EXPANSION VALVE FOR A REFRIGERATION OR AIR-CONDITIONING CIRCUIT, AND METHOD FOR ACTUATING THE EXPANSION VALVE

摘要

The invention relates to an expansion valve for a refrigeration or air-conditioning circuit, comprising a control valve (11) with a flow housing (16) which has an inlet (52) and an outlet (58), an actuator (12), by means of which a control element (34) can be axially moved, and a first through-flow cross-section (50) between the inlet (52) and the outlet (58), said cross-section being delimited by the control element (34) and a valve seat element (46), wherein a blocking valve (70) is provided which is arranged fluidically between the inlet (52) and the control valve (11), and the blocking valve (70) has a closing element (72) and a closing element valve seat (74) which is arranged on the valve seat element (46) and which delimits a second through-flow cross-section (76). The closing element (72) has one axial end (82) which faces the inlet (52) and one axial end which faces the outlet (88), and the closing element (72) is arranged relative to the control element (34) such that in a first adjustment phase of the control element (34), the control element (34) moves axially relative to the closing element (72), wherein the second through-flow cross-section (76) is closed, and the closing element (72) axial end (88) facing the outlet (58) is connected to the inlet (52) via a third through-flow cross-section (84) which is delimited by the closing element (72) and by the control element (34), and in a second adjustment phase of the control element (34), the closing element (72) moves axially together with the control element (34), and the second through-flow cross-section (76) is opened.