EP3930937A1

EP3930937A1 - Feed apparatus for transfer press

Info

Publication number: EP3930937A1
Application number: EP20706313.2A
Authority: EP
Inventors: Matthias COMMON; Urs Graf
Original assignee: Adval Tech Holding AG
Current assignee: Adval Tech Holding AG
Priority date: 2019-03-01
Filing date: 2020-02-27
Publication date: 2022-01-05
Also published as: CH715796B1; JP2022522741A; BR112021017256A2; CH715795B1; US20220143675A1; ZA202106291B; WO2020178138A1; US11833569B2; EP3702062A1

Abstract

The invention relates to an apparatus (1) for the clocked longitudinal transport of workpieces (11) between at least two processing stations in a transfer press. The apparatus (1) has, at least on one side, a first (2) and a second (3) solely longitudinally movable control element as a control group (2, 3), wherein the two control elements (2, 3) are mounted so as to be movable relative to each other solely in the longitudinal direction, and the two control elements (2, 3) are driven via a common shaft (58). The first control element is a gripper rod (2) for the longitudinal transport of workpieces (11) between the processing stations, and at least two gripper elements (4), which are offset in the longitudinal direction by the distance between the processing stations, are mounted in the gripper rod (2) and can be moved solely in the transversal direction. The second control element is a thrust rod (3) which forcibly controls the transversal movement of the at least two gripper elements (4).

Description

TITLE

FEED DEVICE FOR TRANSFER PRESS

TECHNICAL AREA

The present invention relates to i.a. a feed device for a transfer press, a transfer press with such a feed device, and a method for operating such feed devices. Such devices are also referred to as transfer devices.

Transfer devices are distinguished from so-called progressive tools in that the part to be formed in the press is initially e.g. from an endless strip e.g. separated by cutting or punching and is then transported independently of the movement of the endless strip and mostly also perpendicular to it through the at least one processing station of the press.

The press is usually provided with several processing stations or forming stages connected in series. In the case of progressive tools, on the other hand, the part to be formed is transported from forming stage to forming stage by its own continuous strip from which it originates.

STATE OF THE ART

Transfer press plants are industrial units with several clocked presses for the sequential processing of workpieces, whereby steps such as punching, forming, ironing can be performed sequentially or partially simultaneously (in particular punching and forming) in one station on the same workpiece, in particular in processing stations connected one after the other, possibly in Combination with other operations such as quality control, cooling, heating, etc. Such devices can be operated with very high clock frequencies and are mainly used for the production of metallic components in large quantities, for example in the automotive sector for structural components, in the furniture sector and in the telecommunications sector, respectively Computer area also for structural components, but also in the food area for the production of containers such as pots, food bowls, also for example Kaffeeka made of aluminum or tinplate.

So-called transfer devices are provided for the transport between the various processing stations. These grip the machined workpiece after completion of the respective operation, and transport it in the longitudinal direction to the position of the next processing station, in order to release it there at the right time, ie usually at the time when a positioning element or insertion element of the tool has reached into the workpiece or is about to do so .

Such transfer devices must on the one hand be able to safely transport the workpieces between the stations with the high clock frequencies in the short period of time in which the tool is open, and on the other hand they must also be able not only to grasp the workpiece in the correct position and to put it down again, but also to do this in such a way that, for example, metallic workpieces with small wall thicknesses are not deformed during transport and rejects or machine downtimes can be avoided. The transfer devices are accordingly not only to be optimally adapted to the stroke of the press, but they are also to be provided very well controlled and adjustable with regard to the transport route and the treatment of the workpiece during transport.

Transfer systems of the type described above are known in principle, e.g. from EP 490 821, EP 504 098, CH 688 128, EP 694 350, WO00 / 20305 and W02004 / 110667. In EP 0 490 821 A1, the transport rods are driven by mechanical coupling with moving parts of the press, namely in the longitudinal direction by decreasing the movement of the eccentric shaft of the press via a gear and in the transverse direction by decreasing the movement of the ram of the press by means of control rails, whereby high stroke rates in the range of 300 cycles per minute can be achieved. For special applications in the can area, even up to 700 cycles per minute are achieved. The mechanical coupling also means that collisions between the press tool and the means of transport can be largely prevented. The parts to be formed are each gripped by two rigid grippers for transport, transported longitudinally and then released again at the next station for the next processing.

Furthermore, from US 4,404,837 a reversing press for producing several drawn metal containers is known which combines the functions of cupping and drawing presses in one press. The press contains a punching and deep-drawing station as well as several drawing and redrawing stations arranged next to one another, which are connected in series by a slide arrangement that can be moved vertically to and fro. The material, semi-finished or finished product is under complete control in every operating phase. A method of making a drawn container by multiple molding and reshaping of a drawn article is also provided. US 3,939,992 describes a workpiece transfer mechanism having a base with spaced parallel sliders mounted in spaced parallel paths, crank levers whose central parts are pivotally mounted on the sliders and whose first parts are pivotally attached to work piece engaging elements and whose second parts are connected by tie rods with the required Force are connected to overcome the frictional engagement between the sliders and the paths that are greater than the force required to pivot the crank levers. This causes a unidirectional force to be applied to the tie rods, the workpiece engaging elements produce a unidirectional force prior to the time of engagement with the workpiece, and the carriages move so that the workpiece is transferred from one position to another.

DISCLOSURE OF THE INVENTION

Accordingly, among other things, the subject matter of the present invention is to provide an improved device for the clocked longitudinal transport of workpieces between at least two processing stations in a transfer press, especially for high clock frequencies and sensitive workpieces, for example metallic workpieces with thin walls. The present invention also provides a transfer press with such a device, as well as methods and uses in connection with such devices.

This object is achieved by the subjects of the appended claims.

According to a first aspect of the invention, the device is particularly characterized in that it has a first and a second exclusively longitudinally displaceable control element on at least one side (in the transverse direction with respect to a sequence of processing stations in a transfer press). Such a combination of a first and second exclusively longitudinally displaceable control element forms a so-called control group. The two control elements are mounted displaceably relative to one another in an exclusively longitudinal direction, and both control elements are preferably driven via a common shaft.

The longitudinal direction is defined as the direction in the tool along which the machining stations are offset in their sequence and along which the workpieces are transported between the machining stations. The transverse direction is to be understood as the horizontal direction perpendicular to the aforementioned longitudinal direction. This is typically the direction of movement below described gripper elements. The third direction is defined as the vertical direction, which is perpendicular to the longitudinal direction and the transverse direction. According to the invention, the first control element is a gripper rod for the longitudinal transport of the workpieces between the processing stations, and at least two gripper elements are mounted in the gripper rod, offset in the longitudinal direction by the distance between the respective processing stations of the press, which in turn are only shifted in the transverse direction can be.

The second control element is a push rod which positively controls the transverse movement of the at least two gripper elements, e.g. via a curve control.

In other words, the transfer device contains a control group on at least one side, each of which contains a gripper rod and a push rod, both of these rods are only displaceable in the longitudinal direction. The push rod now automatically controls the transverse movement of the gripper elements in the transport process, preferably by means (e.g. cam control), which are described below. It is thus possible to control the feed movement of the workpieces essentially via the movement of the gripper rod, and to this end synchronize the transverse movement of the gripper elements stored therein via the push rod of the control group. Even at high cycle frequencies, this means that the process can be optimally adjusted to the tool cycle, especially at the point in time or in the phase of gripping and letting go of the workpiece, so that the transfer between the transfer device and tool (in both directions) is controlled smoothly and even with delicate workpieces expires.

A first preferred embodiment of the proposed device is characterized in that the push rod is mounted so as to slide at least in sections in or on the gripper rod. This, for example and preferably in a longitudinal groove, which is preferably at least partially open at the top and / or partially closed by covers. This groove can for example extend over the entire length of the gripper rod, for example in the form of a rectangular groove, and the push rod can be inserted into this groove as a corresponding rod. The sliding of the push rod can be facilitated with this arrangement, for example, by providing roller or ball bearings on the gripper rod and / or on the push rod, or by means of corresponding sections with sliding bearings, for example made of specially coated hardened steel.

Push rod and gripper rod can have two of the common shaft driven but individual cam gears are moved for the respective rod. If there are several control groups, then preferably all push rods of these groups are driven by the same cam gear and all gripper rods from the same cam gear. The two cam gears for the push rod or the gripper rod preferably generate essentially the same or at least very similar movement but with a relative phase shift in each case before reaching, while reaching and / or after reaching the two end positions.

According to a second aspect, the invention relates to a device on a press for the step-by-step transport of workpieces in a longitudinal direction from a receiving station through at least one processing station of the press with transport means for the workpieces, which are cyclical and possibly also synchronous with the movement of the press in the longitudinal direction as well as being moved to and fro in a transverse direction perpendicular thereto, at least in part or in regions, for gripping or releasing the workpieces. The transport means are moved in the longitudinal direction via an external drive synchronized with the movement of the press. The external motor drive takes place via a cam gear with a feed lever driven by this, which moves the transport means back and forth in the longitudinal direction, without reversing the rotation of the external drive. According to the invention according to this second aspect, the feed lever has at least two cam rollers on its gear-side arm for coupling to the worm on the rotor of the cam gear, these cam rollers rolling on the opposite flanks of the worm, which are axial with respect to the axis of the rotor.

This second aspect of the invention is preferably used in combination with the above-mentioned first aspect, but can also be used independently of this, and therefore also represents a separate invention.

In such worm gears, the worm and the element engaging it typically slide against one another in an oil bath. It has been shown, however, that such constructions can be problematic at the high clock frequencies that are required in the present applications and the high accelerations associated with them.

The proposed solution with the cam rollers proves to be unexpectedly structurally simple, reliable and stable.

A preferred embodiment of the proposed construction is characterized in that the two cam rollers enclose an angle of at least 5 °, preferably at least 10 °, and the flanks of the worm are designed to converge towards the crest of the worm and are substantially at an angle Include the same or exactly the same angle as that between the cam rollers. The cam mechanism can have a lower housing in which the rotor is mounted, and an upper housing in which the feed lever is mounted, the axis of the rotor being perpendicular to the axis of the feed lever.

The transfer-side arm of the feed lever can protrude from the upper housing, the passage opening in the upper housing preferably being sealed by a flexible seal.

It is particularly preferably possible to carry the push rod with the cam mechanism for the push rod in the forward movement synchronously with the gripper rod until the gripper rod has reached the end position at the front, and then the push rod for releasing the workpieces without moving the gripper rod (or with a simultaneous lower backward movement than that of the push rod) to move back a little. The exact longitudinal end position of the workpiece is specified via the end position of the gripper bars at the front, and the release movement of the grippers is decoupled from it and implemented via the push rod.

Analogous to the backward movement, here too the push rod can be moved synchronously with the gripper bar in the backward movement until the gripper bar has reached the end position at the rear, in order to then use the push rod to release the workpieces without moving the gripper bar (or with a simultaneous lower forward movement than that of the push rod) a little forwards to close the gripper. The exact longitudinal takeover position for the workpiece is specified via the end position of the gripper bars at the rear, and the gripping movement of the grippers is decoupled from this and implemented via the push rod.

Using a corresponding setting (curve control) between the push rod and the gripper elements, the transverse movement of the gripper elements can then be controlled in a targeted manner at the right moment in the process for gripping or releasing the workpieces.

For the implementation of such a control, the gripper elements preferably have at least one recess or passage opening in the form of a link, which is preferably open in the vertical direction, and the push rod has an extension at the position of the corresponding gripper element that automatically controls the transverse movement of the gripper elements or such a preferably vertical pin engaging.

In the sense of a kinematic interchangeability, it is alternatively possible that the push rod in each case at the position of the corresponding gripper element has at least one recess or through opening open in the vertical direction in the form of a Has gate, and that the gripper elements have an extension or corresponding pin which inevitably engages in this gate to control the transverse movement of the gripper elements.

The extensions or pins preferably have a circular cross-sectional area in order to slide optimally in the backdrop.

The link in the gripper elements can each have a first area for retracted gripper element and a second area for extended gripper element and a displacement area connecting these two areas. The first area in the gripper element is preferably arranged closer to the workpiece in the transverse direction than the second area, and the displacement area is designed as a linear or curved, in particular S-shaped, connecting channel or connecting passage opening. The first area and the second area can individually or both run linearly over a certain longitudinal length, and the ends of the link generally terminate preferably via a curvature which corresponds to the outer line of the corresponding guide pin.

The device preferably has such first and second control elements, i.e. control groups, on both sides of a longitudinal row of processing stations, the transverse movement of the respective transversely opposite gripper elements being necessarily controlled mirror-symmetrically with respect to the workpiece position. For this purpose, corresponding scenes in the form of recesses or through openings are preferably designed mirror-symmetrically with respect to the central longitudinal axis of the tool.

Such a device is preferably characterized in that it is provided for transport between at least two, preferably 2-5 or 2-4 longitudinal rows (the rows are offset in the transverse direction) of processing stations of the same transfer press, and a number greater by one of each of the first and second control elements as the number of rows of processing stations. Control groups located between two rows provide the functionality in both transversal directions, i.e. H. simultaneously carry the grippers for both sides and control them for both sides, preferably with only one gripper rod and only one push rod. Preferably, the processing stations of tools arranged in adjacent rows are not at the same height in the longitudinal direction, but instead are offset alternately, for example.

The first control elements arranged between rows of processing stations preferably store gripper elements and protruding in both transverse directions the second control elements preferably simultaneously forcibly control the gripper elements in both transverse directions. The links in the gripper elements protruding in different transverse directions are preferably designed to be mirror-symmetrical with respect to the longitudinal direction. But it is also possible, especially in the case of spring-loaded grips (see discussion below), to design the scenes in the different transverse directions in such a way that the gripper elements do not contact the workpiece with a mirror symmetry and thus offset in time.

The first control elements arranged between rows of processing stations preferably have transversely running through openings in which the gripper elements or gripper carriers of gripper elements are displaceably mounted. In the longitudinal direction, gripper elements are usually alternately mounted in one and the other transverse direction.

The movement of the first control elements of the control groups arranged in parallel is preferably controlled via a common transversely extending coupling cross member for the gripper bars, and the second control elements via a common transversely extending coupling cross member for the push rods. The coupling cross member for the gripper bars is connected to a cam gear for the gripper bars, preferably via at least one coupling rod, and the coupling cross member for the push rods is connected to a cam gear for the push rods, preferably via at least one coupling rod.

At least one of the gripper elements preferably itself or on a gripper pin has a fork-shaped and / or curved gripping area facing the tool for at least partially surrounding the workpiece, the gripping area preferably being adapted to the radius of the workpiece in the corresponding transport section.

Or at least one of the gripper elements has an essentially planar gripper tip facing the workpiece. Gripper elements that are opposite to the workpiece and grip the same tool preferably have a substantially planar gripper tip on one side and a fork-shaped and / or curved gripping area on the other side when workpieces with circular symmetry are to be transported between the processing stations, e.g. containers or can sections.

At least one of the gripper elements can have a gripper carrier which is mounted exclusively transversely displaceably in the gripper rod, and which has a gripper pin displaceably in this gripper carrier, which is preferably elastic is braced against the workpiece, preferably by means of a spring, in particular a spiral spring, or by means of compressed air or an elastomer spring, the return preferably being configured to be adjustable.

In other words, according to a further embodiment or a third aspect of this invention, such a device is characterized in that the workpieces between the processing stations are gripped from both sides with a gripper each, transported in the gripped state in the longitudinal direction to the next processing station and again in the next processing station are released, and that at least one of the grippers is spring-loaded and designed with an elastic restoring force against the workpiece. This third aspect is to be regarded as an invention independently of the above-mentioned specific features of the transfer device, but is preferably used in combination with the above-mentioned features of the transfer device. According to this third aspect of the invention, these spring-loaded grippers can also be used in connection with a device for the step-by-step transport of workpieces in a longitudinal direction from a receiving station through at least one processing station of the press with transport means for the workpieces, which are cyclic and synchronous with the movement of the press be moved back and forth at least partially or in regions in the longitudinal direction and for gripping or releasing the workpieces in a transverse direction perpendicular thereto. The device is improved in particular with regard to the gripping of the workpieces by the suspension. The transport means can be rod-shaped, and the grippers can be firmly attached to these rods. Then the means of transport move as a whole both in the longitudinal direction and in the transverse direction, quasi in a rectangular movement. However, the transport means can also be designed in such a way that the grippers are movably attached to such rods, and consequently the rods then only perform longitudinal movements, and the grippers perform a separate transverse movement on these rods. This transverse movement can either be actively controlled, or it can be controlled in that the workpieces are pushed between the grippers.

The spring-loaded design of the grippers enables a significantly more flexible and reliable process control, and it is also possible to process different materials, including soft materials, in such devices. A first preferred embodiment of the proposed invention according to this third aspect is characterized in that the suspension of the at least one gripper is formed by an elastic spring element, this spring element preferably by a leaf spring, compressed air, a spiral spring, or an elastomer spring is formed.

Another preferred embodiment of the proposed device is characterized in that spring-loaded grippers are arranged on both sides of the workpiece.

A spring-loaded gripper can only be arranged on one side of the workpiece, and an unsprung gripper on the opposite side.

The transverse movement of the transport means or gripper elements arranged on opposite sides of the workpiece is then preferably not necessarily controlled mirror-symmetrically with respect to the workpiece position, with the transverse movement being preferably controlled asymmetrically. As a result, the unsprung gripper does not hit the part, as it only moves up to the part. The spring-loaded gripper moves asymmetrically (later) to position so that the part is not pushed out of position by the spring force. The speed of impact is defined by the shape of the drive curve of the gripper.

Depending on the respective processing stations, the areas of the gripper elements that contact the respective workpiece or the gripper pins stored in a gripper carrier can be arranged at different heights in the vertical direction, preferably in that the gripper elements or the gripper pins have two horizontal sections and one vertical section connecting them.

The present invention further relates to a method for transporting workpieces between different processing stations of a transfer press, which is particularly characterized in that at least one device as described above is used for the transport between the stations.

This involves a method for the step-by-step production of workpieces, in particular starting from a flat, strip-shaped starting material, preferably made of metal, particularly preferably steel or aluminum, using a device as set out above.

The method is preferably characterized in that, preferably after a first punching step and a subsequent first reshaping step, the workpiece is gripped at least once from both sides by a pair of grippers and transported to a subsequent processing station.

Both grippers can be designed to be sprung, and the transverse movement of the transport means can consist at least partially or exclusively in that the workpieces are pushed by the machining tool at this machining station against the spring force of the grippers to hold them. Or the method can be characterized in that only one of the grippers is spring-loaded, and that the transverse movement of the transport means or gripper elements arranged on opposite sides of the workpiece is not necessarily controlled mirror-symmetrically with respect to the workpiece position, the control of the transverse movement preferably being carried out asymmetrically so that the impact speed of the spring-loaded gripper on the part is lower than that of the non-spring-loaded gripper .

In addition, the present invention relates to a transfer press with a device as described above, preferably a transfer press with several rows of processing stations offset in the transverse direction.

Finally, the present invention relates to the use of a device as described above in a transfer press, preferably a transfer press with several rows of processing stations offset in the transverse direction.

The present invention further relates to a workpiece, in particular a cup-shaped, stamped and formed workpiece, preferably made of metal, produced using a device as shown above or in a method as explained above.

Further embodiments are given in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below with reference to the drawings, which are only used for explanation and are not to be interpreted as restrictive. In the drawings show:

1 shows a transfer device in a perspective view with five gripper bars for four processing lines with seven stations in each line;

FIG. 2 shows the transfer device according to FIG. 1 in a top view with closed

Grippers;

3 shows the transfer device according to FIG. 1 in a top view with the open

Grippers;

Fig. 4 shows the section along A-A in Fig. 2;

Fig. 5 shows the section along B-B in Fig. 3;

6 shows the section along C-C in FIG. 4 (bottom);

7 shows the section along D-D in FIG. 5;

8 is a perspective view of the coupling area of a gripper bar;

Fig. 9 is a perspective view of the coupling area of the whole

Transfer device with five gripper bars;

10 side view of an entire transfer press with processing stations, Transfer device as well as gears and coupling elements for driving the transfer device;

11 the transmission and coupling of the transfer processing system according to FIG. 10 in a sectional view;

12 asymmetrical control of the transverse movement of the grippers;

13 in a) a schematic illustration of the transfer system with a drive with a variable feed time or with variable angles, and in b) a section through the worm gear / cam gear and the feed lever of an embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1, a feed device is shown in a perspective illustration, the feed device 1 being designed for a press with four processing lines which are each offset in the transverse direction 68. The transfer device is provided along the longitudinal direction 67 for seven processing stations of the press tool, which implement various processing steps on the workpiece.

Also shown in FIG. 1 are, by way of example, workpieces in the various processing stations, although they are not gripped by the grippers. The workpiece 11 is a cup-shaped component that is formed into a cup-shaped blank 11.1 in the first processing station (furthest to the left in the figure) .In this step, a corresponding circular sheet metal section is typically punched out in the same tool in immediate succession and then into one Pot 11.1 pulled.

The next processing station then follows, offset in the longitudinal direction 67, here the cup-shaped component is further deformed into component 11.2.

Further processing steps follow for the stepwise formed components 11.3, 11.4, 11.5, 11.6 and 11.7. Often the last stage, in which the component 11.7 is shown, is not a further processing stage, but here the component 11.7, which is then identical to that shown with 11.6, is only transported to the corresponding position and either transferred to another handling device or released into a corresponding guide and dropped.

The feed device 1 now has control groups in the form of rods in each case, with two external control groups G1 and G5, each of which only has grippers directed inwards to a certain extent on one side. The control groups G2-G4, which are arranged between two rows, each simultaneously serve the two processing stations that are adjacent in the transverse direction. Such a control group G is made up of a gripper rod 2 and a push rod 3 guided in a longitudinal upwardly open groove 18. This groove 18 is covered in sections by covers 10. The cover 10 can, as shown here, only be designed in sections in individual sections However, the cover 10 can also be formed essentially over the length of the entire gripper rod 2.

The gripper bars 2 have transverse through-openings 8 and 9. Certain of these through-openings, specifically the quasi-first through-opening indicated with the reference number 8, each has no special function. The row of transverse through-openings 9 which then follow in the longitudinal direction serves to receive the gripping elements 4 and to store them in a transversely movable manner.

The gripper elements 4 are each constructed on one side from a gripper carrier 7 in which a gripper pin 5 is mounted. The gripper carrier 7 is slidably mounted in a through opening 9 of the gripper bar. Only every second through opening is equipped with a gripper element in the outer gripper bars G1 and G5. The through openings in between are exposed.

The situation is different with the gripper bars G2-G4 located between two processing lines. Here, gripper elements 4 are alternately mounted in the through openings 9, which protrude alternately in different transverse directions from the gripper bar 2 and serve the two different processing lines on both sides.

The tools of the four rows of processing lines, which are provided here next to one another, are accordingly not all arranged on one line in the transverse direction so that this transfer device can be used, but are alternately offset by the offset of the transverse through openings 9.

The various processing stations along the line in the longitudinal direction may process the workpieces at different vertical heights, or the workpieces must be gripped at different vertical positions, although the tools are arranged at the same height. For this purpose, the gripper elements 4 are each stepped, so in the first processing station they are offset downwards to the maximum for gripping the workpiece 11.1, then successively further up to the position at the workpiece 11.4, and then always at the same vertical height until the last position .

At the input end, the push rod has a coupling element 12, the function of which is explained below. Analogously, each gripper bar 2 has a coupling element 13, which here is directed vertically downwards. Corresponding set screws 14 and 15 allow optimum adjustment of both the gripper bar and the coupling element.

The gripper elements 4 protruding from the respective gripper bar on the right-hand side in FIG. 1 are, as explained above, made up of two elements, a gripper carrier 7 in which a gripper pin 5 is mounted. The opposing gripper elements 4, which protrude to the left or at an angle to the top left in the case of the gripper bars G1-G4 in FIG. 1, are not designed in two pieces, but as one-piece gripper forks 6. These gripper forks 6 have curved gripping areas, which will be explained in detail below, In contrast to the ends of the gripper pins 5 facing the workpieces, these have no guiding function in the longitudinal direction.

FIG. 2 shows such a feed device in a view from above in the position in which the grippers are each closed, thus each gripping the workpiece, which is only shown schematically here, in each case. This is the position in which the feed device is to a certain extent fixed in that time segment in which the workpieces are transported between the individual processing zones. In this figure it can also be seen how the grippers in adjacent rows are each offset in the longitudinal direction so that it is possible to optimally store the gripper elements 4 in the bars G2-G4 in the transverse through openings 9 of the gripper bars 3.

FIG. 3 also shows such a feed device, but now in the somewhat open position, that is to say in that position in which the gripper elements are each withdrawn and do not hold the workpiece. This is the position shortly before the workpiece is gripped before a transfer step or the position after the workpiece is released at the end of a transfer step. This is also the position in which the backward movement of the feed device is carried out.

FIG. 4 shows the section along the line AA as indicated in FIG. 2. It can be seen here how the gripper pins are arranged at different vertical heights. The gripper pin 5.1 and that from the next station, that is 5.2, are arranged furthest vertically at the bottom and accordingly grip the cup-shaped workpiece vertically deepest. Then a medium height follows in the third station, here the gripper pin is labeled 5.3, and then the linear gripper pins 5.4-5.7 follow. This applies to the left-hand side, where the gripper elements are made up of two parts, comprising gripper carriers 7 and gripper pin 5. On the opposite side, the corresponding gripper forks 6 are also stepped, in the first station in the form of gripper forks 6.1 and 6.2, in the middle vertical gripper position as a gripper fork 6.3 and then as Gripper forks 6.4 for the following stations 4-7.

In addition, it can be seen in Figure 4 how the coupling element 13 for the gripper rod 2 is designed in the form of a fork, with the two fork arms 16 which protrude downward. It can also be seen how the push rod 3 is designed as a solid rod with a square cross-sectional area and slides in the groove 18 in the gripper rod 2. The sectional views at G1-G3 also show how the covers also have a downwardly open longitudinal groove 19 for better guidance of the gripper bar.

In particular, on the basis of the sectional view at G2 in FIG. 4, it can also be seen how the guide pin 5 is spring-mounted in a recess provided for this purpose in the gripper carrier 7; this will be explained in detail below. It can also be seen how the gripper bars 2 have a V-shaped profile downwards; this is, for example, sliding in a V-shaped groove in a support structure which is stationary so that the gripper bars can slide in it in a controlled manner. As indicated by correspondingly darker areas, special sliding elements or coatings, for example made of PTFE, can be provided in or on the lower surfaces of the gripper bars.

FIG. 5 shows a section along the line B-B in FIG. The open position of the grippers is therefore illustrated here, which can also be seen in the fact that the link openings 26, which are explained further below, are now shown laterally on the outside with respect to push rods 2.

FIG. 6 shows the section along the line C-C in FIG. 4 (bottom). In this sectional view, the compulsory control of the gripper elements and the specific design of the gripper elements for the closed state can be seen. The open state is illustrated in accordance with step D-D in FIG.

First to FIG. 6: Here it can be seen how the gripper carrier 7 is mounted in the respective gripper bar 2 in the transverse through opening 9 on the left side. To make the gripper carrier 7 easier to move, slide plates 20 can be provided, not only, as can be seen here, in the longitudinal direction on the boundary walls, but also in the vertical direction, that is, above and below in the recess 9 at the respective gripper carrier 7 Such gripper carrier 7 slides with its left-hand area in the recess 9, and on the right side the gripper carrier tapers to an extension which has a recess 22 in the form of a blind hole for the gripper pin. At its end facing away from the workpiece, the gripper pin 5 has a piston-shaped enlargement 21; this piston 21 is provided in an enlargement area of the passage 22 in the gripper carrier 7. in the In the inner region 24 of the passage 22, a spring element 25 in the form of a spiral spring is provided. This spiral spring 25 braces the gripper pin 5 towards the workpiece until the piston 21 stops at the widening 23 of the passage 22. This optionally adjustable spring 25 can be used to set the most gentle and always optimal gripping force even on sensitive workpieces.

At the end facing the tool, the gripper pin 5 has a gripper tip 34 which is linear, that is to say runs along the longitudinal direction. This gripper element 4 therefore only has a clamping effect in the transverse direction and no guiding effect in the longitudinal direction.

This is in contrast to the one-piece gripper forks, which are arranged opposite one another and are indicated with the reference number 6. At their end facing the workpiece, these have a fork region 32 in the form of an extension, and the region of this extension facing the tool is provided as a curved gripping region 33, preferably with a curvature that is adapted to the radius of curvature of the workpiece at this position.

Both the gripper carrier 7 and the rear area of the gripper fork 6, i.e. the extension 31, now have the vertical link openings 26, which are important in the present context. These link openings 26 are used for the forced control of the transverse position of the gripper elements 4 by the push rod 3 the gate openings 26 are designed to be round, stepped in the transverse direction. There is an area of the stop position 27 for the retracted gripper, and an area of the stop position 28 for the extended gripper. The position 27 is arranged on the workpiece side, and the extended position 28 is offset in the transverse direction further outward from the workpiece. In between there is a connection area or displacement area 29 which connects the areas 27 and 28 to one another.

The link openings 26 in the opposite gripper carriers 7 or extensions 31 are designed mirror-symmetrically with respect to the longitudinal axis 67.

A vertical link pin 30 now runs in this gate 26, which is firmly attached to the push rod 3 and protrudes from this down into the gate opening 26. If, starting from the position shown in FIG. 6, the push rod 3 is moved downwards or backwards in the feed device of the tool in the longitudinal direction, the vertical link pin 30 also moves down with it. It cannot be shifted in the transverse direction; accordingly, the gripper carrier 7 shifts on the left side due to the migration of the pin 30 in the backdrop 26 to the left. If the push rod 3 is also moved down on the right side, the pin 30 moves analogously downwards and the rear extension 31 is moved to the right by this cam control. The position shown in FIG. 7 is thus achieved. The grippers are now open.

This control can take place either in that the push rod 3 moves downwards with the gripper rod 32 stationary, as described above, or by the push rod 3 remaining fixed and, starting from the position in FIG. 6, the gripper rod 2 being pushed further upwards than the Push rod 3.

In the transfer process, the control of the gripping movement is now implemented in such a way that, starting from the position in FIG. 6, the gripped workpiece is moved to the next processing station by synchronous longitudinal movement of the gripper rod and push rod. When the next position is reached, the push rod 3 is now shifted slightly back without moving the gripper rod, namely by a longitudinal offset which corresponds to the longitudinal distance between the positions 27 and 28. The push rod 3 therefore moves back somewhat relative to the gripper rod 3 and the control in the link 26 automatically releases the workpiece in the correct position via the pin 30 through the transition illustrated in FIGS. 6 and 7.

When the workpiece has been released, the transfer device now moves back to the first processing station in a position as shown in FIG. Now, when the gripper bar has reached the end position, the push rod 3 is again shifted forwards somewhat without moving the gripper bar, namely by the longitudinal offset between 27 and 28, so that the workpiece can be gripped at the right moment in what is again the first processing station, consequently the grippers close, which corresponds to the transition from FIG. 7 to FIG.

Thus, the relative movements of push rod 3 and gripper rod 2 are each slightly out of phase in the movement section shortly after arriving at the transfer position and shortly after arriving at the transfer position, and the push rod 3 takes a different path, which is achieved by cam gears, which are set out below become.

In FIG. 12, the asymmetrical guidance of the transverse movement is now illustrated for the situation in which one of the grippers is spring-loaded (on the left). The gripper shown on the right-hand side has the same design as that which was explained in connection with FIG. The construction of the opposite spring-loaded gripper is basically also analogous to that which was shown in FIG. 7, but it differs from the construction with regard to the gate opening 26 7. While in FIG. 7 the gate openings of the two opposite grippers are symmetrical, the gate opening 26 of the spring-loaded gripper is connected to an arcuate curved area 70 between the two stop positions 27 (retracted position) and 28 (closed position). There are therefore not areas in the link opening between the two end positions in which there is no lateral displacement of the gripper, between a short displacement area 29, but the displacement takes place more slowly over the entire curved area 70 between the two stop positions 27/28. This asymmetrical guidance takes into account the fact that a spring-loaded gripper 5 is arranged on one side and a non-spring-loaded gripper 6 is arranged on the other side.

FIG. 8 shows the coupling area of the gripper rod 2 and the push rod 3, in particular the coupling elements 13 and 12, in a perspective view. In particular, the upwardly directed projection 17 of the coupling element 12 can be seen, which serves to engage in a cross member.

FIG. 9 shows how all the push rods 3 of the control groups G arranged in a row in the transverse direction are moved in their longitudinal direction via a coordinated common device. For this purpose there is a coupling cross member 35 which has vertical recesses 36 in which the upwardly directed projections 17 of the push rods 3 engage. The transversely extending coupling cross member 35 is coupled via a swivel joint 37 via an axle 40 to a fork element 39 which is connected to a coupling rod 38. In other words, a back and forth movement of the coupling rod 38 moves the entire coupling cross member 35 and thus also all push rods of the five gripper carriers G1-G5 in a synchronized manner.

Analogously, the gripper bars 2 are synchronously controlled by a common coupling cross member 41, which in turn has vertical recesses 42 into which the coupling elements 13 engage with their fork arms 16 from above. This coupling cross member 41 is also common to all gripper bars of the entire feed device and is in turn connected to a coupling rod 47 via an axle 46 and a coupling joint 45. The coupling cross member 41 runs on a guide cylinder 44 which is contained in a carrier element 43.

FIG. 10 shows how the movement of the two cross members 35 and 41 are controlled in the overall context. The illustration also shows the upper tool plate 49 and the lower tool plate 50 of the entire press, as well as the guide columns 51 between these two plates. Furthermore a lower support plate 48 of the entire transfer unit on which the aforementioned carrier unit 41 is also attached.

The movement of the entire feed device is now implemented via a common drive axis 58. This drives two different cam gears 46 and 47. The cam gear 56 is used to control the push rods, and the cam gear 57 is used to control and move the gripper bars and move the gripper bars. The cam gears are each shifted to the coupling rods 38 and 47 via gear levers 44 or 55 and deflections 52 and 53, respectively.

As can be seen in particular from FIG. 11, these two cam gears now have individual cam sections 61 and 62, cam arms 63 and 65 and cam ribs 64 and 66 respectively. The design of cam ribs 64 and 66 now provides the above-described movement characteristics of gripper rods 2 and push rods 3 coordinated, therefore controlled, that the push rod reaches a later stop in the takeover and delivery position than the gripper rod.

FIG. 13 a) shows a schematic representation of the transfer system with such a drive with a variable feed time or with variable angles. A servomotor 35 'with a variable number of revolutions and an angular incremental encoder drives a mechanical cam gear 38', in which the sectors are designed according to optimal criteria for a maximum number of cycles of the press 3T. This optimization is usually designed for a constant speed of the motor. A reduction gear 36 'can also be arranged between the servomotor 35' and the cam gear 38 '. The servomotor 35 'is an electric motor which can be switched, ie whose power is controllable. For example, a servomotor 35 'with 3000 revolutions / min can be used, and a reduction gear 36' with a factor of 1:10, so that a rotation of 300 revolutions / min is applied to the transfer gear 38 '. The servomotor 35 'is synchronized via a control from an angular incremental encoder 32' which is driven by the eccentric shaft of the press 3T. In order to ensure synchronization, the servomotor 35 'also has an angle encoder. The angle incremental encoder is an electronic assembly which is able to divide a rotation of a shaft (e.g. eccentric shaft of the press) of 360 'into increments of, for example, 0.044 and to precisely calculate the respective angular position of the eccentric shaft. The transfer gear 38 'comprises a worm gear 37' which generates a longitudinal movement from the rotary movement of the servomotor 35 '. This longitudinal movement is carried out via a feed lever 34 ' the axis 44 'transferred to the transport rods 4'. If you now drive with the maximum number of cycles, according to the interpretation of the curve law of the transfer gear 38 ', the servo motor 35' runs at a constant rotation, which corresponds exactly to the rotation of the eccentric shaft of the press 3T. In this mode of operation, the system runs exactly as if the gear 38 'were driven directly by the eccentric shaft of the press 31'. If you want to use the advantages of the servo motor 35 ', the number of revolutions of the motor 35' can be changed in the individual curve sectors. Thus, with a fixed feed path 33 ', a variable feed time can be allowed.

Figure 13b) shows a section through a worm gear for driving a transfer device. It is not a classic worm gear that converts a rotation around a first axis into a rotation around the other axis, but rather a worm gear that converts a rotation around a first axis into a rocking movement of the feed lever. Correspondingly, a thread is not provided on the rotating rotor 5T, but rather a worm 40 'which forms a closed contour that runs continuously around the circumference of the rotor 5T. When unfolded, this contour essentially describes a wave shape, the characteristics of this wave shape being predetermined by the desired movement of the feed lever. The drive hub 39 'of this transmission is driven in rotation by a motor. This drive hub 39 'is mounted in a housing 4T which is closed on the side opposite the drive hub 39' by a housing cover 43 '. The stub shaft 42 'protrudes through this housing cover 43'. In the housing 4T, the rotor 52 'runs driven by the hub 39'. The feed lever 34 'is for its part pivotably mounted via an axis of rotation 44' oriented perpendicular to the axis of the drive hub 39 '. The lower part of this feed lever 34 ', the gear-side arm 48' of this lever, is arranged in an upper housing 50 'of the gearbox. At its lower end, the gear-side arm 48 'has two cam rollers 45' which touch the worm 40 'on the two axial flanks 53' which are lateral with respect to the axis of the drive hub 39 'and which roll on these flanks 53'. The cam rollers 45 'are embedded with their axes 46' in corresponding bearing bushes 47 'at the lower end of the arm 48' on the transmission side. The two axes 46 'of the two cam rollers 45' are not arranged in parallel, but at an angle of at least 10 °, so that they converge around the worm 40 'to the arm 48'. The arm 49 ′ on the transfer side protrudes beyond the housing 50 ′ and is sealed by a flexible seal 51 so that the upper part of the housing 50 ′ and thus also the entire worm gear are protected. REFERENCE LIST

Feed device 22 passage in 7

Grab bar 23 extension of 22

Push rod 24 inner area of 22 gripper element 25 spring element

Gripper pin 26 vertical gate opening in 7 gripper pin in station 1 27 stop position gripper gripper pin in station 2 withdrawn from 26 gripper pin in station 3 28 stop position gripper gripper pin in stations 4-7 extended from 26

Gripper fork 29 Shift range from 26 gripper fork in station 1 30 vertical link pin for 26 gripper fork in station 2 to 3

Gripper fork in station 3 31 Rear extension of 6 gripper fork in stations 4-7 32 Fork area of 6

Gripper carrier for 5 33 curved gripping area from transverse 6

Through openings in 2 34 gripper tip of 5 transverse 35 coupling cross members for through openings for push rods

Gripper elements 36 vertical recesses in cover 35 for 17

Component in stations 1 -7 37 coupling joint for 35 coupling element on 3 38 coupling rod for coupling element on 2 push rod control vertical adjusting screw for 13 39 fork element on 38 horizontal fixing screw for 40 axis of 37

13 41 Coupling cross member for fork arm of 13 gripper bars

upward 42 vertical recesses in projection of 12 41 for 13

longitudinal groove in 2 for 3 43 support element for 41 downwardly open 44 guide cylinder of 43 guide groove in 10 for 2 45 coupling joint for 41 sliding plate 46 axis of 45

Piston of 5 47 coupling rod for Grab bar control 33 'feed path

8 carrier plate of 34 'feed lever,

Transfer unit gear lever

9 upper tool plate 35 'motor, servo motor

0 lower die plate 36 'reduction gear

1 guide column between 49 37 'worm gear,

and 50 curve rib

2 redirection from 38 to 38 'transfer gear,

Gear lever cam gear

3 Redirection from 47 to 39 'drive hub

Gear lever 40 'worm

4 gear levers from 41 'housing

Push rod control 42 'stub shaft

5 gear levers from 43 'housing cover

Gripper bar control 44 'axis of rotation of 34'6 gears for push rods 45' cam roller

7 gear for gripper bars 46 'axis of 45'

8 common drive axle 47 'bearings of 45'

from 56 and 57 48 'gear-side arm from 34'9 axis from 54 49' transfer-side arm from 34'0 axis from 55 50 'upper housing

1 curve section on 58 for 54 5T seal

2 corner section on 58 for 55 52 'runners

3 cam arm of 54 53 'flank of 40'

4 rib on 61

5 Curve arm from 55 G1 gripper bar position 16 Curved rib to 62 G2 gripper bar position 27 longitudinal direction G3 gripper bar position 38 transverse direction G4 gripper bar position 40 curved area from 26 G5 gripper bar position 5

V Offset between 2 and 3 'transport rod, cf. 2/3 F travel

1 'press

2 'angle encoder

Claims

PATENT CLAIMS

1. Device (1) for the clocked longitudinal transport of workpieces (11) between at least two processing stations in a transfer press, characterized in that

the device (1) has a first (2) and a second (3) exclusively longitudinally displaceable control element as a control group (2, 3) on at least one side, the two control elements (2,3) being mounted so as to be displaceable relative to one another in an exclusively longitudinal direction are, and both control elements (2,3) are driven via a common shaft (58), with the first control element around a gripper rod (2) for the longitudinal transport of the workpieces (11) between the

Is processing stations, and wherein in the gripper bar (2) at least two in the longitudinal direction by the distance between the

Processing stations offset gripper elements (4) are mounted, which can only be moved in the transverse direction;

and wherein the second control element is a push rod (3) which forcibly controls the transverse movement of the at least two gripper elements (4).

2. Device (1) according to claim 1, characterized in that the

Push rod (3) is slidingly mounted in or on the gripper bar (2) at least in sections, preferably in a longitudinal groove (18), which is preferably at least partially open at the top and / or is partially closed by covers (10).

3. Device (1) according to one of the preceding claims, characterized in that the push rod (3) and gripper rod (2) are moved via two cam gears (56,57) driven by the common shaft (58), wherein preferably the two cam gears ( 56,57) produce essentially the same movement with phase shift.

4. Device (1) according to one of the preceding claims, characterized in that the gripper elements (4) have at least one recess or passage opening open in the vertical direction in the form of a backdrop (26) and that the push rod (3) in each case at the position of the corresponding gripper element (4) engages in this gate (26) to control the transverse movement of the gripper elements (4)

Has extension or pin (30),

or that the push rod (3) has at least one recess or passage opening open in the vertical direction in the form of a gate at the position of the corresponding gripper element (4), and that the gripper elements (4) force the transverse movement of the gripper elements (4) into this gate ) controlling intervening

Have extension or pen.

5. Device (1) according to claim 5, characterized in that the link (26) in the gripper elements (4) each have a first area (27) for retracted gripper element (4) and a second area (28) for extended gripper element (4 ) and a displacement area (29) connecting these two areas, the first area (27) in the gripper element (4) being arranged in the transverse direction closer to the workpiece (1 1) than the second area (28), and the displacement area (29) is designed as a linear or curved, in particular S-shaped connection channel or connection passage opening.

6. Device (1) according to one of the preceding claims, characterized in that the device on both sides of a longitudinal row of processing stations such first (2) and second (3)

Has controls, and where

either the transversal movement of the respective transversely opposite gripper elements (4) are necessarily controlled mirror-symmetrically with respect to the workpiece position

or wherein a spring-loaded gripper (5) is only arranged on one side of the workpiece, and an unsprung gripper (6) on the opposite side, and the transverse movement of the transport means or gripper elements (4) arranged on opposite sides of the workpiece is not necessarily mirror-symmetrical with respect to the workpiece position is controlled, wherein the control of the transverse movement is preferably so asymmetrical that the impact speed of the sprung gripper on the part is lower than that of the non-sprung gripper.

7. Device (1) according to claim 6, characterized in that it is provided for the transport between at least two, preferably 2-5 or 2-4 longitudinal rows of processing stations of the same transfer press, and a number larger by one of the first ( 2) and second (3) control elements than the number of rows of processing stations, and the first control elements (2) arranged between rows of processing stations support gripper elements (4) protruding in both transverse directions and the second control elements (3) preferably simultaneously support the gripper elements (4) compulsorily control in both transversal directions at the same time, the slotted links (26) in the gripper elements (4) projecting in different transversal directions preferably being designed mirror-symmetrically with respect to the longitudinal direction.

8. The device according to claim 7, characterized in that the first control elements (2) arranged between rows of processing stations have transversely extending through openings (9) in which the gripper elements (4) or gripper carriers (7) of gripper elements (4) are displaceably mounted , and wherein gripper elements are alternately mounted in the one and the other transverse direction in the longitudinal direction.

9. Device according to one of the preceding claims 6-8, characterized in that the first control elements (2) of the parallel control groups (2, 3) are controlled in their movement via a common transversely extending coupling cross member (41) for the gripper bars, and the second control elements (3) are controlled via a common transversely extending coupling cross member (35) for the push rods, and the coupling cross member (41) for the gripper bars, preferably connected to a cam mechanism (57) for the gripper bars via at least one coupling rod (47) and the coupling cross member for the push rods is connected to a cam gear (56) for the push rods, preferably via at least one coupling rod (38),

wherein the movement of the transport means (4 ', 1) in the longitudinal direction preferably takes place via at least one external drive (35'-37') synchronized with the movement of the press (3T), and the external motor drive (35'-37 ') via a cam gear (38 ', 56,57) with at least one by this driven feed lever (34 ', 54, 55), which moves the transport means (4', 1) back and forth in the longitudinal direction, without reversing the rotation of the external drive (35 '), and wherein the at least one feed lever (34', 54, 55) on its gear-side arm (48 ') for coupling to the worm (40') on the runner (52 ') of the cam gear (38', 56, 57) has at least two cam rollers (45 '), these Cam rollers (45 ') roll on the opposite flanks (53') of the worm (40 ') which are axial with respect to the axis of the rotor (52').

10. Device (1) according to one of the preceding claims, characterized in that at least one of the gripper elements (4) itself or on a gripper pin has a fork-shaped and / or curved gripping area (33) facing the tool for at least partially surrounding the workpiece, wherein the gripping area (33) is preferably adapted to the radius of the workpiece in the corresponding transport section,

or that at least one of the gripper elements (4) has an essentially planar gripper tip (34) facing the workpiece,

gripper elements (4) which are preferably opposite with respect to the workpiece and gripping the same tool have a substantially planar gripper tip (34) on one side and a fork-shaped and / or curved gripping area (33) on the other side.

11. Device (1) according to one of the preceding claims, characterized in that at least one of the gripper elements (4) has a gripper carrier (7) which is mounted exclusively transversely displaceably in the gripper rod (2), and in this gripper carrier (7) displaceably has a gripper pin (5) which is preferably elastically clamped against the workpiece, preferably via a spring, in particular a spiral spring (25), or via compressed air or an elastomer spring, the return preferably being configured to be adjustable

or that the workpieces (11) between the processing stations are gripped from both sides with a gripper (4) each, transported in the gripped state in the longitudinal direction to the next processing station and released again in the next processing station, and that at least one of the grippers (4) is sprung and with an elastic restoring force against the workpiece (11), wherein the suspension of the at least one gripper (4) is preferably formed by an elastic spring element (25), this spring element preferably being formed by a leaf spring, compressed air, a spiral spring or an elastomer spring.

12. Device (1) according to one of the preceding claims, characterized in that, depending on the corresponding processing stations, the respective workpiece contacting areas of the gripper elements (4) or the gripper pins (5) mounted in a gripper carrier (7) in different vertical directions Are arranged height, preferably in that the gripper elements (4) or the gripper pins (5) have two horizontal and a vertical section connecting them.

13. A method for transporting workpieces (11) between different processing stations of a transfer press, characterized in that at least one device according to one of the preceding claims is used for the transport between the stations,

preferably in the form of a method for the step-by-step production of workpieces, in particular starting from a flat, strip-shaped starting material, preferably made of metal, particularly preferably steel or aluminum, using a device according to one of the preceding claims, wherein, preferably after a first punching step and a following first forming step the workpiece (11) is gripped at least once from both sides by a pair of grippers and transported to a subsequent processing station, and further preferably

either both grippers (5, 6) are spring-loaded, and the transverse movement of the transport means consists at least partially or exclusively in that the workpieces (11) are pushed by the processing tool at this processing station against the spring force of the grippers to hold them,

or only one of the grippers (5, 6) is spring-loaded, and the transverse movement of the transport means or gripper elements (4) arranged on opposite sides of the workpiece (11) is not necessarily controlled mirror-symmetrically with respect to the workpiece position, with the control of the transverse movement preferably being so asymmetrically takes place so that the impact speed of the sprung gripper (5) on the part is lower than that of the non-sprung gripper (6).

14. Transfer press with a device according to one of the preceding claims, preferably a transfer press with several rows of processing stations offset in the transverse direction.

15. Use of a device according to one of the preceding claims in a transfer press, preferably a transfer press with several rows of processing stations offset in the transverse direction.

16. Workpiece (1 1), in particular cup-shaped, stamped and reshaped workpiece (1 1), preferably made of metal, produced using a device according to one of claims 1-12 or 14 or in a method according to claim 13.