| 摘要 |
PURPOSE:To expand the pressure control range and to decrease the cost by performing the accurate pressure control in the low pressure area by reducing the hysteresis width of the discharging pressure in the outstanding section area adjustment mechanism. CONSTITUTION:A pressure control valve 1 make the pressure value of the fluid to be controlled from a sensor 1a match to the set pressure value. The orifice diameter of an orifice 4 can be changed by a changeover valve 3. In the high pressure area of the pressure, a hand-operated changeover valve 3 is fully open. In the low pressure area, the valve 3 is closed and a flow path with the high conduit resistance by the orifice 4 is used to discharging air from a nozzle 5. The pressure loss by the orifice 4 makes the discharge pressure lower than the control pressure. Thus, the hysteresis width of the discharging pressure is decreased, enabling the accurate pressure control in the low pressure area. In short, the conduit resistance from the valve 1 to the nozzle 5 can vary, resulting in reducing an error due to the hysteresis width. |
