Whirling vibration of drilling shaft in minimal quantity lubrication deep hole drilling using theoretical and experimental investigation

2014 ◽  
Vol 229 (13) ◽  
pp. 2433-2442
Author(s):  
Lingfei Kong ◽  
Han Niu ◽  
Xiaoli Hou ◽  
Qingfeng Wang
Keyword(s):  
Surface Roughness ◽  
Rotational Speed ◽  
Cutting Fluid ◽  
Hole Drilling ◽  
Experimental Investigations ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Minimal Quantity Lubrication ◽  
Minimal Quantity

Under the concept of safety, improving efficiency, or reducing costs in deep hole drilling, the effect of minimal quantity lubrication (MQL) on the dynamic characteristics of drilling shaft is analyzed. A model is presented to describe the pressure function of MQL cutting fluid during drilling process. This model is based on the compressible Reynolds equation in air/oil feature with nonlinearity, and the differential transformation theory is introduced to solve the time-dependent pressure equation satisfied with MQL cutting fluid. Further, with an emphasis on model development, experiments are performed to validate the correctness and effectiveness of the above methods. A series of experimental investigations are carried out on the whirling characteristics of drilling shaft when the rotational speed and drilling depth are changed. Additionally, the vibration trajectories of drilling shaft and the surface roughness of hole are detected under different experimental conditions such as MQL drilling or traditional drilling. The results show that the whirling trajectory of drilling shaft decreases significantly in MQL deep hole drilling but the surface roughness of machined hole is worse due to surface scratches or scales. Nevertheless, there exists an optimal rotational speed of drilling shaft to improve machining precision of hole surface. These results indicate that the MQL method has shown potential to be even more productive as compared to traditional drilling and that the proposed method in this paper can lay a foundation for investigating the dynamic stability of drilling shaft in MQL drilling.

Experimental Investigation of Bubble-Mixed Cutting Fluid Delivery for Micro Deep-Hole Drilling

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Chi-Ting Lee ◽  
Soham S. Mujumdar ◽  
Shiv G. Kapoor
Keyword(s):  
High Performance ◽  
Cutting Fluid ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Delivery Method ◽  
Dry Cutting ◽  
Deep Hole Drilling ◽  
Fluid Delivery ◽  
Drilling Performance

In drilling, chip-clogging results in increased drilling temperature, excessive tool wear, and poor hole quality. Especially, in microdrilling, low rigidity of the tool and inability of cutting fluid to penetrate narrower tool–workpiece interface significantly reduce the drilling performance. A novel bubble-mixed cutting fluid delivery method proposed in this research aims toward achieving a high-performance micro deep-hole drilling process with a significant reduction in the consumption of cutting fluid. Experimental results show that the bubble-mixed cutting fluid delivery method achieves lower thrust force during drilling, higher drilled depth before tool breakage, and lower dimensional and circularity errors when machining deep holes in comparison with dry cutting or conventional flood delivery method. It is also found that the smaller-sized bubbles effectively penetrate the tool–workpiece interface during the drilling producing deeper holes by better chip evacuation and cooling.

scholarly journals Experimental and simulative investigation of the oil distribution during a deep-hole drilling process and comparing of the RANS kω-SST and RANS hybrid SAS-SST turbulence model

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Ekrem Oezkaya
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Hole Drilling ◽  
Experimental Investigations ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Drilling ◽  
Deep Hole Drilling ◽  
Sst Model ◽  
Cooling And Lubrication

Helical deep hole drilling is a process frequently used in industrial applications to produce bores with a large length to diameter ratio. For better cooling and lubrication, the deep drilling oil is fed directly into the bore hole via two internal cooling channels. Due to the inaccessibility of the cutting area, experimental investigations that provide information on the actual machining and cooling behavior are difficult to carry out. In this paper, the distribution of the deep drilling oil is investigated both experimentally and simulatively and the results are evaluated. For the Computational Fluid Dynamics (CFD) simulation, two different turbulence models, i.e. the RANS k-ω-SST and hybrid SAS-SST model, are used and compared. Thereby, the actual used deep drilling oil is modelled instead of using fluid dynamic parameters of water, as is often the case. With the hybrid SAS-SST model, the flow could be analyzed much better than with the RANS k-ω-SST model and thus the processes that take place during helical deep drilling could be  simulated with realistic details. Both the experimental and the simulative results show that the deep drilling oil movement is almost exclusively generated by the tool rotation. At the tool’s cutting edges and in the flute, the flow velocity drops to zero for the most part, so that no efficient cooling and lubrication could take place there. In addition, cavitation bubbles form and implode, concluding in the assumption that the process heat is not adequately dissipated and the removal of chips is adversely affected, which in turn can affect the service life of the tool and the bore quality. The carried out investigations show that the application of CFD simulation is an important research instrument in machining technology and that there is still great potential in the area of tool and process optimization.

Experimental Research on the System Performance in Near-Dry Deep Hole Drilling

2010 ◽  
Vol 455 ◽  
pp. 98-102 ◽  
Author(s):  
H.B. Zhao ◽  
Y.F. Nan
Keyword(s):  
Surface Quality ◽  
System Performance ◽  
Cutting Fluid ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Ideal System ◽  
Drilling System ◽  
Chip Removal

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.

scholarly journals Temperature monitoring in the subsurface during single lip deep hole drilling

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder
Keyword(s):  
Cutting Parameters ◽  
Drill Hole ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Machining Processes ◽  
Deep Hole Drilling ◽  
Feed Force ◽  
Cutting Zone

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.

scholarly journals Cutting-fluid flow with chip evacuation during deep-hole drilling with twist drills

2021 ◽  
Author(s):  
Andreas Baumann ◽  
Ekrem Oezkaya ◽  
Dirk Schnabel ◽  
Dirk Biermann ◽  
Peter Eberhard
Keyword(s):  
Fluid Flow ◽  
Cutting Fluid ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Twist Drills

scholarly journals Optimization of Surface Roughness in Deep Hole Drilling using Moth-Flame Optimization

2019 ◽  
Vol 18 (3-2) ◽  
pp. 62-68
Author(s):  
Anis Farhan Kamaruzaman ◽  
Azlan Mohd Zain ◽  
Razana Alwee ◽  
Noordin Md Yusof ◽  
Farhad Najarian
Keyword(s):  
Surface Roughness ◽  
Optimization Algorithm ◽  
Feed Rate ◽  
Spindle Speed ◽  
Hole Drilling ◽  
P Value ◽  
Machining Parameters ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Moth Flame Optimization Algorithm

This study emphasizes on optimizing the value of machining parameters that will affect the value of surface roughness for the deep hole drilling process using moth-flame optimization algorithm. All experiments run on the basis of the design of experiment (DoE) which is two level factorial with four center point. Machining parameters involved are spindle speed, feed rate, depth of hole and minimum quantity lubricants (MQL) to obtain the minimum value for surface roughness. Results experiments are needed to go through the next process which is modeling to get objective function which will be inserted into the moth-flame optimization algorithm. The optimization results show that the moth-flame algorithm produced a minimum surface roughness value of 2.41µ compared to the experimental data. The value of machining parameters that lead to minimum value of surface roughness are 900 rpm of spindle speed, 50 mm/min of feed rate, 65 mm of depth of hole and 40 l/hr of MQL. The ANOVA has analysed that spindle speed, feed rate and MQL are significant parameters for surface roughness value with P-value <0.0001, 0.0219 and 0.0008 while depth of hole has P-value of 0.3522 which indicates that the parameter is not significant for surface roughness value. The analysis also shown that the machining parameter that has largest contribution to the surface roughness value is spindle speed with 65.54% while the smallest contribution is from depth of hole with 0.8%. As the conclusion, the application of artificial intelligence is very helpful in the industry for gaining good quality of products.

scholarly journals Improved empirical wavelet denoising algorithm with application to whirling detection in deep hole drilling process

Procedia CIRP ◽  
2021 ◽  
Vol 104 ◽  
pp. 1924-1929
Author(s):  
Yue Si ◽  
Xuyang Li ◽  
Lingfei Kong ◽  
Jianming Zhen ◽  
Yan Li
Keyword(s):  
Wavelet Denoising ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Hole Drilling
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