BERGLUND KENNETH (SE)
| US4366698A | 1983-01-04 | |||
| US5249452A | 1993-10-05 | |||
| CH680772A5 | 1992-11-13 |
| 1. | Arrangement for a die tool for a press brake, especially a die tool having pairs of die jaws (2) adjustable in a sideways direction symmetrically around a centre plane, whereby the die jaws are arranged on parallel mounting surfaces (1) that by means of gripping oblique surfaces at mutually displaceable devices are able to continuously increase and decrease the distance between the parallel mounting surfaces and thereby the die jaws by a defined interval characterised in that the die jaws (2) at each mounting surface (1) are arranged to be displaceable in steps between at least two defined attachment positions separated in a sideways direction and arranged symmetrically around the centre plane. |
| 2. | Arrangement according to claim 1 characterised in that the die has sections of die jaws (2) in pairs along the tool. |
| 3. | Arrangement according to any of the previous claims characterised in t h a t the die jaws (2) can be attached in a removable manner to the mounting surface (1) by means of a screwed joint, preferably in combination with a keyed joint or guide pin or similar positioning device. |
| 4. | Arrangement according to claim 3 characterised in that threaded holes (10) for accommodating attachment screws (11) are arranged in the mounting surface (1), that the threaded holes (10) are distributed evenly along a line on the mounting surface (1) parallel with the centre plane. |
| 5. | Arrangement according to any of claims 24 characterised in that at least one of the sections has a means of measuring angles (12). |
An arrangement for die tools for press brakes having die jaws arranged in pairs and continuously adjustable in a sideways direction is known through SE 503 594. A series of slots arranged as pairs pointing in opposite directions on either side of the centre plane of the tool is arranged on parallel sliding surfaces on a sliding plate. On the facing sliding surface associated with the respective die jaws, mirror-imaged similarly located slots with a length greater than the previous slots are arranged, and in the shorter slots, wedges or similar guiding elements suitably adapted to the length of the slots are arranged so that each projects into one of the longer slots with an upwardly projecting section.
Through a displacement of the sliding plate in the longitudinal direction, a sideways movement is achieved that either separates or brings together the counter die depending on the direction of the longitudinal movement. In addition, a clamping device for fixing the die jaws in a working position is shown.
This arrangement has a continuously adjustable die width over a working area of approximately 50 mm. To obtain a larger working area with the same technology would mean that the size of the arrangement would be so bulky that the working area of the press brake would be encroached on as the sheet billet that is to be bent would quite simply be hindered by the arrangement. In addition, changing the tools in press brakes when production occurs in short series or when several different stepwise bendings of different geometries and possibly of different materials takes place is known to be problematic.
The aim of the present invention is to reduce or overcome the problems that remain as stated above and achieve a flexible system for a press brake die tool that allows efficient production even when bending short series or when bending in several stages or at several work stations.
This aim is achieved with an arrangement as first named above and that has the characteristics specified in claim 1. The subsequent claims show characteristics of embodiments of the invention.
A preferred embodiment of the invention will be described in more detail below with reference to the attached drawings where the same or similar items have been designated with the same reference number.
Fig. 1 shows schematically a perspective view of a die tool according to one embodiment of the present invention mounted on a pressing table head.
Fig. 2 shows schematically a side view of the embodiment according to Fig. 1.
With reference to Fig. 1, die jaws 2 are shown arranged on a mounting surface 1.
As in this embodiment, the die, which is formed by pairs of the die jaws 2, comprises sections, the sections can also have varying geometries for different types of bending. The variations can be, for example, in length, height, die radius, etc. In this manner, the die tool can satisfy the equipment requirements for several basic working stations.
As is also evident from Fig. 1, one or more die sections can advantageously be equipped with an arrangement for measuring angles 3, for, for example, bending individual billets, billets of expensive material or of lower quality material. Here, lower quality means material with variations in its properties, which in turn means that the parameters set for bending do not result in the same final angle for all billets. Such an angle measuring station can accordingly be moved in the same simple way as the other die sections, which will be described in more detail below.
With reference to Fig. 2, the current embodiment has a fundamental technique for the sideways displacement of the die jaws, which is described in detail in SE 503 594. The technique means taking advantage the of the die jaws 2 arranged in pairs and continuously adjustable in a sideways direction. A series of slots 6 arranged as pairs pointing in opposite directions on either side of the centre plane of the tool are arranged on parallel sliding surfaces 4 on a sliding plate 5. On the facing sliding surface 7 on two mounting strips 8, one each for the respective die jaw on that side, mirror-imaged similarly located slots with a length greater than the previous slots are arranged, and in the shorter slots, wedges or similar guiding elements suitably adapted to the length of the slots are arranged so that each projects into one of the longer slots with an upwardly projecting section.
Through a displacement of the sliding plate 8 in the longitudinal direction, a sideways movement is achieved that either separates or brings together the die jaws 2 depending on in which longitudinal direction the sliding plate 8 is displaced. In addition, a clamping device 9 for fixing the mounting strips and thus the die jaws in a working position is arranged.
The die jaws 2 are firmly attached by screws in sections on the upper side of the mechanism, designated the mounting surfaces 1. At least two rows of permanent attachment positions for the die jaws 2 separated from one another in a sideways direction are arranged on the mounting surfaces 1. The attachment elements can, as in the example shown, be made up of screw joints and guiding wedges that interact between a die jaw 2 and a mounting surface 1. In
this way, individual pairs of die jaws can be positioned to work in an outer or inner working area. Preferably, the outer and inner attachment positions are located in relation to one another so that their working areas only overlap to a limited extent. If the die tool is then equipped with a pair of die jaws 2 in the inner position in a first section and an equivalent pair of die jaws 2'in the outer position in a second section, the combination of these two section achieves a continuous working area that is double the size of the original.
The combination of in part the continuously variable die width within a relatively large area, in part the at least two different fixed basic attachment positions between which the pairs of die jaws can be moved in a sideways direction, and in part the sectioning of the die jaws achieves, in relation to known technology, a significant improvement in relation to flexibility and efficiency in the use of a press brake.
It should of course be understood that the upper die tool, even if not explicitly described here, can be executed in sections that agree with the die tool and that the upper die tool can thus be adapted to the die section-by-section.