scholarly journals On the influence of thermal processes on the dynamics of a drill during deep hole machining

2019 ◽  
Vol 298 ◽  
pp. 00008
Author(s):  
Leonid Kondratenko ◽  
Lubov Mironova
Keyword(s):  
Heat Source ◽  
Dimensional Accuracy ◽  
Thermal Processes ◽  
Drilling Process ◽  
Drill Bit ◽  
Dynamic Features ◽  
Deep Drilling ◽  
Gun Drill ◽  
Heat Sinking ◽  
Hole Machining

Deep drilling process has been studied and dynamic features of interaction the cutting part of the gun drill with the detail have been identified. Thermal processes of cutting and heat sinking in the interacting chains were analyzed: “heat source – workpiece”; “heat source - chips”; heat source – tool”; “heat source – cooling liquid”. It has been noted that the vibrations lead to the loss of dimensional accuracy of the part fabrication as well as hole surface quality. Mathematical dependence of the longitudinal and torsional oscillations of the cutting drill bit is determined and the influence of heat flow pulsations on the friction coefficients and cutting force is revealed.

Vibration Drilling the 0Cr18Ni9Ti Stainless Steel Micro-Hole

2012 ◽  
Vol 217-219 ◽  
pp. 1592-1595 ◽  
Author(s):  
Peng Zhang ◽  
Chang Hong Mei ◽  
Xing Yu Guo
Keyword(s):  
Stainless Steel ◽  
Hole Drilling ◽  
Drilling Process ◽  
Drill Bit ◽  
Drilling Force ◽  
Process Mechanism ◽  
Micro Hole ◽  
Vibration Drilling ◽  
Hole Machining

Austenite 0Cr18Ni9Ti stainless steel is one of difficult-to-cut materials. It has poor dilling process, especially for micro-hole machining. The main reasons are the tiny drill, poor rigidity, easy to deviation. Moreover, the chip is difficult to discharge, so the drilling force is increased and the drill bit is easy to break, or even it is impossible for micro-hole drilling. In this paper, the vibration drilling process is adopted. The vibration drilling 0Cr18Ni9Ti stainless steel micro-hole process mechanism is researched. The stainless steel micro-hole drilling experiments are conducted. The results show that the vibration drilling can be a better solution for 0Cr18Ni9Ti stainless steel micro-hole processing.

Research on Vibration Drilling 1Cr18Ni9Ti Stainless Steel Micro-Hole

2012 ◽  
Vol 591-593 ◽  
pp. 423-427
Author(s):  
Peng Zhang ◽  
Yan Jing ◽  
Xing Yu Guo
Keyword(s):  
Stainless Steel ◽  
Hole Drilling ◽  
Drilling Process ◽  
Drill Bit ◽  
Drilling Force ◽  
Process Mechanism ◽  
Micro Hole ◽  
Vibration Drilling ◽  
Hole Machining

The austenite 1Cr18Ni9Ti stainless steel is one of difficult-to-cut materials. It has poor dilling process, especially for micro-hole machining. The main reasons are the tiny drill, poor rigidity, easy to deviation. Moreover, the chip is difficult to discharge, so the drilling force is increased and the drill bit is easy to break, or even it is impossible for micro-hole drilling. In this paper, the vibration drilling process is adopted. The vibration drilling 1Cr18Ni9Ti stainless steel micro-hole process mechanism is researched. The stainless steel micro-hole drilling experiments are conducted. The results show that the vibration drilling can be a better solution for 1Cr18Ni9Ti stainless steel micro-hole processing.

Study of Double-Edged Gun Drills with Different Edge Types in Drilling Compacted Graphite Iron

2020 ◽  
Vol 866 ◽  
pp. 22-31
Author(s):  
W.L. Ge ◽  
L. Chen ◽  
X.R. Shi ◽  
Yong Guo Wang
Keyword(s):  
High Efficiency ◽  
Dimensional Accuracy ◽  
Hole Drilling ◽  
Compacted Graphite Iron ◽  
Deep Hole ◽  
Edge Type ◽  
Compacted Graphite ◽  
Gun Drill ◽  
Hole Machining ◽  
Spindle Power

Deep-hole machining is an important part in the field of mechanical processing of diesel engine. Gun drill has been widely used in deep-hole machining because of its high dimensional accuracy, high efficiency and good straightness. Through experiments on drilling compacted graphite iron with two different edge types of double-edged gun drills, the spindle power, axial force and tool wear were analyzed and found out one edge type which is more suitable for processing compacted graphite iron. This paper presents a simulation of deep hole drilling to validate the analysis. The research results have important guiding significance for deep hole processing of compacted graphite iron.

Machinability study and optimization of CNC drilling process parameters for HSLA steel with coated and uncoated drill bit

2021 ◽  
Author(s):  
Nitin P. Sherje ◽  
Sameer A. Agrawal ◽  
Ashish M. Umbarkar ◽  
Prashant P. Kharche ◽  
Dharmesh Dhabliya
Keyword(s):  
Process Parameters ◽  
Hsla Steel ◽  
Drilling Process ◽  
Drill Bit

Study of stick–slip suppression and robustness to parametric uncertainty in drill strings containing torsional vibration tool using sliding-mode control

2021 ◽  
pp. 146441932110452
Author(s):  
Jialin Tian ◽  
Jie Wang ◽  
Siqi Zhou ◽  
Yinglin Yang ◽  
Liming Dai
Keyword(s):  
Torsional Vibration ◽  
Complex Dynamics ◽  
Sliding Mode ◽  
Parametric Uncertainty ◽  
Drill String ◽  
Lumped Parameter Model ◽  
Drilling Process ◽  
Drill Bit ◽  
Stick Slip ◽  
Drilling Operations

Excessive stick–slip vibration of drill strings can cause inefficiency and unsafety of drilling operations. To suppress the stick–slip vibration that occurred during the downhole drilling process, a drill string torsional vibration system considering the torsional vibration tool has been proposed on the basis of the 4-degree of freedom lumped-parameter model. In the design of the model, the tool is approximated by a simple torsional pendulum that brings impact torque to the drill bit. Furthermore, two sliding mode controllers, U1 and U2, are used to suppress stick–slip vibrations while enabling the drill bit to track the desired angular velocity. Aiming at parameter uncertainty and system instability in the drilling operations, a parameter adaptation law is added to the sliding mode controller U2. Finally, the suppression effects of stick–slip and robustness of parametric uncertainty about the two proposed controllers are demonstrated and compared by simulation and field test results. This paper provides a reference for the suppression of stick–slip vibration and the further study of the complex dynamics of the drill string.

Novel Drill Bit Analysis to Delay and Mitigate Fixed Cutter Thermal Damage

2021 ◽  
Author(s):  
Sion Llywelyn Roberts ◽  
Michael James Bailey ◽  
Afshin Babaie Aghdam ◽  
Ahmed Suleiman ◽  
Ahmed Fathy
Keyword(s):  
Cooling Rate ◽  
Design Process ◽  
Thermal Damage ◽  
Drilling Process ◽  
Drill Bit ◽  
Operational Parameters ◽  
Thermal Index ◽  
Testing Phase ◽  
Index Analysis ◽  
Input Load

Abstract As oil and gas wells become deeper, drilling longer intervals is becoming a major milestone for drill bit companies, as the process comes with a variety of challenges affecting the durability of drill bits. Among the major challenges are thermal and impact damage in polycrystalline diamond compact (PDC) cutters, which can significantly affect the performance and longevity of a drill bit. While cutter technology development remains an important arena to address said challenges, there exists a need to also address these through the design process. This paper presents the development and deployment of a new drill bit analysis method that addresses thermal damage by optimizing the design, which has been field validated across the globe. The analysis involves estimating the thermal input load and the available cooling rate for every cutter on a drill bit during drilling conditions. The data is then used to optimize and apply changes to the design. The analysis considers all the critical and relevant operational parameters to calculate these indices. The outcome of the so-called thermal index analysis enables the design team to make informed decisions to improve the design of the drill bit and to minimize the extent of thermal damage in cutters. The improvements made in the design include changes in cutting structure to affect cutting forces and, eventually, the thermal input load during the drilling process. This stage in practice can bring down the temperature of the cutting edge by 20%, as calculated analytically. Another major change that can affect the results is hydraulic design of the bit, which includes the location of the nozzles as well as their orientation and size. In test cases, the cooling rate improved by 50% while keeping the same flow rate though the bit. Several field trials have validated the correlation of thermal index analysis to drill bit dulls. This analysis is now in the field evaluation and testing phase, where it is being used during the design process to improve bits with thermal damage. The field-testing phase has been primarily conducted in thermally challenging applications across the Middle East, North Africa region, and in West Texas.

scholarly journals Optimization of Drilling Process Parameters Via Taguchi, TOPSIS and RSA Techniques

2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Research Work ◽  
Cutting Speed ◽  
High Strength ◽  
Drilling Process ◽  
Drill Bit ◽  
Influence Of Process Parameters ◽  
Light Trucks ◽  
Cfrp Composite

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.

Multiple Rock Breakdown in Electrodischarge Technology

2016 ◽  
Vol 712 ◽  
pp. 55-59
Author(s):  
Vladislav M. Vazhov ◽  
Sergey Y. Datskevitch ◽  
Mikhail Y. Zhurkov ◽  
Vasily M. Muratov ◽  
Arild Rødland
Keyword(s):  
Electric Discharge ◽  
High Voltage ◽  
Voltage Pulse ◽  
Rock Fracture ◽  
High Voltage Pulse ◽  
Electric Strength ◽  
Drilling Process ◽  
Drill Bit ◽  
Research Outcomes ◽  
Experimental Technology

The article covers the research of the electric strength and fracture of rocks that are undergone multiple breakdowns generated by electric discharge rock fracture and drilling technologies. The research outcomes allow proposing an experimental technology able to determine operating high voltage pulse values in the electric discharge drilling process where one should take into account such factors as the rock re-crushing and the drill bit shift cyclicity.

Time and Frequency Domain Investigation of the Static and Dynamic Characteristics of Micro-Drilling

Manufacturing ◽  
2003 ◽  
Author(s):  
Anping Guo ◽  
Steve Batzer ◽  
John Roth
Keyword(s):  
Tool Wear ◽  
Dynamic Characteristics ◽  
Time History ◽  
Drilling Process ◽  
Dynamic Features ◽  
Proper Order ◽  
Micro Drilling ◽  
On Line ◽  
Wear Monitoring ◽  
Dynamic Time

In this paper, the dynamic characteristics of micro-drilling process under different cutting conditions and the resulting correlation to tool wear have been studied. Two types of drills, three spindle speeds and two kinds of workpiece materials were used. In-process cutting forces and accelerations were measured. The signals were analyzed in both the time and frequency domains. Some interesting phenomena were observed in the dynamic time-history response during drilling. Progressive functions with the proper order were obtained to describe the curve of the average thrust force with the number of the holes drilled. Dynamic features which were sensitive to tool wear were found. The changing trends of these dynamic features as the drill wear progresses show a feasibility to develop an on-line drill wear monitoring system by evaluating the changes in dynamic features.

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