EP0237136A1 - Device for retaining and manipulating a flat object - Google Patents

Abstract

The device for holding and handling a flat object (W), which can be a work piece to be machined or a tool therefor, clamps the object between a fixed jaw (1.1) and a movable jaw (1.3). The device has a closed, rectangular, flat frame (1), one side of which is designed as the fixed clamping jaw (1.1).

A movable clamping jaw (1.3) can be inserted into the frame (1) from the outside and can be moved therein. It is equipped with means (1.3.5, 1.3.6 and 1.3.7) for clamping it to the frame (1) and can be braced against the flat object (W).

At least one clamping means (1.5) acting on the movable jaw (1.3) is provided on the side (1.4) of the frame (1) opposite the fixed jaw (1.1).

The device enables the flat object to be clamped without play and warping. It is particularly suitable for precision machining in one or more successive work steps, with a preset processing position of the object being maintained in the course of the machining.

Description

The invention relates to a device for holding and handling a flat object, in particular for holding a flat workpiece on a machine tool according to the preamble of claim 1.

A device has already become known which is also said to be suitable for holding flat workpieces for machining on a machine tool (Tech. Rundschau I.86, workshop, accessories for wire EDM machines). It is adjustable Wrench, a so-called Englishman, and also has similarities to a vice. This device, however, has the important disadvantage that it represents a system that is open on one side and is therefore not able to clamp a workpiece without play and distortion. Since certain machining processes, such as electrical spark erosion, require a play-free maintenance of a workpiece position that is set with high precision and free of tension during machining, the use of the known device is not very useful in such cases.

The object of the invention is therefore to improve the generic device in such a way that it allows fast, tension-free and play-free clamping of the objects for the purpose of precision machining of flat objects. In addition, the respective machining process should not be obstructed by parts of the device if possible. Furthermore, the preset processing position of the object is to be ensured in successive operations on the firmly clamped object on changing processing machines, automatic handling or transport between the different processing machines should also be possible.

The object of the invention is achieved in the generic device by the features specified in the characterizing part of claim 1. Advantageous refinements and developments of the invention can be found in the subclaims. The device according to the invention, which is also referred to below as a "frame clamp", enables a precise, tension-free and play-free manner in a rigid, closed system Holder of the flat object and is therefore particularly advantageously applicable for machining operations that require extreme precision.

The flat object is clamped in two steps:
First of all, the movable jaw is inserted into the frame and carefully clamped to the object to be clamped with clamping means, but without play, and clamped;
then the movable jaw is clamped by the clamping means with a superimposed support bracing on the frame, which is equivalent to a lock.

The device represents a relatively simple construction, the parts of which, in particular the movable jaw, are easily interchangeable. This allows a quick adaptation to different types and contours of objects to be obtained.

Another significant advantage of the device according to the invention is that it enables unhindered processing of the object clamped in it up to its outer contour, so that it can also be completely separated if necessary, without the separate parts being able to change their position.

The respective flat object can be a workpiece to be machined or a tool. For example, the flat object can represent a sinking electrode during spark erosion, which is clamped in the box clamp and fastened to a sinking EDM machine.

The box clamp can also be used to "palletize" high-precision clamped objects, in particular workpieces. If you want to carry out a sequence of machining operations on different machines while maintaining the required workpiece position with respect to a reference point on a preset position, you can simply clamp the box clamp with the workpiece on the different machines without changing the relative position of the workpiece in relation to the reference system . This gives a high repeat accuracy of a defined machining position of the workpiece each time a new work step begins.

With the features of claims 2 and 3, a simple and quick insertion of the movable jaw into the frame and, on the other hand, a play-free application of this jaw to the object to be clamped is achieved. With the features of claim 6 you get an adaptation of the box clamp to the outline of different objects to be clamped.

With claim 7 it is achieved that when clamping the flat object as small as possible, but clean contact surfaces between the object and the frame clamp arise, so that processing waste and dirt can be removed and that in the case of machining by means of wire erosion, the threading of the wire electrode without starting hole drilling is possible is.

With claim 9, the clamping process is facilitated, especially with regard to a semi or fully automatic clamping.

Claims 10 and 11 offer the possibility of automatically handling the box clamp and combining it with other handling devices according to the applicant's earlier patent applications.

• Fig. 1 eine Draufsicht der Vorrichtung nach der Er­findung;
• Fig. 2 einen teilweise weggebrochenen Schnitt längs der Linie I-I der Fig. 1;
• Fig. 3 eine perspektivische Darstellung der beweg­lichen Klemmbacke, die bei der Erfindung ver­wendet wird;
• Fig. 4 eine Draufsicht auf eine bewegliche Klemmbacke gemäß einer Weiterbildung der Erfindung, wobei ein Teil einer Ecke weggebrochen ist;
• Fig. 5 ein erstes Beispiel für die Verwendung der Vorrichtung nach der Erfindung bei einem Hand­habungssystem für die Präzisionsbearbeitung flacher Werkstücke;
• Fig. 6 ein zweites Verwendungsbeispiel für die Vor­richtung; und
• Fig. 7 ein drittes Verwendungsbeispiel für den Ein­satz der Vorrichtung.

The invention is explained in more detail below on the basis of exemplary embodiments in conjunction with the drawing. It shows:

• Figure 1 is a plan view of the device according to the invention.
• Figure 2 is a partially broken section along the line II of Fig. 1.
• Figure 3 is a perspective view of the movable jaw used in the invention;
• 4 shows a plan view of a movable clamping jaw according to a development of the invention, with part of a corner broken away;
• 5 shows a first example of the use of the device according to the invention in a handling system for the precision machining of flat workpieces;
• 6 shows a second example of use for the device; and
• Fig. 7 shows a third example of use for the use of the device.

The device shown in Fig. 1 has a closed, rectangular, flat frame 1, one (on the right in Fig. 1) transverse side is designed as a fixed jaw 1.1. Furthermore, the device has a movable clamping jaw 1.3, which can be inserted into the frame from the outside and is guided on its longitudinal sides 1.2. The jaw 1.3 can on the long sides 1.2 of the frame 1 are clamped and it can be clamped against a flat object W to be held (cf. also FIGS. 2 to 4). The left-hand transverse side 1.4 of the frame 1 in FIG. 1 carries a clamping means 1.5 acting on the movable clamping jaw 1.3, which in the present embodiment consists of three screw bolts 1.5.1 each inserted in a threaded hole 1.4.1 of the left-hand transverse side 1.4. According to a variant (not shown) of the invention, hydraulically or pneumatically actuated pressure drives can also be used as clamping means 1.5.

The rigid frame 1 and the precise guidance of the movable clamping jaw 1.3 explained in more detail below enable precise, play-free and distortion-free clamping of the flat object W to be held.

As can be seen in particular from FIGS. 2 and 3, the movable clamping jaw 1.3 essentially has the shape of a cuboid, which is provided with a groove 1.3.1 on both of its smallest side faces. In plan view of the movable clamping jaw 1.3, the respective groove base 1.3.2 has an arcuate course (cf. dashed lines in FIGS. 1 and 4). The arcuate course of the groove base 1.3.2 of the two opposite grooves is designed in such a way that one groove (upper groove in FIG. 1) has a deep incision in the direction from the workpiece side, which decreases steadily towards the clamping device side, while the bottom of the other groove (bottom in FIG. 1) seen from the workpiece side initially has a small incision depth, which increases steadily towards the back toward the clamping device side. In other words, the bottom of the groove is cut deeper in diagonally opposite corners of the movable jaw cut flatter in the other diagonally opposite corners. The deeper incision lies at the corners, which is closer to the guide bar 1.2.1 when the movable clamping jaw 1.3 is inserted into the frame 1 (cf. dashed position of the clamping jaw in FIG. 1) (cf. also FIGS. 4 to 6). As indicated by dash-dotted lines in Fig. 1, the insertion of the movable jaw 1.3 in the frame begins in an inclined position. It is advantageous if the corners of the movable jaw 1.3 are rounded or beveled.

The two grooved ends of the movable jaw 1.3 are each split by a slot 1.3.3 in two prongs 1.3.4 (Fig. 3). The slots 1.3.3 each extend from the center line of each groove base 1.3.2 parallel to the largest side surface of the movable jaw 1.3 towards the center thereof. They therefore run approximately in the center plane of the frame 1. The associated tines 1.3.4 on both sides of the clamping jaw 1.3 can spring slightly towards one another due to the slot 1.3.3 that forms them, and can thus be braced on the guide bar 1.2.1 of the respective longitudinal frame side 1.2 . Each pair of associated tines 1.3.4 has a hole with a common axis running perpendicular to the slot plane. Hole 1.3.5 in one prong is a through hole with smooth walls. The other coaxial 1.3.6 hole in the other prong 1.3.4 is a threaded hole. The pairs of associated tines 1.3.4, each of which clasp the guide bar 1.2.1 on the inside of the facing longitudinal side of the frame 1.2, can then ge using a countersunk screw 1.3.7 interacting with the threaded bore 1.3.6 against the guide bar 1.2.1 presses and clamped to it without play (cf. in particular Fig. 2).

Instead of the bores 1.3.5, 1.3.6 and the countersunk screws 1.3.7, the pairs of associated tines 1.3.4 can also be clamped to the associated guide bar 1.2.1 by means of a pressure drive with hydraulic or pneumatic actuation.

If the flat object W to be held has non-parallel but straight side surfaces, the movable clamping jaw 1.3 can also be designed with a pressure side which is inclined at an angle to the longitudinal sides 1.2 of the frame.

In order to adapt to an outline of flat objects W with an irregular or curved course, the surfaces of the clamping jaws 1.1 and 1.3 and also those of the longitudinal sides of the frame 1.2, each of which comes into contact with the side surfaces of the object W, can be designed as special profiles 1.6, as shown in FIG Fig. 4 is shown for a simple example with a circular contour.

Fig. 1 further shows that the surfaces facing the workpiece W of the fixed jaw 1.1, the movable jaw 1.3 and the guide rails 1.2.1 have incised grooves 1.7, which here has a semicircular cross section and which are perpendicular to the frame plane. The grooves can also have another shape, for example a triangular cross section. The effective contact surfaces are reduced by these grooves 1.7. However, this makes it possible to keep these contact surfaces cleaner and in particular to remove waste items, dirt such as metal chips etc. Furthermore, in the case of machining by wire erosion, the wire electrode can also be threaded into these grooves.

From Fig. 2 it can be seen even more clearly that the width of the grooves 1.3.1 and the width of the guide strips 1.2.1 is adapted such that be not tightened countersunk screw 1.3.7, the movable jaw can be easily moved relative to the frame can, but it is firmly clamped to the guide bar 1.2.1 when the countersunk screw 1.3.7 is tightened.

FIG. 5 shows a first example of use of the device according to the invention for the purpose of automated handling of a tightly clamped flat object W when it is processed by the wire electrode D of a wire EDM machine, not shown, in a handling system 2 with a flat slide 2.1 that can be moved in X, Y coordinates according to an earlier patent application by the applicant. 5 shows one of two grooves 2.1.1 each formed on the two longitudinal sides of the flat slide 2.1. The visible front groove 2.1.1 has a trapezoidal cross-sectional area. In contrast, the other groove (not visible in FIG. 5) is provided with a triangular cross-sectional area. The two edge surfaces of the adjacent flat slide side, which are close to the grooves 2.1.1, are designed as finely or precisely machined guide surfaces, while the front groove 2.1.1 has a surface created by milling and less precisely dimensioned.

The flat slide 2.1 is guided along the guide jaws of a mobile base 2.2 using the grooves 2.1.1, of which only one 2.2.1 is visible in FIG. 5. The guide jaw 2.2.1 engaging in the front groove 2.1.1 is provided with a locking device 2.2.2 for locking the flat slide 2.1. The base 2.2 can in turn be displaced at right angles to the direction of movement of the flat slide 2.1 by means of guide jaws 2.3, these guide jaws 2.2.3 in turn having grooves 2.3.1. described type of a bar 2.3 are performed. The bar 2.3 directed transversely to the flat slide 2.1 is mounted on a frame 2.4. The flat slide 2.1 is connected by means of fastening screws 2.1.2 and adjusting screws 2.1.3 to the fixed jaw 1.1 of the box clamp according to FIG. 1. By means of the adjusting screws 2.1.3, a fine adjustment of the box clamp and flat slide 2.1 in a horizontal plane is made by very small partial swiveling movements of material areas, in each case in the vicinity of an adjusting screw 2.1.3 approximately by parallel to the grooves 2.1.1. of the flat slide 2.1 possible axes.

Another possibility for fine adjustment of the flat slide 2.1 with regard to its unimpeded displaceability or precise guidance between the guide jaws 2.2.1 of the mobile base 2.2 is provided by an essentially U-shaped slot 2.1.4, which is then attached to the area of the fastening and adjusting screws 2.1.2 and 2.1.3 is formed in the flat slide 2.1. At right angles to the two legs of the U-shaped slot 2.1.4, a threaded hole (not visible in FIG. 5) is machined into the flat slide 2.1, which, on both sides of the U-shaped slot 2.1.4, runs in opposite directions from one leg of the same into the groove 2.1 .1 open on the respective closer longitudinal side of the flat slide 2.1. With the help of one inserted in the threaded holes The setscrew 2.1.5, the inner end of which rests against the corresponding side of the rectangular material region of the flat slide 2.1 enclosed by the U-shaped slot 2.1.4, can then be fine-tuned to match the grooves 2.1.1 of the latter to the guide jaws 2.2.1 of the mobile pedestal in turn by a slight partial rotary movement about a vertical axis. 5 is identical to that shown in FIGS. 1 to 3.

A box clamp of a similar design is also shown in FIG. 6. It is mounted on a pallet 1.9 using holes 1.8 provided in frame 1 and screws 1.8.1 inserted into them. For the purpose of handling, the pallet 1.9 has grooves 1.9.1 which are designed similarly to the grooves 2.1.1 of the flat slide 2.1 according to FIG. 5.

FIG. 7 shows the use of a box clamp according to FIGS. 1 to 3 in a further handling system 10, which permits processing of an object W clamped in the box clamp from both sides, regardless of whether this object is flat or on both sides the box clamp protrudes. The handling system is based on the arrangement according to FIG. 5. Analogously, the box clamp is mounted on a flat slide 12.1 and this is slidably arranged with side grooves 12.1.1 between guide jaws 12.2.1 on the upper longitudinal edges of a mobile base 12.2. In this case, two slots 12.1.4 are provided in the flat slide 12.1, which run obliquely from the central area of the flat slide 12.1 and each extend to the corresponding groove 12.1.1 via a kink.

The pedestal 12.2 is then guided by means of further guide jaws 12.2.4 of the same type provided on its lower longitudinal edges in a pair of grooves 12.3.1 which run along the upper longitudinal edges of a bar 12.3 aligned parallel to the movement of the flat slide 12.1 and with regard to their cross-sectional areas and Surface texture are movable to play the grooves 12.1.1 of the flat slide 12.1.

The beam 12.3 used to guide the base 12.2 in parallel is also provided with a pair of grooves 12.3.2 machined in its lower longitudinal edges, which correspond to those 12.1.1 of the flat slide 12.1 with regard to their cross-sectional area and surface quality.

In order to enable processing of the object W from the lower side of the box clamp, which is invisible in FIG. 7, it can be attached together with the flat slide 12.1 and the mobile base 12.2 to the underside of the beam 12.3 used for parallel guidance, by the lower guide jaws 12.2.4 of the pedestal 12.2 are inserted into the lower grooves 12.3.2 of the beam 12.3 so that the flat slide 12.1 and the box clamp together with the object W to be processed point downward in a position rotated by 180 ° about the longitudinal axis of the beam.

Other embodiments and types of use of the device according to the invention are also possible. The flat slide 2.1 in the arrangement according to FIG. 5 can be replaced by a circular cylindrical shaft which can be guided in a housing and is limited in terms of its axial and rotary movements. It is also in the same arrangement according to FIG. 5 instead of one fold clamp, a multiple frame clamp can also be used, although the direction of movement or clamping of the associated movable clamping jaws should be directed at right angles to the stroke direction of the respective carrier (flat slide, cylindrical shaft, etc.). The flat slide 12.1 of the arrangement according to FIGS. 7 and 5 could finally be designed similarly to the beam 12.3 used for parallel guidance with a cross section corresponding to the beam 12.3 and also with four grooves identical to those of the beam. Such a slide would then also be insertable between the guide jaws 12.2.1 of the base 12.2 in a position rotated by 180 ° about its longitudinal axis.

Claims (11)

1. Device for holding and handling a flat object, in particular for holding a flat workpiece on a machine tool, the object (W) being able to be clamped between a fixed jaw (1.1) and a movable jaw (1.3), characterized by: a) a closed, rectangular, flat frame (1), one side of which is designed as the fixed jaw (1.1), b) by means of a movable clamping jaw (1.3) which can be inserted into the frame (1) from the outside, is guided in it and can be braced against the flat object, c) clamping means (1.3.5, 1.3.6, 1.3.7) for clamping the movable clamping jaw (1.3) on the frame (1) and d) at least one chip (1.5) acting on the movable jaw (1.3), which is provided on the side of the frame (1.4) opposite the fixed jaw (1.1). 2. Device according to claim 1, characterized in that the movable clamping jaw (1.3) has essentially the shape of a cuboid and has a groove (1.3.1) in each of its two opposite end faces, into each of which a guide strip (1.2. 1) engages, which are provided on mutually facing inner surfaces of the longitudinal sides (1.2) of the frame (1). 3. Device according to claim 1 or 2, characterized in that the two grooves (1.3.1) seen in plan view of the movable jaw (1.3) have an arcuate course of their groove base (1.3.2) and that in the direction from a front ( which points to the object) to a rear side (which points to the clamping means) of the movable clamping jaw (1.3) which has a groove with a constantly increasing depth and the other groove with a constantly decreasing depth. 4. Device according to one of claims 1 to 3, characterized in that the movable jaw (1.3) on both of them on the frame (1) out th sides are each split into two prongs (1.3.4) by a slot (1.3.3) that extends parallel to the largest side surfaces of the movable clamping jaw (1.3) towards the center thereof, the respective slot (1.3. 3) begins in particular in the groove base (1.3.2) so that the two prongs (1.3.4) can be clamped to the frame by the clamping means (1.3.5, 1.3.6, 1.3.7). 5. The device according to claim 4, characterized in that the slots (1.3.3) are offset from a normal to the slot plane bore, the bore in each of the pair of tines (1.3.4) a threaded bore (1.3.6 ), into which a screw (1.3.7) can be screwed, which presses the two prongs (1.3.4) of a pair that belong together against the guide bar (1.2.1) engaging in the respective groove (1.3.1). 6. Device according to one of claims 1 to 4, characterized in that the side surfaces of the clamping jaws facing the object to be clamped (1.1, 1.3) and, if appropriate, also the surfaces of the longitudinal sides (1.2) of the frame (1) facing the object (W) have special profiles (1.6) adapted to the contour of the object. 7. Device according to one of claims 1 to 6, characterized in that the object (W) facing sides of the jaws (1.1, 1.3) and the long sides (1.2) of the frame (1) perpendicular to the plane of the frame grooves (1.7 ), in particular with a semicircular cross section. 8. Device according to one of claims 1 to 7, characterized in that the clamping means (1.5) are bolts (1.5.1) which are arranged in threaded bores (1.4.1) of the fixed jaw (1.1) opposite the frame side (1.4) . 9. Device according to one of claims 1 to 4, 6 or 7, characterized in that the clamping means (1.3.5, 1.3.6, 1.3.7) and the clamping means (1.5) are each a hydraulic or pneumatic pressure drive. 10. Use of the device according to claims 1 to 9 for the holding and handling of a flat object (W) in the course of successive machining operations. 11. Use according to claim 10, in which the device is fastened to a pallet (1.9) by means of bores (1.8) provided in its frame (1) and screws (1.8.1) inserted therein, or provides another handling aid, in particular at least a flat slide (2.1) that can be guided on a frame (2.3, 2.4) with a special design by means of grooves (2.1.1, 2.3.1) or a shaft that can be guided in a cylinder housing, the latter using fastening screws (2.1.2) and adjusting screws (2.1 .3) are each connected to the fixed jaw (1.1), is further conveyed between processing machines.

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