Temperature monitoring in the subsurface during single lip deep hole drilling

Abstract

The surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermo-mechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermo-mechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

Simulation Study on Single-Lip Deep Hole Drilling Using Design of Experiments

“…The experimental setup is shown schematically in Figure 1a. This setup is part of a more complex experimental framework, which is not part of the present study [10,14,15]. The experimental investigations were performed on the deep hole drilling machine Mö-TM-HF-16-2-S (Walter Möck GmbH, Sonnenbühl, Germany).…”

Investigation of the Effect of Drill Bit Feature on Hole Surface Quality and Tool Wear

“…They stated that the surface roughness increased at the hole exit under all experimental conditions. Wegert et al [8] examined the temperature and wear in the drilling zone. They stated that with a drill bit, the temperature value increased to 150 0 C after three dry drilling operations.…”

Experimental and computational analysis of the coolant distribution considering the viscosity of the cutting fluid during machining with helical deep hole drills

“…Suitable cutting parameters to produce process-favorable short-breaking chips [24] and the precise control of the cooling lubricant [25,26] therefore play an important role to prevent insufficient bore hole quality and excessive tool wear [23,27,28]. In studies by Wegert et al [29], a lack of cooling lubricant supply led to chipping of the cutting edges of single-lip deep hole drills. However, Wegert et al [29] observed an influence of the cooling lubricant supply on the temperature development in the subsurface zone of the bore hole wall.…”

“…In studies by Wegert et al [29], a lack of cooling lubricant supply led to chipping of the cutting edges of single-lip deep hole drills. However, Wegert et al [29] observed an influence of the cooling lubricant supply on the temperature development in the subsurface zone of the bore hole wall. The temperature of the subsurface zone, which is influenced by the cooling lubricant supply, is also the focus of Schmidt's current investigations.…”