Abstract:
A laser processing machine has an expanded operating space so that larger workpieces can be processed and/or the spatial requirement for the laser processing machine is reduced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of, and claims priority under 35 U.S.C. §120 from, PCT/EP2009/003206, filed on May 5, 2009, and designating the U.S., which claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2008 022 449.9, filed on May 8, 2008. The contents of the prior applications are hereby incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a laser processing machine having expanded work space. 
       BACKGROUND 
       [0003]    There are known, for example, from JP 03-138092 A, laser processing machines in which a workpiece that is to be processed is placed on a workpiece support. The laser processing machine can include a portal arranged above the workpiece support. The portal can be moved in the longitudinal direction of the workpiece. A laser processing head can be arranged at one side of the portal. The laser processing head can be moved relative to the workpiece by the movement of the portal. Using the laser processing head, it is possible to process a workpiece. With the known configuration of a laser processing machine, workpieces that are smaller than the base surface of the laser processing machine can be processed. 
         [0004]    DE 196 20 391 A1 discloses a device for processing planar objects which comprise a non-metal carrier material, such as, for example, paper, cardboard, plastics material or the like. The device can have an operating plane in which an object to be processed is arranged. The device can include an arm that extends over the operating plane. The arm can be guided so as to be able to be displaced over the entire processing plane in one direction. The device can also include a processing head for processing the object. The processing head can be guided so as to be able to be displaced on the arm at right angles relative to the movement direction thereof. In particular, a plurality of processing heads may be provided on the arm. The processing heads can be constructed for drawing, cutting or grooving the non-metal carrier material. 
         [0005]    DE 36 04 470 A1 discloses a material processing station having a processing unit that can be positioned along three mutually perpendicular axes. To this end, a support is generally arranged perpendicularly and provided with horizontally extending spindle drives for a sliding member, which in turn is provided with spindle drives and can be displaced perpendicularly relative to the floor. This sliding member receives the processing unit, which in turn can be displaced perpendicularly relative to the plane of the support. 
         [0006]    WO 2005/099979 A1 discloses a device in which two laser beam processing heads are arranged on a common sliding member. 
         [0007]    DE 203 06 581 U1 discloses a laser welding device for welding components of vehicle bodies, including a plurality of laser welding heads that are constructed as remote lasers and are arranged with spacing relative to the component. 
         [0008]    DE 100 06 516 A1 discloses a method for processing workpieces by means of a plurality of laser beams, a plurality of laser beams being combined via a beam unifier and being directed onto a workpiece via a common beam guide. 
         [0009]    DE 10 2005 025 506 A1 discloses a laser processing machine that is configured to process a sheet-like workpiece. The sheet-like workpiece is secured to a processing table by means of relative movement of the processing table and laser collimation and positioning means and, by repeatedly moving the sheet-like workpiece in the longitudinal direction, to fix a region that is intended to be processed next in position on the processing table when the processing of a region to be processed is completed. 
       SUMMARY 
       [0010]    In general, this invention relates to a laser processing machine having an expanded work space. 
         [0011]    One aspect of the present invention provides a laser processing machine that has an expanded operating space so that larger workpieces can be processed and/or the spatial requirement for the laser processing machine is reduced. 
         [0012]    According to one aspect, a laser processing machine has at least one laser processing head arranged at each of two opposing sides of a carrier structure. The laser processing machine also includes a beam deflector by means of which a laser beam of a beam generator can be switched between the laser processing heads. The operating ranges of the mutually opposing laser processing heads overlap and extend each other in a gap-free manner. A machine base surface and the operating range, which is substantially defined by the movability of a laser processing head in the X and Y direction, can thereby almost be caused to overlap. It is consequently possible either for the operating range to be increased so that larger workpieces can be processed or for the spatial requirement, in particular the base surface-area requirement of the laser processing machine, to be decreased. The technical advantage in terms of production is that, as before, a machine with laser processing heads on only one side of the carrier structure can be produced and the customer can decide very late whether he also wishes needs/to have laser processing heads at the opposing side. 
         [0013]    Another aspect features a laser processing machine that includes a workpiece apparatus (e.g., a workpiece support and/or a workpiece retaining member) for supporting or retaining a workpiece to be processed, a laser beam generator, a carrier structure carrying at least two laser processing heads for directing a laser beam from the laser beam generator at a workpiece supported on or retained by the workpiece apparatus, and a beam deflector operable to switch the laser beam between the laser processing heads. Relative positioning of the laser processing heads and the workpiece apparatus is alterable to direct the laser beam to different points. The laser processing heads include a first laser processing head on one side of the carrier structure, and a second laser processing head on another side of the carrier structure. 
         [0014]    In another aspect, a laser processing machine includes a workpiece apparatus (e.g., a workpiece support and/or a workpiece retaining member) for supporting or retaining a workpiece to be processed, a laser beam generator, a carrier structure carrying at least two laser processing heads for directing a laser beam from the laser beam generator at a workpiece supported on or retained by the workpiece apparatus, and a beam deflector operable to switch the laser beam between the laser processing heads. Relative positioning of the carrier structure and the workpiece apparatus is alterable to direct the laser beam to different points. The laser processing heads are spaced apart along a tool axis, such that a combined distance traversable by the first and second laser processing heads along the tool axis is greater than an extent of relative movement between the carrier structure and the workpiece apparatus along the tool axis. 
         [0015]    Implementations may provide one or more of the following features and/or to advantages. 
         [0016]    In some implementations, the beam deflector can be controlled and may be arranged so as to be able to move so that the laser beam can be redirected onto one laser processing head or the other. 
         [0017]    In certain implementations, the carrier structure carries at least two laser processing heads on each of two sides of the carrier structure. Owing to this multiplication of the laser processing heads, particularly good use can be made of the operating range. The base surface-area of the laser processing machine can be substantially identical to the operating range of the laser processing heads. In addition, the workpiece can be processed at the same time at several locations so that a higher processing rate can be implemented. 
         [0018]    In some implementations, the laser processing heads are movable along the carrier structure. This can allow the laser processing head to access almost all regions of a workpiece. In some cases, it may be simpler to move the laser processing heads along the carrier structure than to move the workpiece relative to the carrier structure since a greater mass may thereby have to be moved. 
         [0019]    In certain implementations, laser processing heads that are arranged at the same side of the carrier structure are movable independently of each other or in a coupled state. During the processing of the workpiece, it is possible to switch from one laser processing head to the other laser processing head. 
         [0020]    In some cases, the switching from one laser processing head to the other laser processing head can also be carried out in another axial direction, such as from one laser processing head that is arranged at a first side of the carrier structure to a laser processing head that is arranged at the opposite side of the carrier structure. Laser processing heads that are arranged at different sides of the carrier structure can be moved along the carrier structure either in a coupled state or independently of each other. 
         [0021]    In some implementations, at least one of the laser processing heads has an additional control axis. It is thereby possible to carry out a highly dynamic workpiece processing operation in a locally limited manner. 
         [0022]    In certain implementations, the carrier structure is movable relative to the workpiece apparatus. It is thereby possible to make even better use of the operating space. 
         [0023]    In certain implementations, a plurality of the laser processing heads can be mounted to the carrier structure on a common sliding member. Consequently, the laser processing heads can be moved together relative to the carrier structure by means of the common sliding member. 
         [0024]    In some implementations, at least one of the mounted laser processing heads is movable relative to the sliding member, e.g., in a linear manner. Consequently, the relative position of one laser processing head relative to the other laser processing head on the same sliding member can be changed. Furthermore, a highly dynamic workpiece processing operation may be possible. 
         [0025]    In certain implementations, the mounted laser processing heads are movable relative to the sliding member independently of each other or in a coupled state, e.g., in a linear manner. 
         [0026]    If at least two laser processing heads are provided, there are various possibilities for adjusting power, depending on the workpieces to be processed. 
         [0027]    In some implementations, the laser processing machine includes at least two beam generators. For example, it is possible to provide as many beam generators as there are laser processing heads. The beam generators may be fixedly associated with a laser processing head. By skillfully nesting workpieces of the same type, it is possible to process two workpieces at the same time, by fitting two beam generators. It is further conceivable for the power of a beam generator to be divided at an appropriate location and to be redirected to two laser processing heads. To this end, the laser processing machine may also include a beam splitter module that is arranged to split a laser beam between the processing heads. 
         [0028]    In some cases, it is also possible to combine the beams of two beam generators at an appropriate location to form one energy beam. To this end, the laser processing machine may include a beam coupler. The beam coupler can in turn be connected to a beam deflector. Alternatively or additionally, the beam deflector may be movable so that the beam coupler can also be used as a deflector and can supply the energy beam to various laser processing heads. 
         [0029]    In certain implementations, the laser processing machine includes a partition wall that is positioned between two workpiece processing areas such that a workpiece processing operation can be carried out at one side of the partition wall, whilst, at the other side of the partition wall, a workpiece can be loaded or unloaded. If the partition wall is removed, larger workpieces can also be processed. 
         [0030]    Other features and advantages of the invention will be appreciated from the following description of embodiments of the invention with reference to the Figures of the drawings, which illustrate details which are significant to the invention, and from the claims. The individual features can be implemented individually or together in any combination in a variant of the invention. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0031]      FIG. 1  is a plan view of a laser processing machine. 
           [0032]      FIG. 2  is a plan view of a laser processing machine having four laser processing heads. 
           [0033]      FIG. 3  is a schematic plan view of a laser processing machine having a plurality of laser processing heads which are arranged on a sliding member. 
           [0034]      FIGS. 4   a  and  4   b  show a laser processing machine having a beam deflector. 
           [0035]      FIG. 5  shows a laser processing machine having two beam generators. 
           [0036]      FIGS. 6   a  and  6   b  show a laser processing machine having a beam coupling module. 
           [0037]      FIGS. 7   a - 7   c  show a laser processing machine having a beam guiding module. 
           [0038]      FIG. 8  shows a laser processing machine having a partition wall. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]      FIG. 1  illustrates a laser processing machine  10  having a workpiece support  11 A, on which a workpiece  12  is arranged. Alternatively or additionally, the laser processing machine  10  may include one or more workpiece retention members  118  for retaining a workpiece for processing. Above the workpiece  12  a carrier structure  13  is arranged in the form of a portal. The carrier structure  13  can be moved along guides  15 ,  16  in the direction of the double-headed arrow  14 . In this instance, the carrier structure  13  is driven by means of linear drives. The arrangement which brings about the movement in the direction of the double-headed arrow  14  is referred to as a (tool) axis. Laser processing heads  17 ,  18  are arranged at both sides of the carrier structure  13 . These can be moved relative to the carrier structure  13  in the direction of the double-headed arrow  19 . Arrangements which bring about a movement in the direction of the double-headed arrow  19  are also referred to as a (tool) axis. Owing to the fact that laser processing heads  17 ,  18  are arranged at both sides of the carrier structure, a maximum operating range is achieved. In particular, it would be possible to process a workpiece which is substantially as long as the guides  15 ,  16  and whose width almost corresponds to the spacing of the guides  15 ,  16 . 
         [0040]    Around the laser processing machine  10  there are further arranged additional devices, such as an operator console  20 , a switch cabinet  21 , an exhaust  22 , a cooling unit  23 , a power supply  24 , a hydraulic unit  25  and a disc changer  26  for loading and unloading the workpieces. 
         [0041]    In the configuration of a laser processing machine  30  according to  FIG. 2 , a total of four laser processing heads  32  to  35  are provided on the carrier structure  31 , two laser processing heads  32 ,  35  and  33 ,  34  being arranged at each side of the carrier structure  31 , respectively. The laser processing heads  32  to  35  are each arranged on a sliding member  36  to  39 . The sliding members  36  to  39  can be moved in the direction of the double-headed arrows Y 1  and Y 2  and the entire carrier structure  31  in the direction of the double-headed arrow X. This means that an operating range or operating space indicated by the surface-area  40  can be processed by the laser processing machine  30 . The operating range  40  substantially corresponds to the base surface-area  41  of the laser processing machine  30 . Owing to the width of the carrier structure  31 , there is no region produced which corresponds to the width of the carrier structure  31  and in which no processing operation can be carried out. 
         [0042]    The laser processing heads  32  to  35  can either be arranged so as to be fixed in position, for example, centrally on the sliding members  36  to  39 , or they may be located on a small additional axis so that a highly dynamic movement of the laser processing heads  32  to  35  relative to the sliding members  36  to  39  is possible. 
         [0043]    In the laser processing machine  50  according to  FIG. 3 , two laser processing heads  55  to  62  are provided on each sliding member  51  to  54 , respectively. The laser processing heads  55  to  62  can be arranged so as to be fixed in position on the sliding members  51  to  54  or be arranged so as to be able to be moved on the sliding members in a coupled state or independently of each other. The operating range is indicated with the reference numeral  63  and the base surface-area of the laser processing machine  50  with the reference numeral  64 . 
         [0044]      FIGS. 4   a  and  4   b  schematically illustrate the power switching between two laser processing heads  55 ,  66 . In a beam generator  67 , a beam is produced and supplied via a beam deflector  68  to the laser processing head  65  ( FIG. 4   a ) or the laser processing head  66  ( FIG. 4   b ). During the processing of a workpiece, it is therefore possible to switch from the laser processing head  65  to the laser processing head  66  at the appropriate location. To this end, the beam deflector  68  can be movably arranged and controlled by a control device. 
         [0045]    As illustrated in  FIG. 5 , however, there may also be provision for a plurality of beam generators  69 ,  70  to be provided which each co-operate with an associated laser processing head  71 ,  72 . 
         [0046]    However, as can be seen in  FIGS. 6   a  and  6   b , there is also another possibility for adjusting the power when a plurality of beam generators  73 ,  74  are used. The beams of the beam generators  73 ,  74  can be directed onto a beam coupling module  75  where the laser power is at least partially added together and subsequently transferred to one of the laser processing heads  76 ,  77 . The beam coupling module  75  can be movably arranged so that the laser power can be selectively transmitted to the laser processing head  76  ( FIG. 6   a ) or  77  ( FIG. 6   b ). Owing to the beam coupling module  75 , it is optionally also possible to transmit only part of the coupled power to the laser processing heads  76 ,  77 . 
         [0047]    According to the configuration illustrated in  FIGS. 7   a  to  7   c , laser power can be produced using a beam generator  80  and transferred via a beam splitter module  81  to a first laser processing head  82  or a second laser processing head  83 . In  FIGS. 7   a  and  7   b , the beam splitter module is passive. This means that the laser power of the beam generator  80  is transferred either to the laser processing head  82  ( FIG. 7   a ) or to the laser processing head  83  ( FIG. 7   b ). In  FIG. 7   c , the beam splitter module is active. This means that the laser power of the beam generator  80  is divided and a part of the laser power produced can be transferred to both laser processing heads  82 ,  83 . 
         [0048]      FIGS. 4 to 7  illustrate various beam guiding possibilities. This was illustrated by way of example by means of two opposing laser processing heads on a carrier structure. It will be appreciated that these concepts can also be transferred to a plurality of opposing laser processing heads on a carrier structure. Furthermore, it is conceivable to use the beam guiding concepts on two or more laser processing heads which are located at the same side of a carrier structure. 
         [0049]      FIG. 8  illustrates a configuration of a laser processing machine  90  which has a partition wall  91 . When the partition wall  91  is used, it is thereby possible to carry out a workpiece processing operation at one side  92  and to load or unload a workpiece  94  at the other side  93 . Since the carrier structure with the laser processing head can be moved close to the partition wall from both sides, there is also practically no additional surface-area requirement in this operating mode. When the workpiece processing operation is complete at the right-hand side  92 , the carrier structure  95  can be transferred to the left-hand side  93  so that a workpiece processing operation can be carried out at that location, while the workpiece  96  processed at the right-hand side  92  is removed and a new workpiece loaded. It is also conceivable to omit the partition wall  91  and to process a workpiece which extends at both sides  92 ,  93 . 
         [0050]    A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.