A cyclone dust collecting device of a vacuum cleaner, which is mounted on a telescopic extension pipe. To help avoid overheating of the tip, the system determines an approximate temperature of the eye using an irrigation flow rate and reduces the power to the handpiece automatically if an overheating situation is predicted. The model computation module 140 computes a physical behavior of the adjustable valve mechanism 120 according to a physical model, in response to a control signal input from the VVT controller 110.