Auxiliary spindle for tool holder turret

Abstract

An auxiliary spindle AS for clamping at least one workpiece W on a toolholder turret 200A-200D, in particular a lathe toolholder turret 200A-200D, for machining operations, has at least a spindle unit 310 configured to mount the auxiliary spindle AS onto a turret port of the toolholder turret 200A-200D, receive the workpiece W and perform a machining operation of the received workpiece W on the toolholder turret. In addition, the spindle unit 310 further includes at least a receiving unit 311 configured to clamp the workpiece W onto the auxiliary spindle AS.

Description

[Technical field]

[0001] This application relates to an auxiliary spindle for positioning a workpiece on a toolholder turret, and more particularly, on a lathe toolholder turret. [Background technology]

[0002] A common type of machine tool, such as a lathe or turret lathe, typically comprises a machine frame which may comprise at least two rotatably mounted work spindles with parallel or coaxial spindle axes facing each other, and a number of tool-holding carriers integrally distributed on the machine frame. Machining of each workpiece is thus typically performed by inserting the workpiece into one of the aforementioned work spindles and bringing it into close proximity with a designated machining tool mounted in one of the integral tool-holding carriers.

[0003] For example, EP 2 714 307 B1 relates to a machine tool, in particular a lathe, which comprises a machine frame, a first work spindle arranged on a spindle carrier face of the machine frame and configured to receive a first workpiece, a second work spindle facing the first work spindle configured to receive a second workpiece, and two movable tool carrier slides on which respective tool-carrying tool carriers, i.e. turrets, can be arranged.

[0004] Likewise, DE 3 609 571 A1 describes a lathe having a holding device arranged centrally in the machine frame, into which a workpiece can be inserted, while independently drivable machining units arranged around the holding device are adapted to machine the fixed workpiece.

[0005] In general, this type of machine tool usually requires that machining tools are provided to allow the most efficient machining of the workpiece while at the same time achieving the maximum possible number of tools that can be used simultaneously. This generally leads to considering implementing tool-holding turrets as tool carriers that are uniformly distributed around the respective workpiece spindles and / or independently movable, leading to both a high degree of flexibility regarding the control of the implemented tools as well as a cost-effective and robust design of the machine tool. However, in contrast, in order to maximize the accessibility of the workpiece, the peripheral area of ​​the work spindle is usually assigned entirely to the working trajectory of the respective tool-holding turret (or analogously to the trajectory of the work spindle), so that this type of machine tool, especially those that use such multiple tool-holding turrets, is reduced in compactness in order to avoid constraints resulting from possible collisions of independently working tool-holding turrets. In addition, as a result of the limitation of the machining of the workpiece to a specific area around the respective work spindle, the area in which the actual machining of the workpiece takes place is relatively small, while a large part of the potential working space of the machine tool remains unused. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] EP2714307B1 [Patent Document 2] DE3609571A1 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, in order to solve the above problems and to improve the machining process of a machine tool, a machining system is proposed having an auxiliary spindle configured for additionally positioning a workpiece on the tool holder turret for machining operations, with the features of the independent claims. Preferred embodiments of the invention are recited in the dependent claims. [Means for solving the problem]

[0008] Thus, the auxiliary spindle used in the machining system of the claimed invention may mainly include at least one spindle unit that is configured to receive at least one workpiece for the auxiliary spindle while at the same time being connectable to a respective tool turret port, such as a tooling station, of a toolholder turret mounted on a machine tool, in particular a lathe. Thus, the spindle unit of the present invention may represent a central interface between a particular toolholder turret and a workpiece to be placed on the toolholder turret by providing a respective connection point for both the toolholder turret and the workpiece.

[0009] In particular, the spindle unit can be preferably configured to be adjustably mountable to a specific type of tool turret port, for example by adjustable connection elements, so that the auxiliary spindle can be integrated into any known tool holder turret type, such as crown turret, drum turret, vertical turret or head turret, to allow connection to the tool holder turret. Alternatively, the spindle unit can also be connectable with a tool holder already mounted on the respective tool holder turret, to allow maximum accessibility for a given auxiliary spindle. The method of connecting the auxiliary spindle to the respective tool turret port via the spindle unit can be equally adaptable to the needs of the respective tool holder turret and can include cap screwing, wedge fixing or collet clamping, although of course any other method of rigidly positioning the auxiliary spindle on the tool holder turret can also be applied.

[0010] Furthermore, in order to enable connection to the at least one workpiece, the spindle unit may additionally comprise at least one receiving unit configured for at least clamping the workpiece on the auxiliary spindle for a machining operation, which likewise leads to a well-defined and robust positioning of the respective workpiece on the toolholder turret. Thus, the claimed auxiliary spindle allows for an accurate and universally usable method of positioning at least one respective workpiece on a given toolholder turret, in particular of a lathe, which allows for an improvement in the efficiency and use of the working space of the lathe by enabling machining operations on the toolholder turret in addition to those performed on the work spindle.

[0011] Based on this, in order to further ensure optimal conditions for any type of precision machining of the clamped workpiece on the toolholder turret, such as milling, drilling or even cutting or grinding processes, the auxiliary spindle can additionally be configured to at least rotate the clamped workpiece along an auxiliary spindle axis defined by the internal spindle geometry of the auxiliary spindle, whereby the characteristics of the rotational movement of the respective workpiece (rotational speed, torque, etc.) can be adjusted by the auxiliary spindle itself or by additional elements depending on the respective requirements given for the specific machining process, allowing maximum versatility of the auxiliary spindle when applied to the associated lathe.

[0012] In addition, in a preferred embodiment, the auxiliary spindle can likewise be configured to interact with the drive system of the toolholder turret to which it is attached, allowing for a more accurate machining process of the clamped workpiece. For example, the auxiliary spindle can preferably be connected to the respective toolholder turret, and by mounting the spindle unit of the auxiliary spindle to this at least one toolholder turret, the auxiliary spindle, in particular its degrees of freedom, can be controlled by the aforementioned drive system, allowing the auxiliary spindle to be driven by the same power source as the common tool of the toolholder turret. Here, for example, by mounting the spindle unit to the respective tool turret port, the auxiliary spindle can be configured to mechanically connect to the drive of the given toolholder turret, such as an implemented motor, and thus can respond according to the target movements set by the given drive system and modify its movement pattern, in particular the rotational movement of the clamped workpiece.

[0013] The auxiliary spindle can also be connectable to a drive located outside the toolholder turret, for example by a drive of an independent toolholder mounted on the toolholder turret, and even if no internal drive is included, it can only be steered by the aforementioned drive system of the toolholder turret, so as to allow the mounting and control of the auxiliary spindle by the toolholder turret. Likewise, the auxiliary spindle itself can include a mounted drive and can be configured to receive and realize process commands sent by the toolholder turret system, for example by a wireless signal transmission system occurring between the auxiliary spindle and the toolholder turret, leading to a high adaptability and integration of the auxiliary spindle for a given toolholder turret type. Thus, with a given characteristic of the auxiliary spindle, both a maximum customizability of the auxiliary spindle and an accurate and reliable control of the clamped workpiece can be realized.

[0014] Furthermore, with regard to the fixation of the clamped workpiece on the auxiliary spindle, each spindle unit can include, integrated into or in addition to the receiving unit, at least one clamping structure specially designed to hold the workpiece on the auxiliary spindle. The receiving unit can thus include, for example, an adjustable sleeve that can be controlled by the above-mentioned tool turret system or any other control element to hold the workpiece firmly when inserted. Here, the clamping can be caused by mechanically tightening said sleeve, for example by an axial joint wrench, or by electrically, hydraulically or pneumatically adjusting its radius so that its inner surface contacts the inserted workpiece and ensures zero play for the subsequent machining operation, allowing precise processing steps in the tool holder turret. In addition, to further improve the accuracy of the machining of the workpiece, the sleeve can also be oriented in a way that automatically aligns the clamped workpiece coaxially with the above-mentioned auxiliary spindle axis, thus preventing imbalance during the rotation of the workpiece as well as wear and inaccuracies in the respective machining elements.

[0015] Also, instead of or in addition to the above sleeve, the receiving unit can further preferably include a chuck mechanism including at least one chuck for clamping the workpiece to be machined. More specifically, the chuck to be used for clamping is a self-centering chuck or collet and can include multiple jaws that are independently controllable to hold even irregularly shaped workpieces firmly, thus further improving the accessibility of the auxiliary spindle for different machining processes. In addition, according to the above sleeve, the chuck mechanism described herein can also be configured to align the workpiece coaxially with the auxiliary spindle axis, for example by adjusting its jaws respectively, so that the subsequent machining can be performed under similarly high performance conditions.

[0016] Also apart from the above mentioned clamping mechanisms, other ways of rigidly fixing the workpiece onto the spindle unit may of course be applicable, including using a workpiece gripper mechanism, an electromagnetic freewheel fixing or a simple wedge pinning process. Likewise, any of the above mentioned mechanisms are preferably constructed as stand-alone clamping elements to the spindle unit or as additional, exchangeable supplementary tools for holding the respective workpiece in the auxiliary spindle, so that the respective auxiliary spindle can be best adapted as possible for the corresponding workpiece to be machined.

[0017] In addition, the auxiliary spindle of the present invention can also be configured to organize the clamped workpieces in such a way that the most efficient machining on the tool holder turret can be achieved for the respective lathe in which the clamped workpieces are to be used. For example, the receiving unit of the auxiliary spindle is preferably aligned with the auxiliary spindle axis of the auxiliary spindle and can be constructed as a tubular or any other kind of hollow shape that fits the respective shape of the workpiece to be clamped, so that the possibility of creating a contact point for clamping at any given location on the workpiece arises. As a result, in addition to the limited workpiece orientation possibilities known from conventional workpiece holder elements, such as work spindles, the receiving unit of the present invention can improve the range of ways to align the workpiece for machining.

[0018] In a preferred embodiment, for example, the receiving unit can additionally be configured to clamp the workpiece at at least one contact point, for example in the center of the workpiece, so that at least two opposite ends of the clamped workpiece remain exposed, thus allowing simultaneous independent machining on at least two sides. On the other hand, due to the advantageous structure of the receiving unit described above, the receiving unit can also additionally include at least two different clamping sides arranged at a distance, each side being configured to clamp the workpiece, for example by the aforementioned clamping mechanism, resulting in the possibility of receiving and machining at least two separated workpieces simultaneously in the auxiliary spindle. Thus, apart from the general and limited clamping methods known from normal workpiece holders, the auxiliary spindle of the present invention provides multiple capabilities of how to align and handle the clamped workpiece received for machining, again leading to an increased adaptability of the auxiliary spindle for the specific machining process to be applied.

[0019] In addition, further features of the auxiliary spindle can be described as follows: In addition to the rotation of the auxiliary spindle using the above-mentioned external tool turret drive, the auxiliary spindle can also include at least one rotating element, for example a bearing such as a plane bearing, a ball bearing, a magnetic bearing or a hydrodynamic bearing, which can rotate at least one clamped workpiece along the auxiliary spindle axis independently of the above-mentioned drive system of the corresponding toolholder turret. Here, the rotating element can be built around the clamped workpiece, for example, or at least connected to a receiving unit that connects the workpiece with the auxiliary spindle, so that the clamped workpiece can be rotated coaxially by the rotation of the rotating element, while at the same time decoupling it from the drive system of the respective toolholder turret. Thus, by being able to rotate the workpiece by a given rotating element, for example by an external drive, independently of the drive system of the connected toolholder turret, an additional possibility of driving the rotation of the workpiece can be provided, thus allowing a more precise and / or controlled movement of the workpiece as (potentially) possible by the toolholder turret itself.

[0020] Therefore, in order to alternate between such emergency drive possibilities, the auxiliary spindle may furthermore also include an additional switching unit configured at least to change and define the primary drive used to rotate the clamped workpiece in the auxiliary spindle, preferentially. In general, said switching unit may therefore be configured to change the state of the spindle unit between an "active state" allowing active rotation of the clamped workpiece by the aforementioned drive system of any toolholder turret, and an "idle state" allowing free rotation of the workpiece by the above-mentioned rotating elements (and thus independent of the drive system of the toolholder turret). Here, switching between these states may be realized, for example, by mechanically locking / releasing the rotational movement of the rotating elements or by connecting / disconnecting the auxiliary spindle from the drive connected to the drive system of the respective toolholder turret. Similarly, in a preferred embodiment, the switching unit can also be configured to simultaneously activate and / or inhibit both states, e.g. so that during a cutting process a rigid, immobile positioning of the clamped workpiece can be achieved (both states "off"), while at the same time, if additional rotational force is required, the rotational movement driven by the drive system of the toolholder turret can be supplemented by an external drive via a rotating element (both states "on").

[0021] Thus, with the auxiliary spindle implemented in the machining system of the claimed invention, a highly adaptable machining element is provided that allows both a robust and functional attachment to the toolholder turret of a given lathe as well as a precisely controllable positioning, by clamping, of at least one workpiece for a machining process on said toolholder turret. Furthermore, the aforementioned clamping and orientation mechanisms provided by the auxiliary spindle allow the machining of the workpiece to be specifically customized to the specific requirements needed for its processing, while at the same time, the additional machining possibilities made possible by the auxiliary spindle can dramatically increase the efficiency of any suitable lathe as well as the utilization of the working space, since the implemented receiving unit allows multiple machining steps to be performed simultaneously.

[0022] Therefore, in order to more clearly show the advantages of the aforementioned elements, the technical features of the machine system of the present invention including the above-mentioned auxiliary spindle will be highlighted hereinafter.

[0023] In general, a machining system with the features of the claimed invention for machining at least one workpiece on a toolholder turret of a lathe can preferentially include at least one toolholder turret of any type capable of mounting a number of tools on at least one tool turret port already referred to above, as well as at least one of the aforementioned auxiliary spindles mounted on the at least one toolholder turret or any other toolholder turret implemented in the respective machining system. The machining system described here can consequently mean a conventional turret lathe as generally known for drilling, cutting or any other type of machining strategy, but can equally be implemented on other machine tools capable of integrating a toolholder turret, such as drilling machines, hobbing machines or shapers. Likewise, due to the well-defined control of the workpiece in the auxiliary spindle, the machining system of the claimed invention can be applicable to both fixed as well as live tooling processes, in particular CNC-driven tooling, and can include at least a semi-automatic, if not fully automatic, control system controlling the respective machining elements.

[0024] Therein, one feature of the claimed machining system can be seen in providing, as already mentioned above, reliable and precise machining of the workpiece on at least one toolholder turret implemented in a machine tool and by means of the aforementioned auxiliary spindle, where "machining" in this context may equally refer to any known processing of a clamped workpiece, and thus for example milling, chucking, drilling or any other method of precise processing of the respective workpiece.

[0025] Thus, to define the minimum requirements of the claimed machining system, said machining system may at least be configured to position a workpiece on a corresponding toolholder turret via an auxiliary spindle, and thus the machining system of this embodiment may be configured to at least fix a received (i.e. clamped) workpiece in a predetermined position such that machining (and its associated advantages) on the toolholder turret can be achieved.

[0026] Based on the above-mentioned characteristics of the auxiliary spindles, the machining system can preferentially be configured to additionally rotate the clamped workpiece on the receiving unit of the auxiliary spindle along at least one auxiliary spindle axis, so that dynamic cutting processes such as milling or drilling can be applied without requiring additional rotation drives for the respective machining tools. Here, as mentioned above, the rotation of the workpiece by the machining system can be realized by connecting the auxiliary spindle, in particular the spindle unit, to the drive system of the toolholder turret, so that the rotation of the spindle (and therefore of the clamped working piece) can be precisely adjusted. More specifically, by connecting the auxiliary spindle to an internal drive, such as a motor, of the toolholder turret, the rotation of the workpiece can be triggered, for example, by a torque generated by the aforementioned drive and transmitted to the respective auxiliary spindle to instantly alternate the rotation characteristics of the workpiece when necessary (for example when changing the machining process or using another tool).

[0027] Furthermore, in order to machine the clamped workpiece within the present invention, the clamped workpiece in the claimed machining system may at least be able to interact with a machine tool also present in the machining system. The machining system may then be further configured to machine the clamped workpiece in the receiving unit of the auxiliary spindle with at least one machining tool mounted on one of the toolholder turrets of the machining system and / or at least one machining tool mounted on the main spindle, so as to realize a processing of the respective workpiece, in particular with the aid of live tooling. In doing so, the machining may be carried out successively using the tools provided by at least one toolholder turret or the main spindle of the machining system, or may be carried out simultaneously with several machining tools mounted on the same or different mounts, thus allowing the most efficient processing of the workpiece on the toolholder turret. In addition, as mentioned above, the auxiliary spindle is configured to expose several machining areas of the workpiece (or even several workpieces) for machining, so that the processing time in a machine tool such as a lathe can be significantly improved.

[0028] Thus, with a given machining system capable of additionally positioning and processing respective workpieces on the toolholder turret, separately or in combination with machining conventionally performed on the main spindle of the respective machine tool, a greatly enhanced machining process can be realized which may lead to faster, more accurate and, above all, more adaptive processing of one or more workpieces. Moreover, as will be explained hereinafter, due to the large degrees of freedom typically included in a given toolholder turret of a machine tool, in particular a lathe, the claimed machining system can also enable a much more extensive interaction between the machining elements, ultimately leading to much more complex and coordinated machining steps than a comparable machine tool can perform.

[0029] Therefore, the machining system of the claimed invention can also be configured as a basis to adjust the position of the clamped workpiece to the receiving unit of the respective auxiliary spindle and / or the orientation of its corresponding auxiliary spindle axis, for example by moving the tool holder turret, on which the auxiliary spindle is mounted, at least along the respective turret axis and / or by performing a translational movement along any three-dimensional axis, for example by using guide rails also implemented in the machining system. Thus, by simply utilizing the guide systems already present in conventional machine tools (e.g. for controlling the tool position), a precise allocation of the clamped workpiece to any given machine tool can be realized, thus avoiding the implementation of additional drives and reducing the potential costs of the system. Furthermore, based on the thus created degrees of freedom of the clamped workpiece, various machining steps can be developed that can further enable more advanced and complex interactions between the implemented machining elements so as to further improve the tool processing in the machine tool.

[0030] On the other hand, for example, based on the above possibilities of dynamically controlling the position of the clamped workpiece, a transfer process can be performed between at least the tool-holding turret, which mounts the auxiliary spindle on which the workpiece is clamped, and the main spindle of the machining system, or generally any work spindle. The machining system can thus be configured to transfer the clamped workpiece from at least one main spindle of the machining system to the tool-holder turret via at least one auxiliary spindle mounted on said tool-holder turret and / or back from the tool-holder turret to at least one main spindle, respectively, allowing successive machining processes at different positions of the machine tool by successively passing the workpiece through predefined machining areas. Here, said transfer process can be realized, for example, by first approaching the workpiece (for example fixed by a fixing element of the main spindle) by the auxiliary spindle and clamping it via a clamping mechanism implemented in its receiving unit. The main spindle can then be configured in a next step to loosen its grip and finally achieve a transfer between both spindles, for example by receiving a corresponding command from the auxiliary spindle via a connection between these two elements built into a transmitter / receiver, or by an automated machining protocol such as is typically implemented in a CNC lathe. Moreover, the same mechanism can be reversed to hand over the workpiece clamped by the respective auxiliary spindle.

[0031] On the other hand, the transfer of the workpiece does not have to be limited between the auxiliary spindle and the main spindle itself. On the contrary, the machining system of the claimed invention can likewise include at least two or more tool holding turrets, each of which is fitted with at least one auxiliary spindle, between which the workpiece can be transferred. Correspondingly, the machining system can also include, in a preferred embodiment, at least a first and a second tool holder turret, each of which is fitted with at least a first and a second auxiliary spindle, and the machining system can be configured to transfer the workpiece from one of the tool holder turrets (e.g. from the receiving unit of the first auxiliary spindle) to the other (e.g. to the receiving unit of the second auxiliary spindle) by the movement of the at least two tool holder turrets, similar to the aforementioned interaction between the main spindle and the auxiliary spindles. As a result, a given machining system allows for the regular transfer of each workpiece to any given working area reachable by the main or auxiliary spindle, thus allowing both a redistribution of the workpieces throughout the machine tool to allow multiple, locally distinct machining areas independent of the limited accessibility of the main spindle, as well as a dynamic and adaptable machining circulation of the workpieces facilitating the generation of rapid production lines within the respective machine tool. Thus, a faster, more efficient and, above all, space-saving machining process can be achieved compared to conventional machine tools.

[0032] Also, despite the advantages resulting from the aforementioned redistribution of workpieces for machining operations in the machining system of the present invention, it must be emphasized again that the corresponding invention does not just involve mounting an additional workpiece holder on a machine tool such as a lathe, but is rather based on the effect of utilizing an existing tool holder turret to position and assign each workpiece for machining by an auxiliary spindle. Thus, in contrast to a common machine tool that includes several fixed elements (e.g. several work spindles mounted on a lathe) that rigidly position the workpieces for machining operations, the workpiece holder of the claimed invention does not occupy additional space or require a separate drive system, but operates on already existing elements (i.e. at least one tool holder turret) that are usually used to control the tools for machining the workpieces. As a result, as a fundamental difference between the machining system of the claimed invention and a common machine tool, the tool holder turret of the machining system of the claimed invention can obtain a hybrid state and can therefore be configured to mount both at least one auxiliary spindle for positioning and controlling the workpieces, as well as at least one additional machining tool capable of machining the respective workpiece.

[0033] It is therefore equally clear that because of this hybrid state, at least the toolholder turrets fitted with at least one auxiliary spindle can be configured to both position and control a workpiece clamped on the receiving unit of the auxiliary spindle for a machining operation on the toolholder turret, and also position at least one attached machining tool for machining the respective workpiece (or any other workpiece available to the machining system), generating a dual function for any toolholder turret fitted with at least one auxiliary spindle.

[0034] Now, this dual functionality can lead to several advantages that can be exploited by the machining system of the present invention. Due to the ability to mount both a workpiece clamped by the auxiliary spindle as well as a compatible machining tool, for example, a toolholder turret in the machining system of the claimed invention can be configured to simultaneously control at least one machining tool for processing a workpiece (e.g., at the work spindle) while at the same time steering and placing another workpiece clamped on the receiving unit of the auxiliary spindle for a secondary machining operation, thus again allowing multiple processing steps at the same time. Now, the at least one machining tool mounted on each toolholder turret of the present invention can be configured only to process a workpiece placed outside its respective toolholder turret, or it may be equally possible to machine a workpiece mounted on the same toolholder turret, by means of customizable adjustment elements such as, for example, internal guide rails, so that even a machining process that is completely independent of any external machining elements (e.g., a work spindle or another toolholder turret) is possible. The tool holder turret implemented in the machining system of the present invention can also preferably include a plurality of mounted machining tools that can be independently, or at least sequentially, controlled for machining operations resulting in faster processing of respective workpieces.

[0035] Also, in a particularly preferred embodiment, at least one toolholder turret of the claimed machining system can also be configured to mount, in addition to at least one machining tool, at least two or more auxiliary spindles capable of individually clamping at least one workpiece for the machining process. Consequently, similar to the above case where the toolholder turret can include multiple machining tools, the machining system of the claimed invention can also be configured to independently position and control multiple workpieces clamped on the auxiliary spindles present in the system by at least one respective toolholder turret. Thus, machining of these workpieces can likewise be performed individually and / or sequentially, such that the machining system can be configured to independently machine each of the workpieces clamped in the auxiliary spindles by at least one machining tool clamped on the existing main spindle and / or at least one machining tool mounted on one of the toolholder turrets of the machining system. Moreover, the machining of each of the clamped workpieces can again be performed simultaneously and / or temporally distinct, allowing maximum adaptability of the respective machining system for any given machining operation.

[0036] A further advantage of the machining system of the claimed invention may also result from the possibility of decoupling the rotational movement of the clamped workpiece by means of a rotating element implemented in the receiving unit of the above-mentioned auxiliary spindle. More specifically, since the aforementioned rotating element of the auxiliary spindle may allow a rotational movement of the workpiece independent of the internal drive of the respective toolholder turret, the machining system of the claimed invention may additionally include at least one rotating tool mounted on one of the toolholder turrets of the system configured to externally and / or supplementarily drive the rotation of the clamped workpiece along the auxiliary spindle axis. Here, to achieve this, the rotating tool may include fastening elements such as dynamic clamps, chucks or any other object capable of firmly holding the respective workpiece, and the machining system may be configured to physically connect said rotating tool to the respective clamped workpiece with the aid of such fastening elements. Furthermore, a supplemental rotation of the clamped workpiece may then be generated by the rotating tool, for example by generating an additional torque that is transmitted to the clamped workpiece via the fastening elements, such that the rotation of the corresponding workpiece may be controlled by the rotation alone or in conjunction with the drive generated by the internal drive system of the respective toolholder turret. Thus, improved control of the workpiece may be achieved by a rotating tool mounted on at least one of the toolholder turrets implemented in the machining system, both by supplementing the additional rotational force, if required, as well as by further stabilizing the workpiece during rotation due to the additional contact area generated by the fastening elements.

[0037] As a result, it is shown that the machining system of the claimed invention can include many advantages compared to machining operations typically used on machine tools such as lathes. More precisely, the possibility of additionally mounting at least one workpiece on the toolholder turret of the machining system by means of an auxiliary spindle and additionally processing the workpiece on said toolholder turret allows the implementation of more efficient, coordinated and faster machining strategies that are not possible with any conventional machine tool. In addition, due to said machining system, multiple machining methods can be generated that cannot be offered or performed by conventional machine tools.

[0038] Here, these machining methods may include at least a step of clamping at least one workpiece by a receiving unit of an auxiliary spindle on a toolholder turret of the above-mentioned machining system, as well as a step of rotating the clamped workpiece along the auxiliary spindle axis for machining the clamped workpiece.

[0039] Furthermore, the machining method also includes machining a workpiece clamped on each toolholder turret with at least one tool mounted on the at least one toolholder turret and / or a tool mounted on a primary spindle implemented in the machining system; pivoting the clamped workpiece by rotating a toolholder turret on which each auxiliary spindle is mounted along a turret axis and / or moving the clamped workpiece by translating said toolholder turret in at least one of three directions so as to accurately allocate the workpiece for the machining operation; connecting the auxiliary spindle to a drive system of the toolholder turret by at least mechanically connecting the auxiliary spindle to a tool turret port of the toolholder turret; driving rotation of such clamped workpiece by torque generated by a drive of a toolholder turret so connected; transferring the clamped workpiece from the first auxiliary spindle to a main spindle of the machining system and / or vice versa; transferring the clamped workpiece from the first auxiliary spindle to a second auxiliary spindle mounted on the same or a different toolholder turret as the first auxiliary spindle; machining the clamped workpiece on at least one auxiliary spindle mounted on the tool holder turret on at least two opposite sides of the clamped workpiece with the aid of a receiving unit; - sequentially machining the workpieces on at least one tool holder turret by allocating the clamped workpieces to a plurality of machining tools and / or additional auxiliary spindles; clamping at least one workpiece on the toolholder turret of the machining system while simultaneously driving at least one machining tool mounted on the toolholder turret; connecting the clamped workpiece with at least one rotating tool of the same or a different toolholder turret to which the auxiliary spindle clamping the workpiece is attached and / or externally driving the rotation of the clamped workpiece by a torque generated by the at least one rotating tool; may include.

[0040] In addition, as mentioned above, the machining system can likewise be configured to automatically or at least semi-automatically perform any of the above-mentioned features, and therefore the present invention can also relate to a computer program product, for example implemented by an internal processor unit connected to the drive system of the claimed machining system, comprising instructions for causing the machining system to perform at least any of the above-mentioned machining steps.

[0041] Moreover, those skilled in the art will appreciate that various adaptations, modifications, and / or combinations of the aspects just described can be constructed. Thus, it should be understood that additional aspects can be practiced other than as specifically described herein. In light of the present disclosure, those skilled in the art will also appreciate that different aspects described herein can be combined to form other aspects of the present disclosure. [Brief description of the drawings]

[0042] [Figure 1] 1 illustrates, by way of example, a schematic framework of a multi-spindle lathe having multiple toolholder turrets arranged around a work spindle that is useful for understanding the present invention. [Figure 2a] 1 shows an exemplary conventional setup of a lathe with one horizontally aligned main spindle and tool holder turret. [Figure 2b] 1 shows an exemplary conventional setup of a lathe with a vertically aligned main spindle and two tool holder turrets. [Figure 3a] 1 shows an exemplary conventional setup of a lathe with a main spindle having a continuous cavity configuration and two tool holder turrets. [Figure 3b] 1 shows an exemplary embodiment of a machining system of the present invention, comprising an auxiliary spindle mounted on a toolholder turret and two machining tools mounted on the toolholder turret and a work spindle, respectively. [Figure 4a] 1 shows, by way of example, another embodiment of the claimed machining system, comprising a second type of auxiliary spindle mounted on the tool holder turret, a machining tool mounted on the second tool holder turret, and two main spindles. [Figure 4b] 4b shows an exemplary machining system with a machining tool for processing the clamped workpiece of the auxiliary spindle from another side. [Figure 5a]1 shows an exemplary embodiment of the claimed machining system, which comprises two auxiliary spindles each mounted on a toolholder turret, and two toolholder turrets carrying machining tools. [Figure 5b] 1 shows an exemplary embodiment of the claimed machining system, which comprises two auxiliary spindles each mounted on a tool holder turret and a machining tool capable of processing two workpieces simultaneously. [Figure 6a] 1 exemplarily illustrates a possible machining operation of a workpiece clamped on an auxiliary spindle using machining tools mounted on a tool holder turret. [Figure 6b] 1 exemplarily shows a possible machining operation of a workpiece clamped on an auxiliary spindle using a machining tool mounted on a fixed object. [Figure 7a] 1 illustrates, by way of example, one embodiment of the claimed machining system, comprising an auxiliary spindle and two rotating tools each mounted on a toolholder turret, with a first rotating tool externally driving the rotation of a clamped workpiece on the auxiliary spindle. [Figure 7b] FIG. 7b exemplarily illustrates the machining system of FIG. 7a, where a second rotating tool externally drives the rotation of the clamped workpiece. [Figure 8a] 1 shows an exemplary embodiment of the claimed machining system consisting of a tool holder turret that simultaneously mounts two auxiliary spindles. [Figure 8b] 8b shows an exemplary cross-sectional perspective view of the toolholder turret of FIG. 8a, which is fitted with two auxiliary spindles; [Figure 8c] 1 shows an exemplary cross-sectional perspective view of a toolholder turret mounting three auxiliary spindles. [Figure 9a] FIG. 2 shows an exemplary cross-sectional perspective view of a tool holder turret holding an unmachined workpiece and a pre-machined workpiece via two auxiliary spindles of a second type. [Figure 9b]9A and 9B show exemplary machining setups utilizing the tool holder turrets of FIGS. 9A and 9C. [Figure 9c] FIG. 2 shows an exemplary cross-sectional perspective view of a tool holder turret holding a pre-machined workpiece and a finished workpiece via two auxiliary spindles of a second type. [Figure 10] 10A and 10B are cross-sectional perspective views of an exemplary embodiment of a clamping mechanism of a receiving unit for mechanically clamping a workpiece onto an auxiliary spindle; [Figure 11] 10A and 10B show exemplarily a cross-sectional perspective view and a second embodiment of a clamping mechanism of the receiving unit for mechanically clamping a workpiece onto an auxiliary spindle; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] In the following, preferred aspects and embodiments will be described in more detail with reference to the accompanying drawings. The same or similar features in different drawings and embodiments will be referred to with like reference numerals. It should be understood that the following detailed description of various preferred aspects and preferred embodiments is not meant as limiting the scope of the present invention.

[0044] 1 shows an exemplary configuration of a machine tool 100, particularly a lathe oriented vertically (with respect to the work floor), useful for understanding the present invention. Specifically, the machine tool 100 shown in this figure includes a framework 110 that holds at least a main spindle 120 on the left side of the machine tool, a counter spindle 140 on the right side, and an intermediate spindle element 130 in the center of the framework 110 that is configured to clamp and position a workpiece W into respective clamping elements 180-182 for machining operations. Moreover, above and below the spindle assemblies 120, 130 and 140, the framework 110 additionally includes a number of turret carrier sides 150 to which are mounted tool holder turrets 160 that include individual rotatable turret heads and a number of tool turret ports 170 for mounting machining tools T onto the tool turret heads.

[0045] Thus, machining of a workpiece W in the illustrated machine tool 100 is handled by mounting the workpiece W on one of the aforementioned spindle elements 120, 130 or 140 and bringing one or more machining tools T mounted on the respective toolholder turret 160 into close proximity thereto. To this end, both the spindle elements 120, 130 and 140 as well as the toolholder turret 160 are configured to move at least horizontally (with respect to the work floor) with the aid of horizontally aligned guide rails 190, and the distance between the respective machining tools T and the clamped workpiece W can be reduced by additionally driving the tool turret heads on which the machining tools are mounted along vertically aligned (with respect to the work floor) guide systems 191 mounted on each toolholder turret 160. In addition, the orientation of the clamped machining tools T can be adjusted by pivoting the tools T along the horizontal turret head axis resulting from the rotation of the corresponding tool turret head.

[0046] As a result, the prior art machine tool 100 allows a satisfactory machining process of a workpiece placed on one of the spindle elements 120, 130 or 140. However, it has also become evident that with this type of machine tool 100 shown in Fig. 1, the actual working space for machining said workpiece W remains rather limited and is usually restricted due to the small accessible area in front of the spindle elements 120, 130 or 140. Moreover, since a large part of the space of the machine tool is conventionally taken up for the adjustment of the machining tools T mounted on the tool holder turret 150, the number of workpieces W that can be processed simultaneously is also limited, leading to a rather inefficient machining process in terms of the utilization of the working space.

[0047] 2a, 2b and 3a are additional setup designs, further highlighting the above problem. Fig. 2a shows the layout of the most simplified version of a typical vertical lathe (relative to the work floor), including at least a horizontally aligned intermediate spindle element 130 capable of clamping a received workpiece W and rotating it along the spindle axis SA by a clamping element 220, and a tool holder turret 200A capable of mounting at least one machining tool T1 and both translating said tool T1 in three directions as well as pivoting said tool along the horizontal turret axis HTA1 to machine the clamped workpiece W.

[0048] In contrast, in Fig. 2b a more advanced lathe 230 is shown, presenting a vertical lathe 230 with an intermediate spindle element 130, vertically aligned and centrally located between two holder turrets 200A and 200C, each including at least a vertical turret axis VTA1 (relative to the work floor) and a horizontal turret axis HTA2 (relative to the work floor) for the rotational movement of the mounted machining tools T1 and T2. Thus, in this system a faster machining process can be achieved, since the clamped workpiece W of the main spindle MS can be processed simultaneously from two sides by the two machining tools T provided by the toolholder turrets 200A and 200C.

[0049] Finally, Fig. 3a shows a third possibility of constructing a lathe 250 similar to that shown in Fig. 2a and 2b, but in contrast to the previous system, the intermediate spindle element 130 is designed as a continuous passage allowing the insertion of the workpiece W so that both sides W1 and W2 of the workpiece W can be machined simultaneously. Conventional lathes using this type of intermediate spindle element 130 therefore usually consist of several toolholder turrets and / or tool spindles to take advantage of the additional machining area released by this kind of spindle element 130. Thus, also in this embodiment, the respective lathe comprises several toolholders, in particular a tool spindle capable of rotating a machining tool T4 around a vertical tool axis VToA1, as well as a toolholder turret 200A on which at least two additional machining tools T1 and T3 are mounted and which pivots said tools T1 and T3 along the horizontal turret axis HTA1 while at the same time allowing at least a rotation of the machining tool T3 around the vertical tool axis VToA2, for example for drilling.

[0050] Thus, distilling the main principles of all these machine tools shown in the aforementioned machining systems, independent of the frameworks and elements used in each of the lathes shown above, the centering of the workpiece W by the spindle elements arranged in a number of tool-holding elements seems to be a central feature shared by many machine tools, so as to maximize the accessibility of said workpiece W for as many machining tools T as logically possible. However, on the contrary, the disadvantage is likewise evident, that in exchange for this particular advantage obtained by building the machine tool around a specific workpiece holder, the actual area for potentially processing the workpiece W is compromised to a relatively small part of the lathe. In other words, since a typical machine tool is usually configured to provide the maximum movement space for the mounted tool elements, such as the tool holder turrets, so as to improve the number of tools available for the individual work spindles, the potential working space in said machine tool is usually not used for machining the workpiece W, but rather to enable the efficient allocation of the respective tools, resulting in an inefficiency of the machine tool in terms of working space utilization. In addition, for this reason, the number of workpieces W that can be processed simultaneously is likewise limited.

[0051] Therefore, the present invention aims to solve the above mentioned problems by using the toolholder turret 200A-200D of the machine tool as additional working space for machining the workpiece W by means of the aforementioned auxiliary spindle AS.

[0052] Now, Fig. 3b shows a first embodiment of a machining system using said auxiliary spindle AS, which may be directly related to the prior art machine tool shown in Fig. 3a and further highlight the advantages associated with the claimed invention. Thus, Fig. 3b shows a machine tool, in particular a lathe, which utilizes, in spite of or in addition to the main spindle MS shown in Fig. 3a, the aforementioned auxiliary spindle AS mounted on a toolholder turret 200B similarly arranged on the machine tool. Here, the auxiliary spindle AS shown in each embodiment is meant to be connected to the toolholder turret 200B by rigidly mounting (e.g. mechanically, electrically or hydraulically) a part of the auxiliary spindle AS, the spindle unit 310, to a turret port of the toolholder turret 200B that is normally used to secure a toolholder to the toolholder turret 200B. Furthermore, in this embodiment, the auxiliary spindle AS is shown to clamp the workpiece W via a receiving unit integrated therein such that two opposite ends W1 and W2 of the workpiece W are exposed for machining and the workpiece W can be rotated at least along a horizontally aligned auxiliary spindle axis ASA defined by the internal structure of the auxiliary spindle AS. Thus, the above described setup described for the auxiliary spindle AS shown in Fig. 3b allows for machining operations on the toolholder turret 200B to be performed similarly or even more efficiently than those performed with the intermediate spindle element 130 shown in Fig. 3a.

[0053] Here, the main advantage of machining a workpiece W on the toolholder turret 200B by means of the auxiliary spindle AS can be attributed, for example, to the additional degree of freedom involved when clamping the workpiece W on the toolholder turret 200B. In comparison to a typical machine tool consisting only of a centrally located workpiece holder, e.g. a main spindle MS, the workpiece W clamped on the toolholder turret 200B via the claimed auxiliary spindle AS can be freely transported and / or adjusted due to the enhanced mobility normally implied by the toolholder turret 200B, thus providing a significantly larger working space area.

[0054] Therefore, also in the machining system shown in Fig. 3b, precise machining of both sides W1 and W2 of the workpiece W can be achieved by accurately allocating said workpiece W to additional, horizontally aligned tool spindles and machining tools T1, T3 and T4, respectively, integrated in the second toolholder turret 200A, using the internal drive mechanism of the mounted toolholder turret 200B. More specifically, in this system, the position of the clamped workpiece W and / or the alignment of its auxiliary spindle axis ASA can be at least alternately varied by translating the mounted toolholder turret 200B in three dimensions and / or pivoting the workpiece W along the turret axis TAW, so that, in contrast to conventional machine tools, the workpiece W can potentially be located anywhere the toolholder turret 200B can reach.

[0055] Based on this, Figures 4a and 4b show another embodiment of the machining system of the claimed invention depicting a second version of the auxiliary spindle AS mounted on the toolholder turret 200B, the receiving unit being configured in such a way as to expose only one side of the workpiece W and rotatably align said workpiece W along the auxiliary spindle axis ASA perpendicular to the horizontal turret axis TAW of the mounted toolholder turret 200B. In this way, machining of the workpiece W can be improved by being able to adjust the auxiliary spindle axis ASA (and thus the tilt angle of the workpiece W) simply by rotating the toolholder turret 200B along the turret axis TAW, allowing for more simplified and precise processing with a machining tool as depicted by T1.

[0056] Also, as seen in this embodiment of the machining system, the production rate of the machine tool can be significantly increased by adding additional workpiece holders by the auxiliary spindle AS to the tool holder turret 200B of a typical machine tool structure consisting of a main spindle MS and a counter spindle CS with respective main and counter spindle axes MSA and CSA, for example, and two tool holder turrets 200A and 200B, as shown in Fig. 4a and Fig. 4b. Exemplarily, in this case, additional machining operations can be performed even when downtime occurs in the processing on the main and counter spindles MS and CS. Furthermore, due to the space removed by the workpiece W on the main and counter spindles MS and CS, more accurate machining can be provided (e.g., both sides of the workpiece W, the left (Fig. 4a) and the right (Fig. 4b) side can be accessed by the machining tool T1), leading to more time-efficient and advanced processing mechanisms of the machine tool. Therefore, it can be recommended to integrate the auxiliary spindle AS into existing machine tools as well, allowing potential upgrade of existing machining operations.

[0057] Figures 5a and 5b show a further embodiment of a machining system using an auxiliary spindle AS of the invention. Here, Figure 5a depicts a machining system including four toolholder turrets 200A-200D evenly distributed in a machine tool, the toolholder turrets 200B and 200D arranged above the toolholder turrets 200A and 200C being fitted with auxiliary spindles AS1 and AS2, the positions of which can be adjusted by translation in three directions and / or by rotation along the turret axes TAW1 and TAW2, respectively. Here, said auxiliary spindles AS1 and AS2 can belong to the same type of auxiliary spindle AS already shown in Figure 3b, correspondingly clamping again two workpieces by their respective receiving units in such a way that the two ends W1 and W2 and W3 and W4 of the workpieces, respectively, are exposed for machining operations. Alternatively, both auxiliary spindles AS1 and AS2 can be configured to clamp two workpieces separately, one from the outlet side of each receiving unit, to further improve the machining process. In addition, two toolholder turrets 200A and 200C arranged below mount at least one machining tool T1 and T2 pivotable by horizontal turret axes HTA1 and HTA2.

[0058] Thus, within the embodiment shown in this figure, more advanced machining operations can be performed on the toolholder turrets 200B and 200D of the respective machining system. In particular, since a plurality of independently movable machining elements with a given number of toolholder turrets 200A-200D are provided in the system, processing steps can also be realized that are performed successively or in parallel, i.e. that can give rise to an automatic production line produced only with the toolholder turret 200B. Thus, the machining system shown in Fig. 5a can be configured, for example, to drive the two toolholder turrets 200B and 200D such that first each of the clamped workpieces is machined separately by one of the machining tools T1 and T2, while in a subsequent machining step both machining tools T1 and T2 are configured to process one working space, for example on both sides W1 and W2 of the workpiece mounted on the toolholder turret 200B. Similarly, more complex machining operations involving any given number of turrets, workpieces or machining tool movements may also be handled by a given or any other machining system presented herein.

[0059] Additionally, Figures 5b, 6a and 6b show further possibilities for potential processing steps that may be used in the machining system of the claimed invention.

[0060] 5b shows a machining system including, in addition to the two toolholder turrets 200B and 200D mounting the workpieces already shown in FIG. 5a, a modified machining tool T9 mounted on the previous toolholder turret 200A consisting of two separate machining components used to simultaneously machine two areas of the workpiece W or two different workpieces W, respectively. Thus, within this embodiment, the machining system utilizing at least two auxiliary spindles AS mounted on two different toolholder turrets 200B and 200D and the aforementioned machining tool T9 can also synchronously machine at least two different sides of the workpiece (e.g., W1 and W2) and / or two different workpieces W using only one machining tool T9 mounted on the third toolholder turret 200A. Of course, in alternative machine systems, the machining tool T6 can also be fixed on a toolholder turret (e.g. 200B) that also mounts an auxiliary spindle AS, or can machine an auxiliary spindle AS arranged on the same or another toolholder turret 200A-200D. Similarly, the number of machining parts mounted on the machining tool T6 does not have to be limited, but can be any number. Thus, the machining tool T9 can also machine any number of workpiece sides W1-W4 or workpieces W simultaneously.

[0061] Fig. 6a shows further exemplary machining mechanisms that can be implemented in the machining system of the present invention. In particular, Fig. 6a(1) to Fig. 6a(2) show the synchronous movement of both the toolholder turret 200B, which mounts the workpiece W via the receiving unit 310 of the auxiliary spindle AS, and the toolholder turret 200A, which holds two machining tools T1 and T2 on different turret ports. In doing so, an improvement of the machining operation on the toolholder turret 200B can be realized by switching the machining tools T1 or T3 when realigning the workpiece W (e.g. when moving the toolholder turret 200B after the end of each machining step), for example by rotating the toolholder turret 200A at least around the horizontal turret axis HTA1 or translating the tool turret 200A, thus enabling a more time-efficient and error-free machining operation. Therefore, since the position of each workpiece W as well as its drive for rotation along the auxiliary spindle axis ASA can be essentially coordinated by, for example, the aforementioned drive system implemented on the corresponding toolholder turret 200B, the above steps are not limited to any particular type of machining tool T, but rather can be implemented for any applicable machining steps required for workpiece processing. Thus, machining on toolholder turrets 200A-200D according to the claimed invention is generally applicable to any type of machining process or sequence thereof.

[0062] Moreover, it should be noted that the machining system of the claimed invention is similarly not limited by only utilizing machining tools T located (i.e., mounted) solely on toolholder turrets 200A-200D. Conversely, any other type of toolholder may be sufficient to produce a suitable machining mechanism due to the increased mobility of the clamped workpiece W provided by the drive system of its corresponding toolholder turret 200A-200D.

[0063] Therefore, Fig. 6b shows a machining system according to the claimed invention, in which the machining tools T7 and T8 for machining any side W1 and W2 of the workpiece clamped on the auxiliary spindle AS are not mounted on the toolholder turrets 200A-200D, but are only fixed on stationary elements 710 and 720, such as rigid frameworks or scaffolds. Therefore, even in such a situation, machining operations can be performed by allocating each working piece W to each of the fixed machining tools T7 and T8 by driving the toolholder turret 220B, on which the auxiliary spindle AS of the working piece W is mounted, thus providing an efficient machining operation even in the case of less accessible machining tools T7 and T8.

[0064] 7a and 7b show another embodiment of the machining system of the present invention and certain machining steps that can be used for process intensification. Here, besides the toolholder turret 200B again providing the workpiece W via the receiving unit 310 of the auxiliary spindle AS, the machining system of this embodiment also includes two rotating tools T5 and T6 mounted on the toolholder turrets 200A and 200C and capable of additionally rotating the workpiece W along the auxiliary spindle axis ASA. More specifically, to do this, said rotating tools T5 and T6 include a fastening element 510 that rigidly interconnects at least one end W1 or W2 of the clamped workpiece W to be processed with the rotating tool T5 or T6 and can function as a chuck that propels the connected workpiece W alone (or in complement to the internal drive of the auxiliary spindle) by generating an aligned torque (e.g. by rotating its body) along the auxiliary spindle axis ASA of the workpiece W. As a result, by the above-mentioned rotary tools T5 and T6, additional rotational forces can be induced to the auxiliary spindle AS of the machining system, improving the accessibility of the auxiliary spindle AS for machining operations requiring same. Also, since the fastening element 510 is permanently connected to at least one side W1 or W2 of the workpiece W during operation of the rotary tools T5 or T6, rotational imbalance of the workpiece W can be reduced, ultimately leading to more stable control of the clamped workpiece W during rotary machining operations.

[0065] Thus, taking advantage of the aforementioned advantages, for example during stabilization of the workpiece W by the rotating tool mounted by the first toolholder turret, at least the other (second) turret can assign its machining tool to improve the workpiece processing, so that the toolholder turrets 200A and 200C of Figures 7a and 7b holding the rotating tools T5 and T6 also include at least one additional machining tool T1 and T2. In addition, if a different machining tool arranged in said first toolholder turret is used in the next machining step, the rotation of the workpiece W can be transferred to the rotating tool of the other (second) toolholder turret by simply assigning the respective rotating tool of the second toolholder turret to the workpiece W via the rotating turret axes HTA3 and HTA4 provided for each toolholder turret 200A and 200C.

[0066] 8a shows a further embodiment of the machining system of the present invention, comprising at least one toolholder turret 800A mounting at least two auxiliary spindles AS1 and AS2, said toolholder turret 800A being arranged to move each of the auxiliary spindles 810A and 810B by rotating at least along a turret axis TAW so that different workpieces RWP and FWP clamped in the receiving units 810A and 810B of the auxiliary spindles AS1 and AS2, respectively, can be individually positioned in the system. The illustrated turret arrangement thus produces an efficient and space-saving machining mechanism.

[0067] As an example, the machining system shown in Fig. 8a allows the insertion of a workpiece RWP into the receiving unit 810A of the first auxiliary spindle AS1, for example to increase the accessibility for an assistant to introduce the unmachined workpiece RWP into the respective machining system. Alternatively, the introduction can also be performed automatically, for example by transferring the workpiece RWP from a storage or spindle similarly arranged in the system. Then, following the clamping of the corresponding unmachined workpiece RWP in the receiving unit 810A of the auxiliary spindle AS1, the tool holder turret 800A is configured to pivot the clamped workpiece RWP by rotating its corresponding turret head at least along the turret axis TAW so as to assign the unmachined workpiece RWP onto the machining tool T1 for the machining operation. Finally, after completing the machining process with machining tool T1 (or any additional machining elements), the completed workpiece FWP can be pivoted again by tool holder turret 800A to extract it or pass it to a subsequent machining position, enabling a highly efficient machining line in terms of both space efficiency and machining accuracy.

[0068] Further, Fig. 8b shows a cross-sectional image of the toolholder turret 800A depicted in Fig. 8a. Thus, as seen in the dashed lines added to Fig. 8b, the two auxiliary spindles 810A and 810B are arranged coaxially with respect to the vertical centerline VTAT1 of the toolholder turret 800A (or perpendicularly with respect to the horizontal centerline HTAT1, respectively) so that the positions of the unmachined workpiece RWP and the finished workpiece FWP can be easily swapped by rotating the toolholder turret 800A 180 degrees along the turret axis TAW. Here, of course, the corresponding toolholder turret of the claimed machining system is not limited by only mounting two auxiliary spindles AS1 and AS2, but rather can hold any number of auxiliary spindles possible by its inherent turret ports.

[0069] 8c can be used as an alternative embodiment 800B of the toolholder turret 800A shown in Fig. 8a and 8b, in which an additional auxiliary spindle AS3 is mounted in a triangular arrangement. This arrangement allows, for example, to integrate additional machining steps into the aforementioned process line, producing a pre-machined workpiece MWP clamped in the receiving unit 810C of the auxiliary spindle AS3. Thus, even more advanced machining processes can be achieved with the given embodiment.

[0070] Further based on the above-mentioned embodiment, Figures 9a-9c show another machining mechanism that can be performed by the machining system of the claimed invention. Here, as in the embodiment shown in Figure 5a, the corresponding machining system comprises four toolholder turrets 900A-900D, two toolholder turrets 900A and 900B are configured to mount two auxiliary spindles AS4-AS7, respectively, of the type already shown in Figures 4a and 4b, while the toolholder turrets 900C and 900D mount machining tools T1 and T2, respectively. In addition, Figures 9a and 9c again show cross-sectional images of the respective toolholder turrets 900A and 900B with the auxiliary spindles AS4-AS7, which are likewise aligned coaxially with respect to the vertical centre line VTAT3 or VTAT4 (or perpendicularly to the horizontal centre line HTAT3 or HTAT4, respectively). The terms horizontal and vertical relate to the arrangement with respect to the work floor.

[0071] Thus, within the described machining system, a production line is shown that additionally uses a transfer process of the workpiece W between the auxiliary spindles AS4-AS7. More specifically, in this given embodiment, the operating sequence is such that, in order to be able to start the production line, the machining mechanism first inserts and clamps the unmachined workpiece RWP in the first auxiliary spindle AS4 of the first toolholder turret 900A. Then, as a second step, by pivoting the auxiliary spindle via a rotation of the toolholder turret 900A along the turret axis TAW1, the unmachined workpiece RWP can be assigned to the first machining tool T1, which finally allows pre-machining of the clamped unmachined workpiece RWP and thus the production of the pre-machined workpiece MWP. Further, to continue the processing mechanism, the pre-machined workpiece MVP is then transferred from the aforementioned auxiliary spindle AS4 to the auxiliary spindle AS6 mounted on the second toolholder turret 900B to allow machining via the second machining tool T2, and the production line is finished by once again pivoting the finalized workpiece FWP via rotation of the toolholder turret 900B along the turret axis TAW2 to allow extraction of the workpiece and / or further processing by external machining elements.

[0072] Here, the action of transferring the pre-machined workpiece MWP can be performed exemplarily by receiving the workpiece MWP and bringing it close to the auxiliary spindle AS6, in particular by precisely moving the toolholder turret 900A towards said auxiliary spindle AS6, which allows it to additionally clamp an available portion of the workpiece while simultaneously releasing it from its previous fixation. Alternatively, external transfer elements such as workpiece grabbers can also be used, so that a reliable transfer of the workpiece can be achieved.

[0073] Finally, in figures 10 and 11 two preferred embodiments of clamping mechanisms for mechanically clamping the respective workpiece W to the receiving units 311A ​​and 311B of the auxiliary spindle AS are shown, whereby the respective mechanisms can be driven manually or (semi-)automatically, for example by the internal drive system of the toolholder turret to which the auxiliary spindle AS is mounted.

[0074] 10 illustrates the first mechanism by depicting a cross-sectional view of the receiving unit 311A ​​along the aforementioned auxiliary spindle axis ASA. In particular, in this embodiment, the receiving unit 311A ​​consists of a cavity 1050 used to insert the respective workpiece W into the receiving unit 311A, and a mechanically adjustable body 1005 built around the aforementioned cavity 1050. Here, in order to clamp the respective workpiece W in the receiving unit 310A, the body 1005 further has a bottom 1010 and a top component 1040 connected via a screw element 1030, and a wedge-shaped element 1020 disposed therebetween, including a wedge-shaped portion 1020A at one end, which is straight on the side facing the bottom component 1010, and an increased diameter on the side facing the top component 1040, and a straight portion 1020B at the other end. In addition, to allow the wedge element 1020 to slidably fit between the bottom 1010 of the body 1005 and the top component 1040, the gap associated with the wedge-shaped portion 1020A between the top 1040 and the bottom component 1010 is similarly constructed to be wedge-shaped, while at the other end, the distance between the top 1040 and the bottom component 1010 associated with the straight portion 1020B remains constant.

[0075] Therefore, in order to fix the inserted workpiece W by mechanically clamping it onto the receiving unit 311A, the body 1005 is constructed in such a way that by forcing the wedge-shaped portion 1020A into its corresponding gap constructed between the top 1040 and the bottom component 1010, the wedge-shaped portion 1020A eventually reaches a point where it cannot move any further, also due to the size of the wedge-shaped gap, thus generating a pressure perpendicular to the contact area between the wedge-shaped portion 1020A and the bottom 1010 and top components 1040 of the body 1005, respectively. As a result, in a given embodiment, the contact area between the wedge-shaped portion 1020A and the bottom component 1010 is configured to be parallel to the inner surface of the body 1005, so that the pressure generated by the above-mentioned pressing of the wedge-shaped portion 1020A results in a radial pressing movement of the bottom component 1010, thereby firmly pressing the inner surface of the body 1005 against the inserted workpiece W, thereby enabling mechanical fixation by clamping.

[0076] FIG. 11, in contrast, shows a second mechanism for securing the workpiece W to the receiving unit 310B, which utilizes a spring mechanism 1150 to transfer the aforementioned pressure onto the inserted workpiece W, as compared to the wedge element 1020 shown in FIG. 10 .

[0077] More specifically, in this case, the body 1005 of the receiving unit 311B also has a bottom component 1110 and a top component 1140, and the top component 1140 can be further divided into a force transmission part 1130 slidably attached to the upper surface of the bottom component 1110, and a reaction part 1120 arranged above the force transmission part 1130 and horizontally connected thereto via a spring 1150. In addition, the force transmission part 1130 of the top component 1140 can be further connected to a pressing block 1160 via a screw 1030, and by introducing the screw 1030 into the transmission part 1130, a part of the pressing block 1160 can press the reaction part 1120, resulting in a displacement of the reaction part 1120 coaxially with the longitudinal axis of the coil spring 1150.

[0078] Therefore, to generate the aforementioned pressure in this embodiment, the screw 1030 can first be further introduced into the force transmission part 1130, which leads to moving the pressing block towards the reaction part 1120, and when contacted, a pressing force Fp is transmitted to it. Then, as a result of the aforementioned pressing force Fp, the reaction part 1120 can be displaced, which results in the compression of the spring 1150 arranged between the reaction part 1120 and the force transmission part 1130, which in turn presses the force transmission part 1130 onto the bottom component 1110 of the receiving unit 310B, and again generates an adjustable stable pressure on the inner surface of the receiving unit 310B.

[0079] Thus, the above described embodiments make it possible to show that the use of auxiliary spindles implemented in different kinds of machining systems allows highly adaptable and efficient machining operations to be performed on at least one toolholder turret. Moreover, since said machining operations can be performed independently and / or in addition to the conventional work of the corresponding machine tool, for example on the work spindle, it is clear that the claimed invention can lead to significant improvements for machine tools in terms of space efficiency, operating time and general adaptability of the system.

[0080] Finally, while several exemplary embodiments and / or aspects have been described and illustrated in the accompanying drawings, it should also be noted again that such embodiments and aspects are merely illustrative of the broad invention and are not limiting thereto, and that embodiments of the invention are not limited to the specific constructions and arrangements shown and described, as various other modifications, combinations, omissions, modifications, and substitutions are possible in addition to those described in the preceding sections.

[0081] Moreover, those skilled in the art will appreciate that various adaptations, modifications, and / or combinations of the presently described embodiments can be made without departing from the scope of the present disclosure. In light of the present disclosure, those skilled in the art will also appreciate that different embodiments of the present invention described herein can be combined to form other embodiments of the present invention. Thus, it should be understood that the present invention can be practiced other than as specifically described herein.

Claims

1. A machining system, particularly a lathe, for machining at least one workpiece (W), comprising at least one toolholder turret (200A - 200D) for holding a plurality of tools (T1 - T4) for machining operations and at least one auxiliary spindle (AS) mounted on the toolholder turret (200A - 200D). In a machining method for machining at least one workpiece (W), the machining method is characterized in that the auxiliary spindle (AS) includes at least a receiving unit (311A, 311B) for receiving the workpiece (W) for machining operations, On the toolholder turret (200A - 200D), clamping the workpiece (W) by the receiving unit (311A, 311B) of the auxiliary spindle (AS); Rotating the clamped workpiece (W) along the auxiliary spindle axis (ASA) to machine the clamped workpiece (W); The machining method including the above steps.

2. Machining the clamped workpiece (W) on the toolholder turret (200A - 200D) by tools (T1 - T4) mounted on at least one toolholder turret (200A - 200D) and / or tools (T1 - T4) mounted on a main spindle (MS) implemented in the machining system; The machining method according to Claim 1, further including the above step.

3. Pivoting the clamped workpiece (W) by rotating the toolholder turret (200A - 200D) on which the auxiliary spindle (AS) is mounted along the turret axis (TAW); Moving the clamped workpiece (W) by translating the toolholder turret (200A - 200D) on which the auxiliary spindle (AS) is mounted in at least one of three directions; The machining method according to Claim 1, further including the above steps.

4. Connecting the auxiliary spindle (AS) to the drive system of the toolholder turret (200A - 200D) by mechanically connecting the auxiliary spindle (AS) to a tool turret port of the toolholder turret (200A - 200D); Driving the rotation of the clamped workpiece (W) by torque generated by driving at least one tool holder turret (200A - 200D); The machining method according to claim 1, further comprising.

5. Transferring the clamped workpiece (W) from the first auxiliary spindle (AS1) to the main spindle (MS) of the machining system and / or vice versa; Transferring the clamped workpiece (W) from the first auxiliary spindle (AS1) to a second auxiliary spindle (AS2) mounted on the same or a different tool holder turret (200A - 200D) as the first auxiliary spindle (AS1); Further comprising; And / or; While driving the machining tools (T1 - T4) mounted on the tool holder turret (200A - 200D), further comprising the step of simultaneously clamping at least one workpiece (W) on the tool holder turret (200A - 200D) of the machining system; And / or; Connecting the clamped workpiece (W) to at least one rotary tool (T5, T6) of the same or a different tool holder turret (200A - 200D) on which the auxiliary spindle (AS) for clamping the workpiece (W) is mounted; Driving the rotation of the externally clamped workpiece (W) by the torque generated by the at least one rotary tool (T5, T6); The machining method according to claim 1, further comprising.

6. A computer program comprising instructions to cause the machining system according to claim 1 to perform the steps according to claim 1.

7. An auxiliary spindle (AS) for clamping at least one workpiece (W) on a tool holder turret (200A - 200D), in particular a tool holder turret (200A - 200D) of a lathe (230), for a machining operation, At least one spindle unit (310) that can be mounted on the tool turret port of the tool holder turret (200A - 200D) and is configured to receive a workpiece (W) and perform a machining operation on the received workpiece (W) on the tool holder turret Comprising; The spindle unit (310) further includes at least a receiving unit (311A, 311B) configured to clamp the workpiece (W) onto the auxiliary spindle (AS). The auxiliary spindle (AS). **Claim 8** The auxiliary spindle (AS) is configured to rotate the clamped workpiece (W) along the auxiliary spindle axis (ASA) for machining the clamped workpiece (W) on the tool holder turrets (200A - 200D), and / or The auxiliary spindle (AS) is configured such that the spindle unit (310) is mounted on at least one tool holder turret (200A - 200D) to physically connect the auxiliary spindle (AS) to the drive system of the tool holder turret (200A - 200D), whereby the auxiliary spindle (AS) can be controlled by the turret drive system. The auxiliary spindle (AS) according to claim 7. **Claim 9** The spindle unit (310) is configured to clamp the workpiece (W) at at least one contact position and expose at least two opposing ends (W1, W2) of the clamped workpiece (W) for machining operations, and / or the spindle unit (310) includes a sleeve that can be controlled to clamp the workpiece (W), The sleeve is configured to align the fixed workpiece (W) coaxially with the auxiliary spindle axis (ASA). The auxiliary spindle (AS) according to claim 7. **Claim 10** The spindle unit (310) includes at least one chuck that can be controlled to fixedly clamp the workpiece (W), the at least one chuck is configured to align the clamped workpiece (W) coaxially with the auxiliary spindle axis (ASA), and the at least one chuck includes a jaw that is configured to move independently to firmly hold an irregularly shaped workpiece (W). The auxiliary spindle (AS) according to claim 7. **Claim 11** A machining system for machining at least one workpiece (W), in particular a lathe (230), At least one tool holder turret (200A - 200D) for mounting a plurality of tools (T1 - T4) on at least one tool turret port, particularly for live tooling, and The auxiliary spindle (AS) according to claim 9 mounted on the at least one tool holder turret (200A - 200D) or another tool holder turret (200A - 200D) implemented in the machining system, and A machining system comprising the same.

12. The workpiece (W) clamped by the receiving units (311A, 311B) of the auxiliary spindle (AS) can be rotated along the auxiliary spindle axis (ASA), The machining system according to claim 11, wherein the rotation of the workpiece (W) is driven by at least the torque generated by the drive of the tool holder turret (200A - 200D).

13. The machining system is configured to machine the workpiece (W) on the tool holder turret (200A - 200D) by clamping the workpiece (W) onto the receiving unit of the auxiliary spindle (AS), by at least one machining tool (T1 - T4) mounted on the main spindle (MS) of the machining system and / or by at least one machining tool (T1 - T4) mounted on one of the tool holder turrets (200A - 200D) of the machining system, and / or The tool holder turret (200A - 200D) on which the auxiliary spindle (AS) is mounted is configured to adjust the position of the workpiece (W) clamped by the receiving unit of the auxiliary spindle (AS) and / or the direction of the auxiliary spindle axis (ASA) by at least rotational movement and / or translational movement along at least the turret axis (TAW). The machining system according to claim 11.

14. The tool holder turret (200A - 200D) on which at least one auxiliary spindle (AS) is mounted is configured to mount at least one additional machining tool (T1 - T4), and / or The machining system according to claim 11, wherein the tool holder turret (200A to 200D) on which the at least one auxiliary spindle (AS) is mounted arranges a workpiece (W) clamped on the auxiliary spindle (AS) and performs at least a machining operation on the workpiece (W) on the tool holder turret (200A to 200D), and is configured to arrange at least one tool (T1 to T4) for machining the workpiece (W).

15. The machining system includes at least first and second tool holder turrets (200A to 200D) on which at least a first auxiliary spindle (AS1) and a second auxiliary spindle (AS2) are respectively mounted. The machining system is configured to transfer a workpiece (W) clamped by a receiving unit of the first auxiliary spindle (AS1) of the first tool holder turret (200A to 200D) to a receiving unit of the second auxiliary spindle (AS2) of the second tool holder turret (200A to 200D) by the movement of the at least two tool holder turrets (200A to 200D), and / or At least one tool holder turret (200A to 200D) of the machining system is configured to mount at least two auxiliary spindles (AS1 to AS6) capable of individually clamping a workpiece (W) for a machining process, and The machining system is configured to independently machine each of the clamped workpieces (W) by at least one machining tool (T1 to T4) clamped to the main spindle (MS) of the machining system and / or at least one machining tool (T1 to T4) mounted on one of the tool holder turrets (200A to 200D) of the machining system.

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