Showing papers on "Honing published in 2009"

Investigation into magnetorheological abrasive honing (MRAH)

Abstract: A scheme to finish external curved surfaces, by imparting rotation while the abrasive-mixed magnetorheological fluid (or abrasive-mixed MR fluid) is pushed up and down, is presented in this paper. Since the relative motions resemble those present in conventional honing, the proposed method is named as ‘Magnetorheological Abrasive Honing’ (MRAH). This paper outlines the design and development of magnetorheological abrasive honing setup. A DC electromagnet with cylindrical pole faces is used and measurement for magnetic flux density is done. Experiments are conducted with aluminum and austenitic stainless steel workpieces to understand the effect of magnetic field. Effect of initial roughness, workpiece rotation and process duration on finishing was investigated with ground austenitic stainless steel workpieces. It is observed that the improvement in finish is better for rougher surface and higher rotation speed of workpiece and a reduction in roughness is consistent with process duration.

Applied Machining Technology

Abstract: Fundamentals of machining explained for turning.- Tool life T.- Tool- and machine curves.- Metal removal rate and chip volume ratio.- Cutting materials.- Turning.- Planning and slotting.- Drilling.- Sawing.- Milling.- Broaching.- Grinding.- Abrasive cutting.- Abrasive belt grinding.- Honing.- Superfinishing (shortstroke honing).- Lapping.- Further refinement of the cutting materials.- High speed cutting (HSC).- Cutting fluids (coolants and lubricants).- Cutting force measurement in machining.- Tables for general use.

Process variability in honing of cylinder liner with vitrified bonded diamond tools

Abstract: With the increasing use of ultra-hard abrasives and the introduction of more powerful and rigid machines, honing process is spreading its performances. In industrial honing of cylinder liners for internal combustion engines, the degree of penetration that Metallic Bonded Diamond (MBD) abrasive stones have experienced compared to conventional Vitrified Bonded Silicon Carbide (VBSC) tools is obvious. The long tool life of metal bonded diamond sticks is however balanced by its main role in producing torn and folded metal without cutting-effect finish. To simultaneously reduce folding and remove the stock with improved stone life, an experimental investigation is reported on the process variability in finish honing behavior due to stone inconsistency and nature of its properties. We consider the achievable performances by finish honing of cast iron liners with a new abrasive stone. This superabrasive consists of micro-sized diamond abrasives which are bonded with vitrified bond (VBD). By selection of finer grit abrasive while honing with VBD tool, conditions could be created that gave a cutting-effect finish to the diamond honing and minimized the folding over.

Effect of finishing methods on surface characteristics and performance of precision components in rolling/sliding contact

Abstract: Functional performance of precision mechanical components such as bearings is known to depend on their surface characteristics, which result from the finishing method used. However, a detailed study of the impact of modern finishing methods on surface integrity, and tribological and mechanical performance is needed to fully understand the complex relationship for bearing steel surfaces prepared using the following methods: Grinding (GD), Honing (HN), Hard Turning (HT) and Isotropic Finishing (IF). This paper presents the results of an experimental study aimed at understanding the complex relationship of these finished surfaces subjected to rolling?sliding lubricated contact. The resulting Three-Dimensional (3D) texture and residual stresses, and their influence on rolling/sliding friction, torque, temperature and bearing life are evaluated. Specific surface features are identified to explain the observed trends.

Multi-response optimization of electro-chemical honing using utility-based Taguchi approach

Abstract: This paper presents a utility-based Taguchi loss function strategy for the multi-response optimization of electro-chemical honing (ECH) process. ECH is a precision micro-finishing technology that hybridizes electro-chemical machining and conventional honing principles to provide controlled functional work surface-generation and fast material removal capabilities in a unique single operation. The approach utilizes a composite utility function using the Taguchi loss functions of multiple ECH responses in selecting the optimal parametric settings such that the overall functional utility of the product is maximized. The use of the Taguchi loss functions ensures the process is robust against the random variations. Actual experiments confirm the feasibility of the strategy over a wide range of machining conditions employed in ECH.

State-of-art-review of electrochemical honing of internal cylinders and gears

Abstract: This paper is an attempt to present a state-of-the-art review of two major applications of electrochemical honing (ECH) for internal cylinders and gears, which are the most commonly used parts in numerous engineering applications. ECH is a hybrid process of electrochemical machining (ECM) and mechanical honing, combining the fast material removal capabilities of ECM and controlled functional surface generating capabilities of mechanical honing in a single operation. ECH is a precision micro-finishing process capable of producing excellent surface quality having a cross-hatch lay pattern required for lubricating oil retention, compressive residual stresses required for the components subjected to cyclic loading, and completely stress-free surfaces. Furthermore, it provides these benefits productively. It makes ECH an ideal choice for superfinishing, improving the surface integrity, and increasing the service life of the critical components such as internal cylinders, transmission gears, carbide bus...

Identification of significant parameters and appropriate levels in honing of cylinder liners

Abstract: Surface topography of cylinder liners influences the functional behaviour of internal combustion engines. The cylinder liners after boring operation are subjected to rough, finish and plateau honing operations in which parameters such as rotary speed, reciprocating speed, pressure and honing time are selected on the basis of operator's experience. The present work is a comprehensive investigation carried out to identify the significant honing parameters and their values for different honing operations. The honing trials are carried out according to design of experiments. Before each operation, all cylinder liners are processed identically under conditions identified from the previous operation. Parameters considered for characterising the surface topography are roughness average (Ra) and all five bearing area parameters (Rpk, Rk, Rvk, Mr1 and Mr2). It is established in the present work that Ra can be replaced effectively by Rk in finish and plateau honing operations to control the final surface topography and these parameters (Ra, Rk) are influenced by honing pressure. For the most important bearing area parameter Mr2, the significant process parameters are medium honing time in finish honing and high reciprocating speed in plateau honing. These results are useful for controlling the honing operations during the manufacture of the cylinder liners.

Magnetic field analysis and roughness prediction in magnetorheological abrasive honing (mrah)

Abstract: Magnetorheological Abrasive Honing (MRAH) is a recently developed process to finish engineering surfaces. The process makes use of a magnetically stiffened abrasive-mixed magnetorheological fluid as the flexible tool and rotation-cum-reciprocation movements between the finishing medium and the workpiece surface for providing finishing action. In the present work, a finite element analysis with Mechanical/Emag module of ANSYS is performed to understand the nature of magnetic field developed in the process and verification is done with actual measurements. Considering the simulated magnetic field, a model to predict final roughness value (R a ) is developed. The model, when applied for different work materials and various process parameters, such as magnetic flux density, process duration and workpiece rotation, yields results that are in good agreement with experimental results.

Cylinder liner mechanical processing technique

Abstract: The invention provides a mechanical processing technique for a cylinder jacket. The mechanical processing technique comprises the following steps: rough machining, rough honing of an inner hole and finishing machining. The step of rough honing of the inner hole is moved after the step of rough machining and before the step of finishing machining, and is carried out after the step of finish boring or finish reaming, so that the grinding head in the rough honing step can be used for honing the inner hole of the cylinder jacket under lower expansion-contraction pressure, so as to achieve the purposes of removing the surplus of the surface of the inner hole of the cylinder jacket and modifying the shape error of the inner surface. The precision of the honed inner hole is high, the error is greatly reduced, so that the error of finish turning of the excircle or the supporting shoulder in the finishing machining step can be greatly reduced, the error superposition in the finishing machining step can be basically stopped at the beginning, therefore, the precision of the inner circle and the excircle of the cylinder jacket is improved, and the finally obtained cylinder jacket can meet the standards.

Modelling of fluid continuum considering 3D surface parameters in hydraulic assemblies

Abstract: Friction in servo hydraulic assemblies reduces the response characteristics of the system. The friction is influenced by various factors including the geometry (form and surface errors) of the sliding surfaces. In this work, functionally significant 3D surface parameters from the Birmingham parameters are investigated for reduced friction. A 3D surface modelling approach is presented using random process modelling as the basis. An exponential decay areal autocorrelation function is used to model the grinding and honing processes which are commonly employed for the manufacture of the hydraulic assemblies. Honed surface is modelled with the crosshatches of appropriate angle. Method of surface modelling is validated using the data obtained through measurements on a practical surface. Different surface maps with varying surface parameters of the ground and honed surfaces are generated. The fluid continuum gap geometries of the hydraulic assemblies are modelled using these surface maps as envelopes. Pressure distribution, velocity and viscous friction force are used as measurands of the frictional characteristics. Using computational fluid dynamics (CFD) approach, these measurands are evaluated for different functionally significant Birmingham parameters. Based on further analysis, negative skewness, lower kurtosis values, higher valley fluid retention index were found to have lower frictional characteristics.

Technique for processing honing tube

Abstract: The invention relates to a processing technique for a honing pipe in the fields of aerospace and pressure machinery and the like, in particular to the processing technique for the honing pipe with the tensile strength of not less than 1,140 MPa, the yield strength of not less than 1,030 MPa, the tensile stretch of not less than 16 percent and the specific elongation of not less than 38 percent, and higher requirement on the processing precision. The adopted process is to select a TC4 titanium alloy bar material with proper dimension to finish the processing of the honing pipe with the stated dimension and requirements through the steps of straightening, boring deep holes, honing, turning, polishing and the like according to the processes of roughing, open die forging and heat treatment. The processing technique is simple and efficient with low cost, and satisfies the use requirements on high-performance honing pipes in the fields of aerospace and pressure machinery and the like in China.

Analysis of the influence of gear dimensions on cutting speed and contact conditions during the gear honing process

Abstract: In many cases, gear honing represents a cost-efficient process for gear manufacturers. Another advantage of gear honing is the generation of a surface structure on the tooth flank which improves the noise behavior of the gear. Previous research activities have resulted in reliable gear honing processes, particularly for automotive gears with a tip diameter of up to 150 mm. Problems occur, however, when honing larger gears with a tip diameter of more than 150 mm, thereby rendering a robust manufacturing process is difficult. In the course of this paper, an analysis will be carried out of the geometrical and kinematic conditions that will lead to a better understanding of the process. The aim of this report is to provide an overview of the current basic conditions of the gear honing process. Theoretical studies are conducted to identify differences in gear honing processes with various tip diameters. This analysis forms the basis for optimizing process design, with the aim of generating a cost-efficient gear honing operation for gears with a tip diameter of more than 150 mm.

Honing feed system and method employing rapid tool advancement and feed force signal conditioning

Abstract: The honing feed system and method utilizes feedback from various sources during rapid feeding of the honing tool while rotating and stroking, to detect initial contact with a bore surface, to slow the feed to a normal honing rate, involving conditioning the feedback signals to eliminate noise factors such as the stroking movement and forces generated to rotate and feed the tool unopposed.

Modelling of bore honing

Abstract: This paper discusses the modelling of deep holes honing. The dynamic model of honing, including the models of tool dynamics, cutting forces calculation, and new surface formation, are presented. The tool frequency characteristics, method of numeric calculation of machined surface and integral criteria of the surface distortion from an ideal cylinder are analysed based on the designed model.

Method for processing sleeve of vehicle steering valve

Abstract: The invention relates to a processing method of a valve housing of an automobile steering valve, including the following steps: lathe machining, drilling, rough slotting-precision boring of an inner bore-finish slotting and honing the inner bore; wherein, in the step of rough slotting-precision boring of an inner bore-finish slotting, rough slotting of six slots is firstly carried out, a margin of 0.1mm is kept, then precision boring of the inner bore is carried out, a honing margin of 0.05mm is remained, the burrs after rough slotting are removed and then finish slotting of six slots is carried out. Compared with the prior art, the valve housing of the steering valve produced by the method can greatly raise the first-time qualification rate of the assembly of the steering valve, the performance curve of the steering valve is stable and has small fluctuation, and the noise of a steering engine can be significantly lowered.

Sintered cubic boron nitride tool

Abstract: A sintered cubic boron nitride tool can perform stable machining without causing any defect for a long lifetime even under a high-load cutting condition and a high-efficiency cutting condition. The sintered cubic boron nitride tool is such that: assuming a reference length longer than five times an average particle size of cubic boron nitride is S, when a total length of profile curves of cubic boron nitride included in the reference length S of the chamfer honing surface is LCC, when a total length of profile curves of the binder phase included in the reference length S of the chamfer honing surface is LCB, and a ratio of LCC to LCB is PC(PC=LCC/LCB), and when a total length of profile curves of cubic boron nitride included in the reference length S of the round honing surface is LRC, a total length of profile curves of the binder phase included in the reference length S of the round honing surface is LRB, and a ratio of LRC to LRB is PR(PR=LRC/LRB), then, a ratio of PR to PC (PR/PC) satisfies the relation of 1.2≦PR/PC≦8.0.

Method for helical boring

Abstract: A tool may be used to form an engine cylinder bore in a compacted graphite iron workpiece using helical interpolation. The tool may be rotated about a first axis while orbiting about a second axis that is parallel to the first axis. While rotating and orbiting, the tool may be advanced into the workpiece. This helical interpolation may be used to successively engage cutting or honing elements of the tool with the workpiece. The elements may thereby be permitted to cool between each successive engagement, which may reduce wear on the tool. Various operating parameters associated with the process may have certain relationships that may be exploited in certain ways to obtain ideal results. For instance, a helical interpolation process may be used to perform an act of rough cutting on the workpiece and finish honing on the workpiece, without having to perform an intermediary step of semi-finish boring.

Device for treating blades to improve their cutting properties

Abstract: A treatment device for improving the cutting properties of the blade of a non-electric shaving razor. The device has a treatment surface for interacting with the cutting edge of the razor blade, as the blade is put into sliding contact with the treatment surface. The treatment surface has a plurality of resilient honing projections that are compressed as the blade is moved in sliding contact with the surface.

Reciprocating stroke control device of numerical control honing machine

Abstract: The utility model relates to a stroke control device of a honing machine, in particular to a reciprocating stroke control device of a CNC (computer numerical control) honing machine The control device comprises a transmission mechanism and a rotary encoder (5); wherein, the input end of the transmission mechanism is connected with a main shaft (1) of the honing machine, and the output end of the transmission mechanism is connected with an input shaft of the rotary encoder (5), thus converting the reciprocating linear motion of the main shaft (1) of the honing machine into the rotary motion of the input shaft of the rotary encoder (5); however, the signal output end of the rotary encoder (5) is electrically communicated with the input end of a controller which can control the motion of the main shaft (1) on the honing machine The reciprocating stroke control device replaces the method of detecting the position of the main shaft by a machinery in the prior art with the method of detecting the position of the main shaft by the rotary encoder, thus enhancing the controlling precision and sensitivity; moreover, data can be set by a human-computer interface of a PLC (programmable controller), thus being convenient for changing the stroke and direction-changing points of the main shaft, and further realizing an extremely small reciprocating stroke

Precision microfinishing by electro-chemical honing

Abstract: Surface condition and shape deviations produced by manufacturing processes have pronounced influence on the functional performance of engineering components. This paper reports a comprehensive study on the influence of several key process parameters of Electro-Chemical Honing (ECH), a precision microfinishing technology, on dominant machining criteria the surface roughness improvement. The current intensity, electrolyte concentration, stick-out pressure and stick grit-size are found to be the major players influencing the response significantly. With distinct coordination of electrolytic dissolution and mechanical scrubbing, ECH can be utilized as a precision microfinishing process for critical components of tribological significance. More than 90% improvement in surface finish with precisely controlled shape deviations can be achieved. Important features of the ECH setup that was designed and developed indigenously are also highlighted.

Parametric Study of Process Parameters and Characterization of Surface Texture Using Rotational-Magnetorheological Abrasive Flow Finishing (R-MRAFF) Process

Abstract: In this paper an effort is made towards improving the performance of MRAFF process by providing a rotating magnetic field externally to the polishing medium by using permanent magnets in addition to the reciprocating motion provided to the polishing medium by a hydraulic unit. This finishing process creates a smooth mirror like finished surface with a few directional cutting marks (i.e. hatch pattern like honing) on the finished surface of stainless steel, brass, and EN-8 workpieces. Preliminary experimental study is conducted on MRAFF and rotational (R)-MRAFF processes to compare their process performance in terms of change in Ra (ΔRa ) and change in material removal (ΔMR). Later complete experimental study of R-MRAFF process is carried out using central composite rotatable design (CCRD) and the responses are plotted using response surface methodology (RSM). Optimum finishing conditions are identified by optimization method developed by Derringer and Suich using Design-Expert® software. The present study shows that rotational speed of the magnet has significant effect on output response (%ΔRa ). The finished surfaces are characterized in detail by atomic force micrographs (AFM), and scanning electron micrographs (SEM) to analyze the changes in surface generation at different RPM.© 2009 ASME

Method for fine honing of inner surface especially a cylinder bore in an IC engine by combined axial and rotational movement of the milling head

Abstract: A method for fine honing of the inner surface of a workpiece, especially the cylinder bore in an IC engine, has the honing head performing axial and rotational movements w.r.t. the workpiece. Periodic rotational movements with several rotational movements for each axial cycle overlay the periodic axial movements. This produces a crossed honing pattern which is best suited to the material of the cylinder liner/block and ensures optimum lubrication. Alternatively the periodic rotational movement is held constant while the periodic axial movement is modulated.

Collapsible honing head

Abstract: The invention discloses a collapsible honing head, relates to the technical field of honing and aims at solving the technical problem that the prior collapsible honing head is incapable of directly honing a workpiece with a groove or gap wider than a single oilstone The honing head comprises a shell, a collapsible element which is arranged on the shell and is collapsible in the radial direction, an oilstone seat arranged on the collapsible element and an oilstone arranged on the oilstone seat The honing head is characterized in that the oilstone seat is an open lantern ring sleeved and fixed on the collapsible element; the peripheral surface of the open lantern ring is provided with at least one oilstone in parallel along the axial direction; and the open lantern ring and the oilstone can swell and shrink along with the collapsible element Due to the utilization of the collapsible honing head, the labor productivity and the product quality can be improved