| With the rapid development of China's economy, the quickening pace of modernization and the continuous frequency and deepening of international cooperation, our country's manufacturing level is constantly improving. The requirements to all kinds of components of three dimensional plates are springing up continuously. As the three dimensional plates are applied to all walks of life, such as aerospace and aviation, vessel, train, urban construction, arts and crafts and so on, thus the technology of the forming of various kinds of plates obtains further development.The research on flexibility measurement stents of components for three dimensional surface sheet part is put forward for the measurement of the components of the three dimensional curved surface plates. Usually, the components of three dimensional curved surface plates have the characteristics of big dead weight and easy deformation. Therefore, in the support process of measuring its precision, if there is the case of uneven distribution of loading, the influence of component's dead weight will lead to deformation and change the whole component's curved surface, which result in the insignificant measurement. The flexible support discussed in this paper uses discrete idea to dissociate the continuous bearing surface of support into a series of suspension bars, independent respectively but controlled uniformly. Utilizing the equilibrium between each suspension bar and the basic element of each plate component to support the component to be measured evenly which will remain the curved shape under the free state.In this paper, during the course of designing, the surface of support adopts 1050mm×1050mm, with setting a suspension bar at every 150mm. There are seven rows and seven supports in each row. The thickness of the suitable component is from 2mm to 6mm and the material is aluminium alloy or steel. The research of the experience is as followed:1) Design one-way intake mechanism and differential intake mechanism and carry on the experiment. The pneumatic mechanism has several advantages of cleanness, cheapness, good adaptability to working environment and so on. However, there are still existing the shortages of amending output force at any time and the anelasticity of switching air pressure, especially when starting and stopping, the pneumatic mechanism will produce the phenomena of comparatively bigger inertia and no easy adjustment under low pressure circumstances. Combined with the pneumatic mechanism's characteristics and the most favorable operation atmosphere pressure and output force, the pneumatic mechanism would better employ the large-scale equipment with the bearing surface over 6m×6m, and the stroke over 400mm and the thickness of component plate to be measured over 15mm.2) Design concentration spring mechanism and mixed spring mechanism and carry on experiment. The spring mechanism has its unique advantage, that is, no matter tension spring, compressed spring, coil spring or concentration spring, their working ranges are all extensive and they can produce springs with several N and also the springs with dozens of N. They can better adapt to various sizes of flexible supports with special requirements to the components to be measured, that is, the components adapting to the fixed material and fixed thickness or the components with similar curved shape and bearing surface.3) Design electric buoyancy mechanism and carry on experiment. The main principle is to design based on the principle of utilizing the tank to displace the liquid to produce buoyancy with comparatively ideal experimental result. This structure is suitable for small and medium-size flexible support, which achieves the goal of this paper and designs for precise measurements of skins of the airplane and the train. |
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