HYDRAULIC CONTROL VALVE (OPTIONS) Russian patent published in 1997 - IPC

FIELD: hydromechanical engineering; hydraulic systems of miscellaneous mobile machines. SUBSTANCE: hydraulic control valve has a number of working sections, delivery and drain lines connected in parallel with respective delivery and drain inlets, load unit with control inlet connected to load line; each working section has at least one check valve connected at inlet to load line and at outlet, to working outlet of same section; load unit is, essentially, normally closed overflow valve whose control inlet is connected, in addition, to delivery line through throttle. In addition, it may be provided with double-line, three-position controlled normally closed valve with two opposite control inlets connected to different working outlets. It may be also provided with safety valve parallel to throttle. As an alternative, it may have double-line normally open controlled valve installed between load line and control inlet. It may likewise have two additional check valves installed in two load lines. Or else, it may be provided with two normally closed valves connected to outlets of check valves, its control inlets being connected to different working outlets. It may be also provided with normally open controlled valve whose inlet is connected to control inlet of load unit and outlet, to drain line; in this case, load unit is made in the form of controlled safety valve. As an alternative, it may be provided with normally open controlled valve installed in line additionally providing communication between delivery and drain lines; here, load unit is made in the form of noncontrolled safety valve. Load unit may be also made in the form of hydraulic feed controller of variable-delivery pump connected to load line and through throttle, to delivery line. EFFECT: enlarged functional capabilities. 9 cl, 10 dwg