| In order to more directly obtain the material form and occurrence form of lunar soil water ice and the source mechanism of lunar water,various space powers are competing to carry out lunar soil water ice exploration missions in the lunar polar region.Based on the sampling mission of lunar soil water ice profile on the South Pole of Chang ’e-7 lunar probe,the design and analysis of the sampling drilling tool for the lunar lander profile are carried out in this paper.At present,rotary drilling and rotary impact drilling are the main methods for deep sampling of lunar soil.However,different from the dry lunar soil drilling objects faced by traditional sampling and return missions,the water ice in lunar soil has higher compressive strength,higher difficulty in crushing,and is prone to the phenomenon of water ice sublimation caused by stress and thermal disturbance,so it is difficult to ensure the fidelity of collected samples.Therefore,it is necessary to explore the design of cutting and crushing machines suitable for lunar soil water ice.In this paper,objective characteristics of lunar soil water ice as a special action object were analyzed,drilling and production strategies were formulated specifically,design principles were defined,multi-scheme configuration design of drilling tools was carried out,configuration parameter optimization and material selection of drilling tools were carried out,and scheme support was provided for the determination of lunar soil water ice sampling machines.Based on the Mohr-Coulomb shear failure criterion,and considering the influence factors such as drilling tool wear during drilling,a single tooth load model was established by analyzing the rotary cutting and pressing feed of drilling tool,and then the load model of rotary drilling of lunar soil water ice drilling tool was established by integrating.The influence laws of different drilling procedures,different lunar soil water ice parameters and different wear degree on the drilling load characteristics of drilling tools were obtained.Aiming at the function verification of the lunar soil water ice drilling tool,the development of the lunar polar low-temperature simulated environment test system was carried out,and the drilling performance test and drilling wear test were carried out by using the system.The drilling load characteristics under the influence of different drilling procedures and different parameter samples in the simulated low-temperature environment were obtained.By analyzing the form and degree of the drilling tool wear surface,The influence rule of drilling tool wear on drilling efficiency was obtained,the drilling ability of drilling tool was verified,and the service life of drilling tool was preliminarily predicted.In this paper,by carrying out the design of lunar soil water ice drilling tool in polar region and studying the drilling load characteristics,a kind of lunar soil water ice drilling tool with high efficiency,wide adaptability and low disturbance was developed.By theoretical calculation and experimental means,the influence law of different drilling procedures,different parameters of drilling objects and the degree of drilling tool wear on drilling efficiency was obtained.It will provide support for our country’s subsequent lunar water ice exploration missions. |
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