Okuma Corporation

Okazaki, Japan

Okuma Corporation

Okazaki, Japan
SEARCH FILTERS
Time filter
Source Type

Patent
OKUMA Corporation | Date: 2016-11-29

A fully-closed loop position controller with a velocity control system based on a velocity feedback of mixed velocities of a motor velocity and a load velocity. The fully-closed loop position controller identifies a ratio of load moment of inertia in real time to select an optimum mix gain in accordance with a changing ratio of load moment of inertia such that a position loop gain and a speed loop gain can be varied accordingly. The fully-closed loop position controller controls the load position based on the mix gain, the position loop gain, and the velocity loop gain.


Patent
OKUMA Corporation | Date: 2016-11-16

A window function calculator applies a Hann window function to Vd (n) to obtain a numeric value Vw (n). For twenty successive numeric values Vw(n) for every twenty numeric values (N=20), each of the Fourier calculators to executes Fourier calculation. Further, the SRSS calculators to calculate square root of sum of squares of SIM and COS components of respective orders of the results of Fourier calculation as numeric values A2, A3, A4, A5. A subtractor calculates a numeric value Ci=A3A5, while a subtractor calculates a numeric value Si=A4A2. A Frequency calculator calculates a numeric value Fi=(m+1+2*ATAN2 (Ci, Si)/)/(NT), which indicates the frequency identified. An amplitude calculator doubles the square root of the sum of squares of the numeric values Ci and Si, and calculates a numeric value Ai that indicates the amplitude of the frequency identified.


Patent
OKUMA Corporation | Date: 2016-12-22

A motor control device calculates a velocity difference based on a velocity command and a velocity detection value of a motor and an excitation current common phase voltage difference based on an excitation current command value and an excitation current detection value, and judges that demagnetization occurs when the following conditions are all met: the excitation current common phase voltage difference exceeds a voltage threshold; the velocity difference exceeds a velocity threshold; and acceleration is being performed.


Patent
Okuma Corporation | Date: 2016-07-14

A bearing diagnostic device senses a failure in a bearing of a machine tool including a rotation shaft device. The bearing diagnostic device includes a rotation counting unit, a temperature measuring unit, a frictional torque calculating unit, a rolling speed calculating unit, a bearing characteristic calculating unit, a storage unit, and a determination unit. The frictional torque calculating unit is configured to calculate a frictional torque of the rotation shaft device. The rolling speed calculating unit is configured to calculate a rolling speed of the bearing from the count of rotations. The bearing characteristic calculating unit is configured to calculate a bearing characteristic from the frictional torque and the rolling speed. The determination unit is configured to compare the bearing characteristic calculated by the bearing characteristic calculating unit with a reference bearing characteristic stored in the storage unit to determine a presence of a failure.


Patent
Okuma Corporation | Date: 2016-06-22

An information acquisition device for machine tool includes a time series information recording unit, an event information recording unit, and an output unit. The time series information recording unit is configured to acquire machine information in time series at a predetermined timing. The event information recording unit is configured to record at least one of: a change content and time at which any one of step information related to a process step, tool information, control panel information related to a control panel of the machine tool, workpiece information, and operator information is changed; and an instruction and time at which the instruction related to a start or an end of machine control execution is issued. The output unit is configured to output time-series data of the machine information recorded in the time series information recording unit together with event data recorded in the event information recording unit.


Patent
OKUMA Corporation | Date: 2016-09-09

A resolver for a rotation position detection device comprises a rotor portion having a resin gear having a hole formed at a center portion thereof through which a stationary shaft passes, and a rotor core connected to the resin gear; and a stator portion having the stationary shaft, an excitation wiring and a detection wiring, a back core, and a resin housing, wherein the excitation wiring and the detection wiring are arranged around the stationary shaft at a constant distance from the stationary shaft in a diameter direction, the back core is adjacent to or in contact with the stationary shaft, and the resin gear has a shape whose central portion projects in the shaft direction so as to be in contact with the back core.


Patent
Okuma Corporation | Date: 2016-10-21

A main spindle controller of a machine tool varies a rotation speed of a main spindle that grips a workpiece to a varied maximum speed higher than a reference rotation speed set value as a set value of a reference rotation speed by a variation width set value as a set value of a variation width or a varied minimum speed lower than the reference rotation speed set value by the variation width set value in units of the tool path. At the same time, the main spindle controller refers to speed condition information that indicates a condition of the preliminarily stored reference rotation speed and variation width assuming that a chatter vibration is to be reduced, and when at least one of the reference rotation speed set value and the variation width set value does not satisfy the condition of the speed condition information.


Patent
OKUMA Corporation | Date: 2016-12-08

In a system including a master station, slave stations, and a loop communication path for connecting the master and slave stations, the master station measures for each of the slave stations a transmission lag time from transmission of a communication frame in a forward direction through a loop communication channel in the master station to reception of the communication frame returned in a backward direction from the slave station, and calculates timer correction times for the slave stations based on both the transmission lag times measured for the slave stations and delay time information representing delay times caused by communication frame processing in the slave stations. Each of the slave stations includes a transmission/reception switch which switches a communication frame transmitting/receiving direction between the forward and backward directions in the loop communication channel, to allow timer synchronization in the loop communication path formed by the single communication channel.


A main spindle failure detection device for a machine tool includes a rotation speed detection unit, a reach time estimation unit, and a determining unit. The reach time estimation unit is configured to estimate a reach time in which the rotation speed of the main spindle reaches a predetermined rotation speed threshold using a non-linear model based on a rotation speed of the main spindle detected at a start of an inertia operation and a rotation speed of the main spindle detected after an elapse of preset measurement time from the start of the inertia operation. The determining unit is configured to compare the reach time estimated by the reach time estimation unit with a preset reach time in which the rotation speed reaches the rotation speed threshold, so as to determine a failure in the main spindle based on a result of the comparison.


Patent
Okuma Corporation | Date: 2016-10-03

In an NC device having a function as a monitoring apparatus for a machine tool, a monitoring parameter and a retracting parameter which are set and inputted through an input unit by an operator, can be stored in a storage unit. When, for example, monitoring is performed by using a load on a main spindle as machine information, a machining monitoring unit displays a monitored state on a monitor, and compares a threshold value, of the load on the main spindle, according to which occurrence of abnormality is determined, and which is set in the monitoring parameter, and an instruction load generated by a machine operation instruction unit with each other, to determine whether or not abnormality has occurred. When abnormality is determined as having occurred, a retracting instruction is transmitted to a retracting instruction unit according to the retracting parameter, and display is performed on the monitor.

Loading Okuma Corporation collaborators
Loading Okuma Corporation collaborators