Toshiba Kikai Kabushiki Kaisha

Tadashi Sasaki

Takeshi Momochi

Masahito Shiozaki

Tomoo Hayashi

Michio Matsumoto

Kenichi Suzuki

Katsuyoshi Aiso

Takeshi Goto

A thermal displacement correcting apparatus suitable for a machine tool (1) provided with a mechanism for feeding a main spindle (2) is disclosed. Three magnetic flux generating bodies 61 to 63 are fixed to the main spindle; a magnetic sensor (7) is fixed to the machine tool to detect the magnetic flux generated by the magnetic flux generating body at each predetermined spindle feed position; a thermal displacement value detecting section (14A) detects the thermal displacement values of the main spindle on the basis of outputs of the magnetic sensor at the respective spindle feed positions; a thermal displacement correction value calculating section (15) calculates a correction function on the basis of the detected thermal displacement values and previously determined reference values, and obtains the thermal displacement correction value in accordance with the calculated correction function at each spindle feed position; and a spindle feed command correcting section (16) corrects the spindle feed command applied to the spindle feed motor on the basis of the obtained thermal displacement correction value at each spindle feed position.

Thermal displacement correcting apparatus for machine tool

A complete-circle operation of a machine tool controlled by an NC-device. Even if the NC-device gives operation commands for respective shafts of the machine tool on the basis of a control locus which is to be a complete circle, the actual operation locus of the machine tool is not a complete circle because the machine tool generates errors due to various causes such as thermal deformation, machine accuracy, etc. If the errors are corrected individually to improve the accuracy, the complexity of the processing cannot be avoided. It is assumed that the operation locus of the machine tool which is controlled for a complete circle becomes an ellipse due to errors involved. A simple process corrects the ellipse such that it is converted to a complete circle.

Ellipse interpolation control method by an NC-device

Growing community of inventors

Numazu, Japan

Tadashi Sasaki