The Analysis And Optimization Of Ram Of Large Floor Boring And Milling Machine

Industry as a measure of a country’s standard, which has become increasinglyimportant in modern society, and equipment is an important part of modern industry. Nowthe development of CNC machine tools is far behind abroad in some respects oftechnology, how to improve the precision and reliability of machining is an issue that everytechnology researcher have to face. Ram is a very important part of large machine in thisstudy, the straightness of operation and the characteristics of static and dynamic will affectthe processing performance parts directly.In this paper, the characteristics of hydrostatic guideway were introduced. With thecombination of the headstock-ram structural characteristics, the distribution of oil pad weredetermined. By the weight of ram and related parameters, the oil pad size and distributionof initial pressure were gotten, then the relationship between the offset of the ram and theoil chamber capacity, stiffness, the rate of flow was calculated, and obtain the curvilinearrelationship, Finally the conclusion was that the ram of the offset less than0.2, it satisfiedthe demands of designing, and also ensured the straightness.With Solidworks modeling ram, and through empirical formulas, the boring andmilling force under different conditions were gotten. During the static analysis, consideringthe influence of the spindle and its attachments, for the different speed and cutterheaddiameter, with the analysis of ANSYS Workbench, the ram deformation values were gotten.During the dynamic analysis of ram, analogging film stiffness into spring, then the sixmodal were gotten. With transient analysis, the graph of the stress of cutting forces andram deformation in three directions over time were obtained. Its maximum stress value issmall, the design was conservative, so the ram had the space of optimization.Before optimizing the ram, the paper conducted the topology optimization firstly, alsoidentifing the regions of material which can be removed. By changing the ribs and thethickness of outer wall, the relationship of strain and weight were gotten, and finally thebest optimization program were determined, by adjusting the position of the ribs, the thickness changed from30mm to27mm, wall thickness changed from30mm26mm, themodified ram weight was1935.3kg, loss5.8%. And the ram still maintained a greatstiffness and strength, fully met the processing requirements.