Maximum Depth Of Cut Research Articles

Determining the maximum turning force of the hydraulic backhoe excavator bucket

Introduction. Single-bucket excavators with both flexible and rigid suspension of work equipment are actively engaged in construction, stripping work and production mining. Excavators with rigid suspension are commonly used in construction, while excavators with flexible suspension are used in mining practice. This work considers the process of excavating rock with a single-bucket hydraulic backhoe excavator. The reliability and durability of excavators depend on the correct choice of the parameters of work equipment elements. Research objective is to determine the maximum turning force of the bucket of a hydraulic backhoe excavator, taking into account soil friction against the bucket bottom and side plates during rock excavation. Methods of research. When the maximum force on the bucket turning hydraulic-cylinder rods in the course of rock excavation is analytically defined, it is advisable to consider digging a trench in plain surface or in the open-pit in plain surface of a stope face provided that per one turn the bucket is filled to capacity. In this case, a segment of soil cut from the rock mass has maximum depth of cut as compared to other excavation methods. Total excavation resistance includes: resistance arising from cutting rock with a bucket with maximum depth of cut; resistance associated with the impact of gravity of the rock mass on the bucket; resistance associated with rock mass friction against the bucket bottom; resistance associated with rock mass friction against the inner surfaces of the bucket side plates. Results. The dependence has been determined between the maximum force on the bucket turning hydraulic-cylinder rods and bucket design parameters as well as the physical and mechanical characteristics of the face rock. The results analysis showed that both excavation process flow scheme and rock characteristics have a significant influence on the total bucket excavation resistance. Conclusions. The developed method of calculating the excavation resistance takes into account the internal forces of bucket interaction with rock and makes it possible to increase the accuracy of maximum digging force calculation. It therefore becomes possible to more reasonably approach the choice of the excavator bucket turning hydraulic cylinder parameters and thereby increase the reliability and durability of the machine as a whole.

Least squares modeling of the depth of cut of reservoir rock from real-time drilling parameters

Exploration is the process of a wellbore being drilled below the Earth’s surface, and produced through a production tubing to the wellhead. In drilling modeling, optimization and statistical analysis are important. Optimizing drilling process is a technical strategy to drill wells more productively. This paper aims at least squares modeling and statistical analysis of the depth of cut of reservoir rock from real-time drilling parameters. Real-time drilling data was obtained from drilling process of the reservoir rock in North Brae Sea (offshore) with the coordinate “58.70 N 1.30 E”. Within the data set, “Revolution Per Minute (RPM)” (rev/min), “Rate of penetration (ROP)” (ft/min), are the independent variables, and the “depth of cut”, the response variable. Maximum depth of cut is found to be 1.0533 and achieved at Revolution Per Minute (RPM) and Rate of penetration (ROP) values of 81.4626 and 85.8096, respectively. Least squares method was assessed for fitting the data set and found to provide a decent fit to the drilling data. Statistical analysis reveals that the model is highly significant with R squared value, adjusted R squared value and Predicted R squared values value of 100.00%, 100.00% and 99.99%, respectively. Hence, the linear model developed could be used for predicting the depth of cut of the reservoir rock.

Experimental study on CNC engraving parameters of Afghan white jade

The CNC machining of nephrite is increasingly used in the jade engraving industry. As the most important standard for quality evaluation, surface roughness is influenced by cutting parameters. In this paper, taking the Buddha head as the machining object, the influence of cutting parameters on the surface quality of was studied by SYIL S7 CNC milling machine. The grooving experiment was carried out at spindle speed of 24,000 rpm, then the CAXA manufacturing engineer and JDpiant software were comparatively applied in machining. Furtherly, the influence of the spindle speed on the roughness was investigated. The research results were summarized as follows: (1) No edge breakage appeared when feed speed lower than 300 mm/min with the maximum depth of cut of 0.1 mm. In this case, when the jade is machined with the spindle speed range of 16,000–24,000 rpm, the mean roughness Ra was in the range of 1,496.111–891.842 nm. (2) JDpiant software is more suitable for CNC jade engraving than CAXA manufacturing engineer. (3) In roughing stage, only the high-speed grinding contdition is satisfied, the integrity of side profile could be guaranteed. The higher spindle speed was conducive to achieve the fine surface quality. (4) The tungsten steel cutter in finish machining stage shows better grinding ability than diamond cutter used in rough machining stage. In order to formulate an economic spindle speed, the finishing surface roughness should be considered in conjunction with the requirement of polishing.

Experimental Investigation and Optimization of SiC Abrasive Water Jet Machining of Aluminium Alloys

Investigation of the parameters variation over the abrasive water jet machining of aluminium 2014 alloy was studied using the Taguchi technique. Traverse speed, standoff distance, pressure and mass flow rate were considered as the process parameters and were varied at three levels. The depth of cut was taken as the response, and it was measured and analysed statistically. The optimal parameters to achieve the maximum depth of cut were identified with the main effect plot. Most influencing parameters over the depth of cut were identified with the analysis of variance and response table. A mathematical relationship was developed to predict the depth of cut.

A study on preheating temperature and heat affected depth according to various laser beam angle for laser-assisted machining

Laser-assisted machining (LAM) is a new method and actively researched for various difficult to machine materials. In LAM, machining is carried after prediction of material removal temperature (preheating temperature) for material with fixed cutting depth using a laser source. Among the various difficult-to-cut materials, Inconel 718, nickel-based super alloys, is difficult to machine due high strength at elevated temperature and low thermal conductivity. Studies on machining of Inconel 718 using a laser has been performed for various position of laser source to reveal the process benefits of Inconel 718 with fixed cutting depth. But there are no studies and results on prediction of heat affected depth for preheating temperature using laser assisted machining of Inconel 718 on various laser beam angle. So, in the present study, the effect of application of laser when applied at different angles is studied by two different methods- one with offset and other without offset. Finite element method is used to perform the simulations. This contribution brings a new novelty to the present research work on metal cutting domain using laser. The heat affected depth was also found and compared with depth obtained through experiments. And, the error percentage found for heat affected depth and preheating temperature is about 11%. The experimental results reveal that laser beam at an angle of 60° has maximum depth of cut, while minimum depth of cut is found at 90°.

Energy Demand Simulation of Machine Tools with Improved Chatter Stability Achieved by Active Damping

The electric base load of milling machine tools has a high share of the machine’s total energy consumption. An approach to decrease the energy demand per workpiece is to shorten the machining time by raising the material removal rate. The maximum feed depends on the tool’s wear resistance while the maximum depth of cut is often limited by the chatter stability of the machine. In this paper active damping is used to damp chatter vibrations, which leads to a higher depth of cut. To evaluate the decrease of energy consumption for any workpiece, a modeling methodology for the energy demand of machine tools was developed, which is presented in this paper. The methodology is able to estimate the energy requirements of the spindle during cutting, of the feed drives, of the auxiliary equipment and of the base load. The numerical results were experimentally validated by different 2.5D machining processes, with good agreement between the simulation model and the experimental results. Therefore, the proposed methodology can be used effectively for calculating the total energy required for the machining of any workpiece. In addition, the structural dynamics of the machine tool, the active damping system and the cutting process were modeled in order to simulate the chatter stability. This enables a straightforward determination of the optimum cutting parameters as well as a comparison of different milling part programs, both in terms of the energy demand. Furthermore, it is possible to evaluate the energy conservation by active damping and to point out for which cutting processes active damping is useful.

Numerical Analysis of Laser Preheating for Laser Assisted Micro Milling of Inconel 718

Micro milling of super alloy materials such as nickel based alloys such as Inconel 718 is challenging due to the excellent of its mechanical properties. Therefore, new techniques have been suggested to enhance the machinability of nickel based alloys by pre-heating the workpiece’s surface to reduce its strength and ductility. The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in terms of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm.

Determination of Heat Flux Intensity Distribution and Laser Absorption Rate of AISI D2 Tool Steel

The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in term of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm.

A hybrid electromagnetism-like algorithm for integration of process planning and capacitated lot-sizing problem

The capacitated lot-sizing problem (CLSP) is extensively discussed in the operation management literature. The CLSP concerns balancing set-up costs against inventory costs under a common capacity constraint, and considers a limited time horizon such that total costs can beminimized. In this regard, the integration of process and production planning is essential toimprove system performance. This paper proposes a model for the integration of process planning and production planning for turning parts that can be implemented in CLSP. The developed model simultaneously considers the technology-related constraints and shop floor constraints determined by the available time. In this approach, two new variables are defined for CLSP: part machining time and cost. This model takes the maximum depth of cut and feed rate for each feature with regard to technology constraints, and the spindle speed is selected in CLSP. Since the proposed optimization model is included in the class of NP-hard problems, a hybridization of two meta-heuristic algorithms (an electromagnetism-like algorithm and a simulated annealing algorithm) is used to solve the problem in acceptable time. Finally, the algorithm proposed in this paper is applied on a case study, and the results are discussed.

Improvement in machining performance of die-sinking EDM by using self-adjusting fuzzy control

Recently, in order to increase the autonomy of machines, the knowledge engineering is being applied widely in the field of the electrical machining. The fuzzy control is known well as one of the most effective ways for the knowledge engineering to maintain the stability of the non-deterministic machining such as die-sinking EDM [Int. J. Mach. Tools Manuf. 43 (13) (2003) 1287; J. Mater. Process. Technol. 129 (1–3) (2002) 45; Modern Mach. Shop 70 (7) (1997) 262; IEEE Trans. Automatic Control 35 (2) (1990) 148; Modern Mach. Shop 66 (5) (1993) 130]. Even the fuzzy control is powerful, the ability of the machine would never grow as long as the fuzzy rules are fixed. This investigation was carried out to examine the validities of a self-adjusting fuzzy control on die-sinking EDM. The stability of machining could be calculated properly by using a simplified fuzzy inference with only two input signals such as a frequency of short circuit and a frequency of arcing. And by controlling the jump heights and the approaching movement of the tool electrode according to the calculated stability, a remarkable improvement in machining speed and the maximum depth of cut was achieved.

Improvement in machining performance of die-sinking EDM by using self-adjusting fuzzy control

Recently, in order to increase the autonomy of machines, the knowledge engineering is being applied widely in the field of the electrical machining. The fuzzy control is known well as one of the most effective ways for the knowledge engineering to maintain the stability of the non-deterministic machining such as die-sinking EDM [Int. J. Mach. Tools Manuf. 43 (13) (2003) 1287; J. Mater. Process. Technol. 129 (1–3) (2002) 45; Modern Mach. Shop 70 (7) (1997) 262; IEEE Trans. Automatic Control 35 (2) (1990) 148; Modern Mach. Shop 66 (5) (1993) 130]. Even the fuzzy control is powerful, the ability of the machine would never grow as long as the fuzzy rules are fixed. This investigation was carried out to examine the validities of a self-adjusting fuzzy control on die-sinking EDM. The stability of machining could be calculated properly by using a simplified fuzzy inference with only two input signals such as a frequency of short circuit and a frequency of arcing. And by controlling the jump heights and the approaching movement of the tool electrode according to the calculated stability, a remarkable improvement in machining speed and the maximum depth of cut was achieved.

Finite Element Analysis of Brittle Cracking due to Single Grit Rotating Scratch

Finite element analysis of single grit rotating scratch on brittle materials was conducted using an “elastic-plastic-cracking” (EPC) model. The brittle material removal mechanism was modeled based on a critical crack-opening displacement criterion. It was found that the tangential and normal force profiles as well as the damage morphology observed in scratch experiments were fully captured by the EPC model. The results revealed that the induced damage zone size increases linearly with a brittleness parameter EY/σf21/3 as well as the maximum depth of cut.

Unmanned Turning Force Control Based on the Spindle Drive Characteristics.

While the rough turning process is machining a workpiece at various cutting depth, the feedrate is usually selected based on the maximum depth of cut. Even if this selection can avoid power saturation or tool breakage, it is very conservative compared to the capacity of machine tools and can reduce the productivity significantly. Many adaptive control techniques have been reported that can adjust the feedrate to maintain the constant cutting force. However, these controllers are not very widely used in manufacturing industry because of the limitations in measuring the cutting force signals and selecting the appropriate cutting force level. In this paper, an unmanned turning process control system is proposed based on the spindle drive characteristics. A synthesized cutting force monitor is introduced to estimate the cutting force as accurately as a dynamometer does. The reference cutting force level as well as the feed-rate is selected considering the spindle motor characteristics. Because the cutting process is highly nonlinear, a fuzzy logic controller is applied to maintain the desired cutting force level. The experimental results demonstrate that the proposed system can be easily realized in CNC lathe with requiring little additional hardware.

Ramanmicrospectroscopy analysis of pressure-induced metallization inscratching of silicon

A single-point diamond turning machine was usedto make grooves on (111) p-type single-crystal silicon wafersat room temperature. Scratch tests have been performed withboth sharp (Vickers and conical) diamond tools, and a spherical(Rockwell) diamond tool. Our results showed that materialremoval mechanisms differed between these tools.Pressure-induced metallization of Si allows the ductile regimemechanical micromachining of wafer surfaces. Ramanmicrospectroscopy and electron microscopy were used todetermine the machining parameters that do not introducecracking or other types of damage. The surface of the groove,after machining, was covered by a mixture of metastable,high-pressure silicon phases and amorphous silicon. Further,these phases can be transformed into cubic silicon byannealing. The maximum depth of cut in the ductile regime hasbeen determined for the given scratch test conditions andtools. The developed technique can be used to machine Ge, GaAsand other semiconductors. Applications drawing from thisresearch are many. For example, channels for microfluidicdevices can be engraved with a channel cross-section that isdetermined by the shape of the tool, which allows patterns thatcannot be produced using etching. There are no limitations onthe channel length or direction, and the channel width can varyfrom potentially a few nanometres to several micrometres.

A SIMPLIFIED SOLUTION FOR THE DEPTH OF CUT IN MULTI-PATH BALL END MILLING

The axial depth of cut is an important factor in the dynamic cutting force analysis of milling. In multi-path ball end milling, it varies with the cutting edge position angle. General equations are derived from which the instant depth of cut in ball end milling can be calculated. Examples are given for four path increment modes. The cutting condition in each mode is discussed with respect to the depth of cut. The conditions needed to disengage the tip of the ball end mill from the cut are determined. The "step-up" increment mode has the most favorable cutting condition for cutter tip relief and high cutting velocity. In order to obtain an instant evaluation of the cutting stability, the equations of maximum depth of cut in ball end milling are derived. The exact solutions are obtained from the general equations for the instant depth of cut. More conservative estimates are obtained from the simplified solutions. The results in this paper can be used as a guide in NC part programming to select an optimal cutting strategy and to ensure a stable cutting process in ball end milling.

High-Precision Surface Grinding of Ceramics with Superfine Grain Diamond Cup Wheels

High-precision surface grinding has been performed on the Si 3N 4 and AI 2O 3-TiC ceramics and Mn-Zn Ferrite using an ultra-precision surface grinder and very fine grain diamond cup wheels, where the maximum depth of cut was 2 μm and the maximum through feed rate being 100 mm/min. The surface roughness and percent brittle mode area were measured using an atomic force microscopy (AFM). These characteristics were discussed by a parameter “ S max” defined as S max = μa v f/ v s (μ: successive cutting edge spacing, a: depth of cut, v f: through feed rate, v s: wheel speed). With decreasing grain size from #1200 to #16000, the surface roughness Rmax decreases to 20 to 30 nm. Similarly, a remarkable reduction in percent brittle mode area is seen by changing grain size. The effect of dressing stone on the ground surface was also investigated using 3D wheel surface topography.

Effect of Grain Shape on Cutting Force in Superabrasive Single-Grit Tests

Single grit microcutting and scratching tests were performed on steels and alumina with the use of CBN and diamond grains (#14-20). Both the tests were carried out using a reciprocating surface grinder. Thus, the cutting and grinding forces, as well as pile-up, were measured under different test conditions. In special, the effect of grain shape on the forces and pile-up was investigated. Microcutting speed ranged from 14 to 30m/min, and the maximum depth of cut was 25μm. Grinding speed was 12.7 and 30m/s, and the maximum depth of cut being 100μm. Normal cutting and grinding forces seem to be largely dependent upon grain shape. Also, it is evident that how the CBN grain differs in forces and pile-up from diamond grain.

砥石の切削に関する研究

The machining of grinding wheel is an important research problem related to wheel finishing process. This subject is also a typical example of ceramic composite material machining. However, there is insufficient information about this type of cutting. In this study, a turning experiment was performed on white alumina grinding wheels by the use of cemented carbide, sintered CBN and sintered diamond single point cutting tools. The cutting speed ranged from 0.003 to 150 m/min, the maximum depth of cut was 1.0 mm, and the feed was 0.6 mm/rev. Thus, the tool wear and cutting force were measured for various cutting conditions, and the optimum operating condition and mechanism of chip formation were obtained. The effects of cutting speed, rake angle, and nose radius were specially investigated. The cutting mechanism was also studied from a specially low speed orthogonal cutting experiment and FFT analysis. It is evident from this study that grinding wheel can be cut easily by using a proper cutting tool, such as K01 and sintered diamond tool, and by selecting relatively low cutting speeds, great negative rake angle and large nose radius. The chip is mainly formed by compressive fracture.

Analysis of the Cutting Process of a Cylindrical Workpiece Clamped by a Three-Jaw Chuck

A theoretical analysis has been carried out on the cutting dynamics of a solid cylindrical rotating workpiece clamped by a three-jaw chuck with balanced pressure at the jaws and subjected to a cutting operation. The net reaction balancing the cutting force is found to consist of infinite number of force components oscillating at frequencies 3ω, 6ω, 9ω ... etc., where ω is the angular speed of rotation of the workpiece, and a stationary force term 3F0/2 where F0 is the static balancing force impressed on each jaw-line. The stationary force term tends to give a uniform depth of cut. However the harmonic force terms tend to spoil the uniformity in the depth of cut. Under resonant condition of the third harmonic force maximum depth of cut occurs in the mid positions between two jaws and minimum along the jaw-positions. Resonant vibration of the system takes place at angular spindle speeds ωr = ω0/3P where P is an integer and ω0 = (K/M)1/2 is the angular natural frequency of vibration of the system.

部分安定化ジルコニアの研削機構の研究

The circular cutting with a single point diamond cutting edge, in which the depth of cut is very small and takes maximum at some point, is carried out for making clear a cutting process of partially stabilized zirconia under conditions similar to practical grinding, investigating sliding phenomenon of a diamond cutting edge, normal cutting force, groove profile, stock removal and so on. Main conclusions obtained in this study are as follows : (1) There are three different regions with depth of cut ; elastic, plastic and cutting region. (2) There are critical depths and critical normal forces at the beginning point of plastic deformation and cutting. (3) In the transitional cutting process, there are following three types of interference with maximum depth of cut ; (i) elastic region through the contact length, (ii) elastic-plastic-elastic, (iii) elastic-plastic-cutting-plastic-elastic. (4) Surface generation of a groove is performed by plastic deformation as well as brittle fracture.