EP0818254B1 - Transfer arrangement for metal sheets in a press plant - Google Patents

Description

The invention relates to a transfer device with the features of the preamble of claim 1.

In press systems with several press stages which are arranged one behind the other along a parts flow path, transfer devices are provided which remove the corresponding sheet metal parts from the press stages and feed them in cycles to the following press stage. Intermediate shelves are usually provided between the individual press stages, on which the workpieces to be transported can be temporarily stored, which makes it possible to reduce the width of the transfer step. To carry out the transfer, a transfer device is used which grips the workpieces when the tool is open and leads out of the tool in a transfer movement in which a lifting movement is superimposed on a horizontal transfer movement or inserted into it, the transfer movement being superimposed on a vertical lowering or depositing movement.

In particular in the case of workpieces and / or workpieces of complex design that are to be inserted into tools at an angle, that is to say deviating from a horizontal plane, it may be necessary to transfer the workpiece during transfer, for example during the removal or insertion from or into the tool to swivel a transverse axis. With appropriate tool and workpiece shapes, this may be necessary to avoid a collision between the sheet metal part and the tool during the transfer movement. The first processing stage of press systems, possibly also a subsequent processing stage, is designed as a drawing stage. Further processing may require an inclined position of the sheet metal part in the lower tool. For one, z. For example, because of the high number of strokes, the lifting stroke cannot be chosen to be as large as required, and secondly, it is necessary to pass angled, lowered drawing surfaces freely above the shape of the lower tool by deep drawing.

A corresponding conversion device has become known from EP-A-0 499 901. The transfer device includes two guide rails, which extend in the transfer direction and are arranged on the right and left sides next to the tools of the press stages, on which guide carriages are mounted. The guide rails are connected to a lifting and lowering unit in order to carry out a targeted horizontal movement. The carriages are connected to a transfer drive unit so that they can be moved along the rails in a targeted manner. A crossbar is arranged between two carriages and is rotatably mounted on the end of the carriage. As a gripper for gripping and holding sheet metal parts, the cross-beam carries a suction spider, which has a number has vacuum feet to which vacuum can be applied. In order to be able to swivel the suction spiders around a transverse axis, the crossbar in question is connected at the end via a coupling to a swivel lever which can be swiveled by means of a drive cylinder provided on the carriage.

In order not to limit the usability of the transfer device to applications in which rotary movements of the workpieces are required in only one or in a few stations, all carriages must be equipped with appropriate rotating units. This complicates the construction and increases the weight of the transfer device and, in particular, of the carriage, which necessitates correspondingly higher acceleration and braking forces to be applied and is disadvantageous in terms of energy. In addition, the design requires considerable installation space, which reduces the permissible lifting height of the transfer system (the crossbars).

A transfer device should ideally be designed in such a way that it can handle a large number of workpieces, so that it can also be set up for future, unforeseeable tasks.

From JP-U-62-142431 a transfer device is known, in which a carrier carrying a suction spider is rotatably supported on a rotating unit as a whole. The rotating unit is held on a support that can be moved vertically up and down and horizontally.

If a corresponding transfer device is to have a plurality of such cross members, a rotary unit is required at each cross member position, regardless of whether the suction spider actually pivots for the specific application and at the respective position is needed. This is reflected in the design effort and the weight of the transfer device.

Proceeding from this, it is an object of the invention to provide a transfer device which enables high variability.

This object is achieved with a transfer device which has the features of patent claim 1:

The cross members, which are rigid in themselves, each have rotatably mounted suction spiders. In addition, the crossmember carries the drive means, for example a geared motor, hydraulic or pneumatic drives, which pivot the gripper means as required. This creates the possibility of providing crossbeams with pivotable gripper means at positions of the transfer device which structurally correspond to those positions which are designed for crossbeams with non-pivotable gripper means. The end suspension of the crossbeams is of a uniform design, irrespective of whether the crossbeam in question carries pivotable gripping means or not. No rotating units acting on the ends of the crossbeams are required, which would have to be provided permanently on the carrying and guiding means, for example on carriages mounted on running rails. This enables the quick change from crossbeams with rotatable gripper means to crossbeams with non-pivoting gripper means and vice versa. The constructive structural and economic effort is thus reduced to the required level for each application. At the same time, the transfer device offers a high degree of variability and enables quick and easy adaptation to different, also future, transfer tasks.

Since drive means acting on the gripper means are only to be provided at those positions or crossbars at which they are actually required, the mass of the transfer device to be accelerated and braked is not increased by unnecessary drive devices which are also to be moved. This enables a quick transfer or a reduction in the drive / braking power.

The pivotable mounting of the gripper means on the crossbar and the assignment of a drive means carried by the crossbar to each gripper means creates the basis for the gripper means provided on one and the same crossbar being divided into gripper units to be controlled or pivoted differently. E.g. A first and a second suction spider can be provided on a crossbar, only one of which is pivoted or which is pivoted differently. Sheet metal parts that can be pivoted differently and are to be transported next to one another through the press stages can thus be handled. This can be necessary if two separate sheet metal parts are created from a circuit board, which are designed differently. The versatility of the transfer device according to the invention even makes it possible here for a sheet metal part which has been separated from it as a cutout to form a large opening in another sheet metal part to be transported synchronously with the latter and to be formed into a separate part. It can be held and transported with its own suction spider, which sits on the same cross-beam as the suction spider for the surrounding, larger part, and can also be transferred to other tilting angles.

A coupling arrangement between the crossbeam and the gripper means or a gripper unit formed from gripper means, bearing device and drive means can, if necessary, enable the gripper unit to be detached from the crossbars, so that the crossbars can be converted for a particular application. In particular, pivotable gripper means / units can also be exchanged for non-pivotable.

The axis of rotation of the gripper means is preferably within the crossbar, the center of gravity of the workpiece being below the crossbar. As a result, there is no appreciable torque acting on the drive means due to the weight of the workpiece.

In the case of a design that can be converted manually in a simple manner, the bearing device includes at least one split bearing unit that has two curved guide surfaces on which the gripper means are supported by rollers, a gear segment serving as a curved rack serving for coupling to a geared motor that serves as the drive means can be understood. This design enables a particularly low overall height of the swiveling gripper unit, which is not or hardly larger than that of an unmovable one. This does not restrict the permissible vertical stroke of the transfer device.

Further features of advantageous developments of the invention are the subject of dependent claims.

Fig. 1

eine Pressenanlage mit mehreren Pressenstationen und einer Zwischenablage, in einer ausschnittsweisen, stark schematisierten Seitenansicht,

Fig. 2

eine Transfereinrichtung für die Pressenanlage nach Fig. 1 mit zwei zueinander parallel angeordneten Laufschienen und darauf gelagerten Laufwagen, zwischen denen Quertraversen angeordnet sind, in stark schematisierter und vereinfachter Darstellung;

Fig. 3

eine Quertraverse der Transfereinrichtung nach Fig. 2 mit zwei jeweils mittels einer Dreheinrichtung separat um die Quertraverse drehbaren Greifereinheiten, in perspektivischer, vereinfachter Darstellung,

Fig. 4

eine Dreheinheit der Greifereinheit nach Fig. 3, in perspektivischer, schematisierter Darstellung und in einem anderen Maßstab, und

Fig. 5

die Dreheinheit nach Fig. 4 in einer Querschnittsdarstellung, geschnitten bei einer zu der Dreheinheit gehörigen Lagereinrichtung.

In the drawing, an embodiment of the invention is shown. Show it:

Fig. 1

a press system with several press stations and an intermediate storage, in a partial, highly schematic side view,

Fig. 2

a transfer device for the press system of Figure 1 with two mutually parallel running rails and trolleys mounted thereon, between which cross members are arranged, in a highly schematic and simplified representation.

Fig. 3

2 with two gripper units, each rotatable separately by means of a rotating device by means of a rotating device, in a perspective, simplified representation,

Fig. 4

3, in a perspective, schematic representation and on a different scale, and

Fig. 5

4 in a cross-sectional representation, cut in a bearing device belonging to the rotating unit.

description

1 illustrates a press installation 1 which has a sequence of press stations, two of which press stations 3, 4 are illustrated. Each press station 3, 4 has a sliding table 5, 6 for receiving a lower tool 7, 8, to which an upper tool 9, 10 held on a ram is assigned. The upper tools 9, 10 are moved up and down in cycles in the direction of the arrows 11, 12 by the tappets. Sheet metal parts 14, 15 are processed in stages in the press stations 3, 4. For the storage of a further sheet metal part 16 between the press stations 3, 4 as required, a clipboard 18 can be arranged halfway between the two sliding tables 5, 6. If necessary, this has templates that can be adjusted in several axes, in order to accommodate the sheet metal part when it is being stored and, if necessary, to align it in the vertical and inclined positions for further transport.

The sheet metal parts 14, 15, 16 are transported along a transfer curve 21, 22 from the press station 3 to the clipboard 18 and from there to the press station 4 or directly from the press station 3 to the press station 4. The transfer curves 21, 22 are formed by vertical lifting-lowering movements (V in FIG. 2) over which a horizontal transport stroke (H in FIG. 2) is superimposed. It may be necessary for the sheet metal part 14, 15 or 16 to be turned into such a tilted position in the lifting movement from the lower tool 7, 8 or during removal from the clipboard 18 that deep-drawn edges are not removed from the respective lower tool during transport 7, 8 or the inclusion of the clipboard 18 are hindered.

A transfer device 23 serves to transfer the sheet metal parts 14, 15, 16 and, if necessary, to pivot them, a partial section of which is shown schematically in extreme detail in FIG. 2. These include two lifting beams or runners 24, 25 arranged parallel to one another and parallel to a transport direction T, on each of which carriages 26, 27, 28, 29, 30, 31 are mounted so as to be movable in the transport direction T, each of which is only indicated schematically Linkage 32 are driven. Each in pairs between two carriages 26, 27; 28, 29; 30, 31, a crossbar 33, 34, 35 is held, the ends of which are detachably connected to the respective carriage 26, 27, 28, 29, 30, 31. Coupling means are used for the connection, as can be seen, for example, from FIG. 3.

Each cross-beam 33, 34, 35 carries as gripper means for the sheet metal parts 14, 15, 16 suction spiders 36, 37, 38, at least the suction spiders 37 held on the cross-beam 34 being rotatably mounted on the cross-beam 34.

As can be seen from FIG. 3, the cross-beam 34 has a continuous, rigid support formed from a box profile, which is provided at both ends with coupling halves 41, 42 for connection to the carriages 28, 29. The carrier carries two suction units 37a, 37b, which are mirror-symmetrical to one another. The following description relating to the suction unit 37a thus applies accordingly to the suction unit 37b.

The suction unit 37a includes a plurality of suction devices 46a connected to a frame 45a via arms 44a. The frame 45a is mounted on a bracket 48a via a bearing device 47a, which can be seen, for example, in FIGS supported, spaced-apart bases 49a, 50a can be coupled.

The holder 48a comprises the crossbar 34, as shown in FIG. 5, on three sides and is open at the bottom. The same applies to the part 48a 'of the holder connected to the base 50a.

On the holder 48a, 48a 'serving as coupling counterparts, spade-shaped extensions are formed as an insertion aid and coupling bolts are present which are received by the bases 49a, 50a and form a releasable coupling arrangement with these. Securing means prevent the clutch arrangement from being released unintentionally.

The bearing device 47a is formed by curved surfaces 52a, 53a formed on the holder 48a, 48a ', each lying in pairs on a common circle, the center M of which corresponds to the center of the crossbar 34 (FIG. 5). The frame 45a, which is also open at the bottom, is supported, for example, by a total of four rollers 56a, 57a, 58a, 59a on the curved surfaces 52a, 53a. As an alternative to this roller bearing, an arched profile rail guide would also be conceivable.

A gear segment 61a, which is connected to the frame 45a and is arranged laterally next to the rollers 58a, 59a, serves to couple the frame 45a to a servo motor 62a, which is arranged next to the holder 48a at the same height as the crossbar 34. The servo motor 62a is connected via a step-up gear, so-called harmonic drive gear 63a, to a lever 64 with a toothing at the end, which can also be understood as a gear segment and its toothing with the Gear segment 61a meshes. Its axis of rotation is aligned parallel to the axis of rotation of the frame 45a.

The press system 1 described so far and in particular the transfer device 23 operate as follows:

According to the cycle of the press ram of the press stations 3, 4 illustrated in FIG. 1, the running rails 24, 25 in the vertical direction V and the carriages 26, 27, 28, 29, 30, 31 in the horizontal direction H are moved by means of corresponding drive units A so that the Cross members 33, 34, 35 pass through the transfer curves 21, 22. The crossbeams 34, 35 shown in different return positions in the return stroke can be controlled so that the suction spiders 37 (37a, 37b) pivot about the crossbeam 34 during the horizontal and / or vertical movement thereof. The suction spiders 37 can thus be positioned in an inclined position in which they can be attached to the sheet metal part 16 held in a tilted position by the clipboard 18. During the resetting movement of the cross-beam 34, the suction spiders 37 are rotated into this position. The sheet metal part 16 is thus placed on the transfer curve 22 in the lower tool 8 without interference. Even when inserting the sheet metal part 16 into the press station 4 or when removing it from the press station 3, it can be brought into different tilting positions if necessary by pivoting the suction spiders 37.

The indicated rotary adjustments of the cross members are only examples. Due to the fact that the servomotors 62 can be controlled freely and the crossbars 33, 35 can be exchanged for those that each carry one or more swivel unit (s), various combinations are possible. Instead of the swivel units, non-swiveling suction spiders can also be coupled to the bases 49, 50, in the horizontal direction or are oriented in an inclined direction. The bases 49a, 50a illustrated in FIG. 3, with corresponding extensions of the holder 48a, 48a ', form a coupling arrangement which is provided with a locking device (not shown) for locking. The coupling arrangement in question is unlocked by a short-stroke movement, directed axially to the crossbar 34 and pivoting away of the locking bolt, after which the suction unit 37a, 37b can be removed. If necessary, the coupling arrangement can also be replaced by other connecting means, so that the suction unit in question 37a, 37a is firmly connected to the respective crossbar 34 (33, 35).

A transfer device 23 for a press system 1 has crossbeams 33, 34, 35, on each of which at least one suction unit 37a is held, which is pivotally mounted on the crossbeam 34. The suction unit 37a has a preferably electric drive, by means of which the pivoting movement can be matched to the transfer curve to be traversed (horizontal and vertical movement). If necessary, two or more suction units 37a, 37b can be arranged on a crossbar, which can be pivoted independently of one another. Retrofitting and retrofitting of existing cross members is possible by replacing previously used non-swiveling suction units with swiveling ones. Other changes to the mechanical structure of the transfer device 23 are not necessary.

Claims (13)

1. Transfer arrangement (23), in particular for the transfer of workpieces (14, 15, 16) between press stages (3, 4) in a predetermined transfer direction (T), with carrying and guiding means (24, 25) which extend essentially in the transfer direction (T) and which carry between one another crossmembers (33, 34, 35) which are equipped with gripper means (36, 37, 38) and which can be brought into and out of engagement with the workpieces (14, 15, 16), and with drive means (62, 63, 64, 61) which act on the gripper means and by which the gripper means (36, 37, 38) can be pivoted about an axis of rotation oriented transversely to the transfer direction (T), characterized in that at least one (34) of the crossmembers (33, 34, 35) carries a bearing arrangement (47), on which the gripper means (37) is mounted so as to be pivotable about the axis of rotation oriented transversely to the transfer direction (T), and in that this crossmember (34) carries the drive means (62, 63, 64, 61) by which the gripper means (37) can be pivoted.
2. Transfer arrangement according to Claim 1, characterized in that a coupling arrangement (49, 50) is provided, between the gripper means (37) and the crossmember (34) carrying the pivotable gripper means (37), on the said crossmember.
3. Transfer arrangement according to Claim 2, characterized in that the coupling arrangement (49, 50) is designed to be releasable as required.
4. Transfer arrangement according to Claim 1, characterized in that the crossmember (34) carrying the pivotable gripper means (37) is designed non-rotatably and is held non-rotatably on the end face.
5. Transfer arrangement according to Claim 1, characterized in that the bearing arrangement (47) is designed in such a way that the axis of rotation lies within the crossmember (34).
6. Transfer arrangement according to Claim 5, characterized in that the bearing arrangement (47) contains at least one bearing unit which includes two arcuate guide faces (52, 53) which are spaced from one another and lie on a common circle and on which the gripper means (37) are mounted by means of rollers (56, 57, 58, 59), and in that the drive means (62, 63, 64, 61) contains a geared motor (62, 63) which, driving via a toothed quadrant (61) connected to the gripper means (37), is connected to the said toothed quadrant.
7. Transfer arrangement according to Claim 1, characterized in that the drive means (62, 63, 64, 61) is arranged operatively between the crossmember (34) and the gripper means (37).
8. Transfer arrangement according to Claims 1 and 7, characterized in that the gripper means (37) and the drive means (62, 63, 64, 61) are designed as a unit removable from the crossmember.
9. Transfer arrangement according to Claim 1, characterized in that the gripper means (37) carried by the crossmember (34) have at least one first gripper unit (37a) and at least one further gripper unit (37b) which is pivotable independent of the first gripper unit (37a).
10. Transfer arrangement according to Claim 1, characterized in that the gripper means (37) carried by the crossmember (34) contains at least one gripper unit held non-rotatably on the crossmember (34).
11. Transfer arrangement according to Claim 1, characterized in that the gripper means (37) has vacuum-actuated sucker means (46).
12. Transfer arrangement according to Claim 1, characterized in that the crossmembers (33, 34, 35) are releasable from the carrying and guiding means (24, 25).
13. Transfer arrangement according to Claim 1, characterized in that the carrying and guiding means (24, 25) are running rails, on which trolleys (26, 27, 28, 29, 30, 31), to which the crossmembers (33, 34, 35) are releasably connected, are mounted so as to be movable in the transfer direction (T), the trolleys (26, 27, 28, 29, 30, 31) being assigned drive means for controlled movement in the transfer direction (T) and the running rails (24, 25) being assigned drive means, in order to raise and lower these.