Transfer from China Machinery Community
The so-called deep hole processing, is the hole length and the hole diameter ratio is greater than 5. In deep hole processing, the ratio of depth to diameter L / D ≥100. Such as oil cylinder hole, axial oil hole of the shaft, hollow spindle hole and hydraulic valve hole and so on. Some of these holes require higher machining accuracy and surface quality, and some of the processed materials are poor machining, often become a major problem in production.
Deep hole processing plays a very important role in the field of mechanical processing, accounting for about 40% of the hole processing volume. With the progress of science and technology, new types of deep-hole parts with high strength, high hardness and high value appear continuously, and the requirements of machining depth, machining precision and machining efficiency of the workpiece are constantly improved, it makes deep hole machining become the key process and difficult point of machining.
Chip removal in deep hole machining
The key to solve the problem of deep hole processing is chip removal, but in addition to the big problem of chip removal, there are other difficulties, such as can not directly observe the cutting situation, only by sound, chip, machine load, oil pressure and other parameters to judge chip and bit wear; chip heat is not easy to come out; because of drill rod length, poor rigidity, easy vibration, will lead to hole axis deviation, affecting price accuracy and production efficiency.
Process Characteristics of Deep Hole Processing
1.the tool rod is limited by the aperture, the diameter is small and the length is large, resulting in poor rigidity and low strength, and it is easy to produce vibration, ripple and taper when cutting, which affects the straightness and surface roughness of the deep hole.
2.When drilling and reaming, it is difficult to input the cooling lubricant into the cutting zone without special equipment, which reduces the tool durability, and it is also difficult to remove chip.
3.in the deep hole processing process, can not directly observe the cutting situation of cutting tools, can only rely on working experience to listen to the sound of cutting, see chip, hand-touch vibration and workpiece temperature, watch meter (oil pressure meter and meter), to judge whether the cutting process is normal.
4.chip removal is difficult, it is necessary to use reliable means to break chip and control the length and shape of chip, so as to facilitate the smooth removal and prevent chip clogging.
5.In order to ensure the smooth progress of the deep hole in the machining process and achieve the required machining quality, the chip removal device inside (or outside) of the tool, the tool guide and support device and the high pressure cooling lubrication device should be added.
6.The tool heat dissipation condition is bad, the cutting temperature is increased, the tool durability is reduced.
In deep hole machining operation, attention should be paid to the coaxiality of spindle and tool guide sleeve, tool rod support sleeve, workpiece support sleeve and other center lines should meet the requirements; the cutting fluid system should be unblocked and normal; there should be no center hole on the machining end face of the workpiece, and avoid drilling holes on the inclined plane and so on.