Rotary heart and clamping device with this rotary heart

Abstract

Rotary heart (10) which serves to clamp a workpiece (90) and includes: - a first plug-in element (11); - a second attachment element (12) which is rotatable relative to the first attachment element (11); and - a plurality of clamping units, each consisting of clamping pieces (15), sliding elements (16) and elastic elements (18, 18a, 18b), wherein the clamping pieces (15) together define a clamping opening (151) directed towards the axial line of the rotating center (10) and are arranged to be rotatably eccentric on the second mounting element (12), wherein the clamping opening (151) can be reduced or enlarged by eccentrically rotating the clamping pieces (15), wherein each clamping piece (15) has an elongated hole (152) extending through the clamping piece (15), wherein the respective sliding element (16) is inserted through the corresponding elongated hole (152) and is arranged on the first mounting element (11) such that the sliding element (16) can be displaced in the elongated hole (152) and cause the clamping piece (15) to rotate eccentrically, wherein the elastic elements (18, 18a, 18b) are each arranged on the clamping pieces (15) and ensure thatthat the clamping pieces (15) clamp the workpiece (90) towards the clamping opening (151) to the same degree of frictional engagement when the clamping opening (151) is reduced by eccentric rotation of the clamping pieces (15), characterized in that the elastic elements (18) are plate-shaped spring discs, each of which is arranged in the elongated holes (152) of the clamping pieces (15), wherein the respective sliding element (16) can be brought to rest against the corresponding plate-shaped spring disc for support, wherein the shear force with which the respective sliding element (16) loads the corresponding clamping piece (15) when moving in the elongated hole (152) is buffered by the corresponding plate-shaped spring disc.

Description

Technical area

[0001] The invention relates to a rotary heart according to the preamble of claim 1 and a clamping device with this rotary heart, in particular a clamping device for grinding a workpiece. State of the art

[0002] A grinding machine is used to machine the outer surface of a workpiece. To machine an elongated workpiece, e.g., a rod-shaped or tubular workpiece, by rotating it, the rotating core is placed over the outer surface of the elongated workpiece so that the centering points press against both ends of the workpiece. By rotating the clamping tool equipped with the rotating cores, the elongated workpiece is rotated and thus ground. CN 206 393 454 U describes a conventional rotating core. Fig. 1 shows that this rotary core comprises a support ring, a first clamping screw, two second clamping screws, a key, and a lock nut. The support ring has three radially arranged threaded holes. The first clamping screw is first screwed into the corresponding threaded hole and then into the lock nut and key, with the lock nut securing the key and the first clamping screw against loosening. Two second clamping screws are screwed together with two further threaded holes. To insert the rotary core, the support ring is placed over a workpiece. By turning the first clamping screw and the two second clamping screws, the clamping width is adjusted to the diameter of the workpiece to be clamped.Once the workpiece is clamped, the key is snapped into a key holder on the workpiece to transmit the torque, while the workpiece is firmly fastened by the two second clamping screws.

[0003] To insert the conventional rotary heart of the type mentioned above, the workpiece must be pushed by humans, and when clamping or releasing the workpiece, the first clamping screw and the two second clamping screws must be turned by humans. The entire clamping process requires a significant amount of time and labor. To automate the sliding of the workpiece over the rotary heart and the clamping of the workpiece with the rotary heart, thereby reducing human labor, a robot arm must be used to insert the workpiece into the rotary heart and further tighten the first clamping screw and the two second clamping screws to clamp the workpiece.If the first clamp screw and the two second clamp screws are tightened to different degrees, or if they clamp a workpiece that is not perfectly round to different degrees, the workpiece may shift and deviate from the predetermined position, resulting in improper machining of the workpiece or a defective product. Furthermore, the first clamp screw and the two second clamp screws extend toward the center of the support ring, making it difficult to align the workpiece when inserting it with the robot arm. As a result, the workpiece is likely to collide with the first clamp screw and the two second clamp screws, resulting in workpiece insertion failure or damage to the rotary hub or the workpiece.

[0004] Patent specification DD 2 67 447 A1 discloses a rotary heart with the features of the preamble of claim 1. Another tensioning device is known from patent application publication DE 10 02 182 A. Object of the invention

[0005] The invention is based on the object of creating a rotary heart and a clamping device with this rotary heart, which rotary heart finds a wider application for workpieces and can also securely clamp a workpiece that is not completely round.

[0006] The invention is based on the further object of creating a rotary heart and a clamping device, which rotary heart and which clamping device are suitable for grinding machines and can automatically clamp or release a workpiece.

[0007] To achieve these objects, the rotary heart according to the invention comprises the features of claim 1. Further embodiments of the rotary heart according to the invention are the subject of the claims dependent on claim 1. The objects are also achieved by a clamping device with such a rotary heart, which comprises the features of claim 7 and, in a further embodiment, the features of claim 8.

[0008] The rotary heart according to the invention comprises a first plug-on element; a second plug-on element that is rotatable relative to the first plug-on element; and a plurality of clamping units, each of which consists of clamping pieces, sliding elements, and elastic elements. The clamping pieces, directed toward the axial line of the rotary heart, together define a clamping opening and are arranged eccentrically and rotatably on the second plug-on element. The clamping opening can be reduced or enlarged by eccentrically rotating the clamping pieces. The respective clamping piece has an elongated hole that extends through the clamping piece. The respective sliding element is inserted through the corresponding elongated hole and is arranged on the first plug-on element in such a way that the sliding element can be displaced in the elongated hole and cause the clamping piece to rotate eccentrically.wherein the elastic elements are arranged on the clamping pieces and provide elastic buffering, under the effect of which the clamping pieces, directed towards the clamping opening, clamp the workpiece to the same extent when the clamping opening is reduced by eccentric rotation of the clamping pieces.

[0009] The rotary heart according to the invention is characterized in that the clamping pieces are caused to rotate eccentrically by rotating the first and second slip-on elements in order to clamp or release a workpiece, thus enabling automated operation of the rotary heart. Furthermore, the elastic elements provide buffering during the clamping process, so that the clamping pieces can also clamp a workpiece that is not completely round with a force fit, thus enabling both automated operation of the rotary heart and a greater tolerable difference between workpieces.

[0010] Short description of the drawings Fig. 1 shows a perspective view of a first preferred embodiment of a rotary heart according to the invention and a clamping device according to the invention. Fig. 2 shows an exploded view of the rotary heart according to the invention and the clamping device according to the invention from Fig. 1. Fig. 3 shows an enlarged view of a clamping piece and an elastic member of the first preferred embodiment. Fig. 4 shows a sectional view of the rotary heart according to the invention from Fig. 1. Fig. 5 shows a first schematic representation of the clamping process of the first preferred embodiment. Fig. 6 shows a second schematic representation of the clamping process of the first preferred embodiment. Fig. 7 shows an exploded view of a second preferred embodiment of the rotary heart according to the invention and the clamping device according to the invention. Fig. 8 shows a first schematic representation of the clamping process of the second preferred embodiment. Fig. 9 shows a second schematic representation of the clamping process of the second preferred embodiment. Fig. 10 shows an exploded view of a third preferred embodiment of the rotary heart according to the invention and the clamping device according to the invention. Fig. 11 shows a first schematic representation of the clamping process of the third preferred embodiment. Fig. 12 shows a second schematic representation of the clamping process of the third preferred embodiment. Detailed description of preferred embodiments

[0011] Objects, features, and advantages of the present invention will be explained in more detail below with reference to the detailed description of exemplary embodiments and the accompanying drawings. However, the invention is not limited to the description of these exemplary embodiments and their illustration in the accompanying drawings.

[0012] In the Fig. 1 to 4, a first preferred embodiment of a clamping device according to the invention is shown, which comprises a rotating heart 10, a housing 20, a lever element 30, detectors 40, 40', bearings 50, a sliding and supporting unit and a drive unit (not shown).

[0013] As in the Fig. 2 to 4, the rotary heart 10 comprises a first slip-on element 11, a second slip-on element 12, three clamping units, a driver 13 and a centering point 14. The first slip-on element 11 has a first axle hole 111, a first end face 112, a second end face 113 and a through-bore 114, wherein the first axle hole 111 extends axially through the first slip-on element 11, wherein the through-bore 114 is located on the outer radial surface of the first slip-on element 11. So that the cooling lubricant remaining in the rotary heart during the grinding process can flow out of the through-bore 114. The driver 13 is firmly mounted on the second end face 113 of the first slip-on element 11 by means of a plurality of screws.The driver 13 is annular and has a driver part 131, a driver recess 132, and a compensating part 133. The driver part 131 and the compensating part 133 are opposite one another and extend radially away from the axial line of the rotary heart 10, the radial length of the driver part 131 being greater than the radial length of the compensating part 133. The driver recess 132 extends axially through the driver part 131, the driver recess 132 being a U-shaped recess that is open radially outwards. The second plug-on element 12 is plugged over the centering tip 14 and comprises a fixing ring 121, a support ring 122, a fastening ring 123, fastening elements 124 and a spacer 125. The support ring 122 is located between the fixing ring 121 and the fastening ring 123. The spacer 125 is hollow-cylindrical in shape.The fastening elements 124 are inserted in turn through the fixing ring 121 and the spacer 125 and further screwed to the support ring 122 so that the spacer 125 is clamped between the fixing ring 121 and the support ring 122, as shown in . Fig. 4. The support ring 122 of the second slip-on element 12 has a slip-on section 1221 and a locking section 1222, with three first locking surfaces 1223 spaced apart and distributed annularly on the outer radial surface of the locking section 1222. The diameter of the first axle hole 111 of the first is larger than the outer diameter of the fixing ring 121 and the outer diameter of the slip-on section 1221 of the support ring 122, so that the first slip-on element 11 can be placed through the first axle hole 111 onto the fixing ring 121 and the slip-on section 1221 of the support ring 122.The fastening ring 123 is removably screwed to the support ring 122, with three second locking surfaces 1231 spaced apart and distributed annularly on the outer radial surface of the fastening ring 123, with each first locking surface 1223 adjacent to a second locking surface 1231, the first locking surface 1223 and the second locking surface 1231, which are adjacent to one another, being located on one and the same plane. This means that three first locking surfaces 1223 and three second locking surfaces 1231 form three locking surface pairs, and each of these locking surface pairs consists of a first locking surface 1223 and a second locking surface 1231, which are adjacent to one another and are located on one and the same plane. Furthermore, a first collar 1225 is arranged on the inner annular surface 1224 of the support ring 122, which protrudes radially in the direction of the axial line of the rotary hub 10.The fastening ring 123 has a second collar 1232 which projects axially in the direction of the support ring 122, the outer diameter of the second collar 1232 being smaller than the diameter of the inner annular surface 1224 of the support ring 122. When the fastening ring 123 is firmly mounted on the support ring 122, the second collar 1232 can be pushed into the support ring 122 and, in the direction of the first collar 1225, can force-fit the bearings 50 such that the bearings 50 are positioned between the second slip-on element 12 and the centering tip 14, such that the second slip-on element 12 is rotatable relative to the centering tip 14 by means of the bearings 50. As shown in FIGS. Fig. 2 and Fig. As shown in Figure 5, each clamping unit comprises clamping pieces 15, sliding elements 16, locking elements 17, and elastic elements 18. Three clamping pieces 15 together define a clamping opening 151 in the direction of the axial line of the rotary heart 10. This opening is a space between the axial line and the three clamping pieces 15, which space serves to clamp a workpiece. The respective locking element 17 is inserted through the clamping piece 15 and screwed to the fixing ring 121 of the second slip-on element 12 such that the clamping piece 15, with the locking element 17 as a support point, is eccentrically rotatable relative to the fixing ring 121.It should be noted that the respective clamping piece 15 has its own center of gravity on the surface of its side facing the clamping opening, wherein the point of the respective locking element 17 inserted through the locking element 15 deviates from the center of gravity of the surface of the side of the clamping piece facing the clamping opening. When the clamping piece 15 is rotated about the locking element 17, the surface of the side of the clamping piece 15 facing the clamping opening 151 rotates eccentrically, wherein the clamping opening 151 is reduced or enlarged during the eccentric rotation of the clamping piece 15 in order to clamp or release a workpiece. The respective clamping piece 15 has an elongated hole 152 which runs axially through the clamping piece 15. The sliding element 16 is inserted through the elongated hole 152 and screwed to the first slip-on element 11. As shown in FIGS. Fig. 3 and Fig. 5, the elastic elements 18 are plate-shaped spring washers, with each elastic element 18 located in the elongated hole 152 of the clamping piece 15. Two notches 1521 are provided on the wall of the elongated hole 152, into which the two ends of the elastic element 18 are inserted. Each elastic element 18 has an opposite top side 181 and a bottom side, with the top side 181 being adapted to bear against the sliding element 16. Between the bottom side of the elastic element 18 and the wall of the elongated hole 152, there is space for the elastic deformation of the elastic element 18. If the sliding element 16 strikes the top side 181 of the elastic element 18, the elastic element 18 will deform elastically and enter the space between the bottom side and the wall of the elongated hole 152.

[0014] As in the Fig. 1 to 5, the housing 20 has a rotary disk 21. Also provided in the housing 20 is a drive unit (not shown), by which the rotary disk 21 can be driven, so that the rotary disk 21 is rotatable relative to the housing 20. The lever element 30 is inserted into the rotary disk 21 and has a shaft 301 which is axially arranged in the driver recess 132 of the driver 13. The detectors 40, 40' are arranged at a distance from one another on the housing 20 such that they are directed against the outer radial surface of the driver 13 in order to detect the driver part 131 of the driver 13. The sliding and supporting unit has a drive element 60 and a push rod 61, wherein the end face of the push rod 61 is directed against the outer radial surface of the second slip-on element 12.By means of the drive element 60, the push rod 61 can be extended telescopically and then supported on the first locking surface 1223 of the support ring 122 and the second locking surface 1231 of the fastening ring 123.

[0015] For the clamping process of the clamping device according to the invention according to the first preferred embodiment, reference is made to the Fig. 4 to 6. First, a workpiece 90 is pushed into the clamping opening 151 of the rotary heart 10 by means of a robot arm (not shown) such that the workpiece 90 is touched and supported by the centering point 14. Advantageously, the inner diameter of the fixing ring 121 of the second slip-on element 12 is larger than the diameter of the workpiece 90 (see Fig. 4) so ​​that the workpiece 90 does not touch the fixing ring 121 during the sliding process. Now the three clamping pieces 15 are in a release state, as shown in Fig. 5. Because the width of the clamping opening 151 is substantially equal to the inner diameter of the fixing ring 121 of the second slip-on element 12, the alignment of the workpiece 90 in the sliding process is facilitated so that the workpiece 90 does not touch the clamping pieces 15. Subsequently, the rotary disk 21 is driven by the drive unit (not shown) such that the rotary disk 21 rotates relative to the housing 20 in the second direction (e.g., clockwise), wherein the centering tip 14 attached to the housing 20 is maintained in a rotationally fixed manner. The rotary disk 21 causes the lever element 30 to move so that the lever element 30 moves in a circle in the second direction with a rotation axis of the rotary disk 21 as the center.Because the lever element 30 is mounted in the driver recess 132 of the driver part 131, the driver 13 is caused to rotate in the second direction when the lever element 30 is moved in a circle. The driver part 131 and the balancing part 133, which are arranged opposite one another, ensure that the center of gravity of the entire driver 13 falls close to the axial line of the rotating heart 10 or falls exactly on the axial line of the rotating heart 10 so that the driver 13 maintains balance during rotation and prevents vibrations caused by inertia. Furthermore, the driver 13 is screwed to the first slip-on element 11 and can therefore cause the first slip-on element 11 to rotate in the second direction. By pulling the clamping pieces 15, the first slip-on element 11 further causes the second slip-on element 12 to rotate in the second direction.Once the driver member 131 has been detected by the detector 40, the turntable 21 stops rotating, causing the lever member 30 and the rotating heart 10 to stop rotating, as shown in FIG. Fig. 5. Now, the first locking surface 1223 of the support ring 122 and the second locking surface 1231 of the fastening ring 123 are directed against the push rod 61. The drive element 60 of the sliding and supporting unit telescopically extends the push rod 61 and then rests on the first and second locking surfaces 1223, 1231. The drive unit then drives the turntable 21 such that the turntable 21 rotates in the first direction (e.g., counterclockwise), causing the driver 13 and the first slip-on element 11 to rotate in the first direction by the lever element 30. Since the first and second locking surfaces 1223, 1231 become rotationally fixed by pressing the push rod 61, the second slip-on element 12 remains rotationally fixed.If the first slip-on element 11 rotates relative to the second slip-on element 12 in the first direction, the first slip-on element 11 causes the sliding elements 16 to slide in the first direction in the elongated holes 152, whereby the three clamping pieces 15 are caused to rotate eccentrically with the locking elements 17 as support points counterclockwise, i.e. in the first direction, wherein the clamping opening 151 is reduced by the eccentric rotation of the three clamping pieces 15 in order to clamp the workpiece 90 in a force-fitting manner. If the driver part 131 has been detected by the detector 40', the rotating heart 10 has clamped the workpiece 90 and the rotating disk 21 stops rotating, whereby the lever element 30 and the rotating heart 10 stop rotating, as shown in . Fig. 6. Now, the three clamping pieces 15 stop rotating eccentrically and are maintained in the state where the workpiece 90 is clamped force-fit by these three clamping pieces 15. Further, the push rod 61 is telescopically retracted by the drive element 60 of the sliding and supporting unit so that the push rod 61 moves away from the first locking surface 1223 and the second locking surface 1231. Then, the drive unit drives the turntable 21 so that the turntable 21 further rotates in the first direction, so that the lever element 30 rotates the rotary heart 10 to rotate in the first direction. Thereby, the rotary heart 10 causes the workpiece 90 to rotate, so that the workpiece 90 is ground.

[0016] It should be noted that a workpiece is manufactured in such a way that the workpiece is not completely round. This means that the radius of the workpiece can vary. The elastic elements 18 of the rotary heart 10 ensure that the three clamping pieces 15 clamp the workpiece 90 in the direction of the clamping opening 151 with the same degree of force. This means that the forces with which the three clamping pieces 15 clamp the workpiece 90 in the direction of the clamping opening 151 are similar. This prevents one or more of these clamping pieces 15 from not touching the workpiece at all or only lightly due to a workpiece that is not absolutely round. Furthermore, the elastic elements 18 ensure that the clamping pieces 15, when a workpiece is clamped by these clamping pieces 15, do not excessively clamp the workpiece due to the height difference of the workpiece surface.This prevents the clamped workpiece 90 from shifting due to the different clamping dimensions of the three clamping pieces 15, deviating from the desired position, and damaging the rotating heart 10 or the workpiece 90. The operation of the rotating heart 10 is explained in detail below. During the clamping process, the first plug-on element 11 causes the sliding elements 16 to slide in the elongated holes 152, whereby the clamping pieces 15 are caused to rotate eccentrically by the displacement of the sliding elements 16. While the sliding elements 16 slide in the elongated holes 152, the sliding elements 16 simultaneously press against the upper sides 181 of the elastic elements 18.With the gradual rotation of the clamping pieces 15 and the force-locking clamping of the workpiece 90 by the clamping pieces 15, the resistance experienced by the sliding elements 16 when sliding the clamping pieces 15 is gradually increased, which leads to the pushing force with which the sliding elements 16 press against the elastic elements 18 when sliding is gradually increased.If the thrust force with which the sliding elements 16 press against the elastic elements 18 is so great that the elastic elements 18 deform under their action, provided that a space exists between the underside of the respective elastic element 18 and the wall of the corresponding elongated hole 152 and is provided for the elastic deformation of the elastic element 18, the elastic elements 18 can be caused to bend and deform towards the underside by the displacement of the sliding elements 16 in order to buffer the thrust force generated by the displacement of the sliding elements 16, so that the sliding elements 16 do not push the clamping pieces 15 further. Otherwise, the clamping pieces 15 would clamp the workpiece 90 so excessively that the rotary heart or the workpiece could be damaged.Even if one of the three clamping pieces 15 rests against the surface of the workpiece segment with a comparatively larger radius, the elastic deformation of the elastic elements 18 can buffer the thrust generated by the displacement of the sliding elements 16 so that the clamping pieces 15 no longer rotate, thus preventing excessive clamping of the workpiece 90 by the clamping pieces 15. The other two clamping pieces 15 can still be caused to rotate by displacement of the sliding elements 16, thus clamping the workpiece 90. Once the workpiece clamping process is complete, all three clamping pieces 15 can effectively clamp and clamp the workpiece 90 toward the clamping opening 151. This means that the three clamping pieces 15 clamp the workpiece 90 to the same extent toward the clamping opening 151.This prevents the workpiece 90 from shifting during the clamping process due to the different clamping dimensions of the three clamping pieces 15 and deviating from the predetermined position. In the worst case, this could even lead to damage to the rotary hub 10 or the workpiece 90.

[0017] Once the driver part 131 has been detected by the detector 40' after the grinding process, the turntable 21 immediately stops rotating, so that the lever element 30 and the rotating heart 10 also stop rotating. Now, the first locking surface 1223 of the support ring 122 and the second locking surface 1231 of the fastening ring 123 are directed against the push rod 61. The drive element 60 of the sliding and supporting unit telescopically extends the push rod 61 and then rests against the first and second locking surfaces 1223, 1231. The drive unit then drives the turntable 21 so that the turntable 21 rotates in the second direction (e.g., clockwise), causing the driver 13 and the first slip-on element 11 to rotate in the second direction via the lever element 30. Since the first and second locking surfaces 1223, 1231 become rotationally fixed by pressing the push rod 61, the second slip-on element 12 remains rotationally fixed.If the first slip-on element 11 rotates relative to the second slip-on element 12 in the second direction, the first slip-on element 11 causes the sliding elements 16 to slide in the second direction in the elongated holes 152, whereby the three clamping pieces 15 are caused to rotate eccentrically in the second direction with the locking elements 17 as support points, wherein the clamping opening 151 is enlarged by the eccentric rotation of the three clamping pieces 15 to release the workpiece 90. Once the driver part 131 has been detected by the detector 40, the rotary heart 10 has released the workpiece and the turntable 21 stops rotating, whereby the lever element 30, the driver 13, and the first slip-on element 11 stop rotating. Now, the three clamping pieces 15 stop rotating eccentrically and are maintained in the release state in which the workpiece 90 is released from the clamping pieces 15.

[0018] In the rotary heart 10 of the clamping device of the first preferred embodiment, it is possible to exchange the spacer 125 of different axial lengths depending on the machining requirements in order to change the axial length of the rotary heart 10. As shown in the Fig. 2 and Fig. As shown in Figure 4, the user can replace the spacer 125 via the through-holes 114 of the first slip-on element 11 as soon as the fastening elements 124 screwed to the support ring 122 are loosened. The fastening elements 124 are then retightened and screwed to the support ring 122. This completes the replacement process, without requiring disassembly of the entire rotating heart 10. In further embodiments of the invention, it is possible to equip the clamping device according to the invention with clamping sets of different dimensions, each clamping set comprising a driver, a first slip-on element, a clamping unit, and a fixing ring.To replace the clamping set, only the fastening elements screwed to the support ring must be removed. The fastening elements, the spacer, the fixing ring, the first slip-on element, the driver and the clamping unit can be removed together in order to replace a clamping set of a different size.

[0019] In the first preferred embodiment, the push rod 61 is designed such that the push rod 61 is telescopically extendable and, in the extended state, is supported on the first locking surface 1223 of the support ring 122 and the second locking surface 1231 of the fastening ring 123. According to the invention, in further embodiments, it is possible for the push rod 61 to be extended and thereby approach the first and second locking surfaces 1223, 1231, but not to be directly supported on these two locking surfaces 1223, 1231. When the lever element 30 causes the driver 13 and the first slip-on element 11 to rotate, it is possible to bring the second slip-on element 12 into a rotationally fixed state, provided that the extended push rod 61 can prevent the rotation of the support ring 122 and the fastening ring 123. Thus, similar effects to those of the first preferred embodiment can be achieved.Furthermore, it is possible that the extended push rod 61 can still prevent the rotation of the second plug-on element 12, even if the push rod 61 is only supported on the first locking surface 1223 or the second locking surface 1231.

[0020] In the first preferred embodiment, the driver recess of the driver is a U-shaped recess that is open radially outwards. This has the advantage that the driver can be removed from the lever element if components need to be replaced. It is also conceivable to design the driver recess as an O-shaped recess. The structural shape of the driver recess is crucial for the driver to be easy to remove from the lever element. Furthermore, it is possible for the driver to have no driver part and no compensating part and to be provided only with a driver recess for the lever element to pass through, whereby in this embodiment the lever element can still cause the driver to rotate.

[0021] In the first preferred embodiment, the lever element is inserted into the turntable. The lever element has a shaft that is inserted axially through the driver recess of the driver. According to the invention, it is also possible to attach the lever element to the driver and arrange a driver recess on the turntable instead of on the driver, so that the shaft of the lever element can be inserted through the driver recess of the turntable. When the turntable rotates, it can still effectively cause the lever element to rotate.

[0022] In the first preferred embodiment, three clamping units are provided, although the number of clamping units is not limited to three and may be any number. Regarding the number of clamping units, it is crucial that the workpiece does not shift during the clamping process and does not deviate from the predetermined position.

[0023] In the Fig. 7 to 9, a second preferred embodiment of the clamping device according to the invention is shown, wherein the second preferred embodiment is essentially the same as the first preferred embodiment of the Fig. 1 to 6 is the same, so that the reference numerals of the first preferred embodiment are still used for the second preferred embodiment. The difference between the first and the second preferred embodiment is that in the second preferred embodiment the elastic elements 18a are designed as tension springs instead of plate-shaped spring washers and the elastic force of the elastic elements 18a is so great that the clamping pieces 15 can be pulled by means of the elastic force and caused to rotate eccentrically in order to clamp the workpiece 90. One end of the elastic element 18a is arranged on an end face 1211 of the fixing ring 121 of the second slip-on element 12, while the other end of the elastic element 18a is arranged on an outer side 153 of the clamping piece 15.In the second preferred embodiment, the respective sliding element 16 is slidably arranged in the elongated hole 152 and causes the clamping piece 15 to rotate eccentrically to such an extent that the elastic element 18a can pull the clamping piece 15. The tensile force of the elastic elements 18a further pulls the clamping pieces 15 so that the clamping pieces 15 rotate eccentrically in the first direction, thereby clamping the workpiece 90 in a force-fitting manner. Thus, the workpiece 90 is clamped and machined in the clamped state.Thus, in the second preferred embodiment, the sliding elements 16 ensure that the clamping pieces 15 clamp the workpiece 90 in a force-fitting manner throughout the clamping process by means of the tensile force of the elastic elements 18a. This prevents the clamping pieces 15 from partially not touching the workpiece 90 at all or from only very lightly touching it, which leads to an uneven force load on the workpiece 90 and thus to a deviation of the workpiece 90 from the predetermined position. In this case, the rotary heart or the workpiece could be damaged. Therefore, the three clamping pieces 15 clamp the workpiece 90 to the same extent in the direction of the clamping opening 151 once the clamping process is completed. This prevents the workpiece 90 from shifting during the clamping process due to different clamping dimensions of the three clamping pieces 15 and deviating from the predetermined position.This also prevents damage to the rotary heart 10 or the workpiece 90.

[0024] In the second preferred embodiment, one end of the elastic element 18a is arranged on the end face 1211 of the fixing ring 121 of the second plug-on element 12, while the other end of the elastic element 18a is arranged on the outer side 153 of the clamping piece 15. However, it is also possible to arrange the other end of the elastic element 18a on the outer radial surface of the clamping piece 15. It is crucial that the respective elastic element 18a is arranged such that the corresponding clamping piece 15 can be pulled by the elastic element 18a and caused to rotate eccentrically, and the clamping opening 151 can be reduced in size.

[0025] In the Fig. 10 and Fig. 12 shows a third preferred embodiment of the clamping device according to the invention, wherein the third preferred embodiment is essentially the same as the second preferred embodiment from the Fig. 7 and Fig.8 is the same. The difference between the third and the second preferred embodiment is that in the second preferred embodiment, the elastic elements 18b are designed as torsion springs instead of tension springs, wherein the clamping pieces 15 are pushed by means of the elastic force and caused to rotate eccentrically in order to clamp the workpiece 90. One end of the respective elastic element 18b is arranged on the end face 1211 of the fixing ring 121 of the second slip-on element, while the other end of the respective elastic element 18b is arranged on the outer side 153 of the respective clamping piece 15. The spiral coil of the elastic element 18b is positioned on the locking element 17.The operating principle of the third preferred embodiment is similar to the operating principle of the second preferred embodiment, the difference being that in the second preferred embodiment, the clamping pieces 15 are pulled by means of tension springs and caused to rotate eccentrically in order to reduce the clamping opening, while in the third preferred embodiment, the clamping pieces 15 are pushed by means of torsion springs and caused to rotate eccentrically in order to reduce the clamping opening.

[0026] The rotary heart according to the invention is characterized in that the three clamping pieces of the rotary heart can rotate eccentrically to clamp a workpiece in a force-fitting manner. Furthermore, the elastic elements of the rotary heart ensure that the force with which each of the clamping pieces clamps the workpiece is similar, so that the clamping pieces do not clamp the workpiece excessively, thus preventing damage to the rotary heart or the workpiece. Even if the workpiece is not perfectly round, the elastic elements of the rotary heart ensure that the workpiece is clamped evenly to prevent the workpiece from shifting during the clamping process and deviating from the predetermined position. This is because a deviation of the workpiece from the predetermined position can lead to faulty machining of the workpiece or a defective product, or even damage to the rotary heart or the workpiece.Furthermore, the width of the clamping opening defined by the three clamping pieces is larger than the diameter of the workpiece and essentially equal to the inner diameter of the fixing ring of the second slip-on element when the clamping pieces are in the state in which the workpiece is released. This facilitates the alignment of the workpiece when pushed into the rotary core, so that the workpiece does not hit the clamping pieces. This prevents the workpiece from being pushed incorrectly and damage to the rotary core or the workpiece itself. Furthermore, the rotary core allows for the spacer of different lengths or dimensions to be exchanged via the through holes in the first slip-on element depending on the machining requirements. It is also possible to exchange clamping sets of different dimensions by dismantling fastening elements.Since replacement is quick and easy, without having to disassemble the entire rotary core, the labor and time required for the replacement process are reduced. Therefore, the clamping and release of a workpiece can be automated with the clamping device according to the invention, which can noticeably reduce labor and time required and correspondingly increase productivity.

[0027] Although the present invention has been described in detail using preferred embodiments, it will be understood by those skilled in the art that the invention is not limited to these embodiments. Rather, modifications are possible such that individual features can be omitted or other combinations of features can be implemented, as long as the scope of the appended claims is not exceeded. The disclosure of the present invention includes all combinations of the individual features presented. List of reference symbols 10 rotating hearts 11 first plug-in element 111 first axle hole 112 first front side 113 second front side 114 Through hole 12 second plug-in element 121 Fixing ring 1211 front side 122 support ring 1221 Attachment section 1222 restricted section 1223 first restricted area 1224 inner ring surface 1225 first covenant 123 Mounting ring 1231 second restricted area 1232 Second Covenant 124 Fastener 125 spacers 13 carriers 131 Driving part 132 Driver recess 133 compensation part 14 Centering tip 15 clamping piece 151 clamp opening 152 slot 1521 incision 153 Outside 16 sliding element 17 Locking element 18 elastic element 18a elastic element 18b elastic element 181 Top 20 housings 21 Turntable 30 lever element 301 shaft 40, 40' detector 50 warehouses 60 drive element 61 Push rod 90 workpiece

Claims

[1] Turning heart (10) used to clamp a workpiece (90) and comprising: - a first plug-on element (11); - a second plug-on element (12) which is rotatable relative to the first plug-on element (11); and - a plurality of clamping units, each of which consists of clamping pieces (15), sliding elements (16) and elastic elements (18, 18a, 18b), wherein the clamping pieces (15) directed towards the axial line of the rotary heart (10) together delimit a clamping opening (151) and are arranged eccentrically rotatably on the second plug-on element (12), wherein the clamping opening (151) can be reduced or enlarged by eccentrically rotating the clamping pieces (15), wherein the respective clamping piece (15) has an elongated hole (152) which extends through the clamping piece (15), wherein the respective sliding element (16) is inserted through the corresponding elongated hole (152) and is arranged on the first plug-on element (11) in such a way that the sliding element (16) can be displaced in the elongated hole (152) and cause the clamping piece (15) to rotate eccentrically, wherein the elastic elements (18, 18a, 18b) are each arranged on the clamping pieces (15) and ensurethat the clamping pieces (15) clamp the workpiece (90) directed towards the clamping opening (151) to the same extent when the clamping opening (151) is reduced by eccentric rotation of the clamping pieces (15), characterized by that the elastic elements (18) are plate-shaped spring washers, which are each arranged in the elongated holes (152) of the clamping pieces (15), wherein the respective sliding element (16) can be brought to bear on the corresponding plate-shaped spring washer, wherein the thrust force with which the respective sliding element (16) loads the corresponding clamping piece (15) when displacing in the elongated hole (152) is buffered by the corresponding plate-shaped spring washer. [2] Rotating heart (10) according to claim 1, characterized byin that the second slip-on element (12) comprises a fixing ring (121), a support ring (122) and a spacer (125), wherein the fixing ring (121) is removably arranged on the support ring (122) and the spacer (125) is removably clamped between the fixing ring (121) and the support ring (122), wherein the clamping pieces (15) are arranged eccentrically rotatably on the fixing ring (121). [3] Rotating heart (10) according to claim 1, characterized by that the rotary heart (10) further comprises a centering tip (14) over which the second plug-on element (12) is plugged. [4] Rotating heart according to claim 1, characterized by that at least one blocking surface (1223, 1231) is further provided on the outer radial surface of the second plug-on element (12), which is arranged distributed on the outer radial surface of the second plug-on element (12). [5] Rotating heart (10) according to one of the preceding claims, characterized bythat the rotary heart (10) further comprises a driver (13) which is fastened to the first plug-on element (11), wherein the driver (13) is switchable by rotation and serves to cause the first plug-on element (11) to rotate when the driver (13) is rotated. [6] Rotating heart (10) according to claim 5, characterized by that a driver part (131) extends radially outwards from the driver (13), wherein the driver part (131) is provided with a driver recess (132). [7] A clamping device which automatically clamps or releases a workpiece (90) and comprises a rotary heart (10) according to any one of claims 1 to 6, the clamping device comprising: - a housing (20) having a rotary disk (21) rotatable relative to the housing (20); - a lever element (30) which is caused to move when the turntable (21) is rotated, so that the lever element (30) moves in a circle with a rotational axis of the turntable (21) as the center, wherein a first plug-on element (11) of the rotary heart (10) is caused to rotate with the rotational axis of the turntable (21) as the center when the lever element (30) is moved in a circle; and - a drive unit which drives the turntable (21) such that the turntable (21) rotates relative to the housing (20). [8] Clamping device according to claim 7, characterized bythat the tensioning device further comprises at least two detectors (40, 40') and a sliding and supporting unit, wherein the at least two detectors (40, 40') are arranged at a distance from one another on the housing (20) and facing the rotating heart (10), wherein the sliding and supporting unit has a drive element (60) and a push rod (61), wherein the drive element (60) causes the push rod (61) to support itself on a second plug-on element (12).

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