Clamping device and method for handling a workpiece

Abstract

Clamping device (10) for clamping a workpiece carrier (12) on a machine tool (46) with a tool spindle (45), wherein the clamping device (10) comprises: - a base (14) with a support surface (15) for arranging a workpiece carrier (12), - an actuating device (23) arranged at the base (14), which has an externally accessible control element (24) formed by a control ring (25), which is movable along a path about a vertical axis (H) passing through the support surface (15) between a first position (P1) and a second position (P2) by means of the tool spindle (45) of the machine tool (46), wherein the control element (24) has a coupling device (37) which is configured to be detachably connected to a feedback device (38) of a spindle adapter (39), which is configured to be held by the tool spindle (45) of the machine tool (46), so that the tool spindle (45) can engage by means of the spindle adapter (39) and a rotational movement of the spindle adapter (39) leads to a movement of the control element (24) along the path between the first position (P1) and the second position (P2),wherein the clamping device (10) is in a release state that releases the workpiece carrier (12) when the operating element (24) is in the first position (P1), wherein the clamping device (10) is in a clamping state that holds the workpiece carrier (12) when the operating element (24) is in the second position (P2).

Description

[0001] The invention relates to a clamping device and a method for handling a workpiece, in particular for automatic workpiece clamping or automatic workpiece changing in a machine tool.

[0002] EP 2 269 770 A1 discloses storing tools and workpieces together in a magazine. The tools can be removed from the magazine using the tool spindle and used for machining. The workpieces are provided with a corresponding interface or adapter so that the workpiece can be accommodated in the tool spindle originally intended for the tool. This allows, for example, the workpiece to be driven in rotation by the tool spindle and machined with a stationary tool.

[0003] A similar principle is also described in EP 0 215 209 A2. There, the adapter, which allows a workpiece to be removed from the magazine via the tool spindle, is removed and replaced when the workpiece is clamped in a clamping device. The workpiece can then be machined.

[0004] WO 2021 / 013899 A1 discloses a method for handling workpieces that can be stored in a cocoon together with tools in a magazine. The cocoon consists of a carrier and a base. The workpiece is arranged on the base. The carrier can be gripped by the tool spindle, and the cocoon can be arranged in the machine tool. By a relative movement between the carrier and the base of the cocoon, a detachable connection between the carrier and the base can be released, thereby opening the cocoon. The tool spindle can then deposit the carrier, pick up a tool, and machine the workpiece arranged on the base.

[0005] DE 10 2014 112 845 A1 describes a clamping device comprising a clamping block designed like a vice. The vice can be clamped in a base plate using a zero-point clamping system. For this purpose, the vice is provided with retaining bolts, each of which can be inserted into a corresponding hole in the base plate. A clamping screw is provided in the base plate as an operating element, by means of which clamping bodies can be moved into a clamping position, in which they act upon the retaining bolts. This allows the clamping block to be clamped firmly to the base plate.

[0006] DE 10 2019 100 089 B3 discloses a chuck in which a base body is mounted radially to a central axis, with clamping jaws movable toward or away from the central axis. Such chucks are used to clamp workpieces along the central axis, for example, in lathes. An actuating mechanism is used to move the clamping jaws, allowing a carrier ring to be rotated around the central axis.

[0007] DE 10 2012 219 140 A1 discloses a swivel change system. The system has a swivel part that can be swiveled between different swivel positions. A change system can be attached to the swivel part. The change system is designed to hold a retaining bolt by means of clamping slides that can be moved radially to the retaining bolt. The swivel part, which supports the change system, can be actuated via a rack and pinion drive. The rack of the rack and pinion drive can be moved by applying pressure via a drive piston.

[0008] WO 2020 / 083416 A1 discloses a device for machining a workpiece. The device has a robot arm with two grippers and a screwing tool. A clamping device used to clamp a workpiece can be tightened or released via a square drive using the screwing tool.

[0009] US 3,429,543 A relates to a mounting device for a camera, for example, for use in a laboratory or photo studio. A plate can be screwed to the camera and clamped in a clamping device by operating an operating lever.

[0010] Based on the known prior art, it is an object of the present invention to provide a clamping device and a method to simplify the handling of a workpiece and in particular clamping and releasing the workpiece in the machine tool.

[0011] This object is achieved by a clamping device having the features of patent claim 1 and a method having the features of patent claim 10.

[0012] The clamping device according to the invention is designed for clamping a workpiece carrier to a machine tool. The clamping device has a base with a support surface. The support surface is designed so that the workpiece carrier can be placed thereon and held there. In particular, the workpiece carrier is pulled against the support surface with a tensile force. The support surface is preferably planar.

[0013] The base can have several holes for receiving retaining bolts arranged on the workpiece carrier. The retaining bolts each engage in a hole on the base when the workpiece carrier is positioned on the clamping device.

[0014] The clamping device has an actuating device with an operating element. The operating element is movable along a path around a vertical axis, for example, rotatable or pivotable. The path has a first position and a second position and can, for example, extend between these positions. The path can, for example, be a circular path or a circular arc around the vertical axis. The vertical axis passes through the support surface and can represent a central axis of the base. The vertical axis can pass through the geometric center of the support surface.

[0015] The clamping device is in a release state, releasing the workpiece carrier, when the operating element is in the first position. However, if the operating element is in the second position, the clamping device is in a clamped state, holding the workpiece carrier to the support surface.

[0016] In particular, the actuating device can have clamping bodies coupled for movement to the operating element, with a clamping body assigned to each hole. In the released state, the clamping bodies are in a position that allows the insertion and removal of a retaining pin into or from a hole in the base. In the clamped state of the clamping device, each retaining pin is acted upon by an associated clamping body and retained in the hole or drawn into the hole, so that the workpiece carrier is held to the base or the support surface.

[0017] Because the operating element is movable on a path around the vertical axis between the first position and the second position, the operating element can be operated very easily by moving a tool spindle of the machine tool. For example, the tool spindle can cause a rotary movement around the spindle axis in order to move the operating element from the first position to the second position or vice versa from the second position to the first position. A suitable device is preferably accommodated in the tool spindle for this purpose, for example a spindle adapter or another operating tool by means of which a movement along the path around the vertical axis can be carried out. It is advantageous if, in order to operate the operating element, the vertical axis of the base or the clamping device and the spindle axis of the tool spindle coincide during the movement of the operating element along the path.

[0018] Such a clamping device can be used in particular for the automatic clamping and release of workpieces in a machine tool. For this purpose, the clamping device can be arranged in an existing machine clamping device of the machine tool and held there. The machine clamping device does not need to be capable of automated or controlled clamping and release for this purpose. The clamping and release of the workpiece carrier is carried out by the clamping device according to the invention in that the operating element is moved into the first position or the second position by an operating movement of the tool spindle. The clamping device can always be clamped in the machine clamping device of the machine tool during workpiece machining and workpiece changing.

[0019] In a preferred embodiment, the actuating device has at least one slider that bears directly or indirectly against the operating element. The at least one slider is mounted so as to be displaceable along its extension direction. It can be moved into different positions by moving the operating element. The at least one slider is motion-coupled to several or all of the clamping bodies. Conversely, at least each clamping body is motion-coupled to one of the sliders.

[0020] To convert the movement of the operating element along the path into a linear movement of the slide, at least one cam follower arrangement can be used, each with a cam surface which has an eccentric rather than a concentric course relative to the vertical axis of the clamping device. For example, the at least one cam surface can extend around the vertical axis along at least a section of a spiral turn or along a complete spiral turn. In particular, the cam surface extends at most along one complete spiral turn. Viewed around the vertical axis, different points on the at least one cam surface have different distances from the vertical axis. The course of the cam surface is curved, with the curvature varying. The cam surface can face towards the vertical axis or away from the vertical axis.

[0021] In one embodiment, the at least one curved surface is provided on the operating element. The at least one slider can rest against the respectively assigned curved surface. The curved surface faces the slider and the vertical axis. In another embodiment, the at least one curved surface can be provided on the at least one slider facing away from the vertical axis, in which case the operating element rests against the at least one curved surface. In this embodiment, the number of curved surfaces corresponds to the number of sliders present.

[0022] In order to minimize the torque required to rotate the operating element around the vertical axis or the force required to move the operating element along the path, the friction during the movement of the operating element or of the at least one slider along the cam surface can be reduced. In one embodiment, a rolling bearing contact can be realized for this purpose between the operating element or the at least one slider and the respectively associated cam surface. For example, at least one rolling element can be in rolling contact with each existing cam surface. Depending on the embodiment, the rolling element can be rotatably mounted on the operating element or on the slider.

[0023] The at least one slider is, in particular, motion-coupled to the clamping bodies of the actuating device. Any form of mechanical transmission can be used for this purpose. In one embodiment, the motion coupling is achieved via a wedge-face arrangement or a wedge-face transmission. Other transmission means, such as gears, racks, etc., can also be used for motion coupling.

[0024] The actuating device can have at least one compensating unit. The at least one compensating unit can be arranged anywhere in the force transmission path between the operating element and each of the clamping bodies. If several separate force transmission paths are present, each force transmission path has at least one compensating unit. The at least one compensating unit is designed to limit the clamping force that can be transmitted from the clamping bodies to the retaining bolts. This allows for uniform clamping and at least partially compensates for possible asymmetrical force transmissions to the clamping bodies due to tolerances in component manufacturing and assembly.

[0025] In one embodiment, each compensation unit has at least one elastically deformable body, for example a spiral spring and / or a disc spring and / or a plastic body, etc. For example, each slider of the actuating device can have a compensation unit or at least one elastically deformable body. In one embodiment, the slider is split in two and the compensation unit is arranged between the two slider parts which are mounted so as to be movable relative to one another. The at least one compensation unit or the at least one elastically deformable body is designed to deform elastically when the force in the respective force transmission path increases significantly. For example, two separate slider parts can deform due to the elastic deformation of the compensation unit orof the at least one elastic body relative to each other, so that a further increase in clamping force transmitted via the clamping bodies is at least reduced.

[0026] The control element is formed by a control ring aligned with the vertical axis. The control ring can enclose the support surface. Alternatively, the control element could also be a ring segment or another arcuate element extending around the vertical axis in an angular range of less than 360°.

[0027] A spindle adapter can be used to transport the workpiece carrier with the workpiece. The spindle adapter is designed to be held in the tool spindle of the machine tool and can have a spindle interface for this purpose, for example a taper such as a Morse taper, steep taper, or hollow shank taper. In particular, the spindle adapter is designed to be detachably connected to the workpiece carrier. A workpiece assembly comprising the spindle adapter, the workpiece carrier, and the workpiece arranged thereon can thus be transported by means of the tool spindle, in particular from a storage location to the clamping device or vice versa. Thus, not only the clamping of the workpiece carrier but also its transport is very easily possible by controlling the movement of the tool spindle.

[0028] The operating element has a coupling device designed to be detachably connected to a counter-coupling device of the spindle adapter. The detachable connection is positively locked in the direction of movement of the operating element and preferably rotationally fixed, so that a rotational movement of the spindle adapter results in a movement of the operating element along the path between the first position and the second position.

[0029] Preferably, the connection between the coupling device and the counter-coupling device is established or released by a movement parallel to the vertical axis.

[0030] For example, the coupling device can have at least one projection extending in the direction of the vertical axis, which engages in a recess in the counter-coupling device when the connection is established. In a direction around the spindle axis, the recess on the spindle adapter can have a dimension that corresponds to the dimension of the projection, or be larger in order to enable a rotational movement of the spindle adapter around the spindle axis without any movement of the operating element. Additionally or alternatively, the counter-coupling device can also have a projection which engages in a recess in the coupling device when the connection is established. This detachable connection can be established or released very easily by moving the tool spindle or the spindle adapter parallel to the vertical axis.

[0031] It is advantageous if the spindle axis of the tool spindle coincides with the vertical axis of the clamping device when the connection between the coupling device and the counter-coupling device is established.

[0032] The invention also relates to a method for handling a workpiece. This method is particularly suitable for machine tools that do not have complex grippers or manipulators for automatic tool and / or workpiece changes. The method according to the invention enables tool and workpiece handling using the tool spindle of the machine tool.

[0033] The tool spindle can be moved relative to the clamping device in several degrees of freedom, for example, in two or three linear degrees of freedom. Additionally or alternatively, the tool spindle can also be moved relative to the clamping device in one or more rotational degrees of freedom. The tool spindle can also have a spindle mount that can be rotated about a spindle axis.

[0034] The machine tool has storage locations for workpieces and tools, for example a magazine unit for workpieces and tools. The magazine unit can be formed by a single common magazine or several separate magazines. The storage locations of the magazine unit can be movable relative to a machine base of the machine tool. Additionally or alternatively, at least one storage location for a tool or a workpiece can be immobile relative to the machine base of the machine tool. The magazine unit can have one or more chain magazines and / or revolver magazines and / or other magazines. The magazine unit can have several movable magazine locations and can, in particular, be designed to bring one or more of the existing magazine locations into a change position in which the relevant magazine location(s) can be reached by the tool spindle of the machine tool.For example, a tool or workpiece stored there can be removed directly from the magazine unit by the tool spindle, without the need for grippers and / or manipulators.

[0035] A workpiece to be machined can be stored at at least one of the storage locations. Each workpiece to be machined is held on a workpiece carrier. The workpiece carrier has a spindle adapter. The spindle adapter can be permanently or detachably connected to the workpiece carrier. The spindle adapter has an interface by means of which the spindle adapter can be directly accommodated by the tool spindle of the machine tool. This is the same interface that is also present on the tools for attaching the tools to the tool spindle. The interface can be, for example, a taper, such as a Morse taper, steep taper, or hollow shank taper.

[0036] At least one tool is also provided at at least one of the storage locations, which tool has the interface for being received in the tool spindle.

[0037] A clamping device is arranged in the machine tool and in particular on a machine clamping device of the machine tool. The clamping device is designed to clamp the workpiece carrier with the workpiece in the machine tool. The clamping device has an operating element for bringing the clamping device into a clamped state. In particular, the clamping device can be brought from the clamped state into a released state again by means of the operating element. In one embodiment, the operating element can be rotated about an axis of rotation. Preferably, the operating element is pivoted with a rotation or pivot angle that is less than 360° and more preferably a maximum of 180° or a maximum of 90° in order to bring the clamping device from the released state into the clamped state or vice versa.

[0038] The clamping device used in the method can correspond to one or more of the exemplary embodiments described above. For example, the axis of rotation can be formed by the vertical axis of the clamping device according to the invention. However, other, modified configurations of the clamping device can also be used in the method according to the invention.

[0039] The tool spindle uses the spindle adapter to pick up a workpiece carrier containing a workpiece to be machined from one of the storage locations and transports the workpiece carrier to the clamping device. The workpiece carrier is placed on the support surface. Subsequently, during or after the connection between the spindle adapter and the workpiece carrier is released, the operating element is moved from the first position to the second position by moving the tool spindle, so that the clamping device is switched from the released state to the clamped state. The workpiece carrier is now clamped or held on the clamping device. The operating element is operated in particular using the spindle adapter held in the tool spindle and preferably by rotating the spindle adapter around the spindle axis.

[0040] The connection between the spindle adapter and the tool spindle can then be released. For example, the spindle adapter can be placed in a free storage location, preferably in a magazine unit. The tool spindle can then accommodate a tool, and work can be performed on the workpiece held in the clamping device by the workpiece carrier, for example, machining using a machining tool or measuring at least one dimension of the workpiece using a measuring tool.

[0041] In clamping device designs where operation of the operating element is not possible as long as the tool spindle holds the spindle adapter, the connection between the spindle adapter and the tool spindle can first be released after the workpiece carrier has been arranged on the clamping device. Subsequently, by a suitable operating movement of the tool spindle, the operating element can be moved from the first position to the second position, thus switching the clamping device into the clamped state. For example, the spindle adapter can be placed in a free storage location before switching the clamping device into the clamped state, and the connection to the tool spindle can be released there. The tool spindle can then move the operating element.

[0042] When using a machining tool, the workpiece can be machined, for example, by cutting. The machining tool can, for example, be driven in rotation about the spindle axis. Thus, the workpiece can be machined by drilling and / or milling and / or grinding, or in any other way using the tool. Additionally or alternatively, a measuring tool can be arranged at one of the workstations, with which the machined workpiece can be measured in one or more dimensions. The measuring tool can, for example, be a non-contact or contact probe.

[0043] In principle, any type of tool can be mounted and used to perform work on the workpiece. Tool changes can also be performed, and multiple tools can be used sequentially to perform work on the workpiece.

[0044] Thus, all operating processes can be performed via the tool spindle. Additional devices for transporting tools or workpieces between the tool spindle and the storage locations (e.g., in the magazine unit) or for operating the clamping device are not required. According to the invention, the clamping and release of the workpiece carrier can be achieved by operating the clamping device via the tool spindle. The machine tool does not require a controllable machine clamping device that can be switched between the clamped and released states, for example, by electric motor, pneumatically, or hydraulically. According to the invention, automated machining processes with automatic tool changes and automatic workpiece changes can therefore be performed exclusively via the machine tool's tool spindle. The method is suitable, for example, for the automatic machining of identical workpieces in small series production.

[0045] It is advantageous if the connection between the spindle adapter and the workpiece carrier is detachable, for example, a detachable locking connection. This makes it possible to release the connection between the spindle adapter and the workpiece carrier and store the spindle adapter in the magazine unit. Accessibility to the workpiece can be improved by removing the spindle adapter. The connection between the spindle adapter and the workpiece carrier can be released by a relative movement between the spindle adapter and the workpiece carrier, in particular by a rotational movement around the spindle axis.

[0046] It is advantageous if, during or after the release of the connection between the spindle adapter and the workpiece carrier, the operating element is moved from a first position to a second position by a preferably uninterrupted relative movement, thereby switching the clamping device from the released state to the clamped state. This movement can, in particular, be a continuous rotational movement around the spindle axis. The spindle adapter preferably engages the operating element.

[0047] It is preferred if, after completing work on the workpiece, the tool is placed at one of the storage locations, and then the operating element of the clamping device is actuated using the tool spindle to bring the clamping device into the release state. In particular, a rotational movement about a rotational axis of the operating element can occur. The direction of movement, for example, the sense of rotation, for switching the clamping device from the clamped state to the release state is opposite to the direction of movement of the operating element in which the clamping device can be brought from the release state to the clamped state.

[0048] In particular, switching the clamping device to the release state can be carried out by moving the operating element from the second position to the first position through a corresponding movement of the tool spindle, in particular by a rotational movement about the spindle axis. It is advantageous if, for this purpose, the spindle adapter is held in the tool spindle and engages the operating element. This makes it possible to establish the connection between the spindle adapter and the workpiece carrier before or during switching the clamping device to the release state, so that the workpiece carrier with the machined workpiece can be removed from the clamping device and placed, for example, in one of the free storage locations.

[0049] For example, different storage locations can be provided for machined workpieces—i.e., workpieces on which work has been performed in the machine tool—than for tools or workpieces yet to be machined. A magazine unit, for example, can have different magazine sections for these.

[0050] In an embodiment in which the operating element is not actuated via the spindle adapter, the tool spindle can accommodate an operating tool before the operating element is actuated. The operating tool can, for example, comprise a pin, in particular a cylindrical pin. Using the operating tool, the operating element can be actuated or moved particularly easily, for example, if the operating element is an operating lever.

[0051] In one embodiment, the operating element can be an operating lever. The operating lever is preferably pivotably mounted about a rotational axis. It is advantageous if an eccentric body is motion-coupled to the operating lever and, in particular, is connected in a rotationally fixed manner. The eccentric body and the operating lever can form a common component and be monolithically connected to one another. The eccentric body can have a curved surface against which a displaceably mounted slider of the actuating device can rest, analogous to an embodiment of the previously described clamping device according to the invention. Upon a pivoting movement of the operating lever about the rotational axis, the eccentric body executes an eccentric movement, which in turn causes a displacement of the slider.

[0052] In this embodiment, several clamping bodies can be motion-coupled to the slide, allowing them to be moved between a clamping position and a release position. The motion coupling between the clamping bodies and the slide can be realized, for example, via a gear mechanism, in particular via a wedge-shaped arrangement.

[0053] The clamping device can have a base with a top side and a bottom side. On the top side, the base has a support surface, into which preferably several holes each for receiving a retaining bolt open. The retaining bolts are arranged on the workpiece carrier and protrude, for example, parallel to one another from an underside of the workpiece carrier. When the workpiece carrier is placed on the clamping device, the retaining bolts each engage in an associated hole on the base. This creates a positive connection between the base of the clamping device and the workpiece carrier in the circumferential direction around the spindle axis and at right angles to the spindle axis, which connection may be subject to play when the clamping device is released. This enables movement of the spindle adapter at right angles to the spindle axis or in the circumferential direction around the spindle axis in order to establish or release a detachable connection between the spindle adapter and the workpiece carrier.The workpiece carrier is supported by the retaining bolts in the holes in the base.

[0054] The detachable connection between the spindle adapter and the workpiece carrier can, for example, be a snap-in connection.

[0055] The base can have several retaining bolts on its underside, the shape and dimensions of which correspond in particular to the retaining bolts that may be present on the workpiece carrier. The machine clamping device can have holes into which the retaining bolts of the base engage and in which the retaining bolts are held in a clamping manner with a positive and / or non-positive fit.

[0056] Thus, the same clamping principle or clamping system can be used between the clamping device and the machine clamping device on the one hand and between the clamping device and the workpiece carrier on the other.

[0057] It is advantageous if the clamping connection between the machine clamping device and the clamping fixture is always maintained during the machining of one or more workpieces.

[0058] In the inventive design of the clamping device, the operating element is moved, in particular, by a rotational movement of the spindle adapter by means of the tool spindle. In another exemplary embodiment of the clamping device that can be used in the inventive method, the tool spindle can be moved along at least one arbitrary trajectory to actuate the operating element. The at least one trajectory can, for example, run in a plane that is oriented at right angles to the vertical axis of the clamping device or to the rotational axis of the operating element. In one exemplary embodiment, the tool spindle can be moved along a first trajectory to bring the clamping device into the clamped state and / or along a second trajectory to bring the clamping device into the released state. The first trajectory and the second trajectory can differ from one another.

[0059] The first trajectory and / or the second trajectory can have a partially curved and / or partially rectilinear course. In one embodiment, the first trajectory and / or the second trajectory can be a polygonal line consisting of several rectilinear sections. Such movements of the tool spindle along rectilinear sections of a polygonal line can be implemented very easily. In another embodiment, the first trajectory and / or the second trajectory can be continuously curved, for example, a circular arc.

[0060] In one embodiment, the spindle adapter can have a hollow cylindrical outer wall that encloses the workpiece carrier or the workpiece held on the workpiece carrier. However, any other embodiments of the spindle adapter can also be used, particularly within the scope of the method according to the invention. In one embodiment, the spindle adapter can be configured and designed to engage the operating element. In other embodiments of the method according to the invention, in which the operating element is not operated using the spindle adapter, spindle adapters can be used that do not have to be configured to operate the operating element.

[0061] In one embodiment, the spindle adapter has two arms. Each arm has a locking device. When the connection to the workpiece carrier is established, each locking device engages with a counter-locking device of the workpiece carrier. The counter-locking devices of the workpiece carrier are arranged on the outside of the workpiece carrier, for example, in diagonally opposite corner areas of the workpiece carrier. When the locking connection is established, the counter-locking devices or locking devices are preferably diametrically opposite one another with respect to the spindle axis.

[0062] Advantageous embodiments of the invention will become apparent from the dependent claims, the description, and the drawings. Preferred embodiments of the invention are explained in detail below with reference to the accompanying drawings. The drawings show: Fig. 1 an embodiment of a clamping device according to the invention as well as a workpiece carrier and a spindle adapter in a perspective view, Fig. 2 a perspective view of the clamping device from Fig. 1 in a release state, Fig. 3 a perspective view of the clamping device from the Fig. 1 and Fig. 2 in a clamping state, Fig. 4 an actuating device of the clamping device from the Fig. 1 to 3 in the released state based on a cross section along the section plane IV in Fig. 2, Fig. 5 the actuating device of the clamping device from the Fig. 1 to 3 in the clamping state based on a cross section along the section plane V in Fig. 3, Fig. 6-14 each show a block diagram of a machine tool having a tool spindle and a clamping device, wherein different stages of an embodiment of a method according to the invention are shown during the machining of a workpiece, Fig. 15-19 each show a block diagram of a machine tool having a tool spindle and a clamping device, wherein different stages of a further embodiment of a method according to the invention are shown during the machining of a workpiece, Fig. 20 a perspective view of a clamping device which is used in a method according to the invention according to Fig. 15-19 can be used, with a workpiece carrier arranged thereon, Fig. 21 a schematic, block diagram-like principle representation of an actuating device of the clamping device according to Fig. 20, Fig. 22 and Fig. 23 each shows a schematic diagram to illustrate the production of a connection between a retaining bolt of a workpiece carrier and a clamping body of the clamping device, Fig. 24 a schematic diagram of an embodiment of a spindle adapter with locking devices and a workpiece carrier with counter-locking devices for producing a detachable locking connection, Fig. 25 and Fig. 26 each shows a schematic sectional view of a modified embodiment of a locking device for the spindle adapter and a counter-locking device for the workpiece carrier, Fig. 27-29 another embodiment of a clamping device in different representations in a release state and Fig. 30-32 the embodiment of the clamping device from the Fig. 27-29 in a tensioned state.

[0063] The invention relates to a clamping device 10 and a method for handling workpieces 11 which are clamped or held by means of a workpiece carrier 12. The workpiece carrier 12 is in particular a vice or headstock with two clamping jaws 13 which can be moved towards or away from each other. Fig. 1-5 an embodiment of the clamping device 10 according to the invention is shown in different representations.

[0064] In the exemplary embodiment, the clamping device 10 has a base 14. A support surface 15 for the workpiece carrier 12 is provided on an upper side of the base 14. In the exemplary embodiment, the support surface 15 has a circular contour.

[0065] Several holes 16 open into the support surface 15, which are thus open at the top. The holes 16 are arranged at a distance from each other in a predetermined grid. The holes 16 are shown in the Fig. 1 to 5 illustrate four holes 16. The number of holes can also be greater than four.

[0066] Each hole 16 is designed to receive a retaining bolt 17 of the workpiece carrier 12. As shown in Fig. As can be seen in Figure 1, the retaining bolts 17 protrude from an underside of the workpiece carrier 12 opposite the clamping jaws 13. The retaining bolts 17 extend parallel to one another. They are spaced apart in a grid that matches the grid of holes 16. In the exemplary embodiment, the workpiece carrier 12 has four retaining bolts 17. When the workpiece carrier 12 is arranged on the support surface 15, each retaining bolt 17 engages in one of the holes 16.

[0067] The retaining bolts 17 are in the Fig. 1 to 3 and in principle diagrams in the Fig. 22 and Fig. 23. Each retaining bolt 17 has two adjacent sections, in the region of which the cross section of the retaining bolt 17 tapers, for example, conically. In the exemplary embodiment, the retaining bolt has two conical surfaces 18 for this purpose. The two conical surfaces can adjoin one another directly or alternatively be connected to one another via a section, in particular a cylindrical section, as shown in the Fig. 22 and Fig. 23. In the area of ​​the conical surfaces 18, the retaining bolt 17 forms an annular groove 19, which can have a triangular or—as in the exemplary embodiment—a trapezoidal cross-section. All retaining bolts 17 are identically designed.

[0068] An actuating device 23 is arranged on or in the base 14 of the clamping device 10, which in the cross-sectional representations of the clamping device 10 ( Fig. 4 and Fig. 5). By means of the actuating device 23, the clamping device 10 can be switched between a release state L ( Fig. 1, Fig. 2 4 and 27-29) and a tension state S ( Fig. 3, 5 and 30-32). The actuating device 23 has an externally accessible operating element 24 arranged on the base 14 for operation. The operating element 24 is movable between a first position P1 and a second position P2 along a path about a vertical axis H of the clamping device 10. In the Fig. 1-5 and 27-32, the path is a circular path or a circular arc path around the vertical axis H. The path is thus arranged coaxially to the vertical axis H. As shown in the Fig. 1-5 and 27-32, the operating element 24 in these embodiments is formed by an operating ring 25 arranged coaxially to the vertical axis H. The operating ring 25 encloses the support surface 15 and, for example, also the other components of the actuating device 23. The vertical axis H passes through the support surface 15.

[0069] In a modification of the embodiment illustrated here, the operating element 24 can also be formed by a ring segment or another body which is arranged on the base 14 so as to be movable along the path about the vertical axis H.

[0070] The actuating device 23 has a plurality of clamping bodies 31, with each hole 17 assigned a clamping body 31. In the clamping state S, a clamping end 31a of the respective clamping body 31 protrudes into the hole 16 in such a way that a retaining bolt 17 arranged there is subjected to a clamping force. In the release state L, the clamping body 31 is retracted from the assigned hole 16 in such a way that its clamping end 31a allows the unhindered insertion and removal of a retaining bolt 17 into the hole 16.

[0071] The actuating device 23 also has a coupling device 33 which is designed to establish a movement coupling between the operating element 24 and the clamping bodies 31. The coupling device 33 can be designed differently. In the embodiments according to the Fig. 1-5 and 27-32, the coupling device 33 comprises a cam follower arrangement with a cam surface 26 and, for example, also at least one pair of wedge surfaces 29 to effect the movement coupling between the operating element 24 and the clamping bodies 31. Alternatively, other gear arrangements could also be used for the movement coupling.

[0072] In the Fig. 1-5 and 27-32, the coupling device 33 has at least one slider 28 displaceably mounted in the base 14. In the exemplary embodiment, the at least one slider 28 is mounted displaceably at right angles and, in particular, radially to the vertical axis H. Each slider 28 can be brought into direct or indirect contact with the operating element 24 at a contact point 27. The movement coupling between the operating element 24 and the at least one slider 28 is effected via a cam follower arrangement with a cam surface 26, which is arranged either on the operating element 24 ( Fig. 1-5) or alternatively on the at least one slider 28 ( Fig. 27-32). The curved surface 26 arranged on the operating element 24 according to the embodiment of the Fig. 1-5 is arranged inside on the side facing the vertical axis H, wherein the curved surface 26 forms, for example, the inner ring surface of the operating ring 25. In the embodiment according to the Fig. 27-32, each slide 28 has a curved surface 26 which faces away from the vertical axis H and towards the operating element 24 or the operating ring 25.

[0073] The curved surface 26 has an eccentric profile around the vertical axis H, so that it deviates from a circular shape or a circular arc shape around the vertical axis. Depending on whether or where the contact point 27 is located along the respective curved surface 26, the slide 28 assumes different positions relative to the vertical axis H, so that the movement of the operating element 24 can be converted into a linear displacement of the at least one slide 28 in order to switch the clamping device 10 between the release state L and the clamping state S.

[0074] With reference to the Fig. 1-5, the exemplary embodiment is first explained in which the at least one curved surface is arranged on the operating element 24 or the inside of the operating ring 25. The curved surface 26 can extend 360° around the vertical axis H. However, it is sufficient if the curved surface 26 extends in an angular range α around the vertical axis H that is smaller than 360° and can, for example, be approximately 90°. This angular range α is at least as large as the angle by which the operating element 24 can be rotated around the vertical axis H between the first position P1 and the second position P2.

[0075] In the exemplary embodiment, the distance of the curved surface 26 from the vertical axis H changes along its extension. In the exemplary embodiment, the curved surface 26 has a profile that corresponds to a section of a spiral winding.

[0076] At the contact point 27, the slide 28 of the actuating device 23, which is displaceably mounted in the base 14, rests against the curved surface 26 of the operating element 24. At its end opposite the contact point 27, the slide 28 is supported by a pair of wedge surfaces 29 on displaceably mounted wedge bodies 30. The wedge surfaces of the pair of wedge surfaces 29 each extend obliquely to the direction of movement of the slide 28 and obliquely to the direction of movement of the wedge bodies 30. In the exemplary embodiment, the wedge bodies 30 are mounted so as to be movable at right angles to the direction of movement of the slide 28. They can move toward and away from each other. The end of the slider 28 opposite the contact point 27 projects into the space between the two wedge bodies 30 and can move them away from each other when the slider 28 is moved further into this space, and allows the two wedge bodies 30 to approach each other when moving back out of the space.

[0077] Each wedge body 30 has an end opposite the slide 28, which in turn bears against at least one and, for example, two clamping bodies 31 of the actuating device 23. As shown in the Fig. 4 and Fig. As can be seen in Figure 5, each wedge body 30 rests against the associated clamping bodies 31 via a pair of wedge surfaces 29. The wedge surfaces of the pair of wedge surfaces 29 extend obliquely to the direction of movement of the wedge bodies 30 and obliquely to the direction of movement of the clamping bodies 31.

[0078] The two clamping bodies 31, which rest on a common wedge body 30, can be moved toward or away from each other and are mounted accordingly. The direction of movement of the clamping bodies 31 is, for example, parallel to the direction of movement of the slide 28. Each wedge body 30 engages, with its end opposite the slide 28, in a space between the two associated clamping bodies 31 and can move them away from each other when the wedge body 30 is moved further into the space, or allow the two clamping bodies to move toward each other when the wedge body 30 is moved out of this space.

[0079] The two wedge bodies 30 are urged toward each other by a preloading device 32, so that they are pushed against the end of the slide 28. Similarly, the two clamping bodies 31, which are assigned to a common wedge body 30, are urged toward each other by a preloading device 32 and rest against the end of the wedge body 30 arranged between them. A retraction movement of the two clamping bodies 31 or the two wedge bodies 30 toward each other can be effected via the preloading devices 32.

[0080] Each pretensioning device 32 can generate a tensile force between two clamping bodies 31 or between the two wedge bodies 30. For this purpose, the pretensioning device 32 can be connected to the two bodies 30 or 31 between which the tensile force is to be generated. For this purpose, each pretensioning device 32 can comprise a component that generates a tensile force, for example, a tension spring.

[0081] Each clamping body 31 has a clamping element 31a (compare Fig. 22 and Fig. 23), which is associated with a hole 16 in the base. The clamping end 31a is arranged opposite the end at which the clamping body 31 rests against the wedge body 30.

[0082] The actuating device 23 operates with reference to the Fig. 4, Fig. 5, Fig. 22 and Fig. 23 as follows:

[0083] In the first position P1 of the operating element 24, the clamping bodies are in a retracted position in which the clamping elements 31a are arranged substantially or completely outside the holes 16, so that the unhindered insertion and removal of the retaining bolts 17 into and out of the respective hole 16 is possible ( Fig. 4 and Fig. 22). If the control element is moved from the first position P1 to the second position P2 after inserting the retaining bolts 17 into the corresponding holes 16 ( Fig. 5), the slider 28 is thereby moved further between the wedge bodies 30, which in turn are moved away from each other. This leads to the wedge bodies 30 being moved into the space between the two respectively assigned clamping bodies 31 and the clamping bodies 31 of a respective clamping body pair in turn moving away from each other into an extended position in which at least the clamping end 31a projects into the respectively assigned hole 16. At the level of the clamping end 31a, the retaining bolt 17 has the annular groove 19, into which the clamping end 31a engages, which is particularly Fig. 23. In this case, the clamping element 31a can exert a tensile force on the retaining bolt 17, for example, by the clamping element 31a acting on the lower conical surface 18. In this way, the workpiece carrier 12 is clamped or pulled against the support surface 15.

[0084] At the same time, the two retaining bolts 17, which are subjected to a holding force by a common pair of clamping bodies, are pushed away from each other against the wall of the base 14 defining the hole 16. In this way, the workpiece carrier 12 can be clamped very precisely in a desired position by the clamping device 10.

[0085] To release the workpiece carrier 12, the operating element 24 is moved from the second position P2 back to the first position P1. Due to the restoring force of the pretensioning devices 32, both the two clamping bodies 31 of a common clamping body pair and the two wedge bodies 30 are each urged towards one another, thereby constantly moving the slide 28 against the curved surface 26 at the respective contact point 27. If the distance of the curved surface 26 from the vertical axis H increases during the movement from the second position P2 to the first position P1, the slide 28 moves out of the space between the wedge bodies 30, so that the wedge bodies 30 can approach one another. This, in turn, causes the wedge bodies 30 to move out of the space between the clamping body pairs, allowing the clamping bodies 31 of each clamping body pair to approach one another.The clamping elements 31a move partially or completely out of the holes 16 and thus release the retaining bolts 17.

[0086] The operating element 24, for example, the operating ring 25, is motion-coupled to the clamping bodies 31 to move them between the retracted position (release state L of the clamping device 10) and the extended position (clamping state S of the clamping device 10). This motion coupling is achieved via the slide 28, the wedge bodies 30, and the respective wedge surface pairs 29. Instead of a wedge surface arrangement with several wedge surface pairs 29, a different motion coupling can also be achieved via known gear elements, for example, gears, racks, etc.

[0087] The Fig. 27-32, is constructed according to the same principles as the actuating device 23 with regard to the movement coupling. A significant difference between these embodiments is that the actuating device 23 is constructed according to the Fig. 27-32 has two separate slides 28, which are diametrically opposite one another with respect to the vertical axis H and are mounted so as to be movable towards or away from one another. Each slide 28 is coupled in motion to one and, for example, two clamping bodies 31. On its rear side facing the operating element 24 and, for example, the operating ring 25, each slide 28 has a curved surface 26 which extends eccentrically around the vertical axis H. As shown in the Fig. 28 and Fig. As can be seen in Figure 29, in the release state L, contact may exist between the operating element 24 and the slides 28. Preferably, however, a distance is present, and contact is only established when the operating element 24 is moved from its first position P1 toward the second position P2. Thus, in the release state L, no contact point 27 may yet be formed between the operating element 24 and the respective slide 28.

[0088] To ensure that the curved surface 26 has a sufficient length in the direction of extension around the vertical axis H, each slide 28 has an end piece 34 extending in an arc around the vertical axis H, which end piece can be formed, for example, symmetrically to a longitudinal center plane through the slide 28. The longitudinal center plane through the slide 28 also extends, for example, through the vertical axis H.

[0089] For engagement with the cam surfaces 26 of the slides 28, the operating element 24 comprises, for example, rolling elements 35 which are mounted rotatably about an axis parallel to the vertical axis H. Each slide 28 or each cam surface 26 is assigned a rolling element 35. During the movement of the operating element 24, each rolling element 35 can roll on the assigned cam surface 26. By means of such a rolling element bearing between the operating element 24 and the at least one slide 28, the required torque or the required force can be reduced which is necessary to move the operating element 24 between the first position P1 and the second position P2. Such a rolling element bearing can also be used in other embodiments of the clamping device 10, for example in the embodiment according to the Fig. 1-5. There, a rolling element 35 could be arranged at the end associated with the operating element 24.

[0090] In the modified embodiment according to the Fig. 27-32 are omitted compared to the embodiment according to the Fig. 1-5 and 20 and 21, the wedge bodies 30. Rather, the clamping bodies 31 are each in direct contact with the end of the associated slide 28 opposite the operating element 24 by means of a pair of wedge surfaces 29. Two clamping bodies 31 are displaceably mounted on each slide 28 by means of a pair of wedge surfaces 29. The slide 28 can move the two clamping bodies 31 away from each other against the pretensioning force of the pretensioning device 32 in order to bring the clamping device 10 into the clamping state S. During a retraction movement of the slide 28 from the space between the two clamping bodies 31, these are moved towards each other due to the pretensioning force of the pretensioning device 32, whereby the clamping device 10 can be brought into the release state L. The release state L is in the Fig. 27-29 and the clamping state S in the Fig. 30-32. For better presentation, the Fig. 29 and Fig. 32 the hatching lines of the section according to the section line XXIX-XXIX in Fig. 27 or according to section line XXXII-XXXII in Fig. 30 omitted.

[0091] In the embodiments according to the Fig. 1-5 and according to the Fig. 20 and Fig. 21, the wedge bodies 30 can also be optionally dispensed with if a slide 28 is provided for each pair of clamping bodies 31. Conversely, in the embodiment according to the Fig. 27-32, only one slide 28 may be present, in which case additional wedge bodies 30 analogous to the Fig. 1-5 and 20-21 are used.

[0092] The provision of the rolling bearing between the operating element 24 and the at least one slide 28 and / or the omission of the wedge bodies 30 in the coupling device 33 between the slide 28 and the associated clamping bodies 31 contributes to reducing the forces or moments required for actuation.

[0093] In all embodiments, a compensating unit 36 ​​can also be present in the force transmission path between the operating element 24 and the clamping bodies 31. The compensating unit 36 ​​is configured to elastically deform and, for example, to compress when the force in the force transmission path increases or exceeds a force threshold. For this purpose, the compensating unit 36 ​​can comprise one or more elastically deformable bodies, for example, at least one disc spring, at least one coil spring, at least one elastically deformable plastic body (e.g., a hard rubber disc), or any combination thereof.

[0094] The compensation unit 36 ​​is preferably present in each force transmission path from the at least one slide 28 and the associated clamping bodies 31 and can - as in the exemplary embodiments illustrated here - be arranged on each slide 28. For example, the slide 28 can be divided into two slide parts that are movable relative to one another, between which the compensation unit 36 ​​is arranged. If the clamping bodies 31 are in contact with an associated retaining bolt 17 with their clamping ends 31a, the increase in the clamping force between the clamping bodies 31 and the retaining bolts 17 can be limited based on the spring characteristic or the elasticity characteristic of the compensation unit 36. This at least partially compensates for possible tolerances during manufacture of the individual components or during assembly, and the uniformity when clamping the retaining bolts 17 is improved.

[0095] In the Fig. 1 to 3 it can also be seen that the operating element 24 has a coupling device 37. The coupling device 37 is designed to communicate with a counter-coupling device 38 of a spindle adapter 39 (dashed in Fig. 1) to be releasably coupled. When the connection is established, a rotationally fixed coupling is established between the spindle adapter 39 and the operating element 24 in the direction of movement of the operating element 24 about the vertical axis H. In the exemplary embodiment, the connection is established or broken by a relative movement between the spindle adapter 39 and the operating element 24 parallel to the vertical axis H.

[0096] In the exemplary embodiment, the coupling device 37 has at least one projection 40, which extends from the adjacent regions of the operating element 24 of the operating ring 25 parallel to the vertical axis H, in particular beyond the plane in which the support surface 15 is located. Several projections 40, for example, two projections 40, can be arranged at a distance from one another in the circumferential direction around the vertical axis H. In the exemplary embodiment, two projections 40 are diametrically opposite one another with respect to the vertical axis H.

[0097] Each projection 40 is assigned a recess 41 of the counter-coupling device 38. The recess 41 has a contour designed to receive the associated projection 40. Preferably, the width of the recess 41 in the circumferential direction about the vertical axis H is substantially equal to the width of the projection 40 in the circumferential direction about the vertical axis H. This allows a substantially mirror-free, rotationally fixed connection to be achieved when the coupling device 37 and the counter-coupling device 38 establish a connection with one another.

[0098] Alternatively, the recess 41 can be larger in the circumferential direction around the vertical axis H than the projection 40. This allows for a movement clearance between the spindle adapter 39 and the operating element 24. This movement clearance can be used to move the operating element only with a time offset after the start of the relative rotation of the spindle adapter 39 relative to the workpiece carrier 12.

[0099] In the exemplary embodiment, the spindle adapter 39 has a hollow cylindrical peripheral wall 42 in which at least one and, for example, two recesses 41 are present. The recess 41 is present at a lower edge of the peripheral wall 42 and is open downwards. As a result, the peripheral wall 42 can be moved from above towards the operating element 24, so that each projection 40 is received in an associated recess 41. By rotating the spindle adapter 39 about the vertical axis H, the operating element 24 can be moved between the first position P1 and the second position P2. This movement can be carried out by means of the tool spindle 45 of a machine tool 46, as will be described below based on the Fig. 6 to 14. A spindle axis A of the tool spindle 45 can coincide with the vertical axis H.

[0100] The tool spindle 45 of the machine tool 46 is movable in several degrees of freedom, and in particular in at least two linear degrees of freedom, relative to the machine clamping device 47 and the magazine unit 48. The spindle holder 52 can also be rotated about the spindle axis A.

[0101] The machine tool 46 is in the Fig. 6 to 14 is only illustrated in a highly schematic manner. It comprises the tool spindle 45, a machine clamping device 47, and a magazine unit 48 with several storage locations 49 for a tool 50 and / or a workpiece 11. The workpiece 11 is arranged on the workpiece carrier 12, which is connected to the spindle adapter 39 when the assembly comprising the workpiece 11 and the workpiece carrier 12 is deposited at a storage location 49.

[0102] Both the spindle adapter 39 and the tools 50 each have a spindle interface 51 configured to be held in a spindle receptacle 52 of the tool spindle 45. The spindle interface 51 is, for example, a standardized interface, for example a tool taper, such as a Morse taper, steep taper, or hollow shank taper.

[0103] In the Fig. 1 to 3, it can be seen that the base 14 has, on the underside opposite the support surface 15, a plurality of, for example, four retaining bolts 17, analogous to the workpiece carrier 12, which can be equipped identically to the retaining bolts 17 of the workpiece carrier. The machine clamping device 47 of the machine tool 46 can thus also have holes 16 and clamping bodies 31 associated with the holes, as can the actuating device 23 of the clamping device 10. For clamping the clamping device 10 to the machine clamping device 47, the same principle can thus be used as for clamping the workpiece carrier 12 to the clamping device 10. For clamping and releasing the clamping device 10, a slide can also be used, which is motion-coupled to the clamping bodies, for example via wedge bodies and a wedge surface arrangement. For details, reference is made to the above explanation of the actuating device 23 based on the Fig. 4 and Fig. 5.

[0104] The storage locations 49 for tools 50 and a structural unit comprising workpiece carrier 12, workpiece 11, and spindle adapter 39 can be configured as desired. In the exemplary embodiment illustrated here, the storage locations 49 are arranged in the magazine unit 48. The magazine unit 48 can be designed to be completely passive if the tool spindle 45 can reach all storage locations 49. Alternatively, the magazine unit 48 can have movable magazine parts in order to arrange a storage location 49 at a change position, which can be approached by the tool spindle 45 in order to remove the tool 50 or workpiece assembly arranged in the change position or to arrange it on a free storage location 49 of the magazine unit 48 arranged in the change position.

[0105] To form a workpiece assembly from the workpiece 11, the workpiece carrier 12, and the spindle adapter 39, the spindle adapter 39 is detachably connected to the workpiece carrier 12. The connection can be established, for example, based on a bayonet connection or snap-in connection or another type of force-locking and / or positive connection. In particular, the connection is established and released by a relative rotation of the spindle adapter 39 and the workpiece carrier 12 about a longitudinal center axis M of the spindle interface 51 of the spindle adapter 39. The relative rotation for establishing the connection and for releasing the connection is less than 360°, for example, less than 90°, and more preferably less than 45°. The connecting device for establishing this detachable connection can, for example, be designed as shown in Fig. 24 and is explained in connection with a further embodiment of the invention.

[0106] An embodiment of the method according to the invention using the clamping device 10 according to the Fig. 1 to 5 will be explained below with reference to the Fig. 6 to 14 explained in detail:

[0107] It is assumed that in the initial situation, a workpiece 11 to be machined is arranged at a storage location 49 by means of the workpiece carrier 12 and the spindle adapter 39. The clamping device 10 is in the released state L ( Fig. 6).

[0108] The workpiece 11 to be machined is picked up by the tool spindle 45 from the relevant storage location 49 by means of the spindle adapter 39 ( Fig. 7). The tool spindle 45 then moves the workpiece carrier 12 with the workpiece 11 to the clamping device 10 by means of the spindle adapter 39 and places the workpiece carrier 12 parallel to the vertical axis H on the clamping device 10. During this movement, the retaining bolts 17 are each inserted into an associated hole in the clamping device 10 and, in addition, the coupling between the coupling device 37 and the counter-coupling device 38 is established by the projections 40 engaging the recesses 41 ( Fig. 8).

[0109] In this position, the spindle axis A and the vertical axis H of the clamping device 10 coincide sufficiently precisely. Due to the rotational coupling established between the spindle adapter 39 and the operating element 24 by means of the coupling device 37 and the counter-coupling device 38, the tool spindle 45 can cause a rotational movement of the spindle holder 52 about the spindle axis A, so that a rotational movement of the operating element 24 is carried out by means of the spindle adapter 39 from the first position P1 towards the second position P2 and the clamping device 10 assumes the clamping state S ( Fig. 9).

[0110] In the embodiment illustrated here, the spindle adapter 39 is also released from the workpiece carrier 12 during this rotational movement. Subsequently, by a corresponding movement of the tool spindle 45, the spindle adapter 39 can be deposited in a free storage location 49 of the magazine unit 48 ( Fig. 10).

[0111] After the spindle adapter 39 has been removed, the tool spindle 45 can accommodate a tool 50 for performing work on the workpiece 11, for example, machining. In particular, rotating machining tools, such as drills or milling cutters, are used to machine the workpiece 11. Additionally or alternatively, measuring tools can also be used as tools 50 to measure the workpiece 11 before or after machining. Fig. 11 merely illustrates, by way of example, a machining operation of the workpiece 11 using a milling cutter. Fig. 12 shows the machined workpiece 11, which is still held in the machine tool 46 via the workpiece carrier 12 by the clamping device.

[0112] Following the work on the workpiece 11 by means of at least one tool 50, the tool spindle 45 of the machine tool 46 again picks up a spindle adapter 39 from a storage location 49 ( Fig. 12) and moves the spindle adapter 39 toward the clamping device 10 so that the spindle axis A and the vertical axis H essentially coincide. The spindle adapter 39 is detachably connected to the operating element 24 using the coupling device 37 and the counter-coupling device 38. Subsequently, a rotational movement of the spindle adapter 39 about the spindle axis A or the vertical axis H is initiated by means of the tool spindle 45, whereby the operating element 24 is moved from the second position P2 to the first position P1. As a result, the clamping device 10 is switched back from the clamped state S to the released state L. During this rotational movement, a connection is also established between the spindle adapter 39 and the workpiece carrier 12 ( Fig. 13).

[0113] Finally, the machined workpiece can be removed from the clamping device 10 and placed together with the workpiece carrier 12 and the spindle adapter 39 at a storage location 49 ( Fig. 14). The process can then be repeated for another workpiece to be machined.

[0114] Thus, both the workpiece change and the tool change can be carried out solely by moving the tool spindle 45. The clamping device 10 enables automated clamping and release of workpiece carriers 12 on the clamping device 10. The clamping device 10 is mechanically operated by moving the tool spindle 45 and switches between the release state L and the clamping state S. The machine clamping device 47 itself therefore does not need to be hydraulically, pneumatically, or electric-motor-controlled. Using the clamping device 10, automated machining of workpieces 11 with one or more tools 50 can be realized even for machine tools 46 with simple equipment, for example, to produce small series.

[0115] Fig. 20 illustrates in perspective another embodiment of a clamping device 10, in which the operating element 24 is designed as an operating lever 57, which is pivotably mounted on the base 14 about a rotation axis D. The rotation axis D extends perpendicular to the support surface 15 and is offset from the support surface 15. In the exemplary embodiment, the operating lever 57 is mounted on a side region of the base 14 between the support surface 15 and the underside by the retaining bolts 17.

[0116] As in the previous embodiment, the operating lever 57, which here forms the operating element 24, belongs to the actuating device 23. The design of the actuating device 23 for the clamping device 10 from Fig. 20 is schematically shown in Fig. 21. The operating lever 57 can be pivoted about the rotation axis D between the first position P1 and the second position P2. In Fig. 21, the first position P1 is shown in dashed lines and the second position P2 is illustrated by solid lines. The operating lever 57 is coupled in motion to an eccentric body 58 and, as shown, the operating lever 57 and the eccentric body 58 form a common monolithic component. On an outer side facing away from the rotational axis D, the eccentric body 58 has an outer surface which represents the cam surface 26. The slide 28 rests against the cam surface 26 and is mounted displaceably at right angles or radially to the rotational axis D. Otherwise, the actuating device 23 is constructed analogously to the actuating device 23 as described in connection with the Fig. 4 and Fig. 5 of the clamping device 10 according to the invention. In this respect, reference can be made to the above description.

[0117] In the Fig. 20 and Fig. 21, the operating lever 57 is moved by means of a movement of the tool spindle 45 along a path curve K1, K2 between the first position P1 and the second position P2 or pivoted about the rotation axis D. The tool spindle 45 can act directly on the operating lever 57 or use an operating tool 59 with an operating pin 60, as is exemplified in the Fig. 17 and Fig. 18. In this case, the operating pin 60 or the tool spindle 45 is moved along a first curved path K1 to switch the clamping device 10 from the release state L to the clamping state S, which in Fig. 21 is shown in dash-dotted lines. The operating lever 57 is moved from the first position P1 to the second position P2. Conversely, to move the operating lever 57 from the second position P2 to the first position P1 and thus to switch the clamping device 10 from the clamping state S to the release state L, the operating pin 60 or the tool spindle 45 is moved along a second cam track K2, which in Fig. 21 is illustrated by dashed lines.

[0118] The trajectories K1 and K2 are different from each other. They each comprise, for example, a polygonal line with adjoining straight sections. The points where straight sections adjoin one another, requiring a change in direction of movement, are schematically marked by a dot.

[0119] Fig. 24 illustrates another embodiment of a spindle adapter 39. The spindle adapter 39 has two arms 65 arranged on diametrically opposite sides with respect to the longitudinal center axis M of the spindle interface 51. The arms 65 can extend parallel to each other and parallel to the longitudinal center axis M. The arms 65 are at the same distance from the longitudinal center axis M and move on a common path when the spindle adapter 39 rotates about the longitudinal center axis M.

[0120] The arms 65 are connected to the spindle interface 51 of the spindle adapter 39, for example by means of a connecting leg 66. On each arm 65 and, for example, at the free end of each arm 65, the spindle adapter 39 has a locking device 67 which is designed to establish a locking connection with a counter-locking device 68 on the workpiece carrier 12. The locking device 67 and the counter-locking device 68 are shown schematically in Fig. 24. The locking device 67 includes a locking projection 69 projecting obliquely or at right angles from the arm 65. The locking projection 69 extends approximately tangentially or circumferentially around the longitudinal center axis M. A locking body 70 is arranged on the locking projection 69. The locking body 70 can be preloaded in an initial position and moved into the locking projection 69 against the preload force. The locking body 70 can be, for example, a sphere or a spherical segment.

[0121] The counter-locking device 68 has a recess 71 on the workpiece carrier 12 that is open to the outside at the sides. In the exemplary embodiment, the recesses 71 are located diagonally opposite one another in diagonal corner regions of the approximately cuboid-shaped workpiece carrier 12. Within each recess 71, there is a locking recess 72 that is assigned to the locking body 70 and into which the locking body 70 can engage when the locking projection 69 is moved into the recess 71 to establish the locking connection. When the locking projection 69 is moved into the recess 71, the locking body 70 can be moved into the locking projection 69 against the preload force. As soon as the locking body 70 reaches the locking recess 72, the preload force is thereby forced into the locking recess 72. In this state, the locking connection between the locking device 67 and the counter-locking device 68 is established.

[0122] The locking connection can be established and released by a relative rotation of the spindle adapter 39 relative to the workpiece carrier 12, depending on the direction of the relative rotation about the longitudinal center axis M. This relative rotational movement can be carried out by means of the tool spindle 45 if the tool spindle 45 holds the spindle adapter 39 in the spindle holder 52. Once the locking connection is established, the workpiece carrier 12 with the workpiece 11 can be transported by the tool spindle 45, analogously to the embodiment described above.

[0123] In Fig. 24 it can also be seen that the recess 71 can have a stop 73 tangential to the longitudinal center axis M or spindle axis A at least on one side, against which the locking projection 69 rests when the locking connection is established.

[0124] In the Fig. 25 and Fig. 26 are highly schematically illustrated exemplary modifications for the design of the locking device 67 and the counter-locking device 68. In this embodiment, the locking body 70 is arranged immovably on the projection 69, for example at an end of the locking projection 69 opposite the arm 65. Analogous to the embodiment according to Fig. 24, the locking body 70 can protrude upwards.

[0125] On the lower side opposite the locking body 70, the locking projection 69 has a locking arrangement 77. The locking arrangement 77 has a support body 78, which is mounted in a recess 80 on the locking projection 69 by means of a spring arrangement 79. The recess 80 is open at the bottom. The support body 78 can be moved into the recess 80 against the spring force of the spring arrangement 79 and is forced out of the recess 80 by the spring force of the spring arrangement 79. The spring force of the spring arrangement 79 acts in the direction away from the locking body 70.

[0126] When inserting the locking projection 69 into the recess 71 of the workpiece carrier 12, the support body 78 is moved into the recess 80 against the spring force of the spring arrangement 79. As soon as the locking body 70 has reached the locking recess 72, the locking projection 69 can be moved into the locking recess 72. This movement can be carried out by means of the tool spindle 45. Due to the spring force of the spring arrangement 79, the support body 78 is partially or completely pushed out of the recess 80 and takes up the Fig. 26. In this locking position, the spring force of the spring arrangement 79 supports the support body 78 on the workpiece carrier 12 and pushes the locking body 70 into the locking recess 72.

[0127] This design ensures that the locking connection is maintained by the spring force of the spring arrangement 79 as long as no external force acts on the spindle adapter 39 parallel to the longitudinal center axis M. Rotational movements or rotational accelerations of the spindle adapter 39 cannot lead to an accidental release of the locking connection.

[0128] In the circumferential direction around the longitudinal center axis M or tangentially thereto, the locking body 70 preferably rests against the walls of the locking recess 72. To prevent accidental release of the locking connection, it is advantageous if the locking body 70 and the locking recess 72 have mutually associated side surfaces that extend substantially parallel to the longitudinal center axis M.

[0129] The self-locking function described above to prevent accidental release of the locking connection can alternatively be achieved by other configurations, for example if the support body 78 is not arranged on the locking projection 69, but on the recess 71.

[0130] In a further modification, the spring arrangement 79 and / or the support body 78 can also be replaced by an elastically deformable support body, for example by a leaf spring arranged in the recess 80.

[0131] The clamping device 10 according to Fig. 20 and the spindle adapter 39 according to Fig. 24 can be used for an embodiment of the method according to the invention, which is described below with reference to Fig. 15 to 19.

[0132] In the initial situation according to Fig. 15, the clamping device 10 is in the release state L and the operating lever 57 is in the first position P1. As in the first embodiment of the method, the tool spindle 45 can pick up the spindle adapter 39 with the workpiece carrier 12 and the workpiece 11 arranged thereon from a storage location 49 and arrange it on the clamping device 10 ( Fig. 16). Now, the detachable connection between the spindle adapter 39 and the workpiece carrier 12 is released by a relative rotation, which can be carried out by means of the tool spindle 45. For example, the described locking connection is released and the spindle adapter 39 can be placed in a storage location ( Fig. 17).

[0133] After the spindle adapter 39 has been put down, the tool spindle 45 picks up the operating tool 59 and brings the operating pin 60 of the operating tool 59 into contact with the operating lever 57 ( Fig. 17). By a movement along the first trajectory curve K1, the operating lever 57 is pivoted from the first position P1 to the second position P2, thus switching the clamping device 10 to the clamping state S.

[0134] As described in connection with the first embodiment of the method, a tool 50 can then be picked up and the workpiece 11 machined. After the end of the machining, the operating tool 59 can again be picked up and brought into contact with the operating lever 57. By a subsequent movement of the operating tool 59 along the second trajectory K2, the operating lever 57 is moved from the second position P2 back to the first position P1 and the clamping device 10 is thereby brought into the release state L ( Fig. 18).

[0135] The tool spindle 45 can then deposit the operating tool 59 and pick up the spindle adapter 39. The machined workpiece 11 can be picked up by establishing the detachable connection between the spindle adapter 39 and the workpiece carrier 12 and placed in a free storage location 49 ( Fig. 19). This process can be repeated for any number of workpieces.

[0136] The invention relates to a clamping device 10 and a method for handling a workpiece 11 or a structural unit comprising a workpiece 11 and a workpiece carrier 12. Automatic workpiece changing is enabled using a tool spindle 45. For this purpose, a spindle adapter 39 is provided which can be detachably connected to the workpiece carrier 12. The structural unit comprising workpiece 11 and workpiece carrier 12 can thus be transported by means of the spindle adapter 39. The clamping device 10 can be switched between a release state L and a clamped state S by moving an operating element 24. This movement can be carried out by means of the tool spindle 45 in that the tool spindle 45 acts indirectly on the operating element 24 by means of the spindle adapter 39 or an operating tool 59. List of reference symbols: 10 clamping device 11 Workpiece 12 workpiece carriers 13 clamping jaw 14 Base 15 support surface 16 holes 17 retaining bolts 18 Conical surface 19 Ring groove 23 Actuating device 24 Control element 25 Control ring 26 Curve surface 27 Docking point 28 sliders 29 wedge surface pair 30 wedge bodies 31 clamping bodies 31a Exciting 32 Pre-tensioning device 33 Coupling device 34 End piece 35 rolling elements 36 compensation unit 37 Coupling device 38 Negative feedback device 39 spindle adapter 40 lead 41 recess 42 Perimeter wall 45 tool spindle 46 Machine tool 47 Machine clamping device 48 magazine unit 49 storage space 50 tools 51 spindle interface 52 spindle holder 57 Control lever 58 eccentric bodies 59 Operating tools 60 Stylus 65 Arm 66 connecting legs 67 locking device 68 Counter-locking device 69 locking projection 70 locking bodies 71 Deepening 72 locking recess 73 stop 77 Locking arrangement 78 support bodies 79 Spring arrangement 80 recess α angle range A spindle axis D axis of rotation H vertical axis K1 first track curve K2 second track curve L Solution state M Longitudinal center axis of the spindle interface P1 first position P2 second position S clamping state

Claims

[1] Clamping device (10) for clamping a workpiece carrier (12) on a machine tool (46) with a tool spindle (45), the clamping device (10) comprising: - a base (14) with a support surface (15) for arranging a workpiece carrier (12), - an actuating device (23) arranged on the base (14), which has an externally accessible operating element (24) formed by an operating ring (25) which is movable along a path about a vertical axis (H) passing through the support surface (15) between a first position (P1) and a second position (P2) by means of the tool spindle (45) of the machine tool (46), wherein the operating element (24) has a coupling device (37) which is designed to be detachably connected to a counter-coupling device (38) of a spindle adapter (39) which is designed to be held by the tool spindle (45) of the machine tool (46) so that the tool spindle (45) can engage by means of the spindle adapter (39) and a rotational movement of the spindle adapter (39) leads to a movement of the operating element (24) along the path between the first position (P1) and the second position (P2). leads,wherein the clamping device (10) is in a release state releasing the workpiece carrier (12) when the operating element (24) is in the first position (P1), wherein the clamping device (10) is in a clamping state holding the workpiece carrier (12) when the operating element (24) is in the second position (P2). [2] Clamping device according to claim 1, wherein the actuating device (23) has at least one slide (28) which is mounted displaceably on the operating element (24). [3] Clamping device according to claim 2, wherein the operating element (24) has at least one curved surface (26) against which the at least one slider (28) rests, or wherein each slider (28) has a curved surface (26) against which the operating element (24) rests, and wherein each curved surface (26) has a non-coaxial course with respect to the vertical axis (H). [4] Clamping device according to claim 3, wherein at least one rolling body (35) is provided which is rotatably mounted on the operating element (24) or on the at least one slide (28) and which bears against the cam surface (26). [5] Clamping device according to claim 2 to 4, wherein the at least one slider (28) is coupled in movement to a plurality of displaceably mounted clamping bodies (31). [6] Clamping device according to claim 5, wherein the actuating device (23) has a compensating unit (36) which is designed to deform elastically when the force transmitted between the operating element (24) and the clamping bodies (31) exceeds a force threshold value. [7] Clamping device according to claim 5 or 6, wherein the base (14) has a plurality of holes (16) for receiving retaining bolts (19) arranged on the workpiece carrier (12), wherein each hole (16) is assigned a clamping body (31) of the actuating device (23). [8] Clamping device according to one of claims 5 to 7, wherein the at least one slider (28) and the clamping bodies (31) are coupled in movement via a wedge surface arrangement. [9] Clamping device according to one of the preceding claims, wherein a spindle axis (A) of the tool spindle (45) coincides with the vertical axis (H) of the clamping device (10) when the connection between the coupling device (37) and the counter-coupling device (38) is established. [10] Method for handling a workpiece (11) in a machine tool (46), wherein the machine tool (46) has storage spaces (49) for workpieces (11) and tools (50) and a tool spindle (45) movable in several degrees of freedom, the method comprising the following steps: - Attaching a clamping device (10) for clamping a workpiece carrier (12) to the machine tool (46), - Providing at least one tool (50) and at least one workpiece assembly comprising a workpiece carrier (12) with a workpiece (11) and a spindle adapter (39) connected to the workpiece carrier (12), - Picking up the workpiece carrier (12) by means of the spindle adapter (39) through the tool spindle (45), transporting the workpiece carrier (12) to the clamping device (10) and placing the workpiece carrier (12) on the clamping device (10), - releasably connecting a coupling device (37) of an externally accessible operating element (24) to a counter-coupling device (38) of the spindle adapter (39), wherein the operating element (24) is formed by an operating ring (25) arranged coaxially to a vertical axis (H), - rotating the spindle adapter (39) by means of the tool spindle (45), whereby a movement of the operating element (24) along a path around the vertical axis (H) between a first position (P1) and a second position (P2) is carried out in order to bring the clamping device (10) into a clamping state (S), - Loosen the connection between the spindle adapter (39) and the tool spindle (45), - Picking up the tool (50) and carrying out work on the workpiece (11) by means of the tool (50) arranged in the tool spindle (45). [11] Method according to claim 10, wherein the connection between the spindle adapter (39) and the workpiece carrier (12) is released before or during the actuation of an operating element (24) for switching the clamping device (10) into the clamping state (S). [12] Method according to claim 10 or 11, wherein the tool spindle (45) deposits the tool (50) after performing the work on the workpiece (11). [13] Method according to one of claims 10 to 12, wherein the tool spindle (45) receives the spindle adapter (39) and actuates the operating element (24) of the clamping device (10) by a movement of the tool spindle (45) in order to bring the clamping device (10) into a release state (L). [14] Method according to claim 13, wherein the connection between the spindle adapter (39) and the workpiece carrier (12) is established after or during the actuation of an operating element (24) for switching the clamping device (10) into the release state (L). [15] Method according to one of claims 10 to 14, wherein the clamping device (10) is designed according to one of claims 1 to 12.

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