The Design And Virtual Prototype Simulation Study Of Internal Pneumatic Ejection Device

As a significant technology development trend for aircraft, stealth technology can significantly improve the survivability of plane. The external ejection device which is applied in traditional planes to eject suspension model, has many disadvantages such as high pneumatic resistance, poor stealth capability, therefore, internal ejection device with its own unique advantages, has become the mainstream means of the suspension model launching. According to the current domestic and overseas research status, combined with the specific design requirements of ejection device, this paper has carried out the relevant research work. The main research contents are as follows:(1)According to the specific ejection model separation pose parameters (separation speed, separation angular velocity and pitch angle) and the installation space of ejection device in the weapon bays, three sets of ejection device based on multi-link mechanism and four-bar linkage which use compressed gas as power source respectively for low speed, medium speed and high speed suspension model ejection are designed. The key parts (multi-link mechanism, upper and lower synchronous motion mechanism) of the ejection mechanism is particularly designed. In addition the motion state of ejection model suspension-release mechanism at the ejection stroke ends is analyzed, meanwhile hard limits and limit switches are designed to prevent the ejection mechanism from emerging "over-stroke" and make the whole mechanism reset;(2)The optimized3D digital models of the three sets of ejection mechanism are imported into ADAMS software with the application of Pro/E software. The virtual prototype dynamic simulation analysis of ejection mechanism is conducted. Then curves of various separation parameters during the ejection model separates from ejection device are respectively obtained. According to the simulation results, the self-release state when ejection model separates from aircraft and dead-point location of suspension-release mechanism are analyzed, verifying the validity of the designed ejection mechanism.(3) Through the virtual prototype simulation of ejection mechanism, the influence principle key parameters (air pressure, ejection model mass) to separation pose parameters when ejection model separates from aircraft is analyzed. The strength check of key parts (hard limit connection screw, linkage connection pin) is conducted. The results show that the strength of key parts satisfies the design requirement, and the influence of ejection mechanism by axial aerodynamic load is analyzed. The results verify that the axial aerodynamic load will not cause the axis movement of ejection model.The research work in this paper complies with the development trend of internal ejection mechanism, and the research results could provide certain directive significance for the design and study of internal ejection mechanism and its application in the interrelated field.