In fact, changing lathe to gun drill is a special tool for deep hole machining, so what is the safe use method of changing lathe to gun drill? Let's take a look:
1. When the lathe is used to change the gun drill, the guide sleeve with suitable size must be selected first. The gap between the guide sleeve and the head of the gun drill is kept within 0.003mm-0.008mm. The spindle of the machine tool using the gun drill must have higher axial and radial rigidity, and the guide sleeve and the spindle must have higher coaxiality. In the process of drilling, the drilling position of the processed material (especially the casting) shall be free of fracture, air hole and other impurities, otherwise, it will cause edge collapse or even turn around. The cutting parameters should be selected correctly. Generally, cutting speed: v = 1.1-1.65m/s, feed rate: S = 0.015-0.03mm/r, oil pressure: P = 2.5-6.0mpa, flow rate: q = 0.2-0.65l/s.
2. The cutting fluid used in gun drill is more exquisite, which directly affects the accuracy of the hole being processed. Be sure to select special gun drilling oil. Generally, cutting fluid for gun drilling should have extreme pressure additives to ensure the formation of oil film under high pressure and prevent dry grinding. The viscosity of cutting fluid is related to the drilling diameter. The smaller the diameter is, the lower the viscosity is. Compared with general machining, the cutting oil sent to gun drill cutting area has the characteristics of large pressure, large flow rate and high filtering accuracy.
Finally, it reminds us that the flow rate should increase with the increase of the hole depth, so as to ensure that the cutting oil has a greater flow rate and achieve the purpose of smooth chip removal.