EP2233221A2 - Punching device for a progressive die punching machine for metal punched parts - Google Patents

Abstract

The machine has a frame for supporting a lower part (2), and an upper part fastened to a horizontal portal. The portal is moved upward and downward along vertical guides, where the lower part has a horizontal plate (8) for mounting a supply and cutting station (12) for metal strips, punching and pulling stations (13, 13', 13'', 13''') and a discharging station (14). Gripping claws (11, 11', 11'', 11''') are arranged in free place between the stations during processing of a punch press, where the stations are arranged along a circular path and provided with matrices.

Description

The present invention relates to a punching device for a follow-cut punching machine for the production of metal stamped parts according to the preamble of patent claim 1.

In the case of punching metal stamped parts, the metal part is processed in a series of workstations which are each provided with at least one punch and one die, each of which is provided for carrying out a specific work step, for example for severing and / or folding and / or drawing or thermoforming. As the workstations pass through, the metal part changes shape until the final shape is achieved according to the design drawing.

According to the known technique of follow-cut punching, the transfer or transfer of the parts from one workstation to the next is ensured by the fact that the stamped part remains connected to the sheet-metal strip, from which it is only removed at the last workstation. It should be noted here that the term "stamp" here always a combination of one or more stamps in conjunction with its own associated die to understand.

Thus, a "simple" punch press that can perform a single punching operation has a punch and a single die, while a progressive punch press has a series of punches, each with its own die.

In the previously known follow-cut punching technique, the feed of the sheet metal strip, and thus also of the stamped part, is given by the feed device of the punch press, which advances the strip by one "step" for each punching stroke (the step being in the case of a number of more than two workstations of the follow-cut punch press is equal to the distance between one workstation and the next one).

In certain cases, because of the configuration of the stamped part, the above-described technology of the following step punching can not be used, in which the stamped part remains connected to the sheet metal strip and thus transported with it until it is cut off (cut off) only at the last work station. It may happen, for example, that certain stampings have no area in which the connection with the sheet-metal strip can remain. In such cases, the stamped part must already be separated from the band at the first workstation and then brought as a separate or independent part to the subsequent workstations.

According to the prior art, in such cases the so-called "transfer punching technology" is used in which the punching device is replaced by a series of individual stations arranged in a straight line, the transfer from one station to the next by means of a series of grippers accomplished, which are attached to a transporting arm. Such a transport system becomes an integral part of the stamping press, thus called "transfer punch press", which is a special punch press type.

In the patent literature, this particular type of punch press is known as a "transfer punch press", with punching stations arranged in a single plane for punched parts cut off from the sheet metal strip from the first work station. This is, in the sense of an example, from the EP0778094 can be seen in the gripper devices formed by gripper tongs, with an access station and with an unloading station, wherein each of the clamping devices is mounted on a suitable sliding rod, or from the DE4022560 in which the punching stations are arranged along a zig-zag course to reduce the space requirement, the gripper arms transporting the stamped parts along this path.

1. a) Notwendigkeit, Stanzpressen vorzusehen, die speziell für diese Art der Weitergabe der Stanzteile ausgerüstet sind, wodurch sie sich von den einfachen Folgeschnitt-Stanzpressen unterscheiden, die ohne besondere Vorrichtungen für den Transport der Stanzteile auskommen, weil die Stanzpresse mit einem einfachen Vorschubmechanismus ausgerüstet ist, der den Blechstreifen schrittweise vorschiebt;
2. b) Beträchtlicher Platzbedarf, weil die verschiedenen, in einer Ebene angeordneten Stanz-Stationen beachtlichen Raum benötigen.

Many applications of this transfer system are known in practice, in which the stamped parts are passed along a more or less straight-line course, whereby the disadvantages of this system can be summarized as follows:

1. a) Need to provide stamping presses that are specially equipped for this type of transfer of the stamped parts, which distinguishes them from the simple follow-cut stamping presses, which do without special devices for the transport of stampings, because the punch press is equipped with a simple feed mechanism who advances the sheet metal strip step by step;
2. b) Considerable space, because the different, arranged in a plane punching stations require considerable space.

• 1. Möglichkeit, eine gewöhnliche Folgeschritt-Stanzpresse ohne ein längs eines linear ausgelegten Pfades Transfer-System zu verwenden, womit die Notwendigkeit entfällt, verschieden ausgerüstete Maschinen (Transfer-Stanzen oder Folgeschnitt-Stanzen) haben zu müssen. Alle Maschinen, über die der Stanz-Betrieb verfügt, können somit gleich ausgerüstet sein, was bessere Auswechselbarkeit und bessere Anpassungsfähigkeit des Betriebs sicherstellt;
• 2. Verkleinern des Platzbedarfs im Vergleich mit einem Transfer-Stanzsystem mit gradlinig aufgereihten Stanz-Stationen. Geringerer Platzbedarf bedeutet kleinere Kosten;
• 3. Dank der Kompaktheit der Stanzpresse können kleinere bzw. mit weniger Stanzkräften und damit geringerem Energieverbrauch arbeitende Stanzpressen verwendet werden;
• 4. Reduktion der Stillstandszeiten für das Umrüsten der Stanzpresse für zu produzierende Stanzteile (auch Einrichtzeiten genannt) gegenüber einer linear ausgelegten Transfer-Stanzpresse. Diese Reduktion kann, wie die Praxis gezeigt hat, bis zu etwa 50% betragen.

The present invention therefore proposes to eliminate the disadvantages remaining according to the described and known transfer punching technology along a straight-line path, and in particular to achieve the following advantages over the prior art:

• 1. Possibility of using an ordinary sequential punch press without a linear path transfer system, eliminating the need to have differently equipped machines (transfer punching or progressive punching). All machines that have the punching operation can thus be equipped the same, which ensures better interchangeability and better adaptability of the operation;
• 2. Reduction of the space requirement in comparison with a transfer punching system with straight-lined punching stations. Less space required means lower costs;
• 3. Thanks to the compactness of the punch press, smaller or less punching and thus less energy consuming punch presses can be used;
• 4. Reduction of downtimes for the conversion of the punch press for punched parts to be produced (also called set-up times) compared to a linear transfer punch press. This reduction can, as the practice has shown, be up to about 50%.

All this gives a better profitability of the punching plant.

These advantages are achieved with a punching device for a subsequent punching press for metal stampings according to the preamble of claim 1, which has the special features according to the characterizing part of claim 1.

What is new and inventive, beyond the application of said transfer punching technology, on a stamping press not particularly equipped for this purpose (ie without the known transfer systems along a linear path) is the property that the cutting station and the stamping stations are along a circular path are arranged, which starts with a collection and separation station and ends with an unloading station for the finished stamped part.

Thanks to this feature of the punch press according to the invention, an ordinary follow-up punch press without linear transport systems can be used, with all the mentioned practical advantages, in particular with regard to costs.

Fig. 1

Die Stanzvorrichtung der erfindungsgemässen Stanzpresse teilweise schematisch im Aufriss dargestellt;

Fig. 2

Grundriss der erfindungsgemässen Stanzpresse, bei abgenommenem Oberteil der Stanzpresse von oben gesehen;

The present invention will be described below by way of an example of realization with reference to the corresponding figures. These show in the:

Fig. 1

The punching device of the punching press according to the invention is shown partially schematically in elevation;

Fig. 2

Floor plan of the punching press according to the invention, seen from above when the upper part of the punching press is removed;

The Fig. 1 shows the punching press according to the invention in elevation. It consists of an upper part 1 and a lower part. 2

In the Fig. 1 are the two parts 1 and 2, which together form the punching device, are shown lifted off from each other: this is the position of the punching device in its open position or rest position. It is clear that in the working position, the punching stroke, the upper part 1 lowers to the lower part 2, so that the stamp (in the Fig. 2 only one punch 3 is shown in section) can penetrate into the corresponding dies 4, which in the Fig. 2 can be seen better, showing the bottom of the punching press in plan.

Of course, the punching device 1,2 is shown on a punch press, which is not shown here for the sake of clarity, and because it is a conventional punch press type comprising a base 2 supporting frame, a horizontal portal on which the upper part. 1 the punching device is attached, as well as vertical guides along which the portal can move upwards (for opening the punching device) and downwards (for closing the punching device during the punching stroke), and the required movement and control mechanisms for the portal. All these movements are in the Fig. 1 indicated by the double arrow f itself, which indicates the movements of the upper part of the punching device upwards and downwards.

The upper part 1 of the punching device according to the invention consists of a substantially horizontal plate 5, on which the punch 3 in a well-defined arrangement resulting from the positions of the dies 4, which are fixed in the lower part 2 of the punching device, and, as explained later is a basic aspect of the present invention, as well as four guide elements 6 (one for each corner of the plate 5) whose purpose it is to guide the plate exactly when lowering on the lower part 2 of the punching device. These guide elements 6, also called pillars, penetrate into the bushings 7 (also four and tubular) and guide the upper part 1 very precisely vertically relative to the lower part 2.

It should be emphasized that with open punching device 1, 2, the columns 6 do not necessarily emerge from the bushes 7, as in the Fig. 1 is shown, but also can remain in it.

For the understanding of the present invention is the Fig. 2 showing the bottom part 2 of the punching device with the top removed in plan view.

In the Fig. 2 corresponds to the horizontal plate 8 of the lower part 2 of the punching device in shape of the plate 5 in the upper part 1, wherein through the center of the axis of rotation 9 of an arm star 10 extends, which is provided with gripper claws 11.

• eine Speise- und Abschneide-Station 12 für den Metallstreifen;
• vier Stanz- oder Ziehstationen 13, 13', 13", 13"' sowie
• eine Entladestation 14 für das fertige Stanzteil.

On the plate 8 are then attached:

• a feeding and cutting station 12 for the metal strip;
• four punching or drawing stations 13, 13 ', 13 ", 13"' and
• an unloading station 14 for the finished stamped part.

The processing stations 12, 13, 13 ', 13 ", 13"' have matrices 4, each of which is designed for the operation to be performed in cooperation with the corresponding punch 3. Each processing station is thus equipped with a punch and a die which are different from those of the preceding station, so that the continuous deformation of the stamped part is performed.

The processing stations 12, 13, 13 ', 13 ", 13"' and 14 are arranged according to the invention along a circular path which begins with a loading and cutting station 12 and ends with an unloading station 14. In the charging station 12 while the stamped part is separated or cut from the metal strip 15 and thus becomes an independent part, which at best also experiences a first deformation by pulling during the separation, and thus, after it has been gripped by the gripper jaw 11 of the corresponding arm of the arm star 10, can be transported to the next processing station 13 , To perform this operation, the arm star 10, starting from his in the Fig. 2 shown at first a rotational movement about the center of the circular path from, in the counterclockwise direction, over an angle corresponding to half the angular distance between two successive arms of the arm star 10, so that the gripper claw 11 over the separated in the processing station 12 part located. Then, the claw 11 suitably grips the part and the arm of the star-shaped arm 10 rotates clockwise through an angle corresponding to the angular distance between two consecutive arms of the arm star 10, so that the part is in coaxial coincidence with the processing station 13 is brought. Then, the arm star 10 returns to its original position by making a counterclockwise rotation through an angle equal to half the angular distance between two successive arms of the arm star 10.

This process repeats as often as necessary to bring the finished part to the unloading station 14, where the part is released from the claw 11 ^{IV of} the corresponding arm of the arm star 10 and transported away on a chute 16.

The number of arms of Arm Star 10 (in the Fig. 2 11 to 11 ^IV ) depends on the number of processing stations provided along the circular path, and is always equal to this number minus one.

In the in the FIGS. 1 and 2 In the illustrated case of an implementation of the present invention, which may be considered as a preferred case for many practical applications, six processing stations 12, 13, 13 ', 13 ", 13"' and 14 are provided which are angularly spaced from one another by 60 ° station arranged to the other. In this case, the arm star 10 has five arms, between two of which - those cooperating with the loading and unloading station 12 and the unloading station 14 - the angular distance is 120 °.

The number of work stations, and thus the corresponding design of the arm star 10, can of course vary within fairly wide limits dictated primarily by the dimensions of the support plates 5 and 8 and the dimensions of the parts to be produced, always within the scope of the present invention ,

The described alternating rotational movement of the arm star 10 (a type of pilgrim step movement) can be accomplished in various ways, the classical solution of which is accomplished by means of an appropriately controlled stepping motor, a technique familiar to any person skilled in the art.

In the FIGS. 1 and 2 is, merely in the sense of an example, a drive motor 17 for the arm star 10 shown, which acts via a reduction gear 18 and a camshaft 19. However, this arrangement is not part of the inventive idea and is left to the creativity of the designer.

The present invention has been described here on the basis of a vertical punch press, in which the upper part 1 of the punching device is lowered onto the lower part 2 in a vertical movement. This is a preferred way of realizing the inventive concept, as it allows the use of normal punching presses with vertical lifting movement. It should be emphasized here, however, that the present invention can also be applied independently of the particular arrangement of the plane in which the circular path of the processing stations is designed, for example on stamping presses in which the lifting movement of the punching in the horizontal or similar (inclined) direction he follows.

Earlier it was noted that the access type of gripper jaws 11, 11 ', 11 ", 11"', 11 ^{IV of} the arm star 10 on the stamped part depending on the shape of the can be different to be produced stamped part. Thus, for example, according to a preferred embodiment of the present invention (not shown in the figures), the gripper jaws 11,... 11 ^{IV are} equipped with pliers which mechanically grasp the stamped part, wherein according to a further preferred embodiment of the present invention, the pliers are pneumatic or hydraulically operated.

A further preferred embodiment of the present invention then provides that the gripper jaws 11, 11 ', 11 ", 11"', 11 ^IV are equipped for the metallic stampings with suction cups, which access by means of pneumatic suction, or by means of magnetic attraction.

All of these specific embodiments of the gripper jaws 11, 11 ', 11 ", 11"', 11 ^IV and other conceivable solutions are available to those skilled in the art who selects them according to the intended use of the inventive technology described herein.

The advantages of the present invention have already been described above as the purpose of the invention, so that they need not be further explained here. Adaptability of the work process, small footprint, lower energy requirements, short downtimes to adapt the conventional punch press, etc., are all factors that affect the economics of the production of metallic stampings from a sheet metal strip; Advantages achieved in particular by the arrangement that the processing stations are arranged along a circular path, unlike along a linear path according to the known state of the art of transfer punching technology.

List of reference numerals used in the figures

1

Top part of the punch press

2

Lower part of the punch press

3

stamp

4

die

5

Shell horizontal shell 1

6

Leadership or pillar

7

Rifle

8th

Bottom horizontal panel 2

9

axis of rotation

10

Arm star

11, 11 ', 11 ", 11"', 11 ^IV

gripper claw

12

Loading and separating station

13, 13 ', 13 ", 13"',

Punching or drawing station

14

unloading

15

Sheet metal strip (band)

16

transport slide

17

engine

18

Reduction gear

19

camshaft

Claims (7)

Punching device for a follow-up punching press for the production of metal stampings from a sheet metal strip (15), from which the stamped part is formed in successive processing steps by means of transfer from one processing station to the next, and in which is used by the known transfer technology, the providing that the stamped part at the first processing station (12) is separated from the sheet metal strip (15), which is a station for feeding and separating, and / or folding, and / or drawing,
characterized in that
the processing stations of the punch press (12, 13, 13 ', 13 ", 13"', 14) are arranged along a circular path which starts with a feed and tear station (12) and ends with an unloading station (14), and that
the transfer of the stamped part from one processing station to the next is accomplished by means of an arm star (10) rotating about an axis passing through the center of the circular path and perpendicular to the plane passing through the matrices (4) of the processing stations (4). 12, 13, 13 ', 13 ", 13"', 14) of the punching press is defined, and which is provided with the gripping jaws (11, 11 ', 11 ", 11"', 11 ^IV ), whose arrangement is selected in that the individual gripping claws (11, 11 ', 11 ", 11"', 11 ^IV ) lie in free space between two processing stations (12, 13, 13 ', 13 ", 13"', 14) during the processing during the punching stroke wherein the arm star (10) returns after each transfer operation with the stamped part from one processing station to the next to its initial position. Punching device for a follow-cut punch press according to claim 1,
characterized in that
the plane in which the circular path of the processing stations (12, 13, 13 ', 13 ", 13"', 14) lies is a horizontal plane. Punching device for a follow-cut punch press according to claim 1,
characterized in that
along the circular path except the feed and removal station (12) and the unloading station (14) four follow-punch stations (13, 13 ', 13 ", 13"') are arranged, and that the arm star (10) five arms , wherein between the first and the last arm is an angular distance of 120 °, while the angular distance between the other arms is 60 °. Punching device for a follow-cut punch press according to claim 1,
characterized in that
the gripping jaws (11, 11 ', 11 ", 11"') are provided with pliers which mechanically grasp the stamped parts being processed. Punching device for a subsequent punching press according to claim 3,
characterized in that
the gripping jaws (11, 11 ', 11 ", 11"') are actuated pneumatically or hydraulically. Punching device for a follow-cut punch press according to claim 1,
characterized in that
the gripping jaws (11, 11 ', 11 ", 11"') are provided with suction cups, which grip the stamped parts with pneumatic suction action. Punching device for a follow-cut punch press according to claim 1,
characterized in that
the gripping jaws (11, 11 ', 11 ", 11"') detect the stamped parts with magnetic attraction.

Images