What are the most important features of deep hole drilling machining?

Hole is the hole depth to hole diameter ratio L/d ≥ 5, is a difficult problem in machining, especially the large depth to diameter ratio of deep hole machining, the difficulty lies in the tool is thin and long, poor rigidity, low strength, easy to cause tool deflection, and heat dissipation is difficult, chip removal is not easy, and often produces the diameter of the diameter of the larger, appearing taper or hole deflection phenomenon, so as to fail to meet the quality requirements.

Deep Hole Drilling The most important feature of deep hole drilling:

Extremely high material removal rate

Drilling deep holes under normal processing conditions are once through, without the need to back off halfway; can obtain excellent hole size accuracy, straightness, surface roughness, and can be processed in a variety of forms of deep holes, such as cross holes, blind holes, slanted holes, etc.; a high degree of consistency of the quality of processing. When drilling deep holes, the entire drilling process has very high requirements for tools, machine tools and related equipment.

Deep hole machining is in a closed or semi-closed state, so you can not directly observe the cutting of the tool. At present, we can only rely on experience, by listening to the sound, look at the cutting, observe the machine load and pressure gauge, touch the vibration and other appearance phenomena to determine whether the cutting process is normal.

Cutting heat is not easy to spread

General cutting process 80% of the cutting heat is taken away by the chip, and deep hole drilling only 40%, the tool accounted for a larger proportion of the cutting heat, diffusion of late, easy to overheat, the kerf temperature up to 600 degrees, CNC deep hole drilling must be taken to force the effective cooling method.

Chips are not easy to discharge

Due to the depth of the hole, cutting through the route is long, easy to clog, resulting in the collapse of the drill. Therefore, the length and shape of chips should be controlled, and mandatory chip removal.

Poor rigidity of CNC deep hole drilling process system

Due to the limitations of the hole size, the hole length and diameter is relatively large, the drill rod is thin and long, poor rigidity, easy to produce vibration, drilling is easy to go off, and thus the support guide is extremely important. This point is more prominent in the gun drilling machine tools.