Machine tool

p0001The invention relates to a machine tool according to the preamble of Claim first

p0002Such machine tool is made of <patcit id="pcit0001" dnum="JP4365529A"><text>JP 4-365529 A</text></patcit> known.

p0003A machine tool of a machine frame, one on the machine frame arranged workpiece holder for a workpiece to be machined, one at the machine frame movably arranged tool spindle for receiving a tool, a first tool spindle supporting carriage which along a first axis is comprising movable and is guided on a first carriage support, a along a second, transverse to the first axis extending axis movable and comprising the first carriage support second carriage, which at a second, as a second center aperture surrounding yoke formed slide carrier is guided, wherein the second carriage support is part of the machine frame, and a first and a second drive for carrying out a relative movement between the tool and the workpiece in the direction of the axes of the <patcit id="pcit0002" dnum="US4987668A"><text>US 4,987,668</text></patcit> known, at which the second carriage forms a closed portal carrier, on whose two columns, the first slide carrier is guided.

p0004The invention has the object to improve a machine tool of the generic type such that it has a stable construction as possible and can be achieved the highest possible dynamics.

p0005This object is achieved in a machine tool of the type described above according to the invention with the characterizing features of claim. 1

p0006The advantage of the invention can thus be seen that this is a stable and rigid construction for positioning the tool spindle available.

p0007A very high dynamics of movement of the tool spindle can be achieved if at least the first drive and the second drive two aligned parallel to the respective axis, spaced in a transverse direction at intervals linear electric motors comprising, when the movable through these linear motors respective slide extends between the two linear motors and if a control is provided which operates the linear motors for moving the respective slide simultaneously.

p0008The inventive concept of using two parallel to the axis aligned linear motors, which are used at the same time to move the slide, a wide dynamic range for driving the carriage is reached, since the usual in rotating spindle drives limitations no longer apply. In addition, the usual in the known spindle drives problems with game, elasticity, friction and wear are eliminated.

p0009Special advantages include the high acceleration and high speeds even long travel and precise positioning.

p0010Additional benefits of using two simultaneously active linear motors, as these give particularly high acceleration forces on a highly dynamic movement of the carriage in a simple manner.

p0011The two linear motors can be operated in different ways.

p0012So, an advantageous solution possibility that the two linear motors are operated together as a single NC axis. Advantageously, this separate power supplies are provided, however, despite the common control as an NC axis. This possibility can be realized by control technology inexpensive.

p0013Alternatively, it is provided that the two linear motors are controllable as mutually independent NC axes. That is, each of the linear motors having a separate NC axis control system and its own power supply. This has the advantage that the movement of the two linear motors is better matched to one another.

p0014This is particularly advantageous possible if each linear motor is assigned its own measuring system.

p0015In particular, then allowed by active control of the linear motors, a parallel displacement of the slide realized, so that on the one hand act on tours of the carriage substantially no more shear forces which could lead to a tilting of the carriage.

p0016The linear motors can be constructed in different ways. Appropriately, come single-sided linear motors.

p0017In a preferential solution the linear motors comprise parallel to a plane of aligned primary and secondary parts as a linear motor parts.

p0018A particularly compact design when such linear motors can be achieved when the plane in which extend the linear motor parts, transverse to the transverse direction.

p0019In order to dissipate the heat of the linear motors well, it is further advantageous when the linear motors are respectively arranged on both sides in outer regions of the carriage and a carriage support.

p0020Particularly advantageous is the arrangement of the linear motors is, if these are arranged on respective opposite outer sides of the carriage support or the carriage. In this solution, an optimum dissipation of the heat generated by the linear motors into the environment and on the other hand, a compact construction of the carriage or the slide carrier in the direction of the respective axis is possible.

p0021With respect to the guidance of the slide did not provide further details in connection with the explanation of the previous embodiments. For example, it would be conceivable to run the slide on a main guide. It is particularly advantageous, however, in particular in terms of accuracy and the precision of the guidance of the carriage when the carriage of two mutually parallel and extending spaced main guides is performed.

p0022In order to achieve a compact construction and on the other hand - as stated above - the ability to create an optimal cooling of the linear motors, it is advantageously provided that the main guides are arranged between the linear motors.

p0023In this respect the main guides external arrangement of the linear motors could due to the forces acting between the linear motor parts power stability problems.

p0024These stability problems are advantageously achieved in that the respective linear motors are each between a main and an auxiliary guide, the two guides between the carriage and the respective slide support act. The provision of additional guides thus allows a stable guidance of the linear motor parts relative to one another and a sufficient rigidity at the lowest possible mass of carriage and carriage support and thus a high dynamic range.

p0025In order to achieve optimal cooling, it is preferably provided that the linear motors comprise cooled primary and secondary sections.

p0026Such cooling can take place in different ways. Preferably, an embodiment provides that the cooling of the primary and secondary parts through cooling channels in holding elements is performed for the primary and secondary parts, so that these can be cooled by direct contact with the respective holding elements carrying them.

p0027Preferably, the cooling channels are flowed through by a cooling medium which is cooled by a cooling device to a defined temperature.

p0028In connection with the explanation of the previous embodiments was only discussed how an optimum dynamics of the slide is reached. When using electric linear motors both accelerating and braking with these linear motors.

p0029Nevertheless, it is - in particular for safety - advantageous if the slide is additionally fixable by a brake device.

p0030Preferably, the braking device is designed as a mechanically acting brake device. The braking device is used in particular as an automatic braking system which automatically brakes the slide on reaching a predeterminable positions of the carriage.

p0031It is preferably provided that the braking system is actuated by a limit switch, which is thus independent of the control of the linear motors brakes the carriage when it reaches a specified by the limit switch end position and fix.

p0032Alternatively or additionally, it is advantageously provided that the braking device is provided as a failure or Notaussicherung.

p0033Preferably, the braking device is actuated by a switch failure or emergency stop, so that the braking device in case of failure of the electrical power supply for the linear motors or actuation of an emergency stop brakes and sets the carriage.

p0034It is particularly expedient, in particular, very high braking forces effectively apply when the carriage is secured by two in the transverse direction are arranged apart braking devices is. Thus, in particular, the carriage can be effectively slowing, preferably avoid the same when abrupt deceleration.

p0035In an advantageous embodiment of an inventive machine tool is provided that the workpiece carrier is maintained at a in a third direction transverse to the first and second direction movable third carriage.

p0036Preferably, the workpiece carrier is rotatable with a rotary drive relative to the machine frame about an axis, so that the work piece in different rotational positions about a rotational axis can be brought or in a rotary motion - for example in the manner of a spindle - around this axis is displaceable.

p0037A particularly expedient solution provides that the rotary drive is designed as a NC axis so that rotary movements to precisely definable angle or turning operations are feasible.

p0038it is particularly advantageous with respect to the rotary drive if this includes a direct drive, ie no intermediate transmission between a drive motor and the workpiece support is provided.

p0039The advantages of such a direct drive can be seen in the elimination of transmission problems, such as play, friction, etc., and the achievable high dynamics.

p0040In combination with a direct drive, it represents a particularly preferred solution in terms of the achievable accuracy when the rotary actuator is provided with a direct the rotational positions of the workpiece carrier sensing measurement system.

p0041In order to precisely position the workpiece carrier in individual rotational positions and fix can be preferably provided that the rotary drive comprises a braking device, with the fixation of the workpiece holder for machining the workpiece in each rotational position is possible.

p0042is preferably - in particular in an embodiment of the machine tool as a machining center - the rotary drive is constructed as a rotary table, with which the workpiece carrier is rotatable about a vertical axis.

p0043Preferably, the workpiece carrier in a receptacle of the turntable is detachable and can be fixed, so that the workpiece is fixed together with the workpiece carrier on the turntable, and then edited together with the workpiece carrier is transported further.

p0044Preferably, the workpiece carrier is hydraulically clamped in the receptacle of turntable.

p0045Preferably, the workpiece carrier is designed as a pallet on which the workpiece is clamped.

p0046Particularly in the case of a rotatable about a vertical axis rotating table is preferably provided that the rotary table is seated on a carriage which in turn is movable on a slide support comprising a longitudinal bed of the machine frame.

p0047In an advantageous version of a machine tool according to the invention, the second carriage support is seated in the form of a stator on a machine bed.

p0048A third axis which is transverse to the first and the second axis is formed by a longitudinally from the machine bed of a supported longitudinal bed movable carriage. This division of the axes allows an optimum stability and, in particular for linear drives, an optimal distribution of the masses in order to obtain the largest possible dynamic in all axes.

p0049Preferably, the longitudinal bed is covered by the machine bed.

p0050A particularly stable construction results when adjoin the longitudinal bed two Y-shaped legs, the legs being joined at the longitudinal opposite ends of bed with the stand.

p0051In a further embodiment of the invention it is provided that a working space of the machine tool is enclosed by a cell. To allow a highly dynamic movement of the carriage is provided that a boundary of the cell by at least one held on one of the carriages and in its direction of movement extending away from plate is formed, which in all axis positions of the carriage in its direction of extension at least until extends to a limitation of the working space in the direction of extension.

p0052It is particularly advantageous if the boundary of the cell is formed by two extending in opposite directions shields.

p0053It is preferably provided that could be accepted by the first carriage tool engages through a movement gap between the two shields.

p0054In order to cover also this movement gap optimally suited to highly dynamic motion is preferably provided that the latter is also covered, at least in one direction by a movable by the slide plate.

p0055This shield can be performed in any manner. Preferably, this plate is guided on both sides of the movement gap by longitudinal guides.

p0056A particularly advantageous embodiment of a machine tool of the invention provides that two extending in opposite directions shields are provided on the second carriage and the first carriage an extending in a direction sign, while in the other direction, a telescopic cover is arranged and that the shields and the telescopic cover form a boundary of the cell.

p0057As for the structure of the shields have so far been no further information. To achieve good stability, a shield is formed as a lightweight panel comprising a front and a rear position out of sheet metal and in between a voided stiffening body.

p0058Suitably, the stiffening body is a sheet of corrugated tin. but it is also conceivable to carry out this as a honeycomb structure, etc..

p0059Especially advantageous is a solution in which the front and rear sheets are made of aluminum. Better yet, even if the stiffening body is made of aluminum and preferably of the stiffening body and the layers are bonded to each other is.

p0060A further advantageous embodiment has an outside of the cell arranged tool magazine.

p0061Preferably, the tool magazine is designed as a magazine wheel with peripheral toolholders.

p0062To perform a tool change with the tool carrier in a simple manner and as quickly as possible, is provided in the case of a surrounding the working space cell, that a side wall is provided with a swinging door.

p0063Preferably, this swinging door is designed as a double swing door with two door wings.

p0064The door can be opened in any way, because the quickest possible opening of both doors is required for a rapid possible passage through the double swinging door, it is preferably provided that the door can be brought by application of the tool holder in an open position.

p0065To this end, damping elements are preferably provided on the door leaves, which reduce the forces acting on the tool carrier on the door leaf acceleration forces.

p0066In order to bring the door back in the simplest way possible in its closed position and hold in that can is preferably provided that the doors are acted upon by spring elements in the direction of its closed position.

p0067Since in a very rapid opening of the door there is a danger that this open of their position back to neutral by impact against a stop, it is preferably provided that each door leaf is provided with a braking device, preferably in the form of a friction brake device, which of the free mobility door brakes.

p0068Further features and advantages of the inventive solution are the subject matter of the following description and the drawings of several embodiments.

p0069In the drawings:<dl id="dl0001"><dt>Fig. 1</dt><dd>an overall perspective view of a machine tool according to the invention;</dd><dt>FIG. 2</dt><dd>a plan view in the direction of an arrow A in <figref idrefs="f0001">Fig. 1</figref>;</dd><dt>Fig. 3</dt><dd>a plan view in the direction of an arrow B in <figref idrefs="f0001">Fig. 1</figref>;</dd><dt>Fig. 4</dt><dd>a plan view in the direction of an arrow C in <figref idrefs="f0001">Fig. 1</figref>;</dd><dt>Fig. 5</dt><dd>a section through a Z slide with rotary drive axis;</dd><dt>Fig. 6</dt><dd>a perspective view of a second embodiment;</dd><dt>Fig. 7</dt><dd>a partial sectional view taken along lines 7-7 in <figref idrefs="f0006">Fig. 6</figref>;</dd><dt>Fig. 8</dt><dd>a partial sectional view taken along lines 8-8 in <figref idrefs="f0006">Fig. 6</figref> and</dd><dt>Fig. 9</dt><dd>a partial sectional view taken along lines 9-9 in <figref idrefs="f0006">Fig. 6</figref>,</dd></dl>

p0070one in <figref idrefs="f0001">Fig. 1</figref> illustrated first embodiment of a machine tool according to the invention comprises as a whole a machine frame generally designated 10 on which a workpiece 12 is positioned. For machining of the workpiece 12 by means of a tool 14, the tool 14 is accommodated in a tool spindle 16 which in turn is displaceable on the machine frame 10 in an X and Y direction. In addition, the workpiece 12 is still movable in a Z-direction relative to the tool spindle 16 and perpendicular to the X- and Y-axis so that a total of the workpiece 12 and the tool 14 along three mutually perpendicular axes, namely the X, Y - and Z axis for machining the workpiece 12 are movable.

p0071In order to move the tool spindle 16 along the X and Y-axes, the tool spindle 16 is held on a Y-carriage 18 which is in turn to a carriage support 20, formed as a yoke having a central opening 22 in the Y-direction movable. Here, the tool spindle 16 extends with the tool 14 facing away from the rear section 24 (<figref idrefs="f0002">FIG. 2</figref> and <figref idrefs="f0003">Fig. 3</figref>) Through the center opening 22nd The central opening 22 is therefore formed such that the tool spindle 16 along its maximum Y traverse path, determined by the movability of the Y carriage 18 relative to the slide carrier 20 to freely without colliding with edges of central opening 22 is movable.

p0072The slide carrier 20 is of a X-carriage 26 comprises, in turn, is slidably supported along the X-axis on a stand 28th Also, the stator 28 is formed as a yoke and has a central opening 30 out through which the rear part of the tool spindle 24 extending therethrough, the center opening 30 is formed such that the tool spindle 16 in this possible in all positions along the X and Y-axis is moved without collision.

p0073The stator 28 is located as part of the machine frame 10 on a likewise comprised by the machine frame 10 the machine bed 32, which has a longitudinal bed 34, parallel to the Z-axis and thus perpendicular to a plane spanned by the X-axis and Y-axis plane by itself the stator 28 extends away. For a stable connection of the stator 28 with the longitudinal bed 34, the machine base 32 two projecting from the longitudinal bed is Y-shaped legs 36, on which the longitudinal bed 34 remote from ends 38 of the stand sits 28, the ends 38 are below the vertical yoke section 40 of the stator 28 ,

p0074On the longitudinal bed 34 a Z-slide is parallel to the Z-axis 42 is guided, which supports a rotation axis drive 44, with which the workpiece about a B-axis is rotatable.

p0075The rotational axis drive 44, together with a support 46 for a workpiece carrier 48 a designated as a whole with 50 rotary table for the workpiece carrier 48, which is preferably designed as a pallet for receiving the workpiece 12th

p0076The B-axis lies parallel to the plane spanned by the X and Y-axis plane and preferably is perpendicular to a spindle axis 52 of the tool spindle sixteenth

p0077As in <figref idrefs="f0002">FIG. 2</figref> and <figref idrefs="f0003">3</figref> shown, the Y carriage 18 comprises a bridge 70 that supports the tool spindle sixteenth The bridge 70 supports a rear side 72 on guide carriages 74 and 76 which are guided 80 and 82 arranged on a front side 78 of the slide carrier 20 at a distance from each other and extending parallel to the Y-axis guide rails. The carriages 74 and 76 form with the guide rails 80 and 82 first guides 84 and 86 for the Y-slide 80, which are preferably arranged symmetrically to the spindle axis 52nd

p0078On both sides of the main guides 84 and 86, on which the tool spindle 16 opposite sides thereof, a linear motor, respectively 88 and 90 arranged, both of which serve jointly to move the Y carriage 18 in the direction of the Y-axis, and in this case operated simultaneously with one another will.

p0079The two linear motors 88 and 90 are respectively the side of the slide carrier 20 is arranged in such a way that they lie adjacent to a side surface 92 or 94 of the slide support 20 and extending parallel to the Y and parallel to the Z-direction with their winding planes 96th

p0080Each of the linear motors thereby comprises a primary part 98, which is mounted on a support flange 100 of the Y-carriage 18 on one of the side surface 92 and 94, respectively facing side. In this case, the holding flange 100 from an outer end 102 of the bridge 70 extends approximately parallel to the side surface 94, whereby it overlaps this.

p0081facing the primary part 98 a secondary part 106 is arranged on the carriage support 20 by means of a supporting element 104, which is seated on the support member 104 on a side facing the holding flange 100 side, while the supporting member 104 is held on the side face 94th

p0082To support the retention flange 100 against the acting vertically between the primary part 98 and secondary part 106 to the winding plane 96 forces the holding flange 100 on its side remote of the bridge 70 side through an additional guide 108, which one is connected to the retaining flange 100 LM 110 and on the side face 94 seated and comprises parallel to the Y axis extending longitudinal guide 112th This additional guide 108 thus results in the retaining flange 100 in precisely defined orientation to the side surface 94 of the slide carrier 20 and thus the primary part 98 in a defined distance to the secondary part, 106 is either together with the main guides 84 and 86th

p0083For cooling the primary part 98 and secondary part 106 of each of the linear motors 88 and 90 are respectively in the support members for these, i.e. in the retaining flange 100 for the primary part 88 and in the support member 104 for the secondary part 106, cooling channels 114 and 116, provided so that both the primary part 98 and the secondary part 106 by which these each bearing holding member, that is, the retaining flange 100 and the support member 104 can be cooled. The cooling channels 114 and 116 are thereby traversed by a cooling medium which is cooled by a cooling device to a defined temperature.

p0084The driving of the two linear motors 88 and 90 via a respective joint to both linear motors 88 and 90 provided for driving 118, which is a NC-axis control, with, however, separate power supplies 120, said to be traversed by the Y-carriage 18 position along the Y-axis from a superordinate machine control 122 of the control 118 is predetermined.

p0085For detecting the actual position of the Y-carriage, a parallel extending to the Y-axis Y-measuring system 124 is provided, which on the front side 78 of the slide carrier 20, between the tool spindle 16 and of the main guide 86, is seated and a displacement sensor 126, as well as a position sensors 128, wherein the displacement sensor 126 is seated on the slide carrier 20 and the travel sensor 128 is connected to the bridge 70th

p0086The Y-measurement system 124 detects the position of the Y carriage 18 relative to the Y axis and reports them via a line 130 of the control 118, which is thus given an actual Y-position, which for a comparison with the predetermined by the machine control 122 to moving Y-position to a current flowing through a supply line 132 and 134 to the respective linear motor 88 and 90, winding current for the respective linear motor 88 or 90 leads.

p0087To increase the dynamics of the movement of the Y carriage 18 in the direction of the Y-axis acting on the Y-carriage 18 due to the mass of the tool spindle 16 and the Y carriage 18 of gravity is offset by a pneumatic counterbalance 140 which includes a pneumatic cylinder 142 includes, which is held on the slide support 20 and the piston rod 144 at the bridge 70 preferably engages in the area of ​​the tool spindle sixteenth The pneumatic cylinder 142 is pressurized so that it compensates for the force acting on the Y-carriage 18 is substantially gravity, so that 88 and 90 are applied by means of the linear motors in substantially only the acceleration forces.

p0088In order to additionally fix the Y-carriage in defined positions along the Y-axis, is still between the main guide 84 and the tool spindle 16 arranged brake 150 is provided which comprises a brake shoe actuated brake member 152 which is held, in turn, the bridge 70 is and a braking bar 154, which is held on a front side 78 of the slide carrier twentieth

p0089The brake 150 is used for fixing the Y carriage 20 upon actuation of an emergency stop switch or power failure, in the latter case is an automatic activation of the brake 150th

p0090Of the slide support 20 comprising X-carriage 26 is in turn slidably supported on the yoke-shaped rack 28, by means of two main guides 170 and 172, each of which comprises a carriage 174 and a guide rail 176, the guide rail 176 of the to a front face 178 stator 28 is seated, while the carriage 174 is located on a back side 180 of the X slide 26th

p0091The two main guides 170 and 172 are aligned parallel to the X-axis and extend at a distance from each other, preferably in the range of two a carriage support forming crossbeams 184 and 186 of the yoke stand 28th

p0092For driving the X-carriage 26 has two linear motors are provided 190 and 192, the winding plane 194 extends parallel to the X-direction and parallel to the Z-direction. The two linear motors 190 and 192 are also located laterally of the transverse beams 184 and 186, with the lower linear motor 190 below the lower cross beam 184 and the upper linear motor 192 is situated above the upper cross beam 186th

p0093Each of the linear motors 190 and 192 comprises a of a arranged on the X-carriage 26 holding flange 196 borne primary part 198, to which a secondary part 200 is opposite to, in turn, is held by a support member 202 which is disposed on a side surface 204 of crossbeam 184 and 186 , The holding flange 196 also engages over the side face 204 of each crossbar 184 or 186th

p0094To support the retention flange 196 a supplemental guide is also further 206 provided which includes a carriage 208 and a guide rail 210, the carriage 208 on the retaining flange 196 and the guide rail 210 is held on the respective crossbeams 184 and 186th The auxiliary guide 206 also engages on at one of the X-slide 26 remote from the end of each holding flange 196, so that the respective linear motor 190 or 192 is located between the auxiliary guide 206 and the respective main guide 170 and 172 and the primary part 198 opposite the secondary part 200 is supported by the respective auxiliary guide 206 and the respective main guide 170 and 172 on both sides.

p0095in the same manner as described in connection with the linear motors 88 and 90, the retaining flange 196 having cooling channels 212 and the support member 202 are provided with cooling channels 214, which are also passed through the cooling medium which is cooled by the cooling device to a defined temperature.

p0096For the operation of the two linear motors 190 and 192, two control systems 220 and 222 are each provided with these assigned its own power supply for the respective linear motor 190 and 192, the linear motors with electricity the latter via supply lines 224 and 226, 190 and 192, wherein a default carried out the position along the X-axis by the higher-level machine control 122nd

p0097For detecting the exact X-position of the X-slide 26 along the X-axis, two measurement systems are provided 228 and 230, wherein the measurement system 228 is close to the linear motor 190, preferably of the same on the stand 28 facing away from side and the measurement system 230 near the linear motor 192, preferably of the same on the side facing away from the cross beam 186.

p0098Each of the two measuring systems 228 and 230 includes a transducer 232 and a position sensors 234, the transducer 232 is connected to the stator 28 and the position sensors 234 with the X-carriage 26th

p0099The drive 220 for the linear motor 190 is assigned to the measuring system lying close thereto 228, 222 during the driving of the linear motor 192, the measurement system 230 is assigned.

p0100Due to the large distance of the linear motors 190 and 192 in the direction of the Y-axis, and thus also of the large distance between the measuring systems 228 and 230, the assignment of a respective own measurement system to each of the controls 220 and 222 is used, these two drives 220 and 222 completely independently as two separate NC axis control, but also to make work, so that each linear motor 190 and 192, the respective actual measured values ​​of the associated measurement system 228 or 230 anfährt controlled according to the required by the machine control 222 X position. This is an active parallel guidance of the X-slide 26, and so that the parallel alignment of the X-carriage 26 is performed in parallel to the Y axis, accessible, actively controlled to the Y axis.

p0101In order to fix the X-carriage 26 in positions along the X-axis of each of which a brake body 254 having the brake shoes and a braking bar 256, two brakes are additionally provided 250 and 252, wherein the braking bar 256 of the brake 250 at the cross-beam 184 and the brake bar brake 252 on the crossbar 186 are held while the braking members 254 of the two brakes 250 and 252 sit in the back 180 of the X slide 26th

p0102Both brakes 250 and 252 are provided for fixing the X-slide upon actuation of an emergency stop switch or power failure.

p0103The longitudinal bed 34 comprises two spaced apart and parallel to the Z axis extending stringers 290 and 292, which form a slide carrier and 294 and 296 carry the main guides for the Z slide 42nd Each of the main guides each comprise a resting on the supporting beams 290 and 292, guide rail 298 and a movable on the guide rail 298 LM 300, which is held on the Z slide 42nd

p0104The Z-slide 42 includes a housing 302 of the rotational axis drive 44 to which a rotor designated as a whole by 304 by means of a rotary bearing 306 is mounted for rotation about the B-axis.

p0105The rotor 306 is directly driven by a motor designated as a whole with 308, the stator is supported 310 in the housing 302 and the rotor part 312 is rotatably seated on the rotor, wherein the stator 310 and the rotor part 312 between the pivot 306 and the carriage 300 in the housing arranged 302nd

p0106For detecting the rotational positions of the rotor 304 relative to the housing 302, a rotary encoder is radially inside of the motor 308 disposed 314, this encoder 314 reports the actual rotational position of the rotor 304 relative to the housing 302, a drive 316, which in turn via a supply line to the motor 308 with power supplied, so that the rotational movements can be carried out as an NC-controlled B-axis movements.

p0107The individual rotational positions of the motor 308 are specified via the machine control 122 of the rotational axis control 316th

p0108In order to fix the workpiece carrier, the receptacle 46 provided on the rotor 304, which are arranged spaced apart roller bearings 320 having which support the workpiece carrier on a bottom 322nd Further, the roller bearings engage 320 in the slots 324 of the workpiece carrier, so that the workpiece carrier in the direction of the housing 302 also in this direction and acted on pads 326 on the rotor 304 can be mounted by moving the recording 46th These pads 326 serve for centering and exact orientation of the tool holder 48 relative to the rotor 304 about an exact positioning of the workpiece holder 48 thus to achieve relative to the rotor 304 and with respect to the B-axis and the Z-axis. Preferably, the pads form 326 extending transversely to the B-axis extending support surfaces and also exhibit more centering pins 330 which engage in corresponding centering bores 332 on the workpiece carrier 48, defined with respect to the B-axis on the rotor 304 to position it.

p0109For displacing the support 46 to the housing 302 toward or away from a stationary to the housing 302 holding shaft 334 is a shell of the rotor 304 is provided, on which a Covered by the rotor 304 cylinder 336 to be movable in the direction of the rotation axis or B axis , This cylinder 336 is displaced by application of cylinder chambers 335a or 335b with hydraulic medium and carries the support 46 with the roller bearings 320th

p0110A supply of the cylinder chambers 335a, b takes place in the rotor 304 through a central and by a piston rod of the piston 334 extending stationary feeder 338, the starting extends into the rotor 304 from the housing 302 and the amount of the cylinder chambers 335a and 335b, the cylinder chambers 335a and 335b connects with its hydraulic channels via rotary feeders.

p0111For the fixation of the rotor 304 relative to the housing 302. In addition, a brake is also provided 340 which has a brake member 342 and a brake flange 344, wherein the brake flange 344 is rigidly connected to the rotor 304 and the braking member 342 is firmly seated on the housing 302nd

p0112With the brake 340, the rotational position of the person seated on the workpiece support 48 workpiece 12 for processing by the tool 14 can be fixed.

p0113For the displacement of the Z-slide 42 along the Z-axis of two linear motors 360 and 362 are provided, extending 364 whose coil planes parallel to the Z- and Y-axis in a plane. The two linear motors 360 and 362 lie laterally adjacent to the supporting beam in the region of opposing side surfaces 366 thereof.

p0114Each of the linear motors 360 and 362 includes a primary part 368, which is held on a holding flange 370, wherein the retaining flange 370 is in turn supported on the Z-carriage and the support beam 290 and 292 and extends across the side of the side surfaces of the 366th The primary part 368 opposite a secondary part 372 is arranged, which is in turn sitting on a support member 374 which in turn is held on the respective side surface 366th

p0115Further, 374 cooling channels 371 and 375 are provided, which are flowed through in the same manner as in the X-axis or Y-axis with coolant in the retaining flange 370 and in the supporting element.

p0116In the same manner as in the Y-axis and the X-axis, a support of the retaining flange 370 by a whole with 376 designated supplemental guide, which includes a carriage 378 and a guide rail 380, whereby the guide rail 380 with the respective supporting beams 290 or 292 is connected and the carriage 380 is held rigidly to the holding flange 370th

p0117The acting between the primary part 368 and the secondary part 372 forces are thus taken up in the same manner as the Y axis and the X axis by the respective main guide 294 and 296 and the corresponding additional guidance 376th

p0118To set the Z-slide 42 are also provided in addition brakes 381 and 383, which preferably act between the longitudinal bed 34 and the retaining flanges 370, and are constructed in the same way as the brakes 250 and 252nd

p0119To detect the movement of the Z-slide 42 along the Z-axis of each of the linear motors 360 and 362 is associated with a measuring system 384 or 386, wherein the measuring systems are arranged on an inner side 388 and 390 of the respective support beam 290 and 292, respectively, to as close as possible to lie with the respective linear motor 360 or 362nd

p0120Each of the measuring systems 384 and 386 includes a fixedly connected to the longitudinal bed 34 transducer 392 and an output connected to the Z-slide 42 position sensors 394th

p0121For operation of the two linear motors 360 and 362 each of these is associated with a drive 396 and 398, and each of these controls 396, a distance measuring system 384 and 386 for detecting the actual position in the Z direction. Both controls 396 and 398 is transmitted by the machine controller 122 the position to be moved along the Z-axis, the then compare them with the actual, detected by the measurement systems 384 and 386 positions.

p0122Both controls 396 and 398 operate independently, so that in this way an active parallel orientation of the Z-carriage to the X axis is relatively feasible, exactly as described in connection with the controls 220 and 222nd

p0123In a second embodiment of a machining center according to the invention, shown in <figref idrefs="f0006">Fig. 6</figref>, A working space is, for example, to the solution according to the first embodiment 400, in which a machining of the workpiece takes place 12 by the tool 14, is enclosed by a cell 402 which includes a substantially perpendicular and parallel to the XY plane standing front wall 404, the of the tool spindle 16 is arranged opposite. Between the front wall 404 and the Y carriage 18 of the workpiece support 48 along the Z-axis is moved. The cell 402 further includes two spaced apart side walls 406 and 408, between which the designated as a whole with 42 Z-slide is movable. These side walls 406 and 408 extend from the front wall 404 in the direction of the movable both in Y-direction as well as in X-direction Y-carriage 18 with the tool spindle sixteenth

p0124A front wall 404 opposite the rearward termination of the cell 402 is formed by two held on the X-carriage 26 shields 410 and 412, which for the tool spindle 16 extending from a extending in the Y-direction movement gap 414 respectively in the X direction and to such an extent that they are each on either side and 406 and 408 lie in all X-positions of the X-carriage 26 on the rear side edges 416 and 418 of the side walls or through this in the X direction on a the working chamber 400 opposite side.

p0125The two shields 410 and 412 are rigidly held on the X-carriage 26 via a drawing linkage not shown and form a partial rear end of the cell 402nd

p0126This conclusion is supplemented by the movement gap 414 above the tool spindle 16 closes and trained as a shield top cover 420 and below the tool spindle 16 the movement gap 414 closes lower cover 422nd

p0127The top cover 420 is, as in <figref idrefs="f0007">Fig. 7</figref> illustrated, a held on the Y-carriage 18 plate, which is guided in grooves 424 and 426 of the movement gap 414 bounding and extending in the Y-direction edge strips 428 and the 430th The expansion of the panel 420 is selected so that it 16 is flush with an upper edge 432 in all Y positions of the tool spindle having an upper edge 434 of the blades 410 and 412 or upwards survives this.

p0128In contrast, the lower cover 422, as shown in <figref idrefs="f0007">Fig. 8</figref> shown, a so-called telescopic cover, comprising a plurality of one another telescopically cross übereinanderschiebbaren and cover plates 440, which are guided in a plurality of successively arranged in the Z-direction grooves 442 and 444 of the edge strips 428 and the 430th A top of the cover plates 440 is held on the Z-carriage, while a bottom of the cover 440 is connected with a lower part 450 of the cell 402, wherein the lower part 450 forms a lower termination of the cell 402nd

p0129As in <figref idrefs="f0007">FIGS. 7 and 8</figref> shown that both shields 410 and 412 lightweight panels which two mutually parallel outer layers are 411 and between them and connected with them, preferably glued corrugated inner layer 413 of each thin sheet, preferably aluminum sheet have.

p0130Further, 18 each of the side walls is to feed the working space 40 with a workpiece support 406 and 408 provided with a door 452 and 454, respectively, with the respective door via a transport path 456 is located on the workpiece carrier 48, and at a distance from the Y-carriage 18 is parallel to the X-direction through the cell 402 of a processing position of the workpiece 458 14th

p0131Outside the cell 402 as a whole as 460, designated tool magazine is also arranged, which comprises a rotatable magazine wheel 462 about an axis 464, which axis 462 preferably extends parallel to the spindle axis 52nd That magazine wheel 464 shots 466 are arranged for a variety of tools circumference.

p0132The magazine wheel 464 is arranged such that a transfer position 468 is within the Y / X-traverse of the tool spindle 16, so that the tool spindle 16 with the tool 14 can enter directly into the transfer position 468 due to mobility in the Y / X plane ,

p0133For this purpose, in the rear, adjoining the rear edge 416 portion of the sidewall 406 a in detail in <figref idrefs="f0008">Fig. 9</figref> Double swinging door illustrated 470 is provided which has two parallel to the Z-axis shafts 472 and 474 pivoted on the side wall 406 mounted door leaf 476 or 478 having which have standing in a closed state at a small distance from each other, leading edges 480 and 482, respectively, so that in the closed state of the double swing door 470, the cell 402 is closed. These door panels 476 and 478 are biased by two spring elements 484 and 486, in the direction of its closed position, the closed position is determined by two stops 488 and 490, 492 and 494 create against which the spring elements 484 and 486, two swing arms. The spring element 484 or 486 access preferably on to the pivot arms.

p0134Opening the double swing door 470 is now characterized in that the tool spindle 16 driven in a defined Y-position 496 and is then moved in the X direction against the doors 476 and 478, where the doors 476 and 478 thereof, with damping elements 498 and 500 preferably are provided in the region of their leading edges 480 and 482nd 16 This forces the tool spindle with its outer housing 502 of each door 476 and 478 in an open and<figref idrefs="f0008">Fig. 9</figref> illustrated by dashed lines position, moves into the transfer position 468, passes the tool 14 and takes to rotate the magazine wheel 464 a new tool 14 from the transfer position 468. In the transfer position 468 (shown in phantom) is the tool spindle 16 so that its outer casing 502, door panels 476 and 478 stops in the open position.

p0135Each of the door panel 476 and 478 is additionally provided with a friction brake 504, which comprises an integral with the respective door 476 or 478 friction wheel 506, for its part, to a friction pads 508, which is acted upon by a resilient element 510 against the friction wheel 506 , rests. This is 476 and 478 476 and 478 prevents flash back of the door towards its closed position during rapid opening of both doors, further characterized a slow closing of the door leaf is 476 and 478 ensured.