1
CHAPTER
INTRODUCTION
1.1 Introduction
Grinding is an important process that precise parts with smooth and consistent surface finish. It is utilized in the fabrication of many everyday products, such as bearing
components and is the final machining set in much of today’s precision component
manufacturing. Grinding operations are found in nearly all applications of precision materials production. Leondes. C, 2001.
Grinding is one of the oldest machining processes. Ancient humans became the first grinding engineers when they discovered one could take two rocks and rub them
together in order to form tools and weapons. Grinding engineers now employ the most modern techniques to
remove material to form their products. In today’s global market, there is the ever-daunting task to make the machining process more efficient. Irani
et al
, 2005
An abrasive material removal grinding is one of the oldest machining technologies employed today, and has been utilized by people in manufacturing of parts
since the Stone Age Malkin, 1989. Various research approaches have been undertaken to help eliminate the problems arises in the metal working industry Hekman K.A
et al
, 1997. In 1990, Whitney approaches a force control or power control to minimize the
effects of the machine compliance in robotic deburring.
2 In the area of surface grinding, research has shown that rotating the part, as well
as the grinding wheel or using lapping kinematics which is a combination of rotation and translation improves the surface flatness Matsui
et al
, 1991. Rotating the part causes the variation of path lengths of a grinding wheel grain to be smaller. This creates
a force that has less variation, which results in a flatter surface. Unfortunately, the kinematics of this method does not readily fit with existing machine tool configurations
therefore restricting its applicability. Hekman K.A
et al
,1998
In the area of active control, Jenkins found that adjusting the depth of cut to maintain a constant grinding force produced a flatter surface Jenkins, 1996. This result
works well for workpieces that are initially flat, long and slender. However, in most cases, the partwheel contact geometry is changing, causing the force to change,
assuming a constant depth of cut.
Yoo and Dornfeld used a model of grinding force, to analytically plan a vertical feed trajectory to compensate for the compliance Yoo S. M, 1990. Through numerical
simulations, they showed that if their vertical feed rate trajectory was followed, in an open-loop manner, the flatness would be improved. Feedback force control and power
control has been successfully applied to improve flatness in the area of robotic deburring of weld beads and mold finishing Kurfess T.R, 1992. With this strategy, a grinding
model that relates material removal rate to forcepower is used to back calculate a forcepower trajectory which, when applied, causes the generated workpiece to become
flatter. The implementation of these schemes requires the priori knowledge of the
workpiece geometry and flatness, which in some industrial applications are uncertain variables.
Review of the research work reveals that much work has been done on various aspects of grinding to produce a flatter surface. In this work, a study focused on the
surface grinding machine of mild steel and carbon steel has been carried out. Consequently, an analysis on the influence of feed rate and depth of cut were performed.
3 Coordinate Measuring Machine is use to inspect a specimen in order to produce a flatter
surfaces. This was done using the technique of design of experiments DOE.
1.2 Background of problems.
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