FR2853573A1 - Laser cutting installation for sheet metals or other materials has torch positioner with gripper and holder for material and supporting pallet for cut-out sections - Google Patents

Abstract

The installation has a cutting station (300) with a laser torch (304) directing a beam vertically onto a target point on the sheet material (10). It has a mechanism (306, 308, 310) for moving the torch in three perpendicular directions (X, Y, Z) so that the target point can be moved in a series of predetermined closed trajectories defining the shape of the sections to be cut out of the material. It also has a positioner with a holder for the lateral edges of the material, and a supporting pallet (312) to receive each cut-out section. The pallet is able to move synchronously with the laser torch and has hole for the laser beam to pass through, together with cinders from the cutting operation.

Description

Installation for laser cutting sheet material

  The present invention relates to an installation for laser cutting sheet metal from various materials, metallic or otherwise.

  The technique of laser cutting of sheets is a well known technique, which implements an installation where the sheets to be cut are deposited one by one on an appropriate support, after which a laser torch, moved by a mechanism with crossed movements controlled by a computer system ensures cutting of the pieces following predetermined cutting paths corresponding to the outline of these pieces.

  These devices cut individual sheets, for example of the format 1000 x 1000 mm or 1500 x 1000 mm, previously straightened to ensure good flatness, and which are placed manually or by an automatic handling device on the table forming the support. cutting.

  This cutting table typically consists of a spiked mat or the like (for example a honeycomb structure), so as to interfere as little as possible with the cutting operation of the sheet, allowing the passage and collection of the slag from cutting produced during this operation; the sheet simply rests on these pins by its own weight, without being otherwise maintained. The pins are attached at the bottom to a flat support and must have a sufficient height so that the laser beam cannot interact with the support holding these pins and cut this support (the depth or height of action of the beam being limited) .

  A first drawback lies in the fact that this carpet with t T 2853573 spikes is a consumable element, because it is subjected to the action of the laser beam which rapidly degrades the spikes. It is therefore necessary to regularly change this support which, in addition to the cost resulting from the presence of consumable elements, further reduces the production rate of the installation.

  Another drawback is related to the recovery and evacuation of the cut pieces which rest on the 10 pins: it often happens that the cut pieces fall on the cutting table between the pins, and mix with the slag which had been produced during the cutting process. The intervention of an operator is therefore necessary to recover these parts and, when they have fallen among the slag, to clean them because they can then no longer be used as they are.

  To overcome this drawback, it is possible to control the cutting path so that the parts 20 remain fixed to the base plate by one or two bridges of material: this prevents them from falling among the slag but still involves the intervention of an operator, to detach the parts and possibly deburr them at the location of the material bridge.

  On the other hand, when a sheet has been completely cut, there is of course the need to evacuate from the support the sheet drop formed by the uncut material, which also involves the intervention of an operator because very 30 often parts are stuck in the sheet metal drop, which moreover prevents re-stacking of these scraps after cutting.

  One of the aims of the invention is to propose a laser cutting installation which eliminates all of these drawbacks, making it possible to rationalize the cutting process by extensive automation and without operator intervention, if this is not the case. is to adjust the cutting parameters and check the correct operation of the machine.

  Another object of the invention is to propose an installation 5 for laser cutting which can possibly operate continuously, that is to say which can use a sheet in the form of a roll instead of using individual sheets loaded one by one. in the machine and cut discontinuously. Such a continuous operating mode makes it possible to accelerate the production rates while avoiding interruptions and dead times between the cutting phases proper.

  Yet another object of the invention is to propose an installation which can cut out pieces of different shapes from the same sheet and then sort and automatically evacuate these pieces by grouping identical pieces in separate bins.

  Yet another object of the invention is to propose an installation which, after cutting has been carried out, can automatically evacuate and eliminate the falling sheet, always automatically without interrupting the continuous production line and without it being necessary. to call upon an operator for this particular operation.

  To this end, the invention proposes an installation comprising, in a manner known per se, a cutting station with: - a laser torch, comprising means for producing and projecting vertically a laser beam at a target point of the section of material, 35 - means for positioning the section of material under the laser torch, and - a crossed movement mechanism, capable of moving the torch in a controlled manner in a horizontal plane in first and second horizontal directions so as to have the target point describe a series of closed predetermined cutting paths defining the outline of respective pieces to be cut from the material section. A third vertical axis moves along the thickness of the sheet to be cut.

  Characteristically of the invention: the positioning means comprise means for gripping and retaining the section of material by lateral edges thereof, these means being capable of leaving essentially the space situated beneath -face of the material at least over the extent of the cutting paths, and - the cutting station comprises, under the maté20 riau section and not in contact with it, a support pallet having a collection surface of at least a piece after its cutting, this surface being horizontal and its extent sufficient to allow it to collect by gravity and support the cut piece after execution of the cutting path by the laser torch, the support pallet being provided at the right of the target point d an orifice for the passage of the laser beam, also capable of letting the slag generated at the target point 30 escape during the material cutting process.

  According to various advantageous subsidiary characteristics - the support pallet is a mobile pallet, capable of being moved in synchronism with the movement of the torch so as to keep the passage opening permanently positioned in line with the laser beam; - The laser torch and the support pallet are integral in their horizontal movements with a movable assembly moved by the mechanism with crossed movements; - the support pallet is a tilting pallet between a first position, kept for the duration of the cutting process, o the collection surface is horizontal to receive and support the piece (s) cut (s), and a second position , after completion of the cutting process, this collection surface is inclined relative to the horizontal in order to laterally pour said cut piece (s) towards a recovery zone located below the support pallet ; - in the latter case, the cutting station can advantageously include, in the recovery zone, a recovery and collection tray for the cut pieces, this tray being disposed below the tilting support pallet 20 so as to receive the pieces successively cut after completion of the cutting process when the support pallet is tilted to its second position; - This recovery and collection tray is preferably a movable tray in a first horizontal direction to allow the evacuation of the cut pieces after completion of the cutting process; in a particular embodiment, the movable plate is able to be moved in said first horizontal direction in synchronism with the movements of the torch in this same first horizontal direction, the plate being provided with a transverse slot extending along said second horizontal direction and forming a slot for the passage of the laser beam, also capable of letting the slag generated at the target point escape during the process of cutting the material; preferably, the cutting station further comprises, below the support pallet and the recovery tray, a slag collecting tank having passed through the orifice of the support pallet and the slot in the recovery tray; - In an advantageous embodiment, the recovery tray is an opening bottom tray, having a closed position, for the duration of the cutting process, where the tray collects the successively cut pieces, and an open position, after completion of the cutting process, o the collected cut pieces are evacuated to a storage area, - when the installation includes, downstream of the cutting station, a sorting and storage station for the cut pieces, the recovery tray can be a movable tray capable of operating the transfer of the pieces cut into, on the one hand, the cutting station and, on the other hand, a container selectively chosen from a plurality of containers placed at the sorting and storage station; - The installation may further include, downstream of the cutting station 25, a station for eliminating scrap material remaining after cutting the parts.

  The teachings of the invention are particularly applicable to the continuous cutting of a sheet metal strip 30 in the form of a continuous strip. The installation then comprises, upstream of the cutting station, a station for storing and delivering a strip of sheet metal, capable of supplying the cutting station in a controlled manner, and the means for gripping and retaining the cutting station. are means capable of being released during a phase of advancing a length of strip constituting said section of material to be cut, and activated during a subsequent phase of cutting of this section of material.

  In the latter case, there can be provided, upstream of the cutting station, a station for straightening the sheet metal strip delivered by the storage and debit station.

  Other characteristics and advantages of the invention will appear on reading the following description of an exemplary embodiment of the invention, given by way of illustration with reference to the appended figures, in which the same 10 numerical references designate elements. identical or functionally similar.

  In these figures: - Figure 1 is an overview of the cutting installation according to the invention in a continuous operating configuration, showing the different positions of this installation; - Figure 2 shows, more precisely, the cutting station and the sorting and storage station of the installation of Figure 1, just after the cutting phase of one of the parts by the laser torch; - Figure 3 is homologous to Figure 2, in a configuration where a set of identical parts cut by the laser torch has been collected and is then transferred to a corresponding storage bin; - Figure 4 shows schematically, in elevation, the different elements constituting the cutting station of the installation of the invention; and - Figure 5 is a top view, taken along the line 35 V-V of Figure 4, with partial cutaway of the sheet metal tape to show the elements located below it.

  FIG. 1 shows the installation according to the invention, which constitutes a complete production line for continuous laser cutting.

  It will be noted beforehand that the teachings of the invention can also be applied to a cutting line operating in a discontinuous manner, that is to say operating on rectangular sheets successively loaded and then discharged on the cutting station. Such an operating mode 10 is entirely conceivable, although the invention applies in a particularly advantageous manner to continuous operation, as will be understood on reading the

description below.

  The parts that we want to obtain are cut from a strip 10 conditioned in the form of a continuous sheet metal strip, wound to form a coil 12 at a storage and flow station 100 which unrolls the sheet in a step and a programmable speed.

  The sheet is then directed to a straightening station 200 which will ensure its flatness.

  The sheet is then directed towards the cutting station 300, which will be described in more detail with reference to FIGS. 2 to 5.

  The machine is also equipped, downstream of the cutting station, with a sorting and storage station 400 for finished parts, operating in a coordinated manner with the cutting station 300 in the manner which will be explained below.

  The various stations constituting the installation of the invention are controlled by a common control cabinet 500, 35 operating under the control of a microcomputer 600 in which the shapes of the parts are in particular stored, for example from software of CAD / CAM, so as to automatically control the movements of the laser torch of the cutting station 300.

  With reference to FIGS. 2 to 5, a description will now be given in more detail of the various elements constituting the cutting station 5 and the sorting and storage station 400.

  More specifically, the cutting station 300, which receives the sheet 10 unwound and straightened, comprises means for im10 mobilizing the section of sheet metal to be cut, for example a system of pliers 302 (FIGS. 4 and 5) which come to grip the ribbon of sheet by the edge, thus leaving free the two faces, upper and lower, of this sheet 10.

  The installation comprises, in itself known manner, a laser torch 304, for example a torch using a YAG type laser, the power of which is adapted to the cutting depth and to the nature of the sheet to be cut: thus a laser for 1000 W will allow cutting up to approximately 4 mm in steel and a 4000 W laser, cutting up to approximately 15 mm in steel.

  This torch 304 is supported by a bracket 306, itself suspended from a beam 308 resting on end ex25 rails 310. The bracket-beam assembly forms a mechanism with crossed movements making it possible to move the torch at will in two horizontal directions X and Y, so as to make the beam describe a predetermined path corresponding to the contour of the part to be cut. The position 30 in height of the torch 304 on the bracket 306 can also be adjusted in a vertical direction Z, depending on the cutting conditions required.

  Characteristically of the invention, the bracket also carries a pallet 312, which is in the form of an elongated arm extending in the direction transverse to the sheet metal strip (i.e. in the direction Y, the sheet metal strip extending parallel to the direction X). This pallet 312 has an upper face located a short distance from the underside of the sheet metal section 10 immobilized but not in contact with it, and over a transverse extent corresponding at least to the width of the sheet metal strip 10.

  This pallet 312 is intended to collect the pieces once cut which, under the effect of gravity, will fall on the upper face of the pallet once the cutting contour 10 has been completely traversed.

  A first feature of this pallet 312 is the presence of an orifice 314 located permanently in alignment with the laser beam produced by the torch 304, so that this beam does not risk damaging the pallet. The orifice 314 also allows the evacuation of the cutting slag which will be expelled, through this orifice, to the space located below the pallet, where they will then be recovered and will not come to mix with the uncut pieces, collected on the pallet 312. Insofar as the pallet is integral in its movements with the bracket 306 supporting the torch, it moves in synchronism with the latter and the orifice 314 therefore always remains vertically aligned on the axis of the laser beam. 25 Very advantageously, the pallet 312 is mounted on the bracket 306 by means of an articulation 316 which allows it to switch between on the one hand, a working position (position illustrated in FIG. 3 and in solid lines on the Figure 4) o it authorizes the reception by gravity of the cut pieces, and - on the other hand, a tilted position (position illustrated in Figure 2 and in dashed lines in Figure 4; the arrow W illustrates the tilting of the pallet 312) , o the cut piece (or series of pieces) 14 collected by the pallet can be removed, for example by dragging the pieces 14 by gravity onto a recovery tray 318 .

  The recovery plate 318 is advantageously a mobile plate, for example mounted on a longitudinal rail 320, to allow the transfer of the pieces collected on this plate from the cutting station 300 to the sorting and storage station 400.

  Advantageously, a plurality of containers, 402, 404, 406, each corresponding to a particular type of part, can be provided at this latter station. The recovery tray 318, after having collected the pieces of the same type produced at the cutting station 300 (FIG. 2), will then move along the rail 320 until it is above one of the containers 402, 404 or 406 (Figure 3), corresponding to the type of parts which have just been cut and into which it will pour the part or parts, for example with an opening bottom 20 326 controlled by the control cabinet 500, thus ensuring automatic sorting of the different shapes of parts.

  To prevent it from being damaged by the laser beam, and also to prevent it from collecting the cutting slag, the plate 318 is provided with a transverse slot 322 extending in the direction Y; when the torch is moved in the orthogonal direction X, the recovery plate 318 is also moved synchronously in this same direction (the rail 320 extending 30 parallel to X) so that the slot 322 is always located at the right of the torch 304.

  Furthermore, the cutting slag, after passing through the orifice 314 of the bracket 312 and the transverse slot 322 of the recovery tray 318, can be collected in a container 324 installed at the cutting station, under the recovery tray 318 .

  After cutting a piece or a series of pieces of the same type and collecting by the recovery plate 318 in the manner just described, the clips 302 for holding the sheet metal strip are released to advance the 5 section of sheet metal which has just been cut and bring a new, blank section, which will in turn be immobilized for a new cutting phase.

  The section which has just been cut (fall or "skeleton") 10 must be discarded, an operation which can be carried out automatically at station 400.

  A cutter 408 is provided for this purpose which, after advancing the sheet metal strip, cuts a skeleton section 16 of the same length which is then evacuated to a tank 410 after having slid over an inclined plane 412.

  The recovery of the falls can thus be carried out in an automatic and rational manner: in fact, the successive sections cut off by the cutter 408 are clean because devoid of slag, so can be easily stacked.

  It will be noted that the whole process of cutting up by the installation of the invention which has just been described can be controlled automatically and as a function of data produced by CAD / CAM software, which ensures great flexibility. manufacturing: cutting different types of parts on the same sheet section, changing the type of parts from one manufacturing to another, changing the shape of a part, etc. The implementation of this process also requires no consumables (unlike the spiked mats used until now), and the parts produced are perfectly clean, do not require any deburring or cleaning, and are therefore directly usable.

Claims (13)

claims   1. Installation for laser cutting a section of material (10) in sheet or plate, in particular a sheet section, this installation comprising a cutting station (300), with: - a laser torch (304) , comprising means for producing and projecting a laser beam vertically at a target point of the material section, - means for positioning the material section under the laser torch, and - a crossed movement mechanism (306, 308, 310 ), capable of controlling the torch in a horizontal plane in a first (X) and second (Y) horizontal direction so as to make the target point describe a series of predefined closed cutting paths defining the outline of the parts respective to be cut from the material section, installation characterized in that: - the positioning means comprise gripping and retaining means (302) of the material section 20 (10) pa r of the lateral edges thereof, these means being able to leave essentially free the space situated under the face of the material at least over the extent of the cutting paths, and - the cutting station comprises, under the section of maté25 riau and not in contact with it, a support pallet (312) having a collection surface of at least one piece after cutting, this surface being horizontal and its extent sufficient to allow it to collect by gravity and support the part cut after execution of the cutting path by the laser torch, the support pallet (312) being provided at the right of the target point with an orifice (314) for passage of the laser beam, also capable of letting the slag generated escape 35 target point during the material cutting process.   2. Laser cutting installation according to claim 1, characterized in that the support pallet (312) is a mobile pallet, capable of being moved in synchronism with the movement of the torch so as to maintain the passage opening in permanently positioned to the right of the laser beam.   3. Laser cutting installation according to revendica10 tion 2, characterized in that the laser torch (304) and the support pallet (312) are integral in their horizontal movements with a movable assembly (306) moved by the movement mechanism crossed (306, 308, 310).   4. Laser cutting installation according to claim 1, characterized in that the support pallet (312) is a tilting pallet between: - a first position, kept for the duration of the cutting process, where the collection surface is horizontal. to receive and support the cut piece (s), and - a second position, after completion of the cutting process, where this collection surface is inclined relative to the horizontal to laterally pour said 25 (said ) piece (s) cut to a recovery area located below the support pallet.   5. Laser cutting installation according to claim 4, characterized in that the cutting station (300) further comprises, in said recovery zone, a tray (318) for recovering and collecting the cut pieces, this tray being arranged below the tilting support pallet (312) so as to receive the pieces successively cut after completion of the cutting process when the support pallet is tilted to its second position.   6. laser cutting installation according to claim 5, characterized in that the recovery and collection plate (318) is a movable plate in a first horizontal direction (X) to allow the evacuation of the 5 pieces cut after completion of the cutting process.   7. laser cutting installation according to claim 6, characterized in that the movable plate (318) is capable of being moved in said first horizontal direction hori10 (X) in synchronism with the movements of the torch in this same first horizontal direction , the plate being provided with a transverse slot (322) extending in said second horizontal direction (Y) and forming a slot for the passage of the laser beam, also capable of letting escape the slag generated at the target point during the cutting process of the material.   8. Laser cutting installation according to claim 7, characterized in that the cutting station (300) further comprises, below the support pallet (312) and the recovery tray (318), a tank ( 324) for collecting the slag that has passed through the orifice (314) of the support pallet (312) and the slot (322) of the recovery tray (318).   9. Laser cutting installation according to claim 6, characterized in that the recovery plate (318) is an opening bottom plate (326), having - a closed position, for the duration of the cutting process, where the tray collects the successively cut pieces, and - an open position, after completion of the cutting process, where the collected cut pieces are evacuated to a storage area. 35 10. Laser cutting installation according to claim 5, characterized: - in that the installation further comprises, downstream of the cutting station (300), a sorting and storage station for the cut pieces (400), - and in that the recovery tray (318) is a movable plate capable of operating the transfer of the cut pieces between, on the one hand, the cutting station (300) and, on the other hand, a container (402) selectively chosen from a plurality of containers (402, 404, 406) arranged at the sorting and storage station (400).   11. Laser cutting installation according to claim 1, characterized in that the installation further comprises, downstream of the cutting station (300), a station for eliminating scrap material remaining after cutting the parts (410 , 412).   12. Laser cutting installation according to claim 1, characterized in that, the material being a sheet metal strip in the form of a continuous strip: - the installation further comprises, upstream of the cutting station (300), a station for storing and delivering a sheet metal strip (100), capable of supplying the cutting station in a controlled manner, and the gripping and retaining means (302) of the cutting station are means capable of being released during a phase of advancing a length of strip constituting said section of material to be cut, and activated during a subsequent phase of cutting this section of material.   13. laser cutting installation according to claim 12, characterized in that it further comprises, upstream of the cutting station (300), a straightening station (200) of the sheet metal strip delivered by the storage station 35 and debit (100).