الفهرس | Only 14 pages are availabe for public view |
Abstract grinding forces is too Large and the truing operation is needed. This may be done by the measurements of a few parameters such as the RMS of the vibration level, Ra, and q for surface produced. Matrix material has a strong effect on system stability. The surface roughness increase with the increase of the vibration level. The increase of the feed rate cause an increase in the surface roughness. The increase of the depth of cut causes an increase in the roughness. There`s a maximum value for the surface roughness which can be attain with each grinding wheel. Ttuing is an essential part of the grinding process having a profound effect on the mechanism of metal removal and the surface topography of the workpiece. The shape and distribution of the grit in the wheel is function of the truing method. The surface roughness of the workpiece and the vibration level are shown to be a function of the contct area between the tool and workpiece. They are also shown to be a function of number of cutting edges. Grinding is a very complex metal removal since it is random by nature and the fact that randomness is present makes the process difficult to analyse. In precision grinding operations vibration sometimes causes poor workpiece surface quality. It may also limit the production rate by requiring frequent wheel truing therefore increase grinding costs. It is an essential importance to understand the cause of viberation. The machine tool used in this study is a horizontal surface grinding machine. A mathematical model is suggested which relates the grinding-wheel condition and study the forces generated during the grinding interval and their effects on the vibration level. The experiment is conducted to study the behavior of the machine tool during cutting. This experiment relates the vibration of the combination of tool/workpiece interface to the quality of the surface produced. The experiment is extended to a grinding tool with different cutting surface topographies by introducing different truing techniques. The results obtained in the present investigations may be conclude as follows : It is possible to define failure of the surface topography of the wheel ( grindability ); the condition where the wheel surface is too dull and the grinding forces is too Large and the truing operation is needed. This may be done by the measurements of a few parameters such as the RMS of the vibration level, Ra, and q for surface produced. Matrix material has a strong effect on system stability. The surface roughness increase with the increase of the vibration level. The increase of the feed rate cause an increase in the surface roughness. The increase of the depth of cut causes an increase in the roughness. There`s a maximum value for the surface roughness which can be attain with each grinding wheel. Ttuing is an essential part of the grinding process having a profound effect on the mechanism of metal removal and the surface topography of the workpiece. The shape and distribution of the grit in the wheel is function of the truing method. The surface roughness of the workpiece and the vibration level are shown to be a function of the contct area between the tool and workpiece. They are also shown to be a function of number of cutting edges. |