Showing papers on "Honing published in 2015"

Roughness variations in cylinder liners induced by honing tools’ wear

Abstract: The manufacturing and finishing (honing) of cylinder liners for the automotive industry is a constant challenge in order to reduce friction losses and oil consumption. A better knowledge of surface ...

Characterization of surface textures generated on hardened steel parts in high-precision machining operations

Abstract: This paper presents the comparison of surface textures produced by high-precision cutting and abrasive processes on hardened steel parts. Investigations include surfaces generated by hard turning, belt grinding, and superfinishing (external honing) operations. As a result, several surfaces generated with different process kinematics and the Sa roughness parameter of about 0.05 μm were compared. Apart from the standard 2D and 3D roughness parameters, the fractal, motif, and frequency parameters were considered.

Machining process and tool for shaft with inner step hole with large depth-diameter ratio

Abstract: The invention provides a machining process and tool for a shaft with an inner step hole with a large depth-diameter ratio. The process includes the steps of preparing a workpiece blank first, drilling a middle hole, finely boring the middle hole, honing the middle hole, boring on a large hole in a push mode, drilling a small hole, conducting rotary swaging shaping, machining the outer circle, and finally drawing out a combined core shaft, wherein the combined core shaft is formed by connecting a large-end core shaft, a middle core shaft and a small-end core shaft through threads. Through the machining process and tool, hole drilling straightness is improved remarkably, the reject rate is reduced, and meanwhile mechanical properties of a workpiece are enhanced.

Process Performance Comparison of ECH and PECH for Quality Enhancement of Bevel Gears

Abstract: This paper presents a comparative analysis of constant-current electrochemical honing (ECH) and pulsed electrochemical honing (PECH) for quality enhancement of straight bevel gears. The quality of straight bevel gears after finishing by ECH and PECH is compared focusing on tooth flank finish and microgeometry. Tooth flank finish was evaluated in terms of percentage enhancement in average roughness value, maximum roughness value, and 5-point roughness value. Percentage enhancements in pitch error, pitch variation error, accumulated pitch error, and total runout were used to evaluate the microgeometry of the bevel gears. It was found that the PECH process is capable of simultaneously enhancing the tooth flank finish and microgeometry of bevel gears by more than 50% as compared with ECH-finished bevel gears. The PECH-finished gears also exhibited superior microstructure as compared with ECH-finished gears. These improvements will enhance the service life and working performance of gears.

Mixed ultra-hard abrasive honing stone

Abstract: The invention discloses a mixed ultra-hard abrasive honing stone. The mixed ultra-hard abrasive honing stone is characterized by comprising the following components in percentage by weight: 20-40 percent of copper, 2-6 percent of silver, 1-10 percent of aluminum, 2-6 percent of zinc, 2-20 percent of tin, 10-20 percent of iron, 5-10 percent of nickel, 5-30 percent of cobalt, 1-9 percent of lead, 5-10 percent of a bonding agent and the balance of an ultra-hard material, wherein the volume ratio is 60-100 percent; the metal purity of the copper, the silver, the aluminum, the zinc, the tin, the iron, the nickel, the cobalt and the lead is over 99 percent; the granularity of the ultra-hard material is 200-1,000 meshes; the honing stone is prepared by performing mixing, cold press molding and vacuum hot press process on the raw materials according to the mixture ratio. The mixed ultra-hard abrasive honing stone disclosed by the invention has the advantages of sharp grinding, high grinding efficiency, large grinding weight, short grinding time, long service life, superior self-sharpening property, low process cost, easiness and convenience in preparation, and the like.

A comparative study of precision finishing of rebuild engine valve faces using micro-grinding and ECH

Abstract: This paper presents a comparative analysis of process performance of micro-grinding and electrochemical honing, with the aim to achieve higher precision and surface quality of rebuild surfaces of the engine valve face. The discarded engine valve face was rebuilt using plasma transferred arc cladding technique and its surface finish was evaluated in terms of average roughness and maximum roughness value. The improvement in profile error and total run-out were used to evaluate the optimum processing time of micro-grinding and ECH. The sets of experiments for micro-grinding and ECH were conducted. The results reveal that the ECH process is one of the ideal choice for finishing of recovered surfaces. The surface morphology of the processed part is significantly improved resulting in glazed and uniform texture. Results show that the ECH can produce the workpiece surface 75 % efficient than the micro-grinding. A significant improvement of 23.37 % in the average surface roughness value was found after ECH as compared with the micro-grinding.

Lead Crowning and Anti-Twist for Tooth Flank of a Heat Treated Helical Gear on Internal CNC Honing Machine

Abstract: The internal gear honing is more popular than the external gear honing by its advantages such as higher contact surface and easier correct profile errors. It is usually applied for modifying the gear surface to compensate for the distortions after heat treatment process. However, the lead crowning and anti-twist tooth flank of a helical gear on internal CNC gear honing has not studied yet. Therefore, a novel method for lead crowning tooth flank of work gear surfaces is proposed by using a linear swivel angle function of the honing wheel and a variable pressure angle (VPA) honing wheel is also applied for anti-twist of the crowned tooth flank in honing process.

Machining and Machining Modeling of Metal Matrix Composites—A Review

Abstract: This chapter reviews the most common machining processes used in metal matrix composites (MMCs), such as turning, milling, and drilling. Apart from the difficulties faced in each of these processes in the case of MMCs and some possible solutions, certain other important factors, such as tool wear mechanisms and the final surface quality, are discussed. Furthermore, the machinability of MMCs, in a number of different machining processes, is examined. Tapping, grinding, honing, sawing, and micro-machining are also considered. Additionally, the manufacturing of MMC products through nonconventional machining processes is discussed, as alternatives to the aforementioned processes. Finally, modeling of MMCs and their machining will be examined. The analysis will concentrate on the most popular methods used, namely finite elements method, molecular dynamics, and soft computing techniques.

Methodology of a computer aided design of shrink fit taking into account roughness and form defects of manufacturing process

Abstract: The assembly technique of interference fit (shrink fit) is increasingly used today. However, the design methodologies for these assemblies use older models based on very restrictive assumptions about the shape and the surface quality of assembled parts. FEM software are now often used to overcome these drawbacks. They allow an approach closer to the physical reality of the parts (complex form). However, the surfaces are generally considered to be perfect cylinders and the tightening, constant. The proposed approach makes it possible to introduce, in the design, both form defects and roughness, thus taking into account the manufacturing process. For this, form defect is integrated directly in the mesh while roughness is taken into account by an homogenized finite element of interface. An example of an application to determine specifications which take the manufacturing process (honing, grinding, turning, etc.) into account is presented. This simple method can be easily applied in industrial design offices.

Honing with polymer based cutting fluids

Abstract: It is currently not possible to omit cutting fluid in honing processes due to the relatively low cutting speeds and the planar contact between workpiece and honing stone and the therefore needed flushing capability for chip removal. Resource efficiency can be maximized during the honing process by replacing mineral oil based honing oil with an alternative fluid. In this study grey cast iron was honed under the application of honing oil and mineral oil free cutting fluid, henceforth referred to as polymer dilution. The obtained results showed that the polymer dilution leads to higher achievable specific material removal rates with concurrently lower surface roughness compared to the application of mineral based honing oil.

Effect of finishing time and electrolyte composition on geometric accuracy and surface finish of straight bevel gears in ECH process

Abstract: This paper presents study on the effects of electrolyte composition and finishing time on geometric accuracy and surface finish of straight bevel gears by electrochemical honing (ECH) process with an objective to improve their service life and operating performance. An experimental setup was developed for fine finishing of straight bevel gears by ECH using an innovative concept of twin complementary cathode gears. It ensured finishing the entire face width of the bevel gears without any reciprocating motion and maintained the required inter-electrode gap (IEG). Gravimetric aqueous solution of NaCl and NaNO 3 was used as the electrolyte. Geometric accuracy was evaluated in terms of errors in pitch and runout while surface finish was evaluated by average and maximum surface roughness values. An electrolyte composition having 75% NaNO 3 and 25% NaCl and finishing time of 2 min were found as the optimum combination. The results have shown considerable improvement in geometric accuracy and surface finish of the bevel gears. It proves the capability of ECH to improve the quality of the bevel gears of any material hardness with high productivity.

Method for arranging stainless steel sleeve in large-diameter cylinder block in sleeving way

Abstract: The invention discloses a method for arranging a stainless steel sleeve in a large-diameter cylinder block in a sleeving way. The method comprises the following steps: firstly, performing boring machining on the inner wall of the cylinder block, manufacturing the stainless steel sleeve according to the size of the machined inner wall of the cylinder block, and machining a triangular thread on the inner wall of the cylinder block; secondly, arranging the stainless steel sleeve in the cylinder body in a sleeving way at the normal temperature, performing hot rolling on the stainless steel sleeve while heating, cooling to the normal temperature after the completion of hot rolling, and performing cold rolling on the stainless steel sleeve at the normal temperature; lastly, honing the inner wall of the stainless steel sleeve by using a honing head. The process is simple, the adhesion between the stainless steel sleeve and the inner wall of the cylinder block is high, and the inner wall of the stainless steel sleeve can meet the requirements of smooth finish and size.

Gear machining and treating process

Abstract: The invention relates to a gear machining and treating process The gear machining and treating process includes the steps that blanking and blank manufacturing are carried out; a gear blank is machined; rough machining and semi-finish machining of a tooth form are conducted, ie, according to a precision requirement, tooth grooves are cut in the whole blank and a corresponding allowance for finish machining is reserved on the groove side at the same; the gear end is chamfered and burrs are removed; heat treatment is carried out; tooth form machining is carried out on an unfinished product subjected to heat treatment by adopting the method of gear grinding or gear honing or gear lapping again; strengthened shot peening is carried out so as to improve the endurance bending strength and contact fatigue strength of a gear; and cleaning is carried out Through the gear machining and treating process, the content of retained austenite on the surface of the gear and the thickness of a non-martensite layer on the surface of the gear are reduced; by the adoption of the high-temperature carbon potential changing method, production efficiency is improved; thus, the tissue performance of the tissue surface is greatly improved, and the phenomenon of tooth breakage cannot occur

A Physics-Based Predictive Model for Number of Contact Grains and Grain Depth of Cut in Honing

Abstract: Honing is a material removal process widely used in manufacturing of engine cylinders, compressors, valves, bearings, and hydraulic cylinders. The surface topography generated by honing has a profo...

A Methodology for Longitudinal Tooth Flank Crowning of the Helical Gear on a CNC Honing Machine

Abstract: The gear honing is the most economical way for hard finishing an involute helical gear after hobbing and heat treatment or after shaving and heat treatment. The gear honing can also be applied to the modification of gear tooth surfaces to compensate for the distortions that occur during heat treatment process. Most published papers on the technology of gear honing describes on the principle of generated gear surface. However, the longitudinal tooth flank crowning of a helical gear with honing has not been investigated yet. Therefore, in this paper, we proposed a novel method for longitudinal tooth flank crowning of work gear surfaces by setting a crossed angle between the honing cutter and work gear axes as a linear function of honing cutter's traverse feed in the honing process. A mathematical model for the tooth profile of work gear honed by a standard honing cutter is also established. Three numeral examples are presented to illustrate and verify the merits of the proposed gear honing method in longitudinal crowning.

Manufacturing method for high-precision cold-drawing welded pipe

Abstract: The invention relates to a manufacturing method for high-precision cold-drawing welded pipe. The manufacturing method for the high-precision cold-drawing welded pipe includes steps of longitudinal shearing, roll-bending forming, high-frequency welding, weld joint treatment, sizing, online eddy current inspection, pre-straightening treatment, pipe cutting, stress relief annealing, pinching, acid dipping, phosphating, saponification treatment, cold drawing, induction furnace quenching treatment, tempering treatment in a box type furnace, straightening treatment, honing, magnetic leakage detection and pipe cutting measurement. The product obtained through the manufacturing method for the high-precision cold-drawing welded pipe is high in yield strength, high in tensile strength, precise in size, smooth in surface, fast in processing forming speed and high in yield, the manufacturing precision is obviously improved, the cold-drawn welded pipe is good in surface smoothness and low in roughness, the subsequent gold processing amount is reduced, the steel material use ratio is improved, the manufacturing cost is lowered, and the energy conservation and environment protection are boosted.

Machining technology of cylinder barrel of steering oil cylinder

Abstract: The invention discloses a machining technology of a cylinder barrel of a steering oil cylinder and belongs to the field of hydraulic oil cylinders. The machining technology comprises the main steps that of (1) blanking, (2) turning, (3) support welding, (4) milling, (5) drilling, (6) machining of an inner hole and (7) forming of a semi-finished product. In the step of support welding, the mode of semi-automatic welding with protection is adopted, the working efficiency and the machining precision are improved, and welding is safer. The step of inner hole turning and the step of honing are combined through a deep hole boring machine, inner hole turning and honing are conducted at the same time, the surface smoothness and the surface hardness of the inner hole are improved, and the errors of the inner diameter are reduced; besides, the procedure is simplified, and efficiency is improved.

Inner hole honing equipment for master cylinder of hydraulic machine

Abstract: The invention discloses inner hole honing equipment for a master cylinder of a hydraulic machine, and the equipment comprises a spindle motor, a spindle, an oil pump motor, a small cutting feed cylinder, a grinding head, an oilstone, left and right movement connectors, left and right movement cylinders, a workpiece fixing bracket and a workpiece fixing pedestal; the spindle motor is connected with the spindle, the oil pump motor is connected with the small cutting feed cylinder, the small cutting feed cylinder is connected with the spindle, the workpiece fixing bracket is composed of two plates to clamp the outer wall of the main cylinder, and the workpiece fixing bracket is arranged on the sliding device of the workpiece fixing pedestal and can be moved along the sliding device. The left and right movement connectors and the left and right movement cylinders are used to control the horizontal position of the workpiece fixing pedestal. In the inner hole honing equipment, the oilstone can swell and shrink through the small cutting feed cylinder, the grinding head and the oilstone, and the oil cylinder is fixed and adjusted by the workpiece fixing bracket. The inner hole honing equipment is easy to operate and adjust in the whole process.

Experimental Study of Effective Parameters on Honing Process of Cast Iron Cylinder

Abstract: Honing is a process for finishing surfaces to obtai n smooth surface. This process is used for final polish of inner parts such as engines cylinders. Op timizing this process has always been a big challenge for mass production of cylinder blocks of internal combustion engines. Honing process has some variable parameters, thus to get their opt imum rates the automobile cylinders were tested. In this research, experiment design was done using Taguchi method and to make input constant parameters of the test consistence, cylinder was bo red using boring machine and in the next phase, cylinder was honed according to the design of exper iment. Abrasive particles were selected from the material of carbide silicone stone and the vari able parameters considered in this test were tangential speed, grain size, and the number of too ls course. In order to measure surface quality of each cylinder, roughness tester machine was used an d surface quality considered as output parameters of machining. Then, the results of the t est were studied and analyzed on software environment . According to the tests conducted, the optimum valu es of mesh stone of honing and optimum values of numbers related to the course number and rotation were identified on the best state.

Cylinder liner and method of forming the same

Abstract: A high strength cast iron material for application in heavy duty diesel engines with Pa peak cylinder pressure greater than 240 bar is disclosed, the material a ductile material austempered to get a ausferrite matrix structure with higher mechanical properties than conventional cast iron materials available by using a designed low cost alloying cast material with heat treatment. Furthermore, the cylinder liner may be formed using novel heat treatment and/or fine honing processes to improve the properties thereof.

Graded Freeform Machining of Cylinder Bores using Form Honing

Abstract: The use of form honing contributes to energy efficiency of modern internal combustion engines, especially to the reduction of CO2. Until now the production of internal combustion engines has required cylindrical bores with high shape and surface quality. This machined macro form is not maintained for the function of the engine due to mechanical and thermal influences. During operation they cause complex distortion mechanisms which significantly deviate from the desired cylinder form. Therefore Gehring developed a form honing process that does not produce the cylindrical bore form as its goal, but gives instead the expected cylindrical deformations having the quasi cylindrical bore geometries under specific operational conditions. Furthermore the current development of form honing considers the friction of the piston skirt of the cylinder operation temperature with specific clearance in the lower part of the bore. This is possible without impairment of the NVH behavior of the engine. The freeform for compensation of cylinder distortions and the local clearance for reducing friction at the piston skirt, can be applied in a complex form or used separately. Correlating to the high degree of freedom of form honing, all the functional advantages of freeform of cylinders bores can be achieved. The principle of form honing, the process components, the serial production capability, the increased quality concepts and the achieved machining and functional results are described below. Consequently, form honing is an innovative contributor to the sustainability of the internal combustion engine. This paper describes the production process, which is available for the serial production of internal combustion engines. The test results of the fired engines are not the knowledge of Gehring Technologies GmbH. Non Cylindrical Bore Shapes Distortions of cylinder bores occur depending on static assembly deformations, dynamic forces and mostly by thermal influences. To obtain a quasi cylindrical bore at relevant operation points. These distortions will be pre compensated by form honing of non cylindrical macro shapes. Depending on the stiffness of the crank case and on the heat input local radial shape deviations of 10 μm to 40 μm can be generated. Due to the limited shape filling capacity of the piston rings only an incomplete geometrical approximation to the distortion of the cylinder bore is possible. By local different contact of piston rings the blow by and oil consumption increased. Also the non cylindrical shape contains overlaid bottleneck contours in the lower part of the bore which reduces the contact of the piston skirt. Compensation of Cylinder Distortions To fulfill the functional requirements of the cylinder bore, a honing process was developed to compensate of functional bore distortions. This means that the machining process allows to pre compensated the final functional deformations. Under defined fired conditions the non cylindrical bore will be deformed to an extensive cylindrical shape. This allows a reduction of piston ring tension and thus a fuel saving friction reduction. Figure 1 shows the principal solution for compensation of bore distortions. Figure 1. Free shape solution of compensation of cylinder distortion Local Optimization of Piston Clearance A further improvement of the tribological system piston/cylinder bore is based on the high part of friction of the piston skirt and third piston ring of 46 % compared with the part of friction of the first and second piston ring of 34 %. The remaining 20 % friction losses are generated in the conrod bearing [1]. The optimization of piston skirt clearance Graded Freeform Machining of Cylinder Bores using Form Honing 2015-01-1725 Published 04/14/2015 Gerhard Konrad Flores Gehring CITATION: Flores, G., "Graded Freeform Machining of Cylinder Bores using Form Honing," SAE Technical Paper 2015-01-1725, 2015, doi:10.4271/2015-01-1725. Copyright © 2015 SAE International Downloaded from SAE International by Gerhard Flores, Monday, April 27, 2015