Papers by Author: H.L. Chen

Abstract: At present, crankshafts are finished mostly by abrasive cloth and manual steel brush, which is not ideal on finishing quality, efficiency and cost, especially cleanness degree does not meet design and use request. So a new horizontal spindle barrel finishing for crankshafts has been developed. To contrast the finishing effect, surface geometric characteristic, physical-mechanical property, cleanness degree etc. are analyzed, which indicates this process can comprehensively improve the surface integrity of crankshafts’ part. Simultaneously, this process can decrease cost, reduce labour intensity, improve efficiency, and easy to automation. Its application has wide economic and social benefits.

Abstract: In the paper, polishing free-form surfaces of die are studied with magnetic abrasive finishing. The principle of magnetic abrasive finishing free-form surface, the design of magnetic pole, the composition and categories of magnetic abrasive are introduced. Through digitizing of free-form surface by using trimmed NURBS, based on residual roughness, machining accuracy and other parameters, the offset variable of free-form surface, which is the path of magnetic pole, is derived with the computer aided geometric design theory. These will provide theoretic foundation for the realization of finishing free-form surfaces of die automatically.

Abstract: To internal magnetic abrasive particles surface finishing, the motion of magnetic abrasive particles was influenced not only by the intensity of magnetic induction, but also by the internal diameter, and the magnetic inductive capacity was also an important factor that influences finishing quality. In this paper, under the same experimental conditions, electromagnetic field and permanent magnetic field were respectively used to magnetic abrasive particles surface finishing on thin stainless steel bush and 45 steel bush, new thoughts on inserted permanent magnetic pole and butted permanent magnetic pole were pointed out. The finishing quality of two kinds of work pieces under three different magnetic poles was compared. The results have shown that permanent magnetic pole could decrease the surface roughness Ra of work piece from 1.6μm to 0.2μm, which could solve the puzzles encountered in internal magnetic abrasive particles surface finishing on magnetic inductive work piece and had good promising application value.

Abstract: At present, crankshafts are finished mostly by abrasive cloth and manual steel brush, which is not ideal on finishing quality, efficiency and cost, especially cleanness degree does not meet design and use request. So horizontal spindle barrel finishing has been developed. Based on its finishing theory, process characteristics are key factors affecting the finishing effect, especially finishing uniformity. Process characteristics of motion parameters, finishing depth, finishing time, etc. are analyzed, and reasonable parameters are defined. It provides basis for industry application of this process.

Abstract: Magnetic abrasive finishing (MAF) is a processing technology using magnetic abrasive grain (MAG) under magnetic field to finish surface of workpiece. The magnetic fields used in MAF include permanent magnetic field and electromagnetic field. Two conditions must be taken into consideration in the finishing surface of workpiece. One is the sufficient cutting force; the other is the relative moving speed between MAG and workpiece. The principle of step-motor rotating magnetic field is used to produce rotating magnetic field (RMF) in this paper. RMF brings MAG to rotate and keeps workpiece immovable. Meanwhile, the coins vibrate within a definite angle range and reciprocate in axial direction so as to process the outer cylindrical surfaces. Yoke iron is made of two halves so that the coins for rotating magnetic field will be keyed to some section of heavy crankshaft, thus realizing cylindrical surface finishing on the heavy crankshaft. MAG are of importance to MAF . Six performance indexes related to MAG are suggested by studying on process parameters.