Hot forming apparatus and method, in particular for forging a workpiece

Abstract

The invention relates to a device and a method for hot forming, in particular forging, of a workpiece (8). The process is provided that a) the workpiece (8) is formed in a forming operation during a working stroke (H) in a working space (A) of two converging tools (4, 6) of a forming machine (1), and b) the workpiece (8) is held in a forming position (U) located in the working space (A) by means of a handling device (7) during the forming operation, wherein c) the handling device (7) pre-positions the workpiece (8) in the working space (A) in a predetermined pre-position (V) spaced apart from the tools (4, 6) before the forming operation, and wherein d1) the workpiece (8) pre-positioned in the pre-position (V) is moved from the pre-position (V) to the forming position (U) by a tool (4) which is moved along a tool movement axis (W) to the forming position (U) during the working stroke (H).and / or d2) the workpiece (8) pre-positioned in the pre-position (V) is moved by the handling device (7) to the forming position (U) in a movement synchronous with a tool (4) moving in the working stroke (H) along a tool movement axis (W) to the forming position (U).

Description

[0001] The invention relates to a device and a method for hot forming, in particular forging, a workpiece.

[0002] Forming machines, particularly impact forming machines, are known for the industrial forging of workpieces. Impact forming machines comprise a work area or work space in which two tools can be moved relative to each other. Generally, the tool movement occurs through a linear movement of at least one tool along a tool movement axis.

[0003] Before a forming process, the workpiece is placed on a tool according to a forming position in the tool's working area. The workpiece is then formed during the tool's working stroke by the impact force, impact energy, or forming energy when the tool hits the workpiece.

[0004] The required forming force and forming temperature depend on the respective material, as well as on the requirements for dimensional accuracy and surface quality.

[0005] Malleable materials are essentially all malleable metals and metal alloys, including both ferrous materials such as steels and non-ferrous metals such as magnesium, aluminum, titanium, copper, nickel, and their alloys. The temperatures encountered during forging can range from 550°C to 750°C (so-called semi-hot forging) and even higher, e.g., above 900°C (so-called hot forging).

[0006] The forming temperature is usually set in a temperature range in which the formability or flowability of the material required for forming is present, in which recovery and recrystallization processes take place in the material and in which undesirable phase transformations can also be avoided.

[0007] From DE 10 2004 015 675 B4, EP 1 944 103 A2, which forms the basis for the preamble of claims 1 and 10, US 4,031,736 A, and US 3,427,853 A, it is known to move or hold workpieces using a gripper during forming. In particular, from DE 10 2004 015 675 B4, it is known to use handling devices, in particular industrial robots, for the automated handling of workpieces during forging. Such handling devices can, as described in DE 10 2004 015 675 B4, have a gripper device or a gripper system and a transport device or a manipulator coupled to the gripper device for spatially moving the gripper device. The gripper device is designed to grip and transfer the workpieces, to insert them into the forming tool and accordingly to remove or discharge the workpieces after the forming process.A corresponding handling device and an associated forming machine are also known from WO 2005 / 023455 A1.

[0008] Due to the forging and forming forces that occur during forging and the comparatively high dynamics of the forming process itself, it is necessary under certain circumstances to hold the workpiece during the forming process.

[0009] In this context, DE 10 2004 015 675 B4 discloses a handling device for a forging machine with which a workpiece can be held during a forming process. The gripper device for gripping the workpiece and the transport device or manipulator for the gripper device or the workpiece are rigidly coupled in an operating position. During forming, the rigid coupling is released, whereby after the rigid coupling is released, the gripper device and the transport device or the manipulator are only elastically decoupled and connected via a damper element. In the rigidly coupled state, the damper element acts as a fixed bearing. The damper element dampens the shocks and vibrations occurring during forming, so that they cannot propagate from the gripper system to the manipulator.

[0010] It is an object of the invention to provide a novel method and a novel device for hot forming, in particular for forging, a workpiece. Furthermore, a method and a device for hot forming are to be provided with which improved forming results can be achieved.

[0011] This object is achieved by the features of the independent claims. Further embodiments of the invention emerge from the features of the dependent claims and from the following description.

[0012] According to a finding underlying the invention, in the above-described known forging machines for hot forming, in particular for bulk forming, the workpiece held in the forming position is in contact with the forming tool for a comparatively long time, which can cause the workpiece to cool locally or even completely cool down, which can have an adverse effect on the forming result and workpiece quality. An improvement in the forming result by reducing the cooling before the actual forming process can be achieved in particular by the device-related and method-related configurations according to the invention described herein.

[0013] According to one embodiment, a method for hot forming a workpiece is provided. Hot forming preferably involves bulk forming, more preferably the forging of workpieces. The device used to carry out the method can comprise, for example, a forming machine, in particular a percussive forming machine, a hammer, for example a hydraulic one, a screw press, and the like. Hot forming is also understood to include semi-hot forming, particularly in the temperature ranges mentioned above.

[0014] The forming machine can have a stationary tool and a moving tool, e.g., hydraulically or mechanically, which is moved from a starting position along a tool movement axis toward the stationary tool in a working stroke to form the workpiece. The workpiece is formed in the area of, or upon reaching, the forming point. After forming, the tool is moved back to its starting position in a return stroke.

[0015] However, the underlying invention is not limited to forming machines with one fixed and one moving or movable tool, but can also be applied in the same way to forming machines with two tools, e.g., moved to the forming point.

[0016] The method provides for the workpiece to be formed in a forming process during a working stroke in a working space of two tools of a forming machine that are moving toward each other. During the forming process, the workpiece is held in a forming position located within the working space by means of a handling device.

[0017] The handling device can further be provided to move the workpiece towards and away from the work area and / or to reposition or relocate the workpiece in the work area, for example when the workpiece is formed in several successive forming processes.

[0018] The method provides that the handling device, which can in particular be operated automatically, pre-positions the workpiece in the work area in a predetermined pre-position (or intermediate position or waiting position) at a distance from the tools before the forming process, i.e. before forming by the tools. The pre-position can be understood as a waiting position located within the working stroke, in which waiting position the workpiece is positioned by the handling device. In the pre-position or waiting position the workpiece is arranged at a distance from the tools, in particular in such a way that heat transfer, in particular heat conduction through mechanical contact, from the workpiece to the tool(s) is reduced, preferably avoided or negligible.In particular, the pre-position can be selected such that thermal contact between the workpiece and the tool(s) is avoided, so that heat transfer from the workpiece to the tools is essentially avoided.

[0019] With regard to the tool(s), the pre-positioning of the workpiece in the pre-position is preferably a floating position in the work area. The workpiece can, for example, be held solely by the handling device.

[0020] In advantageous embodiments, the method can provide for the workpiece to be positioned or held in a suspended position in the work area for a certain period of time. This period can, for example, be within the duration of the working stroke. The workpiece can be positioned in a suspended position in the pre-position while the tools move relative to one another. Particularly advantageously, the workpiece is positioned in a suspended position such that the contact time of the workpiece with the tools is minimized.

[0021] Preferably, it can be provided that the workpiece pre-positioned in the pre-position is positioned in a floating manner in the working space for a predetermined minimum time interval, which depends on the respective forming process, within a working stroke, so that a contact time of the workpiece with the tools is minimized.

[0022] If one of the tools is stationary and the other is moved during the working stroke, the pre-position can be selected such that the side of the workpiece facing the stationary tool is at a predetermined distance from the stationary tool. The distance can be selected, for example taking into account the temperature of the workpiece, such that heat transfer from the workpiece to the tool is reduced, preferably substantially avoided. Generally speaking, the pre-position can be defined or selected such that the side of the workpiece facing a respective tool, in the pre-position, has a predetermined minimum distance from the tool at least for a given time interval or time window during the working stroke.The time window is preferably selected, and the handling unit is preferably operated, such that the time interval or time window during which the workpiece has no contact with the tool(s) is maximized. The minimum distance can be selected depending on the workpiece, the shape of the workpiece and / or the tools, and / or the workpiece temperature.

[0023] In the process, the pre-position can be maintained, for example, over a specified minimum time interval, whereby the minimum time interval can depend on the respective forming machine, the respective forming process, the movement of the tool(s), the type of workpiece material, the workpiece shape, the tool shape, the tool engraving, the workpiece temperature, etc.

[0024] According to one method of the method, it is provided that: d1) the workpiece pre-positioned in the pre-position is moved from the pre-position to the forming position by a tool moved in the working stroke along a tool movement axis to the forming position.

[0025] The tool moved to the forming position during the working stroke can act as a driver, hitting the workpiece in the pre-position area and taking it to the forming position. When the workpiece, guided by the tool acting as a driver, hits the other tool, the workpiece also comes into contact with this other tool and is formed during the working stroke through the action of both tools. With this procedure, the workpiece can be positioned in a floating position for the period from positioning in the pre-position until it is taken along by the tool. During this time, the workpiece is not in contact with either tool, and heat transfer through thermal contact can be avoided.

[0026] The distance between the tool and the workpiece in the pre-position can be selected in such a way, and is advantageously also selected in such a way that up to and / or around the time the workpiece is taken along, there is essentially no, i.e. no significant, heat flow from the warm workpiece to or into the tool(s). Consequently, in known forming machines, cooling of the workpiece prior to the forming process as a result of contact between the workpiece and the tool(s) can be avoided, or at least significantly reduced. For example, such a reduction can be achieved in comparison to forming processes in which the workpieces are placed directly onto a tool by the handling device and are in thermal contact with the tool.

[0027] The workpiece temperature as such is a parameter that influences the quality of the finished workpiece with regard to formability, flowability, recrystallization, etc. With the proposed procedure, it is possible, as described, to reduce or essentially avoid (local) cooling of the workpiece due to heat flow to and into the tool through thermal contact with the workpiece before the actual forming process. In particular, this can be achieved by minimizing the contact time between the workpiece and the tool before the forming process. Such an approach can have a positive effect on the final workpiece quality. Furthermore, due to an overall reduction in contact time with the tool(s), less heat is introduced into the tools, which can also have a positive effect on the durability and / or cooling requirements for the tools.In particular, the contact time can be reduced essentially to the forming time, which depends on the specific forming process and can be as short as a few milliseconds. In comparison, this contact time is significantly shorter than with forming machines, where the workpiece is positioned directly on the tool and held there until the moving tool impacts.

[0028] In a further procedure of the proposed method, which can be carried out alone or in combination with the procedure described above, it is provided that: d2) the workpiece pre-positioned in the pre-position is moved to the forming position by the handling device in a movement synchronous with a tool moved in the working stroke along a tool movement axis (W) to the forming position.

[0029] In this procedure, the workpiece is held in the pre-position, for example in a floating position, at a distance from the tools. The distance is preferably selected such that heat transfer from the workpiece to the tool(s) through thermal contact is essentially avoided. In contrast to the procedure according to d1) described above, the workpiece is moved into the forming position by the handling device itself, and not by the tool as a driver. For this purpose, the handling device can carry out a transfer or movement process in which the workpiece is (automatically) transferred from the pre-position to the forming position. If one of the tools is stationary, the handling device can be operated such that the workpiece is positioned in the forming position on or almost on the stationary tool.The transfer or movement process can be triggered depending on the position of the moving tool, for example, depending on the distance between the moving tool and the workpiece positioned in the pre-position. A corresponding trigger can be selected or specified so that the handling device has sufficient time to properly position the workpiece before the moving tool impacts the stationary tool, for example.

[0030] Analogous to the procedure according to d1), in which a tool acts as a driver, the procedure according to d2), in which the handling device initially positions the workpiece in a suspended position and then transfers it to the forming position, can also reduce, or in particular minimize, the contact time of the workpiece with the tools within a working stroke, e.g., in the period before the actual forming process. This allows the workpiece to cool down before forming and reduce heat input into the tools, etc., particularly due to the lack of direct thermal contact between the workpiece and the tool(s).

[0031] Both procedures according to d1) and d2) demonstrate the commonality that the contact time between the workpiece and the tool(s) can be minimized in the period prior to the actual forming process. Accordingly, cooling due to thermal contact can be reduced to a minimum.

[0032] In one embodiment, the pre-position can be selected such that the workpiece in the pre-position, or at least upon reaching the pre-position, has a predetermined distance, for example a predetermined minimum distance, from the forming position and / or from a stationary tool, for example a support position on the stationary tool, in the direction of the tool movement axis along which the moving tool moves. The pre-position can be selected such that the predetermined distance and / or the pre-position as such are maintained or assumed for a certain duration, e.g. a predetermined minimum duration. The minimum duration is preferably greater, in particular significantly greater, than the switching times, stopping and / or braking times of the handling devices used in each case.

[0033] For example, the pre-position can be selected in such a way that the duration in which the workpiece can be or is held in a suspended state, in particular suspended at rest, in the pre-position is maximum for the duration of the working stroke, while at the same time maintaining a preferred distance at which cooling or cooling of the workpiece, which is crucial for the forming process, is avoided by heat input or heat discharge into the tool.

[0034] The proposed procedures are therefore suitable for reducing the contact time of the workpiece with the tools before the forming process in order to counteract, for example, local cooling of the workpiece.

[0035] According to one embodiment, the synchronous movement is carried out and / or triggered according to the procedure according to d2) as soon as the tool moved towards the forming position reaches a reference position during the working stroke. The reference position can be selected depending on the respective forming process. For example, the reference position can be selected such that the handling device has sufficient time from the trigger until the impact of the moved tool to properly position the workpiece in the forming position, e.g. on a tool, and to be able to carry out further operations if necessary. Such further operations can be carried out, for example, in order to transfer the handling device into a configuration which makes it possible to elastically, in particular elastically damped, separate at least parts or partial areas of the handling device from the workpiece orfrom the vibrations or impacts propagating across the workpiece during forming. Such elastic decoupling may be necessary if parts or sub-areas of the handling device are sensitive to shocks and impacts, etc., such as those that occur during forming, because the proposed method requires the workpiece to be held or fixed by the handling device during forming.

[0036] The synchronous movement can, as already indicated, for example, be carried out or arranged in such a way that the workpiece reaches the forming position, for example a forming position on a stationary tool, and, if necessary, the handling unit is elastically decoupled before the moving tool acts on the workpiece for forming.

[0037] The synchronous movement can be understood in particular as a movement that occurs concurrently with or accompanied by the movement of the moving tool, whereby the workpiece guided or moved by the handling device leads the moving tool toward the forming position, and the workpiece reaches the forming position before the moving tool. The lead of the workpiece can be adjusted and is preferably adjusted so that the handling device has sufficient time in the area of ​​the forming position to position and / or align the workpiece and, after positioning and / or alignment, if necessary, sufficient time to adjust the elastic decoupling.

[0038] According to one embodiment, the orientation of the workpiece in the pre-position or waiting position can essentially correspond to the orientation intended for the forming position, except for a displacement or movement parallel to the tool movement axis, i.e., parallel to the movement of the moving tool. This can be advantageous, for example, in the process according to d1) if the workpiece in the pre-position is driven by the tool, because the moving tool acting as a driver essentially leads to a parallel displacement of the workpiece toward the forming position.

[0039] According to an embodiment according to claim 1 and claim 10, the handling device comprises a gripper system and a manipulator designed for spatial movement of the gripper system. The manipulator can be a robot arm or the like. The gripper system can, for example, comprise at least one gripper unit with one, two, or more gripping elements or gripper fingers for gripping and holding the workpiece and, optionally, one or more gripper drives. The gripper unit can, for example, be attached to the manipulator via an arm or leg.

[0040] A gripper is understood to be any element that enables the gripping and holding of a workpiece, for example, in the manner of a clamp, clamp, or gripper, etc. In the broadest sense, the manipulator forms a transport or movement unit for the gripper system, with which the gripper system can be spatially moved and, if necessary, aligned, for example, according to several translational degrees of freedom and one or more rotational degrees of freedom.

[0041] The gripper system is connected to the manipulator via an intermediate damper element, in particular a mechanically damping, elastic element (or elastomechanically damping element), more precisely via one, two, or more such damper elements. The (at least one) damper element at least partially decouples and / or can be decoupled from the manipulator in an elastically damping manner. The damper element can, for example, be an elastomechanical damper element or absorber element for vibration, shock, bounce, and / or impact energy damping or absorption, comprising, for example, a damper / absorber material made of plastic. The damper element effects an elastomechanically damping decoupling, also referred to herein as "elastic decoupling."

[0042] In general, the damping element can be designed and mounted to elasto-mechanically decouple the gripper system from the manipulator, so that vibrations, shocks, and the like propagating toward the manipulator via the gripper system during the forming process can be at least partially dampened and / or at least partially absorbed. Advantageously, the damping element is designed, configured, and mounted in such a way that the manipulator, which is generally less mechanically resilient, can nevertheless withstand the loads that occur during the operation of the combination of forming machine and handling device during the forming process and that act on the damping element via the gripper system.

[0043] The gripper system can be coupled to or with the manipulator in such a way that the manipulator is elastically decoupled from the gripper system via the damper element, at least for the duration of the forming process or forming step (e.g., process sequence according to d1) or at least from the time of entrainment by the tool until the end of the forming process (e.g., process sequence according to d2). The damper element can comprise one or more materials that make the damper element flexible and / or yielding and / or damping, restoring, or elastomechanically absorbing.

[0044] An elastomechanically decoupleable gripper system is known, for example, from DE 10 2004 105 675 B4. Such a gripper system can be used, for example, in a process sequence according to d2).

[0045] According to one embodiment, the handling device, for example in the process sequence according to d1), is operated or can be operated in such a way that the gripper system, when the workpiece is pre-positioned, is or will be elastically decoupled from the manipulator via the damping element, i.e. elasto-mechanically decoupled. In one embodiment, the handling device can be operated or can be operated in such a way that the gripper system is or will be elastically decoupled from the manipulator at least immediately before the co-movement by the tool in the process sequence or in step d1). The damping element is set up, arranged, mounted and / or designed in such a way that, in the elastically decoupled state, the co-movement of the workpiece held by the gripper system as well as the forces arising during the forming process, etc., can be at least largely absorbed or dampened. In order for the co-movement of the workpiece by the tool, e.g.In order to ensure that the impact of the moving tool and the associated vibrations or impacts, etc., can be absorbed or dampened, it is advantageous if the distance between the pre-position and the forming position is selected in such a way that the driving path or the driving movement can be compensated or bridged by the damping element.

[0046] The damper element can, for example, comprise a block, a strip or cylinder made of elastic, flexible and / or yielding, damping and / or restoring material, containing, for example, one or more plastics, such as elastomers. In addition to the elastic etc. material, further materials or elements can be incorporated, for example to achieve suitable elastomechanical properties. An elastic element that can be used within the scope of the invention is described, for example, in DE 10 2004 015 675 B4. The damper element can, for example, comprise a block made of elastic etc. material arranged between two metal disks or metal plates, wherein the elastic etc. material can, for example, absorb pressure and / or shear forces. In particular, the damper element can comprise a rubber buffer or be designed as such.

[0047] According to an embodiment according to claim 1 and claim 10, the handling device is operated or can be operated such that the gripper system is or is supported on or against the manipulator, at least in the pre-position of the workpiece, by at least one pre-tensioning element with a variably adjustable or a fixed pre-tensioning force. The pre-tensioning element can be, for example, a spring element (e.g. with a fixed pre-tensioning force), a pneumatic element and / or a hydraulic element (each, for example, with a variably adjustable pre-tensioning force). The pre-tensioning element can be configured such that the pre-tensioning force generated or that can be generated, e.g. acting on the gripper system, is sufficient to keep the gripper system with the workpiece stable in position relative to the manipulator, so that the manipulator can stably position the gripper system with the workpiece and handle it safely.For example, the preload force can be selected such that it can absorb the (weight) forces and moments caused by the gripper system and workpiece, so that the gripper system with the gripped workpiece can be moved and positioned stably and reliably by the manipulator despite being fastened via the damper element. For the process sequence according to d1), the preload element, and with it the preload force, is configured, for example, such that the preload force is overpowered by the driving force generated by the driving tool, in particular such that the elastically decoupled manipulator remains essentially stationary during driving. This means that the preload force generated by the preload element is smaller than the driving force of the tool. As a result, the preload element can be deformed when the workpiece is driven by the tool in the process sequence according to d1).For example, and depending on how it is attached, it can be compressed or shrunk, decompressed or stretched. This deformation in turn allows the gripper system to move relative to the manipulator, in particular to move along with the tool, while the manipulator remains or can remain essentially stationary. Any relative position and length changes, caused e.g. by tilting or translating the gripper system relative to the manipulator, can be compensated for by the damping element. This means that the workpiece can be carried along without significant movement or with the manipulator remaining essentially stationary, without the manipulator being subjected to unreasonably high mechanical loads during the carrying process.

[0048] The preload element can, for example, be attached to an arm (or leg, boom, or extension) of the manipulator on the one hand and to an arm (or leg, boom, or extension) of the gripper system on the other, for example on mutually facing sides of the respective arms, and can preload these against each other. The arm of the gripper system can be fixedly mounted or clamped to the arm of the manipulator via the damping element, whereby the bearing or clamping point of the preload element on the arm of the manipulator can be arranged or attached at a distance from the free end of the manipulator arm. End-mounting at the free end of the arm is also possible.

[0049] Accordingly, the bearing or clamping point on the arm of the gripper system can be arranged or mounted at a distance from the end attached to the manipulator.

[0050] The preload element can be attached and designed in such a way that the preload force holds or positions the arms of the manipulator and the gripper system, which are coupled to one another via the damping element, in the non-overcompressed state at a predetermined (with a fixed preload force) or variable or variably adjustable (with a variable preload force) angle to one another.

[0051] According to one embodiment, as already mentioned, the preload force generated or provided by the preload element is at least partially overridden by the moving tool when the pre-positioned workpiece is moved along according to the method sequence according to d1). The overridden action can, for example, occur in such a way that the arms of the manipulator, on the one hand, and the gripper system, on the other hand, which are coupled to one another via the damping element and form two legs extending from the damping element, move towards one another while reducing the leg angle between them. During overridden action, the arm or leg of the manipulator remains essentially stationary or oriented in the same position and applies the counterforce required for overriding to the preload element.The damper element elastically decouples the manipulator from the gripper system, so that the manipulator only has to apply the counterforce and is still essentially elastically decoupled from shocks or vibrations during the forming process.

[0052] The process sequence according to d1) can essentially be implemented purely mechanically and does not require any active movements of the manipulator and gripper system after positioning the workpiece in the pre-position. Thus, in this variant, positioning in the pre-position is sufficient, while at the same time, the contact time of the workpiece with the tools can be minimized or reduced, and the manipulator is essentially elastically decoupled from the workpiece and gripper system during the forming process.

[0053] According to one embodiment, in particular according to the method sequence according to d2), the workpiece is placed on a tool by the synchronous movement of the manipulator and thus of the gripper system with the workpiece to the forming position, which is or is reached, for example, at the end of the synchronous movement. The position of the workpiece on the tool corresponds to the forming position of the workpiece defined by the tool. With the workpiece in place, i.e. when or as soon as the workpiece rests on the tool, the handling device can be operated or adjusted in such a way that the manipulator is or is at least partially elastically decoupled from the gripper system. This means that the handling device can be operated in such a way that the elastic decoupling is present at least during the forming process and the associated and caused forces. Before the elastic decoupling and after the forming process, e.g.After a waiting period or cooldown period following the forming process for possible forming effects on the manipulator, the manipulator and the gripper system can be or become mechanically rigidly coupled by a rigid coupling. Thus, it can be provided that the elastic decoupling is only present and at least during the forming process. Outside of this time frame, the manipulator and the gripper system can be or become mechanically rigidly coupled. A rigid coupling outside of the forming process is advantageous with regard to precise movement control of the workpiece.

[0054] According to one embodiment, the handling device can be operated such that the gripper system and the manipulator are or become mechanically rigidly coupled by a rigid coupling before positioning the workpiece in the pre-position or before positioning in the forming position and / or after the forming process has been completed. Such operation is applicable, for example, to the process sequence according to d2), wherein the rigid coupling can be released, for example, after positioning in the forming position and before the forming process, and can be restored after the forming process.

[0055] Depending on the design of the pre-tensioning element, rigid coupling may be omitted in the process sequence according to d1), for example if the pre-tensioning force and the pre-tensioning element are designed to keep the gripper system sufficiently stable relative to the manipulator even when the workpiece is picked up.

[0056] According to one embodiment, the rigid coupling between the gripper system and the manipulator can be adjusted or established and / or released by essentially complementary movements of the manipulator relative to the gripper system and / or by essentially complementary movements of a coupling element. The gripper system can be or remain essentially stationary, e.g., immobile, during the adjustment and / or release of the rigid coupling. The movement of the manipulator relative to the gripper system can comprise rotating, tilting, pivoting, and / or angling. The coupling element can, for example, comprise an adjustable coupling rod and / or a (e.g., adjustable) locking element. Such coupling elements can be connected to an adjusting member, which can transfer the coupling element between a rigidly coupled and an uncoupled position.Accordingly, the complementary movements can be arranged such that a first movement sequence positions the manipulator relative to the gripper system in such a way that it is elastically decoupled from the gripper system, while a second, complementary movement sequence positions the manipulator relative to the gripper system in such a way that it is rigidly coupled to the gripper system.

[0057] In the process sequence according to d2), it is possible, for example, that the workpiece is placed on the tool and that the manipulator, with the workpiece placed on it and the tool as an abutment, is angled or tilted relative to the gripper system, thus eliminating a rigid coupling between the manipulator and the gripper system.

[0058] A handling device with a manipulator and gripper system, in which the manipulator can be optionally elastically decoupled and rigidly coupled to the gripper system, is known, for example, from DE 10 2004 015 675 B4, wherein the handling device known therefrom can be used, for example, for the process sequence according to d2) described herein.

[0059] According to one embodiment of the device, a device is provided for hot forming, in particular impact forming, in particular forging, of a workpiece. The device is configured, for example, such that it can be used or operated in or with a method described herein.

[0060] Within the scope of the invention, a device is further provided which comprises a forming machine, a handling device and at least one control unit, which are set up and designed to carry out a method with all the features according to one of the methods and method embodiments described herein according to the invention. For example, the control unit can comprise a computing unit, e.g. a control or regulating unit, or a computer unit, for controlling or regulating the handling device and / or the forming machine, which comprises a memory with computer-readable electronic instructions which, when executed by the computing unit, effect a method in the device as described herein according to the invention.

[0061] A device according to the invention can comprise at least one forming machine, for example at least one percussive forming machine. The forming machine can comprise at least two tools which can be moved towards one another relative to one another and are designed to carry out a forming process during a working stroke in a working space of the tools. The working space of the tools is defined by the movement space of the tools. The forming machine can, for example, have a stationary and a movable tool, wherein the movable tool is moved towards the stationary tool in a working stroke to carry out a forming process, for example in a vertical movement, and executes a return stroke after the forming. Such operation corresponds to a generally known forming machine, for example for hot forming and / or bulk forming.

[0062] The device comprises a, i.e., at least one, handling device for handling, i.e., for the automated handling, of workpieces. The handling device, in turn, comprises a, i.e., at least one, manipulator for the spatial movement of a, i.e., at least one, gripper system coupled to the manipulator. The gripper system is configured to grip and / or hold the workpiece even during the forming process.

[0063] In the context of this invention, a handling device is to be understood in particular as an automated system for handling workpieces, such as an industrial robot, with which a workpiece can be brought into the working space of the forming machine and positioned, and with which the workpiece can be held during the forming process.

[0064] The device comprises at least one control unit for controlling and / or regulating the movements of at least the handling device, e.g. the manipulator and the gripper system, wherein the control unit is designed to control or regulate the handling device in such a way that the workpiece is pre-positioned in the working space in a predetermined pre-position (or waiting position) spaced from the tools prior to the forming process.

[0065] In one embodiment, the control unit is further configured to control or regulate the handling device, in particular the manipulator and the gripper system, and optionally the movement of the tool(s) such that the workpiece pre-positioned in the pre-position is moved from the pre-position (or waiting position) to the forming position by a tool moved in the working stroke to the forming point, wherein the workpiece is held by the handling device during the movement and the forming process. This mode of operation corresponds to the method sequence d1) described above, and reference is additionally made to the corresponding explanations above, which apply accordingly to the device.

[0066] The control unit is alternatively or additionally configured to control or regulate the handling device, in particular the manipulator and the gripper system, and optionally the movements of the tool(s), such that the handling device transfers the workpiece from the pre-position to the forming position in a movement synchronous with a tool moved in the working stroke to the forming position as soon as the tool moved towards the forming position reaches a reference position, in particular a predetermined or predeterminable one, in the working stroke, wherein the workpiece is held by the handling device during the forming process. The synchronous movement can comprise a movement concurrent with the moving tool, wherein the movement is advantageously carried out such that the workpiece leads the tool.This mode of operation corresponds to the process sequence d2) described above, and reference is also made to the corresponding explanations above, which apply accordingly to the device.

[0067] According to one embodiment of the device according to claim 1, the handling device has one, i.e. at least one, manipulator and one, i.e. at least one, gripper system connected to the manipulator. The gripper system is connected to the manipulator via an intermediate damping element. In the non-rigidly coupled configuration already described above, the damping element enables elastic decoupling of the gripper system from the manipulator. In particular, the damping element has elastomechanical properties that dampen or absorb mechanical energy propagating in and via the gripper system during the forming process in the form of oscillations, shocks, vibrations, etc., so that these effects are not or substantially not propagated into the manipulator.The damping element is thus designed to at least partially, preferably largely, dampen or absorb the effects of the forming process transmitted and propagating via the gripper system.

[0068] The control unit can be configured to control or regulate the manipulator and / or a coupling element such that the gripper system and the manipulator are elastically decoupled via the damper element during operation according to method sequence d2) upon or immediately after reaching the forming position for the workpiece, but before the forming process. This device-related embodiment corresponds to one or more of the method-related embodiments described above according to method sequence d2), and reference is made in full to the above explanations.

[0069] According to a device embodiment according to claim 10, the handling device has one, i.e. at least one, manipulator and one, i.e. at least one, gripper system connected to the manipulator, wherein the gripper system is connected to the manipulator via an intermediate damping element. The control unit can be configured to control or regulate the manipulator and / or a coupling element in such a way that the gripper system and the manipulator are elastically decoupled via the damping element during operation according to method sequence d1), at least when or immediately after reaching the pre-position for the workpiece, but before the co-movement by the tool, and during the subsequent forming process. This device embodiment corresponds to one or more of the method embodiments described above according to method sequence d1), and additional reference is made in full to the above explanations.

[0070] According to a device embodiment according to claim 10, the device further comprises a preload element, in particular a spring, pneumatic, or hydraulic element, with which the gripper system is or can be supported on or against the manipulator with a variably adjustable or fixed preload force. The preload force can be configured such that, during operation according to method sequence d1), it is at least partially overridden by the moving tool from the time the workpiece is moved along. In one embodiment, the manipulator can be held essentially stationary or motionless at least from the time the workpiece is moved along until the end of the forming process.

[0071] In one embodiment, the control unit can further be configured to control or regulate the preload force when the preload force is variably adjustable, for example, such that the preload force supports the gripper system with the gripped workpiece at rest on the manipulator, at least in the pre-position, and is at least partially overridden during operation according to method sequence d1) as the workpiece is moved along by the moving tool. These device-related embodiments correspond to one or more of the method-related embodiments described above according to method sequence d1), and reference is made in full to the above explanations.

[0072] Embodiments of the invention are described below with reference to the attached figures. They show: FIG. 1 schematically shows a first embodiment of a device for hot forming in a first operating stage; FIG. 2 the device of FIG. 1in a second operating stage; FIG. 3 schematically shows a second embodiment of a device for hot forming in a first operating stage; FIG. 4 the device of FIG. 3 in a second operating stage, and FIG. 5 the device of FIG. 3 in a third operational stage.

[0073] In the figures, identical or functionally identical or functionally analogous elements and components are designated by the same reference numerals.

[0074] Figure 1 shows schematically, at least in sections or in part, a device for hot forming. The device comprises a forming machine 1 and a handling unit 2. The forming machine 1 can be a forming machine, in particular a percussive forming machine, such as a forging hammer, in particular a drop forging hammer.

[0075] The forming machine 1 comprises an upper tool 4 (upper die) coupled to a ram 3, for example, and a lower tool 6 (lower die) coupled to a chabot 5, for example. The operating method for positioning a workpiece described below in connection with a chabot hammer can also be applied to a counterblow hammer and other forming machines.

[0076] In the example shown, the lower tool 6 is stationary and the upper tool 4 can be moved up and down by a lifting movement H and a return stroke movement R. The upper tool 4 moves along a tool movement axis W during the lifting movement H and the return stroke movement R. To carry out a forming cycle, in particular a forging cycle, the ram 3 with the upper tool 4 moves from an upper reversal point in the lifting movement H towards the lower tool 6, with the forming process taking place in the area of ​​the lower reversal point, in which the upper and lower tools interact. From the lower reversal point, the ram 3 with the upper tool 4 moves upwards again in the return stroke movement R and can undergo another forming cycle when the upper reversal point is reached.

[0077] The device further comprises a handling device 7, which is configured and intended to pick up a workpiece 8 from a feeder (not shown) and position it in the working space A of the forming machine 1, hold it during a forming process, and place it on a support (not shown) after the forming process. The handling device 7, comprising, for example, an industrial robot, is responsible for or configured for the (automatic) handling of the workpiece 8.

[0078] The handling device 7 comprises a manipulator 9, for example a robot arm, with a rotary drive 10, from which a manipulator arm 11 extends. The rotary drive 10 enables rotation of the manipulator arm 11 about a rotation axis, which, in the view of the figures, runs parallel to the longitudinal extension of the manipulator arm 11.

[0079] The manipulator arm 11 has a coupling element 12 at its free end. In the present example, the coupling element 12 extends approximately perpendicular to the manipulator arm and has a support surface 20 ( FIG. 2 and FIG. 3 ). In the FIG. 1In the operating state shown, a leg 13 of a gripper system 14 rests on the support surface 20, so that the leg 13 is supported on the manipulator arm 11. The coupling between the coupling element 12 and the leg 13 can comprise a loose resting position (a rigid coupling within the meaning of the application). In embodiments, the coupling can comprise a coupling element or a coupling mechanism with which the leg 13 can be actively mechanically coupled to the manipulator arm 11. For this purpose, the coupling element 12 can, for example, comprise an actively releasable and closable lock. If a coupling element is present, the leg 13 can be coupled to the manipulator arm 11, for example, as part of the movements for feeding and removing workpieces 8, so that the leg 13 is rigidly coupled to the manipulator arm 11. During the forming orDuring a forming cycle, the rigid coupling, if present, is released, so that the manipulator arm 11 is elastically decoupled from the leg 13 via the damper element 15 and, due to the elasticity of the damper element 15, can be tilted to a certain extent relative to the leg 13. The tilting between the leg 13 and the manipulator arm 11 to cancel or establish the rigid coupling is described in more detail below.

[0080] The coupling element 12 is in the FIG. 1 shown operating stage is coupled to the leg 13 (or arm) of the gripper system 14 and rests on the support surface 20, and is therefore rigidly coupled to the leg 13.

[0081] At the end pointing away from the manipulator 9, the gripper system 14 has gripping elements 16 (or: a gripper unit) attached to the leg 13 (not shown in detail), which are designed and provided to grip and hold the workpiece 8, wherein the gripping elements 16 are designed, e.g. with regard to the height and arrangement of the holding or gripping elements 16, so that they can hold the workpiece 8 even during a forming process.

[0082] The leg 13 is coupled to the manipulator arm 11 at the end facing the manipulator 9 via the damper element 15. For example, the damper element 15 can be attached to the manipulator arm 11 on the one hand and to the leg 13 on the other, e.g., by a mechanically fixed or detachable connection. Between the attachment points on the manipulator arm 11 and the leg 13, the damper element 15 has a section with or made of elastic material, which fulfills two functions.

[0083] On the one hand, the damper element 15, due to its elasticity, allows the leg 13 to be tilted relative to the manipulator arm 11. This tiltability makes it possible to keep the leg 13 and the manipulator arm 11 in a first operating state ( FIG. 1 ) via the coupling element 12. Furthermore, it is possible to couple the manipulator arm 11 from the leg 13 in a second operating state ( FIG. 2 , 3 ) elastically decoupled, wherein the leg 13 and the manipulator arm 11 are connected to each other in the second operating state via the damper element 15 and at the same time coupled via the elastic material acting as a damper and / or absorber.

[0084] On the other hand, in the second operating state, the damper element 15 or the elastic material dampens or absorbs mechanical energy, which, when the rigid coupling is released, is transferred from the workpiece 8 to the leg 13 during forming. This damping or absorption reduces, or preferably substantially prevents, the propagation of the mechanical energy transferred via the workpiece 8 to the leg 13 during forming into the manipulator arm 11 and into components mechanically connected thereto. In this way, sensitive components of the manipulator 9 can be protected.

[0085] The damper element 15 can, for example, be designed as a type of rubber bearing, and can have, for example, two opposing metal plates or discs with a block made of rubber or, in general, of an elastic material arranged between them. The metal plates or discs are firmly connected to the block, wherein the metal plates or discs can have attached or integrated fastening elements for screw fastening. By means of the fastening elements, which can be provided on opposite sides of the damper element, such a damper element can be operatively attached, for example, to the leg 13 on the one hand and to the manipulator arm 11 on the other, so that the intermediate block elasto-mechanically decouples the leg 13 and the manipulator arm 11.

[0086] The coupling element 12 and the damper element 15 are attached to the manipulator arm 11 at opposite ends. In the illustrated embodiments, the coupling element 12 is located at the free end of the manipulator arm 11, and the damper element 15 is located at the end facing the rotary drive 10, in the example shown at a predetermined distance from the rotary drive 10. The damper element 15 is attached to the leg 13 at the end facing away from the gripping elements 16.

[0087] The coupling element 12 and the damper element 15 are mounted and arranged so that the gripper system 14, in particular the leg 13, in a first operating position FIG. 1 is rigidly coupled to the manipulator 9, in particular the manipulator arm 11, and that the gripper system 14, in particular the leg 13, in a second operating position according to FIG. 2 (and e.g. the operating positions according to FIG. 3 to FIG. 5) is elastically decoupled from the manipulator 9, in particular the manipulator arm 11. These operating positions will be discussed in more detail below.

[0088] In the elastically decoupled operating position of the FIG. 2the gripper system 14, specifically the leg 13, is only connected to the manipulator arm 11 via the damper element 15. In this operating position, the damper element 15 acts as a damper or absorber element for forces acting on the leg 13 that arise during the forming process, and thus causes an elastic decoupling of the leg 13 from the manipulator arm 11. Without the damper element 15, these forces would be transmitted essentially completely to the manipulator arm 11 and the manipulator 9 as a whole via the leg 13 of the gripper system 14, which holds the workpiece 8 during the forming process, which would or could lead to damage when using conventional or usual manipulators, e.g. industrial robots. In the rigidly coupled operating position, the damper element 15 essentially acts like a fixed bearing, with the leg 13 of the gripper system 14 being rigidly positioned via the coupling element 12.

[0089] During a forming process with the device according to FIG. 1 The manipulator 9 with gripper system 14 positions the workpiece 8 in the working space A of the forming machine 1 in a pre-position V or a waiting position. This positioning can occur, for example, while the ram 3 is executing the return stroke movement R, the ram 3 is in the area of ​​the upper reversal point, and / or in an initial phase of the stroke movement H (working stroke).

[0090] In the pre-position V, the workpiece 8 has a predetermined distance D from the lower tool 6, as well as a distance from the upper tool 4. The distance D is selected such that no significant heat transfer can occur from the workpiece 8 to the lower tool 6. Furthermore, the distance D is selected such that the workpiece 8 is positioned sufficiently close to the lower tool 6 so that, on the one hand, the workpiece 8 is positioned in the pre-position V, i.e. suspended above the lower tool 6, for as long as possible during the lifting movement H, and, on the other hand, the workpiece 8 can be moved into the forming position U ( FIG. 2 ) on the lower tool 6. The distance D between the upper side of the lower tool 6 and the underside of the workpiece 8 can, for example, be in the range between 1 mm and 10 mm, in particular between 1 mm and 5 mm.

[0091] Positioning the workpiece 8 in the pre-position V, for example, such that the workpiece 8 is held suspended, in particular suspended, above the lower tool 6 for as long as possible, has the advantage that the contact time of the warm workpiece 8 with the lower tool 6, i.e., the thermal contact, can be significantly reduced, thereby reducing the cooling or cooling of the workpiece 8 in the period before the forming process. This, in turn, has a beneficial effect, for example, on the forming result.

[0092] To carry out a forming process, the workpiece 8 is transferred into the forming position U on the lower tool 6 by a corresponding movement of the manipulator 9. The transfer to the forming position U can, for example, be triggered or initiated as soon as the ram 3 or the upper tool 4 reaches a, in particular predetermined, reference position P ( FIG. 1 ) reached.

[0093] If the ram reaches 3 or the upper tool reaches 4 (as in FIG. 1 ) the reference position P, which can be determined or recorded, for example, by a (not shown) position measuring system, the handling device 7 is instructed, for example by a (not shown) control unit such as a computer unit, to transfer the workpiece 8 into the forming position. FIG. 2 shows the operating stage in which the workpiece 8 is positioned in the forming position U on the lower tool 6, ie after the handling device 7 has transferred the workpiece 8 from the pre-position V to the forming position U.

[0094] The transfer of the workpiece 8 from the pre-position V to the forming position U takes place synchronously with the movement of the upper tool 4 or ram 3 in the direction of the lower tool 6, wherein the handling device 7 is controlled such that the workpiece 8 precedes the upper tool 4 and the workpiece 8 reaches the forming position U before the upper tool 4 hits the workpiece 8.

[0095] The advance, in particular of the movement control of the handling device 7, and the reference position P are selected or set such that the handling device 7, after reaching the forming position U, still has sufficient time to release the rigid coupling between the manipulator arm 11 and the leg 13 caused by the coupling element 12.

[0096] As can be seen from a summary of the Figures 1 and 2the handling device 7 moves the workpiece 8 parallel to the stroke movement H of the ram 3 downwards into the forming position U on the lower tool 6. This movement is in FIG. 1 indicated by the arrow 17. Immediately after this, ie after placement of the workpiece 8 in the forming position U, the manipulator 9 performs a turning, tilting or rotational movement, indicated by the curved arrow 18 in FIG. 2, wherein the leg 13 and the manipulator arm 11 tilt relative to one another with respect to an imaginary axis of rotation in the region of a tilting point or a tilting axis K in the region of the damper element 15, in particular of the elastic material. Through this or in connection with this turning, tilting, or rotational movement, during which the workpiece 8 remains unchanged in its position on the lower tool 6, the rigid coupling between the leg 13 and the manipulator arm 11 caused by the coupling element 12 is canceled, so that the manipulator arm 11 is elastically decoupled from the leg 13 of the gripper system 14 via the damper element 15.

[0097] After the rigid coupling is released, the ram 3 reaches the forming point U through its continuous further movement parallel to the stroke movement H in the direction of the lower tool 6, and the workpiece 8 is formed accordingly.

[0098] After the forming process, the ram 3 with the upper tool 4 moves in the return stroke movement R to the upper reversal point of the ram 3. After the forming process, the handling device 7, in particular the manipulator arm 11, performs a movement opposite to the above-mentioned turning, tilting or rotational movement, as a result of which the coupling element 12 again rests on the leg 13, or engages and / or is coupled to it. The leg 13 is thereby rigidly coupled again to the manipulator arm 11. In this rigidly coupled operating position, the handling device 7 can perform further movements with the workpiece 8, e.g. repositioning for further forming operations, or the handling device can transfer the formed workpiece 8 to a storage unit. The handling device 7 can then transfer another workpiece 8 to the work space A, with subsequent forming according to the steps described above.

[0099] The described operating mode with positioning in the pre-position and decoupling of the gripper system 14, or the leg 13, from the manipulator arm 11 in the forming position U can be carried out accordingly for each forming process.

[0100] The FIG. 3 to FIG. 5 The second embodiment shown is essentially based on the same forming machine, so that reference is made to the above explanations regarding the forming machine as such.

[0101] The second embodiment differs from the first in the manner of transferring the workpiece 8 into the forming position U, which is described in more detail below, wherein, particularly with regard to the handling unit 2, identical and functionally identical components are designated by the same reference numerals.

[0102] Just as with the first design according to FIGS. 1 and 2 In the second design, FIGS. 3 to 5the workpiece 8 in the pre-position V, in particular initially suspended, in particular suspended at rest, above the lower tool 6 and at the same time spaced from the upper tool 4 ( FIG. 3 ). The subsequent transfer of the workpiece 8 into the forming position ( FIG. 4 and FIG. 5 ) is, however, different from the first design.

[0103] While in the first embodiment the workpiece 8 is moved by the handling device 7 as such and actively by it to the forming position U (also referred to above as process sequence d2), in the second embodiment the transfer of the workpiece 8 from the pre-position V to the forming position U takes place by the moving upper tool 4 (also referred to above as process sequence d1).

[0104] In the example of Figures 3 to 5The handling unit 2 also comprises a handling device 7, a manipulator 9, a rotary drive 10, a manipulator arm 11, and a gripper system 14. The gripper system 14 is coupled to the manipulator arm 11 via a leg 13 via a damper element 15, as in the first embodiment. Analogous to the first embodiment, the damper element 15 elastically decouples the manipulator arm 11 and the gripper system 14 or leg 13, provided there is no rigid coupling between the leg 13 and the coupling element 12. A change between the rigidly coupled and the elastically decoupled position can be achieved, analogous to the first embodiment, by a tilting, pivoting, or rotating movement.

[0105] The Figure 3shows the situation in which the workpiece 8 is suspended above the upper tool 6 in the pre-position V (waiting position) and is still at a distance from the upper tool 4. Due to the movement of the upper tool 4 in the direction of the lifting movement H, it hits the suspended workpiece 8 during the lifting movement H ( FIG. 4 ) and takes it with you. Figure 4 shows the situation in which the workpiece 8 is positioned in the pre-position V, and the upper tool 4 has already moved so far towards the workpiece 8 during the lifting movement H that the upper tool 4 carries the workpiece 8 along with it during further movement. By carrying the workpiece 8 along from the pre-position V and reaches the forming position U after covering the distance D, as in FIG. 5 shown. By further downward movement of the upper tool 4, the workpiece 8 is formed.

[0106] To prevent the manipulator arm 11 and the manipulator 9 from being damaged when carrying the workpiece 8, the handling device 7 of the second embodiment has a preloading element 19, which is arranged in the longitudinal extension of the manipulator arm 11 between the damper element 15 and the end of the manipulator arm 11 facing away from the damper element 15, corresponding to the end at which the coupling element 12 is present in the embodiment shown. In variants of the second embodiment, it is possible to use a manipulator arm 11 without a coupling element 12.

[0107] The preload force of the preload element 19 is adjusted so that it absorbs the weight of the gripper system 14 with leg 13 and tool 8, and holds the leg 13 with the workpiece 8 held by the gripper system 14 at a distance from the manipulator arm 11, in particular can hold it in a floating position.

[0108] The preload element 19 is designed in the exemplary embodiment as a pneumatic or hydraulic element that is arranged between the manipulator arm 11 and the leg 13 and is connected to them. Such preload elements 19 enable a variable adjustment of the preload force and thus, for example, an adaptation of the preload force to the weight of the gripper system 14 and the workpiece 8 or to the torque generated by them with respect to the tilt axis K. If the handling unit 2 of the second embodiment provides a rigid coupling, the manipulator arm 11 can comprise a coupling element 12, analogous to the first embodiment. In this case, a variably adjustable preload element 19 can be provided, which is or can be operated such that, for example, by reducing the preload force, the leg 13 can be or is rigidly coupled to the coupling element 12 when the workpiece 8 is gripped in a first operating state, and that, for exampleBy increasing the preload force, the leg 13 is no longer rigidly coupled to the coupling element 12 in a second operating state when the workpiece 8 is gripped, and the leg 13 is elastically decoupled from the manipulator arm 11 via the damper element 15. In the rigidly coupled state, the leg 13 can rest on the support surface 20, and in the decoupled state, the leg 13 can be lifted off the support surface 20.

[0109] In addition, a suitably configured hydraulic or pneumatic preload element 19 can produce a damping effect that supports the damper element 15.

[0110] The preload element 19 is configured to generate a variable preload force acting between the point of application on the manipulator arm 11 and the point of application on the leg 13. As a result, the leg 13, and with it the entire gripper system 14, is supported against the manipulator arm 11, so that the gripper system 14 with the workpiece 8 can be stably positioned by the action of the preload force, for example, in the pre-position V, suspended above the lower tool 6.

[0111] The preloading element 19 and the preload force are in the embodiment according to FIGS. 3 to 5designed or adjusted in such a way that the preload force can be overridden when the workpiece 8 is carried by the upper tool 4. During override, the preload element 19 is compressed, whereby the leg 13 can move or rotate in the direction of the manipulator arm 11 due to the elastomechanical properties of the damper element 15. In other words, the angle between the manipulator arm 11 and the leg 13 decreases until the carried workpiece 8 rests on the lower tool 6 in the forming position U. The length of the pre-tensioning element 19, and thus the distance between the leg 13 and the manipulator arm 11 or the coupling element 12, is selected such that even after over-pressing there is no rigid coupling between the leg 13 and the manipulator arm 11 or the coupling element 12, ie that the manipulator arm 11 and the leg 13 continue to be elastically decoupled.

[0112] This makes it possible for the manipulator arm 11 not to follow the driving movement and to remain stationary and at the same time elastically decoupled from the leg 13, at least for the period from the driving to the forming point U and during the forming.

[0113] After the forming, the upper tool 4 moves in the return stroke R and the pre-tensioning element 19 can, due to the effect of the pre-tensioning force, again assume the non-over-pressed shape, whereby, for example, the workpiece is lifted from the lower tool 6.

[0114] In the second embodiment, it can be provided that the handling unit 2 or the handling device 7, analogously to the first embodiment, is configured such that the gripper system 14 and the manipulator arm 11 are rigidly coupled in an operating state by tilting, pivoting or rotating the manipulator arm 11 and / or by adjusting or changing the pretensioning force of the pretensioning element 19.

[0115] However, the previously described active decoupling or coupling in the second embodiment according to FIGS. 3 to 5 not absolutely necessary if, for example, the pre-tensioning force of the pre-tensioning element 19 is selected or set or adjustable in such a way that in the non-over-compressed state a quasi-rigid coupling is provided in which the pre-tensioning force is greater than the weight of the gripper system 14 and the workpiece 8 acting on the pre-tensioning element 19.

[0116] Apart from hydraulically or pneumatically adjustable preload elements 19, preload elements 19 with non-adjustable preload force can also be considered, such as spring elements.

[0117] It is understood that the handling unit 2 or the handling device 7 of the second embodiment can also be used in the operating mode described in connection with the first embodiment. Mixed forms are also possible, in which the workpiece 8 is transferred to the forming position U by lowering the handling device 7 and the workpiece 8 being carried along at least part of the way by the upper tool 4. As already indicated, these operating modes can also be used with counterblow hammers, in which both tools move.

[0118] The above statements show that, with the invention described herein, cooling or cooling down of the workpiece during hot forming prior to the forming process can be reduced by reducing the contact time between the workpiece and the tools. In particular, this allows for better forming results. Furthermore, a shorter contact time between the workpiece and the tool(s) can reduce the heat input into the tools. List of reference symbols

[0119] 1Forming machine 2Handling unit 3Bear 4Upper tool 5Scabbard 6Lower tool 7Handling device 8Workpiece 9Manipulator 10 11Rotary drive Manipulator arm 12Coupling element 13Leg 14Gripper system 15Damper element 16Gripping element 17Arrow, parallel movement 18Arrow, rotary movement 19Pre-tensioning element 20Support surface AWorking space DDistance HStroke movement KKipping axis PReference position RReturn stroke movement UForming position VPreposition WTool movement axis

Claims

1. Method for hot forming, in particular for forging, a workpiece (8), in which a) the workpiece (8) is formed during a working stroke (H) in a working room (A) of two tools (4, 6) of a forming machine (1) which are moved towards each other in a forming process, and b) the workpiece (8) is held during the forming process in a forming position (U) located in the working room (A) by means of a handling device (7), whereby c) the handling device (7) pre-positions the workpiece (8) in the working room (A) in a predetermined pre-position (V) at a distance from the tools (4, 6) before the forming process, and whereby d1) the workpiece (8) pre-positioned in the pre-position (V) is moved from the pre-position (V) to the forming position (U) by a tool (4) moved in the working stroke (H) along a tool movement axis (W) to the forming position (U), and / or d2) the workpiece (8) pre-positioned in the pre-position (V) is moved to the forming position (U) by the handling device (7) in a movement synchronised with a tool (4) moved in the working stroke (H) along a tool movement axis (W) to the forming position (U); whereby e) the handling device (7) comprises a gripper system (14) and a manipulator (9) designed for the spatial movement of the gripper system (14), the gripper system (14) being connected to the manipulator (9) via an interposed damper element (15), and f) the gripper system (14) is or becomes elastically decoupled from the manipulator (9) via the damper element (15) when the workpiece (8) is pre-positioned, characterised in that the gripper system (14) is supported or gets supported at least in the pre-position of the workpiece (8) by a preload element (19) with a variably adjustable or a fixed preload force on or against the manipulator (9).

2. Method according to claim 1, wherein the workpiece (8) in the pre-position (V), but at least upon reaching the pre-position (V), has a predetermined distance (D) from the forming position (U) and / or a predetermined distance (D) from a stationary tool (6) in the direction of a tool movement axis (W) along which the moving tool (4) moves.

3. Method according to any one of claims 1 or 2, wherein the synchronous movement in step d2) is executed and / or triggered as soon as the tool (4), which is moved towards the forming position (U), reaches a reference position (P) in the working stroke (H), wherein the synchronous movement is preferably executed in such a way that the workpiece (8) reaches the forming position (U) before the tool (4) acts on the workpiece (8) for forming.

4. Method according to any one of claims 1 to 3, wherein an alignment of the workpiece (8) in the pre-position (V) corresponds to an alignment intended for the forming position (U) except for a displacement or movement parallel to the tool movement axis (W).

5. Method according to claim 1, wherein the handling device (7) is operated or can be operated in such a way that - the gripper system (14) is or becomes elastically decoupled at least immediately before the co-movement by the tool (8) in step d1).

6. Method according to claim 5, wherein the pretensioning force is at least partially overpressed by the moving tool (4) when the pre-positioned workpiece (8) is moved along after step d1).

7. Method according to claim 1, wherein the workpiece (8) is placed on a tool (6) by the synchronous movement to the forming position (U), and wherein, with the workpiece (8) in place, the handling device (7) is operated in such a way that the manipulator (9) is or is at least partially elastically decoupled from the gripper system (14) immediately before and during the forming process via the damper element (15).

8. Method according to claim 1 or according to any one of claims 5 to 7, wherein the handling device (7) is operated in such a way that the gripper system (14) and the manipulator (9) are substantially rigidly coupled by a rigid coupling before the workpiece (8) is positioned in the pre-position (V) and / or after the forming operation has taken place.

9. Method according to claim 8, wherein an adjustment of the rigid coupling and / or a release of the rigid coupling between the gripper system (14) and the manipulator (9) is effected by movements of the manipulator (9) relative to the gripper system (14) which are substantially complementary to one another and / or by movements of a coupling element (12) which are substantially complementary to one another, wherein the gripper system (14) preferably is or remains substantially stationary during the setting and / or releasing of the rigid coupling, and wherein the movement of the manipulator (9) relative to the gripper system (14) preferably comprises swivelling and / or angling.

10. Apparatus for hot forming, in particular forging, a workpiece, in particular for use in one of the methods according to any one of claims 1 to 9, comprising a) a forming machine (1), in particular an impact forming machine, having at least two tools (4, 6) which can be moved relative to one another for carrying out a forming operation during a working stroke (H) in a working room (A) of the tools (4, 6); b) a handling device (7) for handling workpieces (8), which is set up to grip and / or hold the workpiece (8) even during the forming process; c) at least one control unit for controlling and / or regulating the movements of the tools (4, 6) and of the handling device (7), the control unit being set up to control or regulate at least the handling device (7) in such a way that d) the workpiece (8) is pre-positioned in the working room (A) in a predetermined pre-position (V) at a distance from the tools (4, 6) prior to the forming process, and d1) the workpiece (8) pre-positioned in the pre-position (V) is moved from the pre-position (V) to the forming position (U) by a tool (8) moved in the working stroke (H) to the forming point (U), the workpiece (8) being held by the handling device (7) during the movement and the forming process; and / or d2) the handling device (7) moves the workpiece (8) from the pre-position (V) to the forming position (U) in a movement synchronised with a tool (4) moved in the working stroke (A) to the forming position (U) as soon as the tool (4) moved towards the forming position (U) reaches a reference position (P) in the working stroke (A), the workpiece (8) being held by the handling device (7) during the forming process (U), e) wherein the handling device (7) comprises a manipulator (9) and a gripper system (14) connected to the manipulator (9), wherein the gripper system (14) is connected to the manipulator (9) via an interposed damper element (15), characterised in that f) the device further comprises a preload element (19) with which the gripper system (14) can be supported on or against the manipulator (9) with a variably adjustable or a fixed preload force, and in that g) the control unit is furthermore set up to elastically decouple the gripper system (14) from the manipulator (9) via the damper element (15) when the workpiece (8) is pre-positioned, the gripper system (14) being supported on or against the manipulator (9) by the preload element (19) with the variably adjustable or fixed preload force at least in the pre-position of the workpiece (8).

11. Apparatus according to claim 10, wherein the control unit is set up to control or regulate the manipulator (9) and / or a coupling element (12) in such a way that the gripper system (14) and the manipulator (9) are elastically decoupled via the damper element (15) during operation according to d2) at or immediately after reaching the forming position (U) for the workpiece (8), but before the forming process.

12. Apparatus according to claim 10, wherein the control unit is set up to control or regulate the manipulator (9) and / or a coupling element (12) in such a way that the gripper system (14) and the manipulator (9) are elastically decoupled via the damper element (15) during operation according to d1) at least at or immediately after reaching the pre-position (V) for the workpiece (8), but before the co-movement by the tool (4).

13. Apparatus according to claim 11 or 12, wherein the pretensioning force is set up in such a way that it is at least partially overpressed by the moving tool (4) during operation according to d1) from the movement of the workpiece (8), and wherein, preferably, the manipulator (9) is or is held essentially motionless at least from the movement until the end of the forming process, wherein the control unit is preferably furthermore set up to control or regulate the pretensioning force in the case of a variably adjustable pretensioning force, such that the pretensioning force at least in the pre-position (V) wherein the control unit is preferably furthermore set up to control or regulate the gripper system (14) with workpiece (8) in the case of variably adjustable pretensioning force in such a way that the pretensioning force at least in the pre-position (V) supports the gripper system (14) with workpiece (8) resting on the manipulator (9), in particular with a pretensioning force, and in operation according to d1) is at least partially overpressed by the moving tool from the movement of the workpiece (8).

14. Apparatus according to any one of claims 10 to 13, wherein the preload element (19) is a spring, pneumatic or hydraulic element.

15. Apparatus according to any one of claims 11 to 14, wherein the forming machine (1), the handling device (7) and the at least one control unit are arranged to carry out a method according to any one of claims 1 to 10.

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