1. Bending Dies
Typical dies consist of a middle plate, upper die, lower die, guide rails, lower die holder, etc. These dies are versatile and can handle most machining tasks.
2. Selection of Bending Dies
Different parts require the use of different dies. It is essential to understand the machining parameters of the machine tool and the dies to select compatible dies.
Machine tool parameters include: stroke, machining capacity, open height, type of middle plate, etc. Die parameters include: type of upper die handle (matching the middle plate), pressure tonnage (maximum bending pressure), etc.
A. Selection of Machine Tool Parameters
1. Selection of Die Height
Stroke (mm) = Open height - Middle plate height - Upper die height - Lower die holder height - (Lower die height - 0.5V + t) where t is the sheet metal thickness (mm).
When selecting the lower die holder, it is important to note that there are various heights of lower die holders, each suitable for different machining requirements.
Different combinations of dies can provide different die combination heights for machining different parts.
B. Selection of Die Parameters
1. Type of Upper Die Handle
There are three forms of upper die handles to match different middle plates.
2. Shape of Upper Die
Common standard shapes of upper dies include:
3. Radius and Tip Angle of Upper Die
Common radii for upper dies are: (1) 0.2R, (2) 0.6R, (3) 0.8R, (4) 1.5R, (5) 3.0R.
Choosing the appropriate radius: Generally, R0.6 is used for thicknesses below 3mm.
Standard tip angles for upper dies include: 90 degrees, 88 degrees, 86 degrees, 60 degrees, 45 degrees, 30 degrees, etc.
The die angle should be smaller than the bending angle. For example, if we are bending a workpiece to 90 degrees, a die with an angle of 88 degrees is used.
4. Type of Lower Die
Common lower dies include single V and double V, with further distinctions between segmented and integral types. Different die types are suitable for different machining needs.
Generally, single V dies have a wider range of applications than double V dies, and segmented dies are more versatile than integral ones. Our company typically uses double V and triple V for lower dies.
5. Width of Lower Die V, V-groove Angle
The selection of the lower die V groove is related to the material thickness (T):
The V groove angle of the lower die should match that of the upper die.
