How to Choose Dies for CNC Bending Machines

We can analyze the selection of dies for CNC bending machines from two aspects: the upper die and the lower die.

1. Let's first discuss the selection of the upper die for a CNC bending machine.

The selection of the upper die should be based on the magnitude of the bending force. It's important to note that the die's load must not exceed its limit. If the user selects a special die, special attention should be paid to the fact that the load of these dies differs from that of normal dies. Correct selection of the upper die is crucial to prevent the bending force from exceeding the upper die's load limit, which could cause the die to break and injure people.

The shape of the upper die of a CNC bending machine has a significant impact on whether the workpiece can be bent and formed. When programming and selecting the die, the die's shape must be considered to ensure it doesn't interfere with the workpiece during the forming process.

When the die is entered into the CNC system's die library, the die's external dimensions must be programmed accurately. The CNC system can then accurately calculate whether the die interferes with the workpiece during the automatic bending process.

2. Selection of Lower Die for CNC Bending Machine

The width of the V-shaped lower die V must be determined according to the material thickness t using the following formula:

t < 3mm V = (6～8)×t

t ≥ 3mm V = (8～12)×t

Similarly, the width of the lower die V can be reasonably and scientifically determined based on the change in the minimum bending width b and the fillet radius r of the bent part.

During the bending process of the CNC bending machine, the bending force generated will accumulate on the worktable and also act on the die. Therefore, it is important to ensure that the load on the die does not exceed its limit.