Hydraulic Steering Valve Safety via Stop Valve and Feedback Suppression
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Solution Overview
Problem
Hydraulic steering systems with power-assisted steering valves face safety issues due to unintended activation caused by leaks, leading to potential damage or operator irritation from undesired feedback reactions.
Innovation Solution
Incorporating a hydraulic drive with a pilot valve arrangement and a stop valve to limit pressure and interrupt fluid supply, along with a feedback suppression device that prevents pressure feedback between the steering motor and unit, ensuring safe operation and reducing unwanted movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydraulic steering valve is used with power assisted activation, then steering activation is achieved, but leakages cause unintended activation and safety risks
Solution Approach 1:
A stop valve is introduced as an intermediary component between the pressure control valve and the pilot valve arrangement. This stop valve selectively interrupts the hydraulic fluid supply to the pilot valve arrangement, preventing unintended steering valve activation caused by leakages while allowing proper activation when needed.
Solution Approach 2:
The pressure control valve preliminarily limits the maximum pressure supplied to the pilot valve arrangement before the steering valve activation occurs. This pre-pressure limitation prevents excessive pressures from causing unintended valve displacement due to leakages.
2Adaptability or versatility
If a steering unit with feedback behaviour is used in parallel to the steering valve, then steering flexibility is improved, but feedback reactions cause undesired steering member movements
Solution Approach 1:
A feedback suppression device is introduced as an intermediary component in the hydraulic circuit between the steering unit and the steering motor. This device selectively suppresses feedback reactions from the steering motor to the steering unit, preventing undesired steering member movements while maintaining steering flexibility.
Solution Approach 2:
The feedback suppression device dynamically controls the feedback behavior based on the activation state of the steering valve. When the steering valve is activated, the feedback suppression device activates to prevent feedback reactions; when the steering valve is not activated, feedback behavior is maintained for normal steering operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Significantly improves safety by minimizing leakage risks and eliminating involuntary steering valve activation, while allowing optional steering modes and providing symmetrical steering behavior, thus enhancing operator safety and reducing potential damage.
Implementation Method 1
the steering valve has a hydraulic drive with a pilot valve arrangement supplied by a pressure control valve
Implementation Method 2
a stop valve being located between the pressure control valve and the pilot valve arrangement
Implementation Method 3
a feedback suppression device being located in a path between the steering unit and the steering motor, said feedback suppression device preventing a feedback of pressures at the steering motor on the steering unit
Data Source
AI summary
The invention concerns a hydraulic steering (1) with a steering valve (7) located between a supply connection arrangement (P, T) and a steering motor (2). It is endeavored to improve the safety of such a steering. For this purpose, the steering valve (7) has a hydraulic drive (9, 10) with a pilot valve arrangement (11) supplied by a pressure control valve (5), a stop valve (16) being located between the pressure control valve (5) and the pilot valve arrangement (11).