Fluid control device

A fluid control device for controlling a flow of a fluid, the fluid control device comprising:

• a flow path having an inflow port and an outflow port, the flow path being configured to allow a controlling fluid to flow along the flow path;
• a valve body arranged in the flow path between the inflow port and the outflow port;
• a valve seat on which the valve body can be seated;
• an elastic member for urging the valve seat or the valve body in a direction of approaching or separating the valve body to or from the valve seat;
• and
• a working fluid chamber that expands or contracts in the direction of separating or approaching the valve body from or to the valve seat by feeding or discharging a working fluid;
• wherein a part of the valve body is present on an extension line of a linear flow path central axis on the inflow port side across the valve body and the valve seat, and on an extension line of a linear flow path central axis on the outflow port side;
• and
• wherein the valve seat or the valve body is displaceable in at least one axial direction of the linear flow path center axis on the inflow port side and the linear flow path central axis on the outflow port side.