It is difficult to dissipate heat and remove chips during deep hole drilling, and the manufacturer of internal chip removal deep hole drill is prone to bending and vibration due to the slender and poor rigidity of the drill pipe. Generally, the pressure cooling system is used to solve the problems of cooling and chip removal. The manufacturer of internal chip removal deep hole drill sells directly

1. Workpiece thermal deformation: when the temperature of the blank starts to rise after rough cutting, the uneven cooling of the front and back of the hole causes the size of the hole to exceed the tolerance, resulting in taper;

2. Insufficient rigidity: the rigidity of drill pipe is insufficient due to the long extension of ram and drill pipe, as well as the installation of pipe for processing, and there are bouncing lines during drilling, resulting in out of tolerance accuracy of the hole;

3. Insufficient compensation: when the ram of the drilling machine extends, the ram is kept horizontal and clamped by oil pressure compensation. When the oil pressure compensation is insufficient, the deep hole drilling with internal chip removal will cause the verticality of the hole to be out of tolerance if the drill pipe and ram have a slight deviation under the action of the cutting force;

4. The surface roughness is out of tolerance: the actual size of the hole after fine drilling has errors, which are small in the front and large in the rear. If the tool wear is the cause, the hole should be large in the front and small in the rear, which means that the drill pipe swings greatly after extending out of the drill pipe, resulting in the taper of the hole after fine drilling.