Adaptable gripping device

Abstract

A gripping device has a support (100) and two gripping units (210, 210'). Each gripping unit has a base (211; 211') and two base jaws (212, 213; 212', 213'). The base jaws are capable of moving synchronously in opposite directions relative to their respective bases. The gripping units are arranged side by side on the support such that the base jaws of the two gripping units can move parallel to a common gripping plane. The gripping device is configured as a single gripper by placing first gripping fingers (250, 250') on each of the two outer base jaws (212, 212'). The gripping device can be easily modified into a double gripper by placing two additional gripping fingers on the inner base jaws, or by removing the first gripping fingers and placing second gripping fingers on each of the four base jaws.

Description

Technical Field

[0001] The present invention relates to a clamping device, a machine tool equipped with the clamping device, an application of the clamping device, and a method for operating the clamping device. Background Technology

[0002] So-called double-jaw parallel grippers are known from the prior art. A double-jaw parallel gripper has a base and two gripper jaws. The gripper jaws can move linearly towards and away from each other synchronously at the base. The drive for this reciprocating motion can be, for example, pneumatic or electric. For example, double-jaw parallel grippers of different sizes, as the “GPP5000 series” (pneumatic) and as the “GEP5000 series” (electric), with different reciprocating ranges and different gripping force ranges, are available from Zimmer Group GmbH, DE-77866 Rheinau. The jaws can be preloaded towards the open or closed position by a return spring. Pneumatically driven double-jaw parallel grippers are also known from the product information “UniversalgreiferPGN-Plus-P 380” of Schunk GmbH & Co. KG, DE-74348 Lauffen.

[0003] So-called double-jaw angled clamps are also known from the prior art. In such clamps, the clamp jaws pivot synchronously toward and away from each other about two parallel pivot axes. The Zimmer Group GmbH “GPW5000 series” can be cited as an example. In the following text, both parallel double-jaw clamps and angled double-jaw clamps are generally referred to as double-jaw clamps.

[0004] In the prior art, it has been proposed to mount two separate double-jaw grippers on a common support to form a double gripper. Therefore, DE29500340U1 proposes to mount two double-jaw angled grippers either at an angle to each other or parallel to each other on a common support.

[0005] One important application of fixtures is as manipulators for changing workpieces on machine tools, especially for changing gears on gear machining machines. The manipulator is used to move the workpiece between the workpiece spindle and the workpiece storage area. The workpiece is held in place by the fixtures of the manipulator.

[0006] To minimize machine tool cycle time, operating devices with dual clamping fixtures are sometimes used. One dual-jaw clamp removes the finished workpiece (finished part) from the workpiece spindle, while the other dual-jaw clamp prepares the next blank. The operating device then moves the dual clamps to a position where they transfer the blank to the workpiece spindle. Subsequently, the operating device moves the dual clamps to a position where they place the finished part in the workpiece storage area and receive the next blank. This achieves significant time savings compared to a single clamping fixture.

[0007] Dual-clamp operating equipment is mainly used for small-diameter workpieces, but due to space constraints, it is often unsuitable for larger workpieces. If both small and large workpieces need to be processed on the same machine, then either the advantages of dual clamps must be abandoned, or time-consuming changes or modifications to the entire operating equipment must be made each time. Summary of the Invention

[0008] The purpose of this invention is to provide a clamping device that can be used for workpieces of different sizes, wherein the clamping device can be modified for smaller workpieces, allowing for particularly rapid workpiece changes.

[0009] This objective is achieved by the gripping device according to the invention. Advantageous improvements are given in this invention.

[0010] A gripping device is proposed, comprising a support and two gripping units. Each gripping unit has a base and two base jaws, the base having its own actuator. The base jaws can move synchronously in opposite directions relative to the base via the actuator. The two gripping units are arranged side-by-side on the support such that the base jaws of the two gripping units can move parallel to a common gripping plane. One of the base jaws of each gripping unit forms an inner base jaw, while the other base jaw of each gripping unit forms an outer base jaw. The inner base jaws of the two gripping units are disposed between the outer base jaws. The gripping device is configured as a single gripper in such a way that a first gripping finger is respectively provided on each of the outer base jaws, such that a first object can be accommodated through the first gripping finger, while the inner base jaws do not have gripping fingers for accommodating the object.

[0011] Therefore, two clamping units are arranged side by side on a common support that can be configured as, for example, a pivot arm. This configuration itself is a characteristic of a double clamp. However, the clamping device does not operate as a double clamp, but rather as a single clamp. Here, only the external base jaws of each clamping unit are used, while the internal base jaws do not participate in the clamping process. The distance between the external base jaws of the two clamping units is greater than that between the two base jaws of each individual clamping unit. As a result, the clamping device can accommodate larger objects (especially workpieces) compared to individual clamping units. Because each of the two clamping units has its own actuator and, if necessary, its own return spring, twice the clamping force can be generated compared to individual clamping units. This is particularly advantageous in the case of large objects.

[0012] Preferably, the gripping device has a controller configured as a driver for coupledly operating the two gripping units in a first operating mode, such that the external base claws of the two gripping units move synchronously in opposite directions to accommodate or place an object.

[0013] The gripping device can be easily modified into a dual-gripper configuration by either placing two additional first gripping fingers on the inner base jaw, or by removing the two first gripping fingers from the outer base jaw and placing second gripping fingers on each of the outer and inner base jaws, wherein the second gripping fingers are configured to accommodate other, typically smaller, objects. In this way, a second object can be accommodated independently of the other gripping unit via each of the two gripping units.

[0014] The gripping device, in the sense of a kit, can correspondingly include additional gripping fingers, which are necessary for conversion to dual-grip operation. In particular, the gripping device can include the two additional first gripping fingers mentioned above or the four second gripping fingers mentioned above. They can be mounted on the corresponding base jaws for dual-grip operation, while they are removed from the base jaws in single-grip operation.

[0015] Accordingly, the controller can advantageously switch to a second operating mode for dual-clamp operation, in which the controller operates the two clamp units independently of each other.

[0016] To reliably determine the operating status of the gripping device, each of the gripping units can have a position detection device configured to acquire the position of the target on one of the gripping fingers. Preferably, this is a corresponding external gripping finger, i.e., a gripping finger mounted on a corresponding external base jaw. Thus, not only in single-grip operation but also in dual-grip operation, it is possible to reliably determine the positions of the two external base jaws.

[0017] Position detection devices can, in particular, include inductive position sensors. In this case, the target is preferably made of a soft magnetic material. However, other measurement principles are also conceivable, such as optical distance sensors or eddy current sensors.

[0018] Preferably, the base jaws can move linearly relative to the base of the corresponding clamping unit, i.e., the corresponding clamping unit forms a parallel double-jaw clamp. Alternatively, the base jaws can also pivot relative to the base, i.e., the corresponding clamping unit forms a double-jaw angled clamp.

[0019] The actuator for the base jaw of each gripper unit is particularly capable of pneumatic or electric operation. The base jaw can be mechanically coupled to the actuator, such that the base jaw forces a synchronized reverse movement when the actuator is operated. Each gripper unit can have a return spring to preload the gripper jaw toward the closed or open position of the base jaw in the undriven state.

[0020] The first and second clamping fingers can be configured to accommodate different types of objects. One important type of object is a machine tool workpiece. In a preferred embodiment, the clamping fingers are configured to accommodate toothed workpieces, especially externally toothed gears (spur gears). In this case, the workpiece is accommodated between the clamping fingers in such a way that the two clamping fingers move synchronously toward each other. Each clamping finger has a clamping jaw oriented inward toward the workpiece, which is configured such that the clamping jaw, due to this movement, forcefully holds the workpiece at the outer circumference of the workpiece by an inwardly oriented clamping force. However, it is also conceivable to use a clamping device to accommodate annular, especially internally toothed, workpieces at the inner circumference. For this purpose, the clamping fingers can correspondingly have outwardly oriented clamping jaws or clamping bolts, which are configured such that, due to the reverse movement of the clamping fingers, they forcefully hold the workpiece at the inner circumference of the workpiece by an outwardly oriented clamping force.

[0021] Preferably, the clamping fingers are modularly constructed to allow for particularly rapid and flexible adaptation to different types of workpieces. For this purpose, each of the first and / or second clamping fingers has a base finger and a clamping jaw independently configured therewith. The base finger can be releasably connected to one of the base jaws, particularly at its proximal end. The clamping jaw is releasably connected to the base finger, particularly in the region between the proximal and distal ends of the base finger. In this way, the clamping jaws can be changed very easily and quickly to adapt the device to another workpiece.

[0022] If the corresponding clamping jaw can be connected to the associated base finger via a releasable locking connection, then particularly rapid replacement of the clamping jaw is possible.

[0023] In an advantageous design, the clamping jaw has at least one locking cam. A base finger defines the finger's longitudinal direction. The base finger has an inlet extending laterally into the finger's longitudinal direction, into which at least one locking cam of the clamping jaw can be inserted laterally into the finger's longitudinal direction. A spring-loaded retaining pin is disposed on the base finger, the retaining pin having a locking protrusion. The locking protrusion can be formed, for example, by a transverse pin extending laterally through the retaining pin. At least the locking protrusion extends into the inlet. When the locking cam is inserted into the inlet, the locking protrusion locks into a recess of the locking cam to establish a releasable locking connection. The retaining pin defines a pin longitudinal axis. The retaining pin is movable relative to the base finger along the pin longitudinal axis. The retaining pin extends into an area located outside the base finger. In this area, an operating element is configured at or connected to the retaining pin. The operating element can in particular be configured as a disc or cover, which forms a contact surface for the user's fingers. The releasable locking connection can be released again by the axial pressure acting on the operating element and the resulting movement of the retaining pin along its longitudinal axis. The retaining pin can be surrounded by a helical spring in a region located outside the base finger. This helical spring can be compressed between the outer surface of the base finger and a mating stop disposed on the retaining pin, for example, which can be formed on the operating element, to apply a spring force to the retaining pin toward a position in which the retaining pin secures at least one fastening cam. Preferably, the clamping jaw has two parallel fastening cams, and the retaining pin extends in the inserted state through the region between the fastening cams in the inlet. The retaining pin correspondingly has two locking protrusions that extend transversely to the longitudinal axis of the retaining pin symmetrically with respect to the longitudinal axis of the retaining pin. It is particularly advantageous in this case that the locking protrusions are formed on both sides of the retaining pin by transverse pins that extend transversely through the retaining pin.

[0024] Clamping devices are particularly advantageous for use in gear machining machines for handling toothed workpieces, especially for workpiece changes, i.e., for conveying blanks to and removing finished parts from the gear machining machine. Accordingly, the present invention also relates to a gear machining machine having a clamping device of the above type.

[0025] The present invention also provides a method for operating a gripping device of the above type. In this method, an object is accommodated by a first gripper during single gripping operation, wherein the drivers of the two gripper units are operated in a coupled manner, such that the external base claws of the two gripper units move synchronously in opposite directions.

[0026] The method may also include modifying the gripping device from a single gripper to a dual gripper by: placing two additional first gripper fingers on the inner base jaw, or by: removing the two first gripper fingers from the outer base jaw and placing a second gripper finger at each of the outer base jaw and the inner base jaw.

[0027] After being modified into a dual-clamp system, the method can include: accommodating an object independently of each other through the two clamping units. To this end, the actuators of the two clamping units are manipulated such that the base jaw of each of the two clamping units moves synchronously in opposite directions, independent of the base jaw of the corresponding other clamping unit.

[0028] The method, in both single-clamp and dual-clamp operation, can include: determining the position of one target on each of the clamp fingers located on the external base jaws of the two clamp units. Attached Figure Description

[0029] Preferred embodiments of the present invention are described below with reference to the accompanying drawings, which are for illustrative purposes only and are not intended to be limiting. The drawings show:

[0030] Figure 1 shows an enlarged view of a single fixture unit, which is known in itself;

[0031] Figure 2 A perspective view of a gripping device with two gripping units is shown;

[0032] Figure 3 An exploded view of the gripping device shown in Figure 1 is presented;

[0033] Figure 4 An exploded view of the gripping device in Figure 1 after modification for single-grip operation is shown;

[0034] Figure 5 A three-dimensional view of the base finger pair is shown;

[0035] Figure 6 A top view of one of the base fingers is shown;

[0036] Figure 7 Shown in Figure 6 An enlarged sectional view in plane AA;

[0037] Figure 8 Show Figure 7 The magnified portion of the Z region;

[0038] Figure 9 Showing has Figure 2 A schematic perspective view of a gear-machining machine tool with a clamping device; and

[0039] Figure 10 Show Figure 9 A magnified view of section B in the middle. Detailed Implementation

[0040] Single clamp unit

[0041] Figure 1 shows a clamping unit 210, which is known from the prior art. In this case, the clamping unit is a pneumatically driven two-jaw parallel clamp, as it is commercially available in many different variations. The clamping unit 210 includes a base 211 in which a pneumatic actuator (not shown separately) is housed. The actuator is loaded with compressed air via a hose connector 214. The clamping unit 210 also includes two base jaws 212, 213, which are guided collinearly along the direction of movement V at the base 211. The base jaws 212, 213 can be moved synchronously relative to the base 210 in opposite directions toward or away from each other by the actuator. According to an embodiment, a return spring can be present in the base 210, which applies a closing or opening force to the base jaws 212, 213 in the undriven state.

[0042] As a dual-clamp implementation scheme

[0043] Figure 2 and Figure 3 A gripping device in the form of a clamping arm is shown, wherein each of the clamping units 210, 210' is constructed according to FIG. 1. The clamping units 210, 210' are mounted side by side on a common support 100 in the form of a pivoting arm. The clamping units are constructed substantially identically and are mounted mirror-image of each other with respect to a vertical mirror surface extending centrally between the clamping units 210, 210'. Other components connected to each clamping unit are also mirror-image of components at the other clamping unit.

[0044] exist Figure 2 The clamping unit located on the right side of the diagram, and all components connected to it, are indicated below by unstated reference numerals. Figure 2 The clamping unit on the left and all components connected to it are indicated by the same superscript reference numerals.

[0045] The base jaws 212, 213, 212', and 213' of these two clamping units 210 and 210' can all move collinearly along the direction of movement V in a common clamping plane E. The base jaw 213 or 213' of each clamping unit that is adjacent to the base jaw of the corresponding other clamping unit is referred to hereinafter as the "inner base jaw," and the other two base jaws 212 or 212' are referred to as the "outer base jaws." The inner base jaws 213 or 213' are positioned relative to the direction of movement V between the outer base jaws 212 or 212'.

[0046] exist Figure 2 and Figure 3In one embodiment, the gripping device is configured as a double clamp. For this purpose, clamping fingers 220, 230, 220', and 230' are respectively mounted on each of the base jaws 212, 213, 212', and 213'. The clamping fingers 220 and 230 on the base jaws 212 and 213 of the first clamping unit 210 are configured and arranged such that a gear-shaped workpiece 310 can be accommodated therebetween. To clamp the workpiece 310, the first clamping unit 210 moves the base jaws 212 and 213 synchronously toward each other, preferably under the action of a return force that closes the return spring. Therefore, the workpiece 310 is held between the clamping fingers 220 and 230 by an inwardly oriented clamping force. To release the workpiece 310, the first clamping unit 210 moves the base jaws 212 and 213 synchronously away from each other. Mirror-symmetrical to the clamping fingers 220 and 230 on the first clamping unit 210, the clamping fingers 220' and 230' on the second clamping unit 210' are also configured and arranged to accommodate another workpiece 310' therebetween. To clamp and release the workpiece 310', the second clamping unit 210' moves its base jaws 212' and 213' synchronously toward or away from each other. This is done independently of the operation of the first clamping unit 210. Therefore, in general, two workpieces can be accommodated and placed independently of each other by the clamping device.

[0047] The clamping fingers 220, 230, 220', and 230' are modularly constructed. Therefore, clamping finger 220 includes a base finger 221 and a clamping jaw 222. The base finger 221 has a proximal end and a distal end. At its proximal end, the base finger 221 is releasably mounted on the external base jaw 212 of the first clamping unit 210. For example, mounting can be performed by a screwing part (not shown). To improve positioning accuracy, a positioning sleeve can be provided on the base jaw in a manner known per se. The clamping jaw 222 is laterally mounted on the base finger 221 in the region between the proximal and distal ends of the base finger 221. This connection is also releasable. In this example, the mounting of the clamping jaw 222 on the base finger 221 is performed by a quick-change device, which will be described in detail below. Clamping finger 230 is similar in construction to clamping finger 220, also having a base finger 231 and a clamping jaw 232. The clamping jaws 222 and 232 point toward each other, enabling them to accommodate the workpiece 310 between them. Each clamping jaw contacts the workpiece 310 at at least two points along its circumference to prevent tilting. The clamping fingers 220' and 230' are mirror images of the clamping fingers 220 and 230 in their construction.

[0048] Through its modular construction, it is possible to adapt to different workpieces very quickly and easily, such as gears with different diameters, by simply changing the clamping jaws.

[0049] Each of the clamping units 210, 210' is provided with a position detection device 240, 240' to acquire the operating status of the corresponding clamping unit 210, 210'. The position detection devices 240, 240' determine the position of targets 243, 243', which are located on the corresponding external clamping fingers 220, 220' and near their proximal ends. In this example, the position detection devices respectively include inductive position sensors (displacement sensors) 241, 241'. Accordingly, targets 243, 243' are at least partially made of a soft magnetic material such as steel. To protect the position sensors, each position detection device 240, 240' includes a housing 242, 242', which is mounted on the base 211, 211' of the corresponding clamping unit 210, 210' and covers the corresponding position sensor 241, 241' and the corresponding target 243, 243'.

[0050] Implementation scheme as a single clamp

[0051] exist Figure 4 The diagram illustrates the modification to a single-gripper configuration. To achieve this, the gripping fingers 220, 230, 220', and 230' used for dual-gripper operation are removed from the internal and external base claws 212, 213, 212', and 213'. Instead, two additional gripping fingers 250 and 250' are installed on the external base claws 212 and 212'. The internal base claws 213 and 213' remain empty or are protected by a cover. These internal base claws no longer participate in the gripping process.

[0052] The clamping fingers 250 and 250' are modularly constructed, each having base fingers 251 and 251' and clamping jaws 252 and 252' respectively. The dimensions of the base fingers 251 and 251' and the clamping jaws 252 and 252' are then determined such that a larger workpiece 320 can be accommodated between the clamping fingers 250 and 250'.

[0053] In order to clamp or place the workpiece 320, the drivers of the two clamping units 210, 210' are coupled and operated so that the external base jaws 212, 212' of the two clamping units 210, 210' move synchronously toward or away from each other.

[0054] Because each of the two external base claws 212, 212' belongs to a different clamping unit 210, 210' with its own actuator and, if necessary, its own return spring, this arrangement can achieve twice the clamping force compared to a single clamping unit 210. This is particularly advantageous when dealing with larger workpieces.

[0055] The fixtures 250 and 250' then carry the targets 243 and 243' again, so that the position detection devices 240 and 240' can obtain the operating status of the two fixture units 210 and 210'.

[0056] The opposite approach, from a single clamp to a double clamp, is equally feasible without any problems.

[0057] quick-change device for clamping jaws

[0058] according to Figures 5 to 8 The mounting of the clamping jaw 222 on the associated base finger 221 will be described in detail. The assembly of other clamping jaws on their respective base fingers is carried out in the same manner.

[0059] As in Figure 3 As can be seen, the clamping jaw 222 has two parallel clamping cams 229. The elongated base finger 221 defines the longitudinal direction of the finger with its main extension direction. Especially in Figure 5 and Figure 7As can be seen, a lateral inlet 223 is formed on the base finger 221, transverse to the finger's longitudinal direction. The two fastening cams 229 of the clamping jaws 222 can be inserted into the inlet 223 transversely to the finger's longitudinal direction. A retaining pin 224 is disposed on the base finger 221. The retaining pin 224 defines a pin longitudinal axis. The retaining pin can move along the pin axis transversely to the base finger 221 relative to the finger's longitudinal direction and transversely to the inlet direction of the two fastening cams 229. When the fastening cams 229 are inserted into the inlet 223, the retaining pin extends through the area of ​​the inlet 223 located between the fastening cams 229. A transverse pin 225 extends transversely through the retaining pin 224. The transverse pin 225 forms locking protrusions on both sides of the retaining pin 224, which lock into corresponding recesses on the underside of the fastening cams 229 when the fastening cams 229 are inserted into the inlet 223. A releasable locking connection is established between the clamping jaw 222 and the base finger 221 in this manner. One end of the retaining pin 224 extends into a region outside the base finger 221. In this region, the end is surrounded by a helical spring 227. An operating element in the form of a cover 226 is disposed on the relevant end of the retaining pin 224. The inner end face of the cover 226 forms a mating stop for the helical spring 227. The helical spring 227 is compressible between the outer surface of the base finger 221 and the cover 226 to apply a spring force to the retaining pin 224 toward a position in which the transverse pin 225 secures the fastening cam 229. Here, the surrounding flange 228 on the retaining pin 224 limits the range of movement of the retaining pin 224 in the direction of the spring force and ensures a certain spring preload. The transverse pin 225 is pressed out of the recess of the fastening cam 229 by the axial pressure acting on the cover 226 and the resulting movement of the retaining pin 224 along its pin longitudinal axis. Therefore, the releasable locking connection can be released again. In this respect, cover 226 functions as a button.

[0060] Application in gear machining machine tools

[0061] One important application of the proposed clamping device is workpiece change in gear machining machines. This is in Figure 5 and Figure 6 The exemplary map illustration shows an example of a gear processing machine tool 400. The gear processing machine tool 400 includes, in a manner known per se, a bed 410, a workpiece holder 420, a tool post 430, and a machine controller 440 having a control panel 441.

[0062] The workpiece holder 420 is configured as a rotating turret. The rotating turret carries two workpiece spindles 421, which are offset from each other by 180° relative to the vertical pivot axis of the rotating turret. Figure 5Only one of the workpiece spindles is visible. This workpiece spindle is in the workpiece changing position, in which the finished part can be removed from the workpiece spindle and a new blank can be clamped. Figure 5 In this configuration, another workpiece spindle is obscured by a turret. This other workpiece spindle is in a machining position, in which the previously clamped workpiece can be machined by a tool on the tool holder 430 in a manner known per se.

[0063] In order to replace the workpiece on the workpiece spindle 421 which is in the workpiece changing position, Figure 5 In this example, the aforementioned gripping device is used in a dual-clamp operation. The gripping device, configured as a gripping arm, is secured to a gripping arm seat (not shown). The gripping arm seat is fixedly disposed beside the bed 410, but is not connected to the bed for vibration decoupling. The gripping device is secured to the gripping arm seat such that it can pivot relative to the gripping arm seat about a vertical pivot axis extending parallel to the Z direction via a corresponding actuator and can travel linearly in the Z direction (i.e., along the vertical direction).

[0064] The finished workpiece 310 is located in the workpiece clamping device 422 of the workpiece spindle 421. The associated tailstock 423 with the centering tip 424 retracts upward. The clamping device pivots from its position outside the workspace of the gear machining machine 400 into the workpiece clamping device. Figure 5 and Figure 6 The pivoting position shown in the diagram, and the lowering in the Z direction, allows the first clamping unit 210 and the clamping fingers mounted thereon to receive the finished part 310 from the workpiece spindle. The clamping device removes the finished part 310 from the workpiece clamping device 422 with a short reciprocating motion. Simultaneously, the second clamping unit 210' is ready for the next workpiece (blank) 310' to be processed. The clamping device now pivots further by a small amount, so that the blank 310' stops above the workpiece clamping device 422, and lowers again in the Z direction, so that the blank 310' can be placed on the workpiece clamping device 422. The blank 310' is now clamped on the workpiece clamping device 422. The clamping device is then lifted again in the Z direction and pivots from the workspace toward the workpiece storage 500. The finished part 310 previously held by the clamping unit 210 is placed there, and the new blank is held by the clamping unit 210'. Simultaneously, the blank 310' is further fixed and centered using the centering tip 424, and a centering operation is performed using a centering device (not shown) to obtain the angular position of the teeth of the blank 310' relative to the workpiece spindle axis. Now, the tool holder 420 pivots 180°, so that the workpiece spindle 421 and the blank 310' clamped thereon reach the machining position, while another workpiece spindle and another finished part located thereon reach the workpiece changing position. The blank 310' is now machined by the tool, and the cycle is repeated for the other finished parts.

[0065] Therefore, a workpiece change is performed while another workpiece is being processed. This workpiece change is very rapid, as only a few short reciprocating and pivoting movements are required to remove the finished part from the workpiece spindle and replace it with a new blank. In particular, this eliminates the need for the clamping device to pivot between the workspace of the gear processing machine 400 and the workpiece storage 500. Thus, the entire workpiece change can be performed within the processing time of other blanks, minimizing non-productive downtime.

[0066] However, operating as a dual-clamp system is only feasible for relatively small workpieces. For machining larger workpieces, the clamping device must be modified for single-clamp operation, as described previously. With a single clamp, significantly larger workpieces can now be loaded and unloaded. The maximum diameter of workpieces that can be handled in single-clamp operation can exceed 2.5 times the maximum diameter of workpieces that can be handled in dual-clamp operation. Workpiece changes can always be performed within the process time. However, the clamping device must now pivot completely between the workspace of the gear machining machine 400 and the workpiece storage 500 between removing the finished part and clamping the next blank. This takes more time than the shorter reciprocating and pivoting movements of a dual-clamp system. However, on the other hand, machining larger workpieces generally requires more time, thus allowing for shorter non-production idle times despite a longer overall production cycle time.

[0067] Control and condition monitoring

[0068] All movements of the clamping device relative to the clamping arm seat, as well as the operation of the two clamping units 210, 210', are controlled by a control device simply referred to as a "controller". For this purpose, a separate controller can be provided. Alternatively, this task can also be undertaken by the machine tool's controller 440 or the controller of the workpiece storage 500. The corresponding controllers have corresponding software.

[0069] In particular, the software can distinguish between two operating modes: a first mode in which the gripping device operates as a dual-gripper; and a second mode in which the gripping device operates as a single-gripper. In the first operating mode, the two gripping units open and close independently of each other, while in the second operating mode, the two gripping units open and close simultaneously in a coupled manner.

[0070] Switching between operating modes can be done manually via corresponding input on the control panel. However, it is also conceivable to have an presence sensor on the base jaw of the clamping unit, which determines whether the clamping finger is positioned on the relevant base jaw, and automatically switches between the first and second operating modes based on the signal from the sensor.

[0071] The controller preferably receives position signals from the position detection devices 240 and 240' of the two clamping units. Based on these position signals, the controller is particularly able to distinguish the following states:

[0072] - The associated fixture unit is open;

[0073] - The associated clamping unit is fully closed; and

[0074] - The associated clamping unit is partially closed, and the workpiece is clamped.

[0075] Alternatively, it is feasible to check whether the position of the fixture unit acquired in the "workpiece clamped" state corresponds to the expected position. If the deviation between the acquired position and the expected position exceeds a predetermined tolerance range (e.g., ±1 mm), the controller can infer an error and stop further processing. In this way, it is possible to prevent blanks of incorrect diameter from reaching the workpiece spindle, where they could potentially damage the centering equipment and / or machining tools.

[0076] Modification

[0077] Clearly, numerous modifications can be made without departing from the scope of the invention as defined in the claims.

[0078] For example, compared to the embodiment shown above, the clamping units can have a larger spacing along the movement direction V to accommodate larger workpieces in a single clamping operation. To accommodate different diameters, the clamping units 210, 210' can be movably mounted on the bracket 100 along the movement direction V. For this purpose, the bracket 100 can optionally have corresponding tracks on which the clamping units are movably mounted.

[0079] Alternatively, a parallel two-jaw gripper can be configured, or the gripper unit can be configured as a two-jaw angled gripper. Correspondingly, the base jaws do not travel linearly relative to the base of the respective gripper unit, but rather pivot. Here, all base jaws continue to pivot within the gripper plane E. To avoid collisions, it is preferable in this case that the gripper units are mounted at a slightly larger spacing along the V direction compared to the embodiment shown above.

[0080] Instead of pneumatic drive, the fixture unit can be electrically driven.

[0081] The quick-change device for the gripper jaws can also differ from the configuration shown. In particular, instead of a cover, the operating element can also be configured as a flat disc. Instead of using a transverse pin, the locking protrusion on the retaining pin can also be configured in other ways.

[0082] The clamping device can be used not only for externally toothed gears (spur gears), but also for other types of workpieces, especially those with cylindrical outer contours. By changing the clamping jaws, it is possible to adapt to different workpieces in a very short time.

[0083] Alternatively, a gripping device can be used to accommodate internal toothed gears or other objects on the inner circumference. A gripper for this purpose may, for example, be equipped with downward-projecting pins or downward-projecting and outward-oriented gripper claws. In this case, instead of performing a closing movement, the gripper unit performs an opening movement to accommodate the object. Accordingly, for safety reasons, it is advantageous to use a gripping device in which a return spring generates a restoring force that initiates the opening action.

[0084] In addition to inductive position sensors (displacement sensors), other types of position sensors can also be used to detect operating status, such as optical distance sensors or eddy current sensors.

[0085] List of reference numerals

[0086] 100 brackets

[0087] 210' Fixture Unit

[0088] 211, 211' matrix

[0089] 212, 212' External base claws

[0090] 213, 213' Internal base claw

[0091] 214 Hose Fittings

[0092] 220, 220' External clamps

[0093] 221, 231 base index

[0094] 222, 232 Clamping claws

[0095] 223 Inlet

[0096] 224 Fixed Pin

[0097] 225 lateral pin

[0098] 226 covers

[0099] 227 Coil Spring

[0100] 228 flange

[0101] 229 Fastening Cam

[0102] 230, 230' Internal clamps

[0103] 240 Position Detection System

[0104] 241 Position Detection Device

[0105] 242 Covering device

[0106] 243 Target

[0107] 250, 250' clamps

[0108] 251, 251' base index

[0109] 252, 252' clamping jaws

[0110] 310, 310' workpiece

[0111] 320 workpiece

[0112] 410 Bed

[0113] 420 workpiece holder

[0114] 421 Workpiece spindle

[0115] 422 Workpiece clamping device

[0116] 423 Tail Seat

[0117] 424 Focused Tip

[0118] 430 Tool Holder

[0119] 440 Machine Controller

[0120] 441 Control Panel

[0121] 500 workpiece storage

[0122] E Fixture Plane

Claims

1. A gripping device, comprising: Support (100); and Two clamping units (210, 210'). Each of the clamping units (210, 210') has a base (211; 211') and two base jaws (212, 213; 212', 213'), the base having a actuator, wherein the base jaws (212, 213; 212', 213') are capable of synchronously reversing relative to the base (211, 211') by means of the actuator. Two clamping units (210, 210') are arranged side-by-side on the support (100) such that the base jaws (212, 213; 212', 213') of the two clamping units (210, 210') can move parallel to a common clamping plane (E). One of the base jaws of each clamping unit (210, 210') forms an inner base jaw (213, 213'), and the other base jaw of each clamping unit is an outer base jaw (212; 212'). The inner base jaws (212, 212') of the two clamping units are positioned between the outer base jaws (213, 213') of the two clamping units. Its features are, The gripping device is configured as a single gripper in such a way that a first gripper finger (250, 250') is respectively placed on each of the outer base claws (212, 212') so that a first object (320) can be accommodated by the first gripper finger (250, 250'), while the inner base claws (213, 213') do not have gripper fingers for accommodating the object.

2. The gripping device according to claim 1, further comprising: a controller (440) configured as a driver for coupledly operating the two gripping units (210, 210') in a first operating mode, such that the external base claws (212, 212') of the two gripping units (210, 210') move synchronously in opposite directions.

3. The gripping device according to claim 1 or 2, wherein the gripping device can be modified into a dual gripper by: placing two additional first gripper fingers on the inner base jaws (213, 213'), or by: removing the two first gripper fingers (250, 250') from the outer base jaws (212, 212') and placing second gripper fingers (220, 230, 220', 230') on each of the outer and inner base jaws (212, 213, 212', 213'), such that a second object (310, 310') can be accommodated by each of the two gripper units (210, 210').

4. The clamping device according to claim 3, comprising: Two additional first clamping fingers, the two additional first clamping fingers being configured for placement on the internal base claws (213, 213') of the two clamping units (210, 210'), or Four second clamping fingers (220, 230, 220', 230') are configured to be placed on one of the base claws (212, 213, 212', 213') of each of the two clamping units (210, 210') after the first clamping fingers (250, 250') are removed, such that a second object (310, 310') can be independently accommodated by each of the two clamping units (210, 210').

5. The gripping device according to claim 2, wherein the gripping device can be modified into a dual-gripper device by: placing two additional first gripping fingers on the inner base jaws (213, 213'), or by: removing the two first gripping fingers (250, 250') from the outer base jaws (212, 212') and placing second gripping fingers (220, 230, 220', 230') on each of the outer and inner base jaws (212, 213, 212', 213'), such that each of the two gripping units (210, 210') can respectively accommodate a second object (310, 310'), and The controller is capable of switching to a second operating mode in which the two clamping units (210, 210') are operated independently of each other by the controller.

6. The gripping device according to claim 1 or 2, wherein each of the gripping units (210, 210') includes a position detection device (240, 240') configured to determine the position of the target (243, 243') on the gripping finger (220, 220') disposed on the outer base jaw (212, 212') of the respective gripping unit (210, 210').

7. The gripping device according to claim 6, wherein the position detection device (240, 240') includes an inductive position sensor (241, 241'), and wherein the target (243, 243') comprises a soft magnetic material.

8. The gripping device according to claim 1 or 2, wherein each of the first and / or second grippers (250, 250'; 220, 230, 220', 230') has: Base index (251; 251'; 221; 231), and Clamping jaws (252; 252'; 222; 232). The base finger (251; 251'; 221; 231) can be releasably connected to one of the base claws (212; 213, 212', 213'), and The clamping claws (252; 252'; 222; 232) are releasably connected to the base fingers (251; 251'; 221; 231).

9. The gripping device according to claim 8, wherein the gripper claws (252; 252'; 222; 232) are connectable to the base fingers (251; 251'; 221; 231) via a releasable locking connection.

10. The clamping device according to claim 9, The clamping jaws (252; 252'; 222; 232) have at least one fastening cam (229). The base finger (251; 251'; 221; 231) defines the finger longitudinal direction and has a lateral inlet (223) extending laterally to the finger longitudinal direction, and at least one fastening cam (229) of the clamping jaw (252; 252'; 222; 232) is capable of being inserted laterally into the inlet to the finger longitudinal direction. A spring-loaded retaining pin (224) is provided on the base finger (251; 251'; 221; 231), the retaining pin having a locking protrusion extending into the inlet (223), and The retaining pin (224) is configured and arranged such that when the fastening cam (229) is inserted into the inlet (223), the locking protrusion locks into the recess of the fastening cam (229) to establish a releasable locking connection, and the releasable locking connection can be released by pressure applied to an operating element that is configured on or connected to the retaining pin (224).

11. A gear processing machine tool having a clamping device according to any one of the preceding claims, wherein the first and / or second clamping fingers (250, 250'; 220, 230, 220', 230') are configured to receive a toothed workpiece.

12. An application of a clamping device according to any one of claims 1 to 10 for accommodating a toothed workpiece for workpiece change in a gear processing machine tool (400).

13. A method for operating a gripping device according to any one of claims 1 to 10, the method comprising: The object (320) is accommodated by means of the first clamp finger (250, 250') in such a way that the drivers of the two clamp units (210, 210') are coupled to cause the external base claws (212, 212') of the two clamp units (210, 210') to move synchronously in opposite directions.

14. The method according to claim 13, wherein the method comprises: The gripping device can be modified from a single gripper to a dual gripper by placing two additional first gripper fingers on the inner base jaws (213, 213'), or by removing the two first gripper fingers (250, 250') from the outer base jaws (212, 212') and placing second gripper fingers (220, 230, 220', 230') on each of the outer and inner base jaws (212, 213, 212', 213').

15. The method of claim 14, wherein the method comprises: After being modified into a dual clamp, the drivers of the two clamp units (210, 210') are independently controlled, so that the base jaws (212, 213; 212', 213') of each clamp unit (210, 210') move in opposite directions synchronously with the base jaws of the corresponding other clamp unit without any correlation.

16. The method according to any one of claims 13 to 15, the method comprising: Determine the position of one target (243) on each of the gripper fingers (220, 220') placed on the outer base claws (212, 212') of the two gripper units (210, 210').

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