Designing operations for deep hole drilling of small diameters with an internal chip removal tool

2020 ◽  
pp. 12-23
Author(s):  
Yuri I. Kizhnyaev ◽  
Boris Anatol’evich Nemtsev ◽  
Pavel Dmitrievich Yakovlev ◽  
Sergey Pavlovich Yakovlev
Author(s):  
Ce Han ◽  
Ming Luo ◽  
Dinghua Zhang ◽  
Baohai Wu

Due to the enclosed chip evacuation space in deep hole drilling process, chips are accumulated in drill flutes as drilling depth increases, resulting in the increase of drilling torque and lead to drill breakage. Peck drilling is a widely used method to periodically alleviate the drilling torque caused by chip evacuation; the drilling depth in each step directly determines both drill life and machining efficiency. The existing drilling depth optimization methods face problems including low accuracy of the prediction model, the hysteresis of signal diagnosis, and onerous experiments. To overcome these problems, a novel drilling depth optimization method for peck drilling based on the iterative learning optimization is proposed. First, the chip evacuation torque coefficients (CETCs) are introduced into the chip evacuation torque model to simplify the model for learning. Then, the effect of chip removal process in peck drilling on drilling depth is analyzed. The extended depth coefficient by chip removal (EDCbCR) is introduced to develop the relationship between the extended depth in each drilling step and drilling depth. On the foundation of the modeling above, an iterative learning method for drilling depth optimization in peck drilling is developed, in which a modified Newton's method is proposed to maximize machining efficiency and avoid drill breakage. In experiments with different cutting parameters, the effectiveness of the proposed method is validated by comparing the optimized and measured results. The results show that the presented learning method is able to obtain the maximum drilling depth accurately with the error less than 10%.


2010 ◽  
Vol 455 ◽  
pp. 98-102 ◽  
Author(s):  
H.B. Zhao ◽  
Y.F. Nan

The near-dry deep hole drilling system was taken as object in this study,and the contrast experiment between the deep hole drilling system and the traditional(wet)deep-hole drilling system,including the cutting force,the tool wear,the surface quality and the chip-break have been done. The results show that the near-dry system drill stability and have better effort in cooling,lubrication,chip removal effective. The tool life and surface quality within the hole are better,at the same time,it can greatly reducing the amount of cutting fluid,the costs and the pollution of the environment. So we can get a conclusion that it is an ideal system in green drilling process.


Author(s):  
C L Hwang ◽  
C W Hsu

In this paper, a thin and deep hole drilling (TDHD), which is one of the difficult operations in metalworking, is accomplished by a fuzzy discrete sliding mode control (FDSMC) which is a combination of the fuzzy control and the discrete sliding mode control. The kernel problems of TDHD are chip removal, heat buildup, drill life, drill vibration, hole finish, drill breakage, difficulties in modelling the dynamic system, and so forth. The advantageous features of the FDSMC are that it does not require a mathematical model and that it has the invariant properties to resolve uncertainties when the system state is on the sliding surface. Moreover, a woodpeckering strategy can help prevent chip congestion and drill breakage. Finally, the experimental results for a thin and deep hole drilling by the proposed fuzzy discrete sliding mode control using a woodpeckering strategy are presented to verify the usefulness of the system.


2019 ◽  
Vol 88 (6) ◽  
pp. 485-488
Author(s):  
Shinji KAWAI ◽  
Takuya NAGAI ◽  
Shigetaka OKANO

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder

AbstractThe 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 thermomechanical 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 thermomechanical 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.


2021 ◽  
Author(s):  
Anis Farhan Kamaruzaman ◽  
Azlan Mohd Zain ◽  
Noordin Mohd Yusof ◽  
Farhad Nadjarian ◽  
Rozita Abdul Jalil

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