So convenient! The Mengtian experimental cabin is equipped with an \”electric door\”

Beijing Daily Client | Reporter Liu Suya Correspondent Yang Jing Wang Tianming Chen Yuan

On October 31, the launch mission of the Mengtian experimental module was a complete success. On the Mengtian experimental cabin, the 529 Factory of the Fifth Academy of the Aerospace Science and Technology Group manufactured a larger and more powerful electric outer door. This is the first \”automatic door\” in the history of my country\’s space vehicles, and it is also one of the first \”automatic doors\” in the history of the world\’s aerospace industry. For the first time, a sealed hatch with an electrically driven automatic switch is used in the space station. Its automatic opening function will provide a passage for the automatic exit of oversized cargo.

The \”electric door\” adopts a brand-new structure and mechanism design. It is the most difficult and longest-running hatch among the space station\’s hatches to develop. Different from traditional hatches with round and flat sealing structures, the electric outer hatch adopts a square and curved sealing structure for the first time, which brings multiple processing difficulties to hatch processing: the precision requirements of large-size curved sealing structures are higher, and the door The wall thickness and size differences across the body are greater, and the surface quality requirements in the rope groove are stricter.

The hatch manufacturing team selected a new process solution for the metal main body of the hatch. This process method is different from the previous hatch processing and forming modes and requires roll bending of large-thickness aluminum plates. In order to ensure the contour of the outer arc surface, technicians optimized the springback coefficient through simulation technology, determined the forming parameters through multiple rounds of iterations, and accurately controlled the forming deformation and springback conditions. Aiming at the difficulty of wall thickness differences in various parts of the door body, a flexible adaptive tool was designed, and finally realized high-precision contour processing of large-size curved surface sealing structures, overcoming the difficulties in the processing process.

The extremely high-strength non-metallic rope has become an important part of the door opening and closing – an important component of the rope traction mechanism. At the same weight, the tensile strength of this rope is 6 times that of ordinary steel wire. Using a rope to open the door, the design of \”flexible and rigid\” is indeed very special, but how to make this soft rope accurately pull the hatch movement without being tight or slack is a brand new challenge. Before assembly, the hatch manufacturing team calculated in detail the movement distance of each winding wheel in the rope system that drives the door to open and close, and obtained the tension change curve of the rope. At the same time, they designed a special traction rope tooling, and first carried out trial assembly outside the cabin. , after passing the test, the whole unit is transferred to the cabin for installation. After multiple rounds of iterative corrections, the precise control and installation of the double-layer linkage rope was finally achieved, so that both forward and reverse rotation of the drive component motor can exert force on the hatch, successfully realizing the automatic opening and closing function of the hatch.

When closing the door on the cylindrical surface of the Mengtian experimental cabin, the control of strength must be \”perfect\”. In order to not only meet the sealing requirements in the cabin, but also ensure smooth opening without jamming, it is necessary to strictly control the compression rate of the hatch sealing ring to ensure that its force is uniform. Through data simulation analysis of the sealing state of the curved surface, the technicians proposed a solution to match the sealing surface of the upper door frame and the door body of the cabin; in order to avoid the mechanism jamming caused by the misalignment of the upper and lower guide rails, the upper guide rail follows the door body. Determine the specific location along the trajectory of the lower guide rail.

In order to ensure that \”\”Electric door\” can be closed tightly without air leakage and opened and closed without lag in space. It must be tested and verified on the ground. During the 35 days of the test cycle, the test team repeatedly charged and released the pressure on the cabin. And the door opening and closing operation, a total of 450 cycles, the purpose is to simulate the space environment, verify the sealing performance of the electric outer door, and ensure that the \”electric door\” can be used well and safely in the space home.