EP3681671A1

EP3681671A1 - Multi-spindle lathe

Info

Publication number: EP3681671A1
Application number: EP18718785.1A
Authority: EP
Inventors: Dirk Prust; Karl-Heinz Schumacher
Original assignee: Index Werke GmbH and Co KG Hahn and Tessky
Current assignee: Index Werke GmbH and Co KG Hahn and Tessky
Priority date: 2017-09-14
Filing date: 2018-04-16
Publication date: 2020-07-22
Also published as: DE102017121295A1; WO2019052694A1; US20200206822A1

Abstract

The invention relates to a multi-spindle lathe comprising a machine frame, a spindle drum that is mounted on the machine frame such that it can rotate about a spindle drum axis, and workpiece spindles that are respectively arranged in a spindle position on the spindle drum and are mounted such that they can rotate about a workpiece spindle axis in relation to the spindle drum, said spindles being positionable in different spindle stations arranged in a stationary manner in relation to the machine frame, by rotating the spindle drum about the spindle drum axis, for machining workpieces arranged in said workpiece spindles. For plain turning machining, a workpiece guide bushing for guiding a material bar held in the workpiece spindle is associated with each workpiece spindle, and is arranged such that it can move in relation to the respective workpiece spindle in a direction parallel to the workpiece spindle axis.

Description

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MULTISPINDLE LATHE

The invention relates to a multi-spindle turning machine, comprising

Machine frame, a spindle drum rotatably mounted on the machine frame about a spindle drum axis, each in a spindle position on the spindle drum and rotatably mounted about a workpiece spindle axis relative to the spindle drum workpiece spindle units for machining arranged in these workpiece spindles by rotating the spindle drum to the spindle drum axis in

various, relative to the machine frame stationarily arranged spindle positions can be positioned.

Such a multi-spindle turning machine is a classic multi-spindle turning machine.

In such multi-spindle lathes, however, there is the problem to be able to work in the simplest possible way even elongated workpieces without a great design effort is required.

This object is achieved in a multi-spindle turning machine of the type described above according to the invention that each workpiece spindle is assigned a workpiece guide bushing for guiding a held in the workpiece spindle material rod for long turning, which is arranged relative to the respective workpiece spindle in the direction parallel to the workpiece spindle axis movable.

The advantage of the solution according to the invention is the fact that a conventional multi-spindle turning machine can be constructed in a simple manner so that with this by means of the workpiece guide bush a long turning in material rods is possible. - -

In particular, it is possible by the displaceability of the workpiece guide bush, that the workpiece spindles can be arranged immovably relative to the spindle drum in the direction of the workpiece spindle axis, so that there is no need to move the workpiece spindles relative to the spindle drum itself for long turning, and thus in particular a long turning to the system Offenbacher can be done.

With regard to the arrangement of the workpiece guide bushing so far no further details have been made.

It is preferably provided that the workpiece guide bush is guided by means of a foot body to a carrier unit, wherein the carrier unit is arranged in particular in the working space.

In order to be able to realize an exact guidance of the workpiece guide bushing during its movement in the direction parallel to the workpiece spindle axis, a linear guide is preferably for each workpiece guide bushing

provided, which guides the workpiece guide bushing movable in the direction parallel to the workpiece spindle axis.

The linear guide could, for example, be arranged radially outwardly of the workpiece guide bushes with respect to the spindle drum axis.

It is particularly favorable, however, if the linear guide is arranged on a spindle drum axis side facing the respective workpiece guide bushing.

With regard to the design of the linear guide no details were given in connection with the solution described so far. - -

Thus, an advantageous solution provides that each linear guide at least one longitudinal guide and one on the respective at least one longitudinal guide slidably guided and carrying the workpiece guide bushing

Includes slide body.

It is particularly advantageous if the carriage body part of the

Workpiece guide bush holding the base body is.

In principle, it would be conceivable to provide a carrier unit for each of the linear guides.

For structural and space-economic reasons, however, it is particularly advantageous if the linear guides of all workpiece guide bushings are arranged on a common carrier unit.

With regard to the arrangement of the carrier unit, no detailed information has been provided so far.

So it is particularly advantageous if the carrier unit is arranged in a starting from a front side of the spindle drum extending working space of the machine tool.

Preferably, it is provided that the carrier unit extends in the direction parallel to the spindle drum axis.

Preferably, the carrier unit is formed according to the number of workpiece spindles symmetrical to the spindle drum axis.

This means that, for example, with six workpiece spindles of the spindle drum, the carrier unit has a sixfold symmetry to the spindle drum axis and, for example, correspondingly carries six linear guides for the six workpiece guide bushes. - -

In order to maintain the assignment of the workpiece guide bushings to the material rods held in the workpiece spindles even when indexing the spindle drum, it is preferably provided that the carrier unit is rotatable about the spindle drum axis and synchronously with the spindle drum.

This ensures that the assignment of the individual workpiece guide bushings to the individual workpiece spindles is maintained even when the spindle drum is rotated.

This could be done by a specially provided for the carrier unit drive.

In the simplest case, it is provided that the carrier unit is rotatably coupled to the spindle drum.

A structurally particularly expedient solution provides that the carrier unit is mounted on an end face of the spindle drum and is thus carried in particular by the spindle drum.

With this solution, precise positioning of the workpiece guide bushes relative to the workpiece spindles arranged in the spindle drum can be realized in a simple manner during the entire machining process.

Preferably, it is provided in this case that the carrier unit engages in the working space, starting from the end face of the spindle drum.

A particularly expedient solution provides that, starting and in continuation of the carrier unit, a conduit extends further through the working space and escapes from the working space, in particular on a side opposite the end face of the spindle drum, so that lines to the individual workpiece guide bushes are easily made via this conduit can be performed. - -

With regard to the design of the workpiece guide bushes were in

Connection with the previous explanation of the solution according to the invention made no further details.

Thus, an advantageous solution provides that each of the workpiece guide bushings comprises a guide sleeve which guides the material rod coaxially to the workpiece spindle axis and which is freely rotatable relative to an outer housing of the respective workpiece guide bushing.

That is, by such a freely rotatable and the material rod leading, in particular supporting guide sleeve an advantageous

Supporting the material bar can be realized during their processing.

It is particularly advantageous if the workpiece guide bushing acts by means of the guide sleeve with a radial force on the material rod, wherein the radial force is preferably adjustable with respect to the radial force level.

It is particularly advantageous if guide jaws of the workpiece guide bush which can be applied to the material rod are arranged in the guide sleeve which is rotatable coaxially to the workpiece spindle axis and thus one

allow appropriate support and leadership of the material bar.

In order to be able to specify the precision of the guide according to the respective machining, it is preferably provided that each workpiece guide bushing has guide jaws that are movable radially relative to a guide axis of the guide sleeve axis.

In particular, it is advantageous if each workpiece guide bushing acts on the material rod by means of the guide jaws with the radial force. - -

As a result, the radial force can be applied and adjusted in a particularly advantageous manner.

A particularly simple solution provides that the guide jaws are acted upon by a spring in the direction of their voltage applied to the material rod and this leading with a radial force position.

In principle, such guide jaws could be mechanically or electrically adjustable.

A particularly simple solution provides that the guide jaws by means of an adjustment or control unit by a medium, are radially adjustable to thereby be able to adjust the precision of the leadership of the material rod and on the other hand, the ease of movement relative to the material rod.

The medium can serve to counteract a radial force generated by a resilient element in the direction of the material rod to cancel the guide.

Preferably, the medium serves to generate the radial force with which the guide jaws act on the material rod.

In particular, in order to be able to realize the adjustability of the guide of the material rod, it is preferably provided that for each workpiece guide bush a media feed takes place via the foot body of the respective workpiece guide bushing.

In order to be able to realize such a control of the respective workpiece guide bush, it is preferably provided that a line for controlling the respective workpiece guide bushes is guided via the respective foot body. - -

In particular, it is advantageous in this case if a hydraulic feed takes place via the carriage body, for example, to a hydraulic adjusting unit acting on the guide jaws.

In this case, provision is preferably made for hydraulic medium to be guided via a flexible feed line guided to the slide body to the hydraulic feed provided in the slide body, wherein the flexible feed line is able to follow the movements of the slide body parallel to the workpiece spindle axis.

In particular, it is provided in this case that the flexible supply line is guided from a side opposite the end face of the spindle drum side of the working space to the carriage body.

It is particularly favorable if the respective workpiece guide bush can be adjusted by a control unit, in particular a media control unit, with regard to a radial force acting on the material bar for guiding the same.

The medium may be, for example, air or a gas.

A preferred solution provides that the medium is a hydraulic medium, which allows a structurally simple and space-saving feasible and rapid action on the guide jaws.

In the case of actuation of the guide jaws with a medium,

in particular, a medium generating the radial force, a resilient element is expediently provided, which acts on the guide jaws in the direction away from the material rod, to assist in releasing the guide. - -

It is particularly favorable in the inventive solution when the workpiece guide bushings are process-dependent controllable in terms of their radial force, with which they act on the material rod for guiding, so that the precision of the management of the material rod can be controlled process dependent.

In addition, it is preferably provided that the workpiece guide bushings can be fixed by controlling the radial force against movement relative to the material rod in the direction parallel to the respective workpiece spindle axis.

Such a determination of the workpiece guide bushings can be used particularly advantageous when a spindle drum circuit for moving the workpiece spindles from one spindle station to the next and there is a risk that the workpiece guide bushes move relative to the material rod in the direction parallel to the workpiece spindle axis.

A particularly advantageous solution provides that by means of the control unit, in particular the media control unit, the respective radial force is set to a releasing radial force level at which the material rod is freely movable and in particular rotatable relative to the workpiece guide sleeve.

Alternatively or additionally, by means of the control unit, the respective radial force is set to a leading radial force level at which the material rod is supported and guided relative to the workpiece guide bushing and thus to the guide bushing in the direction parallel to the respective workpiece spindle axis, but the guide sleeve through the material rod due to the leading radial force level is driven given friction. - -

Alternatively or additionally, it is further provided that by means of the control unit, the respective radial force is set to a clamping radial force level at which the material rod is clamped in the guide sleeve and thus can not be moved relative to the guide sleeve neither parallel to the respective workpiece spindle axis nor rotated relative to the guide sleeve.

With regard to the possibility that the workpiece guide bushings could shift relative to the material rod when switching the spindle drum, it has proven to be particularly advantageous if a control of the workpiece guide bushings is provided by a machine control, which by moving the spindle drum, the workpiece guide bushings relative to the material rod by increasing fixed the radial force of the guide jaws against movement in the direction parallel to the respective workpiece spindle axis and after completion of the indexing of the spindle drum, the radial force reduced so much that for long turning a displacement of the workpiece guide bushing relative to the material rod while precise support and leadership of the same transverse to the workpiece spindle axis is possible.

Thus, it is possible to select the precision of the leadership of the material bar according to the processing and on the other hand set the workpiece guide bushing relative to the material rod in a spindle circuit.

A particularly favorable solution provides that the machine control changes the speed of the respective workpiece spindle only in the presence of the clamping radial force level, thereby ensuring that the

Guide sleeve also makes the change in the speed of the workpiece spindle. - -

Further, it is preferably provided that the machine control leaves the speed of the respective workpiece spindle unchanged in the presence of the leading radial force level, so that a low friction is sufficient to ensure the entrainment of the guide sleeve of the workpiece guide bushing at the respective speed.

A further advantageous solution provides that the machine control operates the respective workpiece spindle in the presence of the releasing radial force level with respect to its rotational movement at standstill, that is, at the releasing radial force level, the material rod does not rotate, but can be pushed through the stationary guide sleeve of the workpiece guide bushing.

Finally, it is expediently provided that the machine control during the indexing of the spindle drum, the speed of the workpiece spindle adapts to the speed required in the next spindle station, so that the time of indexing the spindle drum can be used to set each new speed, expediently in the indexing the spindle drum, the clamping radial force level is applied and thus inevitably entrainment of the guide sleeve in the speed change.

With regard to the processing of the material bars, no further details have been given so far.

Thus, preferably each spindle station is assigned at least one tool carrier, by means of which a tool held by the latter can be moved both in the X direction transversely to the respective workpiece spindle axis and in the Z direction parallel to the respective workpiece spindle axis.

The tool carriers are preferably arranged stationarily on the machine frame and assigned to the respective spindle stations. - -

In particular, at least a part of the spindle stations are assigned two tool carriers in order to increase the number of tools available for processing in the respective spindle station.

Furthermore, it has not been discussed in detail how the displacement of the workpiece guide bushing should be parallel to the workpiece spindle axis.

In principle, it would be conceivable to associate each shift guide bush with a shift drive.

Such a displacement drive could, for example, an electrical

Displacement drive, for example by means of an adjusting spindle, or rack, or be a pneumatic or a hydraulic displacement drive.

However, to make the solution according to the invention structurally particularly simple, it is preferably provided that the workpiece guide bush is displaceable in the direction parallel to the workpiece spindle axis by the respective tool carrier, which is assigned in particular to respective spindle station.

That is, therefore, no specially assigned to the workpiece guide bushing displacement drive is required, but the displacement of the workpiece guide bushing by means of acting in the respective spindle station at least one tool carrier takes place.

In the case of several, for example, two, a spindle station associated tool carrier is preferably provided that one of the tool carrier is provided to move the workpiece guide bush in the direction of the workpiece spindle axis, while others, for example the other - -

Tool carrier by means of a for controlling the tool carrier

provided machine control the workpiece guide bushing moving tool carrier are subsequently driven and moved, thereby simultaneously a collision of the tools in the processing of the material rod can be prevented.

The displacement of the workpiece guide bushing by means of the tool carrier can be solved particularly easily if the tool carrier is provided with a first driver element for displacing the respective workpiece guide bushing.

The first driver element could act directly on the workpiece guide bush to move it.

However, it has proved to be advantageous if the workpiece guide bushing has a second driver element interacting with the first driver element, so that a displacement of the workpiece guide bushing can be realized by this interaction of the driver elements.

However, when switching the spindle drum and thus also

Moving the workpiece guide bushings with the spindle drum to cancel the coupling of the workpiece guide bushings with the stationary arranged tool carrier and restore, it is preferably provided that the driver elements by movement of the tool carrier in the X direction transverse to the workpiece spindle axis in operative connection or can be brought out of operative connection. - -

This means, for example, that moving the tool carrier in the X direction toward the workpiece spindle axis, in particular initiated by a machine control, establishes the operative connection between the driver elements and movement of the tool carrier in the X direction, in particular initiated by the machine control Workpiece spindle axis away the active connection of the driver elements.

In order to move in at least one spindle station in a simple manner and in particular independently of the tool carriers, the workpiece guide bush, it is preferably provided that a spindle station is associated with a displacement device with which the standing in this workpiece guide bushing.

It is possible to move the workpiece guide bushing in the desired position in this station, without the mobility of a tool carrier in the Z direction must be used for this purpose.

It is particularly favorable if the displacement device comprises a displacement cylinder and a displacement arm and that the workpiece guidance bushing is displaceable with the displacement arm.

In this case, the displacement arm can act directly on any suitable location on the workpiece guide bushing.

It is particularly favorable when the displacement arm acts on a driver element provided on the workpiece guide bushing, for example the abovementioned second driver element.

In principle, such a displacement device could be made to move the workpiece guide bushing into any intended position. - -

The displacement device can be used particularly advantageously if the displacement of the workpiece guide bushing from the respective workpiece spindle head takes place with the displacement device.

In particular, this solution provides that with the displacement device, a displacement of the workpiece guide bush takes place in the maximum position remote from the workpiece spindle head.

Such a displacement is particularly advantageous in the first spindle station in which a feed of the material rod takes place, since in this station the workpiece guide bushing should be displaced into the maximum position remote from the workpiece spindle head simultaneously with the supply of the material rod, in which case a machining the material bar in the first spindle station begins.

In particular, starting from the first spindle station, for example, a displacement of the workpiece guide bushing takes place through a tool carrier assigned to the respective spindle station.

Moreover, the invention relates to a method for operating a multi-spindle turning machine, comprising a machine frame, one on the

Machine frame about a spindle drum axis rotatably mounted spindle drum, each arranged in a spindle position on the spindle drum and rotatably mounted about a workpiece spindle axis relative to the spindle drum workpiece spindles for machining arranged in these workpiece spindles by rotating the spindle drum to the spindle drum axis in different relative to the machine frame stationary arranged spindle stations can be positioned. - -

In such a method, the invention provides that each workpiece spindle is associated with a workpiece guide bush, which is moved in the processing of a material rod as a workpiece in the direction of the workpiece spindle axis, that in each of the workpiece guide bushes, the material rod is guided coaxially to the workpiece spindle axis through a guide sleeve, which is relatively can freely rotate to an outer housing of the workpiece guide bushing.

As a result, in a simple way given the opportunity to perform after the system Offenbacher a long turning in a multi-spindle machine tool.

It is particularly advantageous if the workpiece guide bushes act on the material rod by means of the guide sleeve with a variable radial force.

For example, it is provided for this purpose that in the coaxial with the workpiece spindle axis rotatable guide sleeve, the material rod is guided by this can be applied to guide jaws.

To exercise the radial force, it is expedient if the guide jaws can be adjusted radially to a guide axis of the guide sleeve at each workpiece guide bushing.

Thus, there is expediently the possibility of what the workpiece guide bushings act by means of the guide jaws with the radial force on the material rod.

To generate the radial force is expediently provided that a medium for radial adjustment of the guide jaws is supplied to each workpiece guide bushing. - -

An advantageous possibility provides that the force acting on the material rod for guiding the same radial force is adjusted via a control unit in the respective workpiece guide bush, wherein the control unit is preferably a media control unit, with which a pressure of the medium is adjustable.

It is particularly favorable if, in the case of the workpiece guide bushes according to the invention, the radial force with which they act on the material rod for guiding the same is controlled in a process-dependent manner, so that in each case the radial force can be varied during the machining process and between the machining processes and correspondingly

Requirements of the machining process or between the

Machining process lying activities can be adjusted.

In particular, an advantageous solution provides that the workpiece guide bushings can be fixed by controlling the radial force against movement relative to the material rod in the direction parallel to the respective workpiece spindle axis.

A particularly advantageous solution provides that by means of the control unit, the respective radial force is set to a releasing radial force level at which the material rod is freely movable relative to the guide sleeve and in particular freely rotatable.

Alternatively or additionally, provides a further solution that by means of the control unit, the respective radial force is set to a leading radial force level at which the material rod relative to the workpiece guide bushing in the direction parallel to the respective workpiece spindle axis supported and moved, but the guide sleeve due to the material rod due which is driven by the friction given by the leading radial force level. - -

Alternatively or additionally, provides a further expedient solution that by means of the control unit, the respective radial force is set to a clamping radial force level at which the material rod relative to the guide sleeve neither parallel to the respective workpiece spindle axis

moved still can be rotated relative to the factory guide sleeve.

In particular, it is provided in an advantageous solution that by means of a machine control, in particular under control of the control unit by the machine control, a control of the workpiece guide bushings is provided, which when moving the spindle drum, the workpiece guide bushes relative to the material rod by increasing the radial force of the guide jaws against movement in the direction Fixed parallel to the respective spindle axis and after completion of the indexing of the spindle drum, the radial force so far reduced that for long rotation, a shift of the workpiece guide bushing relative to the material rod while precise support and leadership of the same transverse to the workpiece spindle axis is possible.

A particularly expedient embodiment provides that the speed of the respective workpiece spindle is changed by the machine control only in the presence of the clamping radial force level, thereby ensuring that the guide sleeve always participates in changing the speed of the workpiece spindle and thus the speed of the material rod.

Alternatively or additionally, it is provided that the speed of the respective workpiece spindle is left unchanged by the machine control in the presence of the leading radial force level.

A further expedient solution provides that the respective workpiece spindle is operated by the machine control in the presence of the releasing radial force level with respect to its rotational movement at standstill. - -

Another favorable solution provides that the speed of the workpiece spindle is adjusted by the machine control during the indexing of the spindle drum to the speed required in the next spindle station.

Alternatively or in addition to the previous method features, the invention relates to a method for operating a multi-spindle turning machine, wherein according to the invention each workpiece spindle is associated with a workpiece guide bushing for guiding a held in the workpiece spindle material rod for long turning, relative to the respective workpiece spindle in the direction parallel to the workpiece spindle axis Long turning is postponed. In this case, an advantageous variant provides that each spindle station is assigned at least one tool carrier, by means of which a tool held by this tool is moved both in the X direction transverse to the respective workpiece spindle axis and in the Z direction parallel to the respective workpiece spindle axis.

In particular, there is the possibility that the workpiece guide bushing is displaced by the respective tool carrier in the direction parallel to the respective workpiece spindle axis in order to position the workpiece guide bush so that only the processed one

Projecting sections of the material bar over the workpiece guide bushing.

In particular, in the case of a plurality of tool carriers provided that the workpiece guide bushing is moved with one of the tool carrier, while at least one other tool carrier is subsequently moved by means of a machine control the one tool carrier, so follows its movements. - -

This is worked in particular by the one tool carrier as close to the guide bush and by the at least one tool carrier at a slightly greater distance from the guide bush.

It is particularly favorable if the respective workpiece guide bushing is displaced with a first driver element arranged on the tool carrier.

Furthermore, in addition thereto, it is preferably provided that the workpiece guide bushing is moved by a second driver element cooperating with the driver element.

In order to be able to release and restore the coupling between the tool carrier moving the workpiece guide bush and the workpiece guide bush, it is preferably provided that the respective driver element is brought into operative connection or out of operative engagement by moving the tool carrier in the X direction transversely to the workpiece spindle axis.

Further features and advantages of the invention are the subject of the following description and the drawings of some

Embodiments.

In the drawing show:

Fig. 1 is a perspective view of a working space and in the

Working space arranged units of a first embodiment of a machine tool according to the invention;

Fig. 2 is a central vertical section through a machine frame of

Machine tool with the spindle drum in a cutting plane, which is a spindle drum axis; - -

a horizontal section through the machine frame of the machine tool according to the invention in a sectional plane in which the spindle drum axis is located; a perspective view similar to FIG. 1 without inventively provided workpiece guide bushings with

perspective view of the standing in individual spindle stations workpiece spindles of the spindle drum; a perspective view corresponding to Figure 4 with additionally shown workpiece guide bushes which are arranged upstream of the work space of the workpiece spindles of the spindle drum. a section along line 6-6 in Figure 5 without consideration of tools and tool carriers. a side view in the direction of arrow B in Figure 5, omitting the tool holder. an enlarged section in a cutting plane passing through the spindle drum axis through a carrier unit carrying the workpiece guide bushes and a region of the spindle drum holding the carrier unit; a section in a through the workpiece spindle axis and the spindle drum axis extending cutting plane through a first embodiment of a workpiece guide bushing with a supporting this foot body and a foot body receiving part of the support unit; - -

Fig. 10 is a section through a through the spindle drum axis

extending sectional plane with a sectional representation of the carrier unit and representation of a extending in continuation of the carrier unit through the working space duct;

Fig. 11 is a plan view in the direction of the arrow C in Fig. 10;

Fig. 12 is a plan view in the direction of arrow A in Fig. 1 with tools mounted in the tool carriers;

13 shows a side view of a workpiece guide bush in connection with a tool carrier moving in the direction parallel to the workpiece spindle axis and the carrier unit;

14 shows a perspective illustration of an interaction of a first driver element arranged on a tool carrier with a second driver element arranged on the workpiece guide bushing;

Fig. 15 is a perspective view of the working space of the first

Embodiment arranged tool carrier with the corresponding workpiece guide bushes;

16 is a section along line 16-16 in FIG. 15;

17 shows a perspective enlarged view of a first spindle station of the multi-spindle machine tool according to the invention, in which, at the beginning of the machining operation, a material rod is inserted into the respective workpiece spindle and the material rod is pushed through into the workpiece guide bushing; - -

18 is a schematic simplified representation of the pushing through the

Material rod through the workpiece guide bushing in the first spindle station;

FIG. 19 shows a schematic representation of the processing of the material bar in the first spindle station after passing it through the workpiece guide bushing via a

Machining length BL1;

FIG. 20 shows a schematic representation of the machining of the material bar in the second spindle station in the region of a processing length BL2; FIG.

Fig. 21 is a representation of the processing of the material rod in one

third spindle station over a processing length BL3;

FIG. 22 shows a schematic illustration of a machining of the material rod in a fourth spindle station over a machining length BL4; FIG.

FIG. 23 a schematic representation of the machining of the material bar in a fifth spindle station over a processing length BL5; FIG.

Fig. 24 is a schematic representation of a parting of the machined

Part of the material rod in the sixth spindle station by means of a synchronous spindle;

Fig. 25 is a back side machining of machined in the synchronous spindle

Section of the material bar;

Fig. 26 is a schematic structure of a hydraulic control unit controlled by a machine controller; - -

27 is a flowchart of the processes starting in the first spindle station to the third spindle station with representation of the speed of the workpiece spindles and the pressures for generating the respective radial force level and

Fig. 28 is a section in a through the workpiece spindle axis and the

Spindle drum axis extending cutting plane through a workpiece guide bushing according to a second embodiment of the machine tool according to the invention with a supporting this foot body and the foot body receiving part of the support unit.

An embodiment of a multi-spindle lathe according to the invention shown in FIGS. 1 to 5 comprises a machine frame 10 which has a machine frame base 12 on which a spindle drum housing 14 comprising a front wall 16 and a rear wall 18 is arranged, the spindle drum housing 14 defining a working space 20 of FIG Multi-spindle lathe facing front 22 and a rear side facing away from the working space 20 24, wherein the front wall 16 and the rear wall 18 extend transversely to the machine frame base 12 and upwardly therefrom, and wherein the spindle drum housing 14 is seated with a bottom 26 on the machine frame base 12.

In the spindle drum housing 14 a designated as a whole by 30 spindle drum is mounted, which is rotatable about a spindle drum axis 32 relative to the spindle drum housing 14.

The spindle drum 30 is supported by spindle drum bearings 34 and 36 arranged peripherally on the spindle drum 30, on the front wall 16 or the rear wall 18 which rotatably supports the spindle drum 30 about the spindle drum axis 32, but non-displaceably in the direction of the spindle drum axis 32. - -

In the spindle drum 30, as in particular in FIG. 2 and 3, a plurality of workpiece spindles 40, for example, six workpiece spindles 40, arranged around the spindle drum axis 32 preferably at equal angular intervals and at the same radial distance, so that parallel to the spindle drum axis 32 workpiece spindle axes 42 of the workpiece spindles 40 a constant radial distance from the Spindle drum axis 32 and a constant angular distance from each other.

In particular, the workpiece spindles 40 are held immovably in the spindle drum 30 in the direction parallel to their workpiece spindle axes 42.

As further shown in FIG. 3, each of the workpiece spindles 40 has a workpiece spindle head 44, which faces the working space 20 and lies in the region of a front side 46 of the spindle drum 30, preferably projects beyond it, wherein the front side 46 of the spindle drum 30 likewise faces the working space 20.

Starting from the workpiece spindle head 44, each of the workpiece spindle 40 extends in the direction of its workpiece spindle axis 42 through the spindle drum 30 through to a tensioning drive 50 arranged on a rear side 48 of the spindle drum 30.

Furthermore, each of the workpiece spindles 40 has a spindle tube 52, which is rotatably mounted in the spindle drum 30 and which carries a rotor 54 of a spindle motor designated as a whole 60, the stator 56 of which is arranged stationarily in the spindle drum 30.

The spindle tube 52 carries in the region of the spindle head 44 a clamping device 62 for a workpiece W which can be actuated by the clamping drive 50. - -

In addition, each of the workpiece spindles 40 and each one of the workpiece spindles 40 associated clamping drive 50 has a central passage 64 through which a workpieces forming material rod WS is pushed through, so that a material rod WS is inserted through the clamping drive 50 into the workpiece spindle 40 and can be moved therethrough to the clamping element 62, so that the material rod WS ultimately with a workpiece forming portion for machining over the spindle head 44 projects and through the clamping element 62 for

Machining is fixable.

As shown in Fig. 2 and 3, the spindle drum 30 is rotatable about the spindle drum axis 32 in the spindle drum housing 14, preferably so that the workpiece spindles 40 in defined predetermined spindle stations, for example, the spindle stations Sl to S6 (Fig in a further rotation of the spindle drum 30 in turn in one of

Spindle stations Sl to S6 are, although the respective workpiece spindle 40 is not in the same spindle station Sl to S6 but in another of the spindle stations Sl to S6, for example in the next following spindle shape. For example, an indexing of the spindle drum 30 occurs such that each of the workpiece spindles 40 successively all

Spindle stations Sl to S6 through.

For machining the material rods WS accommodated in the workpiece spindles 40 in the spindle stations S1 to S6, each of the spindle stations S1 to S6 is assigned at least one tool carrier 70 which carries the tools required for turning the workpiece W (FIGS. 2 and 4).

In the illustrated embodiment (FIG. 4) of the multi-spindle turning machine according to the invention according to FIG. 4 are assigned to each of the spindle stations Sl to S5 two such tool carrier 70, which are each arranged in front of a front side 22 of the spindle drum housing 14. - -

Each of the tool carriers 70 (FIG. 2) has, for example, an X-slide 72 which is linearly movable in a displacement direction 74 which extends radially to the workpiece spindle axis 42 of the workpiece spindle 40 in the respective spindle station S 1 to S 6 and thus in each of FIGS Spindle stations Sl to S6 of the respective x-axis corresponds.

For this purpose, an X-displacement drive 76 is provided on the tool carrier 70 (FIG. 2).

Further, as shown for example in FIG. 2, each of these tool carriers 70 is arranged on a quill 80, which passes through the spindle drum housing 14 with a quill axle 82 extending parallel to the spindle drum axis 32, the quill 80 for example in the spindle drum housing 14, for example in the front wall 16 and the rear wall 18 of the spindle drum housing 14, is slidably mounted in the direction of the spindle axis 82, so that the entire tool carrier 70 is movable in a Z-direction relative to the standing in the respective spindle station Sl to S6 workpiece spindle 40 by movement along the spindle axis so that a total of one sitting on the X-carriage 72 tool WZ relative to the material to be machined rod WS in the respective workpiece spindle 40 of the corresponding spindle station Sl to S6 at least in an X direction by the X-slide 72 and in a Z Direction

Moving the entire tool carrier 70 with the sleeve 80 along the sleeve axis 82 is movable.

For displacement of the sleeve 80 along the sleeve axis 82 a designated as a whole with 90 Z-displacement drive is provided, which is a the

Spindle housing 14 passing through the displacement spindle 92, the spindle nut 94 is coupled to the sleeve 80 and sits between the front wall 16 and the rear wall 18 of the spindle drum housing 14. The displacement spindle 92 is further drivable by a Z-drive motor 96 which is arranged on the rear side 24 of the spindle drum housing 14. - -

In order to exploit the existing space in the spindle drum housing 14 for arranging sleeves 80 and Z-displacement drives 90 for an optimal number or a maximum number of tool carriers 70, a designated as a whole with 100 spindle drum drive at a distance from the back 24 of the spindle drum housing 14 and is also arranged at a distance from the rear side 48 of the spindle drum 30, which has a drive housing 102 which is arranged on the machine frame base 12.

In the drive housing 102, a driving wheel 110 is arranged in a central recess 104, which is rotatable about a wheel axle 112 which is arranged coaxially with the spindle drum axis 32.

In this case, the carrier wheel 110 is circumferentially mounted in a carrier wheel bearing 114 of the drive housing 102 and has a arranged in the central recess 104 peripheral teeth 116 for driving the same on.

Further, a gear unit 120 is provided in the drive housing 102, which drives on the one hand via the peripheral teeth 116, the driving wheel 110 and on the other hand by a drum drive motor 130 is driven.

For the rotary drive of the spindle drum 30 by the entraining wheel 110, the entraining wheel 110 is coupled to a drive connecting element designated as a whole by 150, which extends from the entraining wheel 110 to the spindle drum 30 and is connected in a rotationally fixed manner to the spindle drum 30 (FIGS. 2 and 3). ,

In the multi-spindle lathe according to the invention, as shown in FIGS. 1 and 5 to 8, a workpiece guide bushing 160 arranged coaxially to the respective workpiece spindle axis is provided in the working space 20 and in front of the respective workpiece spindle head 44, which is arranged with a foot body 162 on a carrier unit 164 and Direction parallel to the respective workpiece spindle axis 42 is guided (Fig. 5, 6). - -

For this purpose, designated as a whole with 164 carrier unit in turn coaxial with the spindle drum axis 32 for each of the foot 162 a each on both sides by longitudinal guides 166 limited guide channel 172, in which the respective foot 162 is guided by means of a slidably guided on the longitudinal guides 166 slide body 174, wherein the respective carriage body 174 is movable parallel to the respective workpiece spindle axis 42 along the longitudinal guides 166 (FIG. 6).

The longitudinal guides 166 with the guide channel 172 and the carriage body 174 each form a linear guide 168 for the respective workpiece guide bush 160.

Thus, the respective workpiece guide bushing 160 is displaceable relative to the respective workpiece spindle head 44 via a defined displacement region 176 relative to the respective workpiece spindle head 44.

As shown in Fig. 8, for this purpose, the carrier unit 164 is mounted on the front side 46 of the spindle drum 30, preferably by a coaxial with the spindle drum axis 32 arranged support receptacle 182, which extends from the front side 46 into the spindle drum and into which the carrier unit 164 means Fixing 184 engages.

Thus, the carrier unit 164 on the one hand in the direction parallel to the spindle drum axis 32 and on the other hand with respect to a rotational movement relative to the spindle drum axis 32 held firmly on the spindle drum 30 and thus rotatable together with the spindle drum 30 about the spindle drum axis 32, thereby also the workpiece guide bushes 160 in their coaxial alignment with the workpiece spindle axis 42 of the respective workpiece spindle 40 always remain aligned and only in the direction of the respective workpiece spindle axis 42 relative to the corresponding workpiece spindle head 44 are displaced. - -

As shown in FIG. 9, each of the workpiece guide bushes 160 includes an outer housing 192 fixedly connected to the foot body 162 in which a guide sleeve 196 is rotatably supported about a guide sleeve axis 198 by means of a pivot bearing set 194, the guide sleeve axis 198 being coaxial with the respective workpiece spindle axis 42 is.

In the respective guide sleeve 196 is a guide jaw set 202nd

arranged, which radially to the guide sleeve axis 198 movable

Guiding jaws 204 includes, which are radially outwardly provided at their in the direction of the guide sleeve axis 198 at a distance from each other end portions with conical to the guide sleeve axis 198 extending and respectively towards the end of the guide jaws 204 falling down pressure surfaces 206, 208.

The pressure surfaces 206 lie against a complementary conically shaped support surface 212 of a fixed inserted into the guide sleeve 196 support ring 214, while the opposite pressure surfaces 208 at a

complementary conically shaped support surface 216 of a parallel to the guide sleeve axis 198 and slidable within the same annular adjusting piston 218 abut.

The adjusting piston 218 is displaceable parallel to the guide sleeve axis 198 relative to the guide sleeve 196 in the direction of the support ring 214 or away from the support ring 214 to move the guide jaws 204 radially towards the guide sleeve axis 198 at a displacement in the direction of the support ring 214 or at a displacement away from the support ring 214 to allow a movement in the radial direction to the guide sleeve axis 198 of this away, which is in particular supported by a spring 205 which acts on the adjusting piston 218 to bias it in the direction away from the support ring 214. - -

For this purpose, a cylinder chamber 222 is formed between the adjusting piston 218 and the guide sleeve 196, which is connected via a pressure-tight hydraulic rotary feed 224 with a hydraulic channel 226 which passes through the outer housing 192 and the foot 162 and formed in a molded onto the base 162 and continues with this mitbewegbarer feed bar 228 extending from the base 162 in the direction away from the spindle drum 30 in the working space 20.

Insofar as the feed bar 228 projects beyond the carrier unit 164 in the respective position of the workpiece guide bush 160, it runs in a channel 232 enclosed by a channel jacket 234 which, as shown in FIG. 1, starting from the carrier unit 164 through the entire working space 20 extends to one of the front side 22 of the spindle drum housing 14 opposite housing wall 236 of a machine housing 240 of the multi-spindle turning machine.

On a side facing away from the foot body 162 and the housing wall 236 facing end 242 of the feed bar 228, a hydraulic port 244 is provided, which, as shown in Fig. 9 and 10, connects to a hydraulic line 246, which through the channel 232 to a the housing wall 236 held terminal box 248 for the individual to the respective workpiece guide bushes 160 extending hydraulic lines 246 is guided, which are connected in the terminal box 248 with a hydraulic unit 252. - -

Both the hydraulic unit 252 and the channel jacket 234 enclosing the channel 232 rotate with the spindle drum 30 about the spindle drum axis 32, so that the hydraulic lines 246 extending from the supply bars 228 to the hydraulic unit 252 do not experience any torsion but only in the direction parallel to Spindle drum axis 32 and optionally transversely to this are moved in the channel 232, depending on the position of the workpiece guide bushing 160 with the foot body 162 relative to the respective workpiece spindle head 44th

The hydraulic unit 252 is in this case connected to hydraulic supply lines 254, which are guided via a drag chain 256 (FIGS. 10 and 11) which, in one plane perpendicular to the spindle drum axis 32, which coincides with the plane of the drawing in FIG the spindle drum 30 can be wound around the spindle drum axis 32 in such a way that a rotation of the spindle drum 30 about the spindle drum axis 32 is possible so far that the workpiece spindle 40 standing in the spindle station S1 reaches the spindle station S6 and then again a rotation of the spindle drum in the opposite direction of rotation takes place, as described in the guidance of a supply line from the machine control to the individual spindle drums in the context of European Patent Application No. 0 755 316 A.

The hydraulic supply lines 254 are in turn connected to a hydraulic control unit 260 (FIG. 1), which is controllable by a machine control 270 which controls the entire functions of the multi-spindle turning machine.

In the multi-spindle turning machine according to the invention, as shown in FIG. 12, the respective X-slides 72 of the tool carriers 70 are provided with tool holders 282 which position the respective tools WZ such that they are a workpiece on a side of the respective workpiece guide bush 160 facing away from the workpiece spindle head 44 can edit, - -

so that the workpiece in the form of a material rod WS passes through the workpiece spindle 40 and the clamping element 62 of the respective workpiece spindle 40 is stretched, but extends beyond the respective workpiece spindle head 44 through the workpiece guide bushing 160 and in the workpiece guide bushing 160 through the guide jaws 204th is guided, the radial delivery in the direction of the workpiece spindle axis 42 coaxial guide sleeve axis 198 by the hydraulic control unit 260 and thus also by the machine controller 270th

is controllable, so that the precision of the leadership of the material bar of the respective machining can be adjusted.

In order to be able to perform a long turning according to the Offenbacher system with such a workpiece guide bushing 160, the workpiece guide bushing 160 in the direction of the respective workpiece spindle axis 42 relative to the material rod firmly clamped with the clamping element 62 in the workpiece spindle 40 corresponding to FIG the processing progress during long turning displaced.

The displacement of the respective workpiece guide bushing 160 takes place, as shown in FIGS. 13 and 14, by a tool carrier 70 associated with the respective spindle station S 1 to S 6, whose tool holder 282 is provided with a driver fork 284 which has two fingers 286 and 288, so that In a gap 292 between these two fingers 286, 288 a Mitnehmerarm 294 can be accommodated, which is arranged for example on the outer housing 192 of the respective workpiece guide bushing 160.

In this case, the fingers 286 and 288 of the driver fork 284 extend, for example, parallel to the X direction along which the respective tool holder 282 is movable by means of the respective tool carrier 70, wherein the driver fork 284 is dimensioned such that it moves from the material bar during movement of the tool holder 282 WS way out of engagement with the - -

Mitnehmerarm 294 comes, so that a decoupling between the tool holder 282 and the workpiece guide bushing 160 takes place, while upon movement of the tool holder 282 in the direction of the material rod WS the driving arm can be received in the space 292 between the fingers 286 and 288 of the driving fork.

In this position, in which the Mitnehmerarm 294 between the fingers 286 and 288 of the Mitnehmergabel 284, can be moved by moving the tool carrier 70 in the Z direction, the workpiece guide bushing 160 also parallel to the Z-direction and thus coaxial with the workpiece spindle axis 42 relative to move the workpiece spindle 40 fixed material rod WS with the tool holder 282.

In the case of the spindle stations Sl to S5, in each of which two tool carriers 70 are assigned, one of the tool carriers 70 is in each case with the

Mitnehmergabel 284 and is thus of the machine control 270 for the processing of the material rod WS as a significant tool carrier 70 or master tool carrier 70M, viewed while the other tool carrier 70 with respect to its positioning relative to the

relevant tool carrier 70 is moved and thus operates as a slave tool carrier 70S.

This avoids that the tools WZ of the two tool carriers 70, which are assigned to one of the spindle stations S, collide with one another and, on the other hand, prevents a collision with the respective workpiece guide bushing 160, since this is always positioned in such a way that it is due to the driver fork 284 arranged collision-free to the tool WZ of the respective master tool carrier 70M (Fig. 15). - -

In the spindle station Sl, the workpiece guide bushing 160 from a standing near the workpiece spindle head 44 position in a maximum

Distance from the workpiece spindle head 44 standing position in which an insertion of the material rod WS is made to move, the spindle station Sl is assigned as a whole 302 designated displacement device (Fig. 17), which for example comprises a displacement cylinder 304, which is parallel to the respective Workpiece spindle axis 42 is aligned in the spindle station Sl and carries at one end a Verschiebearm 306 which is able to cooperate with the Mitnehmerarm 294 of standing in this spindle station Sl workpiece guide bush 160 to the workpiece guide bushing 160 in a maximum distance from the workpiece spindle head 44 position to be able to bring.

This position can be set individually, for example, by a tool shank 312 of the tool carrier 70M associated with the spindle station S1, wherein the tool shank 312 still carries an end stop 314 for the material bar WS, which in this spindle station S1 with loosened clamping element 62 by the standing in this spindle station Sl Workpiece spindle 40 is pushed through and into the workpiece guide bushing 160th

is pushed until the material rod WS on the workpiece guide bushing 160 on a side facing away from the spindle head 44 for processing (Fig. 18) and abuts the end stop 314.

The material rod WS is thereby guided by the workpiece guide bush 160 at a distance from the spindle head 44, while the tools WZ of the tool carriers 70M and 70S by moving the same in the X direction and optionally in the Z direction on the over the workpiece guide bushing 160 projecting end portion of the material bar at engage the subsequent processing, as shown in Fig. 19. - -

At the same time by engaging the tool WZ of the tool carrier 70M whose Mitnehmergabel 284 moved so far in the direction of the Mitnehmerarms 294 that the Mitnehmerarm 294 between the fingers 286 and 288 and is moved by the movement of the tool carrier 70M in the Z-direction, wherein at the long turning in each case a processing of the material rod, starting from the end E in the direction of the spindle head 44 takes place (Fig. 19).

The machining of the material bar starting from its end E takes place, for example, in the first spindle station S1 over a processing length BL1 by means of the tools WZ of the two tool carriers 70M and 70S (FIG. 19).

After the machining length BL1 has been machined, the tools WZ of the tool carriers 70M and 70S are moved away from the material bar WS in the X direction, so that subsequent indexing of the spindle drum 30 can take place, in which both the workpiece spindle 40 and the associated workpiece guide bushing 160 are common be moved from the spindle station Sl in the spindle station S2.

The tool carriers 70M and 70S associated with the spindle station S2 are moved, for example, during indexing of the spindle 40 in the Z direction to an initial position, in which at least the tool carrier 70M of the spindle station S2 is able to engage the driver arm 294 with its driver fork 284 ,

Upon reaching the spindle station S2, the tools WZ of the tool carriers 70M and 70S respectively provided in this spindle station S2 are then moved in the X direction onto the material bar in order to machine them and in turn simultaneously with the tool carrier 70M - -

associated Mitnehmergabel 284 the Mitnehmerarm 294 to engage around the workpiece guide bushing 160 in accordance with the movements of the tool carrier 70M in the Z direction in the direction of the spindle head 44 to

move.

In addition, in the spindle station Sl, the tool carriers 70M and 70S, for example, during the indexing of the spindle drum 40, again moved to the position shown in Fig. 18, in which the end stop 314 limits the advancement of the material rod WS, so that subsequently again a new material rod WS can be advanced in the spindle station Sl.

In order to avoid unintentional displacement of the workpiece guide bushing 160 relative to the material rod WS during the indexing of the spindle drum 30 and thus the movement of the workpiece guide bushes 160 from the spindle station S1 into the spindle station S2, the machine control 270, which controls the indexing of the spindle drum 30, the hydraulic control unit 260 also controlled such that it increases the hydraulic pressure and thus the radial force in the direction of the material rod WS at all workpiece guide bushings 160 during the indexing of a spindle station S in another spindle station S to the workpiece guide bushing 160 relative to the existing guide jaw set 202 to the material rod WS frictionally against movements parallel to the workpiece spindle axis 42 set.

As soon as the next spindle station, for example the spindle station S2, has been reached, this reinforced radial force of the guide jaw set 202 is released again in the direction of the material bar WS, so that the usual guidance for the long turning of the material bar WS with a provided for the precision of machining radial force in the Workpiece guide bushing 160 during processing in this spindle station, for example, the spindle station S2 can be performed. - -

In the spindle station S2, for example, machining of the material bar WS takes place via the processing length BL2, which adjoins the

Processing length BL1 connects (Fig. 20).

The indexing into the spindle station S3 takes place in the same way as the indexing from the spindle station S1 to the spindle station S2. In the next spindle station S3, again, the tool carrier 70M associated therewith with the driver fork 284 detects the driver arm 294 and is thus able to even while editing in the third

Spindle station S3 to move the workpiece guide bushing 160 parallel to the workpiece spindle axis 42, for example, over the processing length BL3, via which a processing of the material rod WS in the third spindle station takes place (Fig. 21).

In the same way, an indexing of the third spindle station in the fourth spindle station S4, as shown in Fig. 22, wherein a machining of the material rod WS over the processing length BL4 takes place and also entrainment of the workpiece guide bushing 164 by the on the

Mitnehmerarm 294 of the workpiece guide bushing 160 attacking

Driving fork 284.

Also in the fifth spindle station S5 is still a processing of the material rod WS on the processing length BL5 with support of the material rod by the workpiece guide bushing 160, which is at the end of processing over the processing length BL5 near the workpiece spindle head 44, wherein also a displacement of the workpiece guide bushing 160 on the Machining length BL5 by means of the tool carrier 70M arranged Mitnehmergabel 284 takes place (Fig. 23). - -

In the last spindle station S6, as shown for example in FIG. 24, a synchronous spindle 322 is provided which can be pivoted in and can be aligned coaxially with the workpiece spindle 40, so that the machined side of the material bar WS can be grasped with this synchronizing spindle 322 and the parting of the machined part of the material bar WS can be cut off by means of a parting tool 332 from the same near the workpiece guide bushing 160 takes place.

In addition, as shown in FIG. 25, rear side machining of the machined portion of the material bar WS with tools 334 arranged on the tool holder 282 is possible in the spindle station S6, whereby these tools 334 extend, for example, from the tool holder 282 of the tool carrier 70 extend away.

Already during the back side machining, shown in Fig. 25, it is possible to reverse the spindle drum 30 opposite to the previous direction of rotation, so that the workpiece spindle 40 is again in the spindle station Sl, in which first a displacement of the workpiece guide bushing 160 in the maximum of the workpiece spindle head 44, as shown in Fig. 18, and then pushing in the material bar WS and pushing it through the work guide bushing 160, so that processing of a new material bar WS starts (Fig. 19).

In connection with the embodiment described so far was not discussed in more detail how the radial force is generated and controlled. - -

An exemplary embodiment of a hydraulic control unit 260 according to the invention, shown in FIG. 26 and also shown together with the machine controller 270 in FIG. 1, comprises a central pressure supply designated as a whole 342, which is connected to a pressure generating unit 344 which supplies hydraulic medium with a maximum pressure Pmax Provides, which is supplied via a pressure line 346 of the central pressure supply 342.

In the central pressure supply 342, for example, two pressure reducers 352 and 354 are arranged, which further reduce the pressure Pmax provided via the pressure line 346.

For example, the pressure reducer 352 reduces the pressure Pmax to a clamping pressure Ρκ and is connected to a clamping pressure line 356, via which the clamping pressure Ρκ is forwarded, as described in detail below.

The clamping pressure Ρκ is chosen so that when applying the clamping pressure PK in the cylinder chamber 222 of the guide bush 160 and thus when applying this clamping pressure PK on the adjusting piston 218 of the adjusting 218 acting on the guide jaw set 202 that this is passed through the guide jaw set 202 Material rod WS circumferentially clamps and thus the material rod WS relative to the guide sleeve 196 defines so that the total material rod WS relative to the guide ^¬ sleeve 196 is neither rotatable nor in the direction of the respective workpiece spindle axis 42 slidably.

The pressure reducer 354 reduces the pressure Pmax to a value PF, and is connected to a pilot pressure line 358, via which the pilot pressure PF is provided, as described in detail below. - -

The guide pressure PF is chosen so that when this concern

Guide pressure PF in the cylinder chamber 22 and action of this guide ^¬ d ruck PF on the Verstel lkol ben 218 of the guide jaw set 202 on the respective material rod WS circumferentially with a radial force acts, ie he only so large that the guide sleeve 196th together with the guide jaw set 202 in the direction parallel to the respective workpiece spindle axis 42 is still displaceable, but d the material rod WS is guided radially to the guide sleeve axis 198 and thus also radially to the respective workpiece spindle axis 42 precise.

However, the guide pressure PF is so large that the guide jaw set 202 with such a large radial ialkraft circumferentially applied to the material rod WS so strong that due to the friction between the material rod WS and the guide jaw set 202, a rotational drive of the guide sleeve 196 takes place and thus the guide sleeve 196th rotates in the workpiece guide bush 160 with the material rod WS.

For the function of the pressure reducers 352 and 354, these are still connected to a return line 362 for the hydraulic element, which leads to a hydraulic reservoir 364 and is kept essentially unpressurized at the pressure P ₀ .

Starting from this hydraulic reservoir 364, the hydraulic medium is then transferred to the maximum pressure Pmax by means of the pressure generating unit 344.

The Klemmd jerk line 356, ie the Führungsd jerk line 358 and the return line 362 are now guided to a series of pressure switching units 372, each workpiece guide bushing 160 such a pressure switching unit 372 is firmly zugeord net and the pressure in which leading to the respective guide bush 160 Hyd raulikkanal 226 switches to the pressure ^¬ beaufschlag the adjusting piston 218 set. - -

Each of the pressure switching units 372 includes a first switching valve 374 which is connected to the clamping pressure line 356 at a first input 382 and connected to the Führungsd jerk line 358 at a second input 384 and thus is able to output 386 dessel ben either to clamping pressure Ρκ or put on guide pressure PF.

A second switching valve 394 of the respective pressure switching unit 372 has a first input 402 which is connected to the output 386 of the switching valve 374, and a second input 404 which is connected to the return line 362, and an output 406 which communicates with the hydraulic channel 226 is connected.

The second switching valve 394 is thus able to apply at its output 406 either the anl at its input 402 ing pressure corresponding to the Stel development of the switching valve 374 the Klemmd jerk Ρκ or the Führungsd jerk PF corresponds, or at its output 406 the in the return line 362 vorl constricting pressure P ₀ apply, which corresponds to a substantially unpressurized state.

This makes it possible ialkraftniveau reached d urch d ie jeweil strength pressure switching unit 372 during pressurizing of the cylinder chamber 222 and the Verstel lkol bens 218 with the Klemmd jerk Ρκ, the pilot pressure PF or the pressure P ₀ at the guide shoe set 202 are each a differnet iches wheel, which, however, The specific selection of the clamping jerk Ρκ, the guide jaw PF or the pressure Po leads to the different defined radial force levels, which allow optimal process control during long turning. - -

To control the hydraulic control unit 260, at least one actuation of the switching valves 374 and 394 takes place by means of the machine control 270 for engaging the clamping force Ρκ or the guide force PF or the pressure Po which corresponds to a non-thrusting state, the leading radial force level Radial force level or the releasing Radial ial force level of the guide jaw set 202 pretend.

However, there is also the ability to control the pressure reducers 352 and 354 on the part of the machine controller 270 in order, for example, to change the material bar WS d by changing the clamping jerk Ρκ and / or the guide pressure PF, the clamping radial force level and the feel To adapt the new material bar WS to the new material bar WS.

The machining of a material rod WS with such a hydraulic control 260 controlled multi-spindle field is shown for example schematically in FIG. 27 dargestel lt.

As already described, the supply of the material bar WS takes place in the spindle station 1 with the workpiece spindle 40 initially not rotating and the insertion of the material bar WS into the workpiece guide bush 160 up to the end stop 314.

For this purpose, d urch the hydraulic control unit 260, particularly d urch the workpiece guide bush zugeord designated pressure ^¬ switching unit 372, the pressure in the Hydraul ikkanal switched 160 in the spindle station S l 226 to the pressure P ₀ is generated so that the guide shoe set ialkraft 202 no wheel and the guide jaws 204 positioned at a sufficiently large distance from the guide sleeve axis 198, which allows a push-through push the material rod WS. - -

Now in the spindle station S l the material rod WS on a

To bring machining speed and at the same time to achieve that the guide sleeve 196 is at the same speed as the material rod WS, the pressure switching unit 372 causes the clamping pressure PK to be applied to the hydraulic channel 226 so that the guide jaw set 202 d he guide sleeve 196 clamped to the material rod WS sets.

In this state, the workpiece spindle 40 standing in the spindle station Sl can be accelerated from the stationary state (FIG. 27) to the rotational speed n1 by the rotational speed n0, and it is ensured that the guide sleeve 196 engages the material rod WS is slightly accelerated with ^¬ and thus ebenfal ls d the speed nl reached, ie the

Machining the material rod WS is provided in the spindle station Sl means of the tools WZ.

U m now in the processing of the material rod WS by means of tools WZ d the workpiece guide bushing 160 to move parallel to the respective workpiece spindle axis 42, the pressure switching unit 372 switches after reaching the speed nl of the workpiece spindle 40 Füh tion pressure PF on the hydraulic ikkanal 226th , which is chosen so that on the one hand a precise guidance of the material rod WS in the guide jaw ^¬ set 202 radially to the workpiece spindle axis 42 and radially to the guide ^¬ sleeve axis 198 takes place, however, the guide jaw set 202 in the direction parallel to the standing in the spindle station 1 workpiece spindle axis 42 slidably is g leichzeitig, however, the Rad ialkraft with which the clamping jaw set 202 on the material rod WS circumferentially acts so large that due to the friction a rotation entrainment of the guide jaw set 202 and thus the guide sleeve 196 and thus d the guide sleeve 196 during processing d he material bar WS at the speed nl of the workpiece spindle 40 also rotates with the speed nl. - -

When advancing the spindle drum 30 to move the workpiece spindle 40 with the guide bushing 160 from the spindle station S1 to the spindle station S2, as already explained, the workpiece guide bushing 160 is fixed, in particular the guide sleeve 196 is fixed by means of the guide shoe set 202 on the material rod WS to

Prevention of Relativbeweg ung in the direction parallel to the workpiece spindle axis 42 and g leichzeitig a d rehfestes setting the guide sleeve 196 through the clamping jaw set 202 on the material rod d urch

Connecting the Klemmd rucks Ρκ on the hyd raul ikkanal 226 by the pressure ^¬ switching unit 372.

Will be during the drum indexing the speed of the workpiece spindle 40, for example on the speed nl to the speed n2 changed, so has d ies necessarily mean that the Füh approximately sleeve 196 with the Füh approximately ^¬ back set 202 also aufg this speed change ru nd of clamping Radial strength levels.

After reaching the spindle station S2 t he pressure switching unit 372 switches in turn the feet currency pressure PF on the Hyd Raul ikkanal 226 and thus acts of the guide shoe set 202 with the leading wheel ialkraftniveau on t he material rod WS, so that on the one hand a displacement of the workpiece ^¬ guide sleeve 160 and thus the guide sleeve 196 with the clamping jaw ^¬ set 202 in the direction paral lel to the workpiece spindle axis 42 is possible, please include, but at the same time still takes a rotational drive of the guide sleeve 196 at the speed n2.

The next indexing of the spindle drum 30 to r Beweg ung the workpiece spindle 40 from the spindle station S2 in the spindle station S3 is again by connecting the Klemmd rucks Ρκ on the hyd raul ikkanal 226 and thus generating the clamping Rad ialkraftn levels between the jaw set 202 and the Material rod WS, so that a speed ^¬ change, in the workpiece spindle 40, for example, from the speed N2 - -

to the rotational speed N3 causes a corresponding change in speed of the guide sleeve 196 and the clamping jaw set 202, so that after reaching the spindle station S3 turn on a Aufschaltung the Führungsd rucks PF on the hydraulic ikkanal 226 d urch d the pressure switching unit 372 and due to the leading radial force levels the guide sleeve 196 with the clamping jaw ^¬ set 202 also at the rotational speed n3 d is taken rotten, although a displacement of the workpiece guide bushing 160 with the guide sleeve 196 and the clamping jaw set 202 in the direction parallel to the workpiece spindle axis 42 can take place.

In a second embodiment of a workpiece guide bush 160 'according to the invention, dargestel lt in FIG. 28, the guide sleeve 196, the contactor ring 214, the guide jaws 202 are formed with the guide jaws 204 in g leicher way as in the first embodiment and also ls d by the rotary bearing set 194 rotatably mounted in the outer housing 192.

In contrast to the first embodiment is in the second

Embodiment of the Verstel lkol ben 218 'not with the guide sleeve 196 andd Rehend angeord net, but rotatably disposed in the outer housing 192, so that the Zyl inderkammer 222' D rehfest angeord net and by the Verstel lkolben 218 ', the outer housing 192' and a lid 412 of the outer casing is limited.

In this case, however, the adjusting piston 218 'is parallel to the guide sleeve axis 198 in the same way as in the first embodiment

displaceable.

The adjusting piston 218 'acts on a pivot bearing 414, d urch which a with the Führungshü lens 196 d rehbarer and paral lel the Führungsh ülsenachse 198 displaceable support ring 416 is coupled, which has the conical support surface 216, with which the displaceable support ring 416 on the - -

Guide jaw set 202, in particular the pressure surfaces 208 of the guide jaws 204, acts to move them in the radial direction to the guide sleeve axis 198, in the same manner as described in connection with the first embodiment of the workpiece guide bushing 160.

The second embodiment has the advantage that can be omitted by the rotationally fixed adjusting piston 218 ', the pressure-tight hydraulic rotary feeders 224 and thus by the stationary

Arrangement of the cylinder chambers 222 a simple stationary connection with the hydraulic channel 226 can be realized.

Thus, instead of the pressure-tight hydraulic rotary feed 224 in the second embodiment, the pivot bearing 414 is provided which transmits the movements of the adjusting piston 218 'on the sliding support ring 416.

Claims

PAT E NTAN SP RU CHE

1. Multi-spindle turning machine comprising

a machine frame (10),

a spindle drum (30) rotatably mounted on the machine frame (10) about a spindle drum axis (32),

each in a spindle position on the spindle drum (30)

arranged and in each case about a workpiece spindle axis (42) relative to the spindle drum (30) rotatably mounted workpiece spindles (40) for processing in these workpiece spindles (40).

arranged workpieces by rotating the spindle drum (30) about the spindle drum axis (32) in different relative to

Machine frame (10) stationarily arranged spindle stations (Sl to S6) are positionable,

that each workpiece spindle (40) is associated with a workpiece guide bushing (160) for guiding a material rod (WS) held in the workpiece spindle (40) for longitudinal turning, which relative to the respective workpiece spindle (40). is arranged movable in the direction parallel to the workpiece spindle axis (42).

2. Multi-spindle lathe according to claim 1, characterized in that each workpiece guide bushing (160) is guided by means of a foot body (162) on a carrier unit (164).

3. Multi-spindle turning machine according to claim 1 or 2, characterized in that for each workpiece guide bushing (160) a linear guide (168) is provided, which guides the workpiece guide bush (160) in the direction parallel to the workpiece spindle axis (42).

4. Multi-spindle turning machine according to claim 3, characterized in that the linear guide (168) on one of the spindle drum axis (32) facing side of the respective workpiece guide bushing (160) is arranged.

5. Multi-spindle turning machine according to claim 4, characterized in that each linear guide (168) at least one longitudinal guide (166) and one on the at least one longitudinal guide (166) slidably guided and the workpiece guide bushing (160) bearing

Carriage body (174) includes.

6. Multi-spindle lathe according to claim 5, characterized in that the carriage body (174) is part of the foot body (162).

7. Multi-spindle turning machine according to one of claims 3 to 6, characterized in that the linear guides (168) of all workpiece guide bushings (160) are arranged on a common carrier unit (164).

8. Multi-spindle turning machine according to one of claims 2 to 7, characterized in that the carrier unit (164) in a starting from a front side (46) of the spindle drum (30)

extending working space (20) is arranged.

9. Multi-spindle turning machine according to claim 8, characterized in that the carrier unit (164) extends in the direction parallel to the spindle drum axis (32).

10. Multi-spindle turning machine according to one of the preceding claims, characterized in that the carrier unit (164) about the spindle drum axis (32) and in synchronism with the spindle drum (30) is rotatable.

11. Multi-spindle turning machine according to claim 10, characterized in that the carrier unit (164) is non-rotatably coupled to the spindle drum (30).

12. Multi-spindle lathe according to one of the preceding claims, characterized in that the carrier unit (164) is mounted on an end face (46) of the spindle drum (30).

13. Multi-spindle turning machine according to claim 12, characterized in that the carrier unit (164) in the working space (20), starting from the end face (46) of the spindle drum (30) engages.

14. Multi-spindle turning machine according to one of claims 2 to 13, characterized in that starting from and in continuation of the carrier unit (164) a conduit (232) further through the working space (20) and on one of the end face (46) of the spindle drum ( 30) opposite side of the working space (20) emerges.

15. Multi-spindle lathe according to one of the preceding claims, characterized in that each of the workpiece guide bushes (160) comprises a material rod coaxial with the workpiece spindle axis (42) leading guide sleeve (196), the free relative to a

Outer housing (194) of the respective workpiece guide bushing (160) is rotatable.

16. Multi-spindle turning machine according to claim 15, characterized in that the workpiece guide bushing (160) acts by means of the guide sleeve (196) with a radial force on the material rod (WS).

17 multi-spindle lathe according to claim 15 or 16, characterized in that on the material rod (WS) can be applied guide jaws (204) of the workpiece guide bushing (160) in the coaxial with the workpiece spindle axis (42) rotatable guide sleeve (196).

are arranged.

18. Multi-spindle turning machine according to one of claims 15 to 17,

characterized in that each workpiece guide bush (160) has guide cheeks (204) movable radially to a guide axis (198) of the guide sleeve (196).

19. Multi-spindle lathe according to claim 18, characterized in that each workpiece guide bush (160) acts by means of the guide jaws (204) with the radial force on the material rod (WS).

20. Multi-spindle turning machine according to claim 18 or 19, characterized in that the guide jaws (204) are radially adjustable by a medium.

21. Multi-spindle turning machine according to one of the preceding claims, characterized in that for each workpiece guide bushing (160) there is a media supply via the foot body (162) of the respective workpiece guide bushing (160).

22. Multi-spindle turning machine according to one of the preceding claims, characterized in that on the respective foot body (162) a line for driving to the respective workpiece guide bush (160) is guided.

23. Multi-spindle turning machine according to claim 22, characterized in that on the carriage body (174) is a hydraulic supply to a, for example, on the guide jaws (204) acting hydraulic adjusting unit (220).

24. Multi-spindle turning machine according to claim 23, characterized in that hydraulic medium via a to the carriage body (174) guided flexible supply line (246) is guided to the provided in the carriage body (174) hydraulic supply.

25. Multi-spindle turning machine according to claim 24, characterized in that the flexible supply line (246) from one of an end face of the spindle drum (30) opposite side of the working space (20) to the carriage body (174) is guided.

26. Multi-spindle turning machine according to one of the preceding claims, characterized in that the respective workpiece guide bushing (160) by a control unit (260) with respect to acting on the material rod WS to guide the same radial force

is adjustable.

27. Multi-spindle lathe according to one of the preceding claims, characterized in that the workpiece guide bushes (160) are process-dependent controllable with respect to their radial force with which they act on the material rod (WS) for guiding the same.

28, multi-spindle lathe according to one of the preceding claims, characterized in that the workpiece guide bushes (160) by controlling the radial force against movement relative to the material rod (WS) in the direction parallel to the respective workpiece spindle axis (42) can be fixed.

29. Multi-spindle turning machine according to one of claims 26 to 28, characterized in that by means of the control unit (260) the respective radial force is set to a releasing radial force level at which the material rod (WS) relative to the guide sleeve (196) is freely movable and in particular rotatable ,

30. Multi-spindle turning machine according to one of claims 26 to 29,

characterized in that by means of the control unit (260) the respective radial force is set to a leading radial force level at which the material rod (WS) is displaced in the direction parallel to the respective workpiece spindle axis (42) relative to the workpiece guide bush (160), but the guide sleeve (196) is driven by the material rod (WS) due to the friction given by the leading radial force level.

31. Multi-spindle turning machine according to one of claims 26 to 30,

characterized in that by means of the control unit (260), the respective radial force is set to a clamping radial force level, wherein the material rod (WS) in the guide sleeve (196) is clamped and thus relative to the guide sleeve (196) neither parallel to the respective workpiece spindle axis (42 ) shifted relative to the guide sleeve (196) can be rotated.

32. Multi-spindle turning machine according to one of the preceding claims, characterized in that by means of a machine control (270) a control of the workpiece guide bushes (160) is provided, which when advancing the spindle drum (30) the workpiece guide bushings (100) relative to the material rod (WS) Increasing the radial force of the guide jaws (204) fixed against movement in the direction parallel to the respective workpiece spindle axis (42) and after completion of an indexing of the spindle drum (30) the radial force reduced so far that for long rotation, a displacement of the workpiece guide bushing (160) relative to the material rod ( WS) with simultaneous precise support and guidance of the same transversely to the workpiece spindle axis (42) is possible.

33. Multi-spindle turning machine according to one of claims 29 to 32,

characterized in that the machine controller (270) changes the rotational speed of the respective workpiece spindle (40) only in the presence of the clamping radial force level.

34. Multi-spindle turning machine according to one of claims 29 to 33,

characterized in that the machine controller (270) leaves the speed of the respective workpiece spindle (40) unchanged in the presence of the leading radial force level.

35. Multi-spindle turning machine according to one of claims 29 to 34,

characterized in that the machine controller (270) operates the respective workpiece spindle (40) in the presence of the releasing radial force level with respect to their rotational movement at standstill.

36. Multi-spindle turning machine according to one of claims 29 to 35, characterized in that the machine control (270) during the indexing of the spindle drum (30), the speed of the workpiece spindles (40) to the in the next spindle station (Sl to S6) required speed adapts.

37. Multi-spindle turning machine according to one of the preceding claims, characterized in that each spindle station (Sl to S6) at least one tool carrier (70) is assigned, by means of which held by this tool (WZ) both in the X direction transverse to the respective workpiece spindle axis (42 ) and in the Z-direction parallel to the respective workpiece spindle axis (42) is movable.

38. Multi-spindle turning machine according to one of the preceding claims, characterized in that the workpiece guide bushing (160) through the respective tool carrier (70) in the direction parallel to the workpiece spindle axis (42) is displaceable.

39. Multi-spindle lathe according to claim 38, characterized in that in the case of a plurality of tool carriers (70) one of the tool carriers (70) is provided to displace the workpiece guide bush (160), while at least one further tool carrier (70) is controlled by a machine control (270). a tool carrier (70) are subsequently driven and moved.

40. Multi-spindle turning machine according to one of claims 37 to 39,

characterized in that the tool carrier (70) is provided with a first driver element (284) for displacing the respective workpiece guide bushing (160).

41. A multi-spindle turning machine according to claim 40, characterized in that the workpiece guide bush (160) has a second with the first driver element (284) cooperating driver element (294).

42. Multi-spindle turning machine according to claim 41, characterized in that the driver elements (289, 294) can be brought into operative connection or out of operative connection by movement of the tool carrier (70) in the X direction transversely to the workpiece spindle axis (42).

43. Multi-spindle turning machine according to one of the preceding claims, characterized in that a spindle station (Sl to S6) is associated with a displacement device (302), with which in this standing workpiece guide bushing (160) is displaceable.

44. A multi-spindle turning machine according to claim 43, characterized in that the displacement device (302) comprises a displacement cylinder (304) and a displacement arm (306), and that with the

Displacement arm (306), the workpiece guide bushing (160) is displaceable.

45. Multi-spindle lathe according to claim 43 or 44, characterized in that with the displacement device (302), a displacement of the workpiece guide bushing (160) from the respective workpiece spindle head (44) takes place.

46. Method for operating a multi-spindle turning machine, comprising a machine frame (10), a spindle drum (30) rotatably mounted on the machine frame (10) about a spindle drum axis (32), each in a spindle position on the spindle drum (30)

arranged workpieces (WS) by rotating the spindle drum (30) about the spindle drum axis (32) in different relative to the machine frame (10) stationary arranged spindle stations (Sl to S6) are positioned, characterized in that each workpiece spindle (40) has a workpiece guide bushing ( 160) displaced as a workpiece in the direction of the workpiece spindle axis (42) when machining a material rod (WS), and in each of the workpiece guide bushes (160), the material rod (WS) coaxial with the workpiece spindle axis (42) through a guide sleeve (196), which is relative to a

Outer housing (194) of the respective workpiece guide bushing (160) can rotate freely.

47. The method according to claim 46, characterized in that the workpiece guide bushings (160) act on the material rod (WS) by means of the guide sleeve (196) with a varying radial force.

48. The method of claim 46 or 47, characterized in that in the coaxial with the workpiece spindle axis (42) rotatable guide sleeve (196), the material rod (WS) is guided by this can be applied to guide jaws (204).

49. The method according to claim 48, characterized in that the

Guide jaws (204) at each workpiece guide bushing (160) are adjusted radially to a guide axis (198) of the guide sleeve (196).

50. The method according to claim 49, characterized in that the workpiece guide bushings (160) act by means of the guide jaws (204) with the radial force on the material rod (WS).

51. The method according to any one of claims 46 to 50, characterized in that a medium for radial adjustment of the guide jaws (204) is supplied to each workpiece guide bushing (160).

52. The method according to any one of claims 46 to 51, characterized in that via a control unit (260) in the respective workpiece guide bush (160) on the material rod (WS) for guiding the same acting radial force is adjusted.

53. The method according to any one of claims 46 to 52, characterized in that the workpiece guide bushes (160), the radial force with which they act on the material rod (WS) for guiding the same, is controlled process dependent.

54. The method according to any one of claims 46 to 53, characterized in that the workpiece guide bushings (160) can be set by controlling the radial force against movement relative to the material rod (WS) in the direction parallel to the respective workpiece spindle axis (42). Method according to one of claims 46 to 54, characterized in that by means of the control unit (260) the respective radial force is set to a releasing radial force level at which the material rod (WS) is freely movable relative to the guide sleeve (196) and in particular freely rotatable.

Method according to one of Claims 46 to 55, characterized in that the respective radial force is adjusted to a leading radial force level by means of the control unit (260), in which the material rod (WS) moves in the direction parallel to the respective workpiece spindle axis (42) relative to the workpiece guide bushing (160) ) can be moved, however, the guide sleeve (196) is rotated by the material rod (WS) due to the predetermined by the leading radial force level friction.

Method according to one of claims 46 to 56, characterized in that by means of the control unit (260) the respective radial force is set to a clamping radial force level at which the material rod (WS) relative to the guide sleeve (196) neither parallel to the respective workpiece spindle axis (42). displaced still relative to the guide sleeve (196) can be rotated.

WO 2019/052694 _ 5g _ PCT / EP2018 / 059681

58. The method according to any one of the preceding claims, characterized

characterized in that by means of a machine control (270) a control of the workpiece guide bushes (160) is provided, which when moving the spindle drum (30) the workpiece guide bushings (100) relative to the material rod (WS) by increasing the radial force of the guide jaws against movement in the direction is fixed parallel to the respective workpiece spindle axis (42) and after completion of the indexing of the spindle drum (30) the radial force is reduced so far that for long turning a

Displacement of the workpiece guide bushing (160) relative to the material rod (WS) with simultaneous precise support and guide the same transversely to the workpiece spindle axis (42) is possible.

59. The method according to any one of claims 55 to 58, characterized in that the speed of the respective workpiece spindle (40) is changed by the machine control (270) only in the presence of the clamping radial force level.

60. The method according to any one of claims 55 to 59, characterized in that of the machine control (270) the speed of the respective workpiece spindle (40) is left unchanged in the presence of the leading radial force level.

61. The method according to any one of claims 46 to 60, characterized in that of the machine control (270) the respective workpiece spindle (40) is operated in the presence of the releasing radial force level with respect to their rotational movement at a standstill.

62. The method according to any one of claims 55 to 61, characterized in that of the machine control (270) during the

Further switching the spindle drum (30), the speed of the workpiece spindle (40) is adapted to the speed required in the next spindle station (Sl to S6).

63. A method for operating a multi-spindle machine according to the preamble of claim 46 or any of the preceding

Claims, characterized in that each workpiece spindle (40) is associated with a workpiece guide bushing (160) for guiding a material rod (WS) held in the workpiece spindle (40) for longitudinal turning, which is parallel to the workpiece spindle axis relative to the respective workpiece spindle (40) ( 42) is displaced during long turning.

64. The method according to claim 63, characterized in that each spindle station (S 1 to S 6) is assigned at least one tool carrier (70), by means of which a tool (WZ) held by the latter both in the X direction transverse to the respective workpiece spindle axis (42). as well as in the Z-direction parallel to the respective workpiece spindle axis (42) is moved.

65. The method according to claim 63 or 64, characterized in that the workpiece guide bush (160) is displaced by the respective tool carrier (70) in the direction parallel to the respective workpiece spindle axis (42).

A method according to claim 65, characterized in that in the case of a plurality of tool carriers, the workpiece guide bush (160) is displaced with one of the tool carriers (70), while at least one further tool carrier (70) subsequently moves by means of a machine control (270) to the one tool carrier (70) becomes.

67. The method according to claim 65 or 66, characterized in that the respective workpiece guide bush (160) is displaced by a first driver element (284) arranged on the tool carrier (70).

68. The method according to claim 67, characterized in that the workpiece guide bushing (160) through a second, with the first

Driver element cooperating driver element (294) is moved.

69. The method of claim 67 or 68, characterized in that the driver element (289, 294) by movement of the tool carrier (70) in the X direction transverse to the workpiece spindle axis (42) is brought into operative connection or out of operative connection.