|Budget Amount *help
¥10,500,000 (Direct Cost : ¥10,500,000)
Fiscal Year 1999 : ¥4,100,000 (Direct Cost : ¥4,100,000)
Fiscal Year 1998 : ¥6,400,000 (Direct Cost : ¥6,400,000)
In order to achieve high material removal rate in surface grinding, the concept of speed-stroke grinding was proposed. High speed and high acceleration in reciprocating motion of the table system were attained by applying the linear motor driven table system. The maximum acceleration and speed attained were 0.7G and 60 m/min, respectively, which are much higher than the conventional hydraulic driven table system.
As the first phase of the study, accuracy of the table motion, such as positioning accuracy, pitching, and yawing were measured. In addition, forced vibration of the spindle head induced by the table reciprocation was carefully measured. Taking advantage of the linear motor, acceleration and deceleration patterns of the table motion were optimized for reducing the oscillation force. This approach was quite successful and the forced vibration was suppressed by applying the sinusoidal patterns of the acceleration. As the result, it was confirmed that the planed performance of the grinding machine was achieved.
Following the performance test of the grinding machine, a series of grinding tests was conducted. Performance indexes of the process were, grinding force, temperature, surface roughness, and grinding wheel wear. Selected workpiece materials were steel and engineering ceramics. Through the grinding tests, it was confirmed that the speed-stroke grinding was effective for reducing the grinding force as well as grinding temperature keeping the material removal rate constant, I.e., by increasing the workpiece speed while reducing the depth of cut, grinding force can be significantly reduced. This is particularly advantageous for grinding of difficult to machine materials.