| 摘要 |
PURPOSE:To correct the thermal displacement error of a profile milling machine properly, by detecting the thermal displacement error due to the thermal expansion of a tracer arm then providing said error signal as the correction input to the detection signal of a tracer head. CONSTITUTION:The thermal displacement of a tracer arm 22 is detected by a sensor 25 then the output signal from said sensor is converted into a spindle center and a tracer center thermal displacement through a thermal displacement detecting circuit 26 thus to produce the thermal displacement DELTAX, DELTAY, DELTAZ of the tracer arm 22. Here DELTAX is the thermal displacement error mainly due to the thermal expansion of the tracer arm 22 while DELTAY and DELTAZ are the displacement error due to the warp caused by the temperature distribution of the tracer arm 22. While the falling amounts epsilonx, epsilony, epsilonz of the stylus at the profiling are detected and the output signals epsilon'x, epsilon'y, epsilon'z where the thermal displacements are subtracted from said falling amounts at the subtractor 27 are provided to a profile controller 28 to perform the profile control thus to eliminate the thermal displacement error of the tracer head 23. |
