventy-ninth aspect related to any of the previous aspects, the laser emitter (600, 600") is configured to generate a laser beam having a wavelength between 2 μm and 0.2 μm, specifically between 1.2 μm and 0.25 μm, more specifically between 1.1 μm and 0.3 μm, or between 1.1 μm and 0.5 μm.

[0107] In an eightieth aspect according to any of the previous aspects, the laser emitter (600, 600") is configured to emit a class 4 laser beam.

[0108] In an 81st aspect relating to any of the previous aspects, the apparatus includes a shielding cover (1000) defining an internal space that accommodates at least a workstation and a laser emitter, and optionally a contour detector (700), the shielding cover (1000) configured to confine the laser beam within the internal space and prevent the laser beam from escaping.

[0109] In an 82nd aspect relating to any of the previous aspects, the internal space of the shield cover (1000) is in communication with the external environment substantially only via a filter device configured to prevent leakage of metal dust generated by the removal procedure from the internal space to the surrounding environment.

[0110] In an 83rd aspect relating to any of the previous aspects, the workstation includes at least one motor or actuator, such as an electric motor or actuator, configured to place the cylinder body (1) in a rotating state and operably connected to a control unit, the control unit being configured to control the motor to vary the rotational speed of the cylinder body (1) during the detection procedure and / or during the removal procedure.

[0111] In an eighty-fourth aspect of any of the previous aspects, the workstation includes at least one motor or actuator, such as an electric motor or actuator, configured to move the common carriage.

[0112] In an eighty-fifth aspect of any of the previous aspects, the workstation includes at least one motor or actuator, such as an electric motor or actuator, configured to move the first carriage.

[0113] In an eighty-sixth aspect of any of the previous aspects, the workstation includes at least one motor or actuator, such as an electric motor or actuator, configured to move the second carriage.

[0114] In an eighty-seventh aspect of any of the previous aspects, the workstation includes at least one motor or actuator, such as a motor or an electric actuator, configured to move the contour detector.

[0115] In an 88th aspect of any of the previous aspects, the control unit is configured to perform a detection procedure simultaneously with the removal procedure, and during the repair procedure, the laser emitter (600, 600") is configured to emit a laser beam at a first portion of the side (4) of the cylinder body and the contour detector is configured to detect a surface contour at a second portion of the side (4) of the cylinder body, the first portion being separate and distinct from the second portion.

[0116] In an eighty-ninth aspect of any of the previous aspects, the laser emitter is a solid-state laser emitter comprising at least one of the following group: Disk laser emitter Fiber laser emitter Nd:YAG laser emitter ·Yb:YAG laser emitter Nd:YVO4 laser emitter Diode laser emitter ·Titanium sapphire laser emitter

[0117] In a ninetieth embodiment according to any of the previous embodiments, the cylinder body (1), in particular at least the side surface (4) of the cylinder body (1), is made of a metallic material, in particular steel.

[0118] In a ninety-first aspect according to any of the previous aspects, the cylinder body (1) has a working side dimension in length along the axis of rotation (K) between 500 mm and 2500 mm, and a diameter between 50 mm and 1500 mm.

[0119] In a 92nd aspect relating to any of the previous aspects, the control unit is configured to calculate a target surface contour (TSP) according to the detected surface contour (DSP), and if the target surface contour (TSP) intersects with the detected surface contour (TSP), the control unit is configured to calculate a new target surface contour (TSP) that does not intersect with the detected surface contour (DSP), in particular the new target surface contour (TSP) defines a diameter of the cylinder body that is smaller than the diameter defined by the target surface contour (TSP) that intersects with the detected surface contour (DSP).

[0120] In a ninety-second aspect relating to any of the previous aspects, the control unit is configured to operate as follows. On a first portion of the side surface (4) of the cylinder body, a temporary detection surface contour (DSP temp ) to detect. Temporary detection surface contour (DSP temp ) according to the temporary target surface contour (TSP temp ) and calculating the temporary target surface contour (TSP temp ) is the temporary detection surface contour (DSP temp ) does not intersect. Detecting an updated detection surface contour (DSP) on a second portion of the side surface (4) of the cylinder body. The temporary target surface contour (TSP temp Calculating an updated target surface contour (TSP) according to the updated detected surface contour (DSP) if the updated detected surface contour (DSP) intersects with the updated detected surface contour (DSP), and the updated target surface contour (TSP) does not intersect with the updated detected surface contour (DSP).

[0121] In a 93rd aspect of any of the previous aspects, the control unit is configured to emit a pulsed laser beam having a peak power that is greater than the relative average power, specifically, a peak power that is 10 times, 100 times, or 1000 times greater than the relative average power.

[0122] In a 94th aspect relating to any of the previous aspects, the step of detecting the surface contour of the side surface (4) of the cylinder body (1) includes the following steps. Maintaining the cylinder body (1) fixed in an angular position. a step of moving a contour detector (700) along a detection axis (Y) while the cylinder body is fixed at the angular position, the contour detector (700) simultaneously detecting a surface contour of a portion of the side surface (4) of the cylinder body while moving along the detection axis (Y). Positioning and fixing the contour detector (700) at a predetermined detection position along the detection axis (Y). a step of moving the cylinder body (1) in a rotational state about its rotation axis (K) and detecting the surface contour of the additional portion of said side surface (4) of the cylinder body (1) while the contour detector (700) is in said predetermined detection position.

[0123] In a 95th aspect relating to any of the previous aspects, the default detection position includes: A first end position in which the contour detector (700) faces a first end of the side surface of the cylinder body (1). A second end position in which the contour detector (700) faces a second end of the side of the cylinder body (1) opposite the first end along the direction defined by the axis of rotation (K). An intermediate position in which the contour detector (700) faces a central portion of the side surface of the cylinder body (1), specifically an intermediate position located centrally between the first end and the second end.

[0124] In a 96th aspect according to any of the previous aspects, the side surface (4) of the cylinder body (1) is configured to perform a rolling action during an operating state of the cylinder body.

[0125] In a 97th aspect according to any of the previous aspects, the side surface (4) of the cylinder body (1) defines a maximum diameter of the cylinder body (1).

[0126] In a 98th aspect related to any of the previous aspects, the target surface profile (TSP) includes required machining tolerances, and the machining tolerances specifically include the following tolerances: Equal to ±30 μm measured across the diameter of the cylinder body, if the cylinder body is configured to perform hot rolling operations (HSM); or Between ±10 μm and ±15 μm measured across the diameter of the cylinder body when the cylinder body is configured to perform cold rolling operations (CRM).

[0127] In a ninety-ninth aspect according to any of the previous aspects, the control unit is configured to calculate a deviation value representing a difference between the detected surface contour (DSP), in particular the updated detected surface contour (DSP), and the target surface contour (TSP); If said deviation value is within a predetermined tolerance range, the control unit is configured to terminate the repair procedure. If said deviation value is outside said predetermined tolerance range, the control unit is configured to continue executing a remedial procedure. In particular, said tolerances are as follows: Equal to ±30 μm measured across the diameter of the cylinder body, if the cylinder body is configured to perform hot rolling operations (HSM); or Between ±10 μm and ±15 μm measured across the diameter of the cylinder body when the cylinder body is configured to perform cold rolling operations (CRM).

[0128] In a hundredth aspect according to any of the previous aspects, the apparatus includes a system of reflective mirrors interposed between a laser source and individual laser emitters, the mirror system configured to guide a laser beam emitted by the laser source to the individual laser emitters. The laser source is configured to emit a pulsed laser beam having a duration of less than 100 fs, specifically between 0.1 fs and 100 fs, specifically between 1 fs and 50 fs.

[0129] In a 101 st aspect according to any of the previous aspects, the removal step defines a cylinder body grinding step (1).

[0130] In a 102nd aspect according to any of the previous aspects, the control unit (15) is configured to command at least one laser emitter (600, 600") to emit a pulsed laser beam suitable for removing material from the cylinder body (1) during the removal procedure (2002).

[0131] In a 103rd embodiment of any of the previous embodiments, the removing step (2002) includes: A step (2002a) of moving at least one between said cylinder body (1) and said at least one laser emitter (600, 600"), optionally placing the cylinder body (1) in a rotational state about its axis of rotation (K). · Commanding (2002b) at least one laser emitter (600, 600") to emit said pulsed laser beam, said pulses being capable of removing material from the cylinder body (1).

[0132] In a 104th aspect related to any of the previous aspects, the steps of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") and commanding the at least one laser emitter (600, 600") to emit a pulsed laser beam (2002b) are substantially simultaneous with each other.

[0133] In a 105th aspect according to any of the previous aspects, the pulses of the laser beam are arranged to be offset in time from one another.

[0134] In a 106th aspect relating to any of the previous aspects from 102, each pulse directed to a side (4) of the cylindrical body (1) is configured to define an individual laser footprint (40) on said side (4) of the cylindrical body (1) during said operating state of the apparatus.

[0135] In a hundred and seventh aspect according to any of the previous aspects, the laser pulses define laser footprints that at least partially overlap one another by forming respective overlapping portions (41) between the laser footprints.

[0136] In a 108th aspect of any of the previous aspects, the removing step (2002) includes the steps of: a step (2002a) of moving at least one between said cylinder body (1) and said at least one laser emitter (600, 600"), and optionally placing the cylinder body (1) in rotation about its axis of rotation (K). · commanding (2002b) at least one laser emitter (600, 600") to emit a pulsed laser beam, said laser pulses removing material from the cylinder body (1). The laser beam pulses are offset in time from one another. In particular, the steps of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") and commanding the at least one laser emitter (600, 600") to emit a pulsed laser beam are substantially simultaneous with each other.

[0137] In a 109th aspect relating to any of the previous aspects, each pulse directed at a side (4) of the cylinder body (1) defines an individual laser footprint on the side (4) of the cylinder body (1), the laser pulses defining laser footprints (40) that at least partially overlap each other by forming individual overlapping portions (41) between the laser footprints (2002c).

[0138] The 110th embodiment relates to an apparatus (10) for the surface treatment of cylinder bodies (1), in particular for the surface restoration of rolling cylinders, said apparatus comprising: a workstation (100) defining at least one operating position configured to receive, in an operating state (10) of the device, a cylinder body (1) having a side surface (4), the workstation (100) being configured to support the cylinder body (1) in rotation according to a predetermined axis of rotation (K); at least one laser emitter (600, 600") configured for cooperating with the workstation (100) and for emitting at least one pulsed laser beam in the direction of said working location, said at least one laser emitter (600, 600") being movable at least along a main axis (Z) substantially parallel to the rotation axis (K) of the cylinder body (1); a control unit (15) operatively connected to the laser emitter (600, 600"), the control unit (15) being configured to perform at least one repair procedure (2000) on a side surface (4) of a cylinder body (1) during an operational state of the device, The repair procedure (2000) includes a removal procedure (2002) including the steps of: o moving (2002a) at least one between the cylinder body (1) and said at least one laser emitter (600, 600"); o commanding at least one laser emitter (600, 600") to emit said pulsed laser beam, said pulses configured to remove material from the cylindrical body (1) (2002b). the laser beam pulses are offset in time from one another; each pulse directed at a side surface (4) of the cylindrical body (1) is configured to define an individual laser footprint (40) on said side surface (4) of the cylindrical body (1) during said operating state of the apparatus; The laser pulses define laser footprints (40) that at least partially overlap one another by forming respective overlapping portions (41) between the laser footprints.

[0139] A 111th aspect relates to a method (1) for surface repair of a cylinder body, comprising performing a procedure (2002) of removing material from the cylinder body, said removal procedure (2002) comprising emitting (2002b) successive laser pulses towards a side surface (4) of the cylinder body (1), each laser pulse defining (2002c) a respective laser footprint on said side surface (4) of the cylinder body (1), said laser pulses defining laser footprints (40) that at least partially overlap each other by forming respective overlapping portions (41) between said laser footprints.

[0140] In a 112th aspect related to the previous 111th aspect, the repair method is performed by an apparatus (10) according to any of the previous aspects.

[0141] In a 113th aspect according to any of the previous aspects from 111, the step of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") and the step (2002b) of commanding the at least one laser emitter (600, 600") to emit a pulsed laser beam are substantially simultaneous with each other.

[0142] In a 114th aspect relating to any of the previous aspects from 107, the overlapping portion (41) extends over a surface area of ​​between 10% and 90%, optionally between 25% and 75%, of the surface area of ​​the laser footprint (40), and optionally the surface area of ​​the overlapping portion (41) is between 50% and 75%, or between 25% and 50%.

[0143] In a 115th aspect relating to any of the aspects 102 to the previous, the laser beam pulses are arranged with a time shift from one another and define a pulse frequency between 10 kHz and 10,000 kHz, more specifically between 10 kHz and 1500 kHz, as necessary.

[0144] In a 116th aspect according to any of the previous aspects from 106, the laser footprint (40) defines an area and its boundaries of material removal from the cylinder body (1).

[0145] In a 117th aspect according to any of the previous aspects from 102, the step of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") includes a step of placing the cylinder body (1) in a rotational state about its rotation axis (K).

[0146] In a 118th aspect according to any of the previous aspects 107 to 118, the overlapping portion is defined by at least partial overlap of laser footprints that are contiguous with one another, in particular directly contiguous with one another.

[0147] In a 119th aspect according to any of the previous aspects, the overlapping portion is defined by an overlap of a first laser print and a second laser print that immediately successive in time to the first laser print.

[0148] In a 120th embodiment of any of the previous embodiments, the second laser footprint is defined with a time delay from the first laser footprint equal to the inverse of the pulse frequency.

[0149] In a 121st aspect according to any one of the previous 119th and 120th aspects, the control unit (15) performs the following steps during the removal procedure: Command the rotation of the cylinder body (1) around the axis of rotation (K) at a predetermined speed, commanding at least one laser emitter (600, 600") to emit a first laser pulse to define said first laser imprint on the cylinder body; configured to command at least one laser emitter (600, 600") to emit a second laser pulse to define said second laser imprint on the cylinder body; the second laser imprint partially overlaps the first laser imprint; the second laser pulse is immediately successive in time to the first laser pulse; In particular, a second laser pulse is emitted with a time delay relative to the first laser pulse equal to the inverse of the laser pulse frequency.

[0150] In a 122nd aspect according to any of the previous aspects from 119, the control unit (15) is configured to, during the removal procedure: commanding at least one laser emitter (600, 600") to emit a third laser pulse that temporally follows the first laser pulse and the second laser pulse to define a third laser imprint on the cylinder body that overlaps the second laser imprint and is external to or in contact with the first laser imprint; or, configured to command at least one laser emitter (600, 600") to emit a third laser pulse temporally subsequent to said first laser pulse and said second laser pulse to define a third laser imprint on the cylinder body partially overlapping said second laser imprint and said first laser imprint.

[0151] In a 123rd aspect of the previous aspect, a third laser pulse is immediately successive in time to the second laser pulse.

[0152] In a 124th aspect according to any of the previous 112 and 123 aspects, the third laser pulse is emitted with a time delay relative to the second laser pulse equal to the reciprocal of the pulse frequency.

[0153] In a 125th aspect according to any of the 1 to the previous aspects, the apparatus includes a vibration system configured to determine a spatial oscillation of a direction of a laser beam emitted by at least one laser emitter (600, 600") at a certain oscillation frequency.

[0154] In a 126th aspect relating to any of the previous aspects, the vibration frequency is between 10 Hz and 20,000 Hz, specifically between 100 Hz and 10,000 Hz, more specifically between 200 Hz and 5,000 Hz, and even more specifically between 200 Hz and 2,000 Hz.

[0155] In a 127th aspect according to any of the previous aspects, the laser beam is a pulsed laser beam.

[0156] In a 128th aspect relating to any of the previous aspects from 125, the spatial vibration specifies the vibration amplitude of the laser beam on the side (4) of the cylinder body (1) to be between 0.05 mm and 5 mm, specifically between 0.1 mm and 2 mm, as necessary.

[0157] In a 129th aspect according to any of the previous aspects from 125, the control unit (15) is configured to drive the vibration system during the removal step (2002) to determine a spatial oscillation of the laser beam direction.

[0158] In a 130th aspect according to any of the previous aspects from 125, the removing step (2002) includes performing the following steps substantially simultaneously with each other: A step of moving the cylinder body (1) in a rotating state. Determining the spatial oscillation of the laser beam direction by the oscillation system. Commanding at least one laser emitter (600,600") to emit a laser pulse.

[0159] In a 131st aspect according to any of the previous aspects from 125, the control unit (15) is configured to determine a vibration frequency of the vibration system as a function of the rotation speed of the cylinder body, or vice versa.

[0160] In a 132nd aspect according to any of the previous aspects from 125, the device includes a rotation speed detector configured to detect a rotation speed of the cylinder body (1), and the control unit (15) determining a vibration frequency of the vibration system as a function of the rotational speed of the cylinder body detected by a speed detector, or configured to determine a rotational speed of the cylinder body as a function of a vibration frequency of the vibration system.

[0161] In a 133rd aspect according to any one of the previous aspects from 125, the control unit (15) As the rotation speed of the cylinder body increases, the vibration frequency of the vibration system increases, and Configured to reduce the vibration frequency of the vibration system as the rotational speed of the cylinder body decreases.

[0162] In a 134th aspect according to any of the previous aspects from 125, a spatial oscillation of the laser beam direction determined by the oscillation system defines a movement of the laser beam along a predetermined trajectory.

[0163] In a 135th aspect of the previous aspect, the default trajectory includes at least one of a circular trajectory, a straight trajectory, a curved trajectory, and an elliptical trajectory.

[0164] In a 136th aspect relating to any of the previous aspects from 125, the vibration system is configured to move the laser beam along a vibration direction substantially parallel to the rotation axis (K) of the cylinder body (1), and in particular, is configured to define a vibration amplitude of the laser beam at the side (4) of the cylinder body (1) substantially parallel to the rotation axis (K) of the cylinder body (1).

[0165] In a 137th aspect relating to any of the previous aspects from 125, in order to obtain the overlap portion (41) between the laser footprints, the control unit (15) is configured to determine a vibration frequency of the vibration system as a function of at least one of the following: A one-dimensional representative parameter (D) of said laser footprint (40). Laser pulse frequency (f pulse ) The oscillation amplitude (L) of the laser pulse on the side surface (4) of the cylinder body (1)

[0166] In a 138th aspect according to any one of the previous aspects from 125, the control unit (15) Decreasing the vibration frequency as the representative parameter (D) of the size of the laser footprint (40) decreases; Optionally, the vibration frequency is configured to increase as a representative parameter (D) of the size of the laser footprint (40) increases.

[0167] In a 139th aspect according to any of the previous aspects from 125, the control unit (15) is configured to determine a vibration frequency of the vibration system according to the following formula to obtain the overlap portion (41):

number

[0168] In a 140th aspect related to any of the previous and / or 110th aspects, at least one laser emitter (600, 600") is configured to direct a laser beam to a focal point, said focal point defining a minimum spatial dimension of the laser beam, in particular, a light beam defining the laser beam converging at said focal point.

[0169] In a 141st aspect related to the previous aspect, at least one laser emitter (600, 600") is configured to define said focal point at a blur distance (Δf) from a predetermined reference plane by a side surface (4) of the cylindrical body (1) during an operating state of the device.

[0170] In a 142nd aspect according to the previous aspect, the blur distance (Δf) is a non-zero value.

[0171] In a 143rd aspect relating to any of the 141 to the previous aspects, the blur distance (Δf) is between 0.01 mm and 2 mm in absolute value, specifically between 0.1 mm and 1 mm, and more specifically between 0.1 mm and 0.5 mm.

[0172] In a 144th aspect according to any of the previous aspects 141 to 144, at least one laser emitter (600, 600") is configured to vary the blur distance (Δf) between: · If the focal point is outside the cylinder body, then the blur distance (Δf) has a positive value. · Negative value of said blur distance (Δf) when the focal point is inside the cylinder body.

[0173] In a 145th aspect according to any of the previous aspects from 102, the frequency of the laser pulses is greater than the rotational frequency of the cylindrical body (1), optionally wherein said rotational frequency of the cylindrical body is defined as the number of complete rotations per second of the cylindrical body (1) around the rotation axis (K).

[0174] In a 146th aspect according to any of the previous aspects from 102, the frequency of the laser pulse is at least “n” times greater than the rotational frequency of the cylinder body (1), where n>100, particularly n>500, more particularly n>1000, and even more particularly n>3600.

[0175] In a 147th aspect relating to any one of the 102 to previous aspects, the rotation frequency of the cylinder body (1) is between 5 RPM and 250 RPM, and is between 20 RPM and 100 RPM as necessary.

[0176] In a 148th aspect according to any of the previous aspects from 102, the control unit (15) determines, in response to a desired surface area of ​​the overlapping portion, Calculate and command the frequency of the laser beam pulses, Configured to calculate and command the rotation speed or frequency of the cylinder body (1).

[0177] In a 149th aspect according to any of the previous aspects from 102, the control unit (15) is configured to operate during the removal procedure (2002) as follows. Receiving as input or calculating a desired surface area of ​​overlap. Calculating the pulse frequency of the laser beam and the rotation speed or frequency of the cylinder body (1) according to the desired surface area of ​​the overlapping portion (41). · performing a repair procedure (2000), in particular a removal procedure (2002), by setting said laser beam pulse frequency and said rotation speed of the cylinder body.

[0178] In a 150th aspect according to any of the previous aspects 106 to 150, the laser footprint (40) has a shape within the group including: circular, elongated circular, elliptical, curved with a convex contour.

[0179] In a 151st aspect relating to any of the previous aspects from 106, the control unit (15) is configured to set a shape of a laser footprint of the laser footprint by changing at least one of the following: a laser beam pulse duration defining said laser footprint; the rotation speed of the cylinder body around the rotation axis (K) during the emission of said laser pulses Laser beam oscillation frequency - Laser beam shape as required

[0180] In a 152nd aspect according to any of the previous aspects from 107, the control unit (15) is configured to operate as follows during the removal procedure (2002): Receiving as input a desired surface area of ​​the overlap or a ratio of the surface area of ​​the overlap (41) to the surface area of ​​the laser footprint (40). According to said desired surface area of ​​the overlap or said ratio, calculating at least one of the following: Peak Power o Average power of the laser beam pulse o Rotation speed of the cylinder body, frequency of the laser pulse or, · Receive as input the peak pulse power from the beam. Calculating the surface area of ​​the overlap, or a ratio of the surface area of ​​the overlap to a surface area of ​​the laser footprint, as a function of the peak pulse power from the laser beam. or, · Receive the rotational speed of the cylinder body as input. Optionally, receiving a laser pulse frequency as an input. Calculating the surface area of ​​the overlapping portion (41) or the ratio of the surface area of ​​the overlapping portion (41) to the surface area of ​​the laser footprint (40) as a function of the rotational speed of the cylindrical body (1) and, if necessary, the frequency of the laser pulses. or, · Receiving as input the peak power of a laser beam pulse. Receiving the rotational speed of the cylinder body (1) as an input. Calculating a frequency of the laser beam pulses between 10 kHz and 10,000 kHz, more specifically between 310 kHz and 1,500 kHz, as a function of the peak power of the received laser beam pulses and the rotational speed of the cylinder body (1), to achieve a surface area of ​​the overlapping portion (41) that is between 10% and 90%, more specifically between 25% and 75%, of the surface area of ​​the laser footprint (40).

[0181] In a 153rd aspect according to any of the previous aspects from 107, the control unit (15) is configured to operate as follows. · Receiving as input the desired maximum surface roughness of the cylinder body. Calculating at least one of the following depending on the desired maximum surface roughness: o the surface extent of the overlapping portion, and optionally a range of values ​​for said surface extent o The relationship between the surface area of ​​the overlapping portion (41) and the surface area of ​​the laser footprint (40)

[0182] In a 154th aspect related to any of the previous aspects, the control unit (15) is configured to operate as follows. Calculating at least one of the following according to said surface area of ​​the overlap or said ratio: o Peak power of the laser beam pulse o Average power of the laser beam pulse o Rotational speed of the cylinder body o Laser pulse frequency

[0183] In a 155th embodiment related to any of the previous 153rd and 154th embodiments, the maximum surface roughness is between 0.05 μm and 3.0 μm.

[0184] In a 156th embodiment according to any of the previous embodiments 107 to 158, the surface area of ​​the overlapping portion is between 10% and 90%, in particular between 25% and 75%, of the surface area of ​​the laser footprint.

[0185] In a 157th aspect relating to any of the 102 to previous aspects, the peak power of the laser beam pulse is between 5 kW and 1000 kW, specifically between 100 kW and 500 kW.

[0186] In a 158th aspect relating to any of the 102 to previous aspects, the rotation speed of the cylinder body is between 5 RPM and 250 RPM, and optionally between 20 RPM and 100 RPM.

[0187] In a 159th aspect of the present invention, the laser footprint is less than 70 μm. 2 ~20000μm 2 , 500μm as required 2 ~5000μm 2 has a surface area of

[0188] In a 160th aspect according to any of the previous aspects 111 to 160, the method for surface repair of a cylinder body is a method for grinding a side surface (4) of the cylinder body (1).

[0189] In a 161st aspect relating to any of the previous aspects from 111, the method includes a repair step (2000) of at least one side (4) of the cylinder body (1), optionally the repair step (2000) being in accordance with any of the aspects 1 to 101.

[0190] In a 162nd aspect according to the previous aspect, the repair procedure (2000) includes the removal procedure (2002) including the steps of: o moving (2002a) at least one between the cylinder body (1) and said at least one laser emitter (600, 600"); o commanding at least one laser emitter (600, 600") to emit said pulsed laser beam, said pulses configured to remove material from the cylindrical body (1) (2002b). The laser beam pulses are offset in time from one another.

[0191] In a 163rd aspect related to any of the previous aspects, the moving step (2002a) of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") and the step (2002b) of commanding the at least one laser emitter (600, 600") to emit a pulsed laser beam are substantially simultaneous with each other.

[0192] In a 164th aspect relating to any of the previous aspects 107 to 164, each overlap between the overlapping portions (41) extends over a surface area of ​​between 10% and 90%, optionally between 25% and 75%, optionally between 50% and 75%, or between 25% and 50% of the surface area of ​​the laser footprint.

[0193] In a 165th aspect according to any of the previous aspects from 102, each laser pulse causes the formation of a crater on the side (4) of the cylinder body (1).

[0194] In a 165th aspect according to the previous aspect, the crater is 70 μm 2 ~20000μm 2 The surface area of

[0195] In a 167th aspect related to any of the previous 165 and 166 aspects, the crater corresponds to the laser footprint (40), for example in terms of location and / or shape.

[0196] In a 168th embodiment according to any of the previous embodiments, the crater has a surface area substantially equal to the laser footprint (40).

[0197] In a 169th aspect according to any of the previous aspects from 102, each laser pulse causes the formation of a crater on the side surface (4) of the cylindrical body (1), said crater exhibiting a depth between 1 μm and 20 μm.

[0198] In a 170th aspect relating to any of the previous aspects from 107, an overlapping portion (41) generated by partial overlap of the first laser pulse and the second laser pulse causes the formation of a crater on the side (4) of the cylinder body (1), the crater exhibiting a depth between 10 μm and 100 μm.

[0199] In a 171st aspect according to any of the previous aspects from 102 and / or from 110 and 111, the cylinder body (1) is a rolling cylinder made of a metallic material, in particular a metallic material including steel or cast iron.

[0200] In a seventy-second embodiment according to any of the previous embodiments, the side surface (4) of the cylinder body is made of a metallic material, in particular a metallic material including steel or cast iron.

[0201] In a 173rd aspect relating to any of the aspects 111 to the previous aspect, the repair method is carried out using an apparatus (10) relating to any of the aspects 102 to 110.

[0202] In a 174th embodiment according to the second embodiment, the repair method is according to any one of the first to seventy-second embodiments. [Brief description of the drawings]

[0203] Certain embodiments and aspects of the present invention are described below with reference to the accompanying drawings, which are provided for purposes of illustration and therefore not limitation.

[0204] [Figure 1] FIG. 1 is a top view of an apparatus according to the present invention. [Diagram 2] FIG. 1 is a top view of an apparatus according to the present invention. [Diagram 3] FIG. 1 is a top view of an apparatus according to the present invention. [Figure 4] FIG. 1 is a top view of an apparatus according to the present invention. [Diagram 5] 1 is a schematic diagram showing the difference between a detected contour and a target contour of a side surface of a cylinder body. [Figure 6a] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6b] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6c] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6d] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6e] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6f] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6g] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6h] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6i] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6j] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6k] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6l] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6m] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6n] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6o] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 6p] FIG. 1 is a schematic diagram of successive steps of the removal procedure. [Figure 7]7a and 7b are schematic diagrams of the peak and average power emitted by a continuous or pulsed laser beam as a function of time. [Figure 8] 1 illustrates diagrammatically the method steps according to the invention; [Figure 9] 9a, 9b and 9c show schematic diagrams of a laser beam incident on the side of a cylindrical body, with focal points positioned at various heights Δf. [Figure 10] 1 shows a schematic representation of an apparatus according to the invention supporting a cylindrical body with overlapping laser imprints; [Figure 11] 13 shows diagrammatically an apparatus according to a further embodiment of the invention for supporting a cylinder body with overlapping laser footprints; [Figure 12] 13 shows diagrammatically an apparatus according to a further embodiment of the invention for supporting a cylinder body with overlapping laser footprints; [Figure 12b] 1 illustrates a schematic diagram of an apparatus according to an embodiment of the invention supporting a cylinder body with overlapping laser imprints that define a serpentine trajectory; [Figure 13] 1 shows a flowchart depicting method steps of a repair procedure that includes defining overlap between laser footprints. [Figure 14] 1 shows a flow chart depicting method steps of a repair procedure that includes both detecting the outer contour of the cylinder body and defining the overlap between the laser footprints. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0205] The cylinder body surface treatment device 1 is designated in the attached table by reference number 10 and is intended in particular for the surface restoration of rolling / laminate cylinders. The device can be configured to perform grinding operations on the side of the laminated cylinders.

[0206] The cylinder body 1, or laminated cylinder 1, shown diagrammatically in Figs. 1 to 4, may have a side surface length between 500 mm and 2500 mm, and a diameter between 50 mm and 1500 mm. The cylinder body may be made of a metallic material, such as steel or cast iron.

[0207] The cylinder 1 has a side surface 4 extending along the axis of rotation K. The side surface 4 defines the part of the cylinder body which is active in the rolling phase, in other words the side surface 4 defines the part of the cylinder body which is intended for the lamination process.

[0208] The cylinder body is placed in a workstation defined by a support structure 100 configured to rotatably support the cylinder body 1 about a rotation axis K during one of its grinding steps or external surface treatment.

[0209] The cylinder body 1 is supported in the workstation 100 by supports 200 that allow rotation of the cylinder 1 about its axis of rotation K. In one embodiment shown in Fig. 1, the apparatus includes first and second supports 200, 200', defining a tip and tailstock system that axially supports the cylinder to be machined. In particular, the first and second supports 200, 200' are axially aligned along a direction that coincides with the axis of rotation K of the cylinder body when the cylinder body is accommodated in the workstation 100.

[0210] In an alternative embodiment, the cylinder is supported on a neck 6 which defines the area of ​​the cylinder and which usually has a smaller diameter than the side surface 4, on which bearings are mounted for inserting the cylinder into the rolling mill. In this case, the cylinder support may be via plain bearings.

[0211] In a further alternative embodiment, the cylinder is supported on a shoulder 7 axially interposed between the side surface 4 and the neck 6. In particular, the shoulder 7 has a diameter intermediate between the diameter of the neck of the cylinder body and the diameter of the side surface 4. Here, the neck 6 has the smallest diameter.

[0212] In other words, according to the embodiment described above, the workstation 100 is configured to support the cylinder body and enable or define its rotation about the axis of rotation K. In particular, the workstation 100 defines a working location suitable for accommodating the cylinder body 1.

[0213] The apparatus may also include a motor 300 (shown in FIG. 1 ) operably connected to the cylinder body and configured to rotate the cylinder body 1 about a rotation axis K during the side grinding step 4.

[0214] The apparatus also includes at least one laser emitter 600, 600″ configured to cooperate with the workstation 100 and to emit at least one laser beam in the direction of a working location 10 in which the cylinder body 1 is accommodated.

[0215] Specifically, a laser emitter 600,600'' is connected via an optical fiber 602,602'' to a laser source 601,601'' configured to generate a laser beam and direct it via the optical fiber to the laser emitter.

[0216] In an alternative embodiment, not shown, the 600,600″ laser emitter is connected to the 600,600″ laser source via a reflecting mirror system suitable for transporting the beam from the laser source to the laser emitter by successive reflections. In this case, the optical fiber is replaced by an air path for the laser beam, protected in a suitable passage. In particular, the device comprises a reflecting mirror system in an embodiment in which the laser source is configured to emit a pulsed laser beam having a duration of less than 100 femtoseconds, in particular between 0.1 femtoseconds and 100 femtoseconds, in particular between 1 femtosecond and 50 femtoseconds. The applicant points out that the transmission of the pulsed laser beam benefits from the presence of a reflecting mirror instead of a fiber optic cable, when the pulse width has a pulse duration in the femtosecond range. As will become clear later, the mirror system can be used during the semi-finishing stage.

[0217] The laser source is primarily solid-state (e.g., fiber, disk, Nd:YAG, Yb:YAG, Nd:YVO4, diode) with continuous or pulsed laser beam emission. The type of laser source may be determined according to the type of grinding to be performed on the cylinder body 1.

[0218] Pulsed laser beams with durations of the order of ns (nanoseconds), ps (picoseconds) or fs (femtoseconds) can be used for ablation-based processes. The laser pulses can be emitted at frequencies between 1 kHz and 50 MHz, with wavelengths close to infrared (e.g., wavelengths of about 1 μm) or visible light (e.g., wavelengths of about 0.5 μm) or close to ultraviolet (wavelengths of about 0.3 μm). The average power of the laser beam is moderate, typically greater than 1 W, for example, 50-200 W, whereas the peak power of the laser beam pulses is quite high, typically greater than 10 kW and may even be up to more than 1 MW.

[0219] Lasers with continuous or modulated radiation with long pulses (μs-ms or longer) can be used to perform full cylinder or localized polishing processes (crack repair).

[0220] A pulsed laser can be used for the cleaning process (laser cleaning) to remove oxides, debris and impurities either globally or locally on the cylinder.

[0221] The details of the control parameters used to perform the laminate cylinder grinding are described in more detail below.

[0222] All processes may be coupled to a beam shaping system with a vibrating beam or a beam shaped for large area processing with a dynamic system.

[0223] FIG. 7a shows the output power Pout of a continuous laser beam, while FIG. 7b shows the output power of a pulsed laser beam. In particular, the dashed line defines the average power of the laser beam. In the case of a continuous laser beam, this dashed line corresponds to a constant power of the laser beam. In the case shown in FIG. 7b, the laser beam has a peak power Pout p and the average power P m The laser is emitted in pulses that define a peak power, with a peak power greater than the average power. For the same average power, a continuous laser always emits an average power, whereas a pulsed laser emits a series of short pulses, which, averaged over time, defines an average power equivalent to that of a continuous laser. However, the present invention shows that a high peak power, compared to the average power, is particularly suitable for causing evaporation / ablation of the metallic material of the cylinder body. For the same total energy and average power emitted by the laser, a continuous laser beam and a pulsed laser beam produce different results. A continuous laser beam or a laser beam with pulses of very long duration tends to melt the material locally and is therefore considered to be more suitable for finishing processes. In contrast, a short pulse laser beam with a high power peak tends to sublimate the material and is therefore considered to be more suitable for removal / rough machining / semi-finishing operations.

[0224] The amount of material removed is related to the peak power, so that for the same average power, as the pulse duration decreases, more material is removed.

[0225] The laser emitter 600, 600″ is disposed along an operating base that houses the cylinder body and is movable at least along a main axis Z that is substantially parallel to the rotational axis K of the cylinder body 1. When the cylinder body 1 is housed in the operating location, the laser emitter is configured to move substantially parallel to the side 4 of the cylinder body 1.

[0226] The apparatus may include a carriage 400 and a respective rail, on which the carriage 400 is movable along a primary axis Z. A laser emitter is carried and tethered to the carriage 400 for movement along the primary axis Z, as shown in FIG.

[0227] The apparatus may also include a sled 500 carried and constrained by the carriage 400 and movable along a direction transverse to the main axis Z. In particular, the sled 500 may carry a laser emitter 600, 600″ and allow it to be moved closer to or further away from the side surface 4 of the cylinder body. Such transverse movement relative to the cylinder body changes the position of the focal point of the laser beam emitted by the laser emitter relative to the surface of the cylinder, following the contour of the surface to be machined and accommodating the positioning of the laser emitter 600, 600″ relative to cylinder bodies of various diameters.

[0228] Movement of carriage 400 and slide 500 may preferably be accomplished by linear electric actuators or motors, or other types of actuators (such as motors and ball screws with high precision in terms of displacement and high responsiveness to commands given by a control system).

[0229] As mentioned above in the prior art section, the side surfaces of the cylinder body tend to wear during the rolling stage, such as during rolling of a metal semi-finished product, e.g. a metal strip, which causes the side surfaces of the cylinder body to crack, deform or work harden, resulting in the need to grind the side surfaces of the cylinder body.

[0230] In this regard, the device includes at least one contour detector 700 shown in Figures 1 to 4, which is configured to detect the contour of the side of the cylinder body. In other words, such contour detector 700 is configured to detect defects in the surface of the cylinder body and determines the points where the laser beam needs to be applied and how to apply the laser beam. The contour detected by the detector 700 is referred to as the detected surface contour DSP.

[0231] The contour detector 700 is movable at least along a detection axis Y substantially parallel to the rotation axis K of the cylinder body 1 and detects the contour along the entire length of the side of the cylinder body 1. The contour detector 700 may comprise a gauge including one or more movable arms configured to contact the side 4 of the cylinder body 1 with a tip attached at the end of each of the movable arms. Such arms define a probe that traces the contour of the side 4 of the cylinder body as it moves according to the changes in the contour of the side 4 of the cylinder body. Alternatively, the contour detector 700 may comprise a non-contact distance detector configured to measure the intervening distance with the side of the cylinder body 1. In particular, the non-contact distance detector may comprise an optical detector, such as a laser, or a time-of-flight detector.

[0232] In particular, the contour detector can detect the change in height of the side surface 4 due to the change in diameter of the cylinder body.

[0233] More specifically, the contour detector 700 is configured to detect a representative parameter of the contour of the cylinder body 1, including at least one of the diameter of the cylinder body 1, the change in the diameter of the cylinder body 1, or the intervening distance between the detector and the contour of the side of the cylinder body 1. The representative parameter varies depending on the condition of the outer contour of the cylinder body 1.

[0234] It should also be noted that the representative parameters of the outer contour may vary as a function of the angular position of the cylinder body 1 and the position of the contour detector 700 along the detection axis Y. In particular, the surface contour of the cylinder body includes altitude measurement parameters that vary as a function of the angular position of the cylinder body 1 and / or the linear position along the detection axis Y.

[0235] Advantageously, the contour detector 700 may be complemented by an auxiliary defect detector 800 suitable for detecting surface defects on the side surface of the cylinder body. Such an auxiliary defect detector 800 may include, for example, an eddy current inductor and / or an ultrasonic emitter suitable for determining the location, shape and size (including depth) of localized surface defects such as cracks, dents, etc.

[0236] Conveniently, a profilometer may also be provided for measuring the roughness of the cylinder surface. Such a profilometer may be of the contact type touch probe or of the non-contact type.

[0237] The apparatus may include an auxiliary carriage 410 and a respective rail, the auxiliary carriage 410 being movable along the rail along the detection axis Y. The contour detector 700, and optionally the auxiliary defect detector 800, if present, and / or the roughness inspector, may be carried by the auxiliary carriage 410 and constrained to move along the primary Y axis, as shown in FIG.

[0238] For example, in one embodiment shown in accompanying Figures 1-4, the detection axis Y may coincide with the primary axis Z of the 600 laser emitter.

[0239] Furthermore, the device 10 may include a distance meter 620 configured to detect the intervening distance between the laser emitter 600, 600″ and the surface of the cylinder to be processed. That is, the distance between the laser emitter and the side surface 4 of the cylinder body 1 affects the effectiveness of the laser to remove the metal material, since the focal position of the laser with respect to the cylinder surface changes with this distance. If the distance between the laser emitter and the side surface 4 of the cylinder body 1 is found to be outside of a predetermined range, the laser can be moved closer or farther away from the cylinder body, either manually or by an actuator, for example an electric actuator. Furthermore, the control unit can be configured to detect the intervening distance between the laser and the cylinder body, compare it with a target distance, and command the actuator to move the laser emitter closer or farther away depending on the comparison. Such distance correction may be performed before starting the cylinder body grinding procedure, or it may be performed during the grinding operation to update the position of the laser emitter as the diameter of the cylinder body changes.

[0240] The apparatus may also include a gas nozzle 610 adjacent to the laser emitter 600 and configured to generate a gas flow in the direction of the part of the cylinder body 1 on which the laser beam is incident. Conveniently, the gas is a non-oxidizing gas, for example an inert gas such as nitrogen, helium or argon. Alternatively, a reactive gas such as oxygen can be used to achieve a chemical change in the surface affected by the laser beam.

[0241] The gas nozzle is configured to emit said gas during an operating state of the device, in particular when the laser emitter emits a laser beam onto the cylinder body 1 .

[0242] The apparatus may further comprise a cover structure 1000 including side and top walls for defining a working area and a containment volume for the cylinder body 1. The cover structure 1000 defines a safety barrier within the containment volume configured to contain an operational laser beam, for example, class 4. It should be noted that the laser beam, if not contained, may pose a significant risk to human health.

[0243] The cover structure 1000 also includes a vacuum system 20 configured to suck the material removed during grinding of the cylinder body. Indeed, laser grinding generates very fine metal dust that can cause evaporation of the metal material and be harmful to human health. The suction system 20 is therefore configured to determine an air flow suitable for sucking such dust during grinding conditions. The suction system may include one or more filters suitable for retaining such dust. Furthermore, the presence of the gas nozzle 610 would contribute to the diffusion of metal dust and increase the risk level to human health if the device were not equipped with a cover structure.

[0244] The above description includes the major components and major features of the device 10. However, the device 10 can be configured according to a variety of different embodiments relative to one another, each of which is consistent with the present invention and concepts thereof.

[0245] 1 shows an initial configuration, where the apparatus comprises a single laser source 601 connected to a single laser emitter 600 via an individual fiber optic cable 602 or via a suitable reflecting mirror system (not shown). Moreover, in such an embodiment, the laser emitter 600 and the contour detector 700 are independently movable along the main axis Z, as they are carried by the carriage 400 and the auxiliary carriage 410, respectively. According to the first configuration, the laser emitter is independently movable relative to the contour detector 700, so that the laser beam acts on the side surface 4 of the cylinder body, regardless of the position that the contour detector takes along the main axis Z.

[0246] FIG. 2 shows a second configuration, where the device comprises a first laser source 601 and a second laser source 601″, both of which are connected to the same laser emitter 600 by individual fiber optic cables 602, 602″ or by individual reflecting mirror systems (not shown). Preferably, the second laser source 601″ is of a different type than the first laser source 601, allowing a wider range of processes to be performed by driving either the first or the second laser source, increasing the flexibility of the device. For example, the first laser source can be configured to perform a rough material removal process, while the second laser source can be configured to perform a surface finishing process. In this configuration, it is generally possible to change the type of process during multiple passes of the carriage 400. However, due to the presence of a single laser 600 emitter, two different types of processes cannot be performed simultaneously.

[0247] Furthermore, in the second configuration, as in the first configuration, the laser emitter 600 and the contour detector 700 are independently movable along the main axis Z, since they are carried by the carriage 400 and the auxiliary carriage 410, respectively. According to the second configuration, the laser emitter is independently movable with respect to the contour detector 700. This allows the laser beam to act on the side surface 4 of the cylinder body, regardless of the position that the contour detector takes along the main axis Z.

[0248] FIG. 3 shows a third configuration, in which the device 10 includes: A first laser source 601 connected to a first laser emitter 600 by a respective optical fiber cable 602 (or by a respective reflecting mirror system (not shown)). A second laser source 601″ connected by a respective fiber optic cable 602″ (or by a respective reflecting mirror system (not shown)) to a second laser emitter 600″ separate from the first laser emitter 600.

[0249] In particular, it should be noted that the first and second laser emitters 600, 600" are carried by a common carriage 400 moving along the primary axis Z and are offset from one another along the primary axis Z, such that the laser beam of the first laser emitter 600 engages a different portion of the cylinder body 1 than the laser beam of the second laser emitter 600". For example, the first and second laser emitters may be arranged parallel and spaced apart and coupled to the same common carriage 400, as shown in FIG. 3.

[0250] The second laser source 601″ may be of a different type than the first laser source 601. In this way, by driving either the first laser source or the second laser source, a wider range of processes can be performed, increasing the flexibility of the apparatus 10. For example, the first laser source can be configured to perform a rough material removal process, while the second laser source can be configured to perform a surface finishing process. Thus, in this third configuration, unlike the second configuration, it is possible to perform two different processes during a single pass of the laser beam, thereby reducing the time required for processing.

[0251] Alternatively, the first and second laser sources can be of the same type and directed at different areas of the cylinder body, as shown in Figure 3. In this way, two similar processes can be performed during a single pass of the laser beam, thereby reducing the time required for processing.

[0252] Furthermore, in the third configuration, as in the first and second configurations, the first and second laser emitters 600, 600" are movable along the main axis Z independently of the contour detector 700, as they are carried by the carriage 400 and the auxiliary carriage 410, respectively. This allows the two laser beams to act on the side 4 of the cylinder body regardless of the position of the contour detector along the main axis Z. However, the first and second laser emitters 600, 600" are constrained to each other and are mounted on the same common carriage 400.

[0253] FIG. 4 shows a fourth configuration, in which the device 10 includes: A first laser source 601 connected to a first laser emitter 600 by a respective optical fiber cable 602 (or by a respective reflecting mirror system (not shown)). A second laser source 601″ connected by a respective fiber optic cable 602″ (or by a respective reflecting mirror system (not shown)) to a second laser emitter 600″ separate from the first laser emitter 600.

[0254] It should be noted in particular that according to the fourth configuration, the first laser emitter 600 is carried by the first carriage 400 and the second laser emitter 600" is carried by a second carriage 400" that is separate and distinct from the first carriage 400. The first carriage 400 is movable along a main axis Z, while the second carriage 400" is movable along a secondary axis Z" that is parallel to the rotation axis K of the cylinder body 1 and parallel to the main axis Z of the first carriage.

[0255] According to the fourth configuration, the laser beam of the first emitter 600 engages a different part of the cylinder body 1 than the part engaged by the laser beam of the second emitter 600". For example, the first and second laser emitters may be opposite each other or angularly offset from the rotation axis K. In the fourth configuration, the first laser emitter 600 is movable along the primary axis Z independently of the movement of the second laser emitter 600" along the secondary axis Z".

[0256] On the auxiliary carriage 400" there is an auxiliary slide 500" which is movable along an axis X" transverse or perpendicular to the cylinder body. A second laser emitter 600" is rigidly coupled to the auxiliary slide 500" so that it too can be moved towards or away from the cylinder body 1.

[0257] According to the fourth configuration, the first laser source 601 may be the same as the second laser source 600 and may be configured in the same way. Thus, the first and second emitters can simultaneously perform the same type of treatment on the cylinder body at different parts of the side surface 4. Alternatively, according to the fourth configuration, the first laser source 601 may be different from the second laser source 600 or may be configured differently. For example, the first laser source may emit a laser beam having different control parameters, such as peak or average power or pulse duration, than the laser beam emitted by the second laser source. Thus, the first and second emitters can simultaneously perform different types of treatment.

[0258] Similar to above, the apparatus according to the fourth configuration includes an auxiliary nozzle 610" for blowing gas in the direction of the laser beam impingement zone on the side of the cylinder body. Finally, there is an auxiliary distance meter 620" configured to detect the intervening distance between the second laser emitter 600" and the cylinder surface to be machined.

[0259] According to the fourth configuration, it is possible to perform, with one apparatus, two different types of laser processing operations, for example requiring two different types of lasers, by optimizing the speed of the laser moving along the cylinder surface. Indeed, in general, the carriages 400 and 400″ are independent of each other and can move at different speeds along the main axis Z and the auxiliary axis Z″, respectively. The control unit is then configured to move the first and second laser emitters 600, 600″ independently in order to reduce the processing time.

[0260] According to the above description, the apparatus 10 may include a vibration system configured to determine a spatial oscillation of the direction of the laser beam 12 emitted by the laser emitter 600, 600″ at a vibration frequency. The vibration frequency may be between 10 Hz and 20000 Hz, more preferably between 100 Hz and 10000 Hz, more particularly between 200 Hz and 2000 Hz, more particularly between 200 Hz and 2000 Hz.

[0261] The oscillation system is then configured to define the apparent spatial shape of the laser beam 12. For example, the apparent spatial shape of the laser beam, i.e. the trajectory of its oscillation, may be elongated straight line, circular, elliptical, oval or rectangular as a result of said oscillation. The oscillation of the laser beam may be determined by vibrating one or more lenses or mirrors on which the laser beam is incident, i.e. the lenses and / or mirrors may be moved by piezoelectric actuators. Alternatively, the oscillation system may include a deformable mirror.

[0262] A sufficiently high oscillation frequency of the laser beam (e.g. in the range of several hundreds of Hz) allows an apparent action zone of the laser beam such that the material is processed with an apparent shape of the laser beam similar to the shape of the scanning trajectory, for example.

[0263] The vibration system may be configured to redirect the laser beam along a single axis, thereby defining a laser beam having a linear apparent shape. Alternatively, the vibration system may be configured to redirect the laser beam along two axes, thereby defining a laser beam having a two-dimensional apparent shape. In this case, the apparent shape of the laser beam may be circular, elliptical, triangular, rectangular, etc.

[0264] The vibration frequency may be fixed during the repair procedure 2000, for example, during the entire removal procedure 2002.

[0265] Alternatively, the control unit 15 of the device 10 may be configured to vary the vibration frequency during the removal procedure 2002, for example according to the rotational or tangential speed of the cylinder body 1. In particular, the control unit 15 may be configured to increase the vibration frequency when the speed of the cylinder body increases. Furthermore, the control unit 15 may be configured to decrease the vibration frequency when the speed of the cylinder body decreases.

[0266] Such a vibration system may cause a translation of the laser beam at the side surface 4 of the cylinder body 1 of 0.05 mm to 5 mm, more particularly 0.1 mm to 2 mm, during the operating state of the device. For example, the spatial oscillation of the laser beam determined by the vibration system defines a movement of the laser beam along a predefined trajectory, which may include at least one of a circular trajectory, a linear trajectory, a curved trajectory or an elliptical trajectory. For example, the vibration system may be configured to move the laser beam along a trajectory substantially parallel to the axis of rotation of the cylinder body, as shown in Fig. 12b.

[0267] The vibration system may be combined with a constant emission laser beam, for example either a time-constant laser beam, or a pulsed emission laser beam.

[0268] In one embodiment, the 600,600" laser emitter can be configured to direct the laser beam towards a focal point 11, as shown in Figures 9a, 9b and 9c. In other words, the 600,600" laser emitter can focus the beams constituting the laser beam substantially towards a single point defined by said focal point 11. The power density of the laser beam, i.e. the normalized power per unit area, is maximum at the focal point and decreases as the distance from the focal point 11 increases. In effect, the laser beam concentrates its entire power at the focal point 11.

[0269] The focal point thus defines the smallest spatial dimension, and more specifically, the smallest cross-sectional dimension, of the laser beam, whereas the surface cross-sectional area of ​​the laser beam increases with increasing distance from the focal point 11. Outside the focal point 11, the laser beam power is in fact distributed over a gradually increasing surface area.

[0270] The 600,600" laser emitter is configured to define a focal point 11 at a blurred distance Δf with respect to a reference plane defined by the side surface 4 of the cylinder body 1 during the device operating state. The focal points and the corresponding blurred distances Δf are shown diagrammatically in Fig. 9a, 9b and 9c. It will be noted that, as shown in Fig. 9b, when the focal point 11 is on the side surface 4, the blurred distance Δf is zero. In contrast, when the focal point 11 is not on the side surface 4, the blurred distance Δf has a non-zero value. More specifically, according to Figs. 9a and 9c, a blurred distance Δf>0 indicates a focal point that is outside the cylinder body 1, and a blurred distance Δf<0 indicates a focal point that is inside the cylinder body 1. In other words, the focal point Δf>0 is interposed between the 600,600" laser emitter and the side surface 4 of the cylinder body. In contrast, the focal point Δf<0 is interposed between the side surface 4 of the cylinder body 1 and the rotation axis K of the cylinder body.

[0271] During the removal procedure 2002, the control unit 15 can be configured to instruct the laser emitter to define a blur distance Δf between +2 mm and −2 mm, more specifically between +1 mm and −1 mm, even more specifically between +0.5 mm and −0.5 mm. More specifically, the blur distance Δf is between 0.01 mm and 2 mm, more specifically between 0.1 mm and 1 mm, even more specifically between 0.1 mm and 0.5 mm.

[0272] As previously discussed, the control unit 15 can be configured to command the laser emitters 600, 600'' to emit a pulsed laser beam 12 during the removal procedure 2002. These laser pulses will remove material from the cylinder body 1, enabling grinding of the cylinder body 1, where specifically the cylinder body 1 is a rolled cylinder. In such a configuration, the removal procedure 2002 includes: Moving at least one between the cylinder body 1 and the laser emitter 600, 600″ (2002a); The laser emitter 600, 600″ is commanded to emit a pulsed laser beam towards the operating location of the workstation, specifically, the laser pulses are directed towards the side surface 4 of the cylinder body 1 (2002b).

[0273] According to a preferred embodiment, the step of moving at least one between the cylinder body 1 and the laser emitter 600, 600″ comprises rotating the cylinder body 1 around its axis of rotation K. Alternatively, the apparatus may be arranged such that the cylinder body 1 is fixed and the laser emitter is movable around the cylinder body 1.

[0274] The laser beam pulses are arranged with a time offset from one another to define a laser pulse frequency, specifically, the frequency of the laser pulses can be between 10 kHz and 10,000 kHz, more specifically, between 10 kHz and 1500 kHz.

[0275] Each laser pulse directed at the side surface 4 of the cylinder body 1 is configured to define an individual laser footprint 40 on the side surface 4 of the cylinder body 1 during the operating state of the apparatus, in particular during the removal procedure 2002. The laser footprint can define an area of ​​the side surface 4 of the cylinder body 1 and its boundaries where material is removed from the cylinder body 1. In other words, the laser pulse 10 removes metal material from the side surface 4 of the cylinder body substantially in said laser footprint 40 and defines a crater having a depth relative to the side surface 4 of the cylinder body.

[0276] The laser footprint 40 may have a shape within the group between a circle, an elongated circle, an ellipse, and a curve with a convex contour. The shape of the laser footprint may vary as a function of the duration of the laser beam pulse that defines the laser footprint, the energy of the laser beam pulse, the rotation speed of the cylinder body about the axis of rotation K during emission of the laser pulse, or the shape of the laser beam.

[0277] Laser imprint: 70μm 2 ~20000μm2 This surface extent of the laser beam 12 can be altered by commanding the laser emitter to vary the focus by moving the focus further away from or closer to the side 4 of the cylinder body.

[0278] According to the embodiment illustrated in FIGS. 10-12 and with respect to the method steps of FIGS. 13 and 14, the laser pulses define laser footprints 40 that at least partially overlap one another by forming respective overlapping portions 41 between the laser footprints 40. Each overlapping portion 41 preferably extends over a surface area of ​​between 10% and 95% of the surface area of ​​the laser footprint 40, and more preferably between 20% and 75%. In one configuration, the removal procedure 2002 may include defining portions of the overlay having a surface area of ​​between 50% and 75% of the surface area of ​​the laser footprint 40. Alternatively, the removal procedure 2002 may include defining overlapping portions having a surface area of ​​between 20% and 50% of the surface area of ​​the laser footprint 40. In certain embodiments, the removal procedure 2002 may include defining overlapping portions having a surface area substantially equal to 50% of the surface area of ​​the laser footprint 40. Indeed, it should be noted that since the cylinder body is rotating and the laser pulses are aligned with a time offset from one another, successive laser footprints will engage different parts of the side surface 4 of the cylinder body 1 (partially overlapping each other, as shown diagrammatically in Figures 10-12).

[0279] More specifically, overlapping portion 41 is defined by a partial overlap of laser footprints 40 that are contiguous with one another, specifically immediately consecutive with one another. By immediately consecutive with one another, it is meant that if a first laser pulse and a second laser pulse were arranged offset in time by a duration equal to the inverse of the laser pulse frequency, the second laser pulse would produce a second laser print that partially overlaps the first footprint produced by the first pulse.

[0280] In an optional configuration, a third pulse subsequent to and distinct from the first and second laser pulses may create a third laser imprint that overlaps the second laser imprint but is external to the first laser imprint. This configuration is shown in Figures 11 and 12 for illustrative purposes and is not intended to be limiting.

[0281] Alternatively, the present invention can also provide that, assuming three laser pulses as mentioned above, i.e. a first pulse, a second pulse and a third pulse, the third laser imprint produced by the third pulse may be partially superimposed on both the first and the second laser imprint. Such an embodiment having three laser imprints partially superimposed on each other is not shown in the attached drawings due to obvious graphical representation problems.

[0282] At the same laser pulse frequency, the surface coverage of each overlapping portion 41 depends on the relative speed between the laser beam and the cylinder surface and is further given by the rotation speed of the cylinder body 1, i.e. the rotation frequency of the cylinder body, in combination with the oscillation speed of the beam, i.e. the oscillation frequency, if present. The rotation frequency of the cylinder body means the number of complete revolutions around the axis of rotation K per unit time, e.g. between 5 RPM and 50 RPM in the presence of laser beam oscillation or between 50 RPM and 250 RPM in the absence of laser beam oscillation. The oscillation frequency means the number of complete oscillations in a unit time achieved by the oscillation system. Similarly, the vibration frequency refers to the number of complete vibrations in a unit time achieved by the laser beam. During the removal procedure 2002, the control unit 15 can be configured to command a rotation speed or a rotation frequency of the cylinder body 1, such as a rotation speed between 5 RPM and 250 RPM. Optionally, during the removal procedure 2002, the control unit 15 may be configured to command a vibration speed or a vibration frequency of the laser beam, such as a vibration frequency between 10 Hz and 20000 Hz, in particular between 100 Hz and 10000 Hz, more particularly between 200 Hz and 21000 Hz.

[0283] At the same frequency of laser pulses, as the relative velocity between the laser beam and the cylinder surface increases, the surface area of ​​each overlapping portion decreases. Conversely, at the same frequency of laser pulses, as the relative velocity between the laser beam and the cylinder surface decreases, the surface area of ​​each overlapping portion increases (41).

[0284] The surface area S of overlapping portion 41 can be defined as a percentage of the surface area of ​​laser footprint 40 by the following formula:

number

[0285] To generate a continuous overlap therebetween, the frequency of the laser pulses is preferably greater than the rotation frequency of the cylinder body, if any, and the oscillation frequency of the beam, in particular the frequency of the laser pulses may be "n" times greater than the rotation frequency of the cylinder body 1, where n>100, in particular n>500, optionally n>1000, even more particularly n>3600. Furthermore, the frequency of the laser pulses may be at least "m" times greater than the oscillation frequency of the beam, where m>10, in particular m>50, optionally m>100, even more particularly m>360.

[0286] Based on the above, the extent of the overlap is closely related to the pulse frequency of the laser beam, the relative speed between the laser beam and the cylinder surface (given by a combination of the rotation speed or frequency of the cylinder body 1 and the vibration speed or frequency, if any, of the laser beam). In one configuration, depending on the desired surface extent of the overlap, the control unit 15 can be configured to operate as follows: Calculate and command the frequency of the laser beam pulse. Calculate and command the relative velocity between the laser beam and the surface of the cylinder body 1.

[0287] Specifically, the control unit 15 can be configured to operate as follows. · Receive as input or calculate the desired surface area of ​​overlap. Depending on the desired surface area of ​​the overlap 41, calculate: o the pulse frequency of the laser beam, and o Relative velocity between the laser beam and the surface of the cylinder body · Executing a removal procedure 2002 by setting the laser beam pulse frequency and the relative velocity between the laser beam and the surface of the cylinder body.

[0288] For example, the relative velocity between the laser beam and the surface of the cylinder body can be determined by the rotational speed of the cylinder body about the rotation axis K in combination with the vibration frequency of the laser beam as commanded by the vibration system.

[0289] The control unit 15 may be configured to calculate a peak laser beam power and / or an average laser beam power during the removal procedure 2002 depending on the desired surface coverage of the overlap. More specifically, the control unit 15 can be configured to operate as follows. Receives as input the desired surface area of ​​the overlap. Calculating at least one of the following depending on the desired surface area of ​​the overlap: peak power and / or average pulse power of the laser beam, the relative speed between the laser beam and the surface of the cylinder body, and the frequency of the laser pulses.

[0290] For example, the control unit 15 may be configured to receive as input the desired surface area of ​​the overlap and set the peak power of the laser beam, the relative speed between the laser beam and the surface of the cylinder body, and the frequency of the laser pulses.

[0291] Alternatively, the control unit 15 can be configured to operate as follows. The peak pulse power from the beam is received as input. Calculate the surface area of ​​the overlap according to the peak pulse power from the laser beam. The repair procedure 2000, specifically the removal procedure 2002, is executed to set the surface area of ​​the overlapping portion 41.

[0292] In a further embodiment, the control unit 15 may be configured to operate as follows. Receive as input the relative velocity between the laser beam and the surface of the cylinder body. Optionally, receive the laser pulse frequency as input. Calculate the surface area of ​​the overlap as a function of the relative speed between the laser beam and the surface of the cylinder body, and optionally the frequency of the laser pulse.

[0293] In a further embodiment, the control unit 15 may be configured to operate as follows. A peak power of a laser beam pulse is received as an input. Receive as input the relative velocity between the laser beam and the surface of the cylinder body. Calculate a laser beam pulse frequency between 10 kHz and 10,000 kHz to achieve an overlap surface area of ​​20% to 90% of the laser footprint surface area, and 25% to 75% if necessary, as a function of the peak power of the laser beam pulse and the relative speed between the laser beam and the surface of the cylinder body.

[0294] This description also points out that the percentage of overlap between two laser footprints influences the surface roughness of the cylinder body obtained at the end of the repair procedure. In particular, a very high value of the percentage of overlap between two successive laser footprints can induce damage to the cylinder surface, while an excessive reduction of the same percentage (or even a negative value of this percentage) can lead to an incomplete or rough treatment of the cylinder body. The control unit 15 of the device 10 of the invention can be configured to calculate the surface area of ​​the overlap or the ratio of the surface area of ​​the overlap to the surface area of ​​the laser footprint as a function of the desired maximum surface roughness.

[0295] Once the surface area or percentage of the overlap is calculated, the control unit 15 may calculate at least one of the rotation speed of the cylinder body and the frequency of the laser pulses to obtain the surface area or percentage of the overlap. For example, the control unit 15 may calculate both the rotation speed of the cylinder body and the frequency of the laser pulses to obtain the calculated surface area of ​​the overlap.

[0296] Further, the control unit 15 can be configured to calculate at least one between the peak power of the laser beam pulse and the average power of the laser beam pulse depending on the surface area of ​​the overlapping portion or a ratio thereof, pre-calculated as a function of the desired roughness.

[0297] The desired maximum surface roughness may be between 0.05 μm and 3.0 μm.

[0298] The surface area of ​​the overlap may be between 10% and 95% of the surface area of ​​the laser footprint.

[0299] The peak power of the laser beam pulse may be between 5 kW and 1000 kW.

[0300] The rotation speed of the cylinder body may be between 5 RPM and 250 RPM, optionally between 20 RPM and 100 RPM.

[0301] It should also be noted that according to one embodiment of the repair procedure 2000, whose flowchart is shown in FIG. 13, the repair procedure 2000 of the device 10 may include a step of defining an overlap portion 41 between the footprints of at least two lasers 40, without the repair procedure 2000 necessarily including a detection step 2001.

[0302] Furthermore, the extent of the overlap 41 may depend on the oscillation frequency of the laser beam 12, which is determined by the oscillation system. Indeed, it should be noted that in order to obtain an overlap 41 between successive laser 40 footprints, the frequency of the laser pulses 12 must be related to the oscillation frequency of the laser beam and the surface extent of the laser footprints.

[0303] To obtain the overlapping portion 41, the average laser beam displacement velocity V osc is the pulse frequency f according to the following formula: imp and a parameter D representing the laser footprint size 40.

number

[0304] If the laser footprint 40 has a circular shape, the parameter D corresponds to the diameter of the laser footprint.

[0305] Specifically, based on the above formula, the control unit 15 can be configured to determine the vibration frequency of the vibration system to obtain the overlapping portion 41 according to the following formula:

number

[0306] For example, the control unit 15 can be configured to change the vibration frequency depending on the size of a single crater of material removed by a single laser pulse. The smaller the crater, the lower the vibration frequency required to obtain the overlap 41. More specifically, to obtain the overlap 41 between various successive laser 40 footprints, the control unit 15 can be configured to determine the vibration frequency of the vibration system as a function of the size D of the laser 40 footprint, the frequency of the laser pulses, and the vibration amplitude of the laser pulses. For example, the control unit 15 can be configured to decrease the vibration frequency as the dimension D of the laser footprint 40 decreases. Also, with the vibration frequency fixed, the control unit 15 can be configured to increase the size D of the laser footprint 40 as the vibration amplitude of the laser beam increases to obtain the overlap 41. Similarly, to obtain the overlap 41, the control unit 15 can be configured to increase the vibration frequency as the size of the laser footprint 40 increases to obtain the overlap 41.

[0307] Therefore, as shown in Figure 12b, it is noted that the distance Z between the first and second laser footprints depends on the pulse frequency of the laser beam, the vibration frequency, and the vibration amplitude of the laser beam. Specifically, the Z distance can be calculated by the following formula:

number

[0308] Fig. 12b shows an embodiment of the device 10 in which the vibration system is configured to move the laser beam along a vibration direction substantially parallel to the rotation axis K of the cylinder body 1. The rotation of the cylinder body during the removal procedure, in combination with the movement of the laser beam along a vibration direction substantially parallel to the rotation axis K of the cylinder body 1, gives rise to a unique serpentine path of the laser footprint on the side surface 4 of the cylinder body 1, in particular a symmetrical zigzag path. In particular, a zigzag path is defined as a broken line forming a succession of angles, in fact a zigzag path is a shape described by a line interrupted by alternating continuation in opposite directions at a constant angle.

[0309] (Cylinder body repair procedure 20001) The invention also relates to a repair procedure 2000 of the side surface 4 of the cylinder body 1, carried out by the previously described device 10, by emitting a laser beam suitable for removing material from the side surface 4 of the cylinder body 1. The steps of the repair procedure described below are controlled by the control unit 15 of the device and can be synchronized with each other. Moreover, these steps define the relative method for repairing / rectifying the side surface of the cylinder body by the action of the laser beam.

[0310] The repair procedure comprises a detection procedure 2001 which comprises at least the step of detecting a detected surface contour DSP of the cylinder body 1 using a contour detector 700 according to what has been described in the previous section and as illustrated diagrammatically in figures 5 and 6. The detected surface contour DSP of the cylinder body 1 defines the wear contour of the rolling cylinder which has to be machined to be within the tolerances of the rolling machine.

[0311] The control unit may be configured to move the contour detector 700 along the detection axis Y and simultaneously use the contour detector 700 to detect the surface contour DSP along the detection axis Y. The control unit may also be configured to associate geometrical features of the detected surface contour DSP of the cylinder body 1 with respective linear positions along the detection axis Y to define a surface contour map of the cylinder body. Moving the contour detector 700 along the detection axis Y thus enables the surface contour of the cylinder body to be detected along a substantially straight line.

[0312] If necessary, the control unit is configured to rotate and move the cylinder body 1 about a rotation axis K. For example, the control unit may drive an electric motor operably connected to the cylinder body to rotate the cylinder body 1 at a predetermined angular velocity. The control unit may then be configured to detect the DSP surface contour using a contour detector 700, which moves along a detection axis Y as the cylinder body rotates.

[0313] The movement of the contour detector 700 parallel to the axis of rotation of the cylinder body in combination with the angular movement of the cylinder body 1 allows the generation of a surface contour depending on the linear position of the contour detector 700. The surface contour is thus not affected by the tendency of a single longitudinal section of the cylinder body side, but is averaged along the rotation of the cylinder body during the contour acquisition. In other words, the average value is selected from all points detected during a complete rotation of the cylinder and at various angular positions corresponding to the appropriate circumference of the Y coordinate, allowing the simultaneous measurement of the roundness and eccentricity errors along the cylinder table.

[0314] The control unit can be configured to move the contour detector 700 along the detection axis Y while the cylinder body is fixed at an angular position, then rotate the cylinder body one step to define a new angular position, and detect the contour along the detection axis Y while the cylinder body is fixed at the new angular position.

[0315] Similarly, the control unit can be configured to perform the reverse procedure, i.e. to rotate the cylinder body and simultaneously detect the surface contour using the contour detector 700, and then move the contour detector 700 one step along the detection axis Y to define a new linear position of the detector.

[0316] In an alternative embodiment, the control unit can be configured to first move the contour detector 700 along the detection axis Y while the cylinder body is fixed at an angular position, and then rotate the cylinder body at a predetermined angular velocity, and simultaneously detect the surface contour by the contour detector 700 at a predetermined Y-axis position (e.g., the end of the table and its central portion, etc.).

[0317] In an alternative embodiment, the control unit can command the rotation of the cylinder body and the linear movement of the contour detector 700 along the Y axis to occur simultaneously. In this case, the control unit is configured to associate each geometric feature of the DSP-detected surface contour of the cylinder body with a respective linear position of the contour detector 700 and, if necessary, with a respective angular position of the cylinder body 1.

[0318] The detection procedure also includes a step of comparing the detected DSP surface contour with the TSP target surface contour of the cylinder body 1. The TSP target surface contour is the contour that is aimed to be obtained in the restoration procedure after grinding. It will be noted that in general, the TSP target surface contour defines an average diameter of the cylinder body 1 that is smaller than the individual average diameter of the cylinder body 1 defined by the detected surface contour DSP. In other words, between the TSP target surface contour and the detected surface contour DSP there is a certain thickness of material to be removed, which the restoration procedure needs to remove so that the TSP target surface contour appears.

[0319] The control unit may be configured to calculate the TSP target surface contour or may be configured to receive the TSP target surface contour as an input. If the control unit is configured to calculate the TSP target surface contour, the control unit is configured to detect an initial surface contour, inspect for defects, cracks or localized surface damage, and define a TSP target surface contour at a depth relative to the detected surface contour that is greater than the maximum depth of defects or cracks present on the side. Figure 6a illustrates this concept diagrammatically, where in response to an initial minor defect CR1, the control unit calculates a temporary target surface contour TSD highlighted by a dashed line. temp The temporary target surface contour TSD is defined as: temp However, during a further detection step, the contour detector detects a temporary target surface contour TSD deeper than the first defect CR1. temp A second defect CR2 may be detected that intersects with the temporary target surface contour TSD temp cannot completely remove the second surface defect CR2. The control unit is then configured to update the target contour and define a new target contour TSP, which is located at a depth relative to the detected surface contour that is greater than the maximum depth defined by the second defect CR2. In this way, by removing the to-be-removed material intervening between the detected surface contour and the new target surface contour TSD, it is possible to completely remove the defect CR2 as well.

[0320] In other words, the control unit is configured to define a target surface contour in response to the detected surface contour, and if the target surface contour intersects with the detected surface contour, the control unit is configured to reduce a diameter of the cylinder body defining the target surface contour.

[0321] The target surface contour is considered final only after the contour detector and the defect detector (if present) have completed their contour (and defect, if present) detection operations on the entire side surface 4 of the cylinder body.

[0322] Analogous to what has been described with respect to the detected surface contour DSP of the cylinder body 1, the target surface contour TSP of the cylinder body 1 comprises at least one geometric feature which varies as at least one function between the angular position of the cylinder body 1 and its linear position along the detection axis Y. The geometric features of the target surface contour TSP comprise at least one individual target altitude parameter which represents the diameter of the cylinder body 1 and / or the variation of said diameter of the cylinder body 1 and / or the distance intervening between the side surface 4 of the cylinder body 1 and the contour detector 700 during the operating state and during the subsequent removal procedure.

[0323] A comparison between the detected surface contour DSP and the target surface contour TSP defines a difference parameter DP. Specifically, as shown in Fig. 5 and Fig. 6a, the difference parameter is defined by a comparison between an altitude parameter of the detected surface contour DSP and an altitude parameter of the target surface contour TSP. The difference contour parameter DP represents the difference or ratio between the detected surface contour DSP and the target surface contour TSP, as shown in Fig. 6a. In other words, the DP difference parameter represents the amount of material to be removed that is interposed between the detected surface contour DSP and the TSP target surface contour.

[0324] The repair procedure also includes a step 2002 of removing material from the side surface 4 of the cylinder body 1. Specifically, the removal procedure includes at least the step of emitting a laser beam toward the side surface 4 of the cylinder body 1 through the laser emitters 600, 600″ and removing material from the surface until the difference between the detected surface contour DSP and the target surface contour TSP falls within a predetermined tolerance.

[0325] The removal procedure is carried out according to a comparison between the detected surface contour DSP and the target surface contour TSP, i.e. according to the difference parameter DP. The removal procedure thus seeks to remove the material to be removed which is interposed between the target surface contour and the detected surface contour. It is noted that the detected surface contour is a wear contour which exhibits substantially random variations. The difference parameter DP may therefore vary as a function of the angular position of the cylinder body and / or the position of the contour detector. In other words, the portion of material to be removed changes as the position identified on the side surface 4 of the cylinder body 1 changes.

[0326] The control unit is then configured to adjust at least one control parameter of the laser beam emitted by the laser emitter 600,600″ during the removal procedure depending on the contour difference parameter. The control parameters may include average laser beam power, peak laser beam power, duration of the laser beam pulses, duration of the interval between the laser beam pulses, laser beam size, distance between the 600,600″ laser emitter and the outer surface of the cylinder body 1.

[0327] For example, when the value of the differential parameter increases, the control unit can be configured to increase one or more of the peak power of the laser beam, the average power of the laser beam, or the exposure time of the portion of the side surface 4 to the laser beam. Furthermore, when the value of the differential parameter increases, the control unit can be configured to decrease at least one of the angular velocity of the cylinder body 1, the displacement speed of the laser emitters 600,600″ along the main direction Z, and the pulse duration of the laser beam.

[0328] Conversely, when the value of the differential parameter decreases, the control unit can be configured to decrease at least one of the exposure duration, the peak power of the laser beam, and the average power of the laser beam.

[0329] Furthermore, when the value of the difference parameter decreases, the control unit can be configured to increase at least one of the angular velocity of the cylinder body 1, the displacement velocity along the main direction Z of the laser emitters 600, 600″, and the duration of the laser beam pulse.

[0330] Further, the laser beam control parameters may include the displacement speed of the laser emitter 600, 600" along the main direction Z when emitting the laser beam towards the outer surface of the cylinder body 1, the angular velocity of the cylinder body 1 around the rotation axis K when emitting the laser beam towards the outer surface of the cylinder body 1, the number of passes the laser beam makes incident on the same part of the side surface 4 of the cylinder body 1. Further, the laser beam control parameters may include the exposure duration during which the laser beam makes incident on the same part of the side surface 4 of the cylinder body 1. It is noted that the exposure duration depends on the angular velocity of the cylinder body 1 and the displacement speed of the laser emitter 600, 600".

[0331] The laser beam control parameters may also include an energy parameter that represents the energy emitted by the laser beam at the same portion of the side surface 4 of the cylinder body 1. The energy parameter may depend on at least two combinations in the group between the control parameters of the laser emitter 600,600″, the displacement speed of the laser emitter 600,600″ along the main axis Z, the angular velocity of the cylinder body 1 about its rotation axis K, the exposure duration, or the number of passes of the laser beam at the same portion of the side surface 4 of the cylinder body. For example, the energy parameter can be calculated as a function of the peak power of the laser beam pulses, the exposure duration, and the frequency of the laser beam pulses. Alternatively, the energy parameter may be calculated as a function of the average power and the exposure duration of the surface to the laser beam.

[0332] The laser beam emitted towards the side surface 4 of the cylinder body is then configured to locally remove the metallic material from the cylinder body 1. To determine the removal of the material and, conversely, to avoid melting the material itself, the control unit 15 is configured to emit a pulsed laser beam during the removal procedure. These pulses may have a duration between 100 fs and 1000 ns or between 1 fs and 1000 μs and / or a peak power between 1 kW and 10 MW, in particular between 10 kW and 2 MW. The average laser beam power for material removal is between 5 W and 500 W, in particular between 10 W and 200 W.

[0333] To determine material removal, the control unit is configured to emit a pulsed laser beam having a peak power greater than the individual average power, specifically greater than 10, 100 or 1000 times the individual average power.

[0334] A laser beam with these properties makes it possible to remove material from the cylinder body 1, producing a powder of metallic material, in particular steel. The removal of material by laser thus consists of sublimation of the material incident on the laser beam, which, after leaving the surface of the cylinder in its gas phase, recondenses and solidifies after a few seconds, producing a dust of metallic material. The suction system 20 is therefore configured to suck up the metallic dust, in order to reduce the risk to human health.

[0335] The recovery procedure includes repeatedly performing the detection procedure and the removal procedure in a loop to define a closed-loop control system. Specifically, the loop defines an incremental number of laser beam passes. This allows the control unit to verify the surface condition after each pass of the laser beam or after a predefined number of laser beam passes. Once the actual surface condition is verified and the differential parameters are updated, the control unit can again control the laser emitter according to the updated differential parameters. For example, if the updated differential parameters differ from the previously determined differential parameters, the control unit can be configured to modify one or more laser beam control parameters.

[0336] According to one embodiment, the steps of the repair procedure of the cylinder body are listed below.

[0337] The control unit is configured to operate as follows during the removal procedure. · Instruct the motor of the workstation to rotate the cylinder body 1 around its rotation axis K. · Move the laser emitter along the main axis Z. · Emit a laser beam through the laser emitter in the direction of the work area to remove the metal material from the side surface 4 of the cylinder body 1.

[0338] The steps of rotating the cylinder body 1 and moving the laser emitter are performed with complete coverage of the surface contour of the cylinder body 1. During the removal procedure, the steps of rotating the cylinder body around its rotation axis K and moving the laser emitter along the main axis Z can be performed continuously. That is, the step of moving the laser emitter can be after, before, or simultaneous with the step of rotating the cylinder body 1, that is, the step of moving the laser emitter along the main axis Z is partially or entirely simultaneous with the step of rotating the cylinder body 1.

[0339] The removal procedure performs at least one first pass and one second pass path (optionally "n" passes (2 < n < 20)) of the laser beam on one or more target portions of the side surface 4 of the cylinder body 1, removing a predetermined amount of material during each pass. Then, the control unit performs a first pass on the target portion of the surface of the cylinder body using the laser beam, detects the updated contour of the cylinder body 1 in the target portion, compares the updated contour with the TSP target surface contour, and modulates the laser beam emitted by the laser emitters 600, 600” according to the comparison between the updated contour and the TSP target surface contour, so as to perform a second pass using the laser beam. By this procedure, it is possible to update the difference parameter and modulate the laser beam according to the updated difference parameter.

[0340] The removal procedure can include a roughing procedure (Figs. 6a - 6g) and a semi - finishing procedure (Figs. 6h - 6l). Specifically, the control unit is configured to define a roughing procedure including at least one of the following during the removal procedure. · Instruct the laser emitters (600, 600”) to generate a pulsed laser beam. Each of the pulses has an initial duration on the order of magnitudes particularly between 1 ns and 1000 ns. · Optionally, instruct the laser emitters (600, 600”) to generate a laser beam having a size of less than 50 μm, specifically less than 20 μm. The size is the beam diameter.

[0341] The control unit is also configured to define a semi - finishing procedure including the step of instructing the laser emitters 600, 600” to generate a pulsed laser beam during the removal procedure, and each of the pulses has a second duration shorter than the first duration.

[0342] In particular, the second duration is at least 10 times, 100 times or 1000 times smaller than the first duration. For example, the second duration may be on the order between 1 fs (femtosecond) and 1000 ps (picosecond), preferably less than 10 ps.

[0343] The semi - finishing procedure may also include instructing the 600, 600” laser emitters to generate a laser beam having a size of less than 50 μm, particularly less than 20 μm, and the size is the beam diameter.

[0344] The roughing procedure is configured to define a first surface roughness on the side surface 4 of the cylinder body 1, while the semi - finishing procedure is configured to define a second surface roughness on the side surface 4 of the cylinder body 1. That is, the first surface roughness is greater than the second surface roughness, and in particular, the first surface roughness may be “n” times (1.1 < n < 5) greater than the second surface roughness.

[0345] The average power of the laser emitter (600,600") during the rough machining procedure may be essentially the same as the average power of the 600,600" laser emitter during the semi-finishing procedure. The average power may be in the range 0.5W to 500W, in particular in the range 1W to 200W.

[0346] ##Gazette p70 The peak power of the laser beam emitted by the 600,600" laser emitter during the rough machining procedure may be lower than the peak power of the laser beam emitted by the 600,600" laser emitter during the semi-finishing procedure. Furthermore, the peak power of the laser beam in the rough machining procedure may be 10, 100 or 1000 times lower than the peak power of the laser beam in the semi-finishing procedure. The peak power of the laser beam in the rough machining procedure may be between 10 kW and 100 KW and the peak power of the laser beam in the semi-finishing procedure may be between 10 kW and 10 MW.

[0347] For example, the first average surface roughness (Ra) may be between 0.8 μm and 2.0 μm, and the second average surface roughness may be between 0.2 μm and 0.8 μm.

[0348] The removal procedure may further include a finishing procedure following the rough machining procedure and the semi-finishing procedure, which includes at least one of the steps of instructing the laser emitter 600, 600″ to generate a laser beam of continuous type or pulses having a long duration. In particular, the duration of the laser beam pulses in the finishing procedure is longer than the duration of the laser beam pulses emitted in the rough machining procedure and / or the semi-finishing procedure.

[0349] Furthermore, in the finishing procedure the individual peak powers of the laser beams are smaller than the peak powers of the laser beams emitted during the rough machining and / or semi-finishing procedures, in particular the peak powers of the laser beams in the finishing procedure are 10, 100 or 1000 times smaller than the peak powers of the laser beams emitted in the rough machining and semi-finishing procedures. The control unit may also be configured to instruct the laser emitters 600, 600″ in the finishing procedure to generate laser beams having a size, e.g. a diameter, larger than the individual sizes of the laser beams emitted during the rough machining and / or semi-finishing procedures.

[0350] The finishing step is configured to define a finished surface roughness on the side surface 4 of the cylinder body 1 that is smaller than the surface roughness defined during the roughing or semi-finishing step. The average surface roughness (Ra) obtained by the finishing step is less than 0.5 μm, in particular less than 0.4 μm.

[0351] Below is a table showing preferred values ​​of laser beam control parameters associated with side cleaning operations, roughing procedures, semi-finishing procedures, and finishing procedures. These values ​​are not intended to be limiting, but rather to provide an order of magnitude of average, typical, or preferred values ​​of laser beam control parameters for various applications.

[0352] [Table 1]

[0353] In an embodiment generally illustrated by the flow charts of FIGS. 13 and 14, the removal procedure 2002 may include the following operations. · Moving at least one between the cylinder body 1 and the laser emitter 600, 600″ (2002a). · Commanding at least one laser emitter 600, 600″ to emit a pulsed laser beam, the laser pulses removing material from the cylinder body 1 (2002b).

[0354] The step 2002a of moving at least one between the cylinder body 1 and the 600,600″ laser emitter preferably includes rotating the cylinder body 1 about its rotation axis K.

[0355] The step 2002a of moving at least one between the cylinder body 1 and the laser emitter 600, 600" may further comprise a step of controlling the vibration system to determine the vibration of the laser beam. As in the embodiment of FIG. 12b, the vibration of the laser beam and the rotation of the cylinder body may be simultaneous steps with each other.

[0356] Step 2002a of moving the cylinder body 1 and / or 600,600″ laser emitter and step 2002b of emitting a pulsed laser beam are essentially simultaneous with each other. In other words, while the cylinder body is rotating, the laser emitter emits laser pulses at the side of the cylinder body.

[0357] The laser beam pulses are arranged with a time lag relative to one another to define a laser pulse frequency of 10 kHz to 10,000 kHz.

[0358] Each pulse directed at the side surface 4 of the cylinder body 1 defines an individual laser footprint 40 on the side surface 4 of the cylinder body 1, as shown in Figs. 10-12 and 12b. The laser footprint may have a shape within the group between circular, elongated circular, elliptical, and curved with a convex profile. The shape of the laser footprint may vary as a function of the duration of the laser beam pulse that defines the laser footprint, the rotation speed of the cylinder body about the axis of rotation K during the emission of the laser pulse, or the relative speed between the laser beam and the surface of the cylinder body. The laser footprint may be 70 μm in diameter. 2 ~20000μm 2 The surface area may range between .

[0359] It will be noted that each laser pulse 10 results in the formation of a crater on the side surface 4 of the cylinder body 1. Such craters may have a shape and / or surface area substantially equal to the shape and / or surface area of ​​the laser footprint. If desired, the craters may have a surface area slightly smaller than the surface area of ​​the laser footprint. Each crater may have a depth in the range of 1 μm to 20 μm.

[0360] Similarly, the overlapping portion 41 created by the partial overlap of the first and second laser pulses also results in the formation of craters on the side surface 4 of the cylinder body 1. Such craters may have a depth in the range of 10 μm to 100 μm.

[0361] During the removal procedure 2002, the laser pulses define (2002c) laser footprints that at least partially overlap one another by forming respective overlaps between said laser footprints. It will be noted that the step 2002c of defining laser footprints that at least partially overlap one another may be combined with the step 2001 of detecting the surface contour of the cylinder body, as described above. Such an embodiment is shown diagrammatically in the flow chart of FIG. 14.

[0362] Alternatively, according to a further embodiment, the repair procedure 2000 may include a removal procedure 2002 including a step 2002c of defining laser footprints at least partially overlapping each other, without necessarily including a step 2001 of detecting the surface contour of the cylinder body. This embodiment is shown diagrammatically in the flow chart of FIG.

[0363] Each overlapping portion may extend over a surface area between 10% and 95%, optionally between 25% and 75% of the surface area of ​​the laser footprint. Optionally, the overlapping portions may extend over a surface area substantially equal to 50% of the surface area of ​​the laser footprint.

[0364] The inventive method for surface restoration of a cylinder body is a method for grinding the side surface 4 of said cylinder body 1. Specifically, this grinding method removes a surface layer from the rolling cylinder having a thickness between 10 μm and 100 μm, measured along the radial direction of the cylinder body.

[0365] The sides 4 of these rolling cylinders are made of metallic materials, such as materials including steel and cast iron.

[0366] It will also be noted that the above-mentioned methods and those outlined by the flow charts shown in figures 8, 13 and 14 can be performed by the previously described device 10. In particular, the repair procedure 2000 and then the removal procedure 2002 are controlled by the control unit 15 of the device. More particularly, according to the embodiment of figure 14, the control unit 15 of the device performs the detection procedure 2001 and the removal procedure, the latter comprising a step 2002a of moving the cylinder body and / or the laser emitter, a step 2002b of emitting a laser beam towards the side surface 4 of the cylinder body and a step 2002c of defining an overlap 41 between the laser footprints 40.

Claims

1. An apparatus (10) for surface treatment of a cylinder body (1), in particular for surface repair of a rolling cylinder, comprising: - A workstation (100) defining at least one operating position configured to receive a cylinder body (1) having a side surface (4) in the apparatus operating state (10), the workstation (100) being configured to rotationally support the cylinder body (1) according to a predetermined rotation axis (K); - At least one laser emitter (600, 600”) cooperating with the workstation (100) and configured to emit at least one laser beam in the direction of the operating location, the at least one laser emitter (600, 600”) being movable at least along a main axis (Z) substantially parallel to the rotation axis (K) of the cylinder body (1); - At least one profile detector (700) movable at least along a detection axis (Y) substantially parallel to the rotation axis (K) of the cylinder body (1), the at least one profile detector (700) being configured to detect the detected surface profile of the side surface (4) of the cylinder body (1) in the apparatus use state; - A control unit (15) operably connected to the laser emitter (600, 600”) and the at least one profile detector (700), the control unit (15) being configured to execute at least one repair procedure for the side surface (4) of the cylinder body (1) during the apparatus use state, the apparatus further comprising the control unit (15). The repair procedure includes a detection procedure and a removal procedure. The detection procedure includes at least the steps of detecting the detected surface profile (DSP) of the cylinder body (1) using the profile detector (700) and comparing the detected surface profile (DSP) with the target surface profile (TSP) of the cylinder body (1). The removal procedure is executed according to the comparison and includes at least the step of emitting a laser beam through the laser emitter (600, 600”) towards the side surface (4) of the cylinder body (1) to obtain the target surface profile (TSP), the laser beam being configured to locally remove metal material from the cylinder body (1).

2. The detected surface profile (DSP) and the target surface profile (TSP) of the cylinder body (1) are - The angular position of the cylinder body (1), and ・At least one variable geometric feature that depends on at least one of the linear position along the detection axis (Y), including at least one variable geometric feature that depends on at least one of the following: The at least one geometric feature of the detected surface profile (DSP) includes at least one individual height parameter representing the diameter of the cylinder body (1), and / or the variation of the diameter of the cylinder body (1), and / or the intervening distance, particularly the orthogonal distance, between the side surface (4) of the cylinder body (1) and the profile detector (700); The at least one geometric feature of the target surface profile (TSP) includes at least one individual target height parameter representing the diameter of the cylinder body (1), and / or the variation of the diameter of the cylinder body (1), and / or the intervening distance, particularly the orthogonal distance in the operating state and subsequent removal procedures, between the side surface (4) of the cylinder body (1) and the profile detector (700); The control unit is also configured to operate as follows, the device according to claim 1. ・Moving the profile detector (700) along the detection axis (Y). ・During the movement of the profile detector (700) along the detection axis (Y), detecting at least one geometric feature of the surface profile (DSP) by the profile detector (700). ・Associating the at least one geometric feature of the detected surface profile (DSP) of the cylinder body (1) with the individual linear positions along the detection axis (Y). And, if necessary, ・Rotating and moving the cylinder body (1) around the rotation axis (K), particularly using an electric motor operably connected to the cylinder body. ・During the rotation of the cylinder body, detecting the surface profile (DSP) using the profile detector (700). ・Associating the at least one geometric feature of the detected surface profile (DSP) of the cylinder body (1) with the individual angular positions of the cylinder body (1).

3. The control unit (15) is configured to command the laser emitters (600, 600”) to emit a pulsed laser beam during the removal procedure, The pulsed laser beam is configured to remove material from the cylinder body (1), and the material is metal. The control unit is configured to emit a pulsed laser beam having a peak power greater than the relative average power. Specifically, the peak power is 10 times, 100 times, or 1000 times greater than the relative average power. The impulse, as necessary, is the device according to claim 1, having the following: - A duration of 100 fs to 1000 ns, or 1 fs to 1000 μs, and / or - A peak power of 1 kW to 10 MW, specifically 10 kW to 2 MW.

4. The comparison between the detected surface profile (DSP) and the target surface profile (TSP) defines the differential profile parameters of the cylinder body (1), The differential profile parameters represent the difference or ratio between the detected surface profile (DSP) and the target surface profile (TSP), The control unit is configured to adjust at least one device operation parameter within a group including the following according to the differential profile parameters during the removal procedure, - At least one control parameter of the laser beam emitted by the laser emitter (600, 600"), in particular, the control parameter is the average power of the laser beam, the peak power of the laser beam, the duration of the pulse of the laser beam, the duration of the interval between pulses of the laser beam, the size of the laser beam, the distance between the laser emitter (600, 600") and the outer surface (1) of the cylinder body. - The displacement speed of the laser emitter (600, 600") along the main direction (Z) during the emission of the laser beam towards the outer surface of the cylinder body (1). - The angular velocity of the cylinder body (1) around its rotation axis (K) during the emission of the laser beam towards the outer surface of the cylinder body (1). - The number of passes through which the laser beam is incident on the same part of the side surface (4) of the cylinder body (1). - The exposure time when the laser beam is incident on the same part of the side surface (4) of the cylinder body (1), specifically, the time depends on the angular velocity of the cylinder body (1) and the displacement speed of the laser emitter (600, 600"). - An energy parameter representing the energy radiated by the laser beam on the same part of the side surface (4) of the cylinder body (1). In particular, the energy parameter depends on at least two combinations within the following group. o The at least one laser emitter control parameter (600, 600"). o The displacement speed of the laser emitter (600, 600") along the main axis (Z). o The angular velocity of the cylinder body (1) around its rotation axis (K). o The exposure time o The number of passes. Furthermore, the control unit is configured as follows, the device according to claim 1. ・ As the value of the differential parameter increases, o increase at least one of the average power, the peak power of the laser beam, the exposure time, and the number of passes of the laser beam incident on the same part of the side surface (4), particularly increase the peak power of the laser beam, and / or o decrease at least one of the angular velocity of the cylinder body (1) and the displacement velocity of the laser emitters (600, 600") along the main direction (Z), ・ As the value of the differential parameter decreases, o decrease at least one of the average power, the peak power of the laser beam, the exposure time, and the number of passes of the laser beam incident on the same part of the side surface (4), particularly decrease the peak power of the laser beam, and / or o increase at least one of the angular velocity of the cylinder body (1) and the displacement velocity of the laser emitters (600, 600") along the main direction (Z), Optionally, the differential parameter is proportional to the amount of material to be removed intervening between the detected surface profile (DSP) and the target surface profile (TSP).

5. The removal procedure is ・ setting predetermined laser emitter control parameters, ・ optionally setting the angular velocity of the cylinder body (1) around the rotation axis (K) and / or setting the displacement velocity of the profile detector (700) along the detection axis (Y), ・ determining or receiving as input a removal index representing the thickness of the material removed from the side surface (4) of the cylinder body (1) during a single pass of the laser beam, ・ calculating the number of passes of the laser emitter required to obtain the target surface profile (TSP) according to the profile differential parameter and the removal index, where optionally the number of passes is calculated as the ratio of the profile differential parameter to the removal index, and in particular the ratio is approximated to an integer by default, As the peak power of the laser beam pulse increases, the removal index increases and the number of laser passes required to obtain the target surface profile (TSP) decreases accordingly, As the peak power of the laser beam pulse decreases, the removal index decreases and the number of laser passes required to obtain the target surface profile (TSP) increases accordingly, the apparatus according to any one of claims 1 to 4.

6. The step of detecting the outer profile of the cylinder body (1) using the profile detector (700) is - Step of angularly rotating the cylinder body (1) around its rotation axis (K), - Step of moving the contour detector (700) along the detection axis (Y) to at least partially, in particular entirely cover the length of the outer surface of the cylinder body (1), where said length is measured parallel to the rotation axis (K) of the cylinder body (1), including, The control unit is configured to operate as follows during the removal procedure, - Step of rotating the cylinder body (1), - Step of moving the laser emitter along the main axis (Z), - Step of emitting a laser beam through the laser emitter in the direction of the work location to remove metal material from the side surface (4) of the cylinder body (1), The step of rotating the cylinder body (1) and the step of moving the laser emitter are executed in this order, or in the reverse order, or simultaneously, so as to completely cover the surface contour of the cylinder body (1). The device according to any one of claims 1 to 4.

7. The contour detector (700) is, - At least one inner diameter including one or more movable arms, configured to contact the side surface (4) of the cylinder body (1) by the tips of said one or more movable arms, and said movable arms are configured to detect the surface contour of the cylinder body (1), at least one inner diameter (caliber), or - At least one non-contact distance detector configured to measure the intervening distance from the side surface (4) of the cylinder body (1), specifically including at least one of an optical detector, for example, between a laser and a time-of-flight detector. The device according to any one of claims 1 to 4 including a non-contact distance detector.

8. The repair procedure includes repeatedly executing the detection procedure and the removal procedure within a loop defining a closed-loop control system. Optionally, such a loop defines the increasing number of times the laser beam passes through the same part of the cylinder body (1), This removal procedure includes performing at least a first pass and a second pass. Optionally, at one or more target parts of the side surface (4) of the cylinder body (1), the laser beam passes through "n" times (2 ≤ n ≤ 20), and a predetermined amount of material is removed during each pass, The control unit is configured to operate as follows, - Between the first pass and the second pass in terms of time, instruct the contour detector (700) to detect the updated contour of the cylinder body (1) in the target portion. - Compare the updated contour with the target surface profile (TSP). - Modulate the laser beam emitted by the laser emitters (600, 600'') during the second pass according to the comparison between the updated contour and the target surface profile (TSP), and update the individual difference parameters. The modulation step depends on the updated difference parameters. The device according to any one of claims 1 to 4.

9. The device according to any one of claims 1 to 4, wherein the control unit is configured to control at least one of the following operating parameters. - The average power or peak power of the laser emitters (600, 600''). The average power or peak power is adjustable between a minimum power (Pmin) and a maximum power (Pmax). - The laser beam pulse duration. The laser pulse duration is adjustable between a minimum laser pulse duration (Tmin) and a maximum laser pulse duration (Tmax). Optionally, the control unit is configured to adjust both the laser emitter power (600, 600'') and the duration of the laser beam pulse.

10. The control unit is configured to define a roughing procedure including at least one of the following during the removal procedure. - Instruct the laser emitters (600, 600'') to generate a pulsed laser beam, each of the pulses having an initial duration on the order of magnitude, specifically between 1 ns and 1000 ns. - Optionally, instruct the laser emitters (600, 600'') to generate a laser beam having a size of less than 50 μm, specifically less than 20 μm. The size is the beam diameter. The control unit is also configured to define a semi-finishing procedure including at least one of the following steps during the removal procedure. - Instruct the laser emitter (600, 600") to generate a pulsed laser beam, each of the pulses having a second duration shorter than the first duration, in particular the second duration being at least 10 times, 100 times or 1000 times smaller than the first duration, the second duration being in particular on the order of magnitude between 1 fs and 1000 ps, preferably less than 10 ps. - Optionally, instruct the laser emitter (600, 600") to generate a laser beam having a size of less than 50 μm, specifically less than 20 μm, the size being the beam diameter. The roughing procedure is configured to define a first surface roughness on the side surface (4) of the cylinder body (1), and the semi-finishing procedure is configured to define a second surface roughness on the side surface (4) of the cylinder body (1), the first surface roughness being greater than the second surface roughness, and optionally, the first surface roughness being "n" times (1.1 < n < 5) greater than the second surface roughness. Optionally - The average power of the laser emitter (600, 600") during the roughing procedure is substantially the same as the average power of the laser emitter (600, 600") during the semi-finishing procedure, the average power being in the range of 0.5 W to 500 W, and / or - The peak power of the laser beam emitted by the laser emitter (600, 600") during the roughing procedure is lower than the peak power of the laser beam emitted by the laser emitter (600, 600") during the semi-finishing procedure, the peak power of the laser beam during the roughing procedure being 10 times, 100 times or 1000 times lower than the peak power of the laser beam during the semi-finishing procedure. The laser emitter is configured to emit a laser beam having a wavelength between 0.3 μm and 1 μm during the roughing procedure and / or the semi-finishing procedure, the device according to any one of claims 1 to 4.

11. The control unit is configured to define a finishing procedure including the following during the removal procedure. - Instruct the laser emitter (600, 600") to generate a laser beam of the following type. o Continuous type, or o A type comprising pulses having the following. ■ An individual duration longer than the duration of the laser beam pulses emitted during the roughing procedure and the semi-finishing procedure. In particular, the duration of the pulse during the finishing procedure is on the order of magnitude between 1 μs and 1000 ms, and / or ■ An individual peak power that is smaller than the peak power of the laser beam emitted in the roughing procedure and the semi-finishing procedure. In particular, the peak power of the laser beam in the finishing procedure is 10 times, 100 times or 1000 times smaller than the power peak of the laser beam irradiated in the roughing procedure and the semi-finishing procedure. ・If necessary, command the laser emitter (600, 600”) to generate a laser beam having a size larger than 100 μm, particularly larger than 200 μm. Specifically, the size is between 100 μm and 500 μm. The finishing procedure is configured to define a finishing surface roughness of less than 0.5 μm, specifically less than 0.4 μm, specifically between 0.05 μm and 0.4 μm on the side surface (4) of the cylinder body (1), according to any one of claims 1 to 10.

12. The apparatus includes a gas nozzle (610) configured to deliver a gas flow in the direction of a part of the side surface (4) of the cylinder body (1) affected by the laser beam. If necessary, the side surface portion (4) is the working portion of the side surface (4) of the cylinder body (1). The gas nozzle (610) is configured to deliver at least one of the following: ・A non-oxidizing gas, particularly an inert gas. In particular, the non-oxidizing gas includes at least one in the group including nitrogen, helium and argon. ・A reactive gas configured to interact with the side surface (4) of the cylinder body (1) to cause a chemical change in the part of the side surface (4) of the cylinder body (1) affected by the laser beam. The reactive gas includes at least one of oxygen or air. The apparatus includes a shield cover (1000) that defines an internal space accommodating at least a work station and a laser emitter, and if necessary, a contour detector (700). The shield cover (1000) is configured to confine the laser beam within the internal space to prevent the laser beam from escaping. The internal space of the shield cover (1000) is substantially communicating with the external environment only through a filter device configured to prevent leakage of metal dust generated by the removal procedure from the internal space to the surrounding environment, according to any one of claims 1 to 4.

13. The device includes first and second laser beam sources (601, 601"), each connected to the laser emitter (600) by an individual cable, specifically an optical fiber cable, namely the cable of the first laser beam source and the cable of the second laser beam source that flows into the same laser emitter (600). The first laser beam source (601) is configured to generate a first laser beam, and the second laser beam source (601") is configured to generate a second laser beam. The first laser beam includes at least one control parameter, specifically the peak power or duration of a laser pulse, or a wavelength different from that of the second laser beam. The control unit is configured to selectively drive the first or second laser beam source (601, 601") to emit individual laser beams to the laser emitter. Or The device includes the laser emitter (600) and the auxiliary laser emitter (600") that are distinguished from each other and installed at different positions within the workstation. The device further includes a first laser beam source (601) connected to the laser emitter (600) by o individual first cables, specifically optical fiber cables, a second laser beam source (601") connected to the auxiliary laser emitter by o individual second cables, specifically optical fiber cables. The first laser beam source (601) is configured to generate a first laser beam, and the second laser beam source (601") is configured to generate a second laser beam. The laser emitter (600) is configured to emit a first laser beam along a first emission direction, while the auxiliary laser emitter (600") is configured to emit a second laser beam along a second emission direction. The first emission direction and the second emission direction intersect various regions of the operating location. Or, during the operating state, they intersect various parts of the side surface (4) of the cylinder body (1). The control unit is configured to drive the first and second laser beam sources (601, 601") simultaneously or selectively to emit individual laser beams. If necessary, o The first laser beam includes at least one control parameter or wavelength different from that of the second laser beam, and the control unit is configured to drive the first and second laser beam sources simultaneously or selectively to emit individual laser beams. Or, o The first laser beam and the second laser beam have the same wavelength, and the control unit is configured to drive the first and second laser beam sources simultaneously or selectively to emit individual laser beams. The device according to any one of claims 1 to 4.

14. The control unit (15) is configured to command at least one laser emitter (600, 600”) to emit a pulsed laser beam suitable for removing material from the cylinder body (1) during the removal procedure (2002). The removal procedure (2002) includes: ・ A step (2002a) of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”), and arranging the cylinder body (1) to rotate around its rotation axis (K) as necessary. ・ A step (2002b) of commanding at least one laser emitter (600, 600”) to emit the pulsed laser beam, and the pulse is capable of removing material from the cylinder body (1). The laser beam pulses are arranged to be temporally offset from each other. Each pulse directed at the side surface (4) of the cylinder body (1) is configured to define individual laser footprints (40) on the side surface (4) of the cylinder body (1) during the operating state of the device. The laser pulses define at least partially overlapping laser footprints by forming individual overlapping portions (41) between the laser footprints. The step of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”), and the step (2002b) of commanding at least one laser emitter (600, 600”) to emit a pulsed laser beam are substantially simultaneous with each other. The device according to any one of claims 1 to 4.

15. A device (10) for surface treatment of a cylinder body (1), particularly for surface repair of a rolling cylinder, - A workstation (100) that defines at least one operating location configured to receive a cylinder body (1) having a side surface (4) in the device operating state (10), the workstation (100) being configured to rotatably support the cylinder body (1) according to a predetermined rotation axis (K). - At least one laser emitter (600, 600") that cooperates with the workstation (100) and is configured to emit at least one pulsed laser beam in the direction of the operating location, the laser emitter (600, 600") being movable at least along a main axis (Z) substantially parallel to the rotation axis (K) of the cylinder body (1). - A control unit (15) operably connected to the laser emitter (600, 600") and configured to execute at least one repair procedure on the side surface (4) of the cylinder body (1) during the operating state of the device (1). The repair procedure (2000) includes a removal procedure (2002) including at least the following steps. o A step (2002a) of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600"). o A step (2002b) of instructing the at least one laser emitter (600, 600") to emit the pulsed laser beam, the pulse being capable of removing material from the cylinder body (1). The laser beam pulses are arranged with a temporal shift relative to each other. Each pulse directed at the side surface (4) of the cylinder body (1) is configured to define an individual laser footprint (40) on the side surface of the cylinder body (1) during the operating conditions of the device. The laser pulses define laser footprints that at least partially overlap each other, forming individual overlapping portions (41) between the laser footprints, the device.

16. The overlapping portion (41) extends over a surface area between 10% and 90% of the surface area of the laser footprint (40), and optionally between 25% and 75% as required. The laser beam pulses are arranged with a temporal shift relative to each other, defining a pulse frequency between 10 kHz and 10000 kHz as required, more specifically between 10 kHz and 1500 kHz. The laser footprint (40) defines a material removal area and its boundary from the cylinder body (1), and the apparatus according to claim 15.

17. The step of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”) includes the step of arranging the cylinder body (1) in a rotating state around its rotation axis (K), Furthermore, the overlapping portion is defined by at least a partial overlap of laser footprints that are continuous with each other, in particular directly continuous with each other, The step (2002a) of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”), and the step (2002b) of instructing the at least one laser emitter (600, 600”) to emit a pulsed laser beam are substantially simultaneous with each other, and / or, The overlapping portion is defined by an overlap between a first laser print and a second laser print that is directly temporally continuous with the first laser print, The second laser footprint is defined using a time delay from the first laser footprint equal to the reciprocal of the pulse frequency, and the apparatus according to claim 16.

18. The control unit (15) is configured during the removal procedure to, - command the rotation of the cylinder body (1) around the rotation axis (K) at a predetermined speed, - command at least one laser emitter (600, 600”) to emit a first laser pulse to define the first laser imprint on the cylinder body, - command at least one laser emitter (600, 600”) to emit a second laser pulse to define the second laser imprint on the cylinder body, The second laser imprint partially overlaps the first laser imprint, The second laser pulse is directly temporally continuous with the first laser pulse, Optionally, the second laser pulse is emitted with a time delay equal to the reciprocal of the laser pulse frequency with respect to the first laser pulse, Furthermore, the control unit (15) is configured during the removal procedure to, - Instruct at least one laser emitter (600, 600") to emit a third laser pulse temporally following the first laser pulse and the second laser pulse, so as to define a third laser imprint on the cylinder body that partially overlaps the second laser imprint, is outside the first laser imprint, or is in contact with the first laser imprint. Or, - Instruct at least one laser emitter (600, 600") to emit a third laser pulse temporally following the first laser pulse and the second laser pulse, and is configured to define a third laser imprint on the cylinder body that partially overlaps the second laser imprint and the first laser imprint. The third laser pulse is temporally directly continuous with the second laser pulse. Optionally, the third laser pulse is emitted using a time delay from the second laser pulse equal to the reciprocal of the pulse frequency, for the apparatus according to claim 17. **Claim 19** The apparatus comprises a vibration system configured to determine the spatial vibration of the direction of the laser beam emitted by at least one laser emitter (600, 600") at a certain vibration frequency. The vibration frequency is between 10 Hz and 20000 Hz, more specifically between 100 Hz and 10000 Hz, more specifically between 200 Hz and 5000 Hz, more specifically between 200 Hz and 2000 Hz. Optionally, the laser beam is a pulsed laser beam. Optionally, the spatial vibration defines the vibration amplitude of the laser beam on the side surface (4) of the cylinder body (1) between 0.05 mm and 5 mm, specifically between 0.1 mm and 2 mm, if necessary. The control unit (15) is configured to drive the vibration system to determine the spatial vibration of the laser beam direction during the removal procedure (2002), for the apparatus according to any one of claims 1 - 4, 15 - 18. **Claim 20** The removal procedure (2002) includes performing the following steps substantially simultaneously with each other. - A step of moving the cylinder body (1) in a rotating state. - A step of determining the spatial vibration of the laser beam direction by the vibration system. - A step of instructing at least one laser emitter (600, 600") to emit a laser pulse. The control unit (15) is configured to determine the oscillation frequency of the oscillation system as a function of the rotational speed of the cylinder body, or vice versa, The device includes a rotational speed detector configured to detect the rotational speed of the cylinder body (1). The control unit (15) - determines the oscillation frequency of the oscillation system as a function of the rotational speed of the cylinder body detected by the speed detector, or - is configured to determine the rotational speed of the cylinder body as a function of the oscillation frequency of the oscillation system, Furthermore, the control unit (15) - increases the oscillation frequency of the oscillation system as the rotational speed of the cylinder body increases, and - is configured to decrease the oscillation frequency of the oscillation system as the rotational speed of the cylinder body decreases, according to any one of claims 1 to 19.

21. The spatial oscillation of the laser beam direction determined by the oscillation system defines the movement of the laser beam along a predetermined trajectory, and the predetermined trajectory includes at least one of the following: - Circular trajectory - Straight trajectory - Curved trajectory - Elliptical trajectory The oscillation system is configured to move the laser beam along an oscillation direction substantially parallel to the rotation axis (K) of the cylinder body (1). In particular, on the side surface (4) of the cylinder body (1), the oscillation amplitude of the laser beam is defined substantially parallel to the rotation axis (K) of the cylinder body (1). The device according to claim 19.

22. To obtain an overlapping portion (41) between the laser footprints, the control unit (15) is configured to determine the oscillation frequency of the oscillation system as a function of at least one of the following: - One-dimensional representative parameter (D) of the laser footprint (40) ・Frequency of the laser pulse (f ｐｕｌｓｅ ) - Oscillation amplitude (L) of the laser pulse on the side surface (4) of the cylinder body (1) The control unit (15) - decreases the oscillation frequency as the representative parameter (D) of the size of the laser footprint (40) decreases, - Optionally, is configured to increase the oscillation frequency as the representative parameter (D) of the size of the laser footprint (40) increases, The control unit (15) is configured to determine the oscillation frequency of the oscillation system according to the following formula to obtain the overlapping portion (41). The device according to claim 19. 【Number 1】 ・f ｏｓｃ is the vibration frequency of the laser beam that can be determined by the vibration system, and specifically, the vibration frequency is expressed in Hz. - D is a representative parameter of the size of the laser footprint (40), and the representative parameter D is specifically, for example, a linear dimension expressed in mm. If necessary, the representative parameter D is the diameter of the laser footprint (40). ・ T is the time interval between two laser pulses. Specifically, the time interval is the reciprocal of the pulse frequency f of the laser beam ｏｓｃ and, for example, the time interval is expressed in seconds. - L is the vibration amplitude of the laser beam on the side surface (4) of the cylinder body (1), and the vibration amplitude of the laser beam is specifically expressed in mm. In particular, the vibration amplitude L is between 0.05 mm and 5 mm, and more specifically, between 0.1 mm and 2 mm.

23. At least one laser emitter (600, 600”) is configured to direct a laser beam to a focus, The focus defines the minimum spatial dimension of the laser beam. In particular, the rays defining the laser beam converge at the focus, At least one laser emitter (600, 600”) is configured to define the focus at a blur distance (Δf) from a predetermined reference plane by the side surface (4) of the cylinder body (1) during the operation state of the device, In particular, the blur distance (Δf) is a non-zero value and is between 0.01 mm and 2 mm in absolute value, and more specifically between 0.1 mm and 0.5 mm, Furthermore, at least one laser emitter (600, 600”) is configured to vary the blur distance (Δf) within the following range, for the device according to claims 1-4, 15-18. - When the focus is outside the cylinder body, a positive value of the blur distance (Δf). - When the focus is inside the cylinder body, a negative value of the blur distance (Δf).

24. The frequency of the laser pulse is greater than the rotational frequency of the cylinder body (1). If necessary, the rotational frequency of the cylinder body is defined as the number of complete rotations per second of the cylinder body (1) around the rotation axis (K), The frequency of the laser pulse is at least “n” times greater than the rotational frequency of the cylinder body (1), where n > 100, in particular n > 500, more specifically n > 1000, and even more specifically n > 3600, The rotational frequency of the cylinder body (1) is between 5 RPM and 250 RPM, and if necessary, between 20 RPM and 100 RPM, for the device according to any of claims 15-18.

25. The control unit (15) calculates and commands the frequency of the laser beam pulse according to the desired surface area of the overlapping part, - ・configured to calculate and command the rotational speed or rotational frequency of the cylinder body (1), and / or The control unit (15) is configured to operate as follows during the removal procedure (2002), the apparatus according to any one of claims 15 to 18. ・receiving or calculating the desired surface area of the overlapping portion as an input. ・calculating the pulse frequency of the laser beam and the rotational speed or rotational frequency of the cylinder body (1) according to the desired surface area of the overlapping portion (41). ・executing a repair procedure (2000), particularly a removal procedure (2002), by setting the laser beam pulse frequency and the rotational speed of the cylinder body.

26. A method for surface repair of a cylinder body (1), optionally using the apparatus according to any one of claims 1 to 25, wherein the cylinder body (1) is movable by rotation about a rotation axis (K) and includes a side surface (4) extending in the longitudinal direction between a first end and a second end of the cylinder body (1), the method includes at least one repair procedure (2000) for the side surface (4) of the cylinder body (1), and the repair procedure (2000) includes o a detection procedure (2001) including at least the following steps, ■ detecting the surface profile (DSP) of the side surface (4) of the cylinder body (1) using a contour detector (700). ■ comparing the detected surface profile with the target surface profile (TSP) of the cylinder body (1) (step 1). o a removal procedure (2002) including the following steps, executed according to the comparison, ■ emitting a laser beam toward the side surface (4) of the cylinder body (1) through a laser emitter (600, 600”), to achieve the target surface profile (TSP), wherein the laser beam locally removes metal material from the cylinder body (1). Optionally, the laser emitter is a solid-state laser emitter including at least one of the following groups. ・Disk laser emitter ・Fiber laser emitter ・Nd:YAG laser emitter ・Yb:YAG laser emitter ・Nd:YVO4 laser emitter ・Diode laser emitter ・Titanium sapphire laser emitter

27. The removal procedure (2002) includes the following steps ・Moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”) (2002a), and optionally rotating the cylinder body (1) around its rotation axis (K). ・Instructing the at least one laser emitter (600, 600”) to emit a pulsed laser beam (2002b), the laser pulses removing material from the cylinder body (1). The laser beam pulses are arranged with a temporal shift relative to each other, Each pulse directed towards the side surface (4) of the cylinder body (1) defines an individual laser imprint on the side surface (4) of the cylinder body (1), The pulses define laser footprints (40) that at least partially overlap each other by forming individual overlapping portions (41) between the laser footprints, according to the method of claim 26.

28. A method (1) for surface repair of a cylinder body, comprising the step of performing a procedure (2002) for removing material from the cylinder body, The removal procedure (2002) includes the step of emitting successive laser pulses towards the side surface (4) of the cylinder body (1) (2002b), Each laser pulse defines an individual laser footprint on the side surface (4) of the cylinder body (1) (2002c), The laser pulses define laser footprints (40) that at least partially overlap each other by forming individual overlapping portions (41) between the laser footprints.

29. The method includes at least one repair procedure (2000) for the side surface (4) of the cylinder body (1), The repair procedure (2000) includes the removal procedure (2002) including the following steps, o Moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600”) (2002a). o Instructing the at least one laser emitter (600, 600”) to emit the pulsed laser beam, the pulses being configured to remove material from the cylinder body (1) (2002b). The laser beam pulses are arranged with a temporal shift relative to each other, The method according to any one of claims 26 to 28, wherein the moving step (2002a) of moving at least one between the cylinder body (1) and the at least one laser emitter (600, 600") and the step (2002b) of instructing the at least one laser emitter (600, 600") to emit a pulsed laser beam are substantially simultaneous with each other.

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