Study on influence of layout of DTH bits junk slot on hole-bottom flow field;

In the design theories research of the PDC drilling bit, it systematically study the adaptability between the crest shape of bit and geologic strata, the breaking rock function, arranging design, bit nozzle runner, and junk slot of the cutting gear.

Based on the analysis of tapping force system and characteristic of chip removal, it is confirmed that radial force, axial force and jam of chip removal are the main reasons for poor thread quality.

The main factors that affect deep drilling in NC machine are introduced, such as chip removal, tool cooling and angular axis.

Effects of geometrical parameters of chip-breaker on the carbide cutte r in chip-breaking process are expounded, and the chip-breaking mechanism is a na lyzed.

The relationship between chip-hold groove parameter of shaping miller with shoveling gear and shoveling movement is expounded.

The paper discusses involved problems such as how to select the deviation and tolerance of the major cutting edge length,how to plan grinding of a new broach,regrinding of a used broach ard removing of the chip separation trough,how to use the appropriate cutting lubricant etc.

FEM Analysis on the Simulation of the Metal Cutting Process and Its Application in the Research of Chip Breakers;