EP0850710A1 - Flexible multiple axle transfer - Google Patents

Abstract

The transfer unit (41) is intended for workpieces to be transported along a predetermined route, in particular, along several successive workstations. It includes a cross beam (46) provided with a holding device (47) for holding and releasing work-pieces, a carrier mechanism (50) for the cross beam enabling the holding device to be moved along a predetermined transfer curve (K), and a drive system which can move the cross beam (46) in at least two mutually independent directions (T, V). Such a system incorporates two independently controllable drive units (61, 62). The unit is improved by the following facts: a) carrier mechanism (50) is made up of link mechanisms (50a, 50b) located between the drive system and the cross beam (46); b) the cross beam (46) at one end is held by the linkage mechanism (50a) which determines the position of this end in two specified directions (T, V); c) the cross beam at the other end is held by the linkage mechanism (50b) which analogously determines the position of that end in these two directions, as well as in a further direction oriented perpendicular to the former two. Also claimed is a corresponding multistation installation (in particular, a press for sheet-metal work) which is improved by the presence of at least one transfer unit (41).

Description

The invention relates to a transfer device for Transport of workpieces from a work station in a processing station following in the processing sequence. The invention also relates to a transfer system with such transfer devices and a machine tool, especially with a multi-station press such transfer facilities.

The transfer system picks up the workpiece and guides it to the next workstation in the processing sequence and put it there. Gripping or holding means of the The transfer system must then leave the workstation be brought out so as not to hit the workpiece colliding tool. The one in the transfer transfer movement to be carried out by the holding means depends on the specific conditions in relation to the Workpiece and tool dependent. Will the multi-station press or the other processing device retooling a new workpiece is usually the same Adjust transfer curve. In addition, the concrete ones Dimensions and parameters of the to be machined Workpieces at the time of conception and / or construction of the multi-station press not to the last Detail set. Therefore the transfer curves in the can be adjusted afterwards.

The transfer movement is usually a two-dimensional one Curve consisting of a stroke and a feed component is composed. It may also be required be to swivel the workpieces around transverse axes, if, for example, a different orientation in a drawing step have than in a subsequent press station. In many cases it is useful to choose between several Work stations define different transfer curves.

To use the multi-station press if necessary To be able to machine workpieces in successive Press stations around different axes differently are to be aligned, and in doing so, if possible no restrictions by the transfer facility a transfer facility with is possible many movement options with a minimal number of Drives to be desired. However, at the same time it is one sufficient positioning accuracy and one if possible high transfer speed to a high To enable working speed of the multi-station press.

From US-A-4 887 446 is a three-axis transfer trained transfer system known. Belong to this two are along the direction of flow through several press stations extending transfer rails. These are arranged on both sides of the tools. On the transfer rails The retention means provided are for temporary use Picking up the workpieces. The retention means are from held a longitudinal beam which is longitudinally displaceable on the Transfer rail stored and via electric linear drives is driven controlled in the longitudinal direction. Additional linear units are used to move the transfer rail in the vertical stroke direction as well as that Transfer rails towards and away from each other move (open / close).

This transfer device, which is for all workstations working in unison, only allows lifting, transporting and lowering the workpieces. No other positioning options are provided. In addition, the driving forces of each axis are from to apply the drives assigned to the relevant axis, which are on the other drives or Support the guides of the other axis directions.

DE 42 37 312 A1 describes a two-axis transfer known, between which is in the direction of flow extending transfer rails cross beams with suction spiders are arranged. The crossbeams lead one Transfer movement, in the course of which they move in the vertical direction and be moved in the direction of flow. A The workpieces are tilted about the transverse axis in so-called Clipboards between the press stations are arranged.

The clipboards claim a noteworthy Installation space, which affects the effort for the press system overall precipitates.

A transfer system is known from WO93 / 00185, whose features are the preamble of claim 1 form. The transfer system contains individual, between Transfer stations arranged at work stations. Each Transfer device leads transversely to the direction of the parts pass extending suction bridge along a programmable transfer curve. Two are used for this transfer drives holding the suction bridge at their ends. Each transfer drive demonstrates one vertically below extending extension on which by means of a Drive unit is telescopic in the stroke direction. To the Extension is also by means of a drive unit Lever mounted about a vertical axis, which over a connecting rod is connected to the end of the suction bridge.

The acceleration of the suction bridge in Reaction forces occurring in the flow or longitudinal direction are from the vertically telescopic carrier to record.

In addition, scissor and handlebar guides are from practice known to serve tools in space to lead.

Based on this, it is an object of the invention to to create versatile transfer device.

This task is done by a transfer facility solved according to claim 1.

In the transfer device according to the invention the holding means, for example suction cups, from a crossbar held up in turn at both ends by Handlebar gearbox is worn and guided. The handlebar gear have handlebar elements that are mainly on train or on pressure and not or only slightly on bending be charged. You're essentially stretched with an offset for space reasons is to be provided.

Both handlebar gears position the crossbar fixed in two directions with respect to the longitudinal extent the essentially elongated Crossbar are radial directions. This is one controlled parallel guidance possible. In addition sets a handlebar gearbox the position of the crossbar in one further direction, for example in the longitudinal direction of the crossbar firmly. This position can be fixed or be adjustable.

The handlebar elements grip the crossbar like this indicates that their position with respect to all degrees of freedom is defined. Is it a transfer device, for example with six degrees of freedom, are total at least six link elements are provided, consisting of three different directions and in three from each other spaced articulation points or points on the carrier means attack. By means of the drive units attached to the ends of the link elements remote from the carrier means can be articulated, the steering gear operated by the handlebar elements individually or together be moved synchronously or unsynchronously. A control unit coordinates these movements so that a desired one Transfer curve is obtained.

The maximum six possible degrees of freedom of the Holding means do not only allow a translation of the Workpiece but also tilting, turning and swiveling the same around all three spatial directions. So that's one Transfer facility created in the design the workpieces and tools have a high degree of freedom of movement allows. So the transfer system is also for possible ones suitable for future complicated tasks.

The forces acting on the crossbar as well their inertial forces are shared between the handlebar elements and the drive units so that each drive unit only a part of the to go through the Apply the required force or power to the transfer curve got to. It can be relative overall achieve great accelerations what the transfer times shortened.

If necessary, the transfer device can do less than six degrees of freedom, with the Handlebar elements, however, at least in two different Extend directions away from the support means and this at two articulation points located apart from each other carry. Even with such a system, they share loads and forces acting on the crossbar the handlebar elements and drive units.

The drive units are preferably each stored stationary. Each drive unit thus manages the Drives and managers directly in a base frame from. This results in a rigid mounting and guidance of the Carrier and thus even at high transfer speeds good positioning accuracy. The Handlebar elements can be made light and stiff.

The drive units are preferably linear drives, whose outputs each define an axial direction. Although these differ in principle from each other could result with corresponding axial directions, i.e. parallel directions of movement, the individual Outputs clear geometric relationships that the calculation of the individual control signals of the drive units facilitated by the control device.

The drive units are preferably electrical Drives where the rotary motion of a servo motor via appropriate gear means in a linear movement is implemented or in which the linear movement by Linear motors is generated directly.

A simple two-axis transfer results if the Handlebar gearboxes are designed so that the position the crossbeam is fixed with respect to its longitudinal direction, is not adjustable.

In all of the aforementioned embodiments, the Drive units when accelerating the holding means together and thus add up in their effect. This enables it with a processing device such as For example, a multi-station press that is used for the transfer reduce the required times and thus the work cycle to increase the multi-station press. It is it is also possible to schedule the individual press stations to work offset against each other, so that by the phase shift between successive ones Press or work stations have sufficient transfer time is made possible. Conversely, with a press circulation less time is reserved for the transfer, which means also the work cycle of the multi-station press can accelerate.

Fig. 1

eine Mehrstationenpresse mit zwischen einzelnen Arbeitsstationen angeordneten Transfereinrichtungen, in schematisierter und ausschnittsweiser Darstellung,

Fig. 2

die Mehrstationenpresse nach Fig. 1 in einer aufs äußerste schematisierten Seitenansicht,

Fig. 3

die Transfereinrichtung der Mehrstationenpresse nach den Fig. 1 und 2, in einer perspektivischen, schematisierten Ansicht,

Fig. 4

die Transfereinrichtung nach Fig. 3 in einer schematisierten Draufsicht, und

Fig. 5

die Kinematik der Transfereinrichtung nach den Fig. 3 und 4.

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

Fig. 1

a multi-station press with transfer devices arranged between individual work stations, in a schematic and partial representation,

Fig. 2

1 in an extremely schematic side view,

Fig. 3

the transfer device of the multi-station press according to FIGS. 1 and 2, in a perspective, schematic view,

Fig. 4

3 in a schematic plan view, and

Fig. 5

the kinematics of the transfer device according to FIGS. 3 and 4.

description

One illustrated schematically in FIGS. 1 and 2 Multi-station press 1 has several in a row arranged work or press stations 2, 3, 4, 5, 6 on, on sliding tables 8, 9, 10, 11, 12 dies 14, 15, 16, 17, 18 are held. These form sub-tools, which each have an upper tool 21, 22, 23, 24, 25 is assigned. This is in each case on a plunger 26, 27, 28, 29, 30 held, the one beyond shown eccentric drive or an articulated drive is moved up and down. The drive and the Tappets are supported by a not shown Press frame from which in Fig. 1 only schematically and exemplifies part of a stand 31 is.

The plungers 26 to 30 lead out of phase with one another an up and down movement. By the time and phase offset of the ram movement neighboring plunger is compared to in common mode working plungers achieve a better load distribution. Required flywheel masses can be significantly reduced and the multi-station press becomes a total lighter. There is also an at least partial weight balance the ram weights possible.

Between two neighboring workstations 2, 3; 3, 4; 4, 5; 5, 6 is a transfer device 41, 42, 43, 44 arranged along the workpieces a direction of travel T through the multi-station press 1 transport. The transfer devices 41 to 44 are identical to each other and below using the example of the transfer device 41. This has a crossbar 46 which is transverse to the Passage direction T extends and along a transfer curve K is to be moved. On the crossbar is one Suction spider 47 held so that the crossbar 46th together with the suction spider 47 a vacuum operated Holding agent forms.

The crossbar 46 is at both ends Joint units 48, 49 connected, each to one Handlebar gear 50 (50a, 50b) belong. The joint unit 48 is with the crossbar 46 via a hinge joint 51 connected, the hinge axis 52 with the direction of passage T matches. At the other end is the Crossbar 46 with the hinge unit 49 rigid or articulated. The steering gear 50a puts the Position of the crossbar 46 in the direction of T and in the vertical direction V. The steering gear 50b sets also the position of the crossbar 46 in the direction of passage T and in the vertical direction V and additionally in Transverse direction fixed.

The joint unit 48 is made up of a total of three handlebars or rods 53, 54, 55 carried. These are included one end each with a joint on the joint unit 48 stored, the at least one pivoting movement by one Axis 56 oriented transversely to the direction of travel T allowed. The joints of the rods 53, 54 have the Joint axis 56 together. The is spaced from it Rod 55 articulated to the joint unit 48. The hinge axis 57 of the corresponding joint is to the joint axis 56 parallel and spaced from this.

Each rod 53, 54, 55 is with its from the joint unit 48 remote ends each with a vertical oriented linear drive unit 61, 62, 63 connected. The linear drive units 61, 62, 63 each have one guided on guide rails 65 in the vertical direction Slide 67, 68, 69 on the one with the one in question Rod 53, 54, 55 with at least one transverse axis defining joint is connected.

A servo motor drives the slide 67 71, the rotational movement of which is not further illustrated Gear means, such as a toothed belt, a screw jack, a rack or the like, converted into a linear movement and on the Carriage 61 is transmitted. Accordingly, the Carriage 69 driven by a servo motor 72, the Rotary movement via a reduction gear 73 and one Toothed belt drive 74 or comparable gear means in a linear movement is implemented using a connecting rod 75 is transferred to the carriage 69. Another servo motor 77 is via a reduction gear 78 and a toothed belt 79 and a connecting rod 80 connected to the carriage 68. In addition to the swiveling movements around the transverse axes a total of six at the ends of the rods 53, 54, 55 existing joints still swiveling movements at right angles to it Directions, at least in a limited Allow swivel range.

All drive units 61, 62, 63 are stationary stored machine parts or elements, such as stands, Frame or the like, stored.

Are on the opposite joint unit 49 also rods 83, 84, 85 pivotable about several axes articulated, which belong to the steering gear section 50b. In addition to the pivoting movement about a transverse axis 58 also at least limited swiveling movements by one Vertical axis and / or a longitudinal axis possible.

At the other ends are the rods 83, 84, 85 with drive units 86, 87, 88 connected. These each point one vertically displaceable on guide rails 91 mounted carriage 92, 93, 94 on. The carriage 92 is driven by a servo motor 96, which via a Rotary movement into a linear movement gear 97 is connected to the carriage 92. Is accordingly a servo motor 98 with such a gear means 99 connected to the carriage 93. To drive the slide 94 Serves a servo motor 101, which rotates about its gear means 102 converting into a linear movement this is connected.

5 shows the kinematics of the transfer device 41. For example becomes a movement of the crossbar 46 reached in the direction of travel T by the carriage 69 and 92 slightly down and the rest of the sledges be moved vertically upwards. Procedure of Slide 67 up or down results in a rotation of the crossbar 46 about its transverse axis. For Adjustment of the crossbar in the vertical direction all slides 67, 68, 69; 92, 93, 94 up or down adjusted below. A swiveling or tilting of the crossbar 46 by the one defined by the direction of passage T. Axis is adjusted by different adjustment of the slide 67, 68, 69 and the carriage 92, 93, 94 reached. Overall, it can be seen that the three differ Spatial directions away from the joint unit 49 extending rods 83, 84, 85 the position of the joint unit 49 with respect to the translational axes T, V, Q clearly define. In contrast, the struts 53, 54, 55 the corresponding swivel positions.

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

The movement of the press rams 26 to 30 is like this coordinated that the in the direction of flow tappets downstream of part flow the preceding (upstream) Tappets lag by a time offset, which in the essentially corresponds to the time that each transfer device 41 to 44 required to the crossbar 46 of one workstation to the next workstation to pan. For example, the top tool begins 21 move upward, the servomotors 71, 72, 77; 96, 98, 101 controlled so that the crossbar 46 swings into the opened tool and the workpiece records. While the crossbar 46 by appropriate Controls of the servomotors 71, 72, 77; 96, 98, 101 now on the transfer curve K towards the next one Press station 3 is pivoted too, has its press ram 27 go through its bottom dead center and opens the tool so that after removing the workpiece the transfer device 42 removes the workpiece from the transfer device 41 can be inserted.

The control device not shown controls the servomotors 71, 72, 77; 96, 98, 101 so that the desired transfer curve K is obtained. Swiveling movements of the workpiece around a transverse axis or other more complicated positioning tasks can be done without more to be done during the transfer. As Fig. 5 shows, the transfer device has six degrees of freedom on. If necessary, the number of degrees of freedom can be reduced, the transfer device in question then simplified accordingly. In the simplest embodiment are only two linear axes available, each via pairs of rods on the Attack crossbar 46. This allows two-dimensional Achieve transfer curves K.

In an embodiment not further illustrated the handlebar elements are adjustable in length trained and with their respective, from the Transverse crossbar end fixed over a joint stored. The drive units are in the handlebar elements integrated.

However, it is also possible to drive units like this train that their drives on an arcuate Are guided. The drives are then crank motors, for example Eccentric drives operated by servomotors will.

Simplified embodiments can be reduced Have number of drives. E.g. can they Bars 53 and 55 both on carriage 67 or 69 be stored when there is no pivoting of the cross-beam is required. It is also possible to attach the rod 83 the carriage of rod 84 or 85 if none Adjustment in the transverse direction Q is required.

One provided in particular for multi-station presses 1 Transfer device 41 has one of several Bars 53, 54, 55; 83, 84, 85 worn restraint (46, 47) on that of the rods 53, 54, 55; 83, 84, 85 is pivotable and positionable in the room. The poles 53, 54, 55; 83, 84, 85 are preferably with linear drive devices 61, 62, 63; 86, 87, 88 connected, the thus act together on the holding means 46, 47. With a six degrees of positioning freedom Embodiment grab three of the rods 53, 54, 55; 83, 84, 85 at a first hinge point 49 of the retaining means 46, 47. Define with their other ends these rods 83, 84, 85 a triangle. Of the remaining three rods 53, 54, 55 grip two 53, 54 on one another hinge point 56 and a third 55 on one of them remote hinge point 57, with the other two A triangle again defines articulation points 49, 56. A such a transfer device 41 enables in addition to the simple one Workpiece transfer complicated positioning tasks.

Claims (10)

Transfer device (41) for workpieces to be transported in a predetermined way, in particular for the transport of workpieces along several successive work stations (2, 3, 4, 5, 6), with a holding means (47) which serves to take up and release workpieces in a controlled manner, with a crossbar (46) which carries the holding means (47), and with a carrier means (50) which carries the cross-beam (46) and leads on a predetermined transfer curve (K), with a drive means by means of which the crossbar (46) can be driven in at least two mutually independent directions (V, T) and which has at least one first and a second drive unit (61, 62) which can be controlled independently of one another,
characterized, that the carrier means (50) is formed by a first and a second link mechanism (50a, 50b), which are each arranged between the drive means and the crossbar (46),
wherein the crossbar (46) is supported at one end by the first link mechanism (50a) which defines the position of one end of the crossbar (46) in two given directions (T, V), and
the crossbar (46) is held at its other end by the second link mechanism (50b) which also determines the position of the other end of the crossbar (46) in the two given directions as well as in a further direction (Q). Transfer device according to claim 1, characterized characterized in that each handlebar gear (50a, 50b) at least two mainly under tension and pressure Handlebar elements (53, 54; 183, 84, 85), which in at least two different directions extend from the crossbar (46) and each with a first end via an articulation device (48) are connected to the crossbar (47), each Handlebar element (53, 54) a drive unit (61, 62) is assigned, by means of which the position of the second, from the first end of the end of the handlebar element (53, 54) is specifically adjustable. Transfer device according to claim 1, characterized characterized in that each link element (53, 54) its second end with the drive unit assigned to it (61, 63) is connected via a joint. Transfer device according to claim 1, characterized characterized in that the handlebar elements (83, 84, 85) of the Handlebar gear (50b) at one end of the crossbar (46) at a pivot point (A) and at the other end of the Crossbar (46) on two spaced apart Articulation points (B, C) in connection with the crossbar (46) stand so that the articulation points (A, B, C) Define triangle, at one of the articulation points (A) three handlebar elements (83, 84, 85), on another of the Articulation points (B) two handlebar elements (53, 54) and on the remaining one of the articulation points (C) a handlebar element (55) are connected to the crossbar (46). Transfer device according to claim 1, characterized characterized in that the drive units (61, 62) each are stationary. Transfer device according to claim 5, characterized in that the drive units (61, 62) are each linear units, the drives (67, 68) of which perform a linear movement which is dependent on an input signal, and that the linear units have mutually parallel working directions (V) and are arranged at a distance from one another transversely to their working direction. Transfer device according to claim 6, characterized characterized in that the drive units (61, 62) are electrical Are direct drives. Processing device (1) for the sequential processing of workpieces in several steps, in particular suction press for processing sheet metal parts, with a plurality of work stations (2, 3, 4, 5, 6) arranged one behind the other, which the workpieces have to pass through successively, and with at least one transfer device (41) according to one or more of Claims 1 to 7. Processing device according to claim 8, characterized characterized that between two successive Workstations (2, 3) a transfer device (41) is arranged independently of other transfer devices (42, 43) of the processing device (1) is controllable. Processing device according to claim 8, characterized characterized in that the work stations (2, 3, 4, 5, 6) the processing device (1) to each other in time work offset.

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