Valve and hydraulic system with the same

A valve comprising:

• a valve casing comprising:
• a valve casing body, a main valve bore extending in an axial direction in the valve casing body;
• and a first working port, a second working port, a supply port and a return port formed in the valve casing body;
• a main valve spool which is disposed in the main valve bore of the valve casing and which is slidable in the main valve bore to change the communication status between each of the first and second working ports and each of the supply and return ports, the main valve spool comprising:
• a main valve spool body, a main valve spool internal cavity extending in the axial direction in the main valve spool body;
• a main valve spool wall surrounding the main valve spool internal cavity;
• an inlet passage which passes through the main valve spool wall in a direction crossing the axial direction and which is configured for the second working port;
• and
• an outlet passage which passes through the main valve spool wall in a direction crossing the axial direction, and which has an inlet towards the main valve spool internal cavity and an outlet towards the valve casing body;
• and
• a counterbalance valve spool which is disposed in the main valve spool internal cavity of the main valve spool and which is slidable relative to the main valve spool between a first counterbalance valve spool position and a second counterbalance valve spool position, the counterbalance valve spool comprising:
• a counterbalance valve spool body;
• and
• a first counterbalance valve spool recess formed on an outer periphery of the counterbalance valve spool body,
• wherein in a state where the counterbalance valve spool is in the first counterbalance valve spool position, the inlet of the outlet passage of the main valve spool is closed by the counterbalance valve spool;
• and
• in a state where the counterbalance valve spool is in the second counterbalance valve spool position, the inlet of the outlet passage of the main valve spool is opened by the counterbalance valve spool through the first counterbalance valve spool recess of the counterbalance valve spool, so that the second working port is in communication with the return port through the inlet passage configured for the second working port, the first counterbalance valve spool recess and the outlet passage.