Patent Application
20200206822
The invention relates to a multi-spindle lathe, comprising a machine frame, a spindle drum mounted on the machine frame so as to be rotatable about a spindle drum axis, workpiece spindle units each arranged in a spindle position on the spindle drum and each mounted to be rotatable relative to the spindle drum about a workpiece spindle axis, said workpiece spindle units being positionable by rotating the spindle drum about the spindle drum axis into different spindle positions which are arranged statically relative to the machine frame, for machining workpieces arranged in said workpiece spindles.
A multi-spindle lathe of this type is a classic multi-spindle lathe.
In such multi-spindle lathes, however, the problem exists of being able also to machine elongate workpieces in the easiest possible manner without any great constructional complexity being required.
This problem is solved in a multi-spindle lathe of the type mentioned in the introduction according to the invention in that associated with each workpiece spindle is a workpiece guide bushing for guidance of a material bar held in the workpiece spindle for long turning, said material bar being arranged movably relative to the respective workpiece spindle in a direction parallel to the workpiece spindle axis thereof.
The advantage of the solution according to the invention is to be found therein that a conventional multi-spindle lathe can, in a simple way, be configured so that therewith, by means of the workpiece guide bushing, a long turning with material bars is possible.
In particular, it is possible by means of the displaceability of the workpiece guide bushing that the workpiece spindles can be arranged non-displaceably relative to the spindle drum in the direction of the workpiece spindle axis, so that there is no necessity for having to move the workpiece spindles relative to the spindle drum itself for long turning, and thus, in particular, a long turning can be carried out using the Offenbach system.
With regard to the arrangement of the workpiece guide bushing, no further details have so far been given.
It is preferably provided that the workpiece guide bushing is guided by means of a foot member on a carrier unit, wherein the carrier unit is arranged, in particular, in the working area.
In order to be able to implement an exact guidance of the workpiece guide bushing during its movement in the direction parallel to the workpiece spindle axis, for each workpiece guide bushing, a linear guide is preferably provided which movably guides the workpiece guide bushing in a direction parallel to the workpiece spindle axis.
The linear guide could be arranged, for example, in relation to the spindle drum axis lying radially externally on the workpiece guide bushings.
However, it is particularly favourable if the linear guide is arranged on a side of the respective workpiece guide bushing facing toward the spindle drum axis.
With regard to the construction of the linear guide, no details have so far been given in the context of the previously described solution.
An advantageous solution thus provides that each linear guide comprises at least one longitudinal guide and a carriage member which is displaceably guided on the respective at least one longitudinal guide and carries the workpiece guide bushing.
It is thereby particularly favourable if the carriage member is part of the foot member which holds the workpiece guide bushing.
It is conceivable, in principle, to provide a carrier unit for each of the linear guides.
For reasons of constructional and space efficiency, it is particularly favourable, however, if the linear guides of all the workpiece guide bushings are arranged on a common carrier unit.
With regard to the arrangement of the carrier unit, again no further details have so far been given.
It is thus particularly favourable if the carrier unit is arranged in a working area of the machine tool extending from a front side of the spindle drum.
It is thereby preferably provided that the carrier unit extends in a direction parallel to the spindle drum axis.
Preferably, the carrier unit is configured symmetrically to the spindle drum axis according to the number of workpiece spindles.
This means that, for example, with six workpiece spindles of the spindle drum, the carrier unit has a six-fold symmetry to the spindle drum axis and, for example, accordingly carries six linear guides for the six workpiece guide bushings.
In order to sustain the association of the workpiece guide bushings with the material bars 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.
It is thereby ensured that the association of the individual workpiece guide bushings with the individual workpiece spindles is sustained even on rotation of the spindle drum.
This could be achieved by means of a drive provided specifically for the carrier unit.
In the simplest case, it is provided that the carrier unit is coupled to the spindle drum in a rotationally fixed manner.
A solution of particularly suitable construction provides that the carrier unit is mounted on an end face of the spindle drum and thus, in particular, is also carried by the spindle drum.
With this solution, a precise positioning of the workpiece guide bushings relative to the workpiece spindles arranged in the spindle drum is realisable in a simple manner during the whole of the machining process.
Preferably, it is provided in this case that the carrier unit encroaches in the working area starting from the end face of the spindle drum.
A particularly suitable solution provides that, proceeding from, and in extension of, the carrier unit, a duct extends further through the working area and, in particular, emerges from the working area on a side opposite the end face of the spindle drum, so that by means of this duct, lines can easily be guided to the individual workpiece guide bushings.
With regard to the embodiment of the workpiece guide bushings, no detailed information has so far been given in the context of the description above of the solution according to the invention.
An advantageous solution thus provides that each of the workpiece guide bushings comprises a guide sleeve guiding the material bar coaxially with the workpiece spindle axis, said guide sleeve being freely rotatable relative to an external housing of the respective workpiece guide bushing.
This means that by means of such a freely rotatable guide sleeve guiding and, in particular, supporting the material bar, an advantageous supporting of the material bar during its machining is realisable.
It is particularly favourable if the workpiece guide bushing acts by means of the guide sleeve with a radial force on the material bar, wherein the radial force is preferably adjustable with regard to the level of radial force.
It is particularly favourable if guide jaws of the workpiece guide bushing which are placeable on the material bar are arranged in the guide sleeve which is rotatable coaxially with the workpiece spindle axis and thus permit a corresponding support and guidance of the material bar.
In order to be able to pre-set the precision of the guidance accordingly, it is preferably provided that each workpiece guide bushing comprises guide jaws that are movable radially relative to a guidance axis of the guide sleeve axis of the movable guide jaws.
In particular, it is favourable if each workpiece guide bushing acts by means of the guide jaws with the radial force on the material bar.
Thereby, the radial force can be applied and adjusted in a particularly favourable manner.
A particularly simple solution provides that the guide jaws are acted upon by a spring in the direction of their position abutting the material bar and guiding it with a radial force.
In principle, such guide jaws can be mechanically or electrically adjustable.
A particularly simple solution provides that the guide jaws are radially adjustable by means of an adjusting unit or control unit by a medium in order thereby to be able to set, firstly, the precision of the guidance of the material bar and, secondly, the smoothness of the movement relative to the material bar.
The medium can thereby serve to counteract a radial force in the direction of the material bar generated by an elastic element, in order to release the guidance.
Preferably, the medium serves for generating the radial force with which the guide jaws act upon the material bar.
In particular, in order to be able to realise the adjustability of the guidance of the material bar, it is preferably provided that a medium feed to each workpiece guide bushing takes place via the foot member of the respective workpiece guide bushing.
In order to be able to realise such a control of the respective workpiece guide bushing, it is preferably provided that a line for controlling the respective workpiece guide bushings is routed via the respective foot member.
It is hereby favourable, in particular, if a hydraulic feed takes place, for example, via the carriage member to a hydraulic adjusting unit acting on the guide jaws.
It is thereby preferably provided that hydraulic medium is fed, via a flexible supply line routed to the carriage member, to the hydraulic feed provided in the carriage member, wherein the flexible supply line is capable of following the movements of the carriage member parallel to the workpiece spindle axis.
In particular, in this case, it is provided that the flexible supply line is routed from a side of the working area opposite an end face of the spindle drum to the carriage member.
It is particularly favourable if the respective workpiece guide bushing is adjustable by means of a control unit, in particular a medium control unit, in respect of a radial force acting on the material bar for the guidance thereof.
The medium can be, for example, air or a gas.
A preferred solution provides that the medium is a hydraulic medium, which enables an effect on the guide jaws which is realisable with a simple space-saving construction as well as being quick.
In the case of an acuation of the guide jaws with a medium, in particular a medium generating the radial force, an elastic element which acts upon the guide jaws in the direction away from the material bar in order to support a release of the guidance is suitably provided.
It is particularly favourable in the solution according to the invention if the workpiece guide bushings, in respect of their radial force with which they act on the material bar for the guidance thereof, are controllable in a process-dependent manner, so that the precision of the guidance of the material bar can be controlled in a process-dependent manner.
Furthermore, it is preferably provided that the workpiece guide bushings are fixable by controlling the radial force against a movement relative to the material bar in the direction parallel to the respective workpiece spindle axis.
Such a fixing of the workpiece guide bushings can be used particularly advantageously if a spindle drum indexing takes place for moving the workpiece spindles from one spindle station into the next and thereby the danger exists that the workpiece guide bushings move relative to the material bar in a 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 bar is freely movable, and in particular is rotatable, relative to the workpiece guide sleeve.
Alternatively or additionally, by means of the control unit, the respective radial force is set to a guiding radial force level at which the material bar is displaced relative to the workpiece guide bushing, and thus supported and guided on the guide bushing in a direction parallel to the respective workpiece spindle axis, although the guide sleeve is driven by the material bar due to the friction provided by the guiding radial force level.
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 bar is firmly clamped in the guide sleeve and thus can neither be displaced parallel to the respective workpiece spindle axis nor rotated relative to the guide sleeve.
With regard to the possibility that the workpiece guide bushings can be displaced relative to the material bar when shifting the spindle drum, it has proved to be particularly advantageous if by means of a machine control system, a control of the workpiece guide bushings is provided, which on indexing the spindle drum, fixes the workpiece guide bushings relative to the material bar by increasing the radial force of the guide jaws against a movement in the direction parallel to the respective workpiece spindle axis and after ending of an indexing of the spindle drum, reduces the radial force far enough that for long turning, a displacement of the workpiece guide bushing relative to the material bar with simultaneous precise support and guidance thereof transversely to the workpiece spindle axis is possible.
Thus, the possibility exists of selecting the precision of the guidance of the material bar according to the machining and, secondly, when spindle indexing, of fixing the workpiece guide bushing relative to the material bar.
A particularly favourable solution provides that the machine control system changes the rotary speed of the respective workpiece spindle only in the presence of the clamping radial force level, so that it is thereby ensured that the guide sleeve also undergoes the change in the rotary speed of the workpiece spindle.
Furthermore, it is preferably provided that the machine control system leaves the rotary speed of the respective workpiece spindle unchanged in the presence of the guiding radial force level, so that a slight friction is sufficient to ensure the carrying along of the guide sleeve of the workpiece guide bushing at the respective rotary speed.
A further advantageous solution provides that, in the presence of the releasing radial force level, the machine control system operates the respective workpiece spindle at standstill with regard to its rotary motion, which means that at the releasing radial force level, the material bar does not rotate, but can be pushed through the static guide sleeve of the workpiece guide bushing.
Finally, it is suitably provided that, during the indexing of the spindle drum, the machine control system adapts the rotary speed of the workpiece spindle to the rotary speed required in the next spindle station, so that the time of the indexing of the spindle drum can be used to set the respective new rotary speed, wherein suitably during the indexing of the spindle drum, the clamping radial force level is applied and thus necessarily a carrying along of the guide sleeve takes place during the rotary speed change.
With regard to the machining of the material bars, no further details have so far been given.
Preferably, associated with each spindle station is at least one tool carrier, by means of which a tool held thereby is movable both in the X-direction transversely to the respective workpiece spindle axis and also in the Z-direction parallel to the respective workpiece spindle axis.
Preferably, the tool carriers are arranged to be static on the machine frame and associated with the respective spindle stations.
In particular, two tool carriers are associated with at least a part of the spindle stations in order to increase the number of tools available for machining in the respective spindle station.
Furthermore, so far it has not been considered in detail how the displacement of the workpiece guide bushing parallel to the workpiece spindle axis is to take place.
In principle, it is conceivable to associate a displacement drive with each workpiece guide bushing.
Such a displacement drive could be, for example, an electric displacement drive, for example, by means of an adjusting spindle or a toothed bar, or a pneumatic or a hydraulic displacement drive.
However, in order to configure the solution according to the invention particularly simple in constructional terms, it is preferably provided that the workpiece guide bushing is displaceable by means of the respective tool carrier of the, in particular, respective spindle station in the direction parallel to the workpiece spindle axis.
This means that no displacement drive associated specifically with the workpiece guide bushing is required, but rather the displacement of the workpiece guide bushing takes place by means of the at least one tool carrier operating in the respective spindle station.
In the case of a plurality of, for example two, tool carriers associated with a spindle station, it is preferably provided that one of the tool carriers is provided to displace the workpiece guide bushing in the direction of the workpiece spindle axis, whilst further, for example the other, tool carrier or carriers is or are controlled and moved by means of a machine control system provided for control of the tool carriers, following the tool carrier displacing the workpiece guide bushing, so that thereby, a collision of the tools during the machining of the material bar can simultaneously 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 thereby act directly on the workpiece guide bushing in order to displace it.
It has, however, proved to be advantageous if the workpiece guide bushing comprises a second driver element cooperating with the first driver element, so that by means of this cooperation of the driver elements, a displacement of the workpiece guide bushing can be realised.
However, in order to be able, during indexing of the spindle drum and thus also the moving of the workpiece guide bushing with the spindle drum, to release and to re-establish the coupling of the workpiece guide bushings to the statically arranged tool carrier, it is preferably provided that the driver elements are bringable, through movement of the tool carrier in the X-direction transversely to the workpiece spindle axis, into or out of operative connection.
This means, for example, that a movement of the tool carrier in the X-direction initiated, in particular, by a machine control system toward the workpiece spindle axis creates the operative connection between the driver elements and a movement of the tool carrier, initiated in particular by the machine control system, in the X-direction away from the workpiece spindle axis releases the operative connection of the driver elements.
In order to be able to displace the workpiece guide bushing in at least one spindle station easily and, in particular, independently of the tool carriers, it is preferably provided that a displacing device is associated with the one spindle station, with which displacing device the workpiece guide bushing situated therein is displaceable.
Thereby, the possibility exists of displacing the workpiece guide bushing into the desired position in this station without the movability of a tool carrier in the Z-direction having to be used for this.
It is particularly favourable if the displacing device comprises a displacing cylinder and a displacing arm and that the workpiece guide bushing is displaceable with the displacing arm.
Thereby, the displacing arm can act directly on the workpiece guide bushing at each suitable location.
It is particularly favourable if the displacing arm acts on a driver element provided on the workpiece guide bushing, for example, the aforementioned second driver element.
In principle, such a displacing device for displacing the workpiece guide bushing could be implemented in any provided position.
Particularly advantageously, the displacing device can be used if, with the displacing device, a displacement of the workpiece guide bushing away from the respective workpiece spindle head takes place.
In particular, this solution provides that with the displacing device, a displacement of the workpiece guide bushing takes place into the position maximally removed from the workpiece spindle head.
Such a displacement is advantageous, in particular, in the first spindle station in which a feeding of the material bar takes place, since in this station, simultaneously with the feeding of the material bar, the workpiece guide bushing is to be displaced into the position maximally removed from the workpiece spindle head, in which a machining of the material bar in the first spindle station begins.
Then, starting, in particular, from the first spindle station, for example, a displacement of the workpiece guide bushing by a tool carrier associated with the respective spindle station takes place.
Furthermore, the invention relates to a method for operating a multi-spindle lathe comprising a machine frame, a spindle drum mounted on the machine frame so as to be rotatable about a spindle drum axis, workpiece spindles each arranged in a spindle position on the spindle drum and each mounted to be rotatable relative to the spindle drum about a workpiece spindle axis, said workpiece spindles being positionable by rotating the spindle drum about the spindle drum axis, for machining workpieces arranged in said workpiece spindles, into different spindle stations which are arranged statically relative to the machine frame.
In a method of this type, it is provided according to the invention that associated with each workpiece spindle is a workpiece guide bushing which is displaced, during the machining of a material bar as the workpiece, in the direction of the workpiece spindle axis, that in each of the workpiece guide bushings, the material bar is guided coaxially with the workpiece spindle axis through a guide sleeve which can freely rotate relative to an external housing of the workpiece guide bushing.
It is thereby provided in a simple manner to carry out long turning according to the Offenbach system in a multi-spindle machine tool.
It is particularly favourable if the workpiece guide bushings act upon the material bar by means of the guide sleeve with a varying radial force.
For example, it is provided for this purpose that in the guide sleeve which is rotatable coaxially with the workpiece spindle axis, the material bar is guided through guide jaws that are placeable thereon.
It is thereby suitable for exerting the radial force if, in each workpiece guide bushing, the guide jaws can be displaced radially to a guidance axis of the guide sleeve.
The possibility therefore suitably exists that the workpiece guide bushings act by means of the guide jaws with the radial force on the material bar.
In order to generate the radial force, it is suitably provided that a medium is fed to each workpiece guide bushing for radially displacing the guide jaws.
An advantageous possibility provides that, by means of a control unit in the respective workpiece guide bushing, the radial force acting on the material bar for guidance thereof is adjusted, whereby the control unit is preferably a medium control unit with which a pressure of the medium is adjustable.
It is particularly favourable if in the workpiece guide bushings according to the invention, the radial force with which they act upon the material bar for guidance thereof is controlled in a process-dependent manner, so that during the machining process and between the machining processes, the radial force can be varied in each case and can be adapted according to the requirements of the machining process or the activities occurring between the machining processes.
Furthermore, it is preferably provided that the workpiece guide bushings can be fixed by controlling the radial force against a movement relative to the material bar 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 bar is freely movable and, in particular, is freely rotatable relative to the guide sleeve.
Alternatively or additionally, a further solution provides that by means of the control unit, the respective radial force is set to a guiding radial force level at which the material bar can be displaced in a supported and guided manner relative to the workpiece guide bushing in a direction parallel to the respective workpiece spindle axis, although the guide sleeve is co-rotated by the material bar due to the friction provided by the guiding radial force level.
Alternatively or additionally, a further suitable solution provides that by means of the control unit, the respective radial force is set to a clamping radial force level at which the material bar can neither be displaced relative to the guide sleeve parallel to the respective workpiece spindle axis nor rotated relative to the workpiece guide sleeve.
In particular, in an advantageous solution, it is provided that by means of a machine control system, in particular during actuation of the control unit by the machine control system, an actuation of the workpiece guide bushings is provided, which on indexing the spindle drum, fixes the workpiece guide bushings relative to the material bar by increasing the radial force of the guide jaws against a movement in the direction parallel to the respective workpiece spindle axis and after the ending of the indexing of the spindle drum, reduces the radial force far enough that for long turning, a displacement of the workpiece guide bushing relative to the material bar with simultaneous precise support and guidance thereof transversely to the workpiece spindle axis is possible.
A particularly favourable implementation provides that the machine control system changes the rotary speed of the respective workpiece spindle only in the presence of the clamping radial force level, so that it is thereby ensured that the guide sleeve always also performs the change of the rotary speed of the workpiece spindle and so also rotates at the rotary speed of the material bar.
Alternatively or additionally, it is provided that the machine control system leaves the rotary speed of the respective workpiece spindle unchanged in the presence of the guiding radial force level.
A further suitable solution provides that the respective workpiece spindle is operated by the machine control system in the presence of the releasing radial force level at standstill with regard to its rotary motion.
A further favourable solution provides that during the indexing of the spindle drum, the machine control system adapts the rotary speed of the workpiece spindles to the rotary speed required in the next spindle station.
Alternatively or in addition to the aforementioned method features, the invention relates to a method for operating a multi-spindle lathe in which, according to the invention, associated with each workpiece spindle is a workpiece guide bushing for guidance of a material bar which is held in the workpiece spindle for long turning and is displaced relative to the respective workpiece spindle in a direction parallel to the workpiece spindle axis during long turning. An advantageous variant thereby provides that associated with each spindle station is at least one tool carrier, by means of which a tool held thereby is movable both in the X-direction transversely to the respective workpiece spindle axis and also in the Z-direction parallel to the respective workpiece spindle axis.
In particular, the possibility exists thereby that the workpiece guide bushing is displaced by the respective tool carrier in a direction parallel to the respective workpiece spindle axis in order so to position the workpiece guide bushing that only the machined sections of the material bar protrude beyond the workpiece guide bushing.
In particular, in the case of a plurality of tool carriers, it is provided that the workpiece guide bushing is displaced by one of the tool carriers, whilst at least one further tool carrier is moved by means of a machine control system following the one tool carrier, that is, follows its movements.
Thereby, in particular, the one tool carrier operates as closely as possible to the guide bushing and, by means of the at least one tool carrier, at a somewhat greater spacing from the guide bushing.
It is particularly favourable if the respective workpiece guide bushing is displaced by a first driver element arranged on the tool carrier. Furthermore, it is preferably provided in addition thereto 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 to re-establish the coupling between the tool carrier moving the workpiece guide bushing and the workpiece guide bushing, it is preferably provided that the respective driver element is brought, through a movement of the tool carrier in the X-direction transversely to the workpiece spindle axis, into or out of operative connection.
Further features and advantages of the invention are the subject matter of the following description and of the illustration in the drawings of some exemplary embodiments.
An exemplary embodiment shown in
Mounted in the spindle drum housing 14 is a spindle drum identified overall as 30, which is rotatable around a spindle drum axis 32 relative to the spindle drum housing 14.
Thereby, the mounting of the spindle drum 30 takes place via spindle drum bearings 34 and 36 arranged circumferentially to the spindle drum 30, on the front wall 16 and/or the rear wall 18, which mount the spindle drum 30 to be rotatable about the spindle drum axis 32, but non-diplaceably in the direction of the spindle drum axis 32.
As shown in particular in
In particular, the workpiece spindles 40 are held in the spindle drum 30 non-displaceably in a direction parallel to their workpiece spindle axes 42.
As also shown in
Starting from the workpiece spindle head 44, each of the workpiece spindles 40 extends in the direction of its workpiece spindle axis 42 through the spindle drum 30 as far as a clamping drive 50 arranged at 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 carries a rotor 54 of a spindle motor identified as a whole as 60, the stator 56 of which is arranged stationary in the spindle drum 30.
The spindle tube 52 thereby carries a clamping device 62 for a workpiece W in the region of the spindle head 44, said clamping device being actuatable by the clamping drive 50.
In addition, each of the workpiece spindles 40 and each clamping drive 50 associated with one of the workpiece spindles 40 has a central passage 64 through which a material bar WS forming workpieces can be pushed so that a material bar WS is insertable through the clamping drive 50 into the workpiece spindle 40 and is movable therethrough as far as the clamping element 62, so that the material bar WS ultimately protrudes, with a portion forming the workpiece, beyond the spindle head 44 and is fixable by means of the clamping element 62 for machining.
As shown in
For machining the material bars WS received in the workpiece spindles 40 in the spindle stations S1 to S6, at least one tool carrier 70 is associated with each of the spindle stations S1 to S6, said tool carrier carrying the tools required for the turning machining of the workpiece W (
In the exemplary embodiment shown (
Each of the tool carriers 70 (
For this purpose, an X-displacement drive 76 is provided on the tool carrier 70 (
Furthermore, as shown, for example, in
For the displacement of the sleeve 80 along the sleeve axis 82, a Z-displacement drive identified overall as 90 is provided, which has, penetrating the spindle drum housing 14, a displacing spindle 92, the spindle nut 94 of which is coupled to the sleeve 80 and is situated between the front wall 16 and the rear wall 18 of the spindle drum housing 14. The displacing spindle 92 is furthermore drivable by means of a Z-drive motor 96 which is arranged on the rear side 24 of the spindle drum housing 14.
In order to be able to utilise the space available in the spindle drum housing 14 for the arrangement of sleeves 80 and Z-displacement drives 90 for an optimum number or a maximum number of tool carriers 70, a spindle drum drive identified as a whole as 100 is arranged at a spacing from the rear side 24 of the spindle drum housing 14 and also at a spacing from the rear side 48 of the spindle drum 30, said spindle drum drive having a drive housing 102 which is arranged on the machine frame base 12.
Arranged in a central recess 104 in the drive housing 102 is a driver gear wheel 110 which is rotatable about a gear wheel axis 112 which is arranged coaxially with the spindle drum axis 32.
The driver gear wheel 110 is therein mounted on the peripheral side in a driver gear wheel bearing 114 of the drive housing 102 and has a peripheral toothing 116 for the drive thereof also arranged in the central recess 104.
Furthermore, in the drive housing 102, a gearing unit 120 is provided which drives the driver gear wheel 110, firstly, via the peripheral toothing 116 and, secondly, is drivable by means of a drum drive motor 130.
For the rotary drive of the spindle drum 30 by the driver gear wheel 110, the driver gear wheel 110 is coupled to a drive connecting element identified as a whole as 150, which extends from the driver gear wheel 110 to the spindle drum 30 and is connected to the spindle drum 30 (
In the multi-spindle lathe according to the invention, as shown in
For this purpose, the carrier unit identified overall as 164, itself being coaxial with the spindle drum axis 32 has, for each of the foot members 162, a guide duct 172 delimited in each case on both sides by longitudinal guides 166, in which guide duct the respective foot member 162 is guided by means of a carriage member 174 slidingly guided on the longitudinal guides 166, wherein the respective carriage member 174 is movable parallel to the respective workpiece spindle axis 42 along the longitudinal guides 166 (
Thereby, the longitudinal guides 166 each form, with the guide duct 172 and the carriage member 174, a linear guide 168 for the respective workpiece guide bushing 160.
The respective workpiece guide bushing 160 is displaceable therewith relative to the respective workpiece spindle head 44 over a defined displacement range 176 relative to the respective workpiece spindle head 44.
As shown in
Thereby, the carrier unit 164 is held on the spindle drum 30 fixed, firstly, in a direction parallel to the spindle drum axis 32 and, secondly, in relation to a rotary movement relative to the spindle drum axis 32 and is thus rotatable together with the spindle drum 30 about the spindle drum axis 32, so that thereby, the workpiece guide bushings 160 also always remain oriented in their coaxial alignment with the workpiece spindle axis 42 of the respective workpiece spindle 40 and are displaceable only in the direction of the respective workpiece spindle axis 42 relative to the corresponding workpiece spindle head 44.
As shown in
Arranged in the respective guide sleeve 196 is a guide jaw set 202 which comprises guide jaws 204 which are movable radially to the guide sleeve axis 198, said guide jaws being provided radially externally on their end regions arranged at a spacing from one another in the direction of the guide sleeve axis 198 with pressure surfaces 206, 208 extending conically to the guide sleeve axis 198 and each declining toward the end of the guide jaws 204.
The pressure surfaces 206 thereby abut a complimentary conically formed support surface 212 of a support ring 214 firmly inserted into the guide sleeve 196, whereas the opposite pressure surfaces 208 abut a complementary conically shaped support surface 216 of an annular adjusting piston 218 which is displaceable parallel to the guide sleeve axis 198 and lies within said guide sleeve axis.
The adjusting piston 218 is thereby 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, in order, on a displacement in the direction of the support ring 214, to move the guide jaws 204 radially in the direction toward the guide sleeve axis 198 or, on a displacement away from the support ring 214, to permit a movement in the radial direction toward the guide sleeve axis 198 away therefrom, which is also assisted, in particular, by a spring 205 which acts upon the adjusting piston 218 in order to bias it in the direction away from the support ring 214.
For this purpose, formed between the adjusting piston 218 and the guide sleeve 196 is a cylinder chamber 222 which is connected via a pressure-tight hydraulic rotary feed 224 to a hydraulic duct 226 which extends through the external housing 192 and the foot member 162 and continues into a feed rail 228 formed on the foot member 162 and movable therewith, which extends from the foot member 162 in the direction away from the spindle drum 30 into the working area 20.
To the extent that the feed rail 228 protrudes in the respective position of the workpiece guide bushing 160 beyond the carrier unit 164, it extends into a duct 232 enclosed by a duct covering 234 which, as
At an end 242 of the feed rail 228 facing away from the foot member 162 and facing toward the housing wall 236, a hydraulic connection 244 is provided which, as shown in
Both the hydraulic unit 252 and also the duct covering 234 enclosing the duct 232 co-rotate during a rotation of the spindle drum 30 about the spindle drum axis 32, so that the hydraulic lines 246 extending from the feed rails 228 to the hydraulic unit 252 undergo no torsion, but are only displaced in the direction parallel to the spindle drum axis 32 and possibly transversely thereto in the duct 232, specifically depending upon the position of the workpiece guide bushing 160 with the foot member 162 relative to the respective workpiece spindle head 44.
The hydraulic unit 252 is therein connected to hydraulic lines 254 which are guided via a carrying chain 256 (
The hydraulic lines 254 are themselves connected to a hydraulic control unit 260 (
In the multi-spindle lathe according to the invention, as shown in
In order now to be able to carry out a long turning according to the Offenbach system with such a workpiece guide bushing 160, as already described in detail, the workpiece guide bushing 160 is displaceable in the direction of the respective workpiece spindle axis 42 relative to the material bar firmly clamped with the clamping element 62 in the workpiece spindle 40 according to the machining progress during long turning.
The displacement of the respective workpiece guide bushing 160 takes place, as shown in
Thereby, 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, on a movement of the tool holder 282 away from the material bar WS, the driver fork comes out of engagement with the driver arm 294, so that a decoupling takes place between the tool holder 282 and the workpiece guide bushing 160, whilst on a movement of the tool holder 282 in the direction of the material bar WS, the driver arm can be accommodated in the intermediate space 292 between the fingers 286 and 288 of the driver fork.
In this position in which the driver arm 294 lies between the fingers 286 and 288 of the driver fork 284, by means of a movement of the tool carrier 70 in the Z-direction, the workpiece guide bushing 160 can also be moved parallel to the Z-direction and thus also coaxially with the workpiece spindle axis 42 relative to the material bar WS fixed in the workpiece spindle 40, together with the tool holder 282.
In the case of the spindle stations S1 to S5 in each of which two tool carriers 70 are arranged, in each case, one of the tool carriers 70 is provided with the driver fork 284 and is thus regarded by the machine control system 270 for the machining of the material bar WS as the definitive tool carrier 70 or the master tool carrier 70M, whereas the other tool carrier 70 is moved with regard to its positioning relative to the definitive tool carrier 70 and thus functions as a slave tool carrier 70S.
It is thereby prevented that the tools WZ of the two tool carriers 70 that are associated with one of the spindle stations S collide with one another and also that a collision with the respective workpiece guide bushing 160 takes place, since said bushing is always positioned, by reason of the driver fork 284, so that it is arranged in a collision-free manner relative to the tool WZ of the respective master tool carrier 70M (
In order to be able to displace the workpiece guide bushing 160 in the spindle station S1 from a position situated near the workpiece spindle head 44 into a position at a maximum distance from the workpiece spindle head 44 in which an insertion of the material bar WS takes place, a displacing device identified overall as 302 is associated with the spindle station S1 (
This position can be individually specified, for example, by means of a tool shaft 312 of the tool carrier 70M associated with the spindle station S1, wherein the tool shaft 312 also carries an end stop 314 for the material bar WS which, with the clamping element 62 released, is pushed through the workpiece spindle 40 situated in this spindle station S1 and into the workpiece guide bushing 160 until the material bar WS protrudes beyond the workpiece guide bushing 160 on a side facing away from the spindle head 44 for machining (
The material bar WS is thereby guided through the workpiece guide bushing 160 at a spacing from the spindle head 44, whilst the tools WZ of the tool carriers 70M and 70S enter into engagement through movement thereof in the X-direction and, if appropriate, in the Z-direction on the end portion of the material bar protruding beyond the workpiece guide bushing 160 during the subsequent machining, as shown in
At the same time, by means of the bringing into engagement of the tool WZ of the tool carrier 70M, its driver fork 284 is moved in the direction of the driver arm 294 far enough that the driver arm 294 lies between the fingers 286 and 288 and, by means of the movement of the tool carrier 70M is jointly moved in the Z-direction, wherein during long turning, in each case, a machining of the material bar starting from its end E takes place in the direction of the spindle head 44 (
The machining of the material bar starting from its end E takes place, for example, in the first spindle station S1 over a machining length BL1 by means of the tools WZ of the two tool carriers 70M and 70S (
After machining of the machining length BL1, a movement of the tools WZ of the tool carriers 70M and 70S takes place in the X-direction away from the material bar WS so that subsequently an indexing of the spindle drum 30 can take place in which both the workpiece spindle 40 and also the associated workpiece guide bushing 160 are moved together from the spindle station S1 into the spindle station S2.
The tool carriers 70M and 70S associated with the spindle station S2 are moved, for example, during the indexing of the spindle 40 in the Z-direction into a starting position in which at least the tool carrier 70M of the spindle station S2 is able to embrace the driver arm 294 with its driver fork 284.
On reaching the spindle station S2, the tools WZ of the tool carriers 70M and 70S each provided in this spindle station S2 are again moved in the X-direction toward the material bar in order to machine it and simultaneously again to embrace the driver arm 294 with the driver fork 284 associated with the tool carrier 70M, in order to displace the workpiece guide bushing 160 according to the movements of the tool carrier 70M in the Z-direction in the direction of the spindle head 44.
Furthermore, the tool carriers 70M and 70S are again moved in the spindle station S1, for example, during the indexing of the spindle drum 40, into the position shown in
In order to prevent unwanted displacement of the workpiece guide bushings 160 relative to the material bar WS during indexing of the spindle drum 30 and thus on movement of the workpiece guide bushing 160 from the spindle station S1 into the spindle station S2, by means of the machine control system 270 which controls the indexing of the spindle drum 30, the hydraulic control unit 260 is also controlled, specifically such that in all the workpiece guide bushings 160, it increases the hydraulic pressure and thus the radial force in the direction of the material bar WS during the indexing from one spindle station S into another spindle station S, in order by means of the existing guide jaw set 202, to fix the workpiece guide bushing 160 relative to the material bar WS in force-locking manner against movement parallel to the workpiece spindle axis 42.
As soon as the next spindle station, for example, the spindle station S2 is reached, this increased radial force of the guide jaw set 202 in the direction of the material bar WS is released again, so that the usual guidance of the material bar WS for long turning can be carried out with a radial force in the workpiece guide bushing 160 provided for the precision of the machining during the machining in this spindle station, for example, the spindle station S2.
In the spindle station S2, for example, a machining of the material bar WS over the machining length BL2 which adjoins the machining length BL1 thus takes place (
The indexing into the spindle station S3 takes place in the same way as the indexing from the spindle station S1 into the spindle station S2, wherein in the next spindle station S3, the tool carrier 70M associated therewith also again embraces the driver arm 294 with the driver fork 284 and is therefore in the position, also during the machining in the third spindle station S3, to displace the workpiece guide bushing 160 parallel to the workpiece spindle axis 42, for example, over the machining length BL3 over which a machining of the material bar WS takes place in the third spindle station (
In the same way, an indexing from the third spindle station into the fourth spindle station S4 takes place, as shown in
In the fifth spindle station S5, a machining of the material bar WS over the machining length BL5 also takes place with the material bar supported by the workpiece guide bushing 160 which protrudes, at the end of the machining, beyond the machining length BL5 close to the workpiece spindle head 44, wherein a displacement of the workpiece guide bushing 160 over the machining length BL5 also takes place by means of the driver fork 284 arranged on the tool carrier 70M (
In the last spindle station S6 as shown, for example, in
In addition, as shown in
It is possible even during the rear machining, as shown in
In relation to the exemplary embodiment described above, it was not considered how the radial force is generated and controlled.
An exemplary embodiment of a hydraulic control unit 260 according to the invention, shown in
In the central pressure supply 342, for example, two pressure reducers 352 and 354 are arranged which further reduce the pressure Pmax available via the pressure line 346.
For example, the pressure reducer 352 reduces the pressure Pmax to a clamping pressure Pκ and is connected to a clamping pressure line 356, via which the clamping pressure Pκ is passed on, as described in detail below.
The clamping pressure Pκ is selected so that on application of the clamping pressure Pκ in the cylinder chamber 222 of the guide bushing 160 and thus on application of this clamping pressure Pκ to the adjusting piston 218, the adjusting piston 218 acts on the guide jaw set 202 such that it peripherally clamps the material bar WS fed through the guide jaw set 202 and thus fixes the material bar WS relative to the guide sleeve 196, so that overall, relative to the guide sleeve 196, the material bar WS is neither rotatable nor displaceable in the direction of the respective workpiece spindle axis 42.
The pressure reducer 354 reduces the pressure Pmax to a value PF and is connected to a clamping pressure line 358, via which the guidance pressure PF is made available, as described in detail below.
The guidance pressure PF is thereby selected such that on application of this guidance pressure PF in the cylinder chamber 22 and the action of this guidance pressure PF on the adjusting piston 218, the guide jaw set 202 acts peripherally on the respective material bar WS with a radial force that is only so large that the guide sleeve 196 together with the guide jaw set 202 is still displaceable in the direction parallel to the respective workpiece spindle axis 42, but the material bar WS is precisely guided radially to the guide sleeve axis 198 and thus also radially to the respective workpiece spindle axis 42.
However, the guidance pressure PF is large enough so that the guide jaw set 202 abuts the material bar WS peripherally with a radial force strong enough that due to the friction between the material bar WS and the guide jaw set 202, a rotary driving of the guide sleeve 196 takes place and thus the guide sleeve 196 co-rotates with the material bar WS in the workpiece guide bushing 160.
For the function of the pressure reducers 352 and 354, these are also connected to the return line 362 for the hydraulic medium, which leads to a hydraulic reservoir 364 and is kept substantially pressure free at the pressure P0.
Proceeding from this hydraulic reservoir 364, by means of the pressure generating unit 344, the hydraulic medium is then converted to the maximum pressure Pmax.
The clamping pressure line 356, the guidance pressure line 358 and the return line 362 are now fed to a series of pressure switch units 372, wherein such a pressure switch unit 372 is fixedly associated with each workpiece guide bushing 160 and switches the pressure in the hydraulic duct 226 feeding to the respective guide bushing 160 in order to set the pressure application to the adjusting piston 218.
Each of the pressure switch units 372 comprises a first switch valve 374 which is connected at a first input 382 to the clamping pressure line 356 and at a second input 384 to the guidance pressure line 358 and is thus able to place an output 386 thereof either at clamping pressure Pκ or at guidance pressure PF.
A second switch valve 394 of the respective pressure switch unit 372 has a first input 402 which is connected to the output 386 of the switch valve 374, and a second input 404 which is connected to the return line 362, and an output 406, which is connected to the hydraulic duct 226.
The second switch valve 394 is thus able to place at its output 406 either the pressure applied to its input 402, which corresponds, depending upon the position of the switch valve 374 to the clamping pressure Pκ or the guidance pressure PF, or to place at its output 406 the pressure P0 present in the return line 362, which corresponds to a substantially pressure-free state.
Thus, by means of the respective pressure switch unit 372, when applying the clamping pressure Pκ, the guidance pressure PF or the pressure P0 to the cylinder chamber 222 and the adjusting piston 218, a respectively different radial force level is achieved with the guide jaw set 202, which force level leads however through the specific selection of the clamping pressure Pκ, the guidance pressure PF or the pressure P0 to three different defined radial force levels which permit an optimum processing during long turning.
For control of the hydraulic control unit 260, there occurs by means of the machine control system 270, at least one actuation of the switch valves 374 and 394 for switching on the clamping pressure Pκ or the guidance pressure PF or the pressure P0 corresponding to a pressure-free state in order to pre-determine the clamping radial force level, the guiding radial force level or the releasing radial force level of the guide jaw set 202.
However, the possibility also exists on the part of the machine control system 270 to actuate the pressure reducers 352 and 354 in order, for example, when changing the material bar WS, by changing the clamping pressure Pκ and/or the guidance pressure PF, to adapt the clamping radial force level and the guiding radial force level to the new material bar WS.
The machining of a material bar WS with a multi-spindle lathe controlled by such a hydraulic control system 260 is shown schematically, by way of example, in
As previously described, the feeding of the material bar WS takes place in the spindle station 1 with an initially non-rotating workpiece spindle 40 and the introduction of the material bar WS into the workpiece guide bushing 160 as far as the end stop 314.
For this purpose, by means of the hydraulic control unit 260, in particular by means of the pressure switch unit 372 associated with the workpiece guide bushing 160 in the spindle station S1, the pressure in the hydraulic duct 226 is switched to the pressure P0, so that the guide jaw set 202 generates no radial force at all and the guide jaws 204 are positioned at a sufficiently large spacing from the guide sleeve axis 198 that allows a pushing through of the material bar WS.
In order now to bring the material bar WS in the spindle station S1 to a machining speed and simultaneously to achieve that the guide sleeve 196 is also at the same rotary speed as the material bar WS, by means of the pressure switch unit 372, a switching on of the clamping pressure Pκ to the hydraulic duct 226 takes place by means of the pressure switch unit 372, so that the guide jaw set 202 fixes the guide sleeve 196 clampingly on the material bar WS.
In this state, the workpiece spindle 40 situated in the spindle station S1 can be accelerated from the static state (
In order now during the machining of the material bar WS by means of the tools WZ, to be able to displace the workpiece guide bushing 160 in the direction parallel to the respective workpiece spindle axis 42, after the workpiece spindle 40 reaches the rotary speed n1, the pressure switch unit 372 switches the guidance pressure PF to the hydraulic duct 226 which is selected so that, firstly, a precise guidance of the material bar WS in the guide jaw set 202 takes place radially to the workpiece spindle axis 42 and radially to the guide sleeve axis 198, however the guide jaw set 202 is displaceable in the direction parallel to the workpiece spindle axis 42 situated in the spindle station S1, however at the same time, the radial force with which the clamping jaw set 202 acts peripherally on the material bar WS is so great that due to the friction, a co-rotation of the guide jaw set 202 and thus of the guide sleeve 196 takes place and thus the guide sleeve 196 co-rotates during the machining of the material bar WS at the rotary speed n1 of the workpiece spindle 40, also at the rotary speed n1.
On an indexing of the spindle drum 30, in order to move the workpiece spindle 40 with the guide sleeve 160 from the spindle station S1 into the spindle station S2, a fixing of the workpiece guide bushing 160 takes place, as stated above, in particular a fastening of the guide sleeve 196 by means of the guide jaw set 202 on the material bar WS for preventing a relative movement in the direction parallel to the workpiece spindle axis 42 and simultaneously a rotation-free fixing of the guide sleeve 196 by the clamping jaw set 202 on the material bar by switching on the clamping pressure Pκ to the hydraulic duct 226 by means of the pressure switch unit 372.
If now, during the drum indexing, the rotary speed of the workpiece spindle 40 is changed, for example, from the rotary speed n1 to the rotary speed n2, this necessarily has the consequence that the guide sleeve 196 with the guide jaw set 202 also undergoes this rotary speed change due to the clamping radial force level.
After reaching the spindle station S2, the pressure switch unit 372 again switches the guidance pressure PF to the hydraulic duct 226 and thus the guide jaw set 202 acts with the guiding radial force level on the material bar WS so that, firstly, a displacement of the workpiece guide bushing 160 and thus of the guide sleeve 196 with the clamping jaw set 202 in the direction parallel to the workpiece spindle axis 42 is possible, but simultaneously, as before, a co-rotation of the guide sleeve 196 at the rotary speed n2 takes place.
The next indexing of the spindle drum 30 to move the workpiece spindle 40 from the spindle station S2 into the spindle station S3 also takes place by switching on the clamping pressure Pκ to the hydraulic duct 226 again and thus the creation of the clamping radial force level between the clamping jaw set 202 and the material bar WS, so that a rotary speed change in the workpiece spindle 40, for example, from the rotary speed n2 to the rotary speed n3 also brings about a corresponding rotary speed change of the guide sleeve 196 and of the clamping jaw set 202, so that after reaching the spindle station S3, a switching on of the guidance pressure PF to the hydraulic duct 226 by the pressure switch unit 372 takes place again and, due to the guiding radial force level, the guide sleeve 196 is co-rotated with the clamping jaw set 202, including at the rotary speed n3, although a displacement of the workpiece guide bushing 160 with the guide sleeve 196 and the clamping jaw set 203 in the direction parallel to the workpiece spindle axis 42 can also take place.
In a second exemplary embodiment of a workpiece guide bushing 160′ according to the invention, shown in
In contrast to the first exemplary embodiment, in the second exemplary embodiment, the adjusting piston 218′ is not arranged co-rotatingly with the guide sleeve 196, but is arranged non-rotatably fixed in the external housing 192, so that the cylinder chamber 222′ is also arranged non-rotatably fixed and is delimited by the adjusting piston 218′, the external housing 192′ and a cover 412 of the external housing.
In this case, the adjusting piston 218′ is however displaceable in the same manner as in the first exemplary embodiment parallel to the guide sleeve axis 198.
The adjusting piston 218′ thereby acts on a rotary bearing 414, by means of which a support ring 416 which is rotatable with the guide sleeve 196 and is displaceable parallel to the guide sleeve axis 198 is coupled, said support ring having the conically shaped support surface 216 with which the displaceable support ring 416 acts upon the guide jaw set 202, in particular, upon the pressure surfaces 208 of the guide jaws 204, in order to move them in the radial direction relative to the guide sleeve axis 198, specifically in the same manner as described in relation to the first exemplary embodiment of the workpiece guide bushing 160.
The second exemplary embodiment has the advantage that by means of the non-rotatably arranged adjusting piston 218′, the hydraulic rotary feeds 224 configured to be pressure-tight can be omitted and thus, by means of the stationary arrangement of the cylinder chambers 222, a simple stationary connection to the hydraulic duct 226 is realisable.
Thus, in place of the hydraulic rotary feed 224 configured to be pressure-tight, in the second exemplary embodiment, the rotary bearing 414 is provided which transmits the movements of the adjusting piston 218′ to the displaceable support ring 416.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 121 295.7 | Sep 2017 | DE | national |
This application is a continuation of International application number PCT/EP2018/059681 filed on Apr. 16, 2018. This patent application claims the benefit of International application No. PCT/EP2018/059681 of Apr. 16, 2018 and German application No. 10 2017 121 295.7 of Sep. 14, 2017, the teachings and disclosure of which are hereby incorporated in their entirety by reference thereto.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2018/059681 | Apr 2018 | US |
| Child | 16815817 | US |
