Patent attributes
To reduce the amount of a liquid that remains in a boundary portion between a pressure receiving plate and a flexible member. Provides is a pressure control unit including a pressure chamber configured, at least a part of a wall forming the pressure chamber being formed of a flexible member; a flow inlet; a flow outlet; a pressure receiving plate, which is provided on an inner surface of the flexible member, and is to be displaced toward an inner side and an outer side of the pressure chamber; a valve member configured to open and close the flow inlet in accordance with the displacement of the pressure receiving plate; and an internal flow passage, which extends in a boundary portion between the pressure receiving plate and the flexible member along the inner surface of the flexible member, and is opened on a side surface of the pressure receiving plate.
