HYDRAULIC CIRCUIT FOR OPTION OF EXCAVATOR

摘要

PURPOSE: A hydraulic circuit for excavator option is provided to reduce manufacturing costs for a relief valve and to improve durability. CONSTITUTION: A hydraulic circuit for excavator option comprises a first hydraulic line(111), a second hydraulic line(112), a shuttle valve(115), a relief valve(118) and an option selection valve(120). A first hydraulic line supplies hydraulic oil to option from an option control valve(105) of a main control valve(100). The second hydraulic line collects the hydraulic oil, passing through option from the first hydraulic line, to the option control valve. The second hydraulic line offers the hydraulic oil to the opposite direction of the option. An inlet of the shuttle valve is connected to the first hydraulic line and the second hydraulic line. The option selection valve transfers the hydraulic oil flowing out from the option to the tank or the option control valve.