CS244326B1 - Device for straightening large-area moldings by stretching - Google Patents

Abstract

The invention relates to a device for straightening large-area stampings by tensioning, comprising two pairs of clamping bodies for their attachment to the press slide and to the press table, which are provided with clamping jaws, as well as a support table for supporting the stamping on the press table. The essence of the invention is that the active part of the upper fixed jaws (3) and the lower fixed jaws (4) is formed in the shape of an inclined plane, provided with a groove and where in the given fixed jaws the upper and lower movable jaws are slidably mounted in the grooves. The contact surfaces of these movable jaws are beveled at the same angle as the inclined planes of the fixed jaws, while the movable jaws are also provided on one side with a recess for the compression spring (7j, which is limited on the other side by a support plate (9). The active part of the movable jaws is provided with protrusions or has a roughened surface.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for straightening large-area moldings by tensioning, particularly piece and low-volume production, wherein the apparatus is adapted to be clamped to mechanical or hydraulic presses when the width of the slide and the press shaft is sufficient. Nowadays, in engineering technology, in piece and small series production, we are able to achieve equalization by hammering, flame heating, resistive heating, die-casting with shrink-on and non-shrinking jaws, and on rollers.

A clamping head of a sheet straightening device is known, provided with a centering mechanism, particularly suitable for large-scale production. Furthermore, a hydraulic sheet metal alignment system is known by the use of firmly clamped jaws.

In addition, a device is provided for stretching a blank clamped on two opposed sides in rigidly tightening devices between a recessed lower part of the tool on a sheet metal part which is curved in both radial and transverse directions, whereby the length of the flat part of the blank, in Depending on the shape of the prefabricated element and the ability of the sheet metal used to stretch in the reshaping tool with more bending stress. The clip can also be clamped on one side or not clamped.

Balancing or heating is little productive and requires skilled workforce. Also, the flatness of the sheet made by such a technology is slightly inadequate with respect to the requirements of the final part. Straightening or extensible straightening devices, roller straighteners suited for mass production from an economical point of view.

The above-mentioned drawbacks are solved by a device for flattening large-area moldings by tensioning, comprising two pairs of clamping bodies for clamping them on a press slide and on a table-top which is provided with clamping jaws as well as a support table for supporting the mold on the press table, the essence of which is the female part of the upper rigid jaws, as well as the rigid jaws formed in the face of the inclined plane provided with the groove and the upper movable jaws in the fixed jaws and the lower movable jaws; it is chamfered under the same angle as the inclined planes of the rigid beds, wherein the upper movable jaws, as well as the lower movable jaws, are provided on one side with a recess for the compression spring and on the other hand a given pressure spring bounded by the support plate. The active part of the movable jaws is provided with projections or has a roughened surface.

The condition for straightening is that the equalized large-area molding is stretched by stretching up to the yield point Re so that it has a permanent deformation ε> 0.4%. In doing so, it is appreciated that the deformed sheet has one side with shortened fibers and a sufficient deformation under the yield point Re to cause plastic deformation, whereby the shortened sheet metal is extended and the sheet is leveled. An advantage of the tensioning device according to the invention is that it can be clamped to mechanical or hydraulic presses when the width of the slide and the press shaft is sufficient. Particularly advantageous is the use of a folding device where the length of the straightening can be up to several meters. The movable jaws are provided with projections on the contact surfaces. The purpose of these protrusions is to make friction between the sheet and the moving parts lighter. At the same time, the movable jaws align the clamped plate. The device can be moved by the slider and the press table, whereby its length can be freely adjusted to the required size. According to the invention, the solution of the invention is better aligned with the large-area molding, the work hygiene is improved and the use of mechanical and hydraulic press brakes is extended. The device is particularly suitable for piece and small series production.

In the accompanying drawing, a schematic illustration of a device according to the invention is shown.

The device, as shown, consists of two pieces of clamping bodies 1 of the upper two pieces of clamping bodies 2 of the lower, which are attached to the slide or the slide. press brake. Two pieces of upper fixed jaws 3 and two lower jaws 4, which are inclined by inclined planes, are attached to the upper body 1 and lower body 2. Following the inclined planes of the fixed jaws 3 and the fixed jaws 4, the upper movable jaws 5 and the lower movable jaws 6 are movably formed, on which the springs 7 press on one side abutting the recesses and the other anchored in the support plate 8. On the table The press brace is supported by a device support consisting of a gallery 9 of a housing 10 in which a spring 11 is mounted on the body 12.

The device according to the invention operates in such a way that a large-area molding is placed on the lower movable jaw 6 and supported in the device by a support device arranged in the center of the press brake press 14. The movement of the press slide 13 on which the upper part of the tensioning device is clamped the lower movable jaws 5 and the lower movable jaws 6 on the contact surfaces together with the springs 7k of the flattened blank 13 and clamp it. By moving the slide of the press 13a, a pressure is exerted which shifts

Claims (1)

2, 4, 3, 3, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 11, 12, 12, 11, 12, 12, 12, 11, 12, 11, 12, 11, 12, 11, 12, 12, 12; At the same time, the large-area molding 13 is also the same on the contact surfaces of the movable upper jaws 5 and the movable lower jaws 6, which are provided on the contact surfaces provided with projections or roughened on the active surfaces. OBJECT A device for leveling large areas by stretching, comprising two pairs of clamping bodies for gripping them on a press slide and on a press table which are provided with clamping jaws as well as a support film for supporting the blank on a press table indicating in that the active upper part of the upper jaws (3) as well as the lower fixed jaws (4) is formed in the form of a tilted plane provided with a groove and where in the fixed jaws the upper movable movable jaws are slidable in the grooves; the jaws (5) of the invention as well as the lower movable jaws (6j, whose bearing surfaces are bevelled under the same angle as the inclined planes of the fixed jaws (3, 4), wherein the upper movable jaws (5) as well as the lower movable jaws (6) coincide with one a recessed side with a compression spring (7) which is laterally delimited by the support plate (8) and wherein the active part of the movable jaws (5, 6) is provided protrusions or a rough surface 1 sheet of drawings