Research On Material Removal Control Method Of Pneumatic Wheel Precession Polishing

The improvements of moulds’performances by using laser surface strengthening treatment also makes the subsequent processing more difficult, bring new challenges to the polishing technology. For the laser hardened mould surface, a new processing method called pneumatic wheel precession polishing technology is proposed to polish it efficiently. On the basis of the previous research of pneumatic wheel precession polishing technology, this paper will make a further study on how the material removal is controlled in the polishing process. For the low efficiency caused by the traditional dwell method, a new method called time-variant influence function is proposed to lower the process time. Pneumatic wheel precession polishing process is planned in detail based on time optimal planning. And machining simulation is used to testify its feasibility. The detail work is shown as follows:1) The method of time-variant influence function is proposed in the compute controlled polishing process. The dwell time method is introduced based on the surface error profile and the polishing tool influence function which is one-dimensional. Then for the purpose of receiving the shortest process time, a new method called time-variant influence function for material removal control is proposed. Finally, these two methods are compared based on the process time.2) The material removal process in the pneumatic wheel precession polishing is studied to reflect its high efficiency by using time-variant influence function. The two dimensional material removal process in the pneumatic wheel precession polishing is considered as a series of one-dimensional material removal process. Based on the influence function and surface error profile which is one-dimensional, the material removal process is analyzed by using the method of time-variant influence function, getting the time-variant removal capacity. Then simulation experiment is made to analyze the sensitivity of the parameters which determines the removal capacity of the polishing tool, in order to obtain the time-variant removal capacity by changing these parameters in the polishing process. When the calculated time-variant removal capacity exceeds the maximum value attainable, the material layers to be removed is polished layer by layer. Finally, line spacing stacking is used to make that the method of time-variant influence function is applicable to the two-dimensional material removal process in the pneumatic wheel precession polishing.3) In order to obtain the maximum polishing efficiency, the pneumatic wheel precession polishing process is planned in detail by using the method of time-variant influence function. The machining path is selected and the polishing trajectory is planned in the motion planning of the pneumatic wheel precession polishing process. The maximum moving velocity of the polishing tool is selected, and then the maximum removal capacity of the polishing tool is obtained by experiment. Finally, simulation is made on a generated surface error profile to prove its high efficiency and feasibility by using time-variant influence function.The results of this research have some significant theoretical guidance and technical reference value in improving pneumatic wheel precession polishing efficiency for the free-form mould surface.