Abstract: A vaned spool type directional control valve used to change a direction of motion of an actuator in an air pressure or oil hydraulic circuit includes a vaned spool having a valve portion and a vane portion integrally formed on a spool shaft. A chamber including a shaft support portion, a valve room, and a vane room is formed corresponding to the vaned spool. Main ports connected to the valve room in the chamber and two vane ports penetrating the opposed sides of the vane room are formed in the directional control valve. The directional control valve is of a pilot operated type so that flow of fluid in a main circuit can be changed by rotating the vane spool using the pressure of a pilot fluid.

Abstract: A slide spool valve has a valve body formed by synthetic resin injection molding. The valve body includes a bore and an insert integrally coupled with the bore. The insert has a hollow portion penetrated by a port, the hollow portion being connected to the bore and having the same diameter as the bore and penetrated by one of ports. A valve room having a large diameter extends from an inner circumferential surface of the hollow portion to the penetrating portion of the port. The insert is manufactured by die casting and fixed in a metallic pattern of the valve body, so that it is integrally coupled with the valve body by insertion molding.

Abstract: A four-way reversing valve includes a valve casing having a plurality of ports through which fluid flows, a valve main body fixedly installed to the valve casing and having a valve chamber in which a plurality of main port connection holes for selectively connecting the ports are formed, a main spool rotatably installed at the valve chamber of the valve main body, for selectively connecting the ports according to a rotation position, and a spool driving unit for reversibly rotating the main spool by using part of fluid supplied through one of the ports in the valve casing. Thus, the number of welding points is minimized by incorporating the overall pilot valves and excluding additional capillary connection for the pilot valves. Also, manufacturing thereof is made easy and, during the manufacturing and use thereof, the rate of breakdown due to defective welding can be remarkably reduced.

Abstract: A vaned spool type directional control valve used to change a direction of motion of an actuator in an air pressure or oil hydraulic circuit includes a vaned spool having a valve portion and a vane portion integrally formed on a spool shaft. A chamber including a shaft support portion, a valve room, and a vane room is formed corresponding to the vaned spool. Main ports connected to the valve room in the chamber and two vane ports penetrating the opposed sides of the vane room are formed in the directional control valve. The directional control valve is of a pilot operated type so that flow of fluid in a main circuit can be changed by rotating the vane spool using the pressure of a pilot fluid.

Abstract: A four-way reversing valve includes a valve casing having a plurality of ports through which fluid flows, a valve main body fixedly installed to the valve casing and having a valve chamber in which a plurality of main port connection holes for selectively connecting the ports are formed, a main spool rotatably installed at the valve chamber of the valve main body, for selectively connecting the ports according to a rotation position, and a spool driving unit for reversibly rotating the main spool by using part of fluid supplied through one of the ports in the valve casing. Thus, the number of welding points is minimized by incorporating the overall pilot valves and excluding additional capillary connection for the pilot valves. Also, manufacturing thereof is made easy and, during the manufacturing and use thereof, the rate of breakdown due to defective welding can be remarkably reduced.