Metal deforming – With indication of condition or position of work – product,... – Work drawn or extruded through die
Patent
1997-02-07
1998-12-01
Jones, David
Metal deforming
With indication of condition or position of work, product,...
Work drawn or extruded through die
72 3111, 723893, 72702, B21D 502
Patent
active
058423664
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention concerns a method of bending workpieces, especially sheet metal, in which there is a workpiece acted on by a upper die and/or a lower die that works with it, and at least one side of the workpiece is bent at an angle in relation to at least one other side of the workpiece, and the workpiece is then released from the upper die and/or the lower die, and, when the workpiece is released from the upper die and/or the lower die, the actual size of the bending angle is determined and after at least approximately complete release of the workpiece from the upper die and/or the lower die, the actual size of the bending angle then existing is compared to the desired size.
The invention also concerns a tooling machine for bending workpieces, especially sheet metal, by a method like the one described, with a lower die and a upper die that works with it and is able to move in the bending direction relative to it with a drive regulated by controls, as well as at least two scanning elements, which can be moved in relation to one another in the bending direction relative to the upper die and/or lower die and are supported in the measurement position on at least one of two sides of the bent workpiece that form a bending angle on the bent workpiece, wherein the relative position of the scanning elements is a measure of the actual size of the bending angle, and the scanning elements are connected to a device for determining the actual size of the bending angle.
As is known, when workpieces are bent, especially sheet metal, an unwanted elastic deformation of the workpiece occurs, in addition to the plastic deformation sought. Due to the elastic deformation, after the workpiece in question is released from the upper die, the result is a springing of the workpiece angle made during the bending process and with it an increase in the bending angle formed by the sides of the workpiece angle. This makes it harder to bend workpieces with a definite bending angle whose actual size is predetermined.
In one common conventional method, the phenomenon described is taken into account by the fact that, after the first work cycle, when the workpiece is released, the actual size of the bending angle achieved is measured and compared to its desired size. If it turns out from this comparison that the actual angle is larger than the desired angle, a corrective work cycle is started, after the end of which when the workpiece is released, another actual/desired size comparison is made of the bending angle. The bent workpiece is rebent and corrected until the desired tooling result is achieved.
To use the method described, a bending machine or press brake with the conventional features specified at the beginning is used. Here, the distance between the scanning elements in the bending direction and in the direction of movement is used as the basis for trigonometric calculation of the bending angle.
Other known tooling machines for using the conventional method employ an inductive or a pneumatic measurement device. In both cases, when the workpiece is released from the upper die after a bending process for two points on each side of the workpiece, its distance from the opposite side and a side on the lower die bounded in cross section by a V-shaped groove is determined. The course of the sides of the groove of the lower die gives the desired size of the bending angle to be made. By determining the distance between the measuring points on the sides of the workpieces from the assigned groove side, it is determined whether the workpiece sides run parallel to the groove sides and thus form the angle that is desired, or whether the sides of the workpiece angle are in turn pointing at an angle to the sides of the groove and as a result deviate from their desired course. The actual size of the bending angle made in the preceding bending cycle is determined from the distance values measured.
With the state of the art described above, there are neither method-related nor device-related means that would make it possib
REFERENCES:
patent: 4489586 (1984-12-01), Hess
patent: 4864509 (1989-09-01), Somerville et al.
patent: 5007264 (1991-04-01), Haack
patent: 5062283 (1991-11-01), Miyagawa et al.
patent: 5483750 (1996-01-01), Ooenoki et al.
patent: 5603236 (1997-02-01), Hongo
Horn Armin
Klingel Hans
Jones David
Trumpf GmbH & Company
LandOfFree
Method and a tooling machine for bending workpieces does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and a tooling machine for bending workpieces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and a tooling machine for bending workpieces will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2388885