Design And Analysis On Reusable Latch Mechanism Of Cargo Ship Pallets

With the construction of the space station and the development of spaceexploration technology, The demand of space shuttles transport system oflocking-releasing-relocking large-size, heavy-duty supplies is becoming increasinglystrong, The mission of space operation platform releasing precision payload in-orbitwithout impact is increasing, Original disposable locking technology and pyrotechnicsunlock the device has been unable to meet current and future requirements of spacemissions. Therefore, develop the research of reusable latch mechanism in orbit hasbecome an urgent demand for space exploration activitiesThis paper aims at the functional requirement of cargo ship lock-release-relockthe pallets and payload, proposed a new type of latch hook-planar four-bar reusablelatch mechanism. This mechanism has lots of advantages, such as large carryingcapacity, the low impact of unlocking and the high reliability of locking andunlocking which benefit from the characteristics of the dead point of planar four-barmechanism, and it have the manually function for the astronauts to manually lock orunlock the mechanism under emergency situation.Pallets and payload must withstand vibration, shock, noise and other complexmechanical environment tests caused by the acceleration during launch of cargo ship.To ensure the reliable of the Connection between the pallets and payload duringlaunch, and the reusable latch mechanism can normal releasing and relocking thepallet after docking with the space station, This paper simulated the process oflocking-unlocking and analyzed the Bearing capacity of the reusable latch mechanism,so as to satisfy the quality and envelope sizes and other aspects of designrequirements, and reduce the costs of launch, improve the product reliability.To determine the locking scheme of Pallets and payload systems, firstly, thispaper determined the minimal locking point and the layout of reusable latchmechanism with the method of modal analysis and freedom analysis, and then usingthe finite element analysis software locking points Location optimized design enablesbaseband payload after locking up for the locking pallet proposed a space-savingduplicate lock-locking taper shaft combined solution. Based on the research，thispaper conduct the structural dimension optimization and topology optimization for the reusable latch mechanism. Then using finite element analysis software to lockingpoint location is optimized, so that the fundamental frequency of payload after lockingachieve the highest. Finally, according to the payload and cargo compartment scales,proposed the pallet system locking scheme use the horizontally placed reusable latchmechanism and tapered shaft.Based on the design and Analyze, this paper developed the pallet reusable latchmechanism prototype, and carried out the locking and unlocking function tests. By theprototype stiffness tests, obtained the curve of stiffness characteristics, and examinedthe design accuracy of the structural stiffness and strength. Build the vibration testsystems of the reusable latch mechanism and locking simulate payload, obtained thefundamental frequency characteristics of simulate payload and the dynamic responseof key parts, validated the system design specifications.