Papers by Keyword: Grinding Wheel

Abstract: In the process of modern mechanical parts production, such as parts surface dust, metal powder, coating will appear "nodules" and "burr", easy to fall off small pit of coating surface. So, to ensure the quality of electroplating products plating, to carry out the study on substrate surface treatment before plating technology of plating is very meaningful.

Abstract: A purely analytical method, based on the meshing theory, is presented to establish the exact helical groove and circumferential cutting edge model of end mills, for the solution of its low design precision and efficiency problems. Firstly, a coordinate system to represent the relative space position relations between grinding wheels and end mills is built and the mathematical model of the helical groove is precisely calculated with a given wheel profile and relative movements between the wheel and the workpiece. Then, the rake angle, inner radius and wheel positions of machining the clearance faces is computed. Finally, a 3D model of the end mill is generated by using OpenGL.

Abstract: Article shows the calculation of the stress in a rotating disc and the possibility of using proprietary forms of instruments for speed grinding. It presents the results of speed and efficient cutting tools in machining these materials alloyed with chromium. In addition, it notes the results of the influence of technological conditions on the quality of surfaces, the residual stress in the workpiece, resulting from the machining speed and the influence of technological conditions on the wear of grinding wheels. Finally, some options for the use of finishing techniques in practice are mentioned.

Abstract: In the grinding operation, grinding wheels are deformed by grinding forces, so that residual stock removal of the workpiece takes place. Since this residual stock removal of the workpiece causes low machining efficiency and deterioration of machining accuracy, high hardness grinding wheels may be selected in order to obtain high machining efficiency and/or high quality machining accuracy. On the other hand, when grinding operations used by low hardness grinding wheels are carried out, it is well known that ground surface roughness is smaller than in case of higher hardness grinding wheels. From such a viewpoint, this study aims to investigate experimentally the effect of the contact stiffness of grinding wheel on the ground surface roughness and the residual stock removal of the workpiece. Grinding operations were carried out using three grinding wheels which are different hardness type, and ground surface roughness and residual stock removal of the workpiece were measured. The contact stiffness of grinding wheel was calculated by a support stiffness of single abrasive grain and a contact area between grinding wheel and workpiece. Comparing the contact stiffness of grinding wheel with the ground surface roughness and the residual stock removal of the workpiece, it was known that ground surface roughness increases and residual stock removal of workpiece decreases with increaseing the contact stiffness of grinding wheel. From these results, since elastic deformation of the grinding wheel changed depending on the suppot stiffness of single abrasive grain, it was clarified that the ground surface roughness and the residual stock removal of the workpiece were changed by the contact stiffness of grinding wheel.

Abstract: As one of the important input parameters in the grinding process, the surface topography characteristic of grinding wheel has a decisive impact on the grinding performance. To evaluate and analyze the microscopic surface topography, the premise must be able to detect the microscopic surface topography accurately. Based on the measurement of detection device and its spatial position, the surface topography detection methods have been classified, the principle has been specifically analyzed for some typical detection methods, and the research work done by domestic and foreign scholars in the area. Finally, the current problems and future research direction in the field have been analyzed.

Abstract: Preparation of superabrasive grinding wheels presents severe challenges due to the high hardness of abrasive grain. In this paper, electrical discharge dressing (EDD) technology with misted emulsion is applied to dressing bronze-bonded diamond wheels. Dressing experiments were carried out. The wheel profiles before and after dressing were measured using a Dektak 6M profilometer. The diamond wheel surface topographies before and after dressing were observed by three-dimension digital microscope. In addition, the performance of EDD’ed wheel was evaluated in practical grinding. It is shown that favorable surface topography can be obtained under suitable processing parameters and EDD misted emulsion with is feasible for metal-bonded diamond grinding wheel.

Abstract: Heat transfer performance of the heat-pipe grinding wheel (HPGW) is mainly depended on the heat pipe in the wheel. In this paper, a basal body of HPGW was developed and a heat transfer experiment was performed to study the effect of the parameters of the heat pipe such as liquid filling ratio and rotating speed on the heat transfer performance of the HPGW. Results show that the heat transfer performance decreases if the liquid filling rate is too large or too small under the same heat source intensity and the optimal liquid filling rate is about 35% of the volume inside the heat pipe. The heat transfer performance of the HPGW is enhanced with the increasing of the rotating speed. The analysis of the results also shows that the heat pipe in the HPGW can play a great role on enhancing the heat transfer in the grinding zone with suitable processing parameters.

Abstract: A polyimide resin-bonded cubic boron nitride (cBN) wheel was designed and manufactured for precision grinding ferrous materials. Firstly, the curing reaction of the resin, which including chain and cross-linking polymerization stages with the exothermic peaks of 140°C and 235°C, respectively, was analyzed by DSC-TG. Based on thermal analysis, a hot press forming process and a post thermal treatment were employed for manufacturing the wheel. Grinding experiment results showed that the transient normal grinding forces vary from 9 to 12 N and fluctuate slightly with 1~2 N when grinding hardened steel 45#. The grinding ratio of 775 and the surface roughness of 0.19 μm were obtained.

Abstract: A phenolic resin-bonded cubic boron nitride (CBN) wheel was designed and manufactured for precision grinding ferrous materials. The resin was determined to be a linear phenolic resin pre-polymer added with hexamethylenetetramine by infrared spectrum and the curing reaction, which characterized by an exothermic peak at about 180°C with release of NH₃, was analyzed by differential scanning calorimeter and thermogravimetry. Based on thermal analysis, a hot press forming process and a post thermal treatment were employed for fabricating the resin-bonded CBN wheel. Grinding experiment results showed that normal grinding forces vary from 7 to 11 N and fluctuate slightly with 1~2 N. The grinding ratio of 585 and the surface roughness of 0.18 μm were obtained under an appropriate grinding condition.

Abstract: According to the multi-body system theory and geometric topology analysis method, combining the geometric structure and working principle of thread NC grinder, made the kinematics analysis for each parts of NC grinder. And the mathematical model for geometric topology structure of grinding machine system was established; the precision machining equations of NC grinder was deduced. Furthermore, the paper used the coordinate transformation principle of homogeneous to deduce the precision processing equation of NC grinder, all of that was based on the moving relationship of the machine tool, the workpiece and the grinding wheel, and got a kind of method that it can use multiple line grinding wheel to grind small radius, small screw pitch and multiple thread. This method laid a theoretical foundation for NC grinder machine processing which used multi-line grinding wheel to grind threads, and improve the grinding efficiency and precision of multi-line grinding wheel; in addition, this method has obtained good effect in grinding thread production.