CONTROL-VALVE PAIR MANUFACTURING PROCESS Russian patent published in 2001 - IPC

FIELD: hydromechanical engineering; distributors of miscellaneous hydraulic drives. SUBSTANCE: process includes making slot in casing and flat on control-valve shank, primarily installing control valve in casing and its locking in position relative to casing, making radial holes in casing and in control valve at a time, unlocking the control valve and extracting it from casing, making axial drillings on its shoulders in plane of radial holes, installing plugs in holes to form throttling edges, subjecting them to heat treatment, and finishing respective cylindrical surfaces of control valve and casing; after that control valve is installed in casing once more and locked in position relative to casing by means of cylindrical segment. Casing slot and shank flat are made by joint machining of control-valve pair after first installation of control valve in casing; outer diameter of control-valve shoulders and respective diameter of casing bore are measured upon removal of control valve from casing whereupon radial clearance between casing and control valve is measured; upon repeated installation of control valve into casing slot is made on flat surface of cylindrical segment in vicinity of its contact with control-valve shank, slot depth being equal to radial clearance obtained; then control valve is installed in casing again and locked in position relative to casing by means of cylindrical segment. Proposed process ensures centering of control valve in casing bore at the same time eliminating its circumferential movement. EFFECT: enhanced sensitivity and reliability of control-valve pair. 2 dwg