Influence of the coolant nozzle orientation and size on the tool temperature under high-pressure coolant supply using an analogy test bench

Abstract

In many examinations, high-pressure coolant supply showed its’ great potential to improve the productivity when machining difficult to cut materials. However, most examinations regarding the supply of metalworking fluid at elevated pressure were performed in turning. Accordingly, a profound knowledge of the fundamental mechanisms of the focused high-pressure coolant supply in milling is vital for an optimal process and tool design and mostly still missing. However, especially the sensor-based examination of the cooling effect on the tool temperature in milling under coolant supply is highly challenging, because the rotation of the tool prevents the direct application of temperature sensors in the tool. Therefore, an analogy test bench for lathes was developed to generate an interrupted cut and chips with a non-constant undeformed chip thickness h. With this test bench, different coolant supply strategies with different coolant nozzle orientation, coolant supply pressure and volumetric flow rate were examined. The results show, that the coolant supply pressure, volumetric flow rate and coolant nozzle orientation have a major influence on the tool temperature. As opposed to this, no major influence was found on the cutting force.