Analysis of the relationship between bending formation and grooving process
The traditional bending process is to use the two edges at the opening of the lower die and the top edge of the upper die to bend the metal sheet under the pressure of the upper and lower molds of the NC press brake. The sheet metal undergoes elastic deformation to plastic deformation. The bending angle is determined by the depth of the upper mold entering the lower mold. In today’s society, people have higher and higher requirements for the shape of the workpiece. Some workpieces with complex shapes can no longer be bent using traditional free bending, bending machine bending or even three-point bending technology, and traditional bending methods cannot control the bending. The radius of the rounded corners makes it difficult to achieve the process requirements for seamless bending. Therefore, a new type of bending process-grooving bending process came into being.
It can be seen from the bending process that the size of the edge arc radius of the workpiece after bending is in direct proportion to the thickness of the sheet. The thicker the sheet, the larger the radius of the arc formed by bending. After V-grooving the metal sheet, the remaining thickness of the sheet becomes half of the original thickness, or even smaller, so that the edge arc radius after the workpiece is bent can be greatly reduced. In addition, since the remaining thickness of the bend is thinner after grooving, the deformation force during bending will be reduced accordingly, and will not spread to the unbent area. Therefore, there are no creases on the surface of the workpiece after bending, and due to bending The thickness of the board is thinner, and the pressure required during bending is reduced to avoid the risk of indentation on the decorative surface. In this way, the metal decoration of high-end places such as hotels, banks, commercial centers, airports, etc., has a small arc radius of the workpiece edge, no creases on the surface, and no indentation on the decorative surface.
In the bending process, the required bending force of the sheet metal is proportional to its thickness. The greater the thickness of the sheet metal, the greater the bending force required, and the required equipment tonnage increases accordingly. After V-shaped grooving is performed on the bending part of the sheet metal before bending, the remaining thickness of the sheet at that place is greatly reduced, so that the bending force required when the sheet is bent will also be correspondingly reduced, so that the thick plate can be in a smaller tonnage Bending on the bending machine. This not only reduces the investment in equipment, but also saves energy and space.
How to avoid the deviation of bending angle and size
For the bending process, the quality of bending mainly depends on the two important parameters of bending angle and size. When bending, in order to ensure the forming size and angle of the bending, the following issues need to be paid attention to.
⑴ The upper and lower molds are not aligned with each other, which will cause errors in the bending dimensions. The upper and lower mold tools need to be aligned before bending.
⑵ After the left and right positions of the rear stopper are moved, the relative position of the sheet metal and the lower die may change, which will affect the bending size. The position distance of the rear stopper must be re-measured before bending.
(3) Insufficient parallelism between the workpiece and the lower die will cause bending springback and affect the bending angle. The parallelism must be measured and adjusted before bending.
⑷ When the angle of the first bending is insufficient, the second bending will also be affected. The accumulation of bending errors will increase the forming size and angle errors of the workpiece. Therefore, it is particularly important to ensure the accuracy of single-sided bending.
⑸When bending, the size of the lower die V port is inversely proportional to the bending pressure. When processing metal plates of different thicknesses, you need to select the appropriate lower die V-groove according to the regulations. Generally, 6-8 times the plate thickness is the most appropriate .
⑹ When the workpiece is bent on the bending machine after planing the V-shaped groove, ensure that the edge of the upper die, the bottom edge of the V-shaped groove of the workpiece and the bottom edge of the V-shaped groove of the lower die are on the same vertical surface.
⑺ When bending the workpiece after grooving, in order to prevent knife clamping, the upper die angle is best controlled at about 84°.
grooving process, as a new type of bending process, is the result of market choice. With the continuous development of process technology, enterprises have higher and higher requirements for process personnel. As craftsmen, only by mastering various processing techniques can we produce better products; only by constantly exploring and pursuing new techniques can we produce better products.