EP0850709B1 - Transfer device and multistage press - Google Patents

Description

The invention relates to a transfer device for Transfer of workpieces from a work station to a processing station following in the processing sequence as well as one from such transfer facilities built transfer system and a multi-station press with such transfer facilities.

With multi-station presses or other systems with several successive workstations is one Transfer system required to transport the workpieces. The transfer system usually needs the workpiece seize, lead out of the respective workstation, transport to the next workstation and in put them down. Then appropriate gripper and Holding devices of the transfer system so far be brought out to the workstation that they are not collide with the tool acting on the workpiece.

From US-A-4 887 446 is a three-axis transfer system known for transfer presses. To that Transfer system belong two along the workpiece pass direction over several press stations Transfer rails. Wear the transfer rails Retaining means for the workpieces. The restraint are held on a side member on the transfer rail mounted longitudinally and via an electric Linear drive can be driven in the longitudinal direction. Additional linear units serve the transfer rails moving towards and away from each other as well raise and lower synchronously.

The longitudinal drive is supported here on an intermediate carrier which in turn is in the transverse direction (opening, Closing) and in the vertical direction (lifting, lowering) is moving. The driving forces of each axis are alone of the drives assigned to the relevant axis apply while the other drives or guides are loaded with these forces in the lateral direction. In addition, everyone works with this transfer device Holding means inevitably in common.

A transfer press is known from DE 42 37 312 A1 known a two-axis transfer. For transporting workpieces are used for grippers held on cross beams. The Crossbars are at their ends on transfer rails held to form the vehicle for this. The transfer rails are of corresponding drive units only to move in the longitudinal and vertical directions. If necessary, clipboards can be placed between the press stages be provided, the workpieces temporarily record and realign them if necessary, e.g. rotate about its transverse axis as required when the workpieces in successive press stages are to be processed at different angles.

In this two-axis transfer are the drive devices Effectively arranged one behind the other, i.e. the output of a drive device is full of Mass of the downstream drive device loaded.

WO93 / 00185 discloses a transfer system with suction bridges, the ends of each on an electrical Drive unit are held and the characteristics of the The preamble of claim 1 form. Every drive unit is designed as a lifting and transfer unit and has a downward extending, vertical direction telescopic arm. At the bottom is a by means of a servomotor around a vertical axis rotatable lever arranged. This is over a connecting rod connected to one end of a cross-member carrying a sucker. The lever and the connecting rod carry the crossbar and thus form a vehicle for them.

The acceleration of the suction bridge in the direction of travel occurring acceleration forces must from the downward-extending, telescopic Arm.

In addition, from practice are scissors or Rod arrangements known, with which, for example, tools complicated tracks can be run.

In addition, the transfer curves are from the processed Workpieces are dependent and have to be changed adapted to a workpiece series and when changing tools become. In addition, the transfer facility for the Workpiece transfer takes as little time as possible.

This results in the basis of the invention Task, a flexible transfer device to create the high speed of work of enables you to operate workstations. Besides, is it is an object of the invention to provide a multi-station press create that has a high working speed and in a simple way on different workpieces is convertible.

These tasks are performed by a transfer facility according to claim 1 or a multi-station press according to claim 12 solved.

The transfer device points in in its simplest form a crossbar with at least a retention agent. The crossbar is on both ends carried by handlebar gears, the simplest Case of mainly stressed under tension and pressure Handlebars, such as rods, are formed. Any handlebar gear is, for example, two spaced apart Drive units connected. The drive units are preferably linear axes that are at a distance are arranged parallel to each other. However, you can they can also be integrated into the handlebar means. The Connection points between the holding means and the Handlebars and the connection points between the handlebars and the drive units define a triangle or trapezoid. This can be done by coordinated control of the individual Drive units a defined movement of the crossbar both in one by the direction of the drives Drive units set direction as well as transversely to be achieved. Within a given maximum range almost any transfer curve can be created to adjust.

For the crossbeam, the two add up Handlebar transmissions given driving forces so that the to accelerate, brake, raise and lower the Crosshead required force from all drive units is applied together. In contrast to known ones Transfer devices add up the forces the drive units on the retaining means accordingly the angular relationships defined by the handlebars. In addition, the reaction forces of each drive unit supported directly on a base frame, which is a high Rigidity and precise guidance of the holding means enables. On the other hand, the one assigned to the vertical direction Drive unit in the known devices the reaction forces of the drive unit for the Record lengthways.

The handlebars close when they are straight bars are formed with each other a non-zero Angle on. The handlebars are with the drive units and the retaining means preferably via hinge joints connected, which is preferably only the rotation around allow a hinge axis. All hinge axes are aligned essentially parallel to each other. The This gives the restraint its lateral guidance. It is within the required accuracy in a Level guided so that the achievable transfer curve is two-dimensional. In an advantageous embodiment are both linkages effective with each other same, i.e. For example, mirror-symmetrical to each other trained and arranged. The drive units of the Handlebar gearboxes can then be combined in pairs be, whereby the transfer device with only needs two drive units.

Although the drive units in principle also in Work in the direction of the respective handlebar means or in this could be integrated, it is usually also advantageous execute these as separate linear units, which usually results in improved leadership. The Linear units can be, for example, hydraulic or electrical Be drives. As electrical drive units servomotors can be provided, which with corresponding Geared, like a screw jack, one Toothed belt gear or a rack, a corresponding Generate linear motion. Alternatively, electrical Direct drives, e.g. asynchronous or synchronous working linear motors.

Parallel working directions of the linear drives lead to clear geometric relationships, see above that a calculation to be performed by a control unit the control signals of the individual drive units to generate a desired transfer curve with reasonable Effort can be done. Will be here Accepted somewhat higher computing effort than Drive units also eccentric actuated by servomotors or crank drives are used, their output is guided on an arcuate path.

A third link means with one of the above Handlebar means forms a parallelogram, can be provided to ensure that the retention means the transfer curve with uniform angular orientation goes through. Alternatively or additionally, this can be done Holding device with its own swivel drive be a twist with respect to the crossbar causes.

A parallelogram handlebar can be used if necessary also provided with its own drive device to be able to pivot the holding means in a targeted manner bring about.

If larger workpieces are used with the transfer device Each handlebar means contains to be transported two mutually parallel links, their respective ends with one extending between the two links Crossbar is connected. Every driver is on his each other end guided on a linear axis. Both linear axes are parallel to each other and are operated synchronously. The connection of both handlebars to one only linear axis is via a corresponding cross member possible.

Corresponding advantages apply equally to one Multi-station press, the at least one according to the invention Contains transfer device. The transfer curve for chaining the successive press stages can with the transfer device can be set flexibly, being through the common action of the drive units when accelerating and braking the holding means fast transfer and therefore a high number of cycles Press stages can be achieved.

Clipboards can generally be dispensed with become. If necessary, you can do this on the holding means Swivel units are provided.

It is advantageous between two successive ones Press stations a separate transfer facility arranged so that the multi-station press has several separately controllable transfer devices. This allows the transfer curves between individual Press stations are run through at different times and it becomes possible to schedule the individual press stages to make it work staggered. For example, a workpiece is out taken from a press station and begins to close their tool again is that subsequent tool still opening while the transfer device moves the workpiece towards it emotional. The offset working method of the individual press stages leads to a more even decrease in power, so that the required flywheel mass of the main press drive can be significantly reduced. Besides, it will due to the staggered work in succession Press stages possible, the workpiece transfer at least partly before or after work stored work stations so that the Share of transfer time in total cycle time clearly sinks. This also allows the number of cycles to be increased without that the transfer speed would have to be increased.

If necessary, however, several transfer devices, between different press levels stand, combined into a transfer group be connected to each other via transfer rails are.

Fig. 1

eine Mehrstationenpresse mit Zweiachs-Transfervorrichtungen zwischen einzelnen Pressenstufen, in schematisierter, ausschnittsweiser Perspektivdarstellung,

Fig. 2

die Mehrstationenpresse nach Fig. 1 in einer schematisierten Seitenansicht,

Fig. 3

die Zweiachstransfervorrichtung der Mehrstationenpresse nach den Fig. 1 und 2, in perspektivischer Darstellung,

Fig. 4

die Transfereinrichtung nach Fig. 3 in Draufsicht,

Fig. 5

eine abgewandelte Ausführungsform des Zweiachstransfers für eine Transferpresse nach den Fig. 1 und 2, in ausschnittsweiser, perspektivischer Darstellung, und

Fig. 6

die Transfereinrichtung nach Fig. 5 in einer schematisierten Seitenansicht, unter Veranschaulichung unterschiedlicher Bahnpunkte einer durchfahrenen Transferkurve.

Fig. 7

eine alternative Ausführungsform der Transfereinrichtung mit einem Zahnriemenmodul, der in einen Lenker integriert ist und die Rotationslage der Quertraverse definiert, in perspektivischer Darstellung, und

Fig. 8

die Transfereinrichtung nach Fig. 7, in schematisierter Schnittdarstellung.

Exemplary embodiments of the invention are shown in the drawing. Show it:

Fig. 1

a multi-station press with two-axis transfer devices between individual press stages, in a schematic, partial perspective view,

Fig. 2

1 in a schematic side view,

Fig. 3

1 and 2, in a perspective view, the two-axis transfer device of the multi-station press,

Fig. 4

3 in top view,

Fig. 5

a modified embodiment of the two-axis transfer for a transfer press according to FIGS. 1 and 2, in a fragmentary, perspective view, and

Fig. 6

5 in a schematic side view, illustrating different path points of a transfer curve traveled through.

Fig. 7

an alternative embodiment of the transfer device with a toothed belt module, which is integrated in a handlebar and defines the rotational position of the crossbar, in a perspective view, and

Fig. 8

the transfer device of FIG. 7, in a schematic sectional view.

description

In Fig. 1, a multi-station press 1 is based their workstations 2, 3, 4, 5, 6 indicated. Each Workstation 2, 3, 4, 5, 6 has a table 7, 8, 9, 10, 11 on the top of a sliding table 12, 13, 14, 15, 16 carries (Fig. 2). On the sliding tables 12 to 16 belong to a particular tool Joints or lower tools 21, 22, 23, 24, 25 arranged. They are arranged on plungers 27, 28, 29, 30, 31 Upper tools 32, 33, 34, 35, 36 assigned to the Tappets are moved up and down. Serves as a drive one eccentric or one articulated drive each. The eccentric (Drives) of all workstations 2 to 6 are from a common wave, not shown driven.

Workstations 2 through 6 are related to one Passage direction T arranged one behind the other and by means of a transfer system 40 chained together, the by separate transfer devices 41, 42, 43, 44 is formed. The transfer devices are 41 to 44 structurally identical to each other; the description of the Transfer device 41 applies accordingly to everyone other. For reference, the parts and elements of the Transfer devices 42 to 44 with the same, for Differentiation each with a letter index Reference numerals labeled as the transfer device 41.

The transfer device 41 is between the work stations 2 and 3 arranged. It has a crossbar 46, which is to be moved along a transfer curve K. The crossbar 46 carries two suction spiders 47 and thus forms a holding means for the workpieces. Along the transfer curve K is the crossbar 46 both to the lower tool 21 as well as to the next one Lower tool 22 movable.

3 and 4 is transverse to the direction of transfer T extending crossbar on both of them Ends 51, 52 connected to joint units 53, 54. Two form links 57, 58 connected to the articulation unit 53 together a steering gear 59, which is used to guide the Crossbar 46 serves at one end. The handlebars 57, 58 which is symmetrical with respect to a vertical longitudinal median plane trained transfer device 41 are on the Joint unit 53 with one end each with the same Hinge axis pivoted. With her from the ends of the joint unit 53 are the links 57, 58 each with a vertically displaceable Carriage 61, 62 connected.

To support the carriage 61, 62 serve on the Press stands 63 provided guide rails 65, 66. The slides 61, 62 are connected by connecting rods 67, 68 connected with linear units 69, 70 and in lifting or Vertical direction V adjustable. To the linear units 69, 70 include servomotors provided with gears 71, 72 73, 74 by a not shown Control unit are guided on the basis of position signals. To convert the servomotors 73, 74 and Gear 71, 72 generated linear movement serve timing belts 75 in one place with the respective connecting rod 67, 68 are connected. The sledges 61, 62 and those intended to guide and drive them Elements form drive units 77, 78, which correspond the desired transfer curve K can be controlled.

The articulation unit 54 is mirror-symmetrical to this connected via hinges to links 81, 82 which are parallel to each other and a steering gear 83 form. On their respective joint unit 54 far end are the handlebars 81; 82 articulated with Carriage 84, 85 connected to the press stand 64th are linearly movable up and down. The sledge 84, 85 form in conjunction with linear units 86, 87 and whose servomotors 86 ', 87' drive units 88, 89 for a common further axis V.

On the slides 62, 85 are 58, 82 to the handlebars parallel auxiliary links 91, 92 mounted with their respective other end with the joint unit 53, 54 are connected. The handlebar 58 and the auxiliary link 91 form a parallelogram to define the Position of the crossbar 46 with respect to the transverse axis. The same applies to the link 82 and the auxiliary link 92.

The multi-station press 1 described so far works as follows:

As shown in Fig. 2, the plungers move 27 to 31 of the multi-station press 1 with a mutual Phase shift up and down. The movement of the transfer facilities 41 to 44 is coordinated so that the Cross members 46 with the suction spiders 47 each outside the tools are in place when they are closed are. E.g. has that in workstation 2 Upper tool 32 is lifted from lower tool 21 and the plunger 27 moves upwards. To remove the Workpiece from the lower tool 21 becomes the crossbar 46 of the transfer device 41 into the opening Tool driven. For this purpose, the only in Fig. 2 linear drive units indicated by dashed lines 77, 78; 88, 89 controlled synchronously with each other so that the cross member carried by the linkages 59, 83 46 is moved along the transfer curve K.

During the transfer device 41 the workpiece has taken from the lower tool 21, the adjacent one Ram 28 pass through its bottom dead center and lifts the upper tool 33 from the lower tool 22. With the Transfer device 41 is activated by appropriate control the first drive units 77, 88 and the second Drive units 78, 89 a movement of the handlebar pairs 57, 81; 58, 82 and the cross member carried by them 46 causes, whereby the workpiece on the lower tool 22 is filed. After loosening the workpiece the runs Cross member 46 back, the tool 22, 33 closes.

The transfer devices 42 to 44 of the following Workstations 3 to 6 work accordingly. The Phase shift between the individual work stations 2 is dimensioned so that the with respect to the direction of passage T downstream ram upstream preceding ram by the transport time between the tools the in between arranged transfer device lags.

The transfer devices 41 to 44 can, depending on Control of their drive units 77, 78; 88, 89 different Go through transfer curves and onto them Adapted to different workpieces and tools become. In the event of malfunction or failure of a transfer device 41 to 44 there is only a risk of damage for the failed transfer facility. The other transfer facilities are not damaged, so that the damage is limited in the event of an accident remains.

A modified transfer device 41 'is shown in FIG Figure 5 illustrates. So much for the transfer facility 41 'with the transfer device described above 41 matches, reference is made to the description thereof. Without reference again, the same reference numerals are used based on. The difference is that instead of the parallelogram guide an auxiliary link 91 ' is provided, which has one end on the joint unit 53 and with its other end to a third drive unit 94 is articulated. This defines a third V axis parallel to that of the drive units 77, 78 defined axes V is aligned. While the Handlebars 57, 58 with a common pivot axis on the joint unit 53 are articulated, the articulation point of the Handlebar 91 'spaced therefrom. So that the crossbar 46, as is apparent from Fig. 6, by appropriate targeted control of the drive units 77, 78, 94 be pivoted in a defined manner.

The transfer device 41 is in total in FIG. 6 three different positions I, II and III (from right to left), in which the Crossbar 46 three different positions on the Transfer curve K takes. The associated slide positions the linear units are also with I, II, III designated.

Instead of the third drive unit 94 can targeted rotation of the suction spider 47 in the transfer device 41 on the crossbar 46 a rotating unit can be arranged which the suction spider 47 with respect to the crossbar 46 pivots defined. Regardless of whether the suction spider 47 is pivotable or is pivotally attached to the crossbar 46, clutch units 96 can serve to suck the spiders 47 when changing tools or for maintenance purposes to swap.

Finally, it is possible to change the right and left side linear drives of the transfer device 41 different to control, for example between Bearing units 53, 54 and the crossbar 46 each additional hinge joint is to be provided, the Hinge axis points, for example, in the transfer direction T. Thereby the crossbar 46 is tilted by one in the transfer direction T lying longitudinal axis possible.

Be additional joints and if necessary Length compensation provided on the crossbar 46 can with opposite control of the right and left side Linear units 69, 70; 86, 87 a pivoting of the Crossbar 46 can be reached about a vertical axis, which increases the flexibility of the drive. The Linear units 69, 70; 86, 87 can also if necessary be provided at the tables 7, 8.

A modified embodiment of the one described above Two-axis transfer device is shown in FIGS. 7 and 8 can be seen, but without a new description same reference numerals as in the above embodiments are used. The description applies corresponding. The difference is instead of the auxiliary link 92 a toothed belt drive 101 is arranged in or on the link 58, which determines the rotational position of the crossbar 46. This is rotatably connected to a toothed belt pulley 102, over which a toothed belt 103 is guided. In which Carriage 62 is toothed belt 103 via a toothed belt pulley 104 performed, the fixed with the sled or with an actuator is connected. The diameter of the Timing belt pulleys 102, 104 are preferably the same, but can also be different.

For multi-station presses 1 in particular Transfer device 41 provided between two Workstations 2, 3 is arranged. The transfer facility 41 has a direction transverse to a transfer direction T extending suction bridge 46, 47, which means two handlebar gears 59, 83 synchronously at their ends is guided along a predetermined transfer curve K. The link mechanism 59, 83 are by the end with the Crossbar 46 connected links 57, 58; 81, 82 or Rods formed on their respective crossbars 46 remote end at preferably vertical aligned linear axes 69, 70; 86, 87 are held the links 57, 81 and 58, 82 each in pairs Include the same angle with each other. Through targeted Driving the linear axes 69, 70; 86, 87 can in Frame of the range of the transfer device 41 almost any transfer curves K can be traversed. All Linear axes are supported directly on a stationary one Frame 63, 64 off, which ensures high rigidity and Precision is achieved even at high accelerations.

Claims (14)

1. Transfer arrangement (41) for workpieces which are to be transported on a predetermined path, in particular for transporting workpieces along a plurality of successive work stations (2, 3, 4, 5, 6), having a crossmember (46) which is provided with at least one securing means (47) which serves for receiving and releasing workpieces in a controlled manner,

   having a carrier means . (59, 83) on which the crossmember (46) is retained at both ends and by which the securing means (47) is guided over a closed transfer curve (K), and

   having a drive means which acts on the carrier means (59, 83), by which the crossmember (46) can be driven in two independent directions (V, T) and which has, for each crossmember end, at least a first and second drive unit (77, 78, 88, 89), which can be activated independently of one another, it being the case that the carrier means comprises a first guide-rod mechanism (59), which is connected to one end of the crossmember (46), and a second guide-rod mechanism (83), which is connected to the other end of the crossmember (46), and

   the crossmember (46) is borne by the guide-rod mechanisms (59, 83),

   characterized in that the first guide-rod mechanism (59) comprises at least two (guide) rods (57, 58), which are each connected at the ends to the crossmember (46) and a drive unit, and in that the second guide-rod mechanism (83) comprises at least two (guide) rods (81, 82), which are each connected at the ends to the crossmember (46) and a drive unit, and in that the crossmember is driven synchronously at its two ends by the drive units (77, 78, 88, 89), via the guide-rod mechanisms (59, 83).
2. Transfer arrangement according to Claim 1,
   characterized in that each guide-rod mechanism (59, 83) contains at least two guide rods (57, 58; 81, 82) which are subjected essentially to tensile and compressive loading and enclose an angle other than zero with one another, and in that the guide-rod mechanisms (59, 83) are functionally of the same design as one another.
3. Transfer arrangement according to Claim 2,
   characterized in that the drive units (77, 78; 88, 89) are connected in an articulated manner to the guide rods (57, 58; 81, 82), and the guide rods (57, 58; 81, 82) are connected in an articulated manner to the crossmember (46), via hinge articulations, of which the hinge pins are aligned essentially parallel to one another.
4. Transfer arrangement according to Claim 1,
   characterized in that the drive units (77, 78; 88, 89) are linear units (69, 70; 86, 87) in each case, of which the outputs execute a defined linear movement dependent on an input signal, and in that the first and the second linear unit (69, 70; 86, 87) are spaced apart from one another and have working directions which are essentially parallel to one another.
5. Transfer arrangement according to Claim 4,
   characterized in that the drive units (77, 78; 88, 89) are electric direct drives.
6. Transfer arrangement according to Claim 1,
   characterized in that the guide-rod mechanism (59, 83) comprises at least a third guide rod (91'), which is connected to a third drive unit (94) at one end, and to the crossmember (46) at its other end, by an articulation which is spaced apart from the articulations of the first and second guide-rod mechanisms (59, 83), these latter articulations defining a common pivot axis.
7. Transfer arrangement according to Claim 1,
   characterized in that at least one of the guide rods (57, 58) is part of a parallelogram linkage.
8. Transfer arrangement according to Claim 2,
   characterized in that each guide rod (57, 58) of one guide-rod mechanism (59) is guided parallel to, and at a distance from, in each case one guide rod (81, 82) of the other guide-rod mechanism (83).
9. Transfer arrangement according to Claim 1,
   characterized in that, for the guidance of the crossmember (46), at least one guide rod (58) is provided with a drawing-in mechanism (101), preferably a toothed-belt mechanism, via which the crossmember (46) is connected to an element (104) which predetermines its rotary position.
10. Transfer arrangement according to Claim 9,
    characterized in that the element (104) is retained in a non-rotatable manner.
11. Transfer arrangement according to Claim 9,
    characterized in that the element (104) is retained on the output of a drive arrangement.
12. Multi-station press for successively processing workpieces in a number of steps, in particular suction press for processing sheet-metal parts,

    having a plurality of press stages (2, 3, 4, 5, 6) which are arranged one behind the other and which the workpieces have to pass through successively, and

    having at least one transfer arrangement (41) according to one or more of Patent Claims 1 to 11.
13. Multi-station press according to Claim 12,
    characterized in that a transfer arrangement (41, 42, 43, 44) is arranged in each case between two successive press stations (2, 3; 3, 4; 4, 5; 5, 6), it being possible for said transfer arrangements to be activated separately.
14. Multi-station press according to Claim 13,
    characterized in that the transfer arrangements (41, 42, 43, 44) are activated at discrete points in time.

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