Device for a clamping system

Abstract

The invention relates to a device for retrofitting for a clamping system, in particular for a vice, wherein the device has - a connection structure for connecting the device to the clamping system, - an electric drive for providing a mechanical force, - a control stage for controlling the electric drive and - a force transmission structure for transmitting the mechanical force provided by the electric drive to the clamping system, wherein the device is designed to transmit the force provided by the electric drive to the clamping system via the force transmission structure for clamping a workpiece in the clamping system.

Description

[0001] title

[0002] Device for a clamping system

[0003] Description

[0004] Technical field

[0005] The invention relates to a device for retrofitting a clamping system.

[0006] background

[0007] There has always been a desire for automation in manufacturing. In recent years, machine tools such as machining centers have become so automated that the production steps, from the moment the material to be machined is clamped into the machine tool to the moment the finished workpiece or semi-finished product can be removed from the machine tool, are carried out automatically. However, this automation has left a gap in the automation of the workpiece clamping process, so that today, a considerable portion of manual labor in largely automated production is spent on correctly clamping and removing the workpiece.Attempts to close this automation gap, as is known, for example, from DE 20 2021 105 213 Ul, which discloses a mobile, electrically operated clamping device, in particular a vice, have so far failed in practice because the effort and costs for converting to the electrically operated clamping device and the associated restrictions (e.g. structural conditions) are not offset by the advantages of automation.

[0008] The invention therefore has for its object to provide a device and a system which eliminates the aforementioned problems.

[0009] Summary of the invention This object is achieved by a device according to claim 1. The subject matter of the invention is therefore a device for retrofitting a clamping system, in particular for a vice, wherein the device has a connecting structure for connecting the device to the clamping system, an electric drive for providing a mechanical force, a control stage for controlling the electric drive and a force transmission structure for transmitting the mechanical force provided by the electric drive to the clamping system, wherein the device is designed to transmit a mechanical force provided by the electric drive via the force transmission structure to the clamping system for clamping a workpiece in the clamping system.

[0010] This object is further achieved by a system for clamping a workpiece in a clamping system according to claim 15. The invention therefore relates to a system for clamping a workpiece in a clamping system, wherein the system comprises a device according to the invention and a clamping system, in particular a vice, wherein the device is connected to the clamping system by means of a connecting structure.

[0011] The measures according to the invention have the advantage of closing the automation gap in clamping workpieces using a clamping system (i.e., a clamping device). This occurs without significant financial, material, or time expenditure, because the device according to the invention can be easily connected to the clamping system, in particular to a standard vise, and provides all the necessary measures and resources to operate the clamping system automatically.

[0012] A clamping system, which in some cases is also referred to as a clamping device, is a mechanism for securing a workpiece. In some cases, the clamping system can also be intended for securing a tool. It is therefore a clamping system for production. Such a clamping system and the fixture can also be used for hand tool machining, because here too, automated clamping promotes production efficiency. The clamping system and the fixture are preferably used together with machining tools so that the synergistic effects of the successive automated work steps can be optimally utilized. Nowadays, the clamping system is mainly used in machine tools, but also in primary forming machines and forming machines, which is why the fixture is preferably designed for these work environments.The device according to the invention can be designed for retrofitting to various clamping systems. For example, the device can be designed for a clamping system for clamping slabs. Particularly preferably, the device is designed for retrofitting to a vice.

[0013] Further, particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description.

[0014] The device can therefore be designed for retrofitting to different clamping systems and is preferably designed for vices.

[0015] Such a vise can be constructed, for example, as follows: a pull spindle moves a spindle nut, designed as a hollow shaft and coupled to a mobile jaw, by rotating it (depending on the direction) toward or away from a stationary jaw. Within the pull spindle is a force amplification mechanism, or force amplifier for short. Such a force amplifier has a wedge bolt in a force amplifier housing (which can be designed as part of the pull spindle), which presses against pressure elements (e.g., pressure rollers) located between the force amplifier housing and a support body, so that these are pressed against the force amplifier housing and spread apart when the wedge bolt is pushed between the pressure elements. (It should be noted that the pressure elements are sometimes also referred to as force amplifiers in the technical literature.)The wedge bolt is positioned along an axis with the tension spindle and the wedge bolt. A shaft (pressure spindle) with a disengagement clutch is connected to the wedge bolt along the axis. Springs (e.g. disc springs) are located around the axis between the force amplifier and the disengagement clutch to apply a spring force to the mobile jaw. The shaft (pressure spindle) is mounted on a thread so that disengagement of the disengagement clutch leads to a screwing movement of the shaft (pressure spindle). If the disengagement clutch is now driven, traditionally by a crank or by using the device according to the invention, the mobile jaw moves towards the stationary jaw until it contacts a workpiece located between them.After contact with the workpiece, the disengaging clutch releases when a certain load is exceeded. Following the screwing motion, the shaft (pressure spindle) presses against the wedge bolt, which spreads the pressure elements. This causes the support element to be pressed against the springs. A spring force, via the force amplifier housing and the spindle nut, presses the movable jaw against the workpiece. By further moving the wedge bolt between the pressure elements, the clamping force is precisely increased.

[0016] In addition to the vice discussed here, there are of course a variety of other designs of clamping systems for which the device can be easily adapted by the specialist.

[0017] The device can drive the clamping system, for example, the vise, at different points using a power transmission structure. For example, the drive of the disengaging clutch is advantageous in the vise discussed above. However, the device itself is particularly preferably equipped with the disengaging clutch, which, depending on the mode (i.e., whether it is engaged or not), drives the spindle nut and actuates the force amplifier via the shaft (as a pressure spindle).

[0018] The control stage of the device can be implemented using hardware and / or software. For example, the control stage can have a switch or button that closes an electrical circuit so that the electric drive is supplied with electrical energy. However, the control stage can also have an integrated circuit, for example, or be implemented using software in an integrated circuit. The control stage can be designed to control the electric drive depending on control variables, i.e. to supply it with electricity in such a way that the electric drive produces the desired effect. These control variables can be provided, for example, by pressing or releasing a switch or button. However, they can also be provided by the electric drive itself or other entities.The control variables can also be provided externally, i.e. from outside the device, as will be discussed in detail in the relevant section.

[0019] The force transmission structure is designed to transmit a force to the clamping system when the device is connected (mechanically fixed to each other) to the clamping system. Depending on the design of the clamping system, this can be a single force. Usually, a force pair and thus a torque are transmitted. In this case, it can also be referred to as a torque transmission structure. The force transmission structure can also be understood as a power transmission structure that delivers power input on the drive side to the output side.

[0020] It is therefore preferably a device for retrofitting a clamping system, in particular for a vice, wherein the device has the connecting structure for connecting the device to the clamping system, an electric drive for providing a mechanical power, a control stage for controlling the electric drive and a power transmission structure for transmitting the mechanical power provided by the electric drive to the clamping system, wherein the device is designed to transmit the power provided by the electric drive via the power transmission structure to the clamping system for clamping a workpiece in the clamping system.

[0021] The device can be used with the clamping system as the system. However, the device is preferably used as a retrofit kit. The device is therefore preferably a retrofit kit for driving the clamping system.

[0022] The fixture can be powered by a wired electrical power supply. This allows for low-maintenance operation of the fixture and clamping system once installed. However, it has been shown that a wired power supply has some disadvantages, as installation is complicated by cabling and the required power peaks require cables with a considerable cross-section. For example, depending on the configuration and other requirements, it may be necessary to use cables with a cross-section of 4 mm for standard vises with 125 mm jaws, which require a clamping force of up to 40 kN. 2to provide the necessary electrical power with the necessary safety. However, such cabling severely limits the flexibility in positioning or installing the vise and also hinders the movement of the tool. Furthermore, the increasing complexity of the machine being retrofitted (especially machine tools) makes cabling more complex and time-consuming. Especially when there are infinitely pivoting axes (e.g., CNC milling machines with a turning option or lathes), cabling is nearly impossible or only possible with wear-prone and / or bulky components. This makes cabling in a 5-axis CNC, for example, problematic.

[0023] It has therefore proven advantageous for the device to have an energy storage module, in particular a replaceable one, for providing the electrical power for the electric drive. The energy storage module preferably has an electrical energy storage device, for example a supercapacitor, a battery and / or preferably an accumulator, for providing the electrical power for the electric drive. It has been shown that such energy storage modules can provide the short-term power peaks required without requiring a large amount of structural space. This measure thus enables simple and space-saving installation of the device without the need for external cabling (i.e., an externally cable-free installation) of the device, i.e., without requiring any space in the vicinity of the device, as well as a space-saving design of the device itself.

[0024] According to a preferred embodiment, the device can be implemented with the energy storage module completely wirelessly to the environment. Preferably, the entire system for clamping a workpiece is completely wireless to the environment.

[0025] A particularly advantageous power supply can be achieved through the use of an energy storage module comprising a lithium-ion battery or a lithium-polymer battery, etc. The lithium-ion battery can withstand particularly high power peaks, thus providing the required torque to drive the clamping system via the power transmission structure and subsequently to clamp the workpiece. After clamping, no further force, torque, or power is required because the clamping system maintains the clamping force due to its self-locking mechanism.

[0026] In rechargeable batteries or batteries, multiple cells can be connected in series and / or parallel to achieve the desired power delivery characteristics. These can be connected in parallel and / or series as needed, i.e., they can be realized from a single cell or multiple cells connected in parallel and / or series.

[0027] The energy storage device can comprise rechargeable batteries and be designed to be charged via a wired connection and / or wireless power transmission, for example, inductively. This allows for a simple power supply to the device. The device can also be designed to exchange data, particularly regarding the charge state, via wireless power transmission. Thus, information, particularly that required for optimized energy charging, can be transmitted compactly, without the need for additional components.

[0028] It has proven particularly advantageous for the energy storage module to be replaceable or to have replaceable energy storage submodules. This allows for rapid restoration of operational readiness and thus virtually uninterrupted use of the devices. Preferably, the energy storage module is designed to "sustain" at least one shift operation, i.e., to provide the energy for the clamping and release processes required during a shift. Thus, the replacement can be combined with the shift change, so that no time delay occurs at all. For example, experiments by the applicant have shown that for two-shift operation for clamping forces of up to 40 kN with clamping processes every two minutes over 16 hours, a 5 Ah battery (for example, with 18 V and lithium-ion batteries) provides the necessary energy without taking up much space.Correspondingly larger or smaller capacities can be used for different shift durations or desired application scenarios. Such a battery is recharged in approximately 1 / 2 h. It should be noted that "replaceable" here refers to reversible removal. This means that the corresponding object (i.e., the energy storage module or the energy storage submodule) can be removed and reinserted without removing an irreversible connection, in particular an irreversible material connection. In particular, the device is configured such that the energy storage module is replaceable in the retrofitted state, i.e., in the state in which the device is mechanically connected to the clamping system.

[0029] The connecting structure is preferably independent of the force transmission structure. Thus, there is preferably a connecting structure for the stationary connection of the device to the clamping system and a force transmission structure for the dynamic, i.e., time-variable, transmission of force to the clamping system.

[0030] The energy storage submodule can be the accumulator or the battery. The energy storage module can comprise several such energy storage submodules. For example, battery cells or accumulator cells can be used as the energy storage submodule. The energy storage submodule can also comprise additional components, such as an electronic circuit, in particular short-circuit protection, a charge control, overload protection, and / or a battery management system, to regulate the power supply.

[0031] The device and / or the energy storage module can also be designed so that the energy storage module can be charged via a wired connection and / or wireless energy transmission. In this case, the energy storage module can also be removable.

[0032] The connecting structure can be designed for irreversibly connecting the device to the clamping system. For example, the connecting structure can comprise rivets, one-way screws, or shear bolts. Thus, the device can be irreversibly retrofitted to the clamping system to such an extent that the resulting system for clamping the workpiece in the clamping system cannot be separated by unauthorized persons using standard tools. However, the device is preferably designed for reversible connection to the clamping system, in particular by means of a screw connection.

[0033] A reversible connection is one that can be released using standard tools, such as a screwdriver or open-end wrench, or by hand. A reversible connection can be a screw connection, for example. The connection structure can have holes for this purpose, for example, that allow the device to be screwed to the clamping system. Furthermore, the connection structure can have a contact surface for contacting the clamping system, so that shear forces can be absorbed via this contact surface due to friction.

[0034] Preferably, the device is designed to support a torque transmitted to the clamping system by means of the force transmission structure via the connecting structure. This can be achieved, for example, via the reversible connection. For example, the torque can be supported via the screw connection and the contact surfaces. Supporting the torque of the force transmission structure via the connecting structure creates a compact and torsion-free force or torque transmission from the device to the clamping system, thus enabling precise operation of the clamping system, i.e., precise provision of the force or torque.

[0035] In most cases, a coolant is involved in manufacturing. It has proven advantageous for the fixture to be shaped in such a way that the coolant flow from the clamping system is unobstructed. This ensures optimal cooling of the workpiece to be machined. The fixture is therefore preferably shaped in such a way that it can be attached to the clamping system in such a way that a coolant flow path is created between the fixture and the clamping system, or at least in certain areas around the fixture, and / or the coolant flow path of the clamping system remains unobstructed.

[0036] The device is preferably designed to be sealed, particularly liquid-tight, preferably watertight. For this purpose, seals can be provided, for example, and / or appropriate gap dimensions can be selected to ensure such tightness. This allows the device to be used in the vicinity of the coolant and thus directly at the clamping location. For example, no drive elements need to be removed from the work area prior to operation. The device is preferably designed to be sealed to IP68 protection class, which means that the device can be used even with intensive use of coolant. This can be achieved with the aforementioned measures, resulting in a system for clamping the workpiece that can be used independently even under extreme conditions.

[0037] The machining area of ​​a machine tool (or primary forming machine or metal forming machine) is usually structurally limited. Increasing the machining area usually involves purchasing a larger machine. Therefore, the goal is to maximize the machining area.

[0038] It has therefore proven advantageous that the device is designed in such a way that the force transmission structure is designed to transmit a torque to the clamping system about an axis, wherein the device has a width that runs axially to this axis and a longitudinal dimension that is normal to this axis, wherein the longitudinal dimension is longer than the width. The device therefore forms a T-shape with this axis. This measure allows the machining area to be used optimally because the device can be attached to one end of the clamping system, viewed along the axis, whereby the workpiece to be machined remains undisturbed by the device, without the device itself or the clamping system having to protrude further into the machining area, as would be the case, for example, by raising or lowering the workpiece.Raising the clamping system to accommodate the device relative to a lower boundary surface of the machine, for example a support surface of a machine table, would be the case.

[0039] Furthermore, it has proven advantageous for the device to have a vertical extension that is perpendicular to the width and length, with the vertical extension being smaller than the length. This allows for further optimization of the machining area. Against this background, it has proven advantageous for the vertical extension to be smaller than, or at most equal to, the corresponding vertical extension of the clamping system to be retrofitted. The maximum vertical extension of the system for clamping a workpiece in a clamping system therefore preferably corresponds to the maximum vertical extension of the clamping system.

[0040] Preferably, the device is shaped in such a way that it can be attached to the clamping system without exceeding the interference contour of the clamping system in the height direction, so that the machining area remains as undisturbed as possible, i.e. essentially corresponds, at least in the relevant height direction, to that which would exist without the device.

[0041] The device preferably has a housing, preferably a metal housing, particularly preferably an aluminum housing. This housing preferably encloses the connecting structure, the electric drive, and the power transmission structure at least partially, preferably completely. The use of a metal housing, and in particular an aluminum housing, allows cooling of the device or its components simply through the material properties, which is particularly advantageous when the device comes into contact with coolant, for example.

[0042] The housing is preferably designed to be tight, in particular liquid-tight, preferably waterproof.

[0043] The device preferably has at least one cover in some areas, which covers at least one opening in the device's housing. The cover can also be made of metal. Preferably, the cover is made of a non-metallic material, in particular a polymer. This allows for simple assembly and production of the device.

[0044] According to one aspect of the invention, the device has a surrounding shape designed to encompass the clamping system in certain areas. This allows for a compact design of the device and further optimizes the utilization of the machining area. Furthermore, this measure allows the connection structure to be designed in such a way that the device can be connected to the clamping system at more distant areas. This enables a more stable connection due to the extended lever arm when absorbing force and, furthermore, enables more precise operation of the clamping system.

[0045] Here, the device can be designed to encompass the clamping system on one end face and / or on one, two or three other sides. The end face preferably runs perpendicular to the axis around which the torque can be transmitted to the clamping system. More sides that are encompassed offer the advantage that the connecting structure can be designed to be correspondingly stabilizing and that the components of the device can be accommodated in a compact design. Fewer sides that are encompassed offer the advantage that the machining area remains free at these points. It has therefore proven particularly advantageous if the device is designed to encompass the clamping system on one end face and on one or two other sides.

[0046] The device can therefore be designed to voluminously encompass the clamping system on several sides. To optimally utilize the machining area, it has proven advantageous to enclose the clamping system in a single plane. As mentioned above, it has proven advantageous to enclose the device flatly, so that the machining area remains largely free at the top.

[0047] The device is therefore preferably designed for flat attachment to the clamping system, i.e. in such a way that the machining area is not restricted in height at all or only slightly.

[0048] According to a further embodiment, it has also proven advantageous for the device to be designed to grip around the clamping system upwards and / or downwards. For this purpose, the device has, for example, an attachment which, in the retrofitted state, is located above and / or below the clamping system, in particular grips around the clamping system. This is particularly interesting for machines which have multiple movable axes, i.e. in particular more than three movable axes, for example in a five-axis machine. Here, the accessibility of the workpiece from different directions becomes paramount. Such a high embodiment has proven advantageous because it ensures particularly good accessibility of the workpiece.In both the high and the flat design, it has proven advantageous for the device to have at least one L-shaped extension or to be L-shaped in order to make optimal use of the processing area.

[0049] In this context, it has proven particularly advantageous for the device to have two L-shaped extensions or to be double-L-shaped or U-shaped.

[0050] An L-shaped extension can have an L-shaped housing part, or a housing part that is connected in an L-shape to the rest of the housing of the device.

[0051] Preferably, the two L-shaped extensions are located in a plane with the axis around which the torque is transmitted to the clamping system.

[0052] These measures allow free movement of the movable jaw of the clamping system without being hindered by the device, because the housing parts can then run or extend to the left and right sides of the movable jaw below this movable jaw.

[0053] Preferably, the electric drive is located at least partially in the L-shaped extension. This allows both the electric drive itself and the downstream power transmission structure to be compactly designed and positioned without interference, particularly for the movable jaw.

[0054] It has also proven advantageous to have a common side of the power transmission structure, housing the drive and output sides. This allows the device to be implemented compactly because the force flow is "redirected" in such a way that the available space around the clamping system can be optimally utilized.

[0055] It has proven particularly advantageous that the drive side and the output side face the clamping system in the retrofitted state. Particularly preferably, the electric drive is located on the same side of the power transmission structure on which the clamping system can be connected to the device. If the device includes the energy storage module, it has also proven advantageous for the energy storage module to be located at least partially in the L-shaped extension.

[0056] The device preferably comprises the energy storage module, comprising the electrical energy storage device, preferably an accumulator, for providing the electrical power for the electric drive, wherein the L-shaped extension is designed to be divisible and / or removable, such that the energy storage module or the energy storage submodule is replaceable when the extension is split and / or removed. Thus, the device can be implemented compactly, while simultaneously enabling easy replacement of the energy source. The housing part of the divisible L-shaped extension is preferably designed to be liquid-tight or watertight. This allows for the unrestricted use of cooling fluid.

[0057] In summary, it is advantageous that the electric drive and / or the energy storage module in the device is partially located in the L-shaped extension.

[0058] The housing or the device is preferably hermetically closed or sealed at least in part, in particular completely, at least in the retrofitted state, i.e. when the device is attached to the clamping system.

[0059] Preferably, at least a part of the force transmission structure protrudes from the housing and / or the housing is designed to at least partially accommodate a part of the clamping system, in particular a force-transmitting shaft.

[0060] The device is preferably shaped such that it has a recess for receiving the clamping system, wherein the energy storage module is particularly preferably located on one side next to the recess and the electric drive is particularly preferably located on the other side next to the recess.

[0061] The power transmission structure may include different types of gears, gear stages and / or couplings, etc. to transmit the mechanical power to the clamping system.

[0062] According to one aspect, the force transmission structure is preferably designed to transmit torque to a shaft and to allow axial displacement of the shaft. The shaft transmits the torque about an axis, in particular about the axis of the shaft. The axial displacement of the shaft is unhindered. The shaft can be an element of the retrofit kit or the clamping system. The device, particularly preferably the clamping system itself, preferably comprises the shaft. Multiple shafts can also be used here, wherein these can in particular be mounted about a common axis. For example, an inner shaft and an outer shaft are usually used, which extend into one another. For example, in the vise discussed at the beginning, the pressure spindle forms a shaft, the spindle nut and the tension spindle each form a shaft, which can be driven depending on the embodiment.The force transmission structure is preferably designed at least to allow axial displacement of the shaft that is connected to the clamping system or to which the force transmission structure is connected.

[0063] This measure allows the clamping system to be driven without the position of the fixture itself having to change, i.e. without movement of the fixture housing relative to the clamping system, or without any constraints occurring between the fixture and the clamping system, which subsequently leads to wear. This measure therefore results in smooth and trouble-free drive of the clamping system by means of the fixture. When using the vise discussed at the beginning, there is the further advantage that the force amplifier (force amplifier mechanism), which is located around the axis of the shaft, can be activated without the position of the fixture itself having to change in relation to the clamping system, i.e. without movement of the fixture housing relative to the clamping system. Such a force amplifier therefore makes it possible to generate a clamping force of over 40 kN with a torque of 30 Nm, for example.Because the clamping system is self-locking, these 30 Nm only need to be applied briefly for the clamping process. The short-term power peaks required for this can be easily provided for the required time using the energy storage module discussed above, in particular the lithium-ion battery. After clamping, the activation of the force amplifier means that no further torque is required from the device to the clamping system to keep the workpiece clamped in the clamping system. Thus, no electrical power is required to maintain the clamping force after clamping. This measure thus continues to allow optimal utilization of the power delivery characteristics of the energy supply, specifically the energy storage module.

[0064] It should be noted that the device can also comprise the force amplifier or the force amplification mechanism, as well as preferably also the other components of the force amplification. In this case, the force transmission structure preferably comprises the force amplifier. This allows for particularly optimal adaptation of the device because the force amplifier, the force transmission structure or the remaining components of the force transmission structure and the electric drive, as well as the energy storage module if applicable, can be optimally coordinated with one another. In this case, in order to retrofit or couple the clamping system to the device, if this clamping system is designed as standard, the force amplifier installed in the clamping system may need to be removed and replaced with that of the device.

[0065] In order to ensure particularly simple installation or retrofitting, it is advantageous that the device is designed to drive the force amplifier of the clamping system.

[0066] The power transmission structure can, for example, comprise a gear train, in particular a toothed wheel drive or a friction wheel drive. A toothed wheel drive has proven particularly advantageous in this case due to its precise and slip-free transmission ratio. A friction wheel drive has the advantage of being simpler to implement in many cases. To achieve the axial displacement, straight-toothed gears and / or splined shafts can be used, each of which ensures axial displacement of the shaft.

[0067] It has proven advantageous for the power transmission structure to include a traction drive, in particular a belt drive. This allows for a space-saving, yet simple and cost-effective power transmission. The traction drive also allows for a simple arrangement of the drive side and the output side of the power transmission structure on a common side, particularly with the drive side and the output side facing the tensioning system in the retrofitted state. This can be achieved by using a traction drive with only one gear stage.

[0068] The power transmission structure preferably includes a traction mechanism for providing axial displacement of the shaft. This allows for the axial displacement to be achieved in a simple manner, thus achieving the aforementioned advantages. This is easy to implement because, for example, a sufficient span length can be selected to ensure axial mobility of the shaft. Thus, torque transmission while providing axial displacement of the shaft can also be achieved in such a way that the device can be retrofitted to the clamping system in a space-saving manner.

[0069] A chain, a rope, a band or, preferably, a belt can be used as the traction element of the traction mechanism.

[0070] Common belt types such as flat belts, V-belts, V-ribbed belts, timing belts, and round belts can be used. Timing belts are preferred because they enable precise power transmission to and drive from the tensioning system.

[0071] The belt can be open, crossed, and / or crossed. An open belt guide is preferred. Therefore, the power transmission structure particularly preferably features an open-guided toothed belt drive. This combines the aforementioned advantages, in particular, precise drive of the tensioning system with optimal use of installation space.

[0072] The preferred traction drive is a slip-capable traction drive, i.e. a traction drive that allows a certain amount of slip. This is the case with flat belts or V-belts, for example. A toothed belt can be designed to be slip-free if it does not transmit power to a wheel in a form-fitting manner, i.e. if it is guided there like a flat belt or V-belt. The use of a slip-capable traction drive provides overload protection, which avoids potential wear and can prevent potential damage to the workpiece and / or tool. If an overload occurs, for example because a defective or incorrectly instructed tool shifts the workpiece (which may be being clamped at the time), the clamping system or device is not destroyed because the traction drive slips instead.

[0073] Furthermore, it has proven advantageous if the device is designed for manual emergency operation. This allows the clamping system to be operated manually even if the device has been retrofitted to the clamping system. For this purpose, for example, a cover is provided that must be removed, after which the spindle can be moved using standard tools. Here, too, the use of a traction drive has proven particularly advantageous because the power transmission structure can be easily separated at the desired location, for example, a belt can be removed or unhooked, allowing an appropriate actuating device, such as a crank, to be attached for manual operation.

[0074] The power transmission structure may further comprise a traction mechanism and a gear train, in particular a gear train, preferably embodied as a planetary gear. This enables optimized adjustment of the transmission ratio and thus optimized utilization of the performance characteristics of the electric drive and, if applicable, the energy storage module.

[0075] However, it has been shown that a power transmission structure that uses a traction mechanism rather than a gear transmission, or preferably no gear train at all, is also applicable. It has been demonstrated that such a power transmission structure can further optimize the installation space, thus allowing for the realization of a compact device.

[0076] Furthermore, the power transmission structure can comprise, for example, bearings, shafts, couplings (detachable or preferably non-detachable couplings).

[0077] A further aspect of the invention relates to system monitoring in order to carry out the clamping process depending on the situation and thus further advance automation. It has proven advantageous for the device to have at least one sensor, in particular a Hall sensor, for detecting a measured variable or a state of the electric drive, and wherein the device is designed, in particular by means of its control stage, to determine a position of a jaw of the clamping system based on the determined measured variable or the determined state. Specifically, the sensor is designed to determine a measured variable on the electric drive, which enables a conclusion to be drawn about a movement state, in particular a rotational speed and / or also a rotor position, and / or an acceleration.

[0078] The measured variable can be used as a control variable for the control stage. The control stage is preferably designed to generate a control variable based on the measured variable.

[0079] As discussed at the beginning, it has proven advantageous for the control stage to be designed to control the electric drive as a function of control variables, as this further automates the clamping process. Preferably, the control stage is designed to control the electric drive as a function of the measured variable detected by the sensor or the state detected by the sensor. This forms the basis for automatic control of the jaw position—for example, the distance between the stationary and movable jaws or the position of the movable jaw—and / or the clamping force, thus leading to a fully automated clamping process.

[0080] As discussed, during the clamping process, the mobile jaw (or similar) is first moved towards the workpiece until the workpiece is contacted at least in two places before the workpiece is subjected to a force and clamped.

[0081] The device is preferably designed to detect, by means of at least one clamping status sensor, whether the clamping system has successfully gripped a workpiece. This allows a differentiation between the travel mode, in which the jaw is moved towards the workpiece and the drive movement of the electric drive is converted into this movement of the jaw, and between a clamping mode in which the workpiece is clamped and in which the drive movement of the electric drive leads to the workpiece being subjected to the clamping force. The electric drive is thus controlled depending on the situation and the clamping process is optimized. In clamping mode, the workpiece is gripped by means of jaws (or similar), whereas in travel mode the jaw(s) are moved towards or away from the workpiece.Preferably, the device is designed to provide the information as to whether the device is in clamping mode to a person operating the machine or to an external entity, in particular the machine itself. This ensures that a clamping force is always present when the workpiece is being machined (for example, by a tool such as a milling cutter). This prevents the unclamped workpiece from being accidentally touched by the tool, thus preventing damage, for example, if a milling cutter grabs the workpiece and ejects it from the clamping system. Detection of the clamping mode thus provides a safety feature.

[0082] Different measuring methods can be used to detect whether the clamping system has successfully gripped the workpiece. For example, a strain gauge (DMS) can be used to record the deformation of components of the device and / or the clamping system, which can be used to determine whether clamping mode has been initiated. A camera can also be provided as a sensor, which detects the clamping system and / or the workpiece, and the device, in particular the camera and / or the control stage, for example using image recognition, determines whether the workpiece has been successfully contacted or gripped. One or more runtime sensors, in particular time-of-flight sensors, can also be used here to record the distance between the jaw and / or the workpiece, so that it can subsequently be determined whether the workpiece has been gripped. A time-of-flight camera (TOF camera for short) can also be used as a sensor for this purpose.Combinations of multiple sensors are also useful for leveraging the advantages of the measurement systems. These sensors each provide one or more measured variables and / or control variables.

[0083] The device preferably has at least one clamping status sensor, in particular an ultrasonic distance sensor, to detect axial movement of the shaft. Because in clamping systems such as the one discussed above, the shaft undergoes an axial displacement when the movable jaw contacts the workpiece, thus initiating the clamping mode, it is easy to determine whether the workpiece has already been gripped by detecting the axial movement of the shaft. The current mode (travel mode or clamping mode) is thus determined. This measure allows for space-saving detection of the system status and permits correspondingly optimized clamping, for example, the precise adjustment of the clamping force.

[0084] By determining which mode is present, i.e. whether the workpiece has been gripped, the distance traveled and / or the clamping force can be determined based on the movements of the electric drive. For this purpose, the device has a means for detecting the movement, in particular the rotation or speed or rpm of the electric drive, in particular of a motor of the electric drive. Such a means can be, for example, a Hall sensor that detects the change in the magnetic field of coils of the electric drive, which can be used to infer a movement of the electric drive or the associated power transmission structure. In travel mode, a relationship exists between the movement of the electric drive and the movement of the movable jaw of the clamping system. This relationship can be described based on the known transmission ratio or empirically, i.e. a test run and the values ​​determined during this test.In clamping mode, the movement of the electric drive is proportional to the clamping force applied by the jaw. This relationship can be determined based on the mechanical conditions and the material properties of the components, or, in particular, empirically. Preferably, the control unit knows these relationships and / or is designed to have these relationships programmed into it. Thus, based on the movement of the electric drive and the clamping status (i.e., which mode is currently active), the control unit can determine the location of the jaw and / or the force with which it is currently clamping.

[0085] The measured values ​​determined can be used to enable optimal semi-automatic clamping. For example, a display unit, such as a screen or a light source, can show the mode the device or system is currently in, the distance already covered, and / or the clamping force already present. On this basis, an operator of the device can precisely control the electric drive and position the jaw in a targeted manner or precisely apply a desired clamping force. Furthermore, the device can be designed to control the electric drive depending on the measured value determined or the status of the clamping status sensor. This means, for example, that a specific position can be reached fully automatically and / or a desired clamping force can be applied. This can be stored, for example, in a memory module.The device can also be designed to save these values ​​after a one-time semi-automatic application of the clamping force and / or position in order to clamp subsequent workpieces according to this specification. This enables precise, reproducible clamping of workpieces, largely eliminating human error.

[0086] The device can also be designed for dynamic adjustment. For this purpose, the device measures the clamping force, as discussed above, and controls the electric drive as needed (via a control stage) to maintain the desired clamping force. This can be done, for example, after the measured clamping force leaves a tolerance range. Because the rigidity of the workpiece changes during machining, this measure prevents damage to the workpiece while simultaneously ensuring that the workpiece is securely held in the clamping system.

[0087] Furthermore, it is advantageous if the device is designed to dynamically adjust the clamping force based on a specification, for example a computer-generated sequence plan. For example, a sequence plan can be generated which changes the clamping force according to a clamping force function over time and / or processing steps. This enables the production of very fragile parts which could otherwise break due to the clamping force, for example when material is removed. This can be controlled, for example, via G-code, in particular using M command sets, to carry out machine functions. G-code, also known as DIN code, is a machine language with which CNC machines can be controlled. These measures therefore make it possible to provide a system for damage-free production or to clamp a clamping system using the device.

[0088] A further aspect of the invention relates to the interconnectivity of the device. It has proven advantageous for the device to have a communication stage, in particular a radio stage, and to be configured for wireless communication, in particular radio-based communication. This enables easy integration into the data processing system of the manufacturing company and / or efficient reading of the data collected by the device and / or simple control of the device.

[0089] It has proven advantageous for the device to have the communication stage, in particular the radio stage, and to be designed for wireless communication, wherein the communication stage is designed to receive and / or transmit control data. Control data can be provided to control external entities or external devices based on the control data generated by the device. For example, a further external clamping device and / or positioning device can be provided which holds and / or positions the workpiece in a further direction, i.e., for example, supports it in one direction. This further clamping device and / or positioning device can thus receive control data which instructs it to additionally fix the workpiece at a second location after the clamping system has successfully gripped the workpiece at a first location.The clamping device and / or positioning device can be designed as a retainer. However, control data can also be provided by external devices to control the device based on the control data. The device is therefore preferably designed to control the electric drive based on the control data.

[0090] The external devices or external entities can be, for example, robots, a computerized numerical control machine (CNC machine for short), a programmable logic controller (PLC for short), a SCADA system (SCADA stands for Supervisory Control and Data Acquisition), a computer, in particular a personal computer, a smartphone, a tablet or similar.

[0091] The control data is typically based on the status of one or more sensors. In this case, the control data can be understood as sensor data.

[0092] Wireless communication can be light-based, such as via infrared, or radio-based. Various standards and wireless technologies can be used, such as Bluetooth, Bluetooth Low Energy, Wi-Fi, ZigBee, etc. Data exchange can also be carried out using OPC UA and / or MQTT and / or TCP / IP and / or IO-Link and / or AMQP.

[0093] As mentioned, the device preferably has at least one region-specific cover made of a non-metallic material, in particular a polymer, which covers the openings in the housing. The radio stage or its antenna configuration is preferably housed behind this housing cover. This enables uninterrupted radio communication while simultaneously providing protection for the device's components.

[0094] The device can thus, for example, be designed to communicate with the machine tool (or another instance in automation networks, such as those controllable via robot control or programmable logic controller (PLC)) in which the clamping system operated by the device is located or which is intended for the clamping system. For example, the machine's workflow plan and / or the current position and / or the planned next machining step can be transmitted to the device. The device is preferably designed to control the electric drive on the basis of this data. The clamping force can thus be adapted to the current or future load on the workpiece. The deformation of the workpiece as a result of machining can thus be influenced. The clamping force can therefore be optimized in relation to the deformation of the workpiece during machining.

[0095] Preferably, the device is designed to be controlled via the control panel of the machine in question, in particular a CNC machine, to which it is connected via the clamping system.

[0096] It has proven advantageous that the communication stage is designed to receive control data, in particular sensor data, from a sensor module external to the device, in particular a sensor module detecting on a jaw of the clamping system. The device thus forms a monitoring system together with a sensor module. The monitoring system for monitoring a clamping system therefore comprises the device according to the invention for retrofitting to the clamping system and the sensor module, in particular a sensor module detecting on a jaw of the clamping system, which is designed to detect a measured variable and / or a state of the clamping system and / or a workpiece clamped therein, wherein the device and the sensor module are designed for wireless communication, in particular for radio-based communication.

[0097] The sensor module is preferably designed to detect the state of the jaw(s) of the clamping system. The sensor module can, for example, comprise a camera, which, as previously described, can be used in the context of the camera of the clamping system, wherein the positioning external to the device enables a particularly advantageous detection range and thus more precise measurement. The sensor module can comprise one or more time-of-flight sensors, in particular time-of-flight sensors, to determine, for example, the distance to a jaw and / or to the workpiece. The sensor module can also comprise a TOF camera. The sensor module preferably comprises a strain gauge (DMS for short) and / or a piezo-resistive sensor, which can particularly preferably be positioned on the jaw. The sensor module can also comprise the jaw, so that the sensor module, together with the jaw, can be attached to the clamping system.This is a jaw that provides sensor data acquisition and can be installed instead of a normal jaw.

[0098] A sensory jaw can therefore be used as an external sensor module, which is discussed below.

[0099] It should be mentioned that in general, i.e. regardless of the use of the device, but especially in combination with the device, it has proven advantageous to design the jaw as a sensory clamping jaw. A jaw used, for example, in a machine vice serves to fix the workpiece inserted between it by applying a normal force. In addition to this normal force, high forces are exerted on the workpiece by the tool used during workpiece machining, which forces are not limited to the direction of the clamping forces. For this reason, the forces generated by the clamping jaws must be correspondingly high to prevent the workpiece from slipping or being thrown away during the process. Forces exerted by the tool that are normal to the applied clamping force pose a particular problem.These are also referred to as transverse forces and are related to the applied clamping force and the existing friction between the clamping jaw and the workpiece. For this reason, when force is applied during workpiece machining, attention must also be paid to the feed rate of the tool so that the applied transverse force does not become too high. It has proven advantageous for the jaw to have a sensor unit designed to detect the transverse force or the transverse force component. As mentioned, the jaw preferably has a sensor unit for detecting the normal force or the normal force component. Particularly preferably, the jaw has a sensor unit for detecting the normal force or the normal force component and a sensor unit for detecting the transverse force or the transverse force component, or a sensor unit for detecting the normal force or the normal force component and the transverse force or the transverse force component.Furthermore, the jaw preferably has a communication connection and / or a communication stage for wired and / or wireless, i.e. wireless, communication with an external entity, in particular the machine and / or the device. The jaw particularly preferably has a communication stage for wireless communication, in particular for radio-based communication. The communication stage is preferably designed as a Bluetooth interface. These measures allow the ratio between the applied clamping force and the forces introduced by the tool to be optimized. This means that the workpiece can be clamped optimally for the respective load occurring, without applying unnecessarily high clamping forces that could damage the workpiece. This measure also allows, for a given clamping force orknown normal force, to instruct the machine to regulate the load on the workpiece in such a way that none of the aforementioned damage occurs, for example because the transverse force does not exceed a maximum value. In both cases, optimized machining is enabled, whereby higher machining speeds and / or more delicate workpiece structures can be achieved. The clamping jaw can be specially manufactured for this purpose. In particular, components or parts of the components of the clamping jaw, for example the communication stage, can be located inside the clamping jaw in a particularly space-saving manner. A commercially available clamping jaw can also be equipped with the corresponding components, so that, for example, the sensor unit and a Bluetooth interface are integrated. The sensors enable the forces applied to the workpiece during the machining process to be measured.

[0100] According to a preferred embodiment of the clamping jaw and the device, the data generated by the sensor unit(s) is transmitted to the device using the communication stage, for example, the Bluetooth interface. The control stage of the device processes the measured data and adapts the process when a process-dependent threshold is reached by adjusting the clamping forces of the clamping jaws applied to the workpiece. At the same time, thanks to the integrated communication interface (or communication stage), the device can intervene in the control of the machine tool in order to adapt the machining process accordingly. In particular, reducing the feed rate of the tool enables a reduction in the forces applied to the workpiece in critical stress cases.

[0101] The sensor-based clamping jaw thus represents a modification of a clamping jaw used, for example, in machine vices, through the integration of sensors and a communication stage, such as a Bluetooth interface. The integrated sensor unit measures the forces occurring during the machining process on the workpiece clamped between the clamping jaws. The sensor data is received and processed by a communication stage integrated into the device. According to a process-dependent, definable threshold value, the device adapts the applied clamping force and the feed rate of the tool to reduce the forces occurring.At least one measured variable and / or control variable is transmitted from the external sensor module (e.g. from the sensory clamping jaw and / or another external sensor module) to the communication module of the device in order to ensure appropriate processing by the device.

[0102] The external sensor module allows for precise adjustment of the clamping force. By combining the measurement methods, the data can be further verified or errors can be detected and diagnosed. For example, during clamping, it may occur that the workpiece or other material does not properly contact the jaws on the designated surfaces, but rather between the designated surface and the housing of the clamping system. This results in a clamping force being applied to the workpiece (or other material), but not across the corresponding surface of the jaw and not at the desired location on the workpiece in the desired direction. The sensor module, which measures the clamping force on the surface of the jaw, thus detects the absence of tension or a tension that is too low compared to the tension determined by the device as previously discussed (for example, using a Hall sensor).This allows the cause of the error to be determined and appropriate warning information to be generated, which can be transmitted wirelessly, displayed on a screen, or indicated by a light signal. Once the cause of the error is identified, it can usually be remedied quickly. This measure thus enables efficient operation of the clamping system and improved maintenance.

[0103] The sensor module can be supplied with power via a wired connection. The sensor module preferably has a sensor module energy storage device for storing and providing electrical energy.

[0104] The sensor module can be connected to the device via a cable for data transmission. Preferably, the sensor module is designed for wireless communication with the device's communication stage, for example, using light (e.g., infrared) or, in particular, radio. Different standards or radio technologies can be used for this purpose, such as Bluetooth, Bluetooth Low Energy, Wi-Fi, ZigBee, etc. Data exchange can also occur, for example, according to OPC UA and / or MQTT and / or TCP / IP and / or IO-Link and / or AMQP.

[0105] The electric drive can now be controlled by the operator of the system or device. It has proven advantageous for the device to be designed to control the electric drive based on the received sensor data and / or control data. This can thus be done completely autonomously. This further automates the entire manufacturing process and enables new manufacturing steps, for example, for very delicate parts that would previously have been impossible.

[0106] It is therefore particularly advantageous that the device has a communication stage, in particular a radio stage, and is designed for wireless communication, in particular for radio-based communication, and that the communication stage is designed to receive control data, in particular sensor data, from an external sensor module, in particular a sensor module detecting on a jaw of the clamping system, and that the device is designed to control the electric drive taking into account the received control data, in particular sensor data.

[0107] Instead of wireless communication, or in addition thereto, the device can be designed for wired communication with the clamping system. The clamping system is accordingly preferably designed for wired communication with the device. This can be done via a cable. However, the device preferably has an electrical contact, in particular a detachable electrical contact, wherein the device is designed to provide information technology and / or power technology contact via the electrical contact when retrofitting to the clamping system. The electrical contact is therefore intended to contact a corresponding electrical contact of the clamping system when the device is joined to the clamping system. Spring contacts, in particular spring contact pins, are preferably used as the electrical contact. Corresponding contact surfaces can be provided on the clamping system.The spring contacts, in particular spring contact pins, can also be provided in the clamping system and corresponding contact surfaces can be provided in the device.

[0108] Thus, the system for clamping a workpiece is preferably designed to exchange data and / or electrical power between the device and the clamping system via a cable, while the system is designed to operate autonomously and without cables from the environment.

[0109] It should be noted that the equivalent mentioned for clamping the workpiece naturally also applies to releasing the workpiece. For example, axial displacement of the shaft detects when the jaws have finished contacting the workpiece, thus ending the clamping mode and starting the travel mode. This means that the movement of the drive unit is no longer interpreted as a change in the clamping force, but rather as a movement of the jaw.

[0110] It should also be noted that multiple mobile jaws and also multiple stationary jaws can be provided in the clamping system. For example, two shafts can be monitored and a mode defined for each shaft. It is also possible to monitor a shaft that only experiences axial displacement once both or several jaws have contacted the corresponding workpiece. The force amplifier is then used. A mode is defined for both jaws, or in the case of multiple jaws, for all of them together, so that the clamping force can be determined from that moment on.

[0111] It should also be mentioned that the device can be designed to measure only the travel or the distance between the jaws, or only the applied clamping force, and to start the measurement only when the corresponding mode (i.e., travel mode or clamping mode) is started based on the movement of the electric drive. Thus, for example, only the revolutions of the electric drive in the corresponding mode are used to determine the respective variable. This is particularly advantageous for applications in which only the travel or the clamping force is relevant and / or in which the other variable is determined by a different sensor. As discussed, one aspect of the invention therefore generally relates to a method for determining the position of a jaw (or similar) of a clamping system and / or a clamping force applied by the clamping system, the method comprising the following steps, namely:

[0112] - Determining the movement, in particular the rotation, of a drive, in particular an electric drive;

[0113] - Detecting whether a force amplifier of the clamping system (or device) has been activated, in particular by detecting an axial displacement of a shaft,

[0114] - Determining a position of the jaw and / or the clamping force based on the determined movement and the detected status of the force amplifier.

[0115] The status describes whether the power amplifier is activated or not, i.e. which mode is currently active.

[0116] This method can also be applied to manual drives, such as cranks, as long as the necessary sensors are available to detect the movement of the drive.

[0117] This method is preferably applied with the electric drive as described. This allows for the execution of a further method step, namely, automated control of the electric drive based on the determined position of the jaw and / or the clamping force, particularly under the influence of an additional control variable.

[0118] In summary, the invention provides an electromechanical retrofit kit for a clamping system, which retrofit kit is configured with respect to its housing structure such that the housing is essentially attached to the head end of the clamping system, where the force transmission between the clamping system and the retrofit kit also takes place, but leaves a mounting plane of the clamping system free, which mounting plane is provided for attaching the clamping system to a machine. The mounting plane forms the lower end of the clamping system.

[0119] Preferably, the height of the housing extends only up to a workpiece placement plane of the system, which is intended for placing a workpiece in the clamping system. The workpiece placement plane is defined by the plane on which the movable jaw of the clamping system can slide or along which the movable jaw can move. The assembly and workpiece placement planes run parallel to each other. The housing is located between them.

[0120] This retrofit kit is preferably operated without external electrical wiring and / or external pneumatic or hydraulic supply.

[0121] Furthermore, it should be mentioned that sensors for detecting the state of the device, the clamping system and / or the environment in the system, in particular in the device, can also be provided. For example, it has proven advantageous for the device (and / or the clamping system) to have a temperature sensor for detecting the temperature or a temperature-dependent state. The device is preferably designed to control the electric drive, in particular to stop the electric drive, depending on the temperature or the temperature-dependent state. In this way, the drive can be reduced or stopped before overheating occurs. The temperature sensor can be designed, for example, as a thermometer or as a temperature switch. The temperature sensor is preferably designed and provided to monitor the electric drive and / or the power transmission structure, i.e., is located accordingly in the device.

[0122] It has also proven advantageous for the electronic display device to be designed to detect the motor current or the current consumption of the electric drive and, in particular, to control the electric drive based on this and / or transmit corresponding information. This allows an assessment of the clamping force based on the electric drive. This can be used, for example, to check whether it corresponds to the clamping force determined by another method (as mentioned above) or whether a fault has occurred in the clamping system, for example, because something is jammed.

[0123] Finally, it should be generally mentioned that the electronic devices discussed (e.g., the control stage, the electric drive, the communication stage, and the external sensor module) comprise electronics. The electronics can be discrete or comprise integrated electronics, or even a combination of both. Microcomputers, microcontrollers, and Application Specific Integrated Circuits (ASICs), possibly in combination with analog or digital electronic peripheral components, can also be used. Many of the device functionalities mentioned are implemented—possibly in conjunction with hardware components—with the aid of software executed on an electronics processor. Devices designed for radio communication usually comprise an antenna configuration for transmitting and receiving radio signals as part of a transceiver module.The electronic devices can also have an internal electrical power supply, which can be implemented, for example, with a replaceable or rechargeable battery. The devices can also be powered wired, either via an external power supply or via "Power over LAN."

[0124] These and other aspects of the invention are apparent from the figures discussed below.

[0125] Short character description

[0126] The invention is explained in more detail below with reference to the accompanying figures using exemplary embodiments, to which, however, the invention is not limited. In the various figures, identical components are provided with identical reference numerals. They show schematically:

[0127] Fig. 1 shows a system comprising a device for clamping a clamping system;

[0128] Fig. 2 an axonometric view of the system;

[0129] Fig. 3 shows another axonometric view of the system;

[0130] Fig. 4A a front view of the device and section line;

[0131] Fig. 4B is a sectional view of the device along the section line in Fig. 4A;

[0132] Fig. 4C is a sectional view of a coupling of the device;

[0133] Fig. 5 the device in the open state;

[0134] Fig. 6 a sectional view of the system;

[0135] Fig. 7 the system in the clamping process in a travel mode;

[0136] Fig. 8 the system in the clamping process in a clamping mode;

[0137] Fig. 9 shows a block diagram of the device. Description of the embodiments

[0138] Figure 1 shows a system 1 for clamping, in particular for clamping, a workpiece 1000 in a clamping system 100. The system 1 has a device 2 for retrofitting the clamping system 100 and the clamping system 100. In the clamping system 100, the workpiece 1000 is clamped between a stationary jaw 102 and a mobile jaw 101. The mobile jaw 102 is screwed to a base housing 103 of the clamping system 100. The base housing 103 accommodates several shafts for moving the mobile jaw 101, wherein a rotational movement of at least one of these shafts is converted by means of a thread into a translational movement of the mobile jaw 101. The system 1 is located in a machine tool, of which a machine table 1002 and a milling machine 1001 are shown as examples. The clamping system 100 is attached to the machine table 1002 by means of slotted nuts (not shown).The device 2 is connected to the clamping system 100 by means of a connecting structure 3 having a connecting surface 3A (see Figure 4B) and a screw connection 3B (screw connection) (see Figure 6). Furthermore, the device 2 has an electric drive 4 (see Figure 4B) that drives a force transmission structure 5 (see Figure 4B), which in turn drives the clamping system 100 and moves or pushes the mobile jaw 101 toward the workpiece 1000 or releases it from it and subsequently moves it away from the workpiece 1000.

[0139] Furthermore, the device 2 has a control stage 6 for controlling the electric drive 4. The control stage 6 (see also Figures 7 and 8) has input elements 6A and 6B (in this case, keys) for entering control commands. To clamp the workpiece 1000, a person operating the system 1 can thus set or select a desired position and / or clamping force via the input elements 6A, 6B, whereupon the electric drive 4 is driven until the mobile jaw 101 has reached the desired position and / or clamping force. Alternatively, the input elements 6A, 6B can be operated to instruct the control stage to drive the electric drive 4. For example, the input element 6B can be pressed until the mobile jaw 101 has reached the desired position or clamping force. After the input element 6B is released, the jaw 101 remains in this position.

[0140] The device 1 has a housing 7 to protect the components contained therein from environmental conditions, in particular from manufacturing waste, such as chips, and possibly coolant. The housing 7 is divided into a base housing 7A and a housing cover 7B, which are screwed together. A metallic housing, in this example an aluminum housing, is used, so that the protective function of the housing 7 is accompanied by optimized heat dissipation. The housing 7 has openings that are closed by covers 8A, 8B, and 8C (see Figure 3). The covers 8A and 8B 8C are made of a polymer or plastic. The plastic covers 8A-8C allow the transmission of radio waves because, unlike the rest of the aluminum housing 7, they do not shield them. Adjacent to the cover 8A, the device 2 has a radio-based communication stage 9 (radio stage).Specifically, this is a WLAN module with an antenna configuration (not shown). This allows the person operating system 1 to transmit control data from a computer, for example, via a WLAN access point (not shown) or directly to communication stage 9. Control stage 6 controls electric drive 4 according to the received control data. Thus, the clamping process can be remotely controlled and also fully automated. Device 2, specifically the control stage, can also be programmed such that the clamping process according to the control data is only started upon confirmation of one of input elements 6A, 6B. This makes it possible to move workpiece 1000 into the desired position before jaws 101, 102 grip it.

[0141] Figure 2 shows a perspective view of system 1. As described in the general part of the description, the clamping system has an axis A around which extend several shafts designed to drive the mobile jaw 101 upon application of a corresponding torque about axis A. Axis A runs parallel to the longitudinal extent of the clamping system 100. The device 2 is designed to apply a torque about this axis A by means of the power transmission structure 5. As can be seen in Figure 6, an axis of a belt pulley 15 of the power transmission structure 5 also runs along this axis A or corresponds to this axis A. The device has a longitudinal extent L that extends normal to axis A. Furthermore, the device has a width B that runs parallel to axis A, i.e., normal to the longitudinal extent L. The longitudinal extent L is longer than the width B.As can be seen in this and the following figures, the device 2 is thus very compact and can be coupled to the clamping system 100 without requiring much space. A height extension H of the device 2 runs normal to the width extension B and the length extension L. The height extension H is less than the height of the clamping system 100 or, more specifically, at most as high as the height of the base housing 103 of the clamping system 100. The height extension H of the device 2 extends in the state installed in the machine tool (as shown in Figure 1) from the upper edge of the machine table 1002 to the upper edge of the base housing 103. The device 2 is therefore designed to couple the clamping system 100 at one end, i.e. to be retrofitted to the clamping system 100 as a retrofit kit, so that the device 2 extends completely below the clamping area in which the workpiece can be clamped between the jaws 101 and 102.

[0142] The device 2, more precisely the housing 7, has two extensions LI and L2, which are located to the left and right of the clamping system 100 and only laterally engage around it, running parallel to the axis A. The two extensions LI and L2 are therefore arranged and designed such that, together with the rest of the housing 7, they engage around the clamping system in a U-shape at its head end, where the force is transmitted. A recess is formed between the extensions LI and L2, which accommodates the clamping system 100. The first extension LI contains the electric drive 4. The second extension L2 contains an energy storage module 10 for storing and providing electrical energy to electrically supply the electric drive 4 and the other electronic components of the device 2. It should be mentioned at this point that the electrical wiring in the device 2 has not been visualized for reasons of clarity.The energy storage module 10 can be charged via a socket 10A using an external energy source, in particular via a power supply connected to the mains. In Figure 2, the socket 10A is located to the right of the two input elements 6A and 6B and has a waterproof cover that can be removed for charging. The position of an electronics unit 6C of the control stage 6 can be seen in Figures 7 and 8. It is located in the lower area of ​​the device 2 and, in addition to a circuit board with passive and / or active electronic components, also has an integrated circuit. The electronics unit 6C is designed to control or regulate the energy supply from the energy storage module 10 to the electric drive 4 in order to implement the moving or exciting function of the device.

[0143] Figure 3 shows System 1 viewed from below. This shows the cover 8C, beneath which the electronics 6C of control stage 6 is located.

[0144] Figure 4A shows the device 2 from the side facing away from the side coupling the clamping system 100. The clamping system 100 is not shown in this figure. Figure 4A shows the section line AA along which the device 2 is shown in a sectional view in Figure 4B.

[0145] This sectional view of device 2 shows the internal structure of device 2. The energy storage module 10, designed as a replaceable battery module, is located in the second extension L2. The second extension L2 has a removable housing part 11, which is secured with four screws positioned around the energy storage module 10 (not visible in the sectional view). In the exemplary embodiment shown here, regular screws are used, which can be removed or tightened using a screwdriver that is usually readily available in a typical application environment. However, manually operable screws can also be used. The use of a lock that can be replaced without additional tools allows for quick and easy replacement of the energy storage module 10.In this exemplary embodiment, the replaceable battery module is electrically coupled to the rest of the device by means of cables and plug connections—not shown, as discussed above. This allows for safe and low-wear replacement of the battery module. Alternatively, spring contacts can be provided for coupling the replaceable battery module to the rest of the device 2, thus enabling particularly quick replacement.

[0146] At the end of the second extension L2 is an emergency stop switch 12, which serves to stop the device 2, in particular to interrupt the power supply from the energy storage module 10 to the electric drive 4. The placement of the emergency switch 12 on one of the extensions L1 or L2 allows for easy accessibility of the emergency switch 12 during operation without impairing the operation of the machine. Furthermore, the placement on the second extension L2 allows for simple and thus error-resistant wiring or installation of the emergency switch 12.

[0147] In summary, the energy storage module 10 supplies the communication stage 9, the control stage 6 and the electric drive 4 with electrical energy.

[0148] Communication stage 9 is located on the left in the illustration at the first projection LI under cover 8A. As mentioned, radio-based communication with other entities outside the device can be carried out at this position using communication stage 9.

[0149] The electric drive 4 positioned within the first extension LI has a brushless direct current motor (BLDC for short), which is controlled by a motor controller via pulse width modulation (PWM). The motor controller is embodied here as part of the electric drive 4, although it should be noted that the motor controller can also be implemented as part of the control stage 6, in particular an electronics unit 6C of the control stage 6. The electric drive 4 has several sensors for determining the state variables of the motor. For example, a Hall sensor detects the motor's magnetic field, and from this the rotational speed is determined. This is transmitted, along with other system-relevant data (as measured variables and / or controlled variables), such as the motor currents, via the UART protocol (where UART stands for Universal Asynchronous Receiver Transmitter), to the control stage 6 and, if necessary, onward to the communication stage 9 and thus to external entities.The Hall sensor is housed in the electric drive 4 and is therefore not visible in the figures.

[0150] Details of the power transmission structure 5 are discussed below. The electric drive 4 drives a first wheel 14 of a belt drive 13 of the power transmission structure 5. A second wheel 15, which is connected to a shaft 17, is driven via a belt 16. The shaft 17 has a first shaft section 17A, on which the second wheel 15 is mounted, and a second shaft section 17B for actuating a power amplifier 105 (see also Figure 6) of the tensioning system 100. The power transmission structure 5 also has a rolling bearing 20 that mounts and radially supports the shaft 17, while simultaneously permitting axial displacements of the shaft 17. A coupling 18 for coupling and driving the tensioning system 100 is located on the shaft 17.

[0151] For the belt guide, reference is made to Figure 5, which shows the device 2 with the housing cover 7B removed (viewing the end face of the second shaft section 17A). The belt 16 is guided from the first wheel 14 via a deflection wheel 23 to the second wheel 15 and from there back to the first wheel 14. Furthermore, Figure 6 shows the screw connection 3B of the connecting structure 3, with which the device 2 is screwed to the tensioning system 100, so that the device 2 can absorb forces and moments from the tensioning system 100.

[0152] Figure 4C shows a sectional view of the coupling 18 (sectioned along the axis of the coupling 18), in which the first shaft section 17A and the second shaft section 17B are visible. The first shaft section 17A is shown here shortened by means of a break line for reasons of space. The coupling 18 has a shaft-like inner coupling part 18E, which is manufactured as part of the shaft 17 and is located between the first shaft section 17A and the second shaft section 17B, and a hollow shaft-like or sleeve-like outer coupling part 18F, which is connected to the inner coupling part 18E via a thread 18G rotating around the axis of the two coupling parts. A rotation of the two coupling parts 18E and 18F relative to one another therefore leads to an axial displacement of the inner coupling part 18E and thus of the shaft 17 relative to the outer coupling part 18F.The outer coupling part has a first bore 18A (see Figure 4B) provided with a thread (not shown) for screwing the outer coupling part to a hollow shaft of the clamping system 100. Furthermore, the outer coupling part has a second bore 18B. Below the second bore 18B there is a spherically rounded coupling element 18C, which is pressed into the second bore 18B by a spring 18D, so that the inner coupling part 18E and the outer coupling part 18F are coupled to each other and rotate together. With a force of approximately 5 kN (a different limit value can be set here as required, for example by selecting the springs 18D and / or the spring travel and / or the geometry of the coupling part 18F and the second bore 18B), the coupling element 18C is pressed against the spring 18D into the inner coupling part 18E and out of the second bore 18B.Once the coupling element 18C has left the second bore 18B, the inner coupling part 18E can rotate relative to the outer coupling part 18F, whereby it migrates from the housing 7 of the device 2, i.e., in the retrofitted state, into the clamping system 100 due to the thread 18G. As shown in Figures 6, 7, and 8, the force amplifier 105 of the clamping system 100 is thus activated. The second shaft section 17B presses on the force amplifier. The axial movement of the inner coupling part 18E and the shaft 17 is monitored by a clamping status sensor, embodied as an ultrasonic sensor 21 (see Figure 4B). The ultrasonic sensor 21 is connected to the control stage 6.If the shaft 17 moves away from the ultrasonic sensor 21, this is detected by the ultrasonic sensor 21 and the control stage 6 recognizes that the limit value of 5 kN has been exceeded and the force amplifier is activated, whereby further driving of the shaft 17 by the electric drive 4 via the force transmission structure 5 no longer leads to a significant movement of the jaw 101, i.e. only a relatively slight movement, but essentially to an increase in the clamping force. A previously existing travel mode has therefore been left and a clamping mode has been initiated, which will be discussed in more detail in the discussion of Figures 7 and 8. The force which is applied by the force amplifier to the coupling 18, in particular to the outer coupling part 18F, during clamping is absorbed by a hardened steel disk 22 and subsequently by the housing 7 and the connecting structure 3.During clamping, a force acts against the device 2 and the connecting structure 3 prevents the device 2 from moving relative to the clamping system 100.

[0153] Figure 6 shows system 1, with device 2 retrofitted to clamping system 100. The cutting direction corresponds to that of Figure 4B and is defined in Figure 4A. The base housing 103 of clamping system 100 is shown in section, and the clamping system 100 has a screw connection 104 that connects the stationary jaw 102 to the base housing 103. The base housing 103 houses a shaft arrangement having a feed spindle 110 designed as a hollow shaft. The feed spindle 110 engages around the force amplifier 105 of the clamping system 100 and the coupling 18 of device 2. The feed spindle

[0154] 110 is screwed to the first bore 18A of the device 2 with the outer coupling part 18F. The feed spindle 110 has an external thread 110A, which winds around the axis A and onto which a spindle nut 111, designed as a hollow shaft, is screwed by means of its thread 111A. The spindle nut 111 is secured against rotation relative to the base housing 103, so that the spindle nut

[0155] 111 can only move along the axis A. The mobile jaw 101 is connected to the spindle nut 111, so that when the spindle nut 101 rotates, it moves with the spindle nut 111 parallel to the axis A.

[0156] The force amplifier 105 has a wedge bolt 106 that extends along the axis A and has a pointed end for pressing apart pressure bodies 107, here designed as pressure rollers, and a blunt end. The blunt end is in contact with the second shaft part 17B of the shaft 17 of the device 2. The second shaft part 17B takes on the function of a pressure spindle. The pressure bodies 107 surround the pointed end of the wedge bolt 106 and their movement is limited in the direction radial to the axis A by the feed spindle 110. In the direction of the axis A, the pressure bodies 107 are limited by the feed spindle 110 and by a support body 109. The support body 109 is designed as an axially movable sleeve and, on the side facing away from the pressure bodies 107, contacts a spring assembly 108 along the axis A, comprising a plurality of disc springs.The spring assembly 108 contacts the outer coupling part 18F on the side facing away from the support body 109 and is supported on it.

[0157] As shown in Figure 7, the system 1, and thus also the device 2, is in the travel mode as long as the mobile jaw 101 does not contact the workpiece 1000. The ultrasonic sensor 21 detects a distance D from the ultrasonic sensor 21 to the second wheel 15 on the shaft 17 and communicates this to the control stage 6. The control stage 6 determines from this that the device 2 is in the travel mode. In the travel mode, the inner coupling part 18E is connected to the outer coupling part 18F via the coupling elements 18C and the second bores 18B. The feed spindle 110 is thus connected to the shaft 17, whereby one rotation of the electric drive 4 (i.e. the motor) causes a movement of the mobile jaw 101 in a specific direction by a defined distance. Because the rotation of the electric drive is detected by means of Hall sensor 4C (see Figure 8), the control stage 6 knows the position of the mobile jaw 101.

[0158] As soon as the mobile jaw 101 contacts the workpiece 1000, this creates a force between the coupling element 18C and the second bore 18B, so that after the force limit (here 5 kN) is exceeded, the coupling element 18C is pushed out of the bore 18B and the inner coupling part 18E can be rotated against the outer coupling part 18F, whereby the rotation involves an axial displacement due to the thread 18G of the coupling 18. The distance D between the ultrasonic sensor 21 and the second wheel 15 increases, so that the control stage 6 knows that the travel mode is being exited and the clamping mode is being initiated.

[0159] As shown in Figure 8, the system 1 and thus the device 2 are now in clamping mode, with each rotation of the electric drive 4 being accompanied by a change in the clamping force on the workpiece 1000. If the shaft 17 is pressed via the thread 18G of the coupling 18 to the wedge bolt 106, these push the pressure bodies 105 apart, which can only deflect radially to a limited extent, so that the pressure bodies 105 press axially against the pull spindle and the support body 109. The support body 109, in turn, presses against the spring assembly 108, which thus provides a defined force. Viewed from the coupling 18, the spring assembly is supported on the outer coupling part 18F and presses the support body against the spread pressure bodies 105, which in turn press on the pull spindle 110, which presses the mobile jaw 101 against the workpiece 1000 via the spindle nut 111.A rotation of the electric drive 4 (in the corresponding direction) thus causes a further displacement or spreading of the pressure bodies 105 and the compression of the spring assembly 108 and thus a defined increase in the clamping force.

[0160] The axial displacement of shaft 17 is detected by ultrasonic sensor 21 and communicated to control stage 6, allowing it to determine when clamping mode is initiated. From this moment, one rotation of electric drive 4 causes a defined change in the clamping force, whereby this value can thus be freely adjusted from the force limit value up to the respective maximum clamping force. The maximum clamping force can, for example, be stored in control stage 6 to prevent damage and ensure sufficient reserves for releasing workpiece 100. Control stage 6 can thus, on the one hand, determine the current clamping force via the rotation of electric drive 4, but can also drive electric drive 4 to set a desired clamping force.

[0161] If one wishes to clamp another workpiece 1000 with the same clamping force as the current one, one can instruct the control stage 6 to store the current clamping force, for example by operating the input elements 6A and 6B and / or by means of an external device that communicates with the device 2, specifically with the control stage 6, via the communication stage 9. The control stage 6 is then instructed to release the workpiece 1000 again, i.e., to detach the jaw 101 from the workpiece 1000 and to return the mobile jaw 101 to its starting position. After the new workpiece 1000 has been positioned in the clamping system 100 against the stationary jaw 102, the control stage 6 can be instructed to apply the stored clamping force, whereupon the control stage 6 controls the electric drive 4 to drive the clamping system 100 as described until the desired clamping force is reached.

[0162] Figure 9 shows a block diagram of an embodiment of the device 2. The device 2 has the energy storage module 10, which has a lithium-ion accumulator 10A and a battery management system 10B. The energy storage module 10 supplies the other electrical components with electrical energy via a line system 25. The line system 25 is divided into a first section 25A, which leads to the emergency stop switch 12, and a second section 25B, which leads from the emergency stop switch 12 to the other components. The emergency stop switch 12 thus disconnects the power supply for all downstream components when it is actuated. The energy storage module 10 provides the power for the control stage 6.

[0163] The control stage 6 has a microprocessor unit 6D for processing, generating, and distributing control data. The microprocessor unit 6D is part of the electronics 6C. The microprocessor unit 6D has a radio stage 6E designed to receive and transmit control data. The radio stage 6E is designed as a WLAN radio stage and has an antenna configuration 6F. Furthermore, the microprocessor unit 6D has an OPC UA server for communicating according to the OPC Unified Architecture standard. OPC stands for Open Platform Communications.

[0164] The control stage 6 further comprises a control unit 6H, which is also designed to process, generate, and distribute control data and is connected to the microprocessor unit 6D via a data line 63. The control unit 6H is also part of the electronics 6C. The control unit 6H is intended in particular for processing sensor data and for generating control data based on the sensor data. The control unit 6H has an RT task processing stage 61. RT tasks stands for real-time tasks. RT tasks refer to the time-critical execution of processes. The use of the RT task processing stage 61 serves to precisely execute the time-critical processes of the control unit 6H with very low latencies. In this way, the processes that include reading in the sensor data and the subsequent generation of control data are executed in real time.The processing stage 61 thus enables the clamping jaws to be controlled directly according to the information received without any time delay.

[0165] The control stage 6 is connected to the electric drive 4, specifically to a motor controller 4A or a motor control stage 4A and the Hall sensor 4C of the electric drive 4, via a data line 26 or a data bus. The motor controller 4A is connected to a motor 4B, specifically a brushless DC motor, also known as a BLDC motor, where BLDC stands for "brushless DC" and DC stands for "direct current." The motor controller 4A is therefore designed as a BLDC motor controller. The motor controller 4A is supplied with electrical power via the line system 25. The motor controller 4A controls the motor 4B and provides the corresponding power via a data and power transmission 4D.The motor 4B is monitored by the Hall sensor 4C, which detects the change in the magnetic field, from which the motor controller 4A calculates the position of the motor 4B (i.e. the angle of rotation of the rotor of the motor 4B) as well as the speed of the motor 4B.

[0166] The motor 4B transmits its mechanical force or mechanical power to the power transmission structure 5. In the block diagram shown here, the power transmission structure 5 has a gear transmission 24, designed as a planetary gear. The belt transmission 13 is connected downstream of the planetary gear. As previously discussed, however, the device 2 can also be designed to directly drive the belt transmission 13. The belt transmission 13 is connected to the shaft 17 and, via this, to the clutch 18.

[0167] The position of the shaft 17 is monitored by the ultrasonic sensor 21, whereby the data of the ultrasonic sensor 21 are transmitted to the control unit 6H via a data line 27.

[0168] The control unit 6H thus receives control data from the microprocessor unit 6D, which is generated on the basis of inputs via the input elements 6A or 6B and / or by data received from external entities, wherein this control data indicates which clamping force, and possibly also which clamping force curve over time and / or work steps, is desired. Furthermore, the control unit 6H receives information via the ultrasonic sensor 21 as to whether the clamping system 100 has already gripped the workpiece 1000, i.e. the status of the device 2, i.e. whether the device is in travel mode or clamping mode. From the electric drive 4, the control unit 6H receives information as to how many revolutions the motor 4B has already completed, in particular how many revolutions the motor 4B has already completed in the respective mode (travel mode or clamping mode).From this, the control unit 6H determines the current position of the mobile jaw 101 and / or the clamping force. Furthermore, the control unit 6H receives information about the motor current that was retrieved via the data line 26, which is used to verify the clamping force or, in the event of deviations between the two measuring methods, to determine any errors during the clamping process. The control unit 6H compares the current clamping force with the desired clamping force and regulates accordingly until the desired clamping force is reached. Via the radio level 6E, the information about the current clamping status, any problems or inconsistencies during clamping, for example due to an incorrectly inserted workpiece 1000, the current position and / or the current clamping force as well as the desired clamping force is transmitted to a user device, for example a tablet of a user of the device 2, where the information is clearly presented on the user device.

[0169] Finally, it should be noted once again that the figures described in detail above are merely exemplary embodiments that can be modified in a variety of ways by those skilled in the art without departing from the scope of the invention. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not exclude the possibility that the relevant features may be present multiple times.

Claims

Claims 1. Device (2) for retrofitting, in particular retrofit kit, for a clamping system (100), in particular for a vice, wherein the device (2) comprises - a connecting structure (3) for connecting the device (2) to the clamping system (100), - an electric drive (4) for providing a mechanical force, - a control stage (6) for controlling the electric drive (4) and - a force transmission structure (5) for transmitting the mechanical force provided by the electric drive (4) to the clamping system (100), wherein the device (2) is designed to transmit the force provided by the electric drive (4) via the force transmission structure (5) to the clamping system (100) for clamping a workpiece (1000) in the clamping system (100).

2. Device (2) according to claim 1, wherein the device (2) has an energy storage module (10), in particular an exchangeable one, for providing the electrical power for the electric drive (4).

3. Device (2) according to one of the preceding claims, wherein the device (2) is designed for reversible connection to the clamping system (100), in particular by means of a screw connection (3B).

4. Device (2) according to one of the preceding claims, wherein the device (2) is designed to support a torque transmitted to the clamping system (100) by means of the force transmission structure (5) via the connecting structure (3).

5. Device (2) according to one of the preceding claims, wherein the force transmission structure (5) is designed to transmit a torque to the clamping system (100) about an axis (A), wherein the device (2) has a width extension (B) extending axially to this axis (A). and a longitudinal extent (L) normal to this axis (A), wherein the longitudinal extent (L) is longer than the width extent (B).

6. Device (2) according to one of the preceding claims, wherein the device (2) has an encompassing shape which is designed to encompass the clamping system (100) in certain areas.

7. Device (2) according to one of the preceding claims, wherein the device (2) has at least one L-shaped extension (LI, L2) or is L-shaped, preferably wherein the device (2) has two L-shaped extensions (LI, L2) or is double-L-shaped or U-shaped 8. Device (2) according to claim 7, wherein the electric drive (4) and / or the energy storage module (10) according to claim 2 is at least partially located in the L-shaped extension (LI, L2).

9. Device (2) according to one of the preceding claims, wherein the force transmission structure (5) is designed to transmit torque to a shaft (17) and to provide axial displacement of the shaft (17).

10. Device (2) according to one of the preceding claims, wherein the power transmission structure (5) comprises a traction mechanism transmission, in particular a belt transmission (13).

11. Device (2) according to one of the preceding claims, wherein the device (2) has at least one sensor, in particular a Hall sensor, for detecting a measured variable or a state of the electric drive (4) and wherein the device (2) is designed to determine a position of a movable jaw (101) of the clamping system (100) on the basis of the determined measured variable or the determined state.

12. Device (2) according to one of the preceding claims, wherein the device (2) is designed to use at least one Clamping status sensor (21) to detect whether the clamping system (100) has successfully gripped a workpiece (1000).

13. Device (2) according to one of the preceding claims, wherein the device (2) has at least one clamping status sensor (21), in particular an ultrasonic sensor (21), in order to detect an axial movement of the shaft (17).

14. Device (2) according to one of the preceding claims, wherein the device (2) has a communication stage (9), in particular a radio stage, and is designed for wireless communication, wherein the communication stage (9) is designed for receiving and / or transmitting control data.

15. System for clamping a workpiece (1000) in a clamping system (100), the system comprising: - a device (2) according to one of claims 1 to 14 and - a clamping system (100), in particular a vice, wherein the device (2) is connected to the clamping system (100) by means of a connecting structure (3).

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