Cutting Characteristics of Force Controllable Milling Head

In order to control cutting force and its direction i n milling operation, a new milling head was developed. The head has two milling cutters, which are connected by a pair of gears and rotate in opposite direction respectively. Both up-cut and down-cut can be carried out simultaneously by t hese milling cutters. The each depth of cut, the ratio of up/down cutting depth , by these cutters can be also selected. The cutting force characteristics were experimentally discussed by changing the ratio. The cutting force and its locus can be also changed by the selection of the ratio of up/down cutting depth. For practical usage of the head the analytical prediction method of the cutting forc e characteristics under selected cutting condition was proposed based on the ene rgy approach method proposed, in which both of cutting force characteristics of a single milling cutter and the combined milling cutter under a selected up/dow n cutting depth ratio were analytically estimated based on the two dimensional c utting data. It was experimentally shown that in NC milling machine the cutting force locus was controlled in pre-determined direction under various tool paths .

CUTTING REGULARITY AND DISCHARGE CHARACTERISTICS BY USING COMPOSITE COOLING LIQUID IN WIRE CUT ELECTRICAL DISCHARGE MACHINE WITH HIGH WIRE TRAVELING SPEED

The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid＇s washing ability. Discharge characteristics and theoretic analysis between two electrodes are also discussed based on discharge waveform. By using composite cooling liquid which has strong washing ability, the efficiency in the first stable cutting phase has reached more than 200 mm^2/min, and the roughness of the surface has reached Ra〈0.8 μm after the fourth cutting with more than 50 mm^2/min average cutting efficiency. It is pointed out that cutting situation of the wire cut electrical discharge machine with high wire traveling speed （HSWEDM） is better than the wire cut electrical discharge machine with low wire traveling speed （LSWEDM） in the condition of improving the cooling liquid washing ability. The machining indices of HSWEDM will be increased remarkably by using the composite cooling liquid.

Recent Advances in Drilling Tool Temperature:A State‑of‑the‑Art Review

Drilling is regarded as the most complex manufacturing process compared with other conventional machining processes.During the drilling process,most of the energy consumed in metal cutting is converted to heat and increases temperature considerably.The resulting thermal phenomena are important since they influence the mode of deformation,the final metallurgical state of the machined surface,and the rate of tool wear.Hence,understanding the temperature characteristics in the drilling process is crucial for enhancing the drill performance and process efficiency.Extensive efforts have been conducted to measure and control the drilling tool temperature successively.However,very few studies have been conducted from a comprehensive perspective to review all the efforts.To address this gap in the literature,a rigorous review concerning the state-of-the-art results and advances in drilling tool temperature is presented in this paper by referring to the wide comparisons among literature analyses.The multiple aspects of drilling tool temperature are precisely detailed and discussed in terms of theoretical analysis and thermal modeling,methods for temperature measuring,the effect of cutting parameters,tool geometries and hole-making methods on temperature and temperature controlling by different cooling methods.In conclusion,several possible future research directions are discussed to offer potential insights for the drilling community and future researchers.