Patent ID: 9222594
Filing Date: 2015-12-29
Classification: F15B,F16K,Y10T

Abstract:
1. A directional valve for controlling an actuator by means of pressurized medium, wherein the directional valve comprises: a pressure port for pressurized medium; a work port for supplying pressurized medium; a tank port for receiving returning pressurized medium; and a body and a spool adapted to move axially inside the body of the directional valve, wherein the spool comprises a first position, in which the spool tends to be set, the spool further comprises a second position, into which the spool can be moved by a pilot control force and in which the spool is adapted to open a flow of pressurized medium passing from the pressure port to the work port, the spool further comprises a first channel that is connected to the work port when the spool is in the second position, wherein the first channel is shut off when the spool is in the first position, and a second channel that is connected to the tank port when the spool is in the first position, wherein the second channel is shut off when the spool is in the second position, the directional valve further comprises a feedback chamber in which pressure of pressurized medium generates a feedback force effective on the spool and opposite to the pilot control force, the spool is further adapted, in its second position, to guide pressure of pressurized medium of the work port to the feedback chamber, the feedback chamber is, when the spool is in the second position, adapted to generate the feedback force proportional to the pressure of pressurized medium of the work port and moving the spool to shut off the flow of pressurized medium, and the feedback chamber is placed around the spool between the body and the spool, the feedback chamber is delimited by the spool having a benching with an annular surface area formed around the spool and by the body having a benching with an annular surface area formed on an inner surface of the body, and the pressure of pressurized medium of the feedback chamber is effective on the annular surface area of the spool to generate the feedback force.