Deep hole drill is a kind of machine tool for deep hole processing, which has the characteristics of rapid, accurate and stable deep hole processing. Deep hole drill is a drill specially used for processing deep holes. In machining, holes whose depth to diameter ratio is greater than 6 are usually called deep holes. When drilling deep holes, it is difficult to dissipate heat and chip, and because the drill pipe is thin and long with poor rigidity, it is prone to twists and oscillations. The cooling and chip removal questions are usually handled by means of a pressure cooling system.

Planning criteria for deep hole drilling:

1. Selection criteria for cutter tooth data The cutter tooth data shall be selected according to the load and cutting conditions of each tooth. The base gear is subject to large axial force, severe kneading conflict and poor cutting conditions, so YG or YW cemented carbide inserts with high bending strength and good impact resistance should be considered; Because of the high cutting speed, the outer gear and center gear should be made of YT alloy with good red hardness and high wear resistance, and the guide block should be made of YT material with high wear resistance.

2. Selection criteria of tool view point the view point of deep hole machining tool is primarily determined according to the workpiece data. A reasonable tool perspective is helpful to ensure the stability of the drilling process, chip breaking and improve tool durability.

3. Selection criteria of cutter tooth standard The cutter tooth standard is mainly selected according to the cutting load received by each cutter tooth during the cutting process, and the cutting load is related to the cutter tooth width. The cutter tooth width should be distributed according to the cutting condition of each cutter tooth and the size of the drill bit diameter. The width distribution of cutter teeth shall meet three conditions: a. Ensure that the eccentricity of drill point e=(0.1~0.2) d0. The value of e is related to the data to be processed and the diameter of the drill bit, and its size determines the size and direction of the radial resultant force of the drill bit. The reasonable eccentricity makes the moderate radial force press against the machined hole wall, which can safely drill, strengthen the guidance and improve the hole surface quality. At the same time, the zero cutting of the drill point is avoided, and the bad cutting conditions at the drill center are improved; b. A+C+e+F ＞ d0/2+(1~2) mm, that is, there must be a certain amount of overlap between cutter teeth; c. A+C-e-F ＞ (1~3) mm, which can make the cutting radial force press the guide block all the time, and the guide block pushes forward close to the wall of the machined hole, making full use of the guide effect of the guide block to ensure the straightness of the drilling.