Press brake bending is straightforward stuff
Arrow-shaped punch presses a sheet metal blank into a v-shaped expire, and thereby forming an angled bend. Or perhaps, if we are getting adventurous, we can envision something like a gooseneck punch creating yield flanges, but this is stretching it as far as it goes, right?
No, not very. Press brake tooling has come a long way in the last few decades, and may do far more than it used to, and likely far more than you might imagine. Some of the more interesting techniques comprise:
- Rocker dies
- 3 way bending and
- Elastomeric bending
A wiping operation is made up of more than one movement, unlike simpler shaping procedures
A special die set is used, where the underside die has movable elements. As the punch moves down and implements the initial part of the flex, the bottom element gets the sterile and is pressed down on its own springs. This motion activates an element on the back of the die, which moves in and implements the second area of the bend. A good illustration of the use of this technique is the making of a radiused yield flange: The sterile is pushed down on the very first, spring-loaded component, and the consequent downward motion bends the sterile to a right angle using a radius at the bending point. The second component then comes into play and finishes the job by bending the edge of the sterile over, creating a return flange in the procedure.
Rocker dies are basically simple dies – with a twist: The best perish has a built in 1-axis joint, allowing it to enter a bottom expire with a partly obscured opening. This makes it feasible to form a channel in one pass, even if the flange is extremely long – something that (depending on the form of the part) may not be doable in a traditional channel die set. If that’s the circumstance, rocker dies supply the advantage of reduced setup time and fewer operations so as to form the part.
The term 3 point bending is used about a special sort of die set, where the base die has an element that may be adjusted in height with a servo motor. The best die is buffered from the ram using a unique hydraulic cushion to compensate for little variations in the depth of the blank. Together, both dies make it feasible to achieve extreme precision in the angles bent down to 0.25 levels. This sort of tooling is expensive however. Click here
Elastomer bending is especially interesting
Here, the bottom die is not steel, but a level piece of synthetic material which functions to wrap the sterile around the punch, as it comes down. The consequent bend radius will probably be quite near the punch radius, as there is little springback. Additionally, the elastomeric pad does not mar or scratch the sterile.