Research On Non-Self-Locking Thread Connection Space Unlocking Device

Non-firework unlocking device has become an important research direction of space unlocking device because of its advantages such as reusable,no pollution,small impact and easy storage and transportation.The non-self-locking thread connection space unlocking device is a new kind of space unlocking device which realizes the connection and separation by using the trigger mechanism to restrict and remove the non-self-locking thread connection.In this paper,the unlocking mechanism and unlocking performance of the space unlocking device of non-self-locking thread connection are analyzed theoretically and verified experimentally.Based on the force analysis and energy conservation law of the space unlocking device with non-self-locking thread connection,the unlocking moment equation of the device and the energy(motion)equation of the unlocking process are derived.The unlocking process of the device is analyzed based on the energy(motion)equation of the unlocking process,and the results show that the unlocking speed when impacted by the loading nut only is higher than when impacted by the loading spring only,and the unlocking movement interferes with the interaction of the joint action.The structure design and thread parameter selection of 90 k N non-self-locking thread connection space unlocking device are completed,and the static strength analysis of the main components of the device is carried out.The energy(motion)equation of 90 k N non-self-locking thread connection space unlocking device under different working conditions was calculated.The results show that the unlocking time is 0.0202 s when impacted by the loading nut only.When impacted by the loading spring only,the unlocking time is 1.00 s,1.23 s and 1.53 s when the loading spring compression is greater than,equal to or less than the screw length.For the joint action of loading nut and loading spring,the unlocking time is 0.18 s.Unlocking test was carried out on the prototype of 90 k N non-self-locking thread connection space unlocking device,and the unlocking time was about 0.045 s when impacted by the loading nut only.The unlocking time is about 1.02 s when impacted by the loading spring only.For the joint action,the unlocking time is about 0.400 s,which is close to the simulation results.The vibration and impact simulation was carried out on the unlocking process of the device,and the maximum impact load of the device when impacted by the loading nut only was 500 g.The vibration and impact test was carried out on the unlocking process of the prototype,and the maximum impact load in the whole time domain was 204.78 g when the preloading force imposed on the loading nut was 38.15 k N.According to the relationship curve between preloading force and tightening moment in the preloading force calibration test,the maximum impact load in the whole time domain is about 483.09 g when the preloading force imposed on the loading nut reaches 90 k N,which is in line with the simulation results.The thermal deformation analysis of the device shows that the maximum deformation of the flywheel nut and the load-bearing screw of the device at 70℃ is 0.4900 mm and0.2640 mm respectively.At-70℃,the maximum deformation of the flywheel nut of the device is 0.0464 mm,and the maximum deformation of the load-bearing screw is0.0829 mm.Unlocking performance tests at high and low temperatures show that the prototype can unlock smoothly at ±70℃.