reza_1364
مدیر بازنشسته
Air Bending
In air bending, there is no need to change any equipment or dies to obtain different bending angles because the bend angles are determinated by punch stroke. The forces required to form the parts are relatively small, but accurate control of the punch stroke is necessary to obtain the desired bend angle.
V-die Bending
In V-bending, the clearance between punch and die is constant (equal to the thickness of sheet blank). It is used widely. The thickness of the sheet ranges from approximately 0.5 mm to 25 mm.
U-die Bending
U-die bending is performed when two parallel bending axes are produced in the same operation. A backing pad is used to force the sheet contacting with the punch bottom. It requires about 30% of the bending force for the pad to press the sheet contacting the punch.
Wiping
Wiping die bending is also known as flanging. One edge of the sheet is bent to 90 while the other end is restrained by the material itself and by the force of blankholder/pad . The flange length can be easily changed and the bend angle can be controlled by the stroke position of the punch.
Coining
In coining, compressive stress is applied to bending region to increase the amount of plastic deformation. This reduces the amount of springback.
Bottoming
In bottom bending, springback is reduced by setting the final position of the punch such that the clearance between the punch and die surface is less than the blank thickness. As a result, the material yields slightly and reduce the springback. Bottom bending requires considerably more force (about 50%~60% more) than air bending.
Double Die Bending
Double die bending can be seen as two wiping operations acting on the workpiece one after another. Double bending can enhance strain hardening to reduce springback.
Rotary Bending
Rotary bending is a bending process using a rocker instead of the punch. The advantages of rotary bending are:
· a) needs no blankholder
· b) compensates for springback by overbending
· c) requires less force
· d) more than 90 degree bending angle is available
In air bending, there is no need to change any equipment or dies to obtain different bending angles because the bend angles are determinated by punch stroke. The forces required to form the parts are relatively small, but accurate control of the punch stroke is necessary to obtain the desired bend angle.
V-die Bending
In V-bending, the clearance between punch and die is constant (equal to the thickness of sheet blank). It is used widely. The thickness of the sheet ranges from approximately 0.5 mm to 25 mm.
U-die Bending
U-die bending is performed when two parallel bending axes are produced in the same operation. A backing pad is used to force the sheet contacting with the punch bottom. It requires about 30% of the bending force for the pad to press the sheet contacting the punch.
Wiping
Wiping die bending is also known as flanging. One edge of the sheet is bent to 90 while the other end is restrained by the material itself and by the force of blankholder/pad . The flange length can be easily changed and the bend angle can be controlled by the stroke position of the punch.
Coining
In coining, compressive stress is applied to bending region to increase the amount of plastic deformation. This reduces the amount of springback.
Bottoming
In bottom bending, springback is reduced by setting the final position of the punch such that the clearance between the punch and die surface is less than the blank thickness. As a result, the material yields slightly and reduce the springback. Bottom bending requires considerably more force (about 50%~60% more) than air bending.
Double Die Bending
Double die bending can be seen as two wiping operations acting on the workpiece one after another. Double bending can enhance strain hardening to reduce springback.
Rotary Bending
Rotary bending is a bending process using a rocker instead of the punch. The advantages of rotary bending are:
· a) needs no blankholder
· b) compensates for springback by overbending
· c) requires less force
· d) more than 90 degree bending angle is available
