Studies on Centerless Grinding (3rd Report). Evaluation Function of Grinding Conditions.

Determination of waviness decrease rate by measuring the frequency characteristics of the grinding force in centerless grinding

“…(2) that r N (jn) is determined by multiplying r 0 (jn) by the waviness decrease rate for N revolutions, κ N r (jn). In normal grinding operations, as the absolute value of κ r (jn) is less than 1, the waviness decreases exponentially with increasing N during grinding, which leads to the workpiece profile approaching a perfect circle [9]. Though the frequency components of waviness on the initial workpiece are distributed over a wide frequency range, generally at a low frequency region (that is, region with small n), the waviness amplitudes are bigger than those at a high frequency region.…”

“…Assuming disturbances such as the waviness on the circumference of the grinding wheel and regulating wheel, and the vibration of worktable, etc. are enough small to neglect, the relationship between r 0 (jn) and r N (jn) will be as follows [9]: where κ r (jn)…”

“…is the waviness decrease rate, the evaluation function of the grinding conditions [9]. κ = K m /(K m + K s ) (K m , the machine stiffness and K s , the grinding stiffness), the machiningelasticity parameter [3], can be obtained from the timeconstant of the grinding force and the workpiece rotation speed [8].…”

“…Consequently, in order to re-setup the optimum grinding conditions efficiently and accurately, it is necessary to automatically select the process parameters by closed-loop control. For this purpose, an evaluation function of grinding conditions called the waviness decrease rate has also been provided [9], In order to build a closed-loop control system, however, it is necessary to find a practical way to determine the waviness decrease rate. In this paper, at first the relationship between the waviness decrease rate and the dynamic components of grinding force was investigated analytically.…”

A new through-feed centerless grinding technique using a surface grinder

“…With the increasing of the stock removal ı from 25 m to 50 m, the final workpiece cylindricity E c improves from 3.93 m to 1.49 m, and the roundness E r improves from 1.53 m to 0.74 m, respectively. This is because the total number of workpiece revolutions in a grinding cycle, an important factor affecting the workpiece roundness significantly as demonstrated by Gallego (2007) and Wu et al (1999), depends on the stock removal ı.…”