Showing papers on "Honing published in 2012"

The effect of groove texture patterns on piston-ring pack friction

Abstract: A cylinder liner possesses fairly intricate surface requirements due to its complicated functions. It needs to provide adequate surface roughness to resist wear as well as to store and retain lubricants during high temperatures. The liner surface texture is anisotropic, produced by the honing process, with resultant deep visible scratches left on it [1] . The prominence of the honing grooves observed suggests that surface texture significantly affects ring-pack performance, although this effect is not clearly understood. In this paper, a numerical model was developed to investigate the effects of groove characteristics on the lubrication condition and friction at the interface between the piston ring and cylinder liner. This model aims to solve the average Reynolds equation, which depends on the real surface topographies of the cylinder liner, and describes the influence of surface irregularities on the lubricant flow under hydrodynamic lubrication conditions, considering lubricant film rupture and cavitations. Numerical results help to determine the optimum lateral groove characteristics to reduce friction and then noxious emissions.

Investigation on Dimples Distribution Angle in Laser Texturing of Cylinder–Piston Ring System

Abstract: The effectiveness of laser surface texturing in reducing wear rate was studied, with emphasis on dimple distribution angle. Experiments were performed by varying the texturing parameters to derive variational rulesof the wear scar depth on laser-textured cylinder walls under starved lubrication conditions, and the optimum laser texturing dimple distribution angle was obtained. It was found that the laser texturing could result in less wear rate compared to mechanical honing.

Optimisation of Cylinder Liner Surface Finish by Slide Honing

Abstract: Cylinder liner surfaces are often on the agenda of engine developers because of their large influence on the frictional losses, oil consumption and emissions of internal combustion engines. Improving the liner function involves not only manufacturing new surfaces and checking their function but also characterising them as a necessary intermediate step for better understanding of the changes made. In the manufacturing of the liners, honing is a well adapted and widely used finishing process and along with the characterisation and function has been the subject of studies in this thesis. Regarding the liner’s function, three phenomena were monitored: wear, friction and oil passage rate (correlated with engine’s oil consumption). The first one was studied experimentally while the other two were simulated. Only the interactions with the twin land oil control ring were simulated as it has the greatest influence on the control of friction and oil consumption of all other rings. In the mid-stroke region of truck engine liners, the presence of axial wear scratches was observed and their relation with the removal of the cold worked material (“Blechmantel”) folded inside the deep honing grooves was investigated. Algorithms were developed for estimating the extent of Blechmantel, revealing that most of it remained on the surface whereas the engines still performed well. Other algorithms for characterising honing angle, balance of honing texture, width, height, distance between honing grooves/axial wear scratches, etc were developed for quicker and more objective inspection of unworn and worn surfaces from 3D interference measurements. Based on such 3D measurements, the algorithms were incorporated in a characterisation tool enabling rating of the surfaces and determining the number of measurements necessary to achieve stable roughness parameter values. In addition, it was found that interference measurements are more suitable for quantification of the deposits on the worn truck liner surfaces compared with scanning electron microscope measurements. The lubrication and friction of flat oil control ring lands and differently slide honed surfaces of truck liners were simulated. Friction mean effective pressure and oil passage rate were calculated for each surface showing in each case a reduction for the surfaces with smoother plateaus and smaller valleys. Such a liner surface was finished by using a low base honing pressure and a longer plateau honing time. In a car engine, the influence of different liner surfaces, ring land widths and tensions was examined by running simulations. The results suggest that a considerably improved function can be achieved if the ring land width and tension are reduced whereby the differences between the liner surfaces would reduce.

The Scale Effect of Roughness on Hydrodynamic Contact Friction

Abstract: Multistage abrasive finishing processes (grinding, polishing, honing, etc.) are commonly used to produce the geometrical properties of a surface to meet its technical functionalities in the operating characteristics of contacting parts in friction, relating to their durability and reliability (running-in performance, wear resistance, load-carrying capacity, etc.). Coarse abrasive grits followed progressively finer ones are used, which leads to a multiscale stratified surface texture. In this article, a numerical model of elastohydrodynamic (EHD) contact coupled to a multiscale surface texture model was developed that allows tracking the scale effect of surface features and their interactions on friction performance and lubricant flow under hydrodynamic lubrication conditions. Because the simulation model has as an input the surface topography and to overcome the variability in surface finish formation, textured surfaces at different stages of the finishing process were simulated (virtual texturing method)...

Macroscopic simulation of the liner honing process

Abstract: The form quality, the roughness and the surface appearance produced by honing minimizes the friction of the piston in the liner. The process is however mechanically complex and the selection of the process parameters is currently based on empirical methods. The aim of this paper is thus to develop a macroscopic simulation environment of complete real honing cycles, which will help end-users during the setting-up. This virtual tool is based on a space–time discretization and a macroscopic cutting model taking into account local contacts between the workpiece and the abrasive tool. The space–time discretization allows representing the machine environment with the tool, the workpiece and the kinematics. Simulation results are finally validated by comparison with industrial experiments.

The influence of honing process parameters on surface quality, productivity, cutting angle and coefficients of friction

Abstract: Purpose – The purpose of this paper is to explore the influence of tool kinematics parameters on surface roughness, productivity and cutting angle for grey cast iron cylinder liners machined by normal honing.Design/methodology/approach – For experimental investigation, a long stroke honing system was used. Diamond and SiC tools were used, for pre‐ and finishing, respectively. The values of cutting parameters were varied within the following limits: cutting speed vs=0.931‐1.11 m/s; specific pressure of pre‐honing process pd=1.0‐1.4 N/mm2 and specific pressure of finishing honing process pz=0.2‐0.5 N/mm2. The analysis of dispersion was conducted for determining the mathematical model for cutting parameter influence on surface roughness and productivity.Findings – Dispersion analysis proved that the most influential parameters on maximum roughness depth are cutting speed for D181 tool and specific pressure of finishing honing for D151 tool. The most influential parameter on productivity in the honing process...

Effects of electrolyte composition and temperature on precision finishing of spur gears by pulse electrochemical honing (PECH)

Abstract: This paper presents the experimental findings to explore the effects of electrolyte in improving surface quality of gear teeth profile during precision finishing of spur gears by pulse electrochemical honing (PECH) process. Electrolyte composition and electrolyte temperature were used as input process parameter while percentage improvement on average and maximum surface roughness values (PIRa and PIRtm) was used as measure of process performances. The experimentation was carried out in an indigenously developed experimental setup for PECH. Optimum values of electrolyte composition and electrolyte temperature have been estimated using graphical analysis. Work-samples were analysed before and after the process using optical profilometer to visualise the improvement in surface finish of gear teeth profile. Key features of the developed PECH setup are also highlighted.

Process for machining thin-wall air cylinder sleeve

Abstract: The invention discloses a process for machining a thin-wall air cylinder sleeve. The process comprises the following steps of: boring an inner hole roughly, lathing an outer circle and two end faces roughly, performing aging treatment, performing semi-lathing on the outer circle, positioning two heads, reaming the inner hole precisely, honing the inner hole roughly, lathing the outer circle precisely, performing dual-feed honing on the inner hole (hauling and polishing once) and grinding the outer circle precisely. The process has the advantages of high work efficiency, low manufacturing cost, high product accuracy and low rejection rate.

Method for completing high-precision machining of valve body hole series on machine tool of machining center.

Abstract: The invention provides a method for completing high-precision machining of a valve body hole series on a machine tool of a machining center. The method comprises the following steps: milling is firstly completed; then a valve body is clamped on the machine tool of the machining center; after the valve body is drilled, expanded, bored and reamed, a rough honing knife, a semi-microhoning knife and a microhoning knife are mounted on the machine tool of the machining center; and vertical honing is completed through once clamping. The method has the advantages that a vertical honing machine is cancelled, and vertical honing is completed on the machining center, so the steps of drilling, expansion, boring, reaming and vertical honing can be completed only through once clamping; since the valve body only needs to be positioned once, the machining precision is greatly improved, the machining time is reduced at the same time, the input cost of equipment is lowered, the production efficiency is improved, the valve hole machining precision is improved by multiple grades, and the valve body is matched with a valve core and can be completely interchanged with the valve core.

Method and Machining Installation for the Finishing of a Crankshaft Bearing Bore

Abstract: In a method for the finishing of a crankshaft bearing bore in a cylinder crankcase of an internal combustion engine, starting from a prepared crankshaft bearing bore, a finished crankshaft bearing bore is produced with a prescribable desired size, a prescribable desired structure of the bore inner surface and a prescribable desired position of the bore axis. The prepared crankshaft bearing bore is first finished with at least one finishing tool with a geometrically defined cutting edge and then the honing of the crankshaft bearing bore is carried out. In a final finishing operation with a geometrically defined cutting edge immediately preceding the honing, an allowance of at least 0.4 mm is removed, and the honing tool is introduced into the bore coaxially in relation to the desired position of the bore axis and moved within the bore, an allowance of at least 0.08 mm being removed during the honing.

High-precision multifunctional intelligent machine tool

Abstract: The invention provides a high-precision multifunctional intelligent machine tool and relates to a numerically-controlled machine tool. A machine tool body is provided with an inclined guide rail; an automatic tool changer and a honing device are respectively arranged on the inclined guide rail; the right end of the machine tool body is provided with a replaceable tail rack; the front surface of the machine tool body is provided with a Z-direction ball screw I; the side surface of the machine tool body is provided with a Z-direction ball screw II; the upper end of the Z-direction ball screw I is provided with a sensor I and a sensor II; and the upper end of the Z-direction ball screw II is provided with a sensor III and a sensor IV. The machine tool adopts a photoelectric detection technology and a design with a tool rest autosteerer, the honing device and the replaceable tail rack; a processing program is set by virtue of a closed-loop control system so as to perform real-time control on the processing quality, multifunctional integrated processing is realized by virtue of single machines for turning, milling, honing and grinding, so that the high-precision multifunctional intelligent machine tool is a combined, high-precision, high-efficiency and intelligent machine tool and can be used for improving the processing process and the production level and achieving the purposes of saving time and saving energy.

Wear Estimation Using 3D Surface Roughness Parameters

Abstract: The aim of this work is to propose a methodology of lifetime prediction of details by new approach for linear wear intensity determination using 3D surface roughness parameters. For qualitative evaluation of the wear process the linear wear intensity (Ih), which may be determined separately for the plastic and elastic contact, is commonly used. Since the elastic contact is mainly required in pairs of details in mechanical engineering in these paper this kind of contact was examined. In our research, the random surface model was used. The surface machined with abrasive instruments (grinding, polishing, honing, etc) has the irregular shape of surface roughness, which can be described with random function. Irregular surface is expressed by a random field h(x, y) of two variables x and y which are Cartesian coordinates of a surfaces point, where the height of roughness asperity h(x, y) has a normal probability distribution. In wear research the probability theory was used. Further in deformed volume calculation, as well as in determination of the length of the surface’s contact the 3D surface roughness parameters were used. The strong correlation between 3D roughness parameters Sa (arithmetic mean height) and Str=Rsm1/Rsm2 (texture aspect ratio of the surface) was revealed. As a result of research, the methodology of lifetime prediction of details by new approach for linear wear intensity determination using 3D surface roughness parameters was elaborated and proposed. After calculation of linear wear intensity Ih, it is possible to estimate lifetime of wearing details. So, at a first time in wear estimation the 3D surface roughness parameters were used. The results of this work have wide practical application, for example in design, texture specification on drawings etc.

Tool for honing connecting bolt hole

Abstract: The invention provides a tool for honing a connecting bolt hole, comprising a honing head and a rotating shaft One end of the rotating shaft is connected with a rotating driving device, and the other end is connected with the honing head; the outer peripheral surface of the honing head corresponds to the wall of the bolt hole; the honing head comprises a telescopic sleeve, a linear motion guide device of the telescopic sleeve, a shaft end sleeve, a honing strip and a hinge rod; the shaft end sleeve is sleeved on the tail end of the rotating shaft and rotates along with the rotating shaft; the hinge rod is formed by hinging two rod together; the joint of the two rods is hinged with the honing strip; two ends of the hinge rod are hinged with the telescopic sleeve and the shaft end sleeve respectively; and the linear motion guide device of the telescopic sleeve and the rotating shaft are arranged coaxially The tool is used for honing and repairing the connecting bolt hole in a certain range and can guarantee the roughness and accuracy requirements of the large connecting bolt hole When the tool works, the tool does not need to be adjusted manually, thereby being convenient to use The tool is simple in structure and easy to manufacture, is safe and reliable and can be applied and popularized widely to various occasions

Experimental investigation of precision finishing of spur gears by pulse electrochemical honing (PECH) process

Abstract: This paper is an aim to present the precision finishing of spur gears by pulse electrochemical honing (PECH) process to study the effects of finishing time, electrolyte-related parameters (electrolyte temperature, electrolyte composition), pulse-on time (Ton) and pulse-off time (Toff) on measure of process performances, i.e., percentage improvement in average surface roughness value (PIRa) and maximum surface roughness value (PIRtm). A special type of cathode gear has been designed having the capability of varying the rate of electrolytic dissolution steplessly along the full profile of the work piece gear. Optimum values of process parameters such as finishing time, electrolyte composition, electrolyte temperature, pulse-on time and pulse-off time have been estimated using graphical analysis. Work samples were also analysed before and after the PECH using the optical profiler to visualise the effects of process parameters on gear tooth profile. Key features of developed PECH setup are also highlighted.

Multi-sensors-based condition monitoring for honing of cylinder liners

Abstract: Development of cylinder liner for internal combustion engines is a challenging task and it involves a thorough understanding of interaction between functional requirements of liners, performance of honing process and desired surface characteristics. In the present work, an attempt is made to bring out the relation between performance of honing process and surface characteristics with the condition of the honing tools. Signals from multiple sensors during rough, finish and plateau operations with fresh or worn out tools show a good correlation between honing tool condition and performance measures such as material removal and surface topography. A strange phenomenon of reduced amplitude in power spectrum of vibration signals occurring with worn out tools is explained. On comparing the acoustic emission (AE) signals and the signals obtained from piezoelectric cutting force dynamometer and accelerometer, it is found that the signals obtained from AE sensor show higher sensitivity in terms of performance measures. A tool condition monitoring strategy which considers all three sensors including AE sensor is proposed in this paper. Such a strategy would help in the timely replacement of the honing tools, thereby enhancing the productivity.

Deep-hole honing head driven by hydraulic motor

Abstract: The utility model provides a deep-hole honing head driven by a hydraulic motor, wherein a hollow spindle is driven by a hydraulic motor equipped with a hollow shaft. A plurality of emery stick frames are inserted into the long grooves of a spindle disc. The plungers of a loop of plunger cylinders on the spindle are pressed against the back sides of the emery stick frame so as to realize the expansion feeding. Oil ports at the bottoms of the plunger cylinders are communicated with the bore of the hollow spindle so as to stretch a spring and return the emery stick frames. An oil supply pipe passing through the center hole of the hydraulic motor is inserted into the center hole of the spindle for supplying oil to the plunger cylinders. When the honing head is in use, a honing rod is only in a linear reciprocating movement without being rotated. The vibration will not happen even if the honing rod is bent or sagged. Therefore, the honing precision of a large-diameter long bore is improved and the driving power of the honing rod is also lowered. Meanwhile, the corresponding mechanism is relatively simple in structure and small in size. The honing head is used for the horizontal honing of large-diameter deep holes, wherein the significant technical and economic effect is realized.

Piston Ring Load Carrying Capacity: Influence of Cross-Hatching Parameters

Abstract: Energy and environment are of major concern in internal combustion engine component design. The piston ring-cylinder liner (PRCL) contact plays an essential part in design and is highlighted in this study. In fact, the rings ensure the sealing property, reducing the environmental impact by avoiding lubricant contamination (blow-by) and lubricant consumption. Unfortunately, when sealing, the rings generate between 11 to 24% of the friction losses in an internal combustion engine [1], thus reducing the energy efficiency of the engine.The cylinder liner surface features a special micro-geometry, a classical one is the cross-hatching pattern, obtained by honing. This texturing acts as a micro-bearing, oil reservoir and debris trap. Understanding the influence of texture parameters as groove depth and width or angle, will allow tribological improvements of the PRCL contact.The 2D transient Reynolds equation has to be solved for this kind of surface. The statistical method using the Patir and Cheng [2] flow factors is widely used. This approach lumps the different components of the surface (grooves and plateaux) and does not consider the roughness directionality. Methods decoupling both components, like the homogenization method [3] are also used. Another alternative is to use a deterministic model on measured surfaces, but this is a “hugely” expensive approach. Multigrid methods [4] are used to drastically reduce the calculational cost.The aim of the current study is to facilitate the understanding of measured surface calculations. Hence, analytical surfaces are used. They allow a flexible handling of the cross-hatching parameters. The plateaux are perfectly smooth and the grooves are sinusoidally shaped. The top ring is modelled using a parabolic profile. Periodic boundary conditions are used in the orthoradial direction and zero pressure conditions (Dirichlet) in the axial direction.To investigate the effect of different parameters, various imposed film thicknesses are applied and the mean load carrying capacity (LCC) over time is calculated. When representing the LCC corresponding to each parameter compared to the smooth LCC, as a function of the logarithm of the minimum film thickness, the curves are quite linear for small values of the film thickness and then for larger values they converge to 1.Copyright © 2012 by ASME

Radial vibration ultrasound honing device

Abstract: The invention discloses a radial vibration ultrasound honing device, belongs to the technical field of ultrasound honing and provides a radial vibration ultrasound honing device for ensuring that an oilstone edge performs radial vibration along a processed hole. In order to solve the technical problem, the technical scheme adopted by the invention is as follows: a main shaft is a hollow stepped shaft with a thicker middle and two thinner ends; a post rod, a transducer, an amplitude transformer and an expanded core shaft are all positioned in the main shaft, and the transducer is provided with an axial through hole; the post rod is positioned in the through hole, the bottom of the transducer and the top of the amplitude transformer are fixed together, and the amplitude transformer is provided with a flange; the bottom of the flange and one of a spring are fixed, the other end of the spring is fixed on a step of the interior hole of the main shaft, and the lower end of the amplitude transformer is connected with the upper end of the expanded core shaft through a thread; and multiple oilstone bases are arranged on a slotted hole through a top foot, and each oilstone base is fixedly provided with an oilstone. The radial vibration ultrasound honing device provided by the invention can be widely used for finishing or finish machining of holes of different shapes.

Honing system for honing of machining center, particularly machine tool for automated operation for complete machining of components, has tool head that has drive unit for actuating adjustment mechanism

Abstract: The honing system (20) has a tool head (24) rotatable around a rotational axis (36) and having an interface for detachable fixing at a rotating driven machine spindle (12) of a machine tool and a honing tool (26) whose honledges are adjustable over a tool-sided adjustment mechanism (42) transverse to the rotational axis. The tool head has a drive unit for actuating the adjustment mechanism. The drive unit is provided with a servomotor. The adjustment mechanism has a pressure-pull-rod (72) linearly movable in the direction of the rotational axis.

Manufacturing method of large-scale reciprocating type refrigeration compressor

Abstract: The invention discloses a manufacturing method of a large-scale reciprocating type refrigeration compressor, which mainly comprises the following steps of: (1) sorting: selecting appropriate casting iron; (2) casting; (3) milling and rough machining an upper face and a lower face; (4) rough machining three holes and the faces; (5) milling and fine machining the upper face and the lower face; (6) fine machining the three holes and the faces; (7) boring an air cylinder hole; (8) drilling and tapping a cylinder body face, an end cover face and a motor cavity face; (9) honing the surface of the air cylinder hole; (10) plasma quenching the surface of the air cylinder hole; and (11) honing the surface of the air cylinder hole again. The manufacturing method of the large-scale reciprocating type refrigeration compressor has the advantages that the accuracy of a product can be effectively improved; and the hardness of the surface of the air cylinder hole of the product can be improved in a double mode.

Method for producing a cylinder liner surface and cylinder liner

Abstract: A method for producing a cylinder liner surface for a cylinder crankcase of an internal combustion engine has the following method steps: (a) preliminary honing of the inner surface of a cylinder liner consisting of a cast iron material to form depressions in the surface; (b) application of a coating material containing zinc to the honed surface; (c) final honing of the coated surface in such a way that the coating material containing zinc remains only in the depressions formed by the preliminary honing.

Device and method for machining of green compact

Abstract: PROBLEM TO BE SOLVED: To provide a device and method for machining of a green compact, capable of preventing the generation of edge chipping generated in the green compact during boring machining by green machining to the utmost, and capable of achieving the reduction in manufacturing cost of a mechanical component.SOLUTION: This machining device 101 includes a columnar cutting edge part 102 at a front end side thereof. Cutting edges 131, 131 are formed at the front end side of the cutting edge part 102. The front end side of the cutting edge part 102 is formed in a taper surface having a diameter expanding from the front end side to a rear end side and having a predetermined tip angle θ. The taper surface has a front end shape formed sharply without applying honing, and the tip angle θ is formed so as to be ≥50° and ≤90°. In the machining device 101, during boring machining of the green compact W, the cutting feed is set to ≤0.05 [mm/rev] when a rear end side end part of the taper surface passes through a "through-edge region w3" of the green compact W.

Experimental characterization of hydrodynamic nanopolishing of flat steel plates

Abstract: Nanoscale polishing finds applications in medical, industrial, telecommunication, optics, electronic and military fields. Typically, rigid tool-based methods such as diamond turning, grinding and honing are employed for nanoscale polishing. These methods have inherent limitations in creating nanopolished surfaces on hard and profiled surfaces. To address the issue, this work is focused on experimental investigation of hydrodynamic polishing (HDP) as a nanopolishing method. The soft rubber tool and the workpiece are submerged in a slurry during hydrodynamic nanopolishing. An elastohydrodynamic film is formed between the tool and the workpiece due to the tool rotation which is responsible for nanopolishing. A HDP experimental setup was fabricated and experiments were conducted on oil hardened and non-shrinking steel (OHNS, 58-62 HRC) with colloidal alumina suspensions of different particle sizes. The experiments were designed using Taguchi techniques to study the effect of four main factors (contact load, tool stiffness, spindle speed and abrasive particle size) and three important two-factor interactions at four different polishing times. Statistical analysis of the results shows that concentration of abrasive in the slurry is a significant factor in the hydrodynamic polishing. The best surface finish of 3.5 nm was obtained using 1 μm abrasive particle size colloidal suspension at 7.5 N load, 2400 rpm spindle speed, 90 shore A tool stiffness and 3 min of polishing time. The change in surface morphology and topography due to polishing also confirm the efficacy of the HDP process.

Numerical control twisting and honing machine tool used for processing precise round hole

Abstract: The utility model discloses a numerical control twisting and honing machine tool used for processing a precise round hole. The numerical control twisting and honing machine tool used for the processing precise round hole includes a rack. The rack is provided with a rotating table, a cutter shaft box, cutter shafts arranged in the cutter shaft box and a control and programming system. The cutter shafts are driven by a main motor for gyroscopic motion. The cutter shaft box is driven by a numerical control motor and a screw rod for up-and-down reciprocating motion on a guide rail of the machine tool. A to-be-processed work piece is installed in a floating clamp on the rotary table driven by the motor and capable of rotary indexing. The corresponding cutter shafts of the cutter shaft box are equipped with twisting and honing cutters having cutter rods equipped with profiling opening profiling sleeves coated with corundum micro powder grinding material. The technical scheme solves problems of high labor strength, low production efficiency, dispersed working procedures, large fluctuation of processing quality and poor geometric processing accuracy that can not satisfy processing accuracy indexes in a traditional grinding technique. At the same time, problems of low processing accuracy, high aperture dispersion degree, dispersed working procedures and difficult realization of multiple spindles and multiple stations in honing technique are solved. The numerical control twisting and honing machine tool used for the processing precise round hole provided by the utility model utilizes scientific processing principles and has a reasonable cutter structure. At the same time, the numerical control twisting and honing machine tool used for the processing precise round hole can be used in combination with a specially designed multi-spindle multi-station numerical control twisting and honing machine tool, thereby satisfying accuracy qualification requirements of processing the precise cylindrical hole.

Method for combined fine boring and honing machining, and machining plant for executing the method

Abstract: A method for fine boring of internal surfaces of bore holes in work pieces as well as a machining plant for executing this method. The fine machining, fine boring, and honing include fine boring of a bore hole of a work piece using a fine boring tool; transferring the work piece into a honing device; measuring the fine bored bore hole with a measuring device associated with the honing device; and controlling the operation of the fine boring device depending on the bore hole measuring signal received by the measuring device. An output fine boring machining, arranged directly upstream of the transfer, is dimensioned as semi-finishing machining, and is carried out with a fine boring tool having at least one adjustable cutting edge. The position of the adjustable cutting edge is controlled depending on the bore hole measuring signal.