A stability control augmentation system and method for a flight control surface of an aircraft. The system includes s an actuator operable for actuating the flight control surface, and a control valve comprising a spool and an integrated augmentation mechanism. The spool and the actuation mechanism are both moveable to open and close a fluid flow path through the control valve to control the actuator.

A working valve section for a sectional fluid control valve comprising a valve section housing having a substantially planar surface for being attached to an adjacent valve section housing; a main control spool bore (43) extending into the housing substantially parallel to the planar surface; a compensator spool bore (46) extending into the housing substantially parallel to the planar surface, the compensator spool bore being spaced from the main control spool bore; a first relief slot (49a) extending across the planar surface substantially coextensive with the main control spool bore; and a second relief slot (49b) extending across the planar surface substantially coextensive with the compensator spool bore.

Disclosed is a flow control valve for a construction equipment for controlling the amount of oil supplied to a hydraulic actuator from a hydraulic pump. The flow control valve for the construction equipment, according to the present invention comprises: a valve body installed on the path between a hydraulic pump and a hydraulic actuator and configured with a supply path communicating with a pump path supplying the hydraulic oil from the hydraulic pump and the actuator ports connected to the hydraulic actuator; a switchable spool provided within the valve body; a pressure chamber provided within the spool, which communicates with the supply path and the actuator port on one side; a signal pressure path provided within the spool, which communicates with the actuator port on the other side and the pressure chamber; and a flow control valve provided within the pressure chamber, wherein when the pressure of the hydraulic oil returning to the hydraulic oil tank from the hydraulic actuator exceeds the predetermined pressure, the flow control valve is switched by the returning oil supplied through the signal pressure path and blocks the opening part.

A poppet valve includes an inlet port, a first outlet port, a second outlet port, a first exhaust port, a second exhaust port, and a spindle. A first poppet element and a second poppet element each float relative to the spindle. A first piston and a second piston are fixed relative to the spindle. The spindle moves from an initial centered closed position to a first actuated position or a second actuated position to direct air flowing from the inlet port to the first outlet port or the second outlet port, respectively. The initial centered closed position is located between the first actuated position and the second actuated position. A housing contains the spindle, the first poppet element, the second poppet element, the first piston and the second piston.

A direct drive valve for controlling fluid flow, includes a flow spool operable to control fluid flow through the direct drive valve; a control spool located within the flow spool and an actuator operable to drive the control spool relative to the flow spool. The direct drive valve is configured such that in use movement of the control spool relative to the flow spool causes the flow spool to be actuated by fluid pressure.

A working valve section for a sectional fluid control valve comprising a valve section housing having a substantially planar surface for being attached to an adjacent valve section housing; a main control spool bore (43) extending into the housing substantially parallel to the planar surface; a compensator spool bore (46) extending into the housing substantially parallel to the planar surface, the compensator spool bore being spaced from the main control spool bore; a first relief slot (49a) extending across the planar surface substantially coextensive with the main control spool bore; and a second relief slot (49b) extending across the planar surface substantially coextensive with the compensator spool bore.

A hydraulic valve includes: a valve main body; and a spool. Further, the spool is provided with a main passage portion, a first passage portion communicable with a first port, and a second passage portion communicable with a second port, an opening area of the first passage portion with respect to the first port is changed and flow rate control of oil from the first port to the second port through the main passage portion is performed, and the main passage portion of the spool has a first region, a second region, and a third region that connects the first region and the second region, an inner diameter of the first region being formed larger than that of the second region, and the third region being formed in a tapered shape in which an inner diameter gradually decreases toward the second region.