Experimental Study On Electrolytic Modification Of Intersecting Hole

The traditional machining process inevitably leaves burrs on the surface of parts.The existence of burrs will directly affect the performance and life of mechanical parts.Considering its complex structure,it is difficult to remove burrs.To make sure the quality of intersecting holes,an effective method of removing burrs is needed.Electrochemical machining technology is to make the anode gradually dissolve in the electrolyte under the condition of external power supply through the electrochemical principle.Then obtain the expected morphology by designing and changing the cathode structure.It is widely used because it is not in directed contact with the workpiece and the workpiece does not reduce deformation and stress.At present,electrochemical machining deburring is one of the common methods of cross hole deburring,but few people have studied the morphology of the modified surface after electrochemical machining.In this paper,the fuel injection body is used as the test object.The electrochemical machining test device was built to complete the research on the morphology of the deburring modified surface at the intersection of cross holes.The main research contents are as follows:(1)Design of electrolytic modification machining system and test scheme for intersecting holes.According to the structure of fuel injection,a machining device was built to complete the electrolytic modification test at the intersection of cross holes.The method of testing the shape and radius of the transition arc at the intersection of the intersecting holes are determined.They lay a foundation for the experimental study of electrolytic modification of intersecting holes.(2)Structure optimization and test verification of electrolytic modified cathode at the intersection of cross holes.According to the complex structure of the intersecting hole,a suitable cathode structure(cylindrical,stepped and intersected)was designed.The mathematical model and geometric model of machining process are established,and complete the process model solution.By analyzing the changes of electric field distribution of different cathode structures during electrochemical machining,the morphologies of the transition arc at the intersection of the intersected holes after machining and the distribution of the electric field equipotential lines before machining,it is found that the morphologies of the transition arc obtained after electrochemical machining of the intersected cathode structure are the best.Finally,the solution result of the model is verified by the process test,then the intersecting cathode is determined as the cathode structure to be explored in the subsequent test.(3)Solve the model of electrolytic machining process at the intersection of cross holes.Based on the cathode structure above and the solution model of processing process.The processing voltage(U)and processing time(t)were taken as independent variables,and the transition arc radius at the intersection of the intersecting holes was taken as the dependent variable.The influence of independent variable on dependent variable is analyzed by numerical solution of machining process model.By analyzing the morphology and radius of the transition arc obtained by the model,the simulation parameters of R=2±0.2mm transition arc radius were determined:when machining voltage U=10V,processing time t=420s and 480s;When the processing voltage U=12V,the processing time t=360s,420s;When the processing voltage U=14V,the processing time t=300s and 360s;When the processing voltage U=16V,the processing time t=300s.It provides reference for the follow-up electrolytic modification test.(4)Experimental study on the machining process of electrolytic modification of intersecting holes.Based on the cathode structure above and the test scheme,a single factor test was carried out.The transition arcs under different technological parameters were prepared by electrolysis test.Then cheak and sort it out.By analyzing the morphology and radius of the transition arc obtained by the test,the simulation parameters of R=2±0.2mm transition arc radius were determined:When the processing voltage U=10V,processing time t=360s and 420s,480s and 540s.When the processing voltage U=12V,the processing time t=360s;When the processing voltage U=14V,the processing time t=300s.(5)Study on the law of electrolytic modification of transition arc of cross hole.Firstly,The boundary data of anode after electrochemical machining is obtained by numerical solution of machining model with different processing time(t),different processing voltage(U),and different processing gap(?).Then,the relationship between independent variables and dependent variables was coupled by the least square method.The regression equations of ternary polynomial between the processing time(t),the processing voltage(U),the processing gap(?)and the radius(R)of the transition arc are established.The forming law of transition arc radius at the intersection of cross holes is obtained.Finally,The Meshgrid function and Patch function are used to complete the three-dimensional coupling of machining area(transition arc of cross hole).The 3D shape fitting of the modified surface at the intersection of the intersecting holes was completed.