Abstract:
A method for measuring the diameter and eccentricity of a crankpin of a crankshaft which is ground on a grinding machine. A reference plate is provided on a headstock, which is disposed on a table to support the crankshaft. A measurement apparatus having a probe is disposed on a wheel head. Through movements of the table and the wheel head, the probe is first brought into contact with a reference surface of the reference plate, and is then brought into contact with the outer circumferential surface of the crankpin at outermost and innermost points. The distances between the reference surface and the outermost and innermost points are measured, and the diameter and eccentricity of the crankpin are calculated on the basis of the measured distances and the position of the reference surface.
Abstract:
On a grinding machine, a workpiece having eccentric cylindrical portions is rotated around the work spindle axis so that the eccentric cylindrical portions effects a planetary motion. A grinding wheel is reciprocated toward and away from the work spindle axis in synchronism with the planetary motion and is also fed toward the work spindle axis to grind the eccentric cylindrical portion into a target cylindrical profile. Upon completion of a part of the grinding operation, the eccentric cylindrical portion under machining is indexed to a predetermined angular position. A diameter measuring device is moved from its rest position to a measuring position to measure the diameter of the eccentric cylindrical portion. Comparing the measured diameter with a target diameter to obtain a residual difference in diameter, the grinding machine further operates to perform a finish grinding according to the residual difference until the diameter reaches the target size, whereby the eccentric cylindrical portion can be finished precisely using a general purpose measuring device.
Abstract:
It is an object of the present invention to provide a bed of a machine tool to be stably leveled and supported by three support points and to reduce the strain of the bed of which structure is simplified. The bed 10 of the machine tool 100 according to the present invention comprises three props 60, 61-63, 70, 71-73 and a ceiling 18. The props 60, 61-63, 70, 71-73 are arranged as a triangle. The ceiling 18 is put on the props 60, 61-63, 70, 71-73 and supports at least one tool box 30 and work saddle 20. In the triangle in view of horizontal plane, there exists center of gravity of the whole machine tool 100.