HYDRAULIC SYSTEM FOR DRILLING MACHINE FEED DRIVE Russian patent published in 1999 - IPC

FIELD: mining industry. SUBSTANCE: system relates to hydraulic systems of drilling machines, including those used in construction industry for building of cast-in-place piles. Hydraulic system has pump, drilling carrier feed hydraulic cylinder, drilling thrust and speed regulator, hydraulic control valves. One of hydraulic control valve connects rod space, and second hydraulic control valve connects piston space of hydraulic cylinder and regulator either with pressure line or with return line of pumping station. Regulator is made in the form of spring-loaded valve with pressure handle. Pressure at inlet bore of this valve is proportional to value of force applied to handle. Hydraulic control valve has its outlet bore connected with rod space of hydraulic cylinder and is hydraulically controlled. Hydraulic control working chamber is connected with piston space of hydraulic cylinder by means of relief valve, and it is connected with return line by means of throttle unit. Working spaces of hydraulic cylinder are connected to each other through two valves which are engaged successively. Working spaces of these valves are connected with rod space and piston space of hydraulic cylinder. Aforesaid arrangement of hydraulic system ensures less power loss and reduced heating of hydraulic components, as well as allows for reduction of installed power of drilling carrier feed drive due to higher efficiency of system in all modes of its operation. EFFECT: higher efficiency. 3 cl, 1 dwg