Efficient Softness Abrasive Flow Precision Machining Method And Its Measurement And Control System

The mold is an important equipment for industrial production, which is an importantguarantee for the development of the high-tech industry for large quantity use and wide influence.In modern industrial production, more than60%industrial products require the use of the mold.The structural surface mold limits the contact of traditional polishing tool and the machiningsurface. Abrasive flow machining method will destroy the structural surface because of thestrong resistance of strong viscosity. Abrasive reciprocating motion can not do random grinding,limiting its application for mirror level surface roughness in ultra precision machining. Softabrasive flow machining method can utilize the turbulent random guiding abrasive randomgrinding. In order to improve the efficiency of soft abrasive flow machining, it is necessary toput forward an efficient method and measurement and control system, with separation, highpressure driving method, and the whole process monitoring.The soft abrasive flow processing method was studied. Liquid and particle motionsimulation and analysis were made. The movement form of liquid has two functions. On onehand, normal stress and tangential stress is applied on the wall surface; on the other hand, themovement of liquid motion is also a major energy source to determine the particle movement.Abrasive particle influences multiphase flow with particle mass loading rate, particle momentumload rate and the particle volume fraction of which10%and50%are boundaries for differentabrasive flow. Oil has great wall pressure and shearing force, more likely to cause damage ofwall structure, is suitable for the finishing of rough machining stage for a large number ofmaterial removal. Water is suitable for the finishing of fine processing stages. Large diameterabrasive speed gain is larger, suitable for the finishing of rough machining phase. The smallerdiameter abrasive can maintain speed in longer distance, which is conducive to the continuouscontact with workpiece surface protrusions for fine processing stages. Wall turbulence kineticenergy is not zero, which can guide the abrasive doing random cutting and improve the surfaceroughness. Abrasive material removal and surface roughness increase depend on differentdiameter of the abrasive grain. Small diameter abrasive follow liquid flow better with random micro cutting in favor of roughness improve. Large diameter abrasive long time scraping on wall,with collision frequency more than small diameter abrasive, can lead to better material removalrate.Comprehensive analysis of soft abrasive flow processing method and measurement andcontrol system was undertaken. Discussion of soft abrasive flow of all sorts of efficientprocessing methods, and the separation feeding method and device were described in detail.Embedded real-time operating system and task switching of measurement and control systemwere illustrated in detail. Solid-liquid separation is more efficient than solid-liquid mixing way,which can reduce the pressure waste and the pump body damage and improve the outputpressure to above of20MPa. Separate feeding method enables particle concentration control, toimprove the efficiency of processing. Using CAN bus and embedded real-time operating systemcan guarantee the real-time of control tasks. By using the fuzzy control, the output flow is stableat6%. With autonomous control method, the reliability of the system is greatly improved. Liquidflow volume and particle concentration are automatically adjusted by section, meeting theprocessing needs.The soft abrasive flow experiments were studied. Power source and the fluid sourcecoherence relation were established. The application relationship of fluid pressure, flow volumeand power were derived. Energy demand of work flow channel is high pressure, high speed andsmall flow types. During the delivery of liquid medium, centrifugal pump and gear pump arebetter. Transportation of solid medium needs the diaphragm pump to meet the requirements.Experimental results show that, the soft abrasive flow machining roughness can now reach0.06μm. Through continuous imaging particle motion trajectory and randomness are proved.Experimental results show that, using an efficient processing method and measurement andcontrol system the efficiency is increased by40%.