Showing papers on "Honing published in 2018"

A new magnetorheological finishing process for ferromagnetic cylindrical honed surfaces

Abstract: In today’s industries, the internal surface finishing of cylindrical objects is highly demanded to improve their functional performance in various engineering applications. During the traditional honing operation, the finishing forces produced by abrasives on the workpiece surface are not easily controllable and also produce various surface defects. Therefore, to further improve the surface integrity of the traditionally cylindrical honed surface made of ferromagnetic or non-ferromagnetic materials, a new magnetorheological (MR) finishing process has been used with a controlled magnetic field. The experimentation is performed on the honed surface made of gray cast iron, which is generally used as a cylinder liner. The percentage change in surface roughness values, i.e., Ra, Rq and Rz, reduced by 77.44%, 70.16% and 72.16%, respectively, with better improvement in surface after 90 minutes of finishing. The experimental results demonstrated the effectiveness of present process for improving the funct...

Analysis of particles in magnetorheological polishing fluid for finishing of ferromagnetic cylindrical workpiece

Abstract: Magnetorheological honing process is developed for nanofinishing of internal surfaces of ferromagnetic and non-ferromagnetic cylindrical objects. The process makes use of smart fluid called magnetorheological (MR) polishing fluid for finishing which has a property to become stiff in the existence of magnetic field. The smart MR polishing fluid is made with the ingredients of carbonyl iron (CI) particles, abrasive particles, and base fluid. Direct current given to the electromagnet coil engenders magnetic field on finishing tool surface. Magnetic force acts on magnetic CI particles which further exert the repulsive force on nonmagnetic silicon carbide (SiC) abrasive particles and performs finishing when tool rotates as well as reciprocates inside the cylindrical workpiece. The CI and SiC particles present in MR polishing fluid are magnetically simulated and analyzed using finite element (FE) analysis. The distribution of magnetic flux density and magnitude of magnetic force acting on CI particles a...

Curved Measurement Theory of Honing Pneumatic Measurement System and Optimization of Measurement Parameters

Abstract: In the previous research on dynamic process of honing pneumatic measurement system are studied by measuring plane measurement instead of the surface, but to achieve high-precision measurement of aerodynamic honing, instead of surface measurement by plane measurement is not scientific. Based on the study of the theoretical basis of pneumatic measurement and air dynamics, through the dynamic study of nozzle baffle mechanism in the measuring system of gas honing, studies have shown that the measurement accuracy is higher than the baffle surface characteristic equation characteristic equation of plane baffle. Using this characteristic equation, the design of gas momentum meter and measurement system is more accurate, and it provides a reliable reference for improving the measurement accuracy of honing pneumatic measurement. For the equation of curved baffle property verification and optimization of the parameters of the nozzle, based on the entity model, gas path structure and nozzle of gas measuring device of dynamic curved baffle FLUENT software simulated. The simulation results show that the air flow changes during the operation of the pneumatic measuring device, and the pressure values are obtained. The pressure clearance curve of the curved baffle is plotted by drawing software, and the correctness of the characteristic equation of the surface baffle is verified by comparing with the theoretical curve. By adjusting the model parameters, the pressure clearance curves of different main and measuring nozzle apertures are obtained by repeated simulation. Then the law is found according to the results and the parameter design is optimized.

Study on ultrasonic-assisted electrochemical honing of bevel gears

Abstract: Electrochemical honing of gears is a productive, high-accuracy, micro-finishing and long tool life gear finishing process in which material is removed by combined action of electrolytic dissolution and mechanical scrubbing action. The use of ultrasonic-assisted electrochemical honing of gears is first proposed, and it may help to enhance the process performances of the classical electrochemical honing process by scrubbing the complete surface of the gear tooth. In this technique, the honing gear is attached on the ultrasonic vibrator to provide the ultrasonic vibrations on the workpiece surface. The focus is on an optimization of the process parameters of ultrasonic-assisted electrochemical honing of bevel gear made of AISI 1040 carbon steel. The result of experiments reveals that the applied high ultrasonic frequency (kHz) on the workpiece has the maximum influence on the process performance. The maximum percentage improvement in average and maximum surface roughness using ultrasonic-assisted electrochem...

Flow field analysis and parameter optimization of main and measured nozzles of differential pressure type gas momentum instrument based on CFD

Abstract: In honing online pneumatic measurement, the actual working conditions of honing have not been taken into account. While honing and online measurement of aerodynamic working environment is relatively small semi closed annular narrow space, various parameters will influence the movement characteristics of the measurement of gas, gas does not consider the previous online honing the actual working conditions of the dynamic measurement accuracy is hard to guarantee, does not meet the requirement of automatic processing of high precision. Through the combination of theoretical research and simulation experiment, through the study of honing, pneumatic measurement and aerodynamics, the characteristic equations of three working conditions under honing actual working conditions are obtained. Using fluid simulation software FLUENT to the actual working parameters of honing pneumatic measuring mechanism model is simulated, simulation results show that when the working temperature is less than the optimum value, to achieve amplification and linear range, complex parameter measurement, to meet the honing high dimensional accuracy and high shape precision and high automation requirements.

Development of Novel Fe-Based Coating Systems for Internal Combustion Engines

Abstract: Nowadays, combustion engines are the most common way to power vehicles. Thereby, losses occur due to cooling, exhaust gas and friction. With regard to frictional losses, highest potentials for optimization can be found in the tribological system of the inner surface of combustion chamber and piston ring. Besides friction, corrosive stress increases, e.g., due to utilization of exhaust gas recovery. In order to save energy, reduce emissions and enhance the life span of combustion engines, the demand for innovative coating material systems, especially for the inner surface of combustion chamber, increases. This study focuses on the development of innovative iron-based coating materials for the combustion chamber. As a first step, the plasma transferred wire arc and rotating single wire arc (RSW) technologies were compared using 0.8% C-steel as a reference. Subsequently, RSW was used for coating deposition using an innovative iron-based feedstock material. In order to improve wear and corrosion resistance, boron and chromium were added to the feedstock material. After deposition, different honing topographies were manufactured and compared under tribological load. Furthermore, electrochemical corrosion tests were conducted using an electrolyte simulating the exhaust gas concentrate. Especially with regard to corrosion, the novel coating system FeCrBMn showed promising results.

A reliability optimization allocation method for the hydraulic system of CNC honing machine considering the operating condition information

Abstract: In recent years, reliability optimization allocation has drawn a broad spectrum of attentions, especially for complex systems consisting of a large number of subsystems and components. Hydraulic system, deemed as a complex system, plays a great role in reliability increment of the CNC honing machine. In order to realize the CNC honing machine tool’s balanced operating performance, the crucial hydraulic system is designed to obtain the optimal and well-balanced allocation solution under the constrains of cost and reliability. Meanwhile, the quantified operating factor that influences the allocation solution is rarely considered adequately when operating samples are insufficient. So, if hydraulic systems are used in a new required longer operating mission duration or a new severer operating environment, the dissatisfied reliability could not be better reallocated to adapt to this environment with appropriate methods. Aimed at overcoming the abovementioned shortcomings and optimizing the dissatisfied reliabi...

Honing the 21st Century Characteristics of Lecturers in the Faculty of Education for Effective Job Performance.

Abstract: Teachers all over the world are now facing the challenges of the 21st century education as they face the 21st century learners. To cope up with the demands of the 21st century education, teachers, most especially teachers in the Colleges of Education, need to possess the 21st century characteristics. This study was conducted to assess the extent of the acquisition of the different 21st century characteristics of an educator among the faculty members of the College of Education of Bulacan State University and eventually proposed an enhancement program for the teachers. The respondents of the study were the thirty-one faculty members with teaching load during the short term classes of academic year 2015-2016. Questionnaire was the principal instrument used in this study to measure extent of acquisition of the 21st century characteristics of an educator. Quantitative method of research was employed and frequency, percentage and weighted mean were the statistics used in the study. The result of the study indicates that the respondents acquired the different 21st century characteristics of an educator to the large extent. In the light of the foregoing results, conclusions and recommendations were suggested: the school as envisioned being a recognized leader of excellence in instruction the suggested enhancement/intervention program for the faculty members may be adapted to address the needs of the 21st century education; as the teachers continue to develop their potentials and skills in line with the needs of the 21 century education the school administrators also need to update themselves; and full supports from the administrators are needed most especially in the development and construction of different needed 21 century education laboratories.

Connecting-rod deep hole grinding method for marine low-speed diesel engine and special honing device

Abstract: The invention provides a connecting-rod deep hole grinding method for a marine low-speed diesel engine and a special honing device. The connecting-rod deep hole grinding method comprises the followingsteps: 1, grinding machined traces at a rounded corner of a deep hole by using a long-handle plane grinding head; 2, grinding relatively deep vibration knife marks and machined traces as well as spiral lines near an orifice of the deep hole by using a plane grinding head; 3, grinding and smoothening the entire hole wall by using the special honing device, wherein the special honing device comprises a honing head, a universal quick-change adapter and a pneumatic motor and is mounted on an extension rod, the hole wall of the deep hole is tightly supported through an elastic structure, the special honing device is driven by a pneumatic grinder to rotate, the rotating speed of the special honing device is adjusted by using a speed reducer, and then the uniform and efficient deep hole grindingoperation is achieved; 4, grinding burrs and shallow traces in the deep hole by using a sand impeller head; 5, removing waste and burrs on the hole wall by using a steel wire brush; 6, cleaning the hole wall; and 7, carrying out repairing and grinding till quality testing is passed. According to the connecting-rod deep hole grinding method provided by the invention, the grinding effect is uniform, the operation is simple, both the time and the effort are saved, and the entire grinding effect on the deep hole in a connecting rod is improved.

Assessment of the effect of cutting parameters on roughness in flexible honed cylinders

Abstract: This study aims to investigate the effect of the three cutting parameters (rotation, feed rate, and number of tool strokes) on the values of roughness (Rk, Rpk, Rvk, Mr1, Mr2, Rp/Rt ratio, and Vo) in flexible honed crankcase cylinder of hermetic compressors. The study was based on a full factorial design 2 × 2 × 3, where the rotation and the feed rate were investigated in two levels and the number of tool strokes in three levels. The cylinders were initially honed using a multi-spindle honing machine, Gehring model. A set of three honing tools was used each with two strokes, the first for roughing (120 mesh), the second for semi-finishing (270 mesh), and the third for finishing (600 mesh). For conventional honing (CH), the depth of the cut and the feed rate were kept constant. The flexible honing process was carried out after conventional honing (C+FH) in a CNC milling machine using a Silicon Carbide flex hone tool 800 mesh and 24.2 mm nominal diameter considering 12 different cutting conditions. An electromechanical surface roughness tester was used to carry out roughness measurements. The measurement uncertainty was assessed following the recommendations of the GUM-JCGM 101. The analysis of variance (ANOVA) technique was applied, and it was observed that the number of the tool strokes was the factor that contributed the most to the improvement of the surface finish of the cylinders.

An optimization study for the surface quality of the honing process

Abstract: In this study, it is aimed to experimentally optimize the interior honing process, which is applied to improve surface roughness of the internal cylinder surfaces of the hydraulic cylinders in a privately owned company. The hydraulic cylinders produced in the company are used in heavy construction machineries. In the application, the optimal values of the critical honing parameters are determined by applying two different experimental design approaches namely, Taguchi and response surface methodologies separately and compared. For interior honing process, linear speed of the honing head, tangential speed of the cylinders and abrasive grain size are considered as critical parameters in the minimization of the surface roughness in the study. Experimental results are provided to illustrate the effectiveness of the application.

Investigation on formation mechanism of surface texture and modeling of surface roughness with internal gear power honing

Abstract: In order to understand the formation mechanism of surface arc texture of internal gear power honing, the contact line equation of tooth surface is derived with homogeneous coordinate transformation method, which is based on the involute helical tooth surface equation of honed workpiece gear as well as the meshing principle of space surface. Then the influence of shaft angle Σ on the formation of surface arc texture of workpiece is analyzed. The results of imager and three-dimensional (3D) profilometer are in accordance with the theoretical derivation. In order to analyze the influence of the power honing process parameters on the surface roughness, a central composite surface design method based on response surface methodology (RSM) is proposed in a range of process parameters. Based on this, a regression model of surface roughness for the honed workpiece gear is established. Meanwhile, the influence of power honing process parameters on the surface roughness of honed workpiece gear is analyzed. The process parameters are the honing wheel speed nH, Z feed fZ, and X feed fX. The three-dimensional profilometer is utilized to analyze the roughness value with a set of process parameters, based on which the accuracy and reliability of the model can be verified. The results show that the surface arc texture is suitable for producing dense textures when the shaft angle Σ is within 5° to 10°. According to the analysis, nH has the greatest influence on the surface roughness of the honed workpiece gear. The effects of fZ and fX are almost the same when Ra ≥ 0.4 μm, and while Ra ≤ 0.3 μm, the effect of fZ is slightly higher than that of fX, Ra is the regression value obtained after the honing process. Based on the mention above, the surface quality of the honed workpiece gear can be predicted and controlled before honing.

Performance of pulsed-electrochemical honing and pulsed-electrochemical finishing in improving quality of bevel gears

Abstract: This article presents a comparative study concerning performance of pulsed-electrochemical honing (PECH) and pulsed-electrochemical finishing (PECF) in straight bevel gear finishing. Performance of these processes were compared in terms of average percentage difference in the considered parameters of surface features of bevel gear namely average percentage differences in average surface roughness ‘PDR a ’, maximum surface roughness ‘PDR max ’ and depth of surface roughness ‘PDR z ’, micro-geometry (i.e. average percentage differences in single pitch error ‘PDf p ’, adjacent pitch error ‘PDf u ’, cumulative pitch error ‘PDF p ’, and percentage difference in runout ‘PDF r ’) and finishing productivity (i.e. material removal rate ‘MRR’). Microstructure and microhardness were also considered as measure for performance assessment. Observed results show PECH is proficient in simultaneously improving all the considered responses of bevel gears by more than 50% as compared to PECF. The PECH-finished gear additionally displayed unrivalled microstructure and better microhardness when contrasted with PECF-finished gear. These changes will upgrade the working-life and operating performance of the finished gear.

Influence of the abrasive grain trajectory on the machining of thin-walled cylinder liners of internal combustion engines with variable kinematics of honing

Abstract: Honing with variable kinematics has a number of advantages in comparison to traditional honing [1-19], such as less tool wear [12, 13], lower processing temperature [13], better surface quality [12, 13] and less deviation of cylindricity [13]. The article discusses the influence of the variable kinematics on the machining process.

Honing oilstone and preparation method and application thereof

Abstract: The invention discloses a honing oilstone and a preparation method and application thereof. The honing oilstone comprises copper, tin, zinc, silver and superhard materials, and further comprises antimony, ferrophosphorus alloy, sodium hexafluoroaluminate, bronze, lubricant and wetting agent, wherein the feeding mass ratio of the copper, tin, zinc, silver, antimony, ferrophosphorus alloy, sodium hexafluoroaluminate, bronze, lubricant and wetting agent is 40-80:10-30:1-10:1-5:1:1-3:1-10:1-3:1-3:0.1-1, and the honing oilstoneis formed by mixing and sintering the raw materials. The preparation includes the steps of weighing raw material except the superhard materials according to the formula, mixing each weighed raw material with the superhard materials, sintering the mixture, and obtaining the honing oilstone. The application is the application of the honing oilstone in processing stainless steel materials. When the prepared honing oilstone is used to process materials difficult to process, such as stainless steel, no cutter adhesion, high precision and good processing surface integrity can be achieved, the preparation of the honing oilstone is simple, the cost is low, and the processing efficiency is high.