EP1238723B1 - Device for bending plates - Google Patents

Description

The invention relates to a device according to the preamble of the first claim (see, for example DE-C-940525 ).

The folding of sheets is well known and is usually carried out on presses. In this case, a bending jaw (shaping jaw) arranged in the upper tool is used, which bends the sheet metal area to be bent near the bending line.

Be bent with such a device sheet metal parts, where the mold jaw can not attack evenly on the bending line, the abzukantende sheet metal part is not uniformly deformed or even deformed. It then forms waves or bumps that can not be completely eliminated. The same disadvantages occur when, because of the existing shape of the sheet metal part to be folded off, in the case of translationally movable shaping jaws, these bending edges can not run over far enough.

Object of the present invention is to remedy this situation and to propose a method and an apparatus for performing the method by which the aforementioned disadvantages are avoided.

This object is achieved by the features of the first claim.

In contrast to the previously existing devices is now proposed that the mold jaw is pivotally guided in a housing. Thus, a fold can be made evenly at the bend line. Also already hereby converted sheet metal areas can be folded, which would otherwise be deformed in a translational movement of the mold jaw. This makes it possible to produce sheets, e.g. in automobile body construction, reshape, in which previously occurred at the bending bumps or waves that could not be removed or only very labor intensive.

The subclaims 2 to 13 describe advantageous embodiments of the invention.

Figur 1

einen schematisierten Querschnitt durch das erfindungsgemäße Abkantwerkzeug an einer Presse;

Figur 2

die Anordnung nach Figur 1 in der Endstellung;

Figur 3

eine perspektivische Prinzipdarstellung der Formbacke im Gehäuse mit Schlittenführung;

Figur 4

die Ansicht gemäß Figur 3 mit einseitig geöffnetem Gehäuse;

Figur 5

eine perspektivische Darstellung des Rotationskörpers mit Schlittenführung;

Figur 6

die Ansicht nach Figur 5 in der Endstellung;

Figur 7

die Ausgangsstellung der Schlittenführung mit Schlitten;

Figur 8

die Endstellung der Anordnung gemäß Figur 7.

In the following the invention will be explained in more detail with reference to a selected example. They show:

FIG. 1

a schematic cross section through the bending tool according to the invention on a press;

FIG. 2

the arrangement of Figure 1 in the end position;

FIG. 3

a perspective schematic representation of the mold jaw in the housing with carriage guide;

FIG. 4

the view of Figure 3 with unilaterally open housing;

FIG. 5

a perspective view of the rotating body with carriage guide;

FIG. 6

the view of Figure 5 in the end position;

FIG. 7

the starting position of the carriage guide with carriage;

FIG. 8

the end position of the arrangement according to FIG. 7

In Figure 1, the arrangement according to the invention is shown schematically in its initial position, i. before the beginning of the bending process with the tool still open. Here, 1 denotes a tool frame in a press, with 2 a movable press lower tool and with 3 an associated, also movable press upper tool.

On the press lower tool, a rotary body 4 in a housing 5 is visible in section. The rotation body carries a mold jaw 4.1. This serves to accommodate the bent sheet metal area and abzukanten.

On the rotary body 4, a lever 6 is arranged, which cooperates with a carriage 7. The carriage 7 is guided in slide guides 8 on the tool frame 1.

The carriage 7 is actuated by a slave cylinder piston arrangement 9, which is likewise fastened to the tool frame 1.

The actuation of the slave cylinder piston unit 9 via a donor cylinder piston unit 10 which is fixed to the tool frame 1. The two cylinder-piston units are connected via a hose connection 11.

To actuate the encoder-cylinder piston unit 10, a plunger 15 is provided on the press upper tool 3 in such a way that when the tool is closed, the plunger 15, the piston rod 10.1 of the donor cylinder piston unit 10 just touched, without them to move.

Also shown in Figure 1 is a Nachformstempel 12, which is also attached to the tool frame 1 and cooperates with the rotary body 4 when it has reached its end position (Figure 2).

The sheet metal which is to be further shaped at the same time is also shown in FIG. 1 and denoted by 13, wherein the region (deep-drawn) which has already been folded in a previous operation is designated by the reference numeral 14.

In Figure 2, the end position of the press is shown. In this case, the sheet-metal area 14 to be bent was bent by pivoting the rotary body 4 with the shaping jaw 4.1 in the housing 5.

At the same time visible in Figure 2 that the Nachformstempel 12 holds the rotary body 4 in its final position. Thus, a subsequent springing of the rotary body 4 in its housing and thus of the folded sheet metal region 14 is prevented.

To edge the sheet metal region 14, the procedure is as follows.

After the sheet 13 has been inserted into the open press, the upper tool 3 moves downwards and that until the sheet 13 is clamped between the upper tool 3 and the lower tool 2. In this position, the plunger 15 contacts the piston rod 10.1 of the master cylinder piston unit 10th

In a further downward movement of the upper tool 3, on the one hand, the lower tool 2 is moved in the direction of the tool frame 1 and on the other hand, the piston rod 10.1 of the encoder-cylinder piston unit 10 moves downwards by the plunger 15. As a result, the hydraulic oil in the cylinder is displaced via the hose connection 11 into the slave cylinder piston unit 9. Thus, its piston rod extends and thus moves the carriage 7 in his leadership upwards. Since the carriage 7 cooperates with the lever 6, it moves in its upward movement also the lever 6 upwards, whereby the rotary body 4 is pivoted in the guide of its housing 5.

The end position is reached when the lower tool 2 rests on the tool frame 1. In this position, the Nachformstempel 12 abuts against the rotary body 4 and locks it in the final position.

In general, this is achieved by choosing a suitable transmission ratio between on the one hand between master and slave piston cylinder unit and on the other by the working paths of the carriage 7 and the press upper and lower tool (3 or 2).

In the following, the individual components according to the invention will be described in detail.

FIG. 3 shows a perspective basic view of the rotary body 4 in its housing 5. Furthermore, it is visible here that the rotary body 4 is held in its initial position by two springs 16 which protrude laterally from the housing 5 and are fastened at a suitable location on the housing 5

The Nachformstempel 12 penetrates the housing 5 and cooperates in the end position with the stop surface 4.2 on the rotary body.

FIG. 4 differs from the illustration in FIG. 3 in that the left-hand half of the housing is broken away. Thus, one of the two lateral guide surfaces of the rotary body 4 is visible. The rotary body 4 has in this example first lateral guide surfaces 17, which are formed like a circle segment. It is guided via two correspondingly configured counter guide surfaces 18 in the housing 5.

Of course, the design of the two guide surfaces depends on the bending angle and the pivoting range of the rotary body 4 in its housing 5.

An exact guidance of the rotary body 4 is further achieved by providing two further guide surfaces 19 concentric with their first guide surfaces 17, which cooperate with a further guide surface 20 fixed to the housing (FIG. 4).

In Figure 5, the housing 5 is omitted, so that the rotary body 4 is visible with its arranged on both sides guide surfaces 17 and 19.

In Figure 5, the rotating body is shown in its home position, that is, the folding operation has not yet begun.

In Figure 6, the end position of the rotating body is also shown without housing. Here is also visible how the lever 6, which is arranged on the back of the rotary body 4, cooperates with the carriage 7. In order to reduce the friction, the carriage 7 has a roller 21 which rolls on the circumference of the lever 6.

The design of the lever 6 depends on the lifting height of the slave cylinder piston unit 9 and the bending angle.

So that the Nachformstempel 12 can reach the contact surface 4.2 of the rotary body 4, the contour of the tread for the roller 21 on the lever 6 is further designed so that after completion of the bending process, the carriage 7 can move on without further movement of the rotating body 4. This comes in a further downward movement of the press lower tool 2 of the Nachformstempel 12 with the contact surface 4.2 of the rotating body in contact.

FIG. 7 shows a detail of the carriage 7 in the starting position. Here it is visible how the carriage 7 is guided in the slide guide 8 without play. For this purpose, the carriage guide 8 guide surfaces 22 to 24.

Figure 8 shows the carriage in the final position, i. at maximum retracted piston rod of the slave cylinder piston unit 9th

Claims (13)

1. A device for bending metal sheets, comprising a device for clamping the sheet and a pivotably mounted jaw (4.1) for bending the required area (14) of the sheet, wherein the jaw (4.1) is pivotably mounted in its casing (5) so as to bend around the bending line,
   characterised in that the device is a press wherein the metal sheet is clamped between a movable top tool (3) and a bottom tool (2) disposed on a tool rack (1), and the jaw (4.1) is pivotable via a carriage (7) hydraulically driven by a slave cylinder-piston unit (9) and operatively connected to a master cylinder-piston unit (10) on the rack (1) and actuated by the top part of the press.
2. A device according to claim 1, characterised in that the jaw (4.1) fully receives the area (14) of the sheet for bending.
3. A device according to claim 1 or claim 2, characterised in that the jaw (4.1) is fastened to a rotary member (4) guided in the casing (5) and with a lever (6) fastened to its back.
4. A device according to any of claims 1 to 3, characterised in that the casing (5) is fastened to the bottom tool (2) of the press.
5. A device according to claim 3 or claim 4, characterised in that the casing (5) has lateral guide surfaces (18) which co-operate with guide surfaces (18) on the rotary member (4).
6. A device according to any of the preceding claims 3 to 5, characterised in that the rotary member (4) is pivotable against the force of a spring (16).
7. A device according to any of the preceding claims 3 to 6, characterised in that the carriage (7) carries a roller (21) which co-operates with the lever (6).
8. A device according to any of claims 1 to 7, characterised in that the carriage (7) is movable in guide surfaces (22 - 24) fastened to the rack. (1).
9. A device according to any of claims 1 to 8, characterised in that the carriage (7) is connected to a piston rod of the slave cylinder-piston unit (9).
10. A device according to any of the preceding claims 1 - 9, characterised in that the piston rod (10.1) of the master cylinder-piston unit is actuated by a push rod disposed on the top tool (3).
11. A device according to any of the preceding claims 1-10, characterised in that the bottom tool (2) is movably mounted.
12. A device according to any of the preceding claims 1 - 1 1, characterised in that a postforming punch (12) is disposed on the rack (1) and co-operates with an abutment surface (contact surface 4.2) on the rotary member (4).
13. A device according to any of the preceding claims 3 - 12, characterised in that the lever (6) is designed so that when the bottom tool (2) stops moving, the rotary member (4) is additionally pivoted after the bending operation.

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