Robert Boschgmbh

Hartmut Sandau, Deceased

Werner Schumacher

Holger Lueues

Rainer Trucksess

A hydraulic circuit in a monoblock structure for lifting and lowering a load has at least two electromagnetically actuatable proportional distributing valve elements, a check valve, a pressure balance for load-independent lifting of the load as an input element, a housing accommodating at least some of the elements and having at least one pump connection, at least one consumer connection, and at least one return connection, the proportional distributing valve elements being disposed parallel to one another, electromagnetic drives seated side-by-side on a same side and at a same height, the pressure balance having a piston which is disposed coaxially next to a longitudinal slide of a first one of the proportional distributing valve elements in a bore that guides and supports both the valve elements, the longitudinal slide of the first proportional distributing valve elements being spring-loaded, and at least one component for adjusting a prestressing and bracing of a spring on the housing of a control penetrating the piston of the pressure balance.

Hydraulic control in monoblock structure for lifting and lowering a load

An electrohydraulic control device (10) for a double-acting consumer (11) is proposed, in which a continuous volumetric flow control to and from the consumer (11) is possible with two proportional 4/2-way magnet valves (12, 13), each with one seat valve function (26), and by means of two blocking valves (29, 38) of the seat valve type; free floating is attainable as the fourth work position. The magnet valves (12, 13) are structurally identical and are each connected into the volumetric flow to the consumer and the volumetric flow leaving the consumer; each consumer connection (28, 36) is sealed off tightly by a seat valve function (26) of the magnet valves (12, 13) and a blocking valve (29, 38). The magnet valves (12, 13) have a main control member (57) and a pilot control member (58), which cooperate in the manner of a followup controller and make do without a separate control oil supply, so that high hydraulic capacities can be controlled continuously and with short response times.

Growing community of inventors

Schwieberdingen, Germany

Hartmut Sandau, Deceased