| 摘要 |
<p>A vacuum generating unit is provided to connect a vacuum port with the atmosphere only at positive pressure in which a negative pressure state is released or cancelled so as to maintain negative pressure for material maintenance. A vacuum generating unit includes a main body(12) in which a supply port(24) supplying a pressure fluid, a vacuum port connected to a chucking tool and an exhaust port(64) discharging the pressure fluid supplied from the supply port are arranged, a vacuum generating unit(14) generating negative pressure according to the operation of the pressure fluid supplied from the supply port, a supply valve(69a) switching the pressure of the pressure fluid supplied to the vacuum port to a negative pressure state and a positive pressure state, a switching valve(22) having a vacuum cutoff value(69b), and an atmosphere introducing valve(40) for changing the connecting state of the vacuum port and the atmosphere.</p> |
