#114 Terminology and Surroundings (8) Floating Dies
Fig. 1 shows a die for a product having an upward bend and a downward bend. In this structure, movable punch and die are used which are supported by springs. Such dies and punches are called floating dies and floating punches.
Let us explain why such cumbersome structure is necessary. Consider the downward bend in the structure of Fig. 1. The floating punch becomes a pad. The floating punch (= pad) presses the material, and after that, the spring behind the pad flexes and the downward bend punch starts the downward bending operation. The bending is not possible unless the floating punch (pad) and the downward bending punch are not in this relationship.
When we consider the upward bending, the floating punch is the upward bending punch. The floating die becomes the pad for upward bending. The floating punch presses the material, and starts the upward bending by pushing down the upward bending pad (floating die).
It can be understood that the floating punch and the floating die are compound components having the function of pads. Since a pad is a component that moves while pressing, it is supported by a spring and is in the floating state. Since this component is simultaneously used as a punch or a die, the term floating punch or floating die have come to be used. This is a die structure with such floating components which is used frequently for complex forming or progressive forming.
The relationship between the forces of the spring A and the spring B in Fig. 1 is discussed below.
- When A=B and both are stronger than the bending force, the upward bending and the downward bending progress simultaneously. After the floating punches press the material, since the springs A and B flex equally. However, since it is very difficult to prepare this state, normally this kind of design is not done.
- In the state in which A>B, if the spring force of the spring A is more than the bending force + the spring force of B, when the floating punch presses the material, the spring B below the floating die starts to flex and the upward bending starts. The upward bending is completed when the floating die has hit the bottom. The spring A starts flexing from this state and the downward bending starts, and the upward bending and downward bending both are completed in the state shown in Fig. 2.
- In the state in which A<B, if the spring force of the spring B is more than the bending force + the spring force of A, the downward bending starts first and when the floating punch hits the bottom, the spring B starts flexing and the upward bending starts. The bending progresses with relationships opposite to that of (2) above and the upward and downward bending both are completed in the state shown in Fig. 2.


- #167 Problems in Punching and their Countermeasures (6) Scrap Processing in Punching
- #166 Problems in Punching and their Countermeasures (5) Trimming of Drawn and Shaped Parts
- #165 Problems in Punching and their Countermeasures (4) Scrap Clogging in Punching
- #164 Problems in Punching and their Countermeasures (3) Bending and Twisting of Narrow Punched Parts
- #163 Problems in Punching and their Countermeasures (2) Bending due to Punching

