Papers by Keyword: Quick-Point Grinding

Abstract: Through grinding experiment on mica glass ceramic, the mechanism of material removal was analysed, the fracture and removal of engineering ceramics was suitable for Griffiths fracture strength theory. And the factors of affected surface roughness were studied. The results indicated, The surface roughness was significantly affected by the grinding depth, inclining angle and deflecting angle in quick-point grinding engineer ceramics. The surface roughness value decreased with increasing of the wheel velocity, increased with increasing of the workpiece feed, decreased with increasing of grinding depth, increased with increasing of grinding wheel inclining angle and decreased with increasing of grinding wheel deflecting angle.

Abstract: Quick-point grinding technology, suitable to be applied in automobile manufacturing, cemented carbide and ceramic material processing industry, was an advanced ultra-high-speed grinding technology. It is the integration of super-high speed grinding, CBN super-abrasive and CNC flexible manufacturing and so on. The characteristics of quick-point grinding were systematically illustrated. Applications of this technology to process hard-machining materials and shaft parts were also given in this paper. Some problems and solutions corresponding to quick-point grinding technology were presented finally.

Abstract: Abrasive machining is a widely employed finishing process for different-to-cut materials such as metals, ceramics, glass, rocks, etc to achieve close tolerances and good dimensional accuracy and surface integrity. High speed and super-high speed abrasive machining technologies are newest developed advanced machining processes to satisfy super-hardness and difficult-to-machining materials machined. In the present paper, high-speed/super-high speed abrasive machining technologies relate to ultra high speed grinding, quick-point grinding, high efficiency deep-cut grinding were analyzed. The efficiency and parameters range of these abrasive machining processes were compared. The key technologies and the newest development and current states of high speed and super-high speed abrasive machining were investigated. It is concluded that high speed and super-high speed abrasive machining are a promising technology in the future.

Abstract: A study on the wear of Quick-point grinding wheel was carried on. The wheel wear was found having great influence on grinding performance and grinding quality. After analyzed the wear process and mechanism in Quick-point grinding, it was found the wear rate was directly related to some factors such as wheel width, workpiece speed, feed rate and Quick-point grinding angle, and it was indirectly affected by wheel speed and cutting depth. By means of some wear criteria, the wheel wear was able to be predicted. Furthermore, a wear model in wheel’s accurate area has been built up.

Abstract: It is important that preparing high quality grinding wheel to match Quick-point grinding processing. Using brazed CBN grinding wheel, grains can be combined with wheel matrix in high bonding strength, which is helpful to minimize wheel wear and to gain a good grinding ability. By establishing the connection between stress and its increment, the mechanical properties of wheel under different conditions is described. The wheel speed has effect on wheel matrix displacement and stress. Applying finite element method to optimize wheel structure, a final grinding wheel for Quick-point grinding is obtained.

Abstract: Separating the workpiece velocity on the plane of grinding wheel, it is helpful to analyze Quick-point grinding mechanism. There are some relations among wheel’s deflective angle, workpiece feed velocity and tangential velocity. In this research, the resultant workpiece speed, grinding contact zone and material removal mode is analyzed. And a model is established which is helpful to analyze the tendency of component grinding forces and force ratio. It is found the grinding force is influenced by the factors such as cutting depth, wheel velocity, grinding angle as well as equivalent diameter, respectively. Finally, a theoretical basis for actual processing is provided.

Abstract: Quick-point grinding is more advanced and more efficiency as a method of high and super-high speed grinding. Its main grinding properties are low grinding forces and temperature. Its basic characteristic is the axis of wheel and workpiece are not parallel and not contained by the same plane. That makes the geometrical property of the quick-point grinding different from conventional cylindrical grinding. This paper emphasizes particularly on the abrasive geometry analysis on the quick-point grinding. After founding a model, this paper has educed equivalent wheel diameter, maximum contact length, undeformed chip thickness and so on. In this paper the quick-point-grinding angle is made use of to find a model of grinding force and deduce an expressions.

Abstract: Due to the high grinding speed and the less contact length, there is the super high material strain rate in the contact layer during quick-point grinding process. Based on the principle of micro-damages mechanics, it is the impact process between the workpiece and the grits on the wheel in the process. The weakening effects of the super high strain rate caused by the mechanical impact micro-damages and the adiabatic shearing damage can lower the dynamic strength of the material in contact layer and the micro-plastic pile-up deformation on the ground surface in the process. Therefore, it is possible to improve the surface integrity of the workpiece since the materials removal mechanism is changed in quick-point grinding process. In this paper, the impact performances and the model of quick point grinding process were studied. Based on the above, the model of the ground surface roughness related to the plastic pile-up deformation was established. The effects of the strain rate on the ground surface roughness and the materials removal ratio were analyzed. In addition, the grinding experiment was performed to testify such investigations. It is indicated that quick-point grinding is an impact process assuredly during the removing material process.

Abstract: In this paper, grinding performance and Manufacturing process of vitrified CBN wheel were described for Quick-point grinding at 200m/s. In order to insure security rotation of wheel, wheel core was optimized at 200m/s based on ANSYS software. Four kinds of domestic abrasives were tested for their compressive strength, impact toughness, microcosmic crystal photographs, and oxidation temperature, high temperature performance baked at 870 °C, by right of advanced apparatus such as SEM etc. Simultaneity vitrified bonds, wheel segments and adhesive techniques were also discussed. At last, grinding performance of Quick-point Grinding wheel was tested.

Abstract: In high and super-high speed grinding process, there is an airflow layer with high speed around the circle edge of the grinding wheel that hinders the grinding fluid into contact layer, namely, the air barrier effect. The speed of airflow layer is directly proportional to the square of the wheel speed. Quick-point grinding is a new type of high and super-high speed grinding process with a point contact zone and less grinding power. The edge effect of the air barrier is weakened because the thin CBN wheel is applied in the process. By the analysis of dynamic pressure and velocity distributions in the airflow layer around the wheel edge, the mathematic models of the flow and jet pressure of grinding fluid for effective supply in the process were established and the process of optimization calculation of the jet nozzle diameter for green manufacturing was also analyzed based on the thermodynamics and the technical character of quick-point grinding process. The quick-point grinding experiment for surface integrity influenced by grinding fluid supply parameters was performed.