coolant in cnc machining

COOLANT IN CNC MACHINING

CNC manufacturing is evolving into the modern multi-process and multi-axis machining operation. A large amount of heat is liberated in CNC machining operation due to friction developed at the tool-work interface. To reduce friction at the cutting zone and to improve the cutting performance, a coolant-fed tooling system is used. The coolant-fed tooling system greatly reduces the friction and temperature which improves the surface finish.

The cutting fluid cools and lubricates the work-tool interface in CNC machining process. It employs computerized controls for coolant supply and the right coolant system will improve the tool life, surface finish and accuracy.

For types of coolant and properties of coolant, refer Chapter 1.35 on Page 1.90.

The cutting fluid performs cooling and lubrication for metal cutting operations. Most of the coolants are made from petroleum distillates, animal fats, plant oils and water. The high- pressure coolant pumping system is used to supply the coolant at high pissure and speed without damage to the machine tool, workpiece and tooling. The high-pressure cooling process overtakes the conventional flood cooling system.

Advantages of coolant in CNC machining:

1. Increased life of the tool

2. Good quality of machined surface

3. Better evacuation of the chip generated

4. Very smooth flow of the coolant

5. Most economical way of coolant-fed tooling system

6. less tool maintenance costs

7. Any type of coolant can be effectively used

8. Completely self-contained unit

9. An automatically detection of overloading and protection and

10. Dirty filter alarm arrangement facility.

1. Rotary coolant feeders:

The supply of the high-pressure coolant through the tooltip during the end milling operation. The high-pressure coolant supplied to a tool cutting point can effectively remove the chips.

2. End mill with coolant holes:

Applying of high-pressure coolant through holes in tool cools the cutting zone and helps chip evacuation. The cutting process with the provision of coolant holes in tools will avoid the welding of chips onto tool surfaces. In standard milling, the life of the cutting tool is increased with the arrangement of coolant holes in the form of spiral shapes. Due to demand from Industries, there is a variety of face milling tools with multiple coolant holes for different applications. It is an efficient tooling method than external coolant flow tooling and increases the tool life and performance in different milling applications. A special coating for the tool surface reduces the cutting resistance and also increases the discharge of chips. It provides a good resistance against heat and oxidation which allows low frictional coefficient and low wear of the tool.

Advantages of coolant-fed tooling:

1. Improved surface finish

2. Prolonged insert life

3. Dynamically balanced holders

4. Dramatically improved chip evacuation and

5. Heavy-duty driving keys for transfer of high torque.

3. Through-Spindle Coolant (TSC) system:

Through-Spindle Coolant (TSC) system is another method of cooling which is an alternate method to flood coolant system. The coolant flows through the tool and discharges at the cutting edge with high pressure in making easy removal of chips. The coolant from the rotating union flows into the spindle axially and makes a better control on tool temperature rise. It provides low machining costs through control over the overheating of a tool along with higher productivity rates. A union is used for delivering the coolant into the spindle. The special features of the coolant feeding system are ideal for indexable drills and solid carbide drills, increased surface finish and reduced tool failure risk due to chip blockage.