Mechanical-hydraulic aircraft nose wheel turning anti-swing system

Abstract

The invention discloses a mechanical-hydraulic aircraft nose wheel turning anti-swing system, and aims to provide a multifunctional combination valve integrating reversing, damping, compensation and state conversion. The mechanical-hydraulic aircraft nose wheel turning anti-swing system is realized through the following technical scheme: the high-pressure oil is divided into two paths by an electromagnetic valve; one path is sent to a state conversion valve through a reversing valve; enters a safety valve to control an airplane front wheel turning actuator cylinder to overcome the state change-over valve spring force to allow the stating change-over valve to be in left-position machine energy, the change-over valve communicates with two cavities of an air aircraft front wheel turning actuator cylinder, the two cavities of the turning actuator cylinder are cut off by a one-way damping valve, and the other path of the turning actuator cylinder enters a swing-reducing oil return compensator through a closed-loop swing-reducing hydraulic loop connected beside an electromagnetic valve hydraulic pipeline; when the electromagnetic valve is powered off, high-pressure oil communicates withthe reversing valve, enters the shimmy damping oil return compensator through a bypass pipeline and communicates with the state change-over valve, the reversing valve and two cavities of the front wheel turning actuator cylinder are cut off, two cavities of the turning actuator cylinder communicate with the one-way damping valve, and the airplane front wheel is controlled to be in a shimmy dampingmode through the safety valve.

Description

technical field [0001] The invention relates to a mechanical-hydraulic aircraft nose wheel turning anti-swing system. Background technique [0002] The aircraft hydraulic system is an important part of the aircraft, which is directly related to the smooth flight and safe landing of the aircraft. Important actions such as rudder surface control, front wheel steering, landing gear retraction, etc. are all performed by it. Aircraft landing gear front wheel control technology is the key technology for modern aircraft to achieve ground control, which is directly related to the safety of aircraft takeoff and landing. Everyone knows that the nose wheel steering system is to provide directional control of the aircraft on the ground. There are two input sources for turning, one is the turning handwheel and the other is the rudder pedals. The turning range controlled by the turning hand wheel is relatively wide. The maximum stroke can control the front wheel to turn left and right 7...

AI Technical Summary

Problems solved by technology

The function of the compensator is to prevent the system from being impacted, but the system has the following disadvantages: due to the long-distance arrangement of tie rods, rocker arms, cables, and pulleys, the system has invalid strokes, poor operability, and large operating force; there are many accessories and parts. Heavy weight; complex installation and adjustment, difficult maintenance

When installing the mechanical-hydraulic turning system, factors such as the position of each mechanical connection point and the pre-tightening force of the steel cable must be considered. If the adjustment is not good, the zero position of the system will be affected.

For a long time, the front wheel turning anti-sway system of the aircraft has repeatedly encountered the problem of front wheel deviation. The reason is that the mechanical-hydraulic front wheel turning anti-sway system used in the aircraft has an inherent failure mode, which will inevitably occur under certain conditions. Can cause the problem of front wheel deviation

The mechanical-hydraulic front wheel turning anti-sway system integrates the reversing valve and the state switching valve into one part, resulting in no distinction between the function authority of the reversing valve and the oil circuit for turning and sway reduction. When the reversing valve is not centered When entering the swing reduction state, the actuator will form a dead space, resulting in the front wheel being locked, so that the swing reduction and brake correction will not work; in addition, the mechanical-hydraulic front wheel turning anti-swing system does not reduce Swing back oil compensator, oil supplement valve, safety valve, oil return control valve, etc., in order to ensure the safety of the system when the unloading valve fails, a safety valve is installed in the circuit; the safety valve converts the hydraulic power of the passing oil into heat, causing The oil temperature rises, the system performance decreases, and seriously affects the service life of the oil pump

If the oil return is completely cut off for a long time, due to thermal expansion and cold contraction, the pressure of the anti-sway system of the front wheel steering may be too high, which will affect the safety of the aircraft.

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