Why does the punch stop at the top dead center?

Let's talk about the off-brake type first, and brake by the friction plate (clutch plate) in the clutch. At different speeds, the friction sliding angle is different. The greater the speed, the greater the friction slip angle, which can be approximated as a straight line in the low speed range.

To stop the top dead center, it is necessary to determine the current speed and the sliding angle to stop, so that the punch can stop at the top dead center position.