A power tool includes a control for the motor of the power tool that senses an operating characteristic of the motor and controls the operation of the power tool based on the sensed characteristic. The sensed characteristic includes variations in reluctance of the motor. A controller may sense changes on load on the motor as a result of interaction between a working element such as a saw blade or drill bit and the work piece. The controlled operation may include variation in speed or torque or both, or may include stopping the motor. Emergency conditions may be sensed by changes in reluctance.

A machine tool for machining a workpiece includes a spindle configured to rotate a holder mounted with a tool used for machining, one or more moving shafts configured to move the holder and/or a work base on which the workpiece is placed, a torque measurement unit configured to measure driving torque of the spindle and/or the one or more moving shafts, a reference value calculation unit configured to use, as a reference value, the driving torque measured by performing a no-load operation by rotating the spindle in a normal state, a torque comparison unit configured to compare, to the reference value, the driving torque measured by performing a no-load operation by rotating the spindle before actual machining, and an alarm unit configured to determine whether to issue an alarm on the basis of results of the comparison.

An abnormality detection apparatus for working tools configured to be used in a machining process performed by a machine tool, the abnormality detection apparatus includes a storage portion which previously stores correlations between features of a plurality of operating portions relation to the machining process performed by the machine tool, and a tool condition of each of a plurality of working tool types, and a tool condition determining portion which determines the tool condition of the working tools based on the correlations.

An information measuring device includes a sensor that obtains information on a phenomenon periodically occurring on an apparatus while being synchronized with the steady repetition of an operation and a control device. The control device associates the obtained information with an operation phase in the operation so as to generate change in the phenomenon in one cycle based on the information obtained during the operation of several times. Meanwhile, an operation cycle where the operation is repeated in the apparatus, a sampling cycle, and a duration where the operation is steadily repeated in the apparatus are included in measurement parameters. The control device calculates an optimum measurement parameter from a relation between the measurement parameters on at least one of the measurement parameters and changes the measurement parameter as a target to the optimum measurement parameter.

A spindle abnormity detection device includes a first sensor configured to measure oscillation of a spindle of a machine tool, a second sensor configured to measure radial runout of an axis of a tool unit attached to the spindle, and a computer configured to perform abnormity determination of the spindle based on an oscillation comparison result and a runout comparison result, the oscillation comparison result being obtained by comparing a detection result obtained by the first sensor with an oscillation standard of the spindle, the runout comparison result being obtained by comparing a detection result obtained by the second sensor with a runout standard of the tool unit.

A monitoring device includes: a distribution generating unit configured to generate an execution time distribution that is a frequency distribution of an execution time of the program; a storage unit configured to store at least one kind of abnormality information indicative of an execution time distribution as to an abnormality; a calculation unit configured to calculate an occurrence probability of abnormality, based on information indicating the execution time distribution generated by the distribution generating unit and the abnormality information stored in the storage unit; a threshold setting unit configured to set a probability threshold for the abnormality information; and a determination unit configured to determine that there is a sign of an abnormality when the occurrence probability is equal to or higher than the probability threshold.

A machine tool for machining a workpiece includes a spindle configured to rotate a holder mounted with a tool used for machining, one or more moving shafts configured to move the holder and/or a work base on which the workpiece is placed, a torque measurement unit configured to measure driving torque of the spindle and/or the one or more moving shafts, a reference value calculation unit configured to use, as a reference value, the driving torque measured by performing a no-load operation by rotating the spindle in a normal state, a torque comparison unit configured to compare, to the reference value, the driving torque measured by performing a no-load operation by rotating the spindle before actual machining, and an alarm unit configured to determine whether to issue an alarm on the basis of results of the comparison.

An abnormality factor identification apparatus includes a sensor signal obtaining unit that obtains sensor signals associated with the physical state of a machine, an operating state determination unit that determines operating states of the machine based on information obtained from the machine, an abnormality level calculation unit that calculates the abnormality levels of the sensor signals for each operating state of the machine determined by the operating state determination unit, and a factor identification unit that determines a factor in an abnormality in the machine from historical data being a series of the abnormality levels for each operating state.

The disclosure provides a milling system and method under different lubrication conditions. The system uses a tool to mill the workpiece, a force measuring system to measure the milling force, a tool change system to replace the tools, a tool storage to store the tools. It can store the tools, provide the lubricating oil to the milling surface, select different tools according to different processing conditions, select the best angle differences of the unequal spiral angle tools according to different conditions comprising dry cutting, casting-type lubrication, minimal quantities of lubrication or minimal quantities of nanofluid lubrication, and/or choose the optimal tool according to different cutting parameters in order to obtain the minimum milling force.

A system for detecting a damaged tool of multi-axis head machining equipment includes multi-axis head machining equipment, and a damaged tool detecting device connected to the multi-axis head machining equipment to detect a damaged tool, the damaged tool detecting device being configured to measure a current and a current change amount of the multi-axis head machining equipment to monitor a machining load, and a derivative and machining energy of the machining load, so as to detect whether there is an abnormality in a plurality of tools mounted on a multi-axis head during machining.