Machine and method for laser-cutting a plate-shaped workpiece
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-23
- Publication Date
- 2026-04-08
Smart Images
Figure EP2024064186_05122024_PF_FP_ABST
Abstract
Description
[0001] MACHINE AND METHOD FOR LASER CUTTING A PLATE-SHAPED WORKPIECE
[0002] The invention relates to a machine and a method for laser cutting a plate-shaped, in particular metallic, workpiece.
[0003] The higher the laser power used in laser cutting and the thicker the workpiece to be cut, the greater the wear on the workpiece support bars of the grating support due to adhering slag or the damage to the workpiece support bars caused by the laser beam. As a result, the workpiece support bars must be replaced frequently, which can lead to significant machine downtime and significant costs. On the other hand, a large number of workpiece support bars or support pins are necessary to adequately support workpiece parts cut free from the workpiece, as well as any remaining workpiece parts, and to prevent the workpiece parts from tipping after they have been cut free.
[0004] WO 2019 025 327 A2 discloses a method for laser cutting a plate-shaped workpiece along a trajectory using a laser beam. To create a microjoint that is not located at the end of the trajectory and has a height less than the workpiece thickness during laser cutting of the workpiece, the laser radiation is reduced over a portion of the trajectory corresponding to the length of the microjoint from a higher laser power sufficient to cut through the workpiece to a lower laser power insufficient to completely cut through the workpiece, and then increased back to the higher laser power.
[0005] WO 2007 134 628 A1 discloses a workpiece support for holding a sheet-shaped workpiece in a machining system that processes the workpiece with a cutting beam. The workpiece support accommodates several adjacent support elements within a frame. These support elements have supporting points and form a support area for the workpiece. The working position of the support elements relative to the frame can be adjusted.
[0006] Furthermore, WO 2019 081 550 A1 discloses a workpiece support for a processing machine for flat workpieces. The workpiece support has a plurality of support points for the support elements forming the workpieces, which define a workpiece support plane for the flat workpiece. The workpiece support comprises a transfer device for transferring at least one of the support elements from a first position to at least one further position.
[0007] The object of the present invention is to provide a solution which enables a workpiece to be placed safely on a workpiece support with a particularly low risk of damage to the respective support elements of the workpiece support during laser cutting of the workpiece.
[0008] The problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are specified in the subclaims, the description, and the drawings. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.
[0009] The invention relates to a machine for laser cutting a plate-shaped, in particular metallic, workpiece. The machine comprises, in particular, a laser device which is configured to provide the laser beam for laser cutting the workpiece with a particularly high power, in particular a power of at least 15 kilowatts, in particular at least 24 kilowatts, in particular with a laser power of 40 to 50 kilowatts. It is therefore a so-called ultra-high-power laser device. This workpiece is, in particular, a sheet metal item from which at least one workpiece part is to be cut free in order to produce a component. The machine is configured to cut the workpiece part free using a laser beam. The machine comprises a workpiece support with several support elements onto which the workpiece can be placed during laser cutting.In other words, the workpiece is placed on the respective support elements when placed on the workpiece support. The support elements can be designed as support bars or support pins. To minimize the risk of damage to the respective support elements during laser cutting of the workpiece, the workpiece is held by a very small number of support elements. The fewer support elements used to hold the workpiece, the fewer support elements are used.
[0010] Support elements, in turn, wear out during laser cutting of workpieces placed on the workpiece support.
[0011] In order to use particularly few support elements for stabilizing the workpiece, it is provided that directly adjacent support elements, on which the workpiece is placed, have a distance of at least 100 millimeters, in particular a distance of at least 200 millimeters, in particular a distance of at least 500 millimeters, in particular a distance of at least
[0012] 700 millimeters from each other. In order to prevent the cut-out workpiece parts from tilting relative to one another or to a remaining piece of the workpiece despite this large distance between the directly adjacent support elements carrying the workpiece, the machine is provided with a control device which is set up to control the laser cutting in such a way that the cut-out workpiece parts of the workpiece are connected to the remaining piece of the workpiece via at least one material web. In this case, the material web only extends over part of the thickness of the workpiece. Depending on how large the proportion of the workpiece thickness is that the material web extends over in height, the material web is a microjoint or a nanojoint. A nanojoint has a lower height than a microjoint.The at least one material web ensures stabilization of the cut-free workpiece part via the remaining piece of the workpiece, whereby the remaining piece of the workpiece can rest on at least one support element. The respective positions of the material webs can be selected depending on the cutting length in one spatial direction when cutting the workpiece part free. This means that, starting from a material web as the starting point, the next material web is placed after a cutting length in one spatial direction of, for example, a maximum of 100 millimeters to ensure sufficient stabilization of the cut-free workpiece part.
[0013] The provision of at least one material web thus allows only a very small number of support elements to be required to adequately stabilize released workpiece parts and prevent them from tipping. The remaining piece of the workpiece can also be referred to as a so-called residual skeleton. The described machine thus allows the workpiece to be supported on very few support elements during laser cutting, and the respective cut-free workpiece parts are sufficiently stabilized due to the at least one material web. In addition, only a very small number of support elements are affected and potentially worn during laser cutting of the workpiece.
[0014] In a possible development of the invention, it is provided that the support elements are made of an aluminum alloy or of copper or a copper alloy. Aluminum and copper are materials with particularly good thermal conductivity, so that the risk of melting of areas of the support elements, in particular of tips of the support elements, upon contact with the laser beam is particularly low. Furthermore, the risk of slag caking is particularly low with support elements made of an aluminum alloy or a copper-containing material. As a result, the workpiece support comprising these support elements has a particularly long service life. Alternatively, the support elements can be made of steel.
[0015] In a further possible embodiment of the invention, the number and spacing of the support elements are selected such that any possible sagging of the workpiece on the workpiece support is limited to a maximum of 20 millimeters. In other words, the maximum distance between adjacent support elements is determined so that the sagging of the workpiece on the workpiece support is less than or equal to 20 millimeters. This determined maximum spacing of the support elements is then maintained for those support elements on which the workpiece rests during processing. This ensures that the workpiece does not sag so much downwards that a cut is lost at a cutting contour, for example as a result of the focus of the laser beam no longer being correctly positioned.Excessive sagging of the workpiece can result in the remaining piece, along with the connected workpiece parts, no longer being reliably removed from the workpiece support after machining using an automation device, such as a rake or suction gripper. Furthermore, a workpiece sag of more than 20 millimeters could lead to the workpiece parts tipping. By arranging the support elements in such a way that the workpiece sag is limited to a maximum of 20 millimeters, precise and error-free machining of the workpiece can be achieved, while the risk of damage to cut-out workpiece parts can be kept particularly low.
[0016] In a further possible embodiment of the invention, the support elements are designed as support webs with a width of at least three millimeters and / or a height of at least 100 millimeters, in particular at least 115 millimeters, in particular at least 150 millimeters. This design of the support webs allows workpieces with a thickness of more than 20 millimeters to be supported by a particularly small number of support webs, with respect to their weight. This makes it possible to reliably support particularly thick and consequently heavy workpieces using fewer support webs.
[0017] In a further possible embodiment of the invention, it is provided that a number and a spacing of the support elements are selected depending on a size and / or a thickness of the workpiece. The number of support elements and the spacing between respective adjacent support elements are thus selected such that a given workpiece can be held particularly securely by means of the support elements, depending on the size and / or thickness of the workpiece. For workpieces with a thickness of less than three millimeters, the spacing of the support elements can be, for example, at least 100 millimeters, in particular at least 200 millimeters, in particular at least 500 millimeters. If a sufficient number of microjoints and / or nanojoints are provided, the spacing of the support elements for these workpiece thicknesses can be, in particular, up to 750 millimeters, in particular up to 800 millimeters.For workpieces with a thickness of less than three millimeters, the spacing between the support elements should be less than 1,500 millimeters to prevent excessive sagging of the workpiece, especially below 20 millimeters. For workpieces with a thickness of at least three millimeters, the spacing between the support elements can be up to 1,500 millimeters or more.
[0018] In a further possible embodiment of the invention, it is provided that at least one of the support elements is held by a support element carrier and is designed to be movable relative to the support element carrier. In this case, the movable support element can be guided on the support element carrier. The support element carrier can be designed in particular as a support frame. Within the support frame, the support elements held by the support frame can be moved relative to the support frame. The support elements can be moved before the workpiece is placed on the workpiece support and thus aligned relative to the support element carrier and relative to one another, or they can be aligned relative to the support element carrier and relative to one another while the workpiece is resting on the workpiece support, in particular during laser cutting of the workpiece.Because the support elements are designed to be movable, they can be arranged in such a way that very few of the support elements are overlapped by the laser beam during laser cutting of the workpiece. This makes it possible to keep the risk of damage to the respective support elements particularly low. In particular, the support elements can be arranged in such a way that the remaining piece of the workpiece is stabilized by means of them. It is possible that direct stabilization of cut-out workpiece parts by means of the support elements does not occur. The at least one cut-out workpiece part can be stabilized via the at least one material web via which the workpiece part is connected to the remaining piece of the workpiece.The mobility of the at least one support element further enables this support element to be moved during the laser cutting of the workpiece arranged on this support element, whereby this support element can be moved from an area in which the cutting contour has yet to be cut by the laser beam to an area in which the cutting contour has already been cut by the laser beam. This makes it particularly easy to prevent the laser beam from overlapping the movable support element.
[0019] In this context, a further possible embodiment of the invention provides that the movable support element has at least one roller which provides a support surface for the workpiece. This means that the workpiece is placed on the at least one roller of the movable support element. If the support element is thus moved relative to the support element carrier while the workpiece is placed on the support element, the roller rolls over the workpiece. As a result, the risk of the workpiece being scratched by the support element being moved relative to the workpiece can be kept particularly low. When the support element is moved relative to the workpiece, the roller is the only contact surface between the support element and the workpiece and rolls over the surface of the workpiece.The risk of damage to the workpiece when moving the movable support element relative to the support element carrier can thus be kept particularly low.
[0020] In a further possible embodiment of the invention, the machine comprises at least one extraction channel element which is movable relative to the workpiece support and by means of which an extraction region into which air is extracted during machining of the workpiece can be specified. The extraction region can be delimited by means of the extraction channel element. By moving the extraction channel element relative to the workpiece support, the position and / or dimensions of the extraction region can be adjusted. In this case, the extraction region is adjusted in particular such that the extraction region is located below the region of the workpiece which is being cut by the laser beam at the respective time. As a result, dust and / or gases generated during laser cutting can be extracted particularly reliably.
[0021] In this context, a further possible embodiment of the invention can provide for the suction channel element to be configured to act on the movable support element, whereby the support element and the suction channel element can be moved together relative to the support element carrier. For example, the suction channel element can be attached to the support element. Alternatively, the suction channel element can be moved vertically so that, during a lateral movement, it abuts the support element, in particular the support web, and thereby displaces it. The suction area defined by the suction channel element is thus related to the position of the movable support element.By arranging the extraction channel element in such a way that the extraction area is located below the respective area of the workpiece being processed by the laser beam, the extraction channel element laterally delimiting the extraction area and the movable support element connected to the extraction channel element are arranged laterally next to the area of the workpiece in which the workpiece is being processed by the laser beam. The risk of the laser beam crossing the movable support element and the extraction channel element, and the resulting damage to the support element or the extraction channel element, can thus be kept particularly low. This allows a particularly long service life of the machine to be achieved. The extraction channel element can connect to and release the connection to the support element in a controlled manner.If the support element were to be moved along with the extraction channel element, support for the workpiece in the cutting area would always be guaranteed. In particular, at least one movable support element is moved simultaneously with the laser cutting head.
[0022] The invention further relates to a method for laser cutting a plate-shaped, in particular metallic, workpiece by means of a machine as has already been described in connection with the machine according to the invention. In the method, the workpiece is placed on the workpiece support, and at least one workpiece part is cut free from the workpiece. This cut-free at least one workpiece part remains connected to a remaining piece of the workpiece via at least one material web, in particular a microjoint or a nanojoint, at least until the laser cutting is completed. The provision of at least one material web makes it possible for the workpiece to be held on the workpiece support with particularly few support elements, or for the support elements by means of which the workpiece is held to be spaced particularly far apart from one another.This allows the number of support elements damaged during laser cutting of the workpiece to be kept to a particularly low level. Furthermore, the at least one material web enables particularly secure stabilization of the at least one cut-free workpiece part on the remaining piece of the workpiece and, consequently, a particularly low risk of the cut-free workpiece part tipping over. The method provides for the cut-free workpiece parts to be held by material webs on the remaining piece of the workpiece, in particular on the remaining skeleton, and for only enough support elements to prevent deflection of the workpiece parts beyond a predetermined maximum value.
[0023] In a possible further development of the invention, it is provided that the support elements of the workpiece support are arranged in such a way that the remaining piece is carried by the support elements and the at least one cut-free workpiece part does not rest on the support elements. The at least one workpiece part is thus held to the remaining piece only via the provided material web. Because only the remaining piece is directly supported by the support elements, the risk of a support element being overcut by the laser beam used during laser cutting and thus coming into contact with the laser beam in particular can be kept particularly low. As a result, the risk of damage to the support elements due to slag caking on or melting as a result of direct contact with the laser beam can be kept particularly low.Because the support elements are arranged in such a way that they only support the remaining piece of the workpiece formed after laser cutting, they can be easily knocked out downwards with a hammer in order to sort the workpiece parts.
[0024] In a further possible embodiment of the invention, it is provided that the support elements of the workpiece support are arranged in such a way that a cutting contour for laser cutting does not directly cross the support elements. This means that it is determined where the cutting contour runs along the workpiece that is placed or is to be placed on the workpiece support. Respective support elements of the workpiece support are positioned in such a way that the cutting contour does not run directly above the support elements, which would prevent the laser beam from crossing the support elements when cutting the cutting contour. In other words, the support elements are arranged in such a way that the laser beam is not guided over the support elements. Respective areas of the workpiece that are arranged directly above the support elements and thus overlap the support elements upwards are free of the cutting contour.This prevents the support elements from interacting with the cutting process. As a result, the risk of damage to the support elements of the workpiece support during laser cutting of the workpiece can be kept particularly low. In this case, it can be provided that the support elements support both the remaining piece resulting from laser cutting and the at least one cut-free workpiece part. The position of the respective support elements can be provided by a programming system, and the arrangement of the respective support elements relative to the support element carrier can be implemented via simple plug-in connections or with actuators for the support elements.
[0025] In a further possible embodiment of the invention, it is provided that the at least one workpiece part remains connected to the remaining piece of the workpiece via at least two material webs if the thickness of the workpiece is less than four millimeters. With workpiece thicknesses of less than four millimeters, cut-out workpiece parts can bend, tilt or hang downwards out of the remaining piece of the workpiece if they are only held on the remaining piece by a material web and are not supported in a suitable position by a support element, in particular a support web or a support pin, for example due to the fact that the respective workpiece part is smaller in a corresponding spatial direction than the distance between two immediately adjacent support elements.Above a certain part size, the holding force of a single material web may not be sufficient to securely hold the cut-out workpiece part to the remaining piece of the workpiece, especially if there is no supporting support element underneath the cut-out workpiece part. In these cases, at least a second material web should be used. Nanojoints or microjoints can be used as material webs. In particular, the width of each material web must be limited such that the at least one cut-out workpiece part can be removed from the remaining piece without great effort and without damaging a part edge, or with only very slight damage to a part edge. The number of each material web is selected in particular such that the sagging of the cut-out workpiece parts is limited to a maximum sag depth of 20 millimeters.For workpiece thicknesses of less than four millimeters, at least two material bars are provided to securely fix the workpiece parts to the remaining piece. For larger workpiece thicknesses, workpiece parts longer than
[0026] 100 millimetres and do not have any support by a support element, are supported in addition to the first material web by a second material web, wherein these mutually adjacent material webs in particular have a distance of at least
[0027] 100 millimeters from each other, in particular a distance of at least 200 millimeters from each other. As the size of the workpiece parts increases, the material web can be made wider so that the respective cut-out workpiece parts can be securely held on the remaining piece, in particular on the residual skeleton. The width of the respective material web runs in particular in the direction of the cutting contour in the area in which the material web is provided in the cutting contour. When planning the microjoints, a minimum microjoint width can be taken into account depending on any plastic deformation of the microjoint and the force exerted by the cutting gas. This determination method can be applied analogously to nanojoints. The width of a nanojoint is chosen to be less than three millimeters, in particular to prevent a cut break when the nanojoint is created.
[0028] In a further possible embodiment of the invention, it is provided that the at least one material web provided has a height which is less than a thickness of the workpiece. This means that the material web only extends over part of the thickness of the workpiece. Depending on the proportion of the workpiece thickness over which the material web extends in height, the material web is a microjoint or a nanojoint. A nanojoint has a lesser height than a microjoint. The at least one material web ensures that the cut-free workpiece part is stabilized via the remaining piece of the workpiece, wherein the remaining piece of the workpiece can rest on at least one support element.
[0029] By using material webs, in particular microjoints or nanojoints, it is possible to significantly reduce the number of required support elements and consequently the overlap of the cutting contour with the support elements, thus reducing or even completely avoiding wear on the support elements. Cut-free workpiece parts must be securely held on the remaining piece via the at least one material web so that, on the one hand, they do not fall downwards and, on the other hand, they are not detached from the remaining piece by the cutting gas, in particular are not forced out of the residual skeleton or tilted relative to the remaining piece. These boundary conditions must be taken into account in order to determine the extent and number of required material webs depending on the part size and contour of the workpiece parts to be cut free, the workpiece thickness of the workpiece and the distance between the support elements.
[0030] If it is known exactly where the support elements are arranged relative to the workpiece, then the workpiece parts to be cut free can be placed largely between the support elements when planning the workpiece parts in a programming system, so that there is little or no interaction between the laser beam and the support elements.
[0031] In a further possible embodiment of the invention, it is provided that during a positioning movement of a laser cutting head of the machine, a cutting gas pressure of a cutting gas is reduced compared to a cutting gas pressure of the cutting gas during laser cutting of the workpiece, while the laser cutting head is moved above the at least one cut-free workpiece part during the positioning movement. In other words, when moving over finished cut workpiece parts that are held to the remaining piece of the workpiece via one or more material webs, the cutting gas pressure of the laser cutting head is reduced, thereby preventing bending or tilting of the cut-free workpiece parts—caused by the impact of cutting gas on the workpiece parts.In particular, the cutting gas can be completely turned off when positioning the laser cutting head, in particular when positioning the laser cutting head between the end of a cut and the start of a new cut. In particular, the cutting gas is turned off when positioning the laser cutting head when the laser cutting head is moved over a workpiece with a thickness of four to eight millimeters, in particular with a thickness of less than four millimeters, during its positioning movement. If the cutting gas is completely turned off during the positioning movement of the laser cutting head, then for workpieces in a thickness range of four to eight millimeters, it can be provided that each cut-out workpiece part is held to the remaining part of the workpiece by just a single material web.This means that very few material webs need to be kept during laser cutting, which means that after laser cutting is complete, the cut-out workpiece parts can be separated from the remaining piece particularly easily.
[0032] Further features of the invention can be derived from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.
[0033] The drawing shows:
[0034] Fig. 1 is a schematic perspective view of a first embodiment of a workpiece support for a workpiece with a plurality of support elements onto which a workpiece can be placed during laser cutting;
[0035] Fig. 2 is a schematic perspective view of the workpiece support in a second embodiment; and
[0036] Fig. 3 is a schematic perspective view obliquely from above of a workpiece placed on the workpiece support, which is laser cut by means of a laser device.
[0037] Identical or functionally equivalent elements are provided with the same reference numerals in the figures.
[0038] 1 and 2 each show a workpiece support 10 with a plurality of support elements 12, on which a workpiece 18 can be placed during laser cutting. The workpiece support 10 is part of a machine 14 for laser cutting a plate-shaped, in particular metallic workpiece, in this case a sheet metal. The machine 14 is a 2D laser cutting machine. Fig. 3 shows a section of the machine 14 in a perspective view obliquely from above. It can be seen that the machine 14 comprises a laser cutting head 16, by means of which a laser beam can be directed onto the workpiece 18 to be machined. By means of the laser beam, respective workpiece parts 20 can be cut free from the workpiece 18, which remain connected to a remnant piece 22 of the workpiece 18 via at least one material web. The remnant piece 22 is in particular a remnant skeleton.In the present case, the laser cutting head 16 is configured to provide the laser beam with particularly high power, in particular a power of at least 15 kilowatts, in particular of at least 24 kilowatts, in particular of at least 40 kilowatts. If, at such high laser powers, the laser beam comes into contact with the support elements 12 or if slag produced during laser cutting comes into contact with the support elements 12, this can lead to damage to the support elements 12. As a result of the damage to the support elements 12, these support elements 12 must be removed and thus represent a wearing component of the machine 14. It is therefore provided to create a machine 14 or a method for laser cutting the workpiece 18 in which particularly few support elements 12 are worn.
[0039] In the present case, the respective support elements 12, as can be clearly seen in Figs. 1 and 2, are designed as respective support webs with tips projecting in the support direction or upwards, wherein the workpiece 18 can be placed on these tips. Due to the design of the respective support elements 12 as the support webs with the tips, direct contact of the workpiece 18 with the support elements 12 can be kept particularly low. As a result, the risk of damage to the workpiece 18 due to contact with the respective support webs, for example, scratching, can be kept particularly low.
[0040] The support elements 12 can, as shown in Fig. 1, be fixed relative to a support element carrier 24 and held on this support element carrier 24. In the second embodiment of the workpiece support 10 shown in Fig. 2, it is provided that at least one of the support elements 12 is movable relative to the support element carrier 24 on which the support elements 12 are held. As a result, a relative position of the support elements 12 relative to one another can be adjusted. Furthermore, the at least one movable support element 12 can be adjusted in its relative position to the workpiece 18 placed on the workpiece support 10 by moving it relative to the support element carrier 24. The support element 12, which is movable relative to the support element carrier 24, in particular has at least one roller which provides a support surface for the workpiece 18, whereby the workpiece 18 can be placed onto this support element 12 via the roller.When this support element 12 is moved relative to the workpiece 18, the risk of scratching the workpiece 18 can be kept particularly low, since the relative movement of the support element 12 relative to the workpiece 18 is implemented by the roller rolling over the surface of the workpiece 18. This minimizes the respective frictional forces of the support element 12 relative to the workpiece 18 when the support element 12 is moved relative to the workpiece 18.
[0041] In order to minimize wear on the respective support elements 12 of the machine 14, it is provided that the workpiece 18 is placed on only a very small number of support elements 12. For this purpose, it is provided that two directly adjacent support elements 12, each of which supports the workpiece 18, are spaced apart by at least 100 millimeters, in particular a distance of at least 200 millimeters, in particular a distance of at least 500 millimeters, in particular a distance of at least 700 millimeters. The number and spacing of the support elements 12 are selected such that any possible sagging of the workpiece 18 on the workpiece support 10 is limited to a maximum of 20 millimeters.In this way, damage to the workpiece 18 caused by a cut break can be particularly well avoided, and, moreover, a particularly simple and precise automated removal of the workpiece 18 from the workpiece support 10 after laser cutting can be ensured.
[0042] In order to avoid the risk of respective cut-free workpiece parts 20 of the workpiece 18 tilting towards a remaining piece 22 of the workpiece 18 or to enable sufficient stabilization of cut-free workpiece parts 20 of the workpiece 18 via the remaining piece 22 of the workpiece 18, it is provided that the machine 14 comprises a control device (not shown in the figures), which is configured to control the laser cutting in such a way that cut-free workpiece parts 20 of the workpiece 18 remain connected to the remaining piece 22 of the workpiece 18 via at least one material web. In this case, the cut-free workpiece parts 20 remain connected to the remaining piece 22 of the workpiece 18 via the at least one material web at least until the completion of the laser cutting.It is provided that the at least one workpiece part 20 remains connected to the remaining piece 22 via at least two material webs if the thickness of the workpiece 18 is less than four millimeters.
[0043] The support elements 12 are in this case formed from an aluminum alloy or from a copper-containing material (e.g. copper). In order to enable particularly good stabilization of heavy workpieces 18, it is provided that the support elements 12 are designed as support webs with a width of at least three millimeters and / or with a height of at least 100 millimeters, in particular at least 115 millimeters, in particular at least 150 millimeters. A number of and a distance of the support elements 12 from respectively adjacent support elements 12 is selected depending on a size and / or a thickness of the workpiece 18. It is provided in particular that the support elements 12 of the workpiece support 10 are arranged such that the remaining piece 22 is carried by the support elements 12. The at least one workpiece part 20 does not rest on the support elements 12.Furthermore, it can be provided that the support elements 12 of the workpiece support 10 are arranged in such a way that a cutting contour for laser cutting does not directly intersect the support elements 12. The workpiece 18 is to be cut along the cutting contour using the laser beam.
[0044] To prevent tilting of already cut workpiece parts 20 relative to the remaining piece 22, it can be provided that, during a position and movement of the laser cutting head 16, a cutting gas used during laser cutting is switched off, or a cutting gas pressure of the cutting gas is set lower during positioning compared to laser cutting. In particular, the cutting gas pressure of the cutting gas can be reduced, or the cutting gas can be completely switched off, at least while the laser cutting head 16 is moved above the at least one cut workpiece part 20 during the positioning movement, and thus a cutting gas stream impinges directly from above on the cut workpiece part 20, or would impinge if the cutting gas were activated.
[0045] As can be seen in Fig. 3, the machine 14 can comprise at least one, in particular a plurality of, extraction channel elements 26. The extraction channel elements 26 are designed to be positioned below the workpiece support 10 and to delimit an extraction region 28 from which air is extracted during the processing of the workpiece 18, in particular during laser cutting. In the present case, the extraction channel elements 26 are plate-like elements which are designed to laterally delimit the extraction region 28. In the present case, the extraction channel elements 26 are provided from respective metal sheets. In other words, the extraction region 28 is located between two adjacent extraction channel elements 26. In the present case, an extraction box 30 is arranged below the extraction channel elements 26.The suction channel elements 26 can be attached to the underside of respective support elements 12, whereby the respective suction channel elements 26 can be moved together with the support elements 12 relative to the support element carrier 24. The support elements 12 can be positioned during laser cutting or before laser cutting, wherein an arrangement of the respective movable support elements 12 is selected depending on the cutting contour. Moving the at least one support element 12 during laser cutting enables the at least one cut-free workpiece part 20 to be sufficiently stabilized without having to provide many material webs. Thus, particularly few material webs can be provided when cutting free the respective workpiece part 20.In particular, the at least one cut-free workpiece part 20 can be stabilized after cutting by means of a movable support element 12, which is moved beneath the cut-free workpiece part 20 while cutting is performed at another location on the workpiece 18 by means of the laser cutting head 16. During laser cutting, the workpiece 18 can be clamped onto the workpiece support 10 by means of clamping claws or grippers in order to prevent any lateral movement of the workpiece 18 relative to the workpiece support 10.
[0046] In this case, the support element carrier 24 is designed as a pallet with support strips as support elements 12. The extraction channel elements 26 can be latched onto the support strips with a simple lift. Through consistent use of nanojoints, the number of support bars can be massively reduced. This reduces the potential for buildup. Furthermore, the mobility of the support elements 12 allows them to be moved relative to the laser cutting head 16, thereby minimizing the risk of buildup and splashes on the workpiece 18 and on the support elements 12.
[0047] Overall, the invention shows how reduced support bars can be implemented in the machine 14.
[0048] LIST OF REFERENCE SYMBOLS
[0049] 10 Workpiece support
[0050] 12 Support element 14 Machine
[0051] 16 laser cutting head
[0052] 18 Workpiece
[0053] 20 workpiece part
[0054] 22 Remaining piece 24 Support element carrier
[0055] 26 Suction duct element
[0056] 28 Extraction area
[0057] 30 suction box
Claims
PATENT CLAIMS 1. Machine (14) for laser cutting a plate-shaped, in particular metallic, workpiece (18), with a workpiece support (10) with a plurality of support elements (12) onto which the workpiece (18) can be placed during laser cutting, wherein immediately adjacent support elements (12) are spaced from one another by a distance of at least 100 millimeters, in particular a distance of at least 200 millimeters, in particular a distance of at least 500 millimeters, in particular a distance of at least 700 millimeters, and a control device which is designed to control the laser cutting in such a way that cut-free workpiece parts (20) of the workpiece (18) remain connected to a remaining piece (22) of the workpiece (18) via at least one material web.
2. Machine (14) according to claim 1, characterized in that the support elements (12) are formed from an aluminum alloy or from copper or a copper-containing material.
3. Machine (14) according to claim 1 or 2, characterized in that a number and a spacing of the support elements (12) is selected such that a possible sagging of the workpiece (18) on the workpiece support (10) is limited to a maximum of 20 millimeters.
4. Machine (14) according to one of the preceding claims, characterized in that the support elements (12) are designed as support webs with a width of at least 3 millimeters and / or with a height of at least 100 millimeters, in particular at least 115 millimeters, in particular at least 150 millimeters.
5. Machine (14) according to one of the preceding claims, characterized in that a number and a spacing of the support elements (12) is selected depending on a size and / or a thickness of the workpiece (18).
6. Machine (14) according to one of the preceding claims, characterized in that at least one of the support elements (12) is held by a support element carrier (24) and is designed to be movable relative to the support element carrier (24).
7. Machine (14) according to claim 6, characterized in that the movable support element (12) has at least one roller which provides a support surface for the workpiece (18).
8. Machine (14) according to one of the preceding claims, characterized in that at least one suction channel element (26) is provided which is movable relative to the workpiece support (10), by means of which a suction region (28) in which air is sucked out during machining of the workpiece (18) can be specified.
9. Machine (14) according to claim 8 with reference to claim 6 or 7, characterized in that the suction channel element (26) is designed to act on the movable support element (12), whereby the support element (12) and the suction channel element (26) can be moved together relative to the support element carrier (24).
10. Method for laser cutting a plate-shaped, in particular metallic, workpiece (18) by means of a machine (14) according to one of the preceding claims, in which the workpiece (18) is placed on the workpiece support (10) and at least one workpiece part (20) is cut free from the workpiece (18), which remains connected to a remaining piece (22) of the workpiece (18) via at least one material web at least until the end of the laser cutting.
11. Method according to claim 10, characterized in that the support elements (12) of the workpiece support (10) are arranged such that the remaining piece (22) is carried by the support elements (12) and the at least one workpiece part (20) does not rest on the support elements (12).
12. Method according to claim 10 or 11, characterized in that the support elements (12) of the workpiece support (10) are arranged in such a way that a cutting contour for the laser cutting does not directly cross the support elements (12).
13. Method according to one of claims 10 to 12, characterized in that the at least one workpiece part (20) remains connected to the remaining piece (22) of the workpiece (18) via at least two material webs if the thickness of the workpiece (18) is less than 4 millimeters.
14. Method according to one of claims 10 to 13, characterized in that the at least one material web provided has a height which is less than a thickness of the workpiece (18).
15. Method according to one of claims 10 to 14, characterized in that during a positioning movement of a laser cutting head (16) of the machine (14), a cutting gas pressure of a cutting gas is reduced in comparison to a cutting gas pressure of the cutting gas during laser cutting of the workpiece (18), while the laser cutting head (16) is moved above the at least one cut-free workpiece part (20) during the positioning movement.