EP0650782B1 - Press brake - Google Patents

Abstract

In a press brake (20) for bending workpieces (22) along a bending line (23), with an operating area (17) in front of the bending line (23), with a stop area (24) behind the bending line (23), with a drive (21) for the stroke of a bending tool (9), with a stroke-actuating device (7) which activates the drive (21) and with an interlock device to prevent the stroke-actuating device (7) from being switched on, with a stop device (26) which is arranged in the stop area (24) and has a rail (27) which can be moved and positioned perpendicular to the bending line (23) by means of a controllable drive and on which at least two stop fingers (28, 29) which can be displaced and positioned along the rail (27) by hand and fixed by means of a clamping device (42) are arranged, the position of the individual stop fingers can be changed manually without danger by virtue of the fact that a locking device is provided for the release of the clamping device (42) and in that the stop device (26) can be moved into a position in which the stop fingers (28, 29) project beyond the bending line (23) into the operating area (17) of the press brake, the switch-on interlock device is operative and the locking device for the release of the clamping device (42) is inoperative. <IMAGE>

Description

The invention relates to a press brake for folding Workpieces along a bending line with one in front of the Bending line located operating area, with a behind of the bend line, with a Drive for the lifting movement of a bending tool, with one the actuating stroke actuating device and a switch-on device for the Lift actuation device, with one in the stop area arranged stop device, the one by a controllable drive that can be moved perpendicular to the bending line Positionable rail has at least two Can be moved and positioned by hand along the rail and stop fingers which can be fixed by means of a clamping device are arranged. Such a press brake is see for example US-A-4089200.

Press brakes are in a wide variety Embodiments known. As a rule, each one Press brake a backgauge on which the workpiece to be chamfered is created before folding to be able to carry out the fold precisely. This Back stops are in the X axis, i.e. in the level of Workpiece and perpendicular to the bending line, as well as in the R axis, i.e. perpendicular to the plane of the workpiece, adjustable. This adjustment must be manual in some embodiments be carried out and is with other press brakes Can be carried out by motor, pneumatically or hydraulically. Some Press brakes have one in addition to the backgauge Front stop and possibly even side stops on the the position of the workpiece in the operating area can be determined and may even be changeable.

It is known that the backgauge is used either as one-piece stop bar or in the form of several individual Stop finger is formed. Here too, both Stop bar as well as the individual stop fingers either manually or using a suitable drive be adjusted. It is also known that at one several individual back fingers existing backgauge the individual stop fingers in the Z axis, i.e. in the direction the bending line can be adjusted, and in particular can the distance between the individual stop fingers to each other to be changed. This can also be done either via a suitable drive or manually.

In press brakes it is also known that the drive for the lifting movement of the bending tool from one Stroke actuator is activated. Is that Bending tool in its rest position, then the Lift actuation device by a Switch-on blocking device locked until it Switch-on blocking device conscious of the operator is deactivated, so that an actuation of the Lift actuation device activates the drive. To this Way an unintentional actuation of the Stroke control device can be prevented.

With simple press brakes, the individual Stop fingers are usually positioned manually. Therefor the operator must, however, from the operating area via the Reach into the stop area, what on the one hand awkward, on the other hand not dangerous.

The invention has for its object a press brake of the type mentioned in such a way that the Position of the individual stop fingers manually safe can be changed.

This object is achieved in that a Locking device for releasing the clamping device is provided and that the anchor device in a Position can be moved in which the stop fingers over the Bending line in the operating area of the press brake protrude, and that in this position, the switch-on effective and the Locking device for releasing the clamping device are ineffective.

So there is in the press brake according to the invention the bending tool in its rest position and the Stroke actuator for the drive is through the Switch-on blocking device, which is switched on or effective is locked. In this position of the bending tool the stop fingers can come out of the stop area across the bending line into the operating area are moved and are therefore more accessible to the Operator. The main advantage, however, is that the operator to move the individual Stop fingers no longer across the bend line in the Stop area must grip, so that the press brake according to the invention the individual stop fingers can be safely moved manually. Since the Switch-on blocking device for the stroke actuating device is effective, there is no risk that the Bending tool performs a lifting movement while doing so Hazards or damage caused.

Another feature essential to the invention is therein seen that when the stop fingers hit the bend line run over and intervene in the operating area, the Locking device for releasing the clamping device of the Stop finger is ineffective. Can only in this position the individual stop fingers are moved. As soon as the aligned and clamped stop fingers this Leaving position again is the locking device activated so that the clamping device is no longer released can be. Such a press brake can also from Inexperienced operating personnel can be operated quickly and safely and it requires a low level of operating knowledge because the The position of the stop fingers can be changed manually. It So there is no need to change the program on the machine be performed.

A further development of the press brake according to the invention provides before that the clamping device is formed by a clamping piece when activated, the fingers with the rail jammed. This clamp is permanently activated and is only deactivated when the stop fingers touch the Overlap the bending line and at the same time the Lift actuation device for driving the bending tool is locked by the switch-on blocking device. Through the Jamming the finger with the splint is also ensures that every single stop finger Carrier feed movement.

In a preferred embodiment, this Clamping piece at least one when activated against the rail and the stop finger pressing member or one corresponding section. This can be done easily Way the stop fingers are jammed with the rail.

According to one embodiment, the clamping piece is one Air cylinder, a magnet or the like. Formed. This Compressed air cylinder is made by applying compressed air either tensioned or released, with a high level of security is obtained by e.g. by the force of a bias spring is biased and thereby the clamping effect is achieved with the air cylinder assumes its release position by pressurization. This can also be the case with a magnet, which then has the Applies clamping effect when it is de-energized and only when Applying a voltage that releases the clamp.

The sprag can Applying a fluid in position and / or shape be changeable. The fluid can be either a gas or a gas Be liquid. When changing the position, e.g. on Wedge can be moved.

In a preferred embodiment, there is Clamping piece made of a hose that can be filled with a fluid, e.g. a compressed air hose whose cross-sectional shape and / or the position of which can be changed by the internal pressure. The clamping effect can be achieved by applying e.g. With Compressed air.

Further embodiments provide that the Switch-on blocking device has a switch which Energy supply to the stroke actuating device is interrupted. This switch is usually permanently on and must be consciously switched off in order to supply energy to the Manufacture stroke actuating device.

According to a development of the invention it is provided that the Locking device for releasing the clamping device Has switch that the energy supply to release the Clamping device interrupts, here too the switch takes off permanently in a position in which he is supplying energy interrupts, the switch only then its Switch position changes if, as already mentioned at the beginning, the stop fingers overlap the bending line and the Switch-on blocking device for the stroke actuating device is activated.

Preferably, a release device for releasing the Clamping device provided, the locking device the Release device deactivated. In this embodiment, must So the release of the clamping device is not manual be performed. The stop fingers can immediately after manually moved to deactivate the locking device become.

Figur 1

eine Ansicht einer Ausführungsform einer erfindungsgemäßen Abkantpresse;

Figur 2

eine perspektivische Ansicht einer bekannten Abkantpresse;

Figur 3

einen Prinzipquerschnitt durch eine andere bekannte Abkantpresse;

Figur 4

einen Querschnitt durch die Abkantpresse gemäß Fig. 1;

Figur 5

eine Ansicht in Richtung des Pfeils V gemäß Fig. 4;

Figur 6

eine vergrößerte Wiedergabe eines Anschlagfingers im Querschnitt; und

Figur 7

eine Draufsicht auf den Anschlagfinger gemäß Fig. 6.

Further details emerge from the following description, in which a particularly preferred exemplary embodiment is shown in detail with reference to the drawing. Show:

Figure 1

a view of an embodiment of a press brake according to the invention;

Figure 2

a perspective view of a known press brake;

Figure 3

a basic cross section through another known press brake;

Figure 4

a cross section through the press brake according to FIG. 1;

Figure 5

a view in the direction of arrow V of FIG. 4;

Figure 6

an enlarged representation of a stop finger in cross section; and

Figure 7

6 shows a plan view of the stop finger according to FIG. 6.

Figure 2 shows a perspective view of a Press brake, in particular a die press known Design type. This press brake, designated a total of 20 has a frame which, for example. Two stands 1 and 2 includes, on which an upper beam 3 is guided. Press cylinders 4 and 5, which serve as drive 21, move this upper beam 3 in the direction of arrow 6 down and in Opposite direction upwards. At least this lifting movement of the Press brake 20 is operated by a stroke actuation device 7 activated and controlled. On the upper cheek 3 is a holder 8 for a bending tool 9, e.g. one Bending die that interacts with a bending die 10. The Bending tool 9 is essentially as shown in FIG. 2 strip-shaped and the bending die 10 accordingly bar-shaped. It is by means of suitable, only schematic marked die holders 11 and 12 on the table 13 of the Press brake 20 held. 2 is a serving as workpiece 22 sheet 14 shown in Direction of arrow 18 in the press brake 20 so far is inserted until the line labeled 19 with the Bending line 23 is aligned. The workpiece 22 is in this position, then lies above line 19 Bending tool 9 with its cutting edge 15 and below the Line 19 of the workpiece 22, the bending die 10 with its V-shaped Exception 16. The one in front of the bending line 23 located area is called the operating area 17 and the rear the area of the bending line 23 as Stop area 24 defined. Holds in the operating area 17 usually the operator who the workpiece 22nd performs and enters commands on a control panel 25. Here the control panel 25 also has a switch-on blocking device on which, if activated, the Stroke actuator 7 locked so that the drive 21 or the press cylinders 4 and 5 are not actuated can. The upper cheek 3 is then in the position in FIG. 2 shown location locked.

The press brake 20 shown in FIG. 2 has one stop device 26 designed as a backgauge, which is not shown in Fig. 2, but in one other known press brake 20 shown in FIG. 3 is reproduced, is shown.

This stop device 26 shown in FIG. 3 consists essentially of a rail 27 on the two Stop fingers 28 and 29 are arranged. This Stop fingers 28 and 29 are in the direction of arrows 30 represent the Z direction, movable on the rail 27. The stop fingers 28 and 29 extend in the direction of Bend line 23 and lie on the rear edge, i.e. at the edge of the workpiece located in the stop area 24 22 on. In this way, the position of the workpiece 22 in the direction of the X axis (arrow 31). At correctly aligned workpiece 22 Switch-on blocking device deactivated, whereby the Stroke actuator 7 is unlocked so that at the actuation of the bending tool 9 a lifting movement in Direction of the double arrow 32 executes. It will Workpiece 22 folded on the bending line 23 and takes the position shown with a solid line. Away the bending tool 9 from the bending die 19, it falls Workpiece 22 in the direction of arrow 33 back to one support table, not shown.

1 shows a preferred embodiment of the Press brake 20 according to the invention with its individual Components shown. Located in operating area 17 the support bracket 34 for the workpiece 22, which is the For clarity is not shown. Below the controller 25 is a two-hand / foot switch 35 with which the stroke actuating device 7 are activated can. One is located above the stop area 24 Hydraulic system 36 for the drive 21 of the upper beam 3 of the Bending tool 9. The stop device 26 is complete from the stop area 24 to the rear (left in FIG. 1) pulled out.

The stop device 26 is shown in FIGS. 4 and 5 shown enlarged. This has a carriage 37 on a rail 38 which extends in the X direction, i.e. extends perpendicular to the bending line 23, is movable. On in this way the stop fingers 28, 29 can not workpiece 22 shown or in the direction of the bending line 23 be brought up. 4 are the stop fingers 28, 29 shown in a starting position in which they have completely retracted, i.e. with maximum distance lie to the bending line 23. Those designated 128, 129 Stop fingers are so far in the stop area 24 drove that they just did not reach the bending line 23 touch. The stop fingers designated 228, 229 are via a further drive 39, which e.g. a spindle 40 moved, in height, i.e. in the R direction. With 328, 329 designated stop fingers, the only shown broken off are also in the R axis but shifted down.

Outside the stop area 24, i.e. in operating area 17 a stop finger is also shown at 428. This The stop finger 428 assumes position when it is from the operator in the Z axis (see Fig. 5) new to be positioned. The upper cheek is located 3 in their maximum upper position and the Stroke actuator 7 is on the Locking device locked, so that even untimely actuation of the two-hand / foot switch 35 no Bending stroke can take place. The fingers 28, 29 are on one Rail 27 slidably mounted so that when they are Position as indicated by reference number 428, take, can be repositioned. this happens manually.

The stop fingers 28, 29 are via a clamping device 42, which is shown in FIG. 6, on the rail 27 fixed. Furthermore, it can be seen in Fig. 6 that the Stop fingers 28, 29 from a on the rail 27 attacking holding part 43 and a swing-out part 44 consists of a hinge 45 on the holding part 43 is attached. In the rest position shown in FIG. 6 is shown, the part 44 takes a horizontal position on. By pressurizing an expandable element 46, the part 44 can be pivoted upwards, as is is indicated in Fig. 4.

The stop finger 28, 29 takes its correct position on the Rail 27, then this is through the clamping device 42 fixed. A compressed air hose 47 is provided for this, which is formed in a substantially C-shaped Profile part 48 is arranged. Between the compressed air hose 47 and the upper leg of the profile part 48 engages Spring element 49 which e.g. via a screw on the holding part 43 the stop finger 28 is attached and its movement the rail 27 follows. The compressed air hose 47, the Profile part 48 and the spring element 49 form the Clamping device 42, the stop finger 28 on the Lock rail 27. The compressed air hose 47 pressurized with compressed air so that it inflates and that Spring element 49 between itself and the profile part 48 stuck. In this way, the stop finger 28 in fixed in position. Blowing off the compressed air from the Compressed air hose 47 is through a not shown Release device controlled. This release device is one Locking device upstream that the release device activated or deactivated. The stop finger is located 28 in the position shown in FIG. 6, in which it overlaps the bending line 23, then the locking device ineffective, so that the compressed air from the release device blown off the compressed air hose 47 and thereby the Clamping effect can be canceled so that the Stop finger 28 on the rail 27 in the desired Position can be moved. However, as is already the case mentioned above, the stroke actuator 7 for the Upper beam 3 blocked by the switch-on blocking device.

If the stop finger 28 moves out of the position shown in FIG. 6 position shown back in the stop area 24, then the locking device for the release device is activated, so that after clamping the stop finger 28 in the desired position, the air from the compressed air hose 47 can no longer be blown off. The stop finger 28 is So only in the position in which he bends the 23rd overlaps, displaceable on the rail 27, the Clamping device 42 can be released so that the Spring element 49 between the compressed air hose 47 and the Profile part 48 is displaceable.

Claims (9)

1. A bending press (20) for edging workpieces (22) along a bending line (23), having a work area (17) located in front of the bending line (23), a detent area (24) located behind the bending line (23), having a drive mechanism (21) for the lifting movement of a bending tool (9), having a lift actuating device (7) activating the drive mechanism (21) and a switch locking mechanism for the lift actuating device (7) , having a detent device (26) arranged in the detent area (24), which has a rail (27) which can be displaced perpendicularly in respect to the bending line (23) and positioned by means of a controllable drive mechanism, and on which at least two detent fingers (28, 29), which can be manually displaced along the rail (27), can be positioned and fixed in place by means of a clamping mechanism (42), are arranged, characterized in that a blocking device is provided for releasing the clamping mechanism (42), and that the detent device (26) can be displaced into a position, in which the detent fingers (28, 29) project across the bending line (23) into the work area (17) of the bending press, and that in this position the switch locking mechanism becomes operative, and the blocking device for releasing the clamping mechanism (42) becomes inoperative.
2. The bending press in accordance with claim 1, characterized in that the clamping mechanism (42) is constituted by a clamping element which, when actuated, clamps the detent fingers (28, 29) to the rail (27).
3. The bending press in accordance with claim 2, characterized in that the clamping element has at least one element or a corresponding section which, when actuated, presses against the rail (27) and the detent fingers (28, 29).
4. The bending press in accordance with claim 2 or 3, characterized in that the clamping element is constituted by a compressed air cylinder or a magnet.
5. The bending press in accordance with one of claims 2 to 4, characterized in that the position and/or shape of the clamping element can be changed by its being charged with a fluid.
6. The bending press in accordance with one of claims 2, 3 or 5, characterized in that the clamping element consists of a hose which can be filled with a fluid, for example a compressed air hose (47), whose cross-sectional shape and/or position can be changed by means of interior pressure.
7. The bending press in accordance with one of the preceding claims, characterized in that the switch locking device has a switch which interrupts the energy supply to the lift actuating device (7).
8. The bending press in accordance with one of the preceding claims, characterized in that the blocking device for releasing the clamping mechanism (42) has a switch which interrupts the energy supply for releasing the clamping mechanism (42).
9. The bending press in accordance with one of the preceding claims, characterized in that a release device for releasing the clamping mechanism (42) is provided, and that the blocking mechanism deactivates the release device.

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