Machine tool having inspection function for deteriorated state of spindle

Abstract

The invention provides a machine tool having an inspection function for a deteriorated state of a spindle. In order to make it possible to inspect a deteriorated state of a spindle incorporated in a machine tool without disassembling the machine tool, a command for speed V0 is output to the spindle and, when the rotating speed of the spindle reaches V0, power of a spindle motor is interrupted and a timer is started. The spindle continues to rotate with inertia while decelerating. time (T) clocked by the timer when the spindle speed decreases to zero is read. Whether the time (T) is in a range between the upper (2) and lower (1) limits is determined, when the time (T) is outside the range, the spindle is considered in the deteriorated state, and an alarm is output. When time (T) measured by the timer is not greater than the lower limit (1), the spindle and a bearing of the spindle are deteriorated and friction resistance increases. Moreover, when time (T) measured by the timer is larger than the upper limit (2), the deterioration of the oil holding force of grease of the bearing can be speculated and the deteriorated state of the spindle can be inspected.

Description

technical field [0001] The present invention relates to a machine tool provided with a function of inspecting the deterioration state of a spindle included in the machine tool. Background technique [0002] The spindle of a machine tool has a lifespan, and if it is used for a long time, it will deteriorate, and poor rotation may occur due to deterioration of machining accuracy, ablation of bearings, and the like. When such inconvenience occurs, it is necessary to repair it, but there are cases where there are no symptoms due to ablation of the bearing or the like. At such a time, in order to maintain the production of the factory, urgent repairs are required. However, in the absence of immediate replacement parts, the factory's production capacity has dropped significantly. Therefore, if it is possible to check the deterioration state of the main shaft to detect signs of inconvenience, it is possible to avoid a sudden reduction in production at the factory by replacing the...

AI Technical Summary

Problems solved by technology

The bearing friction measurement method described in Japanese Patent Laid-Open No. 2009-80092 requires a special bearing friction measurement device, and cannot inspect the bearings installed in the equipment

Therefore, it is impossible to detect the deterioration state (deterioration state of the spindle bearing) of the spindle in a usable state for the machine tool without disassembling the spindle head.

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