The key to sheet metal bending design is the martial arts secret script of sheet metal design circle!
Source: | Author:佚名 | Published time: 2021-06-29 | 73 Views | Share:

The key to sheet metal bending design is the martial arts secret script of sheet metal design circle!

Sheet metal bending design is a stamping process, which forces plastic deformation of material by pressure, thus forming a shape with angle and curvature. The common bending includes V-bending, z-bending and back pressure bending. 1.1 bending height. The bending height of sheet metal parts shall be at least twice the thickness of sheet metal parts plus the design radius of sheet metal bending, i.e. H > 2T + R. If the bending height of the sheet metal is too low, it is easy to deform and twist when the plate is bent, and it is not easy to obtain the ideal shape and size, As shown in the figure, in the original design, the bending quality is low due to the small bending height on the left, which makes it easy to deform during bending. In the improved design, the left bending height can be increased or the bending height can be removed. The smaller part makes the metal plate not deform when bending, and the bending quality is high. 1.2 to ensure bending strength, bending radius shall be larger than the small bending radius of material, as shown in the following figure. The original and improved sheet metal bending radius design is shown in the figure. The larger the bending radius of sheet metal parts, the greater the radius, the greater the bending rebound, the more difficult the control of bending angle and bending height. Therefore, the bending radius of sheet metal should be reasonable. The die manufacturer tends to set the bending radius to 0, so the radius after bending is not easy to reverse, and the design height and bending angle of sheet metal bending are easier to control. However, if the bending radius is zero, it is easy to cause the external crack or even fracture of the metal plate. At the same time, the bending strength of the metal plate is relatively low, especially for the hard sheet metal materials. After a period of production, the die right angle on the mold will gradually become smooth, and the bending size will become difficult to control. Another method used by sheet metal die manufacturers to reduce bending forces and ensure bending dimensions is to pre add crimping processes before bending. Of course, such designs will cause defects such as relatively low bending strength and the vulnerability of metal plates to fracture. The pressing process is a stamping process, which forces the material to be extruded locally and extrudes a groove on the metal plate to facilitate bending and ensure the bending accuracy. Process 1.3 bending direction when the metal plate is bent as far as possible, it shall be perpendicular to the direction of the metal material fiber. When the sheet metal is bent parallel to the direction of the metal fiber, cracks are easily produced at the bending position of the sheet metal, and its strength is low and it is easy to break.

1.4 avoid failure of sheet metal bending design due to the bending root unable to press the material. When bending a sheet metal, it is usually because other features are too close to the root of the sheet metal bending, which makes it impossible to squeeze the material and cause serious deformation of bending or bending. In general, it shall be ensured that the minimum thickness of the sheet metal plus the bending radius is above the root of the bend. When the sheet metal is bent, there is no other function to prevent extrusion of the material. The original design is displayed on the top of the original design. The bending root too close to the sheet metal can not squeeze the sheet metal during the bending process, and the bending fails; As shown in the lower part of the figure, in the original design, the sheet metal was pulled too close to the bending root to bend. Remove the pull out teeth from the root of the sheet metal. If the pull out and bending positions cannot be moved due to design requirements, a process cut can be added to the root of the bend corresponding to the pull out to ensure smooth bending. 1.5 ensure the bending clearance to avoid bending interference. Because of the bending tolerance of sheet metal parts, the bending clearance must be ensured in the direction of bending movement of sheet metal parts to avoid bending failure due to interference during bending. The bending sequence of this part is to bend the upper side first and then the right side. In the original design, there is no gap between the two bends. When the upper side is bent, the right side bends again. The presence of gold bending tolerances is likely to cause interference between the right and upper sides during bending. In the improved design, a minimum of 0.2mm clearance is left between the right and the upper side, which can effectively avoid interference. 1.6 when the bending strength is guaranteed to bend the metal plate, the bending strength must be ensured. The long and narrow bending strength is low, while the short and wide bending strength is high. Therefore, as shown in the figure, the bending of the sheet metal should be attached to the longer side as much as possible, with the same bending function. In the original design, the bending strength was lower because the bending was attached to the shorter side. The improved design is attached to the longer side and has high bending strength.

1.7 reduce bending process. The more bending process of sheet metal parts, the higher the cost of the die, the lower the bending accuracy. Therefore, sheet metal design should minimize the bending process. As shown in the figure, the original design of the sheet metal requires two bending processes. In the improved design, sheet metal can complete two bending at the same time by only one bending process. 1.8 avoid complex bending. The more complex the design process of sheet metal bending, the higher the cost of die, the lower the bending accuracy, the more complex the bending. It may cause waste of parts and materials. Therefore, when sheet metal has complex bends, you can consider dividing the complex bending into two parts and then assembling it by studs, self rivets or spot welding. 1.9 multiple bending holes are difficult to align with sheet metal. The bending tolerance is relatively large, especially when bending many times, the accumulation of tolerance makes it difficult to align the holes and holes. The more bending time of sheet metal parts, the greater the bending tolerance, and the difficulty of bending multiple sheet metal parts to ensure the dimensional accuracy. This is why it is difficult to align screw holes, stud holes and self rivet holes on bent metal plates. Solution: design the bending hole as a large hole or long round hole, allowing larger bending tolerance to increase two internal positioning holes. The mold increases internal positioning, reducing the tolerance of sheet metal during bending, so as to ensure that the holes on the two elbows are aligned, and then the holes are punched after bending. The accuracy of the hole size can be guaranteed, but it will increase the complexity of the stamping die and increase the cost of the die. Generally not recommended