Study On Feeding And Recycling Method In High Speed Machining Fixture For Paper Honeycomb Part

Compared with conventional fixture methods, the proposed method, based on magnetic fields and tribology theory, has many excellent characteristics such as credible fixture, convenient operation, pollution free, low cost, etc. The machining efficiency and precision of paper honeycomb core part can be improved greatly through applying the method. As a key technology in the fixture system, study on numerical control feeding technology and recycling method is a very important work in order that the novel technology is used in practice. In this dissertation, by coalescing theory analysis and experiment study, feeding and recycling method in fixture system of paper honeycomb are studied systemically. Seven chapters are included in this dissertation:The state of the art in honeycomb composite material and its application in the airplane manufacturing are expounded firstly in chapter 1. Then the existed fixture methods of honeycomb, feeding and recycling methods are summarized. After that, the significance and purpose of studying on the feeding and recycling method are proposed. Finally, the main contents of this dissertation are summarized.The qualitative relationship between flow properties of bulk solids and its characteristics is studied in theory in chapter 2. Then quantitative relationship between vibratory acceleration and hole-size are studied when 80 meshes iron powder flow out from small holes. Furthermore, the relationship between discharges of iron powder and flow time, the relation between discharge rate and vibration frequency, and the relation between discharge rate and vibratory amplitude are also studied by means of experiments, and a graph representing the variational relation among these parameters is made. A solenoid electromagnetic switch is designed through theoretical calculation, then the relationship between magnetic force and air-gap distance, and the relationship between magnetic force and current intensity are studied by experiment. These experimental data are basis of vibratory feeder design.The component structure and working principle of vibratory feeder, driver system and pre-compaction equipment are developed in chapter3. A vibratory feeder that can control discharge of iron powder quantitatively is designed based on working conditions and experimental results. When the honeycomb core parts in a certain model plane are considered as the objects to be fed, a double housing driver isdesigned based on modern design theories and methods. In order to make the surface of honeycomb touch with the platform completely, a pneumatic pre-compaction project is presented.In chapter 4, with regard to the structure characteristics of honeycomb core part, a global G1 continuous compound surface model construction method is presented from the point of view of surface continuity and manufacturability. Then the planning method of feeding region is studied based on mathematic model of part and demand of working conditions. And an optimized selection method of feeding region is proposed.In chapter 5, the control system and control software of feeder are developed. By applying the classical control theory and simulation software MATLAB, the dynamic characteristics of motion along X and Y direction are described in detail.Based on gas-solid two-phase flow theory, a separating technology of mixture composed of iron and paper scrap is studied in chapter 6. Applying gas-solid two-phases suspended flow theory, the force condition is analyzed when two kinds of material separate at the corner of the pipe. Then the selection and calculation method of system design parameters is described detailedly.In chapter 7, systematical summary is given, and future work is put forward.