Abstract:
The corresponding machine tool or milling machine for carrying out the method described has a milling spindle which is displaceable in three spatial directions and with which the workpiece can be machined in a machining region, the machine tool or milling machine having at least one mounting slide, with which the workpiece, for the first machining step, can be mounted in gripping adapters. Furthermore, the machine tool or milling machine has at least one rocker, with which the partly machined workpiece can be mounted by means of at least one special gripping adapter in the first, finally machined region of the workpiece for the second machining step.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of the U.S. National Stage designation of co-pending International Patent Application PCT/CH03/00059 filed Jan. 24, 2003, the entire content of which is expressly incorporated herein by reference thereto.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates to a method of machining blanks or pre-machined workpieces from all directions using a machine tool, such as a milling machine for example, to produce components that are finally machined in their three-dimensional shape and to a machine tool, such as a milling machine for example, for carrying out such a method.  
       BACKGROUND OF THE INVENTION  
       [0003]     During the production of turbine blades, work is normally carried out with multi-spindle machining. This means that a blank is first of all subjected to rough pre-machining, then the airfoil region is processed in detail, and then the tip and finally the root are produced. Between these individual machining steps, the workpiece must be reset in each case by hand or by a robot; this is because the milling machines are often only able to carry out individual machining steps, and in particular because each mounting of the workpiece always only allows the machining of a certain region. This type of production is normally referred to as “box production”, since in each case one machine is normally responsible for a certain machining step, and because the workpiece can be temporarily stored in a box after each machining step.  
         [0004]     A problem with such production is, inter alia, the fact that the speed of such a production line is always determined by the speed of the slowest machining step. In addition, the multiplicity of processes for the transfer of workpieces between the individual units, such as milling machines, measuring station, washing station, etc., requires complicated devices and leads to considerable time losses in the production process.  
       SUMMARY OF THE INVENTION  
       [0005]     The invention therefore relates to providing a method and an apparatus for machining a blank from all directions using a single machine tool, such as a milling machine for example, which method makes possible the production of the ready-to-use component in as few machining steps and setups as possible. In this case, the machine tool is able to carry out different operations such as milling, drilling, turning and/or electrical discharge machining, etc. In this context, the expression “milling machine” is therefore to be given a wide interpretation, i.e. it relates to machine tools that are not only able to carry out milling operations but if need be can also carry out turning, drilling, electrical discharge machining, grinding, hardening operations, etc.  
         [0006]     In the present invention, the blank, in a first machining step, is held by at least one gripping adapter and by a first region being given its final partial shape corresponding to the intended use by the machine tool/milling machine, and, in a second machining step, by the partly machined blank then being held by at least one special gripping adapter in the first, finally machined region, and by the remaining region being given its final overall shape corresponding to the intended use by the same machine tool/milling machine.  
         [0007]     The invention consists in mounting the blank in the first step, for the machining, or in fastening it in the machining space of the machine tool or milling machine by means of an adapter, in such a way that that region of the workpiece that is not concealed as a result of the fastening by the adapter or is not inaccessible as a result of the machining by the machine tool or milling machine is already machined in the first machining step into its final three-dimensional shape corresponding to the intended use. Consequently, this enables the workpiece, for further machining, to be fastened by means of a further special gripping adapter that grips the workpiece in certain, already finally machined zones and which is movably mounted on the same base unit of the machine tool or milling machine. Of course, the fastening in this case must take place in such a way that the entire region of the partly machined blank which is still unmachined is accessible in an unrestricted manner for the final further machining by the same machine tool or milling machine. It is thus then possible in the second machining step, on the same machine tool or milling machine, without further resetting, for the partly machined blank to finally be given its overall three-dimensional shape.  
         [0008]     This is quite surprising, for the individual machining steps comprise milling operations and also, inter alia, roughing and finishing, which exert considerable forces on the workpiece and which have hitherto always prevented the person skilled in the art from giving the workpiece its final shape in only two setups on a single machine. Normally, it has always been assumed that the forces produced during the machining lead either to damage to the workpiece or to inadequate quality of the final workpiece (e.g. as a result of vibrations, moments, etc.). However, it has been found that it is possible, in a first machining step, to already give functional surfaces their final shape and to immediately use precisely these functional surfaces for the mounting for the second machining step, and to carry out the second machining step using the same machine tool or milling machine.  
         [0009]     The reduction in setups and the use of only one machine tool or milling machine leads to a considerable simplification in the production process and to cost savings (less downtime, fewer means for the transfer of components, fewer milling machines, etc.) and nonetheless permits the production of final shapes which meet the highest quality requirements. The direct transfer from the adapter for the first machining step to the special gripping adapter for the second machining step without the use of a robot permits, in an especially simple, defined manner, the transfer from one setup to the next, which leads to a reduction in the requisite adjustments. In this context, “defined manner” means that the means for removing the partly machined workpiece, i.e. the special gripping adapters, grip this workpiece at a well-defined location, so that the partly machined workpiece can then be finish-machined in a likewise well-defined position in the second machining step. The effective configuration of the special gripping adapter (spacing and type of mounting points) therefore depends as a rule on the contour of the partly machined region of the workpiece.  
         [0010]     The overall shape which is in accordance with the intended use and which can be achieved with the method according to the invention involves any desired component which can be obtained from a blank by the abovementioned operations. The method is especially suitable for the production of components as used in a turbine (steam turbine or gas turbine). Thus the component is preferably a moving or guide blade of a turbine.  
         [0011]     According to a first preferred embodiment of the invention, the blank is a blank made of metal or a ceramic material in the form of a rectangular or cylindrical or polyhedral, in particular preferably parallelepiped-shaped, block or is a cast blank or forged blank. It is likewise possible to feed the blank to the method according to the invention in an already pre-machined form. Surprisingly, the method according to the invention is also successful with such difficult-to-machine components, and this without loss of quality of the final shaped parts.  
         [0012]     According to a further preferred embodiment of the invention, the partial shape is a shape leaving unmachined projecting portions at the tip part and at the root part, recesses being provided between the projecting portions and the partial shape in particular preferably during the first machining step. The proposed method proves to be suitable, for example, for producing guide or moving blades or turbine blades, the partial shape in this case involving the tip of the blade, the airfoil region of the blade and the root of the blade, and projecting portions gripped by the gripping adapter being left at the tip and at the root after the first machining step, these projecting portions then being removed in the second machining step.  
         [0013]     According to a further preferred embodiment of the invention, the workpiece, in both machining steps, is machined by a single milling spindle displaceable in three spatial directions (x, y, z) and carrying a rotatable spindle for mounting a cutting tool.  
         [0014]     In particular in the case of large blanks, it proves to be advantageous to provide not only one but two gripping adapters, between which the workpiece is clamped in place. Accordingly, according to another preferred embodiment of the invention, the workpiece, in the first machining step, is held in two gripping adapters gripping the blank at the tip and the root, and the first region is processed in the exposed region between the two gripping adapters, the gripping adapters preferably being guided by two mounting slides in such a way that the workpiece, with respect to a milling spindle machining the workpiece, can be displaced along a first axis and rotated about this first axis. The rotatability of the workpiece about the first axis has the advantage that the workpiece can also be subjected to a turning operation by the milling spindle. The displaceability along this first axis enables high relative speeds of cutting tool and workpiece while milling spindle and mounting slides are simultaneously displaced in opposite directions, without the workpiece or the cutting tool having to be displaced on its own at correspondingly higher speed.  
         [0015]     With regard to the rotatability about this first axis, this rotatability can in particular preferably be configured for the two gripping adapters independently of one another. This means that the two gripping adapters on the mounting slides can be activated with different speeds and in opposite directions or in the same direction. The advantage of such independent rotatability of the two gripping adapters, which basically proves to be virtually unexpected, and independently of the present method, is due to the fact that the workpiece, after it has been gripped from both sides by the gripping adapters, can be restrained by slight contra-rotation of the two gripping adapters, which leads to better mounting of the workpiece in the gripping adapters. This restraining state can be recorded electronically and maintained during the entire further first machining step, or else if need be can also be corrected subsequently or increased. The torsion accordingly applied to the workpiece can be taken into account and corrected in the program for the electronic control of the milling spindle.  
         [0016]     In order to also permit in a simple manner the second machining step in the same machine tool or milling machine while using the same milling spindle, according to a further exemplary embodiment of the present invention, after the first machining step with the milling spindle, the partly machined blank is automatically gripped by at least one special gripping adapter in the first, finally machined region, that is to say no robot is required for the resetting. The at least one gripping adapter is then released and moved out of the working region of the milling spindle in order not to get in the way during the second machining step. The partly machined blank, while being mounted in the special gripping adapter, is then given its final overall shape corresponding to the intended use by means of the same milling spindle, i.e. the projecting portions which had served for mounting in the adapters during the first machining step are now removed in the second machining step and, for example in the case of a turbine blade, the tip and root parts are given the final shape. In this case, it proves to be advantageous to fasten the at least one special gripping adapter to at least one rocker which is rotatable about a second axis and which in turn is arranged on a rocker slide unit, which is displaceable along a third axis and is mounted so as to be rotatable about this third axis, the rocker if need be also being displaceable perpendicularly to this third axis. A rocker of such a design, on the one hand, permits the direct automated resetting from the adapter for the first machining step to the special gripping adapter for the second machining step, and, on the other hand, due to its movability, it enables the second machining step to be carried out by the same milling spindle, since the rocker is able to mount the partly machined workpiece in a movable manner in the machining region of the milling spindle. The intermediate step normally present—the transfer of the workpiece by means of a robot from one mounting into a second—is thus completely dispensed with. As is already the case with the mounting in the adapters during the first machining step, the rotatability of the rocker about the second axis, while using two rockers, can also be adjustable independently of one another in an advantageous manner, so that, for the second machining step too, the workpiece can be restrained and effectively fixed by slight contra-rotation of the two rockers relative to one another.  
         [0017]     According to another preferred embodiment of the invention, the final overall shape can be cleaned and/or measured after the first and/or the second machining step and/or can be packed after the second machining step. The corresponding means for carrying out these steps, which in addition may also comprise the provision of a material or component material code, can be either carried out on the same machine tool or milling machine or else can be realized in a downstream step on other units. It is likewise possible, before the machining, to channel the blank through a material-code-reading station, which can be designed either separately or as part of the machine tool or milling machine. This material-code-reading station serves to assign a certain NC program for controlling the machining process.  
         [0018]     The present invention proves to be especially suitable for the production of guide or moving blades or of turbine blades with or without shroud band. In particular in the production of large components of this kind having a surface within the range of N4 to N5 at tolerances of +/−0.002 mm, a length within a range of 120 to 2400 mm with a rotating diameter of 50 to 400 mm and a weight of 10 to 400 kg, the present method can be used in a single machine tool or milling machine without stability problems (despite large moment arms) or accessibility problems for the machining head occurring in the process.  
         [0019]     Further preferred embodiments of the method according to the invention are described in the dependent claims.  
         [0020]     As already mentioned at the beginning, the present invention also relates to a machine tool or milling machine for carrying out the method as described above. This machine tool or milling machine is characterized in that it has a milling spindle which is displaceable in three spatial directions and with which the workpiece can be machined in a machining region, in that the machine tool or milling machine has at least one mounting slide, with which the workpiece, for the first machining step, can be mounted in gripping adapters, and in that, furthermore, the machine tool or milling machine has at least one rocker, with which the partly machined workpiece can be mounted by means of at least one special gripping adapter in the first, finally machined region of the workpiece for the second machining step. In this case, the milling spindle is advantageously arranged on the one side of the mounting slides, whereas the rocker is advantageously arranged on the other side of the mounting slides. Thus, the at least one mounting slide, during the machining with mounting in the rocker in the second machining step, can be moved in a simple manner out of the machining region of the milling spindle.  
         [0021]     In this case, the milling spindle typically has a base slide unit displaceable in the X direction on rear guideways arranged on the base frame, a Y slide unit displaceable on this base slide unit in the Y direction, and a Z slide unit displaceable on the Y slide unit in the Z direction, and also a UNI spindle rotatable about a rotary axis in the Z slide unit and carrying the cutting tool. In this case, for the machining in particular of blades of the size specified above, it should be possible for the milling spindle to be displaced in the X direction by +/−1000 to 1200 mm and in the Y direction by +/−300 to 350 mm and in the Z direction by +900 to 1000 and −90 to 110 mm, relative to the zero point of the machine arrangement, the UNI spindle in particular preferably being rotatable by +/−90 to 100 degrees about the rotary axis.  
         [0022]     According to another preferred embodiment of the machine tool or milling machine according to the invention, two mounting slides are arranged which hold the workpiece in the first machining step in two gripping adapters gripping the blank at the tip and the root. In this case, the gripping adapters are preferably guided by the two mounting slides in such a way that the workpiece, with respect to the milling spindle machining the workpiece, can be displaced along a first axis and rotated about this first axis, and at the same time the rotation can in particular preferably take place about the first axis of the two gripping adapters independently of one another, synchronously or asynchronously, with different or identical rotational speed. In an especially simple and practical manner, i.e. in a compact manner and with great relative mobility, the displacement axis of the mounting slides is preferably arranged parallel to the X direction of the milling spindle. In order to be able to again machine, in particular, large blades as mentioned above, it should be possible for the mounting slides to be displaced on the base unit along the first axis by in each case+respectively −130 to 170 mm (with regard to the left-hand and right-hand mounting slides, respectively) and by in each case−respectively +1100 to 1600 mm (with regard to the left-hand and right-hand mounting slides, respectively), and the rotation about the first axis should be designed to be endless.  
         [0023]     A further preferred embodiment of the present machine tool or milling machine is characterized in that the at least one special gripping adapter is designed in such a way that it can automatically grip the workpiece partly machined in the gripping adapters, and in that the at least one mounting slide can be displaced out of the machining region of the milling spindle, the at least one special gripping adapter preferably being fastened to at least one rocker which is rotatable about a second axis and which in turn is arranged on a rocker slide unit, which is displaceable along a third axis and is mounted so as to be rotatable about this third axis, the rocker also being displaceable perpendicularly to this third axis. As already mentioned above, the rotatability about the second axis in the presence of two rockers is advantageously designed independently of one another, so that the workpiece can also be restrained for the second machining step by slight contra-rotation. With regard to the arrangement of the axis relative to one another, it may be mentioned that the second axis of the rocker is advantageously arranged parallel to the X direction of the milling spindle and/or that the third axis is arranged parallel to the X direction of the milling spindle. In order to be able to machine, for example, large blades as mentioned above, the rocker should be rotatable about the second axis by +/−50 to 60 degrees, the rocker slide units should be displaceable along the third axis by +respectively −1200 to 1800 mm and by −respectively +80 to 120 mm (with regard to the left-hand and right-hand rocker slide units, respectively) and should be rotatable about this axis by +50 to 60 degrees, and the rocker should be displaceable perpendicularly to the third axis by −50 to 60 mm respectively +140 to 150 mm.  
         [0024]     Further preferred embodiments of the machine tool or milling machine according to the invention are described in the dependent patent claims.  
         [0025]     The present invention also relates to the use of an apparatus or a method as described above for producing a guide or moving blade or a turbine blade, in particular a turbine blade with or without a shroud band, having a surface within the range of N4 to N5 with tolerances of +/−0.002 mm, a length within the range of 120 to 2400 mm, with a rotating diameter of 50 to 400 mm, and a weight of 10 to 400 kg. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     The invention is to be explained in more detail below with reference to exemplary embodiments and in connection with the figures. In the drawing:  
         [0027]      FIG. 1  shows a milling machine with 21 axes in a perspective view;  
         [0028]      FIG. 2  shows a further view of the milling machine according to  FIG. 1  with the rockers shown in detail;  
         [0029]      FIG. 3  shows a detailed view of the milling machine according to  FIG. 1  of the machining region with a workpiece (turbine blade with special adapter for cast or forged blades) clamped in place in mounting slides;  
         [0030]      FIG. 4  shows a view of the milling machine according to  FIG. 1  with positioning at the machine zero point;  
         [0031]      FIG. 5  shows a view of a blank clamped in place;  
         [0032]      FIG. 6  shows a side view of a partly completed blade clamped in place in the gripping adapter; and  
         [0033]      FIG. 7  shows a side view of a partly completed blade clamped in place on the NC rocker. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]      FIGS. 1 and 2  show a blade milling machine in perspective view. The milling machine has a base frame  1  on which the individual elements are mounted. The two guideways  2  for the base slide unit  3  of the UNI milling spindle  7  are provided at a defined angle on the rear side of the base frame  1 . The two guideways  9  for the A-axis slides  11  and  12  are provided in the center region. The guideways  10  for the two rockers  21  are provided at the front. The chip passage  13  is integrated between the guideways  2  and  9 . The chip passage  13  has been transversely ribbed in order to ensure that the frame is not weakened. The Y slide unit  4  of the UNI milling spindle  7 , with which the Y stroke (Y) of the spindle is carried out, is mounted on the base slide unit  3  of the UNI milling spindle  7 , which carries out the X stroke (X) of the spindle. The Z ram  5  is mounted on the Y slide  4  at an angle of 90 degrees to the Y stroke. The spindle carries out the Z stroke (Z) by means of said Z ram  5 . The UNI spindle  7  itself is mounted in a rotary axis  8 , with which it can be swiveled by +/−110 degrees.  
         [0035]     For pure turning work, a fixed tool-mounting system, such as an HSK interface for example, is provided in the flange part of the high-speed spindle. With the two blade rotation axes  16  and  17  of the two mounting slides  11  and  12  about the axes A and C, respectively, the clamped blades can be run in both turning operation and NC operation. They form the two blade rotation axes A and C. To accommodate gripping adapters, these rotation axes are designed with a standard HSK interface. The two blade rotation axes  16  and  17  are mounted on the two rotation linear slides  11  and  12 , by means of which they can perform the linear movements U and V.  
         [0036]     If required, the two NC linear axes U and V can be operated as GANTRY axes. For higher feed rates, the X linear axis of the milling spindle  6  is operated in opposition to the two NC linear axes U and V in order to both halve the acceleration slopes and double the maximum milling speed.  
         [0037]     The UNI motor spindle itself is integrated in a rotary axis  8  and fixed by quick-clamping systems. The energy and signal transmission from the machine to the UNI motor spindle  7  is effected via a “plug-in interface”.  
         [0038]     Mounted on the end face are the two rocker slide units  18  and  19 , which perform the two linear movements X′ and U′. Mounted on said rocker slide units  18  and  19  are the plunger tilting axes B′ and V′, which can tilt the plunger and thus the rocker  21  with their special gripping adapters  22  into the desired position. The two plungers perform the linear movements Z′ and W′ about the correct extension points.  
         [0039]     Mounted on the plungers are the two NC rockers  21 , which perform the rotary and setting movements A′ and C′, respectively.  
         [0040]     Mounted on said NC rockers  21  are the two special gripping adapters  22  which are intended for accommodating the partly finish-milled blades in the finished regions and clamp in a hydraulic manner (cf., in this respect, in particular  FIG. 7 ).  
         [0041]     To change the special gripping adapters  22 , they can each be moved to the right and left toward the end of the base frame into the protected region. Here, exchange can be effected in parallel with the machining time.  
         [0042]      FIG. 3  shows a detail of the machining region of the milling machine when the first machining step is being carried out. Here, it can be seen how the blank is gripped by the two adapters  14  at both ends, using a shaped gripping adapter, and how as far as possible the entire region arranged between the two holding points is machined via the cutting tool  25 .  
         [0043]      FIG. 4  shows the position of the machine at the machine zero point, relative to which the following deflections of the individual slides and units are provided. This for two different types of machine—a small variant (HSTM800) and a large variant (HSTM2000).  
         [0044]     In this case, the values for the main axes are as follows:  
                                                                                     Axis       HSTM800   HSTM2000                                        X   +/−1050   mm   +/−1200   mm           Y   +/−310   mm   +/−310   mm           Z   +910   mm   +910   mm               −100   mm   −100   mm           U   +150   mm   +150   mm               −1100   mm   −1550   mm           V   −150   mm   −150   mm               +1100   mm   +1550   mm           A/C   endless       endless           B   +/−95   degrees   +/−95   degrees                      
 
         [0045]     The values for the superimposed device with the rockers  21  are as follows:  
                                                                                     Axis       HSTM800   HSTM2000                                        Left-hand rocker                           X′   +1260   mm   +1700   mm               −100   mm   −100   mm           Z′   −55   mm   −55   mm               +145   mm   +145   mm           B′   0       0               +50   degrees   +50   degrees           A′   +/−55   degrees   +/−55   degrees           Right-hand rocker           U′   −1260   mm   −1700   mm               +100   mm   +100   mm           W′   −55   mm   −55   mm               +145   mm   +145   mm           V′   0       0               +50   degrees   +50   degrees           C′   +/−55   degrees   +/−55   degrees                      
 
         [0046]     For the displacement dimensions specified above, such a milling machine has a size of 6×9×4.5 m.  
         [0047]     The method of machining a blank from all directions using a machine as has just been described above is now to be shown. In this case, by way of example, the overall shape to be achieved involves a turbine blade. Here, FIGS.  5  to  7  show individual sections of the production method.  
         [0048]     The following shapes and materials are used as raw material: bars (rectangular shape, round or any other desired cross section), forged or cast blanks, provided with material code for quality assurance (digits, letter code laser-cut, punched or rotationally stamped).  
         [0049]     In this case, the overall shape to be achieved has the following qualities:  
                                                               Blade qualities:   surface   N4-N5                   tolerances   ±0.002   mm           Sizes:   length   &gt;120   mm                   &lt;2400   mm               rotating diameter   &gt;50   mm                   &lt;800   mm               weight   &gt;10   kg                   &lt;400   kg                      
 
         [0050]     To this end, a blank  32  of any desired shape is brought manually and/or by means of a handling system into the blade milling machine, which may also be in a flexible cell, and is brought out again by the same transport systems after the machining. In this case, the method is to be demonstrated with the aid of two different blanks; on the one hand using a blank  32  in the form of a raw material bar (point  1  of the sequence of method steps specified below), and on the other hand using a blank  32  in the form of a cast or forged blade (point  2  of the sequence of method steps specified below). When a raw material bar is used, it is clamped directly in place by means of a robot, whereas in the case of complex parts, such as cast or forged blades for example, the blank  32  is preferably first of all clamped in place in an adapter, and then the blank together with the adapter is inserted into the machine by means of a robot. The actual machining of such a blank  32  is then described with reference to point  3 .  
         [0051]     1) Blank  32  in the form of a raw material bar 
        1.1) The raw material bar is placed on a loading belt or ramp, with which it passes to the handling system at a transfer location.     1.2) Here, the raw material bar is oriented for the defined transfer.     1.3) Here, the raw material bar is clamped with a gripper and is brought to a material-code-reading station by means of the handling system.     1.4) The material code is read and signaled to the production control system.     1.5) In this way, the raw material bar is recorded in a clearly defined manner and assigned a production number.     1.6) After that, the raw material bar is transported to the milling machine (HSTM) by means of the handling system.     1.7) The raw material bar is then brought into the machine to the transfer or gripping position between the two A axes (NC rotation axes  16  and  17 ).     1.8) By traverse of the handling system in the direction of the A axis  16  or  17  and/or by the traverse of the two NC linear axes  11 ,  12 , on which the axes  16 ,  17  are mounted, the raw material bar passes into the raw-material-bar gripping adapters or adapter  14 . After the gripping of the raw-material-bar gripping adapter  14  (accurate positioning, e.g. via a stop  31  and fixing via clamping jaws  30 ), the handling system leaves the machine working space and assumes other tasks in the FMS ( FIGS. 5 and 6 ).     1.10) The actual production steps (item 3 further below) start.        
 
         [0061]     2) Blank  32  in the form of a cast or forged blade 
        2.1) In the case of the forged and cast blades, a shaped gripping adapter  14  engaging on the root and/or tip of the blade is clamped outside the cell on a specially designated gripping surface on an adjusting and gripping device, on which the blades are centrally oriented. The blade, with shaped gripping adapter  14  on one side or on both sides, is then fed into the pallet station onto a gripping pallet.     2.1) The loaded pallet is then fed into the pallet station.     2.2) To remove a blade (GSS) gripped in the shaped gripping adapters, said blade must be brought to the handling system at the transfer location.     2.3) Here, before removal of the GSS, its material code is read and transmitted to the production control system.     2.4) For further clearly defined identification of this blade, a chip is inscribed by a writing system and is provided in one of the shaped gripping adapters 14.     2.5) In this way, the GSS is recorded in a clearly defined manner and assigned a production number.     2.6) After that, the GSS is gripped by the gripper of the handling system and is brought by the latter to the milling machine (HSTM) (cf., in this respect,  FIG. 3 , in which the gripping adapter  14  is shown as a shaped gripping adapter for a GSS).     2.7) The GSS is then brought into the machine to the transfer or gripping position between the two A axes (NC rotation axes  11 ,  12 ).     2.8) By traverse of the handling system in the direction of an A axis and/or by the traverse of the two NC linear axes  11 ,  12 , the shaped gripping adapters or adapter  14  are/is fixed and clamped in the A axis or axes.     2.9) After the gripping of the shaped gripping adapters  14 , the handling system leaves the machine working space and assumes other tasks in the FMS ( FIGS. 5 and 6 ).     2.10) The actual production steps (item 3 further below) start. 
 
 The blank  32  is now gripped via the two gripping adapters  14  between the two mounting slides  11 ,  12  or, in the case of support on one side, by only one mounting slide, as shown in  FIGS. 5 and 6 . In this case, as can be seen in  FIG. 6 , the center of gravity  35  of the blank, which normally lies on the rotation axis  33  of the mounting slides  11 ,  12 , and the blade rotary center  34  are not usually superimposed. 
       
 
         [0073]     3) Actual production steps in the milling machine 
        3.1) In the first step, during the first machining step in the first setup, all the roughing operations in the rhombus, duct and tip region of the gripped blade, except for a defined allowance for the end contour of the blade, are carried out. This operation can be carried out by conventional milling or by helical roughing. To this end, the roughing tools are clamped in place in the UNI motor spindle  7  by means of an integrated tool changer. The rough milling itself is effected by means of an NC program.     3.2) In the second step, during the first machining step, using the “semi-finishing tools”, the already clamped, rough-milled blade is given a constant allowance (plus 0.2 to 1.2 mm) relative to the final contour by spiral (helical) and linear milling. The allowance is dependent on the type of blade. In various blade types, this step 3.2 may also be omitted.     3.3) In the third step, during the first machining step, using the “finishing tools”, the complete blade channel is given the desired contour and surface quality by spiral milling (helical milling).     3.4) In the fourth step, during the first machining step, the rhombic surfaces at the tip and root, including the blade-suspension and sealing parts, are then produced, i.e. the functional surfaces of the root geometry (H root, etc.) are already produced in this step.     3.5) After that, still in the first setup, the turbine blade is measured by means of a position- or contour-measuring system (probe or laser measuring systems). The measuring data are processed for the documentation and, if necessary, correction data are prepared for the next turbine blade production and are transmitted to the controller and to the control system for including in the corresponding NC program.        
 
         [0079]     After this operation, the blade is finished except for the two end faces at the tip and root and the first machining step has been completed. 
        3.6) In order to be able to machine these two end faces, the rhombic position of the blade is brought by the two A rotation axes  16 ,  17  and linear axes U, V into a defined transfer position (rotary angle of the A axis). 
            For the transfer itself, the two rockers  21  are brought into this position on the front side of the milling machine. After that, the rockers  21  (cf.  FIG. 7 ) are swung in by their swivel axes B′ and V′, respectively, and are then extended toward the machine center. Attached to this plunger is a special gripping device  22 , with which the blade is then hydraulically gripped in special gripping and locating jaws.     For the precise positioning, the special gripping device  22  can be additionally positioned by an NC tilting axis A′ or C′, respectively. For the different blade geometries, the special gripping and locating jaws  14  are exchanged outside the working space on the right and left at the front side of the machine in parallel with the machining time. Furthermore, the gripping stroke can be increased by exchanging the extended hydraulic cylinder.    
            3.7) Once the blades are then clamped in the two special gripping devices  22 , the two shaped gripping adapters  14  are released and the A axes  11 ,  12  are brought to the right and left on the outside into “parking positions”. This is necessary in order to avoid a subsequent collision with the milling spindle  7  and with the axes Y, Z and B.     3.8) For the actual machining of the end faces of the root and tip, especially in the case of long blades, the two rockers  21  are moved to the right or left in order to obtain sufficient clearance space for the UNI spindle  7 , etc.     3.9) By introducing the requisite tools as replacements into the UNI spindle  7 , these two faces are then finish-milled, if need be, by rotating the B axis of the motor spindle through 90 degrees.     3.10) The position may be checked if required.     3.11) After the flushing process, which removes all the contaminants from the blade, one or more position- or contour-measuring systems (probe or laser measuring systems) are clamped in place in the UNI motor spindle  7 . Furthermore, a surface-quality measuring system can be exchanged here. The blade is then measured with these devices. The measuring data are processed in the operating computer in order to be able to carry out, if appropriate, correction machining. Furthermore, the quality documentation is prepared here.     The second machining step in the second setup has thus been completed.     3.12) The blade is then tilted toward the handling system by lifting the rocker  21  to the transfer station.     3.13) After that, the blade, by means of the same handling system, if need be after previous gripper exchange, is brought to the inscription station in order to provide it with a clearly defined code (usually a numerical code) here.     3.14) After this inscription, the blade passes into the washing and preserving machine, from which it is then discharged. 
 
 List of Designations 
       
 
         [0092]      1  Base frame  
         [0093]      2  Rear guideways  
         [0094]      3  Base slide unit (X direction of the milling spindle)  
         [0095]      4  Y slide unit of the milling spindle  
         [0096]      5  Z slide unit of the milling spindle  
         [0097]      6  Milling spindle  
         [0098]      7  UNI spindle  
         [0099]      8  Rotary axis of  7   
         [0100]      9  Guideways for the mounting slides  
         [0101]      10  Guideways for the two rockers  
         [0102]      11  Left-hand mounting slide  
         [0103]      12  Right-hand mounting slide  
         [0104]      13  Chip passage  
         [0105]      14  Gripping adapter  
         [0106]      15  Workpiece  
         [0107]      16  Left-hand blade rotation axis  
         [0108]      17  Right-hand blade rotation axis  
         [0109]      18  Left-hand rocker slide unit  
         [0110]      19  Right-hand rocker slide unit  
         [0111]      20  Rotary guide  
         [0112]      21  NC rocker  
         [0113]      22  Special gripping adapter  
         [0114]      23  Gripping arm of  22   
         [0115]      24  Adjusting cylinder for  21   
         [0116]      25  Cutting tool  
         [0117]      26  Tip of the blade  
         [0118]      27  Airfoil region of the blade  
         [0119]      28  Root of the blade  
         [0120]      30  Clamping jaw of  14   
         [0121]      31  Stop for blank  
         [0122]      32  Blank  
         [0123]      33  A axis and C axis, respectively, of mounting slides  
         [0124]      34  Blade rotary center  
         [0125]      35  Center of gravity of the blank  
         [0126]      36  Flat material, projecting portion  
         [0127]      37  Guide cylinder of  21   
         [0128]      38  Rotation axis of  21  (A′ or C′ axis)  
         [0129]      39  Adjusting cylinder of  23   
         [0130]      40  Contour line of the blank  
         [0131]      41  Fixing lugs of  22