EP2823908B1 - Forming tool with a feeding device - Google Patents

Description

The invention relates to a tool with a feed device according to the preamble of claim 1 and a production system consisting of a press and such a tool according to claim 10.

Generic tools have long been known in the art and are used to produce stamped and / or bent parts in large quantities. Particularly in the electrical industry, such tools play a very important role in the production of contact elements of all kinds. Such a tool always consists of a stationary first mold half and a relative to this first mold half oscillating drivable second mold half. Here, the first mold half is usually the lower mold half and the second mold half the upper mold half.

Such a tool has at least two characteristic directions, namely the direction of the oscillating movement (stroke direction, usually the Z direction) and the feed direction in which the finished parts move through the tool, during which they move on a transport strip stay put. This feed direction is usually perpendicular to the stroke direction and can be referred to, for example, as the X direction. There is a feed device which conveys the parts which remain connected to a transport strip through the tool in the transport direction. Often the tool is fed with an unprocessed metal strip; In this case, this feeding device is usually formed as a pair of counter-rotating rollers, between which the unprocessed metal strip runs. In this case, at least one of the two rollers is driven by a servomotor, which is synchronized electronically with the press which drives the second mold half. After completion of a feed stroke and before the tool is fully closed, the distance between the two rollers is increased to avoid stresses in the belt (so-called "breathing"). The power transmission between the rollers and the metal strip takes place exclusively via frictional forces.

There are also tools to which pre-formed items are supplied, with the preformed items are held on a transport strip, which is usually perforated. This case can occur, for example, when the tool is used to produce two-part elements, for example two-part contact elements, in particular crimping elements. In this case, the tool has two mutually opposite, so antiparallel oriented transport directions and a mounting station on which the two-part elements are mounted from two separate parts on. Here, a separate feed device is provided for each transport direction.

• Bei einem ersten Konstruktionsprinzip einer Vorschubeinrichtung für diesen Zweck ist die Vorschubeinrichtung durch die Hubbewegung der Presse zwangsgesteuert. Die Vorschubeinrichtung weist einen Block auf, welcher eine oszillierende Bewegung parallel zur Vorschubrichtung durchführen kann. Zur Umsetzung der oszillierenden Hubbewegung der Presse in diese oszillierende Bewegung dient ein Keilgetriebe, welches die oszillierende Hubbewegung der Presse um 90° umlenkt. Der Block trägt ein Schwenkelement mit einer Nase, welche bei einer Bewegung des Blocks in Vorschubrichtung in Eingriff mit einem Loch des Transportstreifens kommt und so den Transportstreifen vorwärts schiebt. Bei einer Bewegung entgegengesetzt der Vorschubrichtung rutscht diese Nase aufgrund einer Schrägfläche aus diesem Loch heraus, so dass diese Bewegung nicht auf den Transportstreifen übertragen wird. Der Vorschub kann hierbei entweder nur bei sich öffnenddem oder nur bei sich schließendem Werkzeug erfolgen.

For the advance of the preformed items is in this case only the relatively thin transport strip available. So far, two types of feed devices are used for this purpose, which have completely different modes of operation:

• In a first design principle of a feed device for this purpose, the feed device is positively controlled by the lifting movement of the press. The feed device has a block which can perform an oscillating movement parallel to the feed direction. To implement the oscillating stroke movement of the press in this oscillating motion is a wedge gear, which deflects the oscillating stroke of the press by 90 °. The block carries a pivoting member with a nose which, upon movement of the block in the feed direction, engages a hole of the transporting strip and thus pushes the transporting strip forward. In a movement opposite to the feed direction, this nose slips out of this hole due to an inclined surface, so that this movement is not on the Transport strip is transmitted. The feed can be done either only when you open the end or only when closing tool.

A disadvantage of this design principle is that the feed length per stroke can be as large as the maximum lifting height of the press. In order to increase the productivity, however, there is often the desire to design the above-mentioned tools for producing two-part contact elements so that they have two assembly stations, where first and second items are joined together. Of course, this requires correspondingly large feed lengths, which make correspondingly large lifting heights necessary. However, large lifting heights are problematic for mechanical reasons and usually necessitate a reduction of the clock frequency. Of course, reducing the clock frequency is contrary to the goal of increasing productivity.

Also the GB 2 063 137 A describes a feed device, which is forcibly taxed by the lifting movement of the press. Just as described above, the feed device has a block which carries a pivoting element with a nose. Here, the block is driven via a sector gear, which is coupled to the lifting movement of the press.

The second type of feed device for this purpose is essentially the same as the feed devices described above, namely, they have an opposite pair of rollers between which the transport strip runs. Again, at least one roller is driven by a servomotor, which is synchronized with the press. Here there is no connection between the amplitude of the lifting movement and the maximum feed length and the feed can take place both with the tool opening and closing. Nevertheless, even here no arbitrarily long feed lengths can be realized. This is due, in particular, to the fact that the power transmission takes place exclusively via frictional forces. If you want to achieve a large feed, then large accelerations are necessary. However, these can only be achieved with correspondingly high clamping forces. However, excessive clamping forces can, especially in context With high accelerations, lead to a deformation of the transport strip, but this must be avoided at all costs. Thus, the achievable at high cycle speeds feed length is limited even with this type of feed devices.

On this basis, the present invention has the object to provide a tool available, with the large feed lengths can be achieved at the same time high numbers of cycles.
This object is achieved by a tool having the features of claim 1.
A production plant consisting of a press and such a tool is specified in claim 10.

According to the invention, the two principles described above are combined with each other, wherein the actual feed mechanism is formed as in the first design principle described above, for their drive, however, an electric motor, in particular a servomotor, is used. The coupling takes place via a connecting rod. This means that for the advancing movement, the rotational movement of an electric motor is the cause, but the transport strip is not driven by a rotational movement, but via a nose, which performs an oscillating movement parallel to the feed direction and which in a movement in the feed direction into engagement with a hole of the perforated transport strip comes and is not in engagement with such a hole in a movement in the opposite direction. This nose is part of a feed element, which is connected via a connecting rod with the drive shaft of the electric motor. The feed force is introduced exclusively via the nose in the transport strip, wherein the nose is in this case in a hole of the feed strip.
Thus, one achieves an independent of the lifting movement, clamping force-free, slip-free feed, which can work both when opening tool and closing tool. This allows compared to the prior art significantly larger feed paths per clock, the feed can be done both during opening and during closing of the tool.

According to claim 2, the nose preferably has a sloping rear side, so that it slides out of the hole of the transport strip against the feed direction "on its own" upon retraction of the feed element and thus comes out of engagement with the transport strip.

According to claims 3 and 4, the feed element is preferably constructed in at least two parts, wherein the element which is directly connected to the connecting rod, can perform only an oscillating movement parallel to the feed direction. At least one pivoting element, which carries the nose, is movably held on this oscillating element. Preferably, this pivoting element is held pivotably about an axis on the oscillation element. As a result, the two necessary movements of the nose are decoupled from each other, which greatly simplifies the construction.

According to claim 5, the oscillating element can carry at least two pivot elements, whereby load on each individual nose is reduced.

Further preferably, the drive axle of the electric motor performs an oscillating movement, whereby it can be avoided in particular that the connecting rod must be designed as a crank gear.

Figur 1

eine stark schematisierte Darstellung eine Werkzeuges,

Figur 2

eine detaillierte Darstellung einer Vorschubeinrichtung und vorgeformte Einzelteile, welche an einem gelochten Transportstreifen gehalten sind in einer ersten Stellung der Vorschubeinrichtung,

Figur 3

das in Figur 2 Gezeigte in einer zweiten Stellung der Vorschubeinrichtung,

Figur 4

das in Figur 3 Gezeigte mit einer Detailansicht,

Figur 5

das Schwenkelement und den Transportstreifen mit vorgeformten Einzelteilen aus Figur 4 in einer weiteren Ansicht,

Figur 6

das in Figur 5 Gezeigte in einer weiteren Ansicht,

Figur 7

eine aus einer Presse und einem in dieser Presse aufgenommenen Werkzeug bestehende Produktionsanlage, wobei sich die zweite Werkzeughälfte in ihrem oberen Totpunkt befindet,

Figur 8

das in Figur 7 Gezeigte, wobei sich die zweite Werkzeughälfte in ihrem unteren Totpunkt befindet und

Figur 9

das in Figur 8 Gezeigte bei sich öffnendem Werkzeug.

The invention will now be explained in more detail by means of embodiments with reference to the figures. Hereby show:

FIG. 1

a highly schematized representation of a tool,

FIG. 2

a detailed representation of a feed device and preformed items which are held on a perforated transport strip in a first position of the feed device,

FIG. 3

this in FIG. 2 Shown in a second position of the feed device,

FIG. 4

this in FIG. 3 Shown with a detail view,

FIG. 5

the pivoting element and the transport strip with preformed items from FIG. 4 in another view,

FIG. 6

this in FIG. 5 Shown in another view,

FIG. 7

a production plant consisting of a press and a tool incorporated in this press, with the second mold half in its top dead center,

FIG. 8

this in FIG. 7 Shown, with the second tool half is in its bottom dead center and

FIG. 9

this in FIG. 8 Shown by opening tool.

In order to understand the invention better, will first be with reference to the FIG. 1 which is very schematic and of little detail, describes a tool which serves to produce contact elements assembled from two individual elements. Such a tool is an important application of the present invention, but not the only one possible.

The first mold half 10 is the stationary, lower mold half, while the second mold half is drivable by means of a press (not shown), so that it performs an oscillating stroke movement in the Z direction. The tool has two transport paths 12, 14 extending in the X direction, which are shown schematically as wide grooves in the first tool half 10. These two transport paths 12, 14 are connected to a mounting station by means of a cross-connection 16, which is also shown schematically as a groove here. This groove extends in the Y direction, ie perpendicular to the direction of the transport paths and perpendicular to the direction of the lifting movement. In the cross-connection 16, a slider 17 is arranged, which is part of a transverse thrust device.

The tool is supplied at the first end 12a of the first transport path, a metal strip and from this metal strip first items are formed on the way to the assembly station. As a feed device, which promotes the items in a first transport direction, namely the X direction, can serve a conventional feed device with two counter-rotating rollers, as already explained above.

Furthermore, preformed individual parts are fed to the tool at the first end 14a of the second transport path 14, which are connected to a perforated transport strip. These preformed individual parts are conveyed by means of a feed device according to the invention in a second transport direction, namely in the -X direction, the assembly station, where they are joined together with the first items.

The feed is synchronized in each case with the lifting movement of the second mold half, namely with the tool open.

• Die Figur 2 zeigt die Vorschubeinrichtung 20 für den zweiten Transportweg 14. Diese dient dazu, bereits vorgeformte Einzelteile 40, welche an einem gelochten Transportstreifen 42 gehalten sind, dem Werkzeug zuzuführen und in diesem zu transportieren, so dass sie zur Montagestation gelangen können. Die Vorschubeinrichtung 20, welche ein Teil der ersten Werkzeughälfte ist, also unmittelbar mit einem benachbarten Element der ersten Werkzeughälfte verbunden ist, weist einen Servomotor 22 auf, dessen Antriebsachse 23 sich parallel zur Hubrichtung, also in Z-Richtung erstreckt. Mit dieser Antriebsachse 23 ist drehfest ein Schwenkhebel 24 verbunden. Ein erstes Ende eines Pleuels 26 ist mit diesem Schwenkhebel 24 verbunden und erstreckt sich im Wesentlichen parallel zu den Vorschubrichtungen, nämlich in -X-Richtung. Das zweite Ende dieses Pleuels 26 ist an einem Block 32 eines Vorschubelementes 30 angeschlossen. Die beiden Achsen des Pleuels 26 erstrecken sich in Z-Richtung. Der Block 32 dient als Oszillationselement und ist derart an der ersten Werkzeughälfte 10 gehalten, dass er ausschließlich parallel zur X-Richtung in einer Oszillationsbewegung bewegbar ist. Der Block 32 trägt zwei Schwenkelemente 34, 34'. Diese sind jeweils über eine Achse 37, 37' mit dem Block 32 verbunden, so dass die Schwenkelemente bezüglich der Oszillationsbewegung mit dem Block 32 gekoppelt sind. Die Achsen 37, 37' befinden sich jeweils an einem hinteren Ende der Schwenkelemente 34, 34' und erstrecken sich in Y-Richtung, also senkrecht zur Hubrichtung und senkrecht zur Vorschubrichtung. Somit können die vorderen Enden der Schwenkelemente 34, 34' eine Schwenkbewegung durchführen, welche im Wesentlichen parallel zur Hubrichtung ist. Am vorderen oberen Ende jedes Schwenkelementes 34, 34' ist eine Druckfeder 38, 38' vorgesehen. Das dem Schwenkelement abgewandte Ende dieser Druckfeder 38, 38' ist jeweils mit dem Block 32 verbunden, so dass die Druckfeder 38, 38' das vordere Ende des jeweiligen Schwenkelements 34, 34' in -Z-Richtung in Richtung des Transportstreifens 42 drückt. Am gegenüberliegenden unteren, vorderen Ende jedes Schwenkelementes 34, 34' ist eine Nase zum Eingriff in ein Loch des Transportstreifens 42 vorgesehen. Dargestellt sind in den Figuren 5 und 6 sowie in der Detailansicht der Figur 4 die Nase 36 des ersten Schwenkelementes 34. Die Vorderfläche, das heißt die Fläche, welche in die Transportrichtung zeigt, hat die Form der Mantelfläche eine Halbzylinders mit einem Durchmesser, welcher etwas geringer als der Durchmesser der Löcher 42a der Transportstreifens 42 ist. Die Achsen der Halbzylinder erstrecken sich jeweils in Z-Richtung (Hubrichtung). Die Rückseite der Nasen verläuft jeweils schräg derart, dass sie entgegen der Transportrichtung in Z-Richtung ansteigt.

Since the present invention exclusively deals with the feed device which advances the perforated transport strip (and thus the preformed individual parts), only this will be described below. In this case, unless otherwise stated: "feed device" is the feed device for the punched transport strip, "transport direction" is the transport direction of the glochten transport strip (and the preformed items), so in FIG. 1 the -X direction:

• The FIG. 2 shows the feed device 20 for the second transport path 14. This is used to supply already preformed items 40, which are held on a perforated transport strip 42, the tool and to be transported in this, so that they can get to the assembly station. The feed device 20, which is a part of the first mold half, that is connected directly to an adjacent element of the first mold half, has a servo motor 22, the drive axis 23 extends parallel to the stroke direction, ie in the Z direction. With this drive shaft 23 a pivot lever 24 is rotatably connected. A first end of a connecting rod 26 is connected to this pivot lever 24 and extends substantially parallel to the feed directions, namely in the -X direction. The second end of this connecting rod 26 is connected to a block 32 of a feed element 30. The two axes of the connecting rod 26 extend in the Z direction. The block 32 serves as an oscillating element and is held on the first mold half 10 such that it exclusively in parallel to the X direction in an oscillatory motion is movable. The block 32 carries two pivot elements 34, 34 '. These are each connected via an axis 37, 37 'to the block 32, so that the pivot elements are coupled with respect to the oscillation movement with the block 32. The axes 37, 37 'are each located at a rear end of the pivot elements 34, 34' and extend in the Y direction, ie perpendicular to the stroke direction and perpendicular to the feed direction. Thus, the front ends of the pivot members 34, 34 'can perform a pivotal movement which is substantially parallel to the stroke direction. At the front upper end of each pivoting element 34, 34 ', a compression spring 38, 38' is provided. The end of this compression spring 38, 38 'facing away from the pivoting element is respectively connected to the block 32, so that the compression spring 38, 38' presses the front end of the respective pivoting element 34, 34 'in -Z direction in the direction of the transporting strip 42. At the opposite lower, front end of each pivoting element 34, 34 'a nose for engagement in a hole of the transport strip 42 is provided. Shown in the Figures 5 and 6 as well as in the detail view of the FIG. 4 the nose 36 of the first pivot member 34. The front surface, that is, the surface facing the transport direction, has the shape of the surface of a half-cylinder having a diameter slightly smaller than the diameter of the holes 42a of the transporting strip 42. The axes of the half cylinders each extend in the Z direction (stroke direction). The back of the noses each extends obliquely so that it rises in the Z direction opposite to the transport direction.

The operation of the feed device is as follows: In the in FIG. 2 shown first working position (rear working position) is the pivot lever at its rear dead center: In this state, the two lugs 36 are each engaged in a hole of the transport strip 42 and are held by their compression springs 38, 38 'there. Now, with the tool open, the drive shaft 23 of the servomotor 22 is rotated by a certain angle, whereby the connecting rod 26 of the block 32 and thus the associated pivoting elements 34, 34 'are moved in the transport direction until the state FIG. 3 is reached (front working position, front dead center). In this state, the tool closes, leaving the transport strip 42 is held with the tool closed by not shown holding elements between the two mold halves. In this state, the servomotor 42 rotates the drive shaft 23 in the opposite direction by the same angle, so that via the connecting rod 26, the block 32 and thus also the pivoting elements 34, 34 'held on it are withdrawn. In this case, the lugs slide out of their respective hole 42a due to their bevelled backs 36b and, at the end of this backward movement, come into engagement with the respectively next hole in which they are pressed due to their respective compression spring. Here begins a new cycle. The feed can take place over a very long period of time within one cycle, namely during the entire time in which the transport strip is not held by the tool, ie in particular during the opening and closing tool. This is only possible with the necessary precision because the feed element 30 is connected to the servomotor 22 via a connecting-rod gear.

The FIGS. 7 to 9 show schematically a from a press 60 and a recorded in this press 60 tool existing production facility. The tool is in this case constructed as described above, wherein the first mold half 10 is connected to a stationary, lower press plate 62 and the second mold half with a movable, upper press plate 61. Upper and lower press plate are connected to each other by means of a frame 63. To drive the upper press plate 61, an electric motor 64 is provided. In operation, this electric motor rotates at a constant speed and puts the upper press plate 61 (and with it the second mold half 50) by means of an eccentric 65 in an oscillating motion.

The electric motor 64 of the press is controlled by a controller 66 of the press 60, wherein a signal return is usually provided as well. This signal return provides the controller with data that is directly related to the position of the upper press plate so that the controller "knows" the position of the upper press plate at all times. The servo motor 22 of the feed device 20 is directly or - as shown - driven indirectly via an intermediate controller 68 from the control of the press, so that the servo motor (And thus the feed device as a whole) is synchronized by the control unit 68 with the press. The servo motor performs a clocked, reciprocating motion.

LIST OF REFERENCE NUMBERS

10

first tool half

12

first transport route

12a

first end

14

second transport route

14a

first end

16

cross connection

17

pusher

20

feeder

22

servomotor

23

drive axle

24

pivoting element

26

pleuel

30

feed element

32

block

34.34 '

pivoting lever

36

nose

36a

front

36b

back

37.37 '

axis

38.38 '

compression spring

40

preformed item

42

transport strip

42a

hole

50

second tool half

60

Press

61

upper press plate

62

lower press plate

63

frame

64

Electric motor of the press

65

eccentric

66

Control of the press

68

Control unit of the servomotor

Claims (11)

1. Tool with
   a first tool half (10), and a second tool half (50) which is movable relative to the first tool half in a stroking direction, wherein the second tool half (50) can be driven against the first tool half (10) by means of a press in an oscillating stroking movement,
   at least one feeding device (20) held at the first tool half, which feeds preformed individual parts (40) which are held on a perforated transport strip (42), in a pulsed or cyclic manner in a feed direction (-X) perpendicular to the stroking direction, to the tool and then transports them onwards in the tool, wherein the feeding device (20) comprises an electric motor with a drive axle (23),
   characterized in that the drive axle (23) is connected by means of a connecting rod drive to a feed element (30) held at the first tool half, which by means of the connecting rod drive can be set into an oscillating movement in the feed direction and back, wherein the feed element comprises a nose (36) extending transversely to the feed direction for engagement in a hole (42a) of the transport strip (42), and wherein
   at least the section of the feed element, from which the nose (38) extends, can be moved relative to the first tool half against the force of at least one resetting element, which takes effect parallel to the direction of extension of the nose.
2. Tool according to claim 1, characterized in that the nose comprises a front side, pointing in the feed direction, and a rear side running obliquely relative to the feeding device.
3. Tool according to any one of the preceding claims, characterized in that the feed element comprises an oscillation element (block 32) connected to the connecting rod, capable of movement exclusively parallel to the feed direction, and a pivot element held at the oscillation element and carrying the nose.
4. Tool according to claim 3, characterized in that the pivot element is held at the oscillation element such as to be pivotable over an axis, and that the resetting element is a spring.
5. Tool according to any one of claims 3 or 4, characterized in that the oscillation element carries at least two pivot elements.
6. Tool according to any one of the preceding claims, characterized in that the drive axle of the electric motor carries out an oscillating movement.
7. Tool according to claim 6, characterized in that the connecting rod does not intersect the axial projection of the drive axle of the electric motor in any working position.
8. Tool according to any one of the preceding claims, characterized in that the electric motor is a servomotor.
9. Tool according to any one of the preceding claims, characterized in that it comprises two assembly stations at which preformed individual parts are joined together.
10. Production system, consisting of a tool according to any one of claims 1 to 9, and a press with an upper press plate (61) driven by a further electric motor (64), said plate carrying the second tool half (50), and a lower press plate (62), which carries the first tool half (10).
11. Production system according to claim 11, characterized in that, in addition, a control unit (66) is provided for the press, which at least indirectly actuates the electric motor of the feeding device, and thereby provides for synchronization between the press (60) and the feeding device.

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