摘要:
In order to continuously change the transmission ratio between power-assisted steering mode and emergency steering mode and to maximize the flow of hydraulic oil in the power-assisted steering mode when the steering wheel is rapidly turned, a steering assembly is proposed which uses a common line which bypasses the metering pump, as a supply line for flow amplification during power-assisted operation and as a return line for changing the transmission ratio during emergency operation. This common line is connected to selected supply lines by way of throttles and with corresponding cylinder lines or with all cylinder lines by way of throttles. Steering devices of this type are employed in mobile equipment, in particular in slowly moving vehicles.
摘要:
The invention changes over to another steering ratio automatically and very safely on the transition from servo to emergency operation. In the steering system, only a few of the lines (13) link the metering pump (10) to one of the cylinder connections (7, 8) and in each of the other lines (13') there is a changeover unit (16) which also links the lines (13) to the cylinder connections (7, 8) or the delivery connection (6) depending on the method of operation. These steering systems are used in mobile systems, especially slow-moving vehicles.
摘要:
A steering system having a first auxiliary branch line (23, 24) connecting a main line (6) to a return port (12); with a load line (22) connecting the first auxiliary branch line to a load port (13) and dividing the first auxiliary branch line into first (24) and second (23) flow paths. The main line includes an adjustable input throttle (20). The first flow path (24) includes an adjustable load throttle (27) and a second throttle (26) in series. The adjustable input throttle and the adjustable load throttle act in a same direction. The purpose of this control circuit is to raise the load port pressure level, so as to prevent relatively high power losses.
摘要:
Conventional steering systems of this type have the disadvantage that the dynamic load signal flow is lossy which has a negative effect on the energy efficiency. Another disadvantage arises in steering systems with a closed-center design. When the steering cylinder is pulled by an external force, the steering cylinder moves in advance of the apportioned steering flow. In the present novel steering system, the adjusting angles of the primary adjustable throttles (12, 13, 14, 15, 16, 17) are matched in a novel way, so that in a steering range where the steering rotational speed is limited, the load signal flow is used for actuating the steering system. In this phase, the steering system then operates according to the open-center principle.