DE102015104058B3 - Centric clamping device - Google Patents

Abstract

The invention relates to a clamping device (01) for use on a lathe with at least four clamping base carriers (11) displaceably mounted in a star-shaped manner relative to a rotation axis (04). Here, two clamping base support (11) are pivotally connected to an external rocker (21). These (21) in turn are pivotally mounted on radially displaceable side slides (31). A centric clamping is ensured by a coupling of the outer rockers (21) via a pivotally mounted center rocker (28). To reduce the complexity of the structure is provided that the center rocker (28) with the respective outer rocker (21) by the bearing of an engagement element (22) in a linear guide (23) is coupled.

Description

The invention relates to a clamping device for use in a lathe or the like. For clamping workpieces by means of a plurality of clamping jaws according to the preamble of claim 1.

Chucks for lathes are well known from the prior art in various designs. For clamping of round workpieces a three-jaw chuck is usually used in the prior art in lathes and in the case of square workpieces a so-called four-jaw chuck. In this regard, it requires no further comments. Common to the regular chuck is that the multiple jaws - usually three or four - at the same time manually, hydraulically or electrically adjusted and always have the same distance from the axis of rotation.

The present invention is in particular a clamping device for the centric clamping of workpieces with a shape deviating from an exact roundness, or of rectangular workpieces or round workpieces with form errors. It is obvious that with a regular three- or four-jaw chuck such a chucking task can not be fulfilled.

For this purpose, chucks with four clamping jaws are known from the prior art, in each case two opposing clamping jaws having a common drive and can be adjusted at the same time. The method used here is based on first moving a pair of jaws that are 180 degrees opposite each other towards the workpiece and centering the workpiece on the common axis in relation to the axis of rotation. Subsequently, the offset by 90 degrees pair of jaws on the workpiece is moved and also has the task of accomplishing a centering in the direction of the axis of rotation. After this centering the clamping pressure necessary for turning is applied. This method has proven itself when clamping with clamping jaws, although no exact centering of the workpiece is given to the axis of rotation and the clamping pressure on the four jaws usually slightly different fails. The disadvantage of this solution, however, is that unchanged a centric clamping with uniform clamping pressure on all jaws, especially in case of form errors is not possible.

For this purpose, the document discloses WO 2011/137884 A1 a clamping device with four centrally aligned to the rotation axis clamping base supports, wherein in each case two clamping base support are coupled by means of an external rocker articulated. The two opposite outer rockers are each articulated to a side slide, wherein the two side shifters can be moved toward each other or away from each other by means of a drive. As a result of the storage of the outer rockers and the coupling of the clamping base support is carried out at an adjustment of the side slide on the axis of rotation at the same time an adjustment of all clamping base support also on the axis of rotation. By supporting the outer rocker on the side slide with articulated coupling of the clamping base support, it is possible that when a first clamping base support on the workpiece with continued movement of the side slide accelerates the respectively coupled clamping base carrier to the workpiece. Thus, a clamping of non-circular workpieces is made possible. In addition, it is provided that the two outer rockers are diagonally opposite to the axis of rotation articulated by means of a central rocker coupled together. It is provided that the center rocker is in turn pivotally mounted in the tensioning device, wherein at both ends of the center rocker turn articulated a coupling element is mounted, which in turn realizes the connection to the respective outer rocker. This ensures that opposing clamping base support are moved simultaneously, so that a centric clamping can be ensured.

Although with the present embodiment, both a low tension clamping of non-circular workpieces as well as a centric clamping is possible, but it requires a plurality of hingedly interconnected components. This leads to not negligible costs in the realization of corresponding clamping devices.

Object of the present invention is therefore to simplify the known embodiment.

The object is achieved with a device according to the invention according to claim 1.

Advantageous embodiments are the subject of the dependent claims.

A generic clamping device is for use on a lathe, in particular a face plate. The use is not limited to a regular lathe, but is also given for other machine tools. In this respect, an unrestricted use for clamping a workpiece on, for example, a machining center is given. The use is particularly suitable when it comes to enable a centric and deformation-free clamping of workpieces.

In the present case, the generic clamping device has at least four star-shaped to a rotational axis in a device carrier carrier guides. In a non-rotating clamping device - or in use at a machining center - corresponds to the center axis of the axis of rotation considered below. In the carrier guides in each case a clamping base support on which at least one clamping jaw can be attached for clamping workpieces, slidably mounted in a support direction. In this respect, the support direction is in each case radial to the axis of rotation. By means of an actuator of the clamping device, the clamping base support can be adjusted simultaneously in the respective beam directions.

Furthermore, it is provided that in each case two clamping base carriers are coupled directly or indirectly to one another by means of an external rocker, wherein the external rocker can be displaced linearly by means of an actuator in a thrust direction extending radially to the axis of rotation. As a result of the coupling of two clamping base carriers on the outer rocker, a displacement of the outer rocker in the thrust direction simultaneously leads to a displacement of the clamping base carrier in the respective carrier directions. In this case, it is provided that the outer rocker is pivotally connected about a pivot axis aligned parallel to the axis of rotation pivotally displaceable with a side slide. For this purpose, the side slider is mounted in the device carrier such that by means of the actuator of the side slider can be moved in the thrust direction and is fixed transversely to the thrust direction, d. H. The sideshift can only be moved in one direction in the direction of thrust. The storage can take place via the actuator and / or alternatively by means of guides in the device carrier.

To realize a low-stress centric clamping of non-circular workpieces, it is necessary that at least in the middle of the travel of the clamping base support a limited displacement of a clamping base carrier inwardly leads to a pivoting of the outer rocker and a displacement of the coupled clamping base carrier to the outside. Which type is the connection between the clamping base beams and the outer rocker, is initially arbitrary. It should be noted in principle that it comes at a displacement of a clamping base support in the radial direction at the same time via the coupling by means of the outer rocker to an opposite displacement of the other clamping base support.

Furthermore, a pivotally mounted center rocker is arranged on the device carrier, which is pivotally coupled to at least two outer rockers. In the case of more than three outer rockers, at least two outer rockers are to be coupled diagonally across the axis of rotation. The center rocker is supported in a particularly advantageous manner in a bearing which coincides with the axis of rotation.

By the coupling is achieved that each opposite clamping base support are moved simultaneously to the axis of rotation. Thus, the centering movement of the clamping device according to the invention is significantly improved. Nevertheless, the advantageous compensation movement between two clamping base beams is still given via the outer rocker. Thus, for example, four clamping base beams, the opposite clamping base support always the same distance from the axis of rotation. An off-center clamping of a workpiece, which can not otherwise be excluded, is advantageously prevented by this embodiment.

In contrast to the prior art, the invention provides that the coupling of the central rocker and the outer rocker is effected by the use of a linear guide and an engagement element mounted displaceably therein. Provided here is that when moving the outer rocker on the axis of rotation to or from the axis of rotation away, an adjustment of the engagement member along the linear guide takes place. Furthermore, it is necessary that the engagement element has a parallel to the axis of rotation extending engagement axis about which a pivoting movement of the outer rocker can take place relative to the center rocker.

To realize the embodiment of the invention, depending on the assignment of the linear guide and the engagement element, two alternative embodiments are available.

In a first embodiment according to the invention, the outer rockers each have a linear guide running perpendicular to the axis of rotation, along which the engagement element is displaceable. In this respect, the engagement element remains in a displacement of the outer rockers at a constant distance from the axis of rotation. For coupling of central rocker and outer rocker, it is necessary in this embodiment that the center rocker is pivotally mounted about the engagement axis. Pivoting the outer rocker leads directly to a pivoting of the linear guide. As a result, the mounted in the linear guide engagement element is moved with its engagement axis. Due to the storage of the center rocker about the engagement axis, the center rocker is also pivoted. This in turn leads to an analogous panning in the other outdoor rocker.

In a second embodiment of the invention, the linear guide of the center rocker and on the other hand associated with the engagement element of the outer rocker. Here, the center rocker on at least two perpendicular to the axis of rotation extending linear guides, along each of which an engaging element is displaceable. In this respect, the linear guide is stationary aligned with the axis of rotation. Here, the engagement element has a parallel to the axis of rotation extending engagement axis about which the respective outer rocker is pivotally mounted in this embodiment. Analogous to the previous embodiment, the adjustment of the outer rocker leads to the axis of rotation to or from the axis of rotation away to an adjustment of the engagement member along the linear guide.

If, however, the outer rocker is pivoted, this leads to an adjustment of the engagement axis and thus of the engagement element, as a result of which the linear guide and thus the center rocker are likewise pivoted in its bearing. This leads analogously to the previous embodiment directly to a corresponding pivoting of the respective other outer rocker.

By the removal of the coupling element between the center rocker and the outer rocker, a simplification of the structure is achieved, which is both in terms of cost of advantage, as well as the reliability of the chuck positively influenced. Through the engagement of an engagement element in a linear guide and its pivotability about the engagement axis, a reliable coupling of the two outer rockers is achieved, without the need for the pivotally mounted coupling element on both sides.

With regard to the alignment of the linear guides in relation to the axis of rotation, it is advantageous if the linear guides extend radially. If the arrangement of the linear guide takes place on the center rocker, then a radial alignment of the linear guide is independent of the position of the center rocker provided that the center rocker is pivotably mounted about the axis of rotation in a particularly advantageous manner. If the arrangement of the linear guides on the outer rocker in association with the engagement elements on the center rocker, so it is obvious that the linear guides can not run independently of the position of the outer rocker radially. In this case, it is rather advantageous if the linear guides extend radially in a middle position of the respective outer rockers.

In addition, it is particularly advantageous if the linear guides are aligned in accordance with the thrust direction. This ensures that when adjusting the outer rocker by the drive of the side shifters, an adjustment of the engagement elements along the linear guides takes place without causing an additional pivotal movement between the center rocker and the outside rocker.

With regard to the arrangement of the engagement elements on the center rocker or in an alternative embodiment on the outer rocker are also various options available. In a particularly advantageous first variant, the engagement elements are fixedly arranged on the central rocker (first embodiment according to the invention with the linear guide on the outer rocker) or fixed on the outer rocker (second embodiment according to the invention with the linear guide on the center rocker). It can be provided both that the central rocker and the outer rockers integrally comprise the engagement elements, as well as alternatively the engagement elements can be attached to the center rocker or fixed to the outer rocker.

Due to the pivoting of the central rocker about the engagement axis of the engagement element or the pivoting of the outer rocker about the engagement axis of the engagement element, it is accordingly required in this variant that the engagement elements at least partially have a rotational shape about the engagement axis. An advantageous system in the linear guide is achieved, for example, by a cylinder aligned along the engagement axis.

In contrast, it is also advantageously possible in a second variant to use separate engagement elements, which are pivotally mounted about the respective engagement axis. In the arrangement of the engagement elements on the central rocker so far is a pivotable mounting of the engagement elements on the center rocker, wherein the engagement elements along the respective linear guide of the outer rocker are linearly displaceable. Similarly, in the arrangement of the engagement elements on the outer rocker pivotable about the engagement axis bearing on the respective outer rocker, wherein also the linear displaceability of the engagement elements along the linear guide of the center rocker is required.

With regard to the arrangement of the clamping jaws relative to the clamping base support, there are various possibilities. In this regard, the execution in the WO 2011/137884 A1 to get expelled.

At least it is advantageous if a parallel to the carrier guide jaw guide is present on the respective clamping base support. It is provided that on the jaw guide the clamping jaw is also displaceable radially to the axis of rotation and fixable. In any case, it is advantageous if at the jaw guide - regardless of which variant - a locking toothing is present, wherein at least one clamping jaw along the The jaw guide can be moved and fixed in the latching interval.

In a particularly advantageous embodiment, at least twice an arrangement with an external rocker and two clamping base beams is present. This means that always two clamping base support are coupled to an external rocker and form an array. It is not provided that the two already coupled via an external rocker clamping base carrier are additionally coupled to the other respectively adjacent clamping base carriers. In this respect, there is always a double number of clamping base beams in relation to the number of outer rockers. In this embodiment, it is therefore assumed in the simplest case of a double arrangement with two outer rockers and four clamping base beams. Likewise, this arrangement can be extended by a plurality and in particular thus also include an arrangement of three outer rockers and six clamping base beams or four outer rockers and eight clamping base beams.

This ensures advantageously a symmetrical design of the outer rocker and the connection to the clamping base carriers a uniform movement and a uniform force distribution.

It is obvious that it is necessary for the functional design of an arrangement of external rocker and two clamping base beams to allow a balance between the outer rocker in its pivotal movement and the clamping base beams in their adjusting movements. As a result of the clamping base carrier which can be adjusted radially in the carrier directions radially relative to the axis of rotation, the distance of the two coupled clamping base carriers from one another changes accordingly. In this respect, it requires the coupling by means of the outer rocker compensation of this changing distance between two clamping base beams. Furthermore, the opposite displaceability of two clamping base carrier in the carrier directions requires a compensation possibility in the connection to the outer rocker.

Here, on the one hand, the possibility is open, for example, at the end of the outer rocker to provide ball joints, which engage in holes in the clamping base carriers and in this case are displaced tangentially to the axis of rotation. A disadvantage of this solution, however, is that there is a friction of the ball joint in the bore in the outer rocker due to a pushing movement in the bore. Thus, a functional capability over a long period is not guaranteed beyond doubt.

Furthermore, it is possible to arrange in each case a compensation element between the outer rocker and the two coupled clamping base carriers. This requires a mutually pivotable mounting between the compensating element and the outer rocker or the clamping base support. Thus, in a simple manner, a displacement of a clamping base support via an adjustment of the compensating element to a pivoting of the outer rocker and an opposite adjustment of the other compensating element and thus the opposite displacement of the other clamping base support lead.

However, it is advantageous if, for the transmission of the movement of the outer rocker on the respective clamping base support along a transverse guide slidable sliding body is used. The sliding body in this case has a coupling axis extending parallel to the axis of rotation, wherein the outer rocker is pivotable relative to the clamping base carrier about this coupling axis.

Here are in turn two alternative connection variants depending on the assignment of the transverse guide and the slider to the outer rocker or to the clamping base support available.

In a first particularly advantageous connection variant, the clamping base carriers each have a transverse guide running perpendicular to the axis of rotation. It is particularly advantageous here to align the transverse guide tangentially to the axis of rotation. To this coupling axis each associated outer rocker is pivotally mounted. In an adjustment of the outer rocker, for example, to the pivot axis, the associated displacement of the coupling axis parallel to the thrust direction simultaneously leads to an adjustment of the slider in the thrust direction. As a result of its mounting in the transverse guide, the clamping base carrier is moved immediately in the pushing direction, wherein a movement of the sliding body along the transverse guide also occurs due to the mounting of the clamping base carrier in the radial carrier direction. The pivoting of the outer rocker about the coupling axis of the slider allows the other hand, the pivoting of the outer rocker, so that the desired balance between the clamping base beams can be done.

In a second alternative connection variant, the outer rocker has two transverse guides each (one outer rocker each) perpendicular to the axis of rotation. According to the pivotability of the outer rocker, it is obvious that these transverse guides can not be aligned tangentially to the axis of rotation regardless of the position of the outer rocker. Rather, it is provided that advantageously extend the transverse guides in a central position of the outer rocker tangent to the axis of rotation. Analogous to the previous embodiment, a sliding body is provided, which is displaceable along the transverse guide and in this case has a coupling axis extending parallel to the axis of rotation. Around this coupling axis is the respectively associated clamping base support pivotally mounted. Analogous to the previous connection variant, a displacement of the outer rocker and thus of the transverse guides in the thrust direction likewise leads directly to a displacement of the sliding bodies in the thrust direction. Due to the mounting of the clamping base carrier in the coupling axis of the slider this is also displaced, wherein the displacement takes place along the carrier direction. This in turn leads to a displacement of the slider in the carrier direction and at the same time along the transverse guide.

The assignment of the slider on the outer rocker or on the respective clamping base support can also be done in various ways. On the one hand, it is possible to assign the slider integral or fixed the external rocker. It is obvious that the slider is realized as an aligned in the direction of the coupling axis cylinder bolt in an advantageous manner. This can thus be moved both along the transverse guide, as well as to be pivoted about the coupling axis. When assigning the slider to the clamping base support, it is also possible to arrange them there integrally or fixed.

However, it is particularly advantageous in particular for reducing the surface pressure and thus increasing the service life if the sliding body is mounted pivotably about the respective coupling axis on the outer rocker or on the respective clamping base support. In this respect, the slider is a separate component which is linearly displaceable on the one hand along the transverse guide and on the other hand is pivotable about the coupling axis relative to the outer rocker or relative to the base jaw.

The connection between the separate sliding body and the outer rocker or the clamping base support can also be done in various ways. It is possible to provide the slider with a aligned in the direction of the coupling axis bearing pin which is pivotally mounted in a bearing sleeve of the outer rocker and the clamping base support. In contrast, the slider can be designed for storage in the transverse guide, for example, as a cuboid. Alternatively, the sliding body forms a bearing sleeve in which a aligned in the direction of the coupling axis bearing pin is pivotally mounted. Here, the bearing pin of the outer rocker or the clamping base support is assigned.

Because of the initially free displaceability of a clamping base carrier relative to the coupled clamping base carrier, it is advantageous if at least one position is provided in which this displaceability of the clamping base carrier is prevented. In this regard, the execution in the WO 2011/137884 A1 to get expelled.

It is particularly advantageous if the two clamping base carriers coupled to the outer rocker, or thus their two carrier directions, are arranged symmetrically with respect to a plane consisting of the direction of thrust and the axis of rotation. Thus, it is ensured that it comes first with mental neglect of the pivoting of the outer rocker or the opposite displaceability of the clamping base support to a uniform movement mounted jaws to the axis of rotation or away from the axis of rotation.

For the implementation of the actuator are various options open, being used in a particularly advantageous manner as an actuator arranged in the direction of thrust adjusting spindle. Here, the adjusting spindle is mounted in a first side slide with a left-hand thread and a second opposite side slide with a right-hand thread. Consequently, a rotational movement of the adjusting spindle leads to an opposite movement of the side shifter towards or away from each other. It is obvious that thus with the movement of the adjusting spindle and the opposite movement of the side shift at the same time the outer rockers are moved and thus takes place a movement of the clamping base or the clamping jaws towards each other or away from each other.

Although it is not absolutely necessary, this advantageously the adjusting spindle is rotatably mounted and fixed in the thrust direction in the device carrier. It is particularly advantageous in this case if the positioning of the adjusting spindle in the axial direction is centered on the axis of rotation, wherein via adjusting means, such as adjusting nuts, an axial adjustment of the position of the adjusting spindle can be made. This ensures that the sideshift have the same distance from the axis of rotation on both sides. It is obvious that, for example, for attaching a drive to the adjusting spindle or for supporting the adjusting spindle, the side shifters need not necessarily be designed to be symmetrical. In this respect, the same distance to the axis of rotation refers to the functional assignment in conjunction with the two respective outer rockers.

The positioning of the adjusting spindle is initially arbitrary. However, it is particularly advantageous if the axis is perpendicular to the axis of rotation. Thus, first of all a symmetrical construction of the side shift is made possible. Furthermore, it is particularly advantageous if the axis of the adjusting spindle cuts the axis of rotation. This ensures that the force acting on the sideshift as tensile or compressive force and the shear forces are minimized. Thus, it may be possible to dispense with a guide for the side slide in the device carrier.

As an alternative solution, it is possible to couple two side shifters via a wedge guide with a wedge element. In this case, an adjusting movement of the wedge element in an adjusting direction by means of the actuator leads to an opposite movement of the side slide. Consequently, the clamping task is also solved in that the adjustment of a wedge element by means of the actuator leads to a movement of the clamping jaws on the axis of rotation to or from the axis of rotation away. To implement it requires acute-angled wedge guides aligned with each other. The person skilled in the art will choose the angle on the basis of the necessary travel ranges of the sideshift and the required actuating force, with a small angle leading to a small travel and to high actuating forces.

In the arrangement, furthermore, the adjusting direction is expediently aligned perpendicular to the direction of thrust. In this respect, it is ensured that the displacement of the wedge element leads to a uniform displacement of the side shift. In this case, it is particularly advantageous, in turn, to use an adjusting spindle, which can be mounted in the device carrier and leads to its displacement in the wedge element. It is also conceivable to store the adjusting spindle axially fixed in the wedge element and to provide the adjusting thread in the device carrier.

As an alternative to aligning the direction of adjustment of the wedge element perpendicular to the axis of rotation, it is possible when using a hydraulic or pneumatic or electric drive to select the adjustment direction parallel or coincident with the axis of rotation. Since no accessibility for operation is required in this case, it is irrelevant that the actuator is so far completely arranged in the clamping device or behind a recorded workpiece.

Although a positioning of the wedge element is predetermined via the wedge guides engaging in the side sliders on both sides in conjunction with the actuator, it is particularly advantageous if the wedge element is in turn mounted in a linear guide in the device carrier. This ensures in particular that there is no jamming or jamming of the wedge element during adjustment.

Furthermore, it is possible to adjust the sideshifter to adjust this example, as the base jaw carrier of a regular three-jaw chuck. Thus, it is possible to provide a basically any number of side sliders with the respective coupling arrangements. Likewise, thereby a reaction is opened, wherein a part of the advantageous embodiment of a clamping device is realized by an existing three jaw chuck with the base jaws of the three-jaw chuck as three sideshifter and the upper part of the device carrier is mounted with the clamping base carriers and the relevant coupling arrangement as a unit on the three-jaw chuck.

In the following figures example clamping devices are sketched with different coupling of clamping base, outer rocker and center rocker: show:

1 a plan view of a clamping device;

2 a section through the clamping device 1 ;

3 a perspective view of the relevant components of the clamping device 2 ;

4 a plan view of an alternative clamping device;

5 a section through the clamping device 4 ;

6 a perspective view of the essential components of the embodiment 5 ;

7 a perspective view of the essential components for a further alternative drive;

8th a perspective view of the essential components of an embodiment for six clamping base support;

9 an exemplary coupling between external rocker and center rocker;

10 an alternative coupling of external rocker and center rocker;

11 a coupling with a separate engagement element between the outer rocker and the center rocker;

12 an alternative coupling between external rocker and clamping base support.

In the 1 FIG. 10 is a plan view of a first embodiment of an exemplary tensioner. FIG 01 outlined. To recognize is first of all the food top 05 , by doing 05 four star-shaped clamping base support 11 each in a carrier guide 17 are mounted linearly displaceable. Furthermore, to recognize the arrangement of jaw guides 18 in the respective clamping base carriers 11 , this one 18 a locking teeth 19 assigned to secure the position of a mounted jaw. In this respect, this embodiment initially does not differ from the known embodiment of a clamping device with four clamping base carriers.

In the in 2 illustrated section through the clamping device 01 out 1 the coupling according to the invention between the elements becomes visible. To recognize is first of all the food upper part 05 on the top and the bottom of the food 06 on the side facing the lathe. In the middle is the axis of rotation 04 , About what 04 when used as intended, the clamping device 01 is rotatably mounted on the lathe. In the carrier guides 17 are each the clamping base support 11 radially displaceable. In this embodiment, the clamping base support 11 one tangential transverse guide each 13 on, in the 13 a slider 12 is linearly displaceable. The slider 12 is a coupling axis 14 swiveling on an external rocker 21 stored. The outside rocker 21 in turn, is about a pivot axis 34 pivotable on a side gate 31 stored. This page slider 31 is also radial to the axis of rotation 04 slidable in the clamping device 01 stored. The drive of the sideshifter 31 takes place in this embodiment using wedge guides 32 through a wedge gate 33 , This 33 can be perpendicular to the thrust direction of the sideshift 31 through a drive spindle 35 be adjusted.

The transmission of the pivoting movement of an external rocker 21 on the opposite outdoor rocker 21 using a center rocker 28 takes place by the engagement of an engagement element 22 in a linear guide 23 ,

To this end, the following outlines 3 the relevant components for the transmission of the movement in perspective view. On the one hand, two of the four existing clamping base beams can be seen 11 , Which 11 each in the carrier guide 17 in the tensioning device 01 are radially displaceable. In the clamping base support 11 is the jaw guide 18 for receiving a clamping jaw, wherein its position in the radial direction by engagement in a locking toothing 19 can be secured. On the underside there is a tangentially oriented transverse guide 13 , along the 13 the slider 12 is linearly displaceable. The slider 12 has a coupling axis 14 on, wherein for storage of the external rocker 21 on the slider 12 this 12 a bearing pin 15 which has 15 in a bearing sleeve 16 the outside rocker 21 is included. The outside rocker 21 in turn is about the pivot axis 34 swiveling on the side slide 31 stored. For this purpose, this embodiment has a bearing sleeve 26 on, in the 26 a bearing bolt 25 of the sideshifter 31 intervenes. The drive of the external rockers 21 is done by adjusting the sideshift 31 using a wedge guide 32 , for which purpose a wedge slide 33 perpendicular to the thrust direction of the sideshifter 31 is adjustable. The drive takes place in this embodiment by means of a drive spindle 35 ,

For coupling the opposite outdoor rockers 21 through an intermediate middle rocker 28 has the center rocker 28 opposite radially aligned linear guides 23 on. In these 23 engage each engagement elements 22 the respective outdoor rockers 21 one. To enable the pivoting of the external rockers 21 Here are the engagement elements 22 partially executed in the form of a cylinder bolt, these 22 in the direction of the engagement axis 24 are aligned. This allows pivoting of the external rockers 21 around the engagement axis 24 with simultaneous displacement along the linear guide 23 ,

In the following 4 is another embodiment of a clamping device 01 outlined. Outlined here 5 again a section through the clamping device 01 analogous to the previous variant. In contrast to the execution 2 has the embodiment 5 a modified drive to move the sideshifter 41 on. The clamping base support 11 as well as the outside seesaws 21 , the sliding body 12 as well as the center rocker 28 are executed analogously to the previous variant.

Deviating from the previous version of the side shift 41 with a wedge gate 43 coupled, which 43 in the direction of the axis of rotation 04 for example, by a hydraulic drive is displaced. Otherwise, an adjustment of the sideshift occurs 41 by means of a wedge guide 42 similar to previous version.

Outlined here 6 the individual parts in perspective view.

In the following 7 is in perspective another drive for adjusting the side shift 51 outlined. For this purpose, the opposite side shift 51 each with a left-hand thread 52 or a right-hand thread 52 provided, both sideshift 51 by an adjusting spindle aligned in thrust direction 53 with left-hand thread 52 and right-hand thread 52 are connected. To secure the centric position of adjusting spindle 53 and thus the sideshifter 51 Furthermore, the adjusting spindle 53 centered by a spindle bearing 55 in the tensioning device 01 centered. By turning the adjusting spindle 53 Immediately a movement of the side shift 51 towards or away from each other.

Although the embodiment with four jaws already allows an advantageous clamping of non-circular workpieces, the embodiment is readily further clamping base support 11 expandable. This outlines the 7 schematically a variant with six clamping base beams 11 , Which 11 are coupled via three outdoor rockers by means of three side shifters.

In the sequence of figures 9 exemplifies the coupling of the opposite outer rockers 21 outlined. First of all, the arrangement of opposing outdoor rockers can be recognized 21 , Which 21 each about the pivot axis 34 pivotally mounted on the respective side sliders - see 9a , Furthermore, the two outdoor rockers 21 coupling axes 14 on, over the 14 the adjustment of the respective clamping base support 11 he follows. The coupling of the opposite outdoor rockers 21 takes place by arranging a radially oriented linear guide 23 on the center rocker 28 , being inside the linear guide 23 each an engagement element 22 the respective outdoor rocker 21 is linearly displaceable. In addition, the respective external rocker 21 one to the engagement element 22 associated engagement axis 24 pivoted.

Now done an adjustment of the side shift 21 on the axis of rotation 04 to, then become the engagement elements 22 linear along the linear guide 23 postponed - see 9b , If, on the other hand, there is a swinging of an external rocker 21 , For example, due to the investment of a first clamping base support, about the pivot axis 34 , this leads to a corresponding adjustment of the associated engagement element 22 - please refer 9c , This leads due to the definition of the coupling axis 24 within the linear guide 23 Immediately to an opposite swinging the center rocker 28 , As a result, immediately becomes the opposite outdoor rocker 21 swung analog.

In the 10 is an alternative embodiment for coupling the outer rocker 61 with the center rocker 68 outlined. In this embodiment, the linear guide 63 in the outside rockers 61 integrated, in contrast, the center rocker 68 integrally associated engagement elements 62 having.

Although not mandatory, it is also possible to use the engagement elements 73 as separate components, as shown in 11 is sketched to execute. In this respect, a storage of the separate engagement elements 72 linear along the linear guide 73 displaceable. Here is the center rocker 78 coincident with the previous example about the engagement axis 24 pivotable, but now relative to the engagement elements 72 ,

In the 12 By way of example, an alternative coupling of the outer rockers on the side slide or on the clamping base support is outlined. In this embodiment, it is provided that the outer rockers 81 each on both sides integral sliding body 82 exhibit. This in the form of a cylinder pin in the direction of the coupling axis 14 aligned slider 82 can be stored directly in the transverse guide of the clamping base support. Note, however, the reduced load bearing when clamping a workpiece to ensure its functionality over a long period of time. Furthermore, this embodiment, the outer rocker 81 a bearing pin 85 on which 85 in the direction of the pivot axis 34 is aligned and can be accommodated in a bearing sleeve of the side slider.

LIST OF REFERENCE NUMBERS

01

jig

04

axis of rotation

05

Lining shell

06

Forage base

11

Clamping base support

12

sliding

13

width guide

14

coupling axis

15

bearing bolt

16

bearing sleeve

17

carrier guide

18

jaw guide

19

locking teeth

21

outside rocker

22

engaging member

23

linear guide

24

axis of engagement

25

bearing bolt

26

bearing sleeve

28

mid rocker

31

Sideshift

32

wedge guide

33

wedge slide

34

swivel axis

35

drive spindle

41, 51

Sideshift

42

wedge guide

52

Left / right-hand thread

43

wedge slide

53

adjusting spindle

55

spindle bearing

46

wedge slide

61, 71

outside rocker

62, 72

engaging member

63, 73

linear guide

68, 78

mid rocker

81

outside rocker

82

sliding

85

bearing bolt

Claims (9)

Clamping device ( 01 ) for use on a lathe with at least four star-shaped to a rotation axis ( 04 ) slidably mounted clamping base beams ( 11 ) and with at least two outdoor rockers ( 21 . 61 . 71 . 81 ), Which ( 21 . 61 . 71 . 81 ) in each case directly or indirectly hinged with adjacent clamping base beams ( 11 ) are coupled with at least two side sliders ( 31 . 41 . 51 ), Which ( 31 . 41 . 51 ) each in a radial to the axis of rotation ( 04 ) extending thrust direction are movable and where ( 31 . 41 . 51 ) each have an external rocker ( 21 . 61 . 71 . 81 ) is pivotally mounted, and with a pivotally mounted center rocker ( 28 . 68 . 78 ), Which ( 28 . 68 . 78 ) directly or indirectly with at least two external rockers ( 21 . 61 . 71 . 81 ), characterized in that at least two outer rockers ( 61 . 71 ) one perpendicular to the axis of rotation ( 04 ) running linear guide ( 63 . 73 ), along the ( 63 . 73 ) an engagement element ( 62 . 72 ) is displaceable, which ( 62 . 72 ) one parallel to the axis of rotation ( 04 ) extending engagement axis ( 24 ) in order to 24 ) the center rocker ( 68 . 78 ) is pivotally mounted; or that the center rocker ( 28 ) at least two perpendicular to the axis of rotation ( 04 ) extending linear guides ( 23 ) along which ( 23 ) each an engaging element ( 22 ) is displaceable, which ( 22 ) one parallel to the axis of rotation ( 04 ) extending engagement axis ( 24 ) in order to 24 ) the respective external rocker ( 21 . 81 ) is pivotally mounted. Clamping device ( 01 ) according to claim 1, characterized in that the linear guides ( 23 . 63 . 73 ) with four clamping supports ( 11 ) and two outdoor rockers ( 21 . 61 . 71 . 81 ) opposite the axis of rotation ( 04 ) are arranged; or that the linear guides in six clamping base beams ( 11 ) and three outer rockers at 120 ° about the axis of rotation ( 04 ) are arranged offset. Clamping device ( 01 ) according to claim 1 or 2, characterized in that the linear guides ( 63 . 73 ) in a middle position of the respective outer rocker ( 61 . 71 ) extend radially; or that the linear guides ( 23 ) of the center rocker ( 28 ) extend radially. Clamping device ( 01 ) according to one of claims 1 to 3, characterized in that the center rocker ( 68 ) the engagement elements ( 62 ) integral or fixed; or that the external rockers ( 21 . 81 ) the respectively associated engagement element ( 22 ) integral or fixed. Clamping device ( 01 ) according to one of claims 1 to 3, characterized in that the engagement elements ( 72 ) about the respective engagement axis ( 24 ) pivotable on the center rocker ( 78 ) are stored; or that the engagement elements about the respective engagement axis are pivotally mounted on the respective outer rocker. Clamping device ( 01 ) according to one of claims 1 to 5, characterized in that the clamping base support ( 11 ) each have a tangential transverse guide ( 13 ), along the ( 13 ) a slider ( 12 . 82 ) is displaceable, which ( 12 . 82 ) one parallel to the axis of rotation ( 04 ) extending coupling axis ( 14 ) in order to 14 ) the associated external rocker ( 21 . 61 . 71 . 81 ) is pivotally mounted; or that the outer rockers each have two transverse guides extending perpendicularly to the axis of rotation, along which a respective sliding body is displaceable, which has a coupling axis extending parallel to the axis of rotation about which the respectively associated clamping base support is pivotably mounted. Clamping device ( 01 ) according to claim 6, characterized in that two sliding bodies ( 12 ) about the respective coupling axis ( 14 ) pivotable on an external rocker ( 21 . 61 . 71 ) are stored; or that the sliding bodies are mounted pivotably about the respective coupling axis on the respective clamping base carrier. Clamping device ( 01 ) according to one of claims 1 to 7, characterized in that an adjusting spindle ( 53 ) in a first side shifter ( 51 ) with a left-hand thread ( 52 ) and in a second opposite side shifter ( 51 ) with a right-hand thread ( 52 ) is mounted, wherein a rotation of the adjusting spindle ( 53 ) to an opposite movement of the sideshifter ( 51 ) leads to or away from each other, in particular the adjusting spindle ( 53 ) is rotatably mounted and fixed in the direction of slide. Clamping device ( 01 ) according to one of claims 1 to 7, characterized in that a wedge slide ( 33 . 43 . 46 ) is displaceable in a drive direction perpendicular to the slide direction and via a respective wedge guide ( 32 . 42 ) with a Sideshift ( 31 . 41 ), wherein an actuating movement of the wedge slide ( 33 . 43 . 46 ) to a movement of the sideshifter ( 31 . 41 ) on the axis of rotation ( 04 ) to respectively leads away from this.

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