EP2091675B1 - Transfer device for a press - Google Patents

Description

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

State of the art

A transport device for transporting workpieces in a transfer press usually consists of two in the transport direction of the workpieces extending gripper rails, which perform an additional transverse movement in addition to the longitudinal and lifting movement, said gripper elements are provided on the gripper rails. To drive these gripper rails used in recent times different electrical drives, which have almost completely replaced the previously customary mechanical, coupled to the press drive drives.

After DE 195 06 079 A1 a device for transferring workpieces through a sequence of processing stations of a press, a simulator or the like is known, which has two parallel spaced apart, extending in the transport direction transport rails. On the transport rails receiving devices for the workpieces to be transported are arranged. The transport rails are in total by means of paired linear motors in the vertical direction and horizontally toward each other to move. The drive means for the movements in the three axes of movement are designed as paired linear motors, wherein the opposite with respect to the center axis of the press linear motors are controlled synchronously. The disadvantage of this solution are the large masses of moving parts. In particular, the drives of the individual axes of movement are arranged one above the other and must therefore be moved during the transport movement. This has a negative effect on the dynamics of the overall system. Another disadvantage is that the linear motors used are only partially suitable for use in forming machines because particles are attracted by a magnetic attraction and thus contaminate the running surfaces of the linear drives together with other dirt particles. This results in increased maintenance. Through the use of linear guides also disadvantages such as closure of the guides or contamination of the system by the lubrication of the guides must be taken into account. The lubrication lines must be provided constructively.

The generic DE 100 12 022 A1 already meets these disadvantages. It is disclosed a transfer drive, the weitgehenst waived maintenance-intensive guides for the individual movement elements. Proposed is a drive, which consists of movable link rods in a hanging arrangement. By using a three-dimensional drive a kind of "multi-point suspension" is created, that is, the gripper rails are suspended in all three axes of movement defined hinges, so that can be dispensed with conventional guides. It is advantageous that all joint rods and push rods are arranged above the transport plane of the workpieces, so that the tool room is very accessible and no disturbing ground devices are present. In particular, when using conveyor belts or storage stations, this has an advantageous effect.

A disadvantage of this arrangement is that the structural arrangement of the drives and the joint rods takes up a lot of space. In particular, the motion transmission for the opening and closing movement of the gripper rails is transmitted via a very bulky mechanism of hinges and link rods. This has the consequence that the transfer drive described above has to be mounted completely outside the stand in the direction of passage. As a result, the gripper rails must be so long that they protrude from both sides of the stator areas. This in turn means a large mass, which must be moved during the transport movement and thus a deterioration of the dynamics compared to the use of shorter gripper rails. By the suspension of the gripper rails outside the press stand, the support distance is relatively large, which has a large deflection of the gripper rails result. To reduce the deflection, the gripper rails must be designed with larger wall thicknesses. This in turn has a negative impact on dynamics.

Another disadvantage resulting from the large space requirement of the transfer drive described is that for some applications in which the customer only a limited space is available, this transfer can not be used.

Task and advantage of the invention

The invention is based on the object starting from the above-described prior art to develop a transfer drive in which the gripper rails are held by link rods and driven by servo motors and in which the drive means and the motion transfer means are largely arranged in the stand area. With a minimum of moving parts of the transfer drive according to the invention should also be made compact and thus inexpensive. This object is achieved starting from a press with a transfer device according to the preamble of claim 1 by the characterizing features of claim 1. In the dependent claims advantageous refinements and improvements of the main claim transfer device are realized.

The invention is based on the core idea of the motion transmission means, which act between the drives and the gripper rails to be arranged so that they mostly find space between the stands. In this case, no linear guides are used, but only joints which are characterized by low friction losses by a higher efficiency. In addition, joints can be lubricated and sealed better.

Despite the compact design of the press according to the invention with the transfer device in addition to the transport functions and all other functions as known from the prior art for a gripper transfer device, such as gripper rail width adjustment or tool change functions, feasible.

The transfer device of the press according to the invention is mounted on two trusses, which are attached to the respective pair of stands. On these traverses, the drives are mounted adjustable transversely to the direction of passage to allow a width adjustment of the gripper rail. The advancing movement, the lifting stroke movement and the opening / closing movement are generated by the fact that articulated rods or pairs of connecting rods are mounted spherically on the gripper rails. The opposite ends of the link rods are in turn mounted spherically on levers, which are rotatably connected to the respective drives.

An essential feature of the transfer device of the press according to the invention is the arrangement of the opening / closing movement strand. As a result of the abovementioned task of placing the motion transmission means in the stand area, it is no longer possible, as is known in the prior art, to move the gripper rail from the outside and to initiate a movement with suitable lever mechanisms.

In the transfer device of the press according to the invention, therefore, the drive trains for the opening / closing movements are arranged centrally between the gripper rails, symmetrical to the machine center line. For each gripper rail end, a drive train is preferably provided. Also, the drive unit for the opening / closing movement, as well as the drive units for the feed and the lifting stroke on a traverse, mounted transversely to the direction of passage adjustable or movable. Due to the space-saving arrangement in the stator area is the transfer device according to the invention in principle also suitable for use in multi-ram presses.

Further details and advantages of the invention will become apparent from the following description of exemplary embodiments in conjunction with the description of the figures.

Figur 1

Presse mit Transfervorrichtung in einer Seitenansicht

Figur 2

Transfervorrichtung in einer Draufsicht

Figur 3

Schnittdarstellung der Transfervorrichtung in Durchlaufrichtung

Figur 4

Mehrstößelpresse mit Transfervorrichtung in einer Seitenansicht

Figur 5

Schnittdarstellung in Durchlaufrichtung

Show it:

FIG. 1

Press with transfer device in a side view

FIG. 2

Transfer device in a plan view

FIG. 3

Sectional view of the transfer device in the direction of passage

FIG. 4

Multi-ram press with transfer device in a side view

FIG. 5

Sectional view in the direction of passage

Exemplary embodiment for use in a ram press

FIG. 1 shows a section of a press 1 in a side view in a simplified representation. You can see the stand 2, 3 at which a plunger 4 is guided vertically movable. The drive of the plunger 4 is not shown in this figure. Also not shown is the tool consisting of upper and lower tool. While the upper tool is connected to the plunger 4, the lower tool is mounted on a sliding table 5, which in turn is clamped during production with a table 6.

The transfer device 7 is attached on the one side via a crossbar 8 on the pair of stands 2 and on the other side via a crossbar 9 on the pair of stands 3.

FIG. 2 illustrates the cultivation situation in a plan view. The gripper rails 10, 11 are divided to enable a tool change. The gripper rail end pieces 10a, 10b and 11a, 11b remain in a tool change in the press 1, while the gripper rail parts 10 and 11 are moved out of the press 1 together with the tool and the sliding table 5. The gripper rail end pieces 10a, b, 11a, b are each suspended from three articulated rods or pairs of connecting rods and connected via these with the respective drives. The feed movement of the gripper rails 10 and 11 are generated via the drives 12a, b, which act on the gripper rail end piece 11b via pivot lever 13 and a link rod 14. Both the gripper rail end piece 11b with the articulated rod 14, and the articulated rod 14 with the pivot lever 13 are connected to each other via a spherical bearing 15. The drive trains for the feed movement are arranged on the stator pairs 3a, 3b in mirror image to the machine center 16. By contrast, the drive trains for the lifting movement and for the opening / closing movement engage on all four gripper rail end pieces 10a, b and 11a, b. A drive train for the lifting movement, for example, the gripper rail 10 consists of a drive 17, a pivot lever 18 and a pair of hinge rods 19. For the linear actuator not a single link rod but a pair of hinges 19 is provided so that tilting of the gripper rail 10 is prevented about its longitudinal axis. The pair of hinges 19 is similarly arranged a parallelogram, so that the orientation of the gripper rail 10 always remains the same. In FIG. 3 this arrangement is easy to recognize.

The drive train for the opening / closing movement consists of a drive 20, a pivot lever 21 and a link rod 22. As in all drive trains, the individual components are mounted spherically mounted together in this case. Characteristic of the opening / closing drive 20 is its position between the lifting drives 17, symmetrical to the machine center 16. The advantages of this arrangement have already been described, but problematic in this arrangement is the articulation of the gripper rails 10, 11 on the hinge rods 22 due to the space the articulation of the lifting drive 17 via the hinge rod pairs 19. The transfer device solves this problem in that the pivot rod 22 at her the Gripper rail facing the end is designed as a kind of fork, which encloses at least one articulated rod of the hinge rod pair 19 and so can act on a spherical joint 15 on the gripper rail 10, 11. Although in this description, the drive trains for the three movements feed, lift and open / close are described, it is apparent from the structural design that these movements can be realized only for themselves only from movement overlays of all drives. These motion overlays are calculated by a suitable controller and transmitted to the servo drives.

All drives are mounted on carriages 23 movable along a traverse 9. By means of a drive 24a, these can be moved, for example, via a spindle 24 / spindle nut 25 system. Other known from the prior art motion transmission means are conceivable.

Embodiment for use in a multi-ram press

In FIG. 4 the use of the transfer device 27 is shown in a multi-ram transfer press. As you can see, a transfer unit 27 is mounted in each stand area, consisting of lifting drive 17 and opening / closing drive 20 and the associated motion transmission means. The feed for the continuous gripper rails via a drive 29. Since the gripper rails 28 in multi-ram presses are usually very long and thus have a large mass, it is possible, as in FIG. 4 represented, two or more To use drives, which act on the same feed lever. Also shown is a variant of the transfer device 27 according to the invention, in which the axes of rotation of the pivot lever for the lifting movement and for the opening / closing movement are rotated by 90 °. This has the advantage that the space requirement of the transfer device 27 between the uprights is even lower.

In FIG. 5 This variant is shown in a view in the direction of passage. The pairs of connecting rods 19 for the lifting drive 17 are moved by a pivot lever 30, which pivots about an axis in the direction of passage. In the same direction pivots the lever 31 to drive the hinge rods 22 for the opening / closing movement.

The invention further provides that, instead of a pivoting lever 31 or 21, a linear drive is used for the opening / closing movement. The joint 32 could be stored, for example, on a carriage which is drivable in the vertical direction. The invention also provides that the opening / closing movement is effected by a dynamic change in length of the joint rod. These changes in length can be generated for example by a spindle mechanism, but other known in the art drive mechanisms, such as hydraulic cylinders are conceivable.

The invention further provides, the above-described dynamic change in length of the articulated rod in combination with a drive via pivot lever or a linear drive to use a movement overlay to improve the dynamics again.

The invention is not limited to the illustrated and described embodiments. It also includes all professional training in the context of the claims.

LIST OF REFERENCE NUMBERS

1

Press

2, 2a, b, 3, 3a, b

Stand, stand pair

4

tappet

5

sliding table

6

table

7

transfer device

8, 9

trusses

10, 11

gripper rails

10a, b

Greiferschienenendstücke

11a, b

Greiferschienenendstücke

12a, b

feed drives

13

Swing lever feed

14

Articulated rod feed

15

spherical bearing, universal joint

16

machine center

17

Linear actuator

18

Swing lever lifting drive

19

Joint rod pair

20

Opening / closing drive

21

Swing lever Close

22

Articulating rod closing

23

Carriage width adjustment

24

Spindle width adjustment

24a

Drive width adjustment

25

spindle nut

26

More ram Press

27

transfer unit

28

gripper rails

29

feed drives

30, 30a

Swing lever lifting

31

Swing lever Close

32

joints

Claims (15)

1. A press with a transfer device having a preferably multi-axial transport of work pieces through processing stations with two mounting- or gripper rails arranged parallel to each other, wherein through movement overlap of several drives a feed movement, a lifting-/lowering movement and an opening-/closing movement is carried out and wherein the mounting- or gripper rails are hung and guided by means of a joining rod arrangement for the implementation of the movements without additional guide elements, characterized In that the movement overlapping means (13, 14, 18, 19, 21, 22) are essentially arranged in the area between the columns (3a) and (3b) or (2a) and 2b) of the press, and that joining rods (22) for initiating an opening-/closing movement make contact from the direction of the center of the machine (16) to the gripper rails (10, 11).
2. A press according to claim 1, characterized in that the movement overlapping means is connected by means of spherical bearings both to the gripper rails (10, 11), as well as to the driving levers (13, 18, 21), as well as connected to each other.
3. A press according to claims 1 and/or 2, characterized in that the feed movements, the lifting-/lowering movements and the opening-/closing movements of the gripper rails (10, 11) are realized through movement overlaps of all of the drives used.
4. A press according to one or more of claims 1 to 3, characterized in that at least one joining rod (22) has a fork-like recess at the end facing the gripper rail (10), which envelops at least another joining rod (19).
5. A press according to one or more of claims 1 to 4, characterized in that the drives (20) for the opening-/closing movement and the associated driving levers (21) are arranged between the columns (3a, b, 2a, b) symmetrically to the center of the machine (16) and close to the center of the machine (16).
6. A press according to one or more of claims 1 to 5, characterized in that the drives (12, 17, 20) are firmly connected to a common carriage (23), which is mounted diagonally movable on a traverse (9), wherein in particular two carriages (23) are movable and/or adjustable by means of a common drive (24a) symmetrically to the center of the machine.
7. A press according to one or more of claims 1 to 6, characterized in that the turning of the swiveling lever (18) for the lifting drive and/or of the swiveling lever (21) for the closing movement occurs in a horizontal axis, transverse to the throughput direction and that preferably the turning of the swiveling lever (30) for the lifting movement and/or of the swiveling lever (31) for the closing movement occurs in a horizontal axis in the throughput direction.
8. A press according to one or more of claims 1 to 7, characterized in that the introduction of movement occurs on the joining rods (19) and/or (22) by means of linear drives acting vertically.
9. A press according to one or more of claims 1 to 8, characterized in that the opening-/closing movement of the gripper rails (10, 11) is generated by means of a dynamic change in length of the joining rod (22).
10. A press according to one or more of claims 1 to 9, characterized in that the lifting movement of the gripper rails (10, 11) is generated by means of a dynamic change in length of the joining rod (19).
11. A press according to claims 9 and 10, characterized in that the opening-/closing movement of the gripper rails (10, 11) is generated by means of a dynamic change of length of the joining rod (22) in connection with an introduction of movement through a swiveling lever (21) or a linear drive.
12. A press according to one or more of claims 1 to 11, characterized in that the drives of all of the joining rods occur via linear motors.
13. A press according to one or more of claims 1 to 12, characterized in that the contact points (15) of the joining rods (19) and (22) on the gripper rails are offset axially in or against the throughput direction.
14. A press according to one or more of claims 1 to 13, characterized in that the joining rods (22) is arranged as a double rod in front of and behind at least one of the joining rods (19).
15. A press according to one or more of claims 1 to 14, characterized in that the rotation axes of all of the swiveling levers can be arranged arbitrarily spatially.

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