Robert Boschgmbh

Holger Lueues

Werner Schumacher

Hartmut Sandau

Hartmut Sandau, Deceased

Rainer Trucksess

An electro-hydraulic control device (,) for a hydraulic servo motor for controlling a volume flow is proposed, which is embodied as a 4/2 valve module. A blocking valve in accordance with seat valve technology between a motor connection (B) and a return flow (R) form a lowering element (,), while the associated unblocking member (,) is designed as a longitudinal slide (,), which controls the connection between an inflow connection (P) and a motor connection (A) and is actuated by a proportional magnet (,). After unblocking the blocking valve, its seat valve body (,) is mechanically taken along by the longitudinal slide (,), and the two volume flows are proportionally controlled via the lowering element (,) and the lifting element (,), so that a large switching capacity is achieved along with a construction with few leaks.

Electrohydraulic control device

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

A control device for a volume stream of a hydraulic working medium has a blocking valve having a seat valve body cooperating with a stationary main valve seat, a pre-control valve member arranged in the seat valve member and cooperating with a valve seat provided with the seat valve member, an actuating device with which the pre-control valve member is in an operative communication, a spring providing a force with which the pre-control valve member cooperates with the valve seat and controls a pressure in a pressure chamber formed in the seat valve member and a valve housing. The seat valve member is pressed against the main valve seat under the action of the pressure, a pressure chamber for a working medium is formed, a throttle point with a constant cross-section communicates the pressure chamber between the seat valve body and the valve housing constantly with the pressure chamber of the working medium, a variable throttle point connects the pressure chamber between the seat valve body and the valve housing with a container. The variable pressure point has a cross-section which is changeable by the pre-control valve member. The actuating device which cooperate with the pre-control valve member is formed as a proportional magnet mounted on the locking valve.

Growing community of inventors

Vaihingenenz, Germany

Holger Lueues