Research On Technology Of Liquid Magnetic Abrasive Finishing Hole And Application In The Engine

As a common processing characteristic in the engine, surface quality of the hole has a significant influence on engine performance. For example, the nozzle inner wall quality has an important effect on the fuel atomization effect, the nozzle flow coefficient, fuel spray shape and degree of micronization, and then influences power performance, fuel economical efficiency and emissions of the engine. However, due to the small diameter and complicated shape of hole in the engine parts, it is difficult to finish the inner wall of hole through the conventional methods. For that reason, this paper adopts a new finishing device to finish the inner wall of hole based on liquid magnetic abrasive.This topic comes from the Natural Science Foundation of China (No.51075294) and the Natural Science Foundation of Shanxi Province (No.2010011034-1), named "Study on the Fluid Magnetic Abrasives Honing Technology". According to the character that liquid magnetic abrasive is free flow of fluid without magnetic field, and changes in the magnetic field, at meantime forms a flexible grinding layer with the processing ability along the process surface, we design a new type of hole finishing device based on liquid magnetic abrasive. The device can process the keyhole, shoulder hole, cross hole, special-shaped hole and thin pipe wall. The technology has the advantage of material removal rate controlled, high processing quality and convenient cleaning for hole after processing.This topic adopts the methods of theoretical analysis, experimental study and numerical analysis to study the technology of finishing hole with liquid magnetic abrasive. the main research contents are as follows:1) Study the rheological properties of liquid magnetic abrasive and the finishing mechanism of hole.2) Establish the material removal model of finishing hole by liquid magnetic abrasive.3) Design three new type devices of finishing hole based on liquid magnetic abrasive.4) Respectively to study the influence of processing time, magnetic field intensity, inlet pressure, abrasive particle size and other parameters on the finished surface quality of nozzle specimen, and analyses the finished surface morphology.5) Perform the experiment of performance testing on the4100QBZL engine burning emulsified diesel by changing the nozzle with different surface quality, analyses and study the impact of the finished nozzle on the power property, fuel economy, emissions and combustion of emulsified diesel engine.This paper deeply and systematically studies the processing mechanism and theoretical model of finishing hole by liquid magnetic abrasive. We through two aspects of theory and practice verify the feasibility that liquid magnetic abrasive can finish the inner wall of hole, prove the impact of the finished nozzle on the power property, fuel economy, the emissions and combustion of emulsified diesel engine, and propose a feasible way to solve the difficulty of finishing the inner wall of engine parts.