xiehe model

In the case of the same machining accuracy and surface roughness, the machining of the hole is more difficult than the machining of the outer circle, and the productivity is low and the cost is high. This is because the size of the tool is limited by the size of the hole to be machined, so the tool is less rigid and cannot use a large amount of cutting. When machining holes, the cutting area is inside the workpiece, and the cutting fluid is not easy to enter the cutting area, and the chips are removed to dissipate heat.

Hole processing methods include drilling, reaming, reaming, boring, deep drawing, grinding and hole finishing. In addition, the processing method that replaces conventional drilling is drilling deep holes and heating. Drilling, laser drilling, electron beam drilling, EDM drilling, etc. Different parts and materials, different sizes, different precision requirements, choose different tools; different efficiency requirements, different mass production requirements, different straightness ratios, and different processing techniques.

Deep hole processing

Deep hole machining is a type of machining that is dominated by tools designed for existing applications. Deep hole machining involves many different industries. Today, success in this machining area is often based on a mix of standard and specialty tooling components with experience designing specialized deep hole machining tools. These tools feature extended high-precision holders with supports and integrated reamers, combined with the latest cutting edge geometries and insert materials and efficient coolant and chip control for maximum penetration and process safety get the high quality you need.

Difficulty

(1) Cutting conditions cannot be observed directly.

(2) Cutting heat is not easy to transfer.

(3) Chip removal is difficult, if it is blocked by chips, it may damage the drill bit.

(4) Due to the long length of the drill pipe, poor rigidity, and easy vibration, the axis of the hole is easy to deviate, which affects the machining accuracy and production efficiency.

Precautions for deep hole processing

(1) Main points of deep hole machining operation: the coaxiality between the center line of the spindle and the tool guide sleeve, tool holder support sleeve, and workpiece support sleeve should meet the requirements; the cutting fluid system should be unimpeded; the machining end surface of the workpiece should not have a center. Drill holes and avoid drilling on slopes; the chip shape should be kept normal to avoid the formation of straight chips; through-holes are processed at a high speed, and when the drill is about to drill through, the speed should be reduced or stopped to avoid damage to the drill.

(2) Cutting fluid for deep hole processing: A large amount of cutting heat is generated during deep hole processing, which is not easy to spread. Sufficient cutting fluid must be supplied to lubricate the cooling tool. Generally, 1:100 emulsion or extreme pressure emulsion is used; when higher processing accuracy and surface quality are required or tough materials are processed, use for extreme pressure emulsion or high-concentration extreme pressure emulsion, the kinematic viscosity of the cutting oil is usually selected (40°C) 10-20cm2/s, and the flow rate of the cutting fluid is 15-18m/s; Oil; for high-precision deep hole processing, the proportion of cutting oil can be 40% extreme pressure vulcanized oil + 40% kerosene + 20% chlorinated paraffin.

(3) Precautions for using deep hole drill:

A. The end face of the workpiece is perpendicular to the axis of the workpiece to ensure reliable sealing of the end face.

B. Pre-drill a shallow hole in the workpiece hole before formal processing, and guide the centering action when drilling.

C. In order to ensure the service life of the tool, it is best to use automatic walking.

D. After the water inlet guide and movable center support are worn out, they should be replaced in time to avoid affecting the drilling accuracy.