Okuma Corporation Patent applications |
Patent application number | Title | Published |
20140364993 | CONTROL METHOD FOR MACHINE TOOL - In a control method for a machine tool including two or more translation axes and at least one rotation axis, a command for a distal end position of a tool and an attitude of the tool is provided to correct an error in the distal end position and the attitude with respect to a workpiece due to a geometric error to calculate a command value for controlling the translation axes. The method includes calculating the command value on the basis of a command coordinate value for the distal end position, a converted coordinate value obtained by converting a coordinate value of a rotation center point of the rotation axis in an actual state into a coordinate value without an error in inclination, and an axial unit vector for the ideal rotation axis. | 12-11-2014 |
20140320057 | POSITION CONTROLLER - A position controller sets a variable friction compensation value which varies in accordance with a change in sliding characteristics by providing a variable friction compensation value calculation unit that includes a sliding torque normalization calculation unit that normalizes a sliding torque at a predefined speed; a compensation value amplifying ratio calculation unit that calculates a compensation value amplifying ratio based on the sliding torque at the normalized speed; and multipliers. | 10-30-2014 |
20140318246 | INERTIA ESTIMATING METHOD AND INERTIA ESTIMATING APPARTUS OF POSITION CONTROL APPARATUS - A torque command value and an acceleration detection value are accumulated when a driven portion is subjected to acceleration/deceleration driving, and, from a ratio between the two, inertia of a movable portion is calculated. By executing the acceleration/deceleration driving about a position where influence of gravity torque is zero, the influence of the gravity torque included in the torque command value before and after the center position is offset, whereby inertia can be estimated correctly even with a machine structure in which the influence of gravity differs depending on the position of the motor. | 10-30-2014 |
20140318019 | DOOR MECHANISM OF MACHINE TOOL - A door mechanism of a machining center includes a wide door panel, narrow door panels, a pair of upper and lower slide rails with a U-shaped section into which the wide door panel and the narrow door panels are to be fitted, three motors that serve as drive units for independently driving the wide door panel and the narrow door panels. The wide door panel and the narrow door panels are arranged in line so as to be slidable in the width direction such that an opening portion is opened and closed, and the opening width has a length suitable for the length of the largest workpiece on one pallet. | 10-30-2014 |
20140312548 | MACHINE TOOL - A machine tool includes a slide table supported by an upper portion of a main body of the machine tool so as to be horizontally slidable, a rotary table provided on the slide table so as to be rotationally indexable about a vertical axis extending in the direction that is orthogonal to the direction of horizontal slide movement of the slide table, and a motor provided in the slide table to rotate the rotary table. A housing space is formed in the main body to house a lower portion of the slide table. At least a part of the motor provided in the slide table is placed in the housing space. | 10-23-2014 |
20140309766 | Numerical Controller - A numeric controller is provided with a three-dimensional model storage which stores a three-dimensional model of at least one of a workpiece and a jig; a three-dimensional measuring unit which integrally measures shapes of the workpiece and the jig fixed to the machine tool; and a shape processor generating an integrally measured model based on the measured data, in which the workpiece and the jig being integrally recognized, measured by the three-dimensional measuring unit, and further generating, regarding at least one of the workpiece and the jig, an individually measured model in which the workpiece or the jig is individually measured based on the generated integrally measured model and the three-dimensional model of the workpiece or the jig. | 10-16-2014 |
20140306644 | Electric Motor Control Device - An electric motor control device for performing tandem control for driving one movable component includes, for each electric motor, a position controller, a speed controller, and a current controller. Further, each electric motor also has a preload controller for adding a preload torque to a torque command Tm calculated by the speed controller, and to a torque command Ts calculated by the speed controller. The preload controller calculates a minimum necessary preload torque for eliminating backlash in accordance with a position of the movable component. | 10-16-2014 |
20140217952 | Position Control Apparatus - A position control apparatus is configured to perform full-closed control for controlling the position of a driven member. The position control apparatus includes a vibration period and amplitude detector that detects a vibration period and a vibration amplitude included in a difference value between the position command value and the driven member position detection value. The position control apparatus also includes a constant vibration detector that outputs, as a vibration period of the constant vibration, a vibration period obtained while the driven member is not in an acceleration/deceleration state and the vibration period and the vibration amplitude detected by the vibration period and amplitude detector are equal to or greater than a vibration period threshold value and a vibration amplitude threshold value, respectively. The position control apparatus also includes a control parameter changer that changes the control parameter based on the vibration period output from the constant vibration detector. | 08-07-2014 |
20140216218 | CUTTING METHOD AND CUTTING APPARATUS - A tool-main-spindle, whose cutting angle can be changed, is translated by an X-axis moving mechanism portion on an X-axis provided in a plane perpendicular to an axis of a work, and is translated on a Y-axis by a Y-axis moving mechanism portion. Cutting of the work is performed by setting the cutting angle of the tool-main-spindle to an angle of the cutting tool at which the work has large dynamic rigidity, and causing an axis of a cutting tool to cross the work axis, and cutting the work with the cutting tool toward the axis of the work by cooperatively operating the X-axis moving mechanism portion and the Y-axis moving mechanism portion. | 08-07-2014 |
20140210297 | Three-Phase AC Motor - A plurality of coils C | 07-31-2014 |
20140126845 | MAIN SPINDLE DEVICE OF MACHINE TOOL - A main spindle device of a machine tool includes a plurality of bearings that rotatably support a main spindle of the machine tool, and that are placed inside a housing with a pressure receiving member interposed between the bearings and the housing. The pressure receiving member is capable of moving in a direction perpendicular to an axial direction of the main spindle. A pressure chamber, which a pressure medium pressing the pressure receiving member toward the bearings in the perpendicular direction is supplied to, is formed in the housing. A plurality of the pressure chambers are independently formed in the housing so as to correspond to the bearings, respectively. The main spindle device further includes a plurality of adjustment units provided independently so as to correspond the pressure chambers, respectively, and each capable of independently adjusting a pressure of the pressure medium for a corresponding one of the pressure chambers. | 05-08-2014 |
20140121817 | MACHINE TOOL - A machine tool includes a number-of-same-rotation-speed-cutting-passes computing section that decides the number of same rotation speed cutting passes. The number-of-same-rotation-speed-cutting-passes computing section determines the cutting mode of a threading process based on a set machining program etc., and automatically decides an optimal number of same rotation speed cutting passes according to the cutting mode. Thus, even unskilled operators can easily suppress chatter vibrations, and can easily use the machine tool. | 05-01-2014 |
20140121816 | MACHINE TOOL - A machine tool includes a first-pass rotation speed computing section. The first-pass rotation speed computing section automatically decides whether the main spindle rotation speed in the first pass should be a high rotation speed or a low rotation speed so that cutting in the last tool pass is performed at the high rotation speed. Thus, cutting of the last tool pass at the low rotation speed can be reliably prevented. | 05-01-2014 |
20140114462 | CHATTER VIBRATION SUPPRESSING METHOD AND MACHINE TOOL - A chatter vibration suppressing method includes acquiring a moment of inertia of a rotating body, recording a value indicating the acquired moment of inertia into a machining program, and calculating a variable amplitude and a variable period when a rotation speed of the rotating body is varied in order to suppress chatter vibration from the value indicating the moment of inertia recorded in the machining program and the maximum input power of a motor for rotating the rotating body. | 04-24-2014 |
20140094953 | THREAD CUTTING MACHINE - A thread cutting machine for cutting a thread by rotating a main spindle and moving a feed axis includes a main-spindle speed computing section that computes and outputs a rotation speed of the main spindle based on a main-spindle rotation speed instruction for each thread cutting pass, and an acceleration/deceleration time computing section that computes and outputs an acceleration/deceleration delay time of the feed axis for each thread cutting pass so that a product of multiplication of the acceleration/deceleration delay time of the feed axis and the rotation speed of the main spindle is the same for all thread cutting passes. | 04-03-2014 |
20140083244 | PROTECTIVE DEVICE FOR SLIDING SURFACE - Cover frames configure a slide cover. Each of the cover frames has, at a lower end thereof, a wiper that contacts an outer surface of the cover frame located immediate inside. Each of the cover frames also has, on an upper inner surface thereof, a roof-shaped backboard that extends over the cover frame inside. The backboard is provided slightly below an upper end of the cover frame. Each of the cover frames is provided, on an upper outer surface thereof, with a sliding shoe that contacts an inner surface of the cover frame located immediate outside. The innermost cover frame is fixed to a column in which a sliding surface is formed, and has a bottom plate that encloses an area below the sliding surface. In an upper portion of the bottom plate, an oil receiving portion is formed to receive lubricant flowing from the sliding surface. | 03-27-2014 |
20140069252 | GROOVING METHOD, GROOVING TOOL, AND GROOVING TOOL HOLDING STRUCTURES - A plurality of cutting blades is linearly arranged on the right and left sides of a plate that is placed vertically. The cutting blades on one side are arranged so as to face downward, and the cutting blades on the other side are arranged so as to face upward. With a tool thus formed, a cutting operation is performed by making a circular motion in a plane in which the cutting blades are formed, and the cutting operation using the circular motion is repeated with the tool shifted by a predetermined pitch in a cutting direction. The tool is tilted in the cutting plane when subjected to high stress. | 03-13-2014 |
20130309034 | MACHINING VIBRATION SUPPRESSING METHOD AND MACHINING VIBRATION SUPPRESSING APPARATUS FOR MACHINE TOOL - An apparatus includes an external input device that allows setting of the amount of runout and the phase of each cutting edge, a computation device that acquires the rotational phase of a tool and that computes the angular velocity and the phase of vibration of two, X-axis and Y-axis, feed shafts on the basis of the input amount of runout and angular velocity of each cutting edge to generate a feed shaft control signal, and a numerical control device that controls feed in the X-axis and the Y-axis directions. The numerical control device relatively vibrates a workpiece in synchronization with the angular velocity of the tool on the basis of the results of computation performed by the computation device. | 11-21-2013 |
20130234643 | SPINDLE POSITIONING DEVICE - An acceleration command calculator | 09-12-2013 |
20130226355 | NUMERICAL CONTROL MACHINE - A numerical control machine estimates a future rotational speed ahead by a delay time that is a phase difference between a rotational speed fluctuation of a main spindle and a feed rate fluctuation of a feed axis, and fluctuates the feed rate such that a constant ratio is maintained with the estimated rotational speed. | 08-29-2013 |
20130193901 | METHOD OF CONTROLLING LINEAR MOTOR - In a linear motor used for a driving axis of a large-size machine tool having a very long driving stroke, pole position correction values at a plurality of stroke positions are stored in a memory. A pole position correction value corresponding to an actual stroke position of a slider is calculated based on the stored pole position correction value. A corrected electrical angle offset value derived based on the calculated pole position correction value is used to control the linear motor. | 08-01-2013 |
20130178347 | MULTITASKING MACHINE TOOL - In a multitasking machine tool, a first tool post including a tool spindle configured to allow a tool to be detachably attached thereto is configured to be slidable in predetermined directions, while a second tool post is configured to allow a tool to be detachably attached thereto. A tool-change part includes at least one gripper configured to hold a tool to be attached to the second tool post. An automatic tool changer is configured to detachably attach the tool-change part (as well as to change the tool installed) to the tool spindle of the first tool post positioned in a first tool-change region. Change of the tool attached to the second tool post is carried out by a motion (sliding and/or rotation of the tool spindle) of the first tool post (with the tool-change part attached to the tool spindle thereof) located in a second tool-change region. | 07-11-2013 |
20130099719 | MACHINE TOOL - A machine tool includes a main axis | 04-25-2013 |
20130096868 | SPEED MONITORING DEVICE - There is provided a speed monitoring device which can use a low resolution position sensor and provide a high speed response without false detection. The speed monitoring device stores, in a memory unit, a permitted margin PM, a comparison distance VC which is a maximum movement distance permitted for a moving element within one cycle period, and positional data P(t−nT) (n is a natural number equal to or less than M) of the moving element obtained from the present time t to M cycles ago. During speed determination, whether |P(t)−P(t−nT)|>VC*n+PM holds true is determined for every integer n from 1 to M. When the inequality holds true, it is determined that the speed exceeds the speed limit. | 04-18-2013 |
20130073251 | MONITORING METHOD AND MONITOR APPARATUS FOR MONITORING ROTATION SPEED OF ROTARY SHAFT IN MACHINE TOOL, AND MACHINE TOOL - When a rotation speed is fluctuated, a fluctuation diagram showing the relationship between a fluctuation amplitude and a fluctuation period of the rotation speed is displayed on a monitor. In addition to a current setting value, a settable range of the fluctuation amplitude and the fluctuation period is displayed on the fluctuation diagram. At least one of an optimal fluctuation period P | 03-21-2013 |
20130046405 | TOOL PATH GENERATION DEVICE, TOOL PATH CALCULATION METHOD, AND TOOL PATH GENERATION PROGRAM - A tool path generation device that calculates a tool path to be used by a machine tool device, and that provides a high machining efficiency with suppressed occurrence of chatter vibration by calculating machining conditions in consideration of a chatter vibration increase and decrease affecting value that affects increase and decrease in chatter vibration. | 02-21-2013 |
20130015742 | SYNCHRONOUS MOTORAANM Inoue; YoshimitsuAACI Niwa-gunAACO JPAAGP Inoue; Yoshimitsu Niwa-gun JPAANM Satake; AkiyoshiAACI Niwa-GunAACO JPAAGP Satake; Akiyoshi Niwa-Gun JP - A synchronous motor | 01-17-2013 |
20130013250 | ABSOLUTE POSITION DETECTOR WITH ABNORMALITY DETECTION FUNCTION - In an absolute position detector, a relative error calculation circuit calculates, at times indicated by a clock signal C | 01-10-2013 |
20120318062 | VIBRATION DETERMINATION METHOD AND VIBRATION DETERMINATION DEVICE - Determination of chatter vibration is done for a plurality of peak values that appears when frequency-domain vibrational acceleration is obtained through fast Fourier analysis on time-domain vibrational acceleration. In machining at a low rotation speed and machining using a tool with small flute number in particular, a type of chatter vibration that has occurred can be accurately determined, and “natural vibration type forced chatter vibration” occurring due to friction between a tool and a workpiece and an impact force caused by machining can also be determined. | 12-20-2012 |
20120304478 | METHOD FOR CALCULATING ERROR COMPENSATION VALUE OF MACHINE - When calculating a compensation value for a geometric error, a first index representing an order of connection of drive axes in a machine and a second index representing an order of connection of the drive axes including the geometric error are obtained. Then, a first vector is obtained by performing a matrix operation of a reference vector according to information on the connection in the first index, and a second vector is obtained by performing the matrix operation of the reference vector according to information on the connection in the second index. Thereafter, a difference between the first vector and the second vector is obtained as the compensation value. | 12-06-2012 |
20120280678 | STATOR AND RESOLVER - Coils are formed into a coil group for a single phase by serially connecting a plurality of coils so that the resulting magnetic flux distribution is a sine wave distribution. The coil group for a single phase is constituted by a plurality of coil sets, formed from two coils that are wound around two adjacent magnetic pole teeth, connected in series. Each coil set includes coils of the two magnetic pole teeth constituting that coil set wound in opposite directions to each other looking from the inside of the stator. An electrical wire extending from an end winding of each coil is turned back so as to run in a direction opposite to an electrical wire connection to a start winding of that coil, and is connected to either a start winding of the next coil or a connection terminal. | 11-08-2012 |
20120266783 | TABLE UNIT FOR MACHINE TOOL - A table unit for a machine tool includes a tilting table provided on a base and configured to be swingably indexable around a horizontal axis, a rotary table provided on the tilting table and configured to be rotatably indexable around a vertical axis orthogonal to the horizontal axis, and at least one motor disposed in the tilting table and configured to be driven to rotate the rotary table. An axis of a motor shaft of the motor is arranged in a plane formed by the horizontal axis and the vertical axis. | 10-25-2012 |
20120253708 | VIBRATION DETERMINATION METHOD AND VIBRATION DETERMINATION DEVICE - When generation of a chatter vibration is detected, a parameter calculation device calculates a first frequency range and a second frequency range. A determination validity is calculated in consideration of a rotation speed detection resolution and a frequency resolution, and based on a ratio of a frequency range of rotational-period forced chatter vibration to a frequency range of regenerative chatter vibration. It is determined based on the determination validity whether the generated chatter vibration is regenerative chatter vibration, rotational-period forced chatter vibration, or flute-passage-period forced chatter vibration. | 10-04-2012 |
20120253506 | METHOD AND PROGRAM FOR CALCULATING CORRECTION VALUE FOR MACHINE TOOL - The present invention provides a method and the like that are capable of calculating a correction value for a rotational axis and make it possible to correct an error in position or position and posture of a tool, which results from a geometric error, correct an error in posture of the tool, and also enhance the accuracy in machining by preventing a translational axis from operating in an infinitesimal manner due to a correction command. In a machine tool having two or more translational axes and one or more rotational axes, a correction value for each of the translational axes is calculated using a command position of each of the rotational axes, a coordinate value of a correction reference point as one point designated in advance in a command position space of each of the translational axes, and a geometric parameter representing the geometrical error. | 10-04-2012 |
20120253505 | METHOD AND PROGRAM FOR CALCULATING CORRECTION VALUE FOR MACHINE TOOL - The present invention provides a method of computing a correction value for the machine tool having two or more translational axes and one or more rotational axes for correcting error in a position and an orientation of the tool with respect to a workpiece due to the geometric error. The method includes a rotational axis correction value computing step (S | 10-04-2012 |
20120221139 | NUMERICAL CONTROL APPARATUS HAVING VIBRATION SUPPRESSION CAPABILITIES - A numerical control apparatus includes a program analyzing unit | 08-30-2012 |
20120219374 | SPINDLE DEVICE - A spiral groove flow passage with a clockwise spiral direction and a spiral groove flow passage with a counterclockwise spiral direction are provided inside a spindle. When the spindle is accelerated to rotate in the forward rotation direction, a pressure in the direction of causing a reverse flow of a coolant is applied to the left-hand spiral groove flow passage by the axial-flow pumping action, but a pressure in the forward direction is applied to the right-hand spiral groove flow passage by the same axial-flow pumping action to cancel out the pressure causing the reverse flow described above. | 08-30-2012 |
20120194121 | POSITION CONTROL APPARATUS - A position control apparatus calculates a position detection value by adding an output of a first-order delay circuit | 08-02-2012 |
20120175990 | MOTOR - A motor is provided. When m is half of a number of slots of one phase and n is a divisor of m, the overall parallel winding of a total number of parallels p is equally divided n-fold into partial parallel windings Ni, having a number of parallels p/n, each partial parallel winding Ni comprises m sub-coils, the m sub-coils including n types of m/n sub-coils having a number of turns tj, at least one of the sub-coils differing in number of turns from the other sub-coils, and, for each pair of the slots in the stator, one sub-coil of each partial parallel winding Ni is wound around the pair of slots, and n sub-coils wound around the pair of the slots include every one of the n types of the sub-coils of the numbers of tj. | 07-12-2012 |
20120165971 | THERMAL DISPLACEMENT CORRECTING APPARATUS AND METHOD FOR A MACHINE TOOL - A thermal displacement correcting apparatus includes a correction amount estimating device and a parameter automatic selecting device that, in a machine tool having two different sets of specifications that differ due to the presence/absence of a scale and different methods of measuring the lengths of a bed and a table, estimate a thermal displacement correction amount of the machine tool of each set of specifications. The two devices store a collection of parameters for an estimated thermal displacement calculation corresponding to each of the bed, the scale, the table, and a workpiece, as a database, and select the parameters belonging to the set of specifications from the database based on machine information according to each set of specifications, calculate estimated thermal displacements of the bed, the table, and the workpiece, or also the scale, according to the selected parameters, and combine the estimated thermal displacements. | 06-28-2012 |
20120133311 | MOTOR MAGNETIC POLE POSITION CORRECTION METHOD - A motor magnetic pole position correction method includes preventing a movement of a movable element of a direct drive motor by mechanical brake (step S | 05-31-2012 |
20120109360 | MACHINE TOOL - In a machine tool which includes a rotary shaft configured to allow a tool or a workpiece to be attached thereto, a driving unit for causing the rotary shaft to rotate is regulated to change a rotation speed of the rotary shaft in such a manner that the rotation speed oscillates with a given amplitude and a given period with respect to a given mean rotation speed, so that chatter vibrations can be suppressed. A parameter display control unit configured to cause a display device to display parameter information related to predetermined parameters for changing at least one of the mean rotation speed, the amplitude and the period is provided so that the parameters can be changed based upon the parameter information displayed in the display device. | 05-03-2012 |
20120101624 | METHOD AND APPARATUS FOR SUPPRESSING VIBRATION - A vibration suppressing method and a vibration suppressing device are disclosed. After detection of chatter vibration using at least one vibration detecting device, a stable rotation speed for suppressing the chatter vibration is calculated using a stable rotation speed calculating device. A determination device then compares a detection value detected by the vibration detecting device, a predetermined setting value, and/or a current value that is calculated based on at least one of the detection value and the setting value, to a predetermined determination reference value that is previously set. Thereafter, the determination device determines whether or not the stable rotation speed is adopted in accordance with the comparison result, and changes rotation speed of the rotary shaft to the stable rotation speed if the stable rotation speed is adopted. | 04-26-2012 |
20120097411 | METHOD FOR MONITORING ROTARY SHAFT ROTATION SPEED FLUCTUATION IN MACHINE TOOL, MONITOR APPARATUS, AND MACHINE TOOL - In suppressing chatter vibration of a rotary shaft in a machine tool by fluctuating rotation speed of the rotary shaft, easy setting of a fluctuation parameter is realized. In a monitor apparatus of the machine tool, a graph showing a fluctuation amplitude of the rotation speed is displayed. On this graph, a current fluctuation position (first point) is indicated by a black circle marker, and also, a power limit line L of a motor fluctuation period is depicted based on a predetermined equation. In an area not exceeding the power limit line L, a new fluctuation position (second point) having a larger fluctuation amplitude and a shorter fluctuation period than the current fluctuation position is calculated and indicated with an arrow A guiding this new point from the current fluctuation position. | 04-26-2012 |
20120095724 | OPERATING HISTORY MANAGEMENT METHOD AND OPERATING HISTORY MANAGEMENT APPARATUS - At least a rotation speed of a rotary shaft and a vibration acceleration in a frequency domain are stored as an operating history, and the operating history is stored not only when the rotation speed of the rotary shaft varies, but also when a maximum value of the vibration acceleration in the frequency domain exceeds a predetermined threshold. Therefore, variation in the rotation speed of the rotary shaft and the chatter vibration occurrence state can be stored in association with each other. Hence, an operator can learn the rotation speed of the rotary shaft and the chatter vibration occurrence state in association with each other. As a result, chatter vibration can be suppressed easily and effectively. | 04-19-2012 |
20120093603 | VIBRATION SUPPRESSING METHOD AND VIBRATION SUPPRESSING DEVICE FOR USE IN MACHINE TOOL - In a machine tool having a rotary shaft for use in rotating a tool or a workpiece, a plurality of stable rotation speeds at which the chatter vibrations are expected to be suppressed, and at least one switching rotation speed across which a dynamic characteristic of a rotary shaft system changes are stored. The plurality of stable rotation speeds may be determined from chatter vibrations detected using a vibration detection unit. Optimum rotation speed that is a rotation speed to which a rotation speed of the rotary shaft is changeable without crossing the switching rotation speed is selected from the plurality of stable rotation speeds, and the rotation speed of the rotary shaft is changed to the optimum rotation speed. Thus, chatter vibrations generated during rotation of the rotary shaft can be suppressed effectively. | 04-19-2012 |
20120093598 | MONITORING METHOD AND MONITORING APPARATUS FOR MACHINE TOOL, AND MACHINE TOOL - The monitoring apparatus includes vibration sensors that detect vibration accompanying machining, a rotation detector and a rotation detection section that detect rotation of a main spindle, and a stability limit and vibration distribution calculation section that creates, on the basis of vibration information obtained from the vibration sensors and a rotation speed of the main spindle detected by the rotation detector and rotation detection section, both a stability limit diagram illustrating a relationship between the rotation speed and a stability limit of the machining and a vibration distribution diagram illustrating a relationship between the rotation speed and the vibration, and displays the created diagrams on a monitor in a vertical arrangement. | 04-19-2012 |
20120065766 | VIBRATION SUPPRESSING DEVICE - A vibration suppressing device includes a memory unit storing a stable rotation speed calculated by an arithmetical unit in association with a rotation speed range that includes the stable rotation speed, in which, when a command rotation speed that is a rotation speed of a rotary shaft is inputted in starting machining operation by rotation of the rotary shaft and, the arithmetical unit determines whether the command rotation speed is included in the rotation speed range or not, reads out the stable rotation speed when the command rotation speed is included in the rotation speed range and outputs the stable rotation speed to an NC device instead of the command rotation speed, and starts the machining operation at the stable rotation speed. | 03-15-2012 |
20110316530 | ROTATION ANGLE DETECTION APPARATUS - In a rotation angle detection apparatus, a signal detected by a magnetoresistive element is digitalized before being subjected to subtraction of the optimum correction parameter therefrom in a subtractor, the optimum correction parameter being stored in advance in a memory. Note that during the initial transmission at the time of activation, the data size “n” of a detection target obtained by a CPU from a control device is transferred to the memory, so that the optimum correction parameter for the data size of the detection target is selected. With the above, the detection unit can relatively readily cope with a request for enlargement or the like of a through hole size made by a machine side, and detection accuracy is not deteriorated and an error in absolute position processing is reduced when the curvature of the detection target is changed. | 12-29-2011 |
20110281658 | ROTARY SHAFT DEVICE - In a rotary joint for a rotary shaft device, ring-shaped inner seals and outer seals are projectingly arranged, and concentric with faces of a front joint disk and a rear joint disk opposing with each other respectively. A ring-shaped inner space communicates with forward communication holes, and a ring-shaped outer space communicates with backward communication holes. The inner and outer space are adjacently arranged concentrically between the inner seals and the outer seals. The forward communication holes and the backward communication holes in the reciprocating flow passages and the front joint disk are arranged at an equal distance in the peripheral direction of the opposing faces. | 11-17-2011 |
20110280679 | COOLING STRUCTURE FOR MACHINE TOOL MAIN SPINDLE - A coolant supply section that supplies coolant to a main spindle and a coolant recovery section that recovers the coolant from the main spindle are formed in a housing. A coolant flow path that allows the coolant to flow from the coolant supply section to the coolant recovery section is formed in the main spindle. The coolant flow path in the main spindle includes a coolant receiving portion that receives the coolant supplied from the coolant supply section, and a plurality of hole-shaped flow paths formed to extend in the axial direction of the main spindle from the coolant receiving portion. The coolant receiving portion includes an annular groove that is recessed in the outer circumference of the main spindle. The hole-shaped flow paths are formed to extend generally straight toward the coolant recovery section and with an inclination to the radially outer side of the main spindle. | 11-17-2011 |
20110218666 | METHOD OF CONTROLLING THREAD CUTTING - The present invention provides a simple method of reducing an incomplete thread portion comprising the steps of: (a) transferring a tool in the direction of the X-axis to position the tool at the point where thread cutting is to be started; (b) transferring the tool in the direction of the Z-axis in synchronization with the rotation of the main spindle to cut threads in work; (c) performing a pullout operation by deceleration in the direction of the Z-axis and acceleration in the direction of the X-axis during a predetermined acceleration/deceleration time Ta so as to retract the tool in the direction of the X-axis; and (d) withdrawing the tool in the direction of the Z-axis to return the tool to the reference point of the thread cutting cycle. In the step (c) of the pullout operation, a command is issued concurrently with the start of the acceleration/deceleration time so as to realize a pullout speed Ve in the direction of the X-axis that exceeds an allowable maximum speed Vmax to increase the acceleration in the direction of the X-axis. The speed command directing the tool to move in the direction of the X-axis is maintained at the value of zero from the elapse of command time Te until the acceleration/deceleration time Ta expires so as to maintain the actual speed of the tool in the direction of the X-axis at or below the allowable maximum speed Vmax. | 09-08-2011 |
20110188958 | CUTTING METHOD - There is provided a cutting method for cutting a work by rotating a rotary tool with a circular cutting edge around an axis while a cutting fluid is supplied thereto. Cutting is performed by means of the rotary tool which is rotated in the same rotational direction as an outflow direction of chips, and the rotary tool is rotated at a rotational speed of the rotary tool at which a circumferential speed of the cutting edge is higher than an outflow speed of the chips. Thus, the area of direct solid contact between the rotary tool and the chips is reduced with the aid of a dynamic pressure effect, and the abrasion of the rotary tool is suppressed. | 08-04-2011 |
20110163221 | METHOD FOR CONTROLLING DEFLECTION IN STRUCTURAL MEMBER - A method for controlling deflection caused in a structural member when a force is applied to the structural member is described. The method includes a step of generating rotation torque in the structural member in such a direction as to cancel out the force applied to the structural member. The rotation torque is generated by a motor and a load inertia applying device such as a disc connected to the rotor. A stator of the motor is connected to the structural member and the load inertia applying device applies load inertia to a rotor of the motor. | 07-07-2011 |
20110156699 | MULTI-TURN ANGLE SENSOR - A multi-turn angle sensor includes rotors | 06-30-2011 |
20110135415 | VIBRATION SUPPRESSING DEVICE - In a vibration suppressing device provided in a machine tool having a rotary shaft for use in rotating a tool or a workpiece, for suppressing chatter vibrations generated during rotation of the rotary shaft, an arithmetical unit performs an analysis on a vibration of the rotary shaft detected by a detector (vibrations sensors) whenever the vibration is detected and a computation based on a result of the analysis. An operator, while checking results of the analysis and/or the computation displayed in real time in a display unit, manipulates a manipulation element to enter a command to change a rotation speed of the rotary shaft into a rotation speed control unit (NC unit) which controls the rotation speed according to the command entered by the operator through the manipulation element. | 06-09-2011 |
20110079121 | MACHINE TOOL AND BORING METHOD - In a machine tool ( | 04-07-2011 |
20110056343 | MACHINE TOOL - In a machine tool, a support member to which a headstock is mounted movably in an upward-downward direction is movable so as to change a position thereof in a horizontal direction relative to that of a bed. A guide member is provided on the bed and configured to guide the support member. An engageable portion at which the support member is supported by the guide member is located in the support member at a level within a range of upward-downward movement of the headstock along the support member. | 03-10-2011 |
20110040523 | METHOD AND PROGRAM FOR IDENTIFYING ERRORS - A method for identifying geometric errors with respect to at least two translational axes and at least one rotational axis of a machine using a control device is disclosed. The method comprises the steps of: measuring positions of a jig in three-dimensional space using a position measurement sensor, wherein a measurement is carried out when the jig being indexed around the rotational axis by a plurality of angles is located at the positions; approximating a plurality of measured values of the positions measured in the measuring step to a circular arc; and calculating an error in regard to a center position of the rotational axis and/or a tilt error in the rotational axis, and tilt errors in the translational axes, based on the circular arc resulting from the approximating step. | 02-17-2011 |
20110015050 | TOOL MAGAZINE - A tool magazine includes: a rotary shaft; and a plurality of tool gripping members radially extending around the rotary shaft. The tool magazine is configured to transfer tools between the tool gripping members and a tool attachment portion of a machine tool. The plurality of tool gripping members are arranged such that two tool gripping members are at least partially adjacent to each other and disposed in different heights in a direction of the rotary shaft, so that a tool is transferred between one of the two tool gripping members and the tool attachment portion without interference of the tool attachment portion against a tool gripped by the other one of the adjacent tool gripping member. | 01-20-2011 |
20100225180 | LINEAR MOTOR - There had been a problem that the installation area of a linear motor becomes large when a plurality of linear motors are arranged in parallel in the travel direction of a mover. | 09-09-2010 |
20100109594 | POSITION CONTROL APPARATUS FOR NUMERICALLY CONTROLLED MACHINE - In a position control apparatus that drives a feed-axis with a servomotor of a machine tool, the machine tool maybe quickly accelerated or decelerated in a state where a machine structural member that supports and fixes a structural member including a driving system has a lower rigidity, or in a state where an element having a lower rigidity is present beyond a load position where the detection by a linear scale is performed. In such cases, a generated deflection may induce a displacement in a mechanical system. A relative locus error may be generated between a workpiece to be processed and a front end portion of the tool. Further, a mechanism rigidity generally changes according to a machine posture. The generated deflection amount changes in magnitude. The present embodiment estimates and compensates a displacement amount of the front end portion of the tool that may be caused by the deflection of the mechanical system. Moreover, in calculating an estimation amount, the present embodiment can change a parameter corresponding to the mechanism rigidity based on the machine posture. Thus, the front end of the tool can move accurately along a desired locus relative to the workpiece to be processed. | 05-06-2010 |
20100104388 | VIBRATION SUPPRESSING METHOD AND VIBRATION SUPPRESSING DEVICE FOR MACHINE TOOL - A vibration suppressing method and a vibration suppressing device are disclosed. After a tool is attached to a main spindle, a modal parameter of the tool or a workpiece is computed. Thereafter, a relation between chatter frequency and phase difference is calculated as an approximation formula based on the obtained modal parameter and machining conditions. If chatter vibration occurs after initiation of the machining, a chatter frequency corresponding to a target phase difference is obtained using the approximation formula, and based on the obtained chatter frequency, the number of tool flutes and the main spindle rotation speed, the optimum rotation speed is calculated. The rotation speed of the main spindle is then changed in accordance with the obtained optimum rotation speed. | 04-29-2010 |
20100101383 | COMBINATION MACHINING LATHE - In a combination machining lathe, a workpiece holding device holds a workpiece in a manner that permits the workpiece to rotate around an axis parallel to a direction of a horizontal Z axis. A tool post holds a tool that comprises a holder and a bit. The tool held by the tool post is indexed to a position in which the longitudinal axis of the holder is parallel to an X axis direction. The bit of the tool held by the tool post is angled such that a longitudinal axis of the bit is disposed in a position tilted away from the X axis direction closer to a horizontal axis in a plane containing the X axis and the Y axis. A turning operation is performed while the tool and/or the workpiece are moved relative to each other in a direction of the longitudinal axis of the bit. | 04-29-2010 |
20100087948 | COLLISION PREVENTING DEVICE INCORPORATED IN NUMERICAL CONTROL APPARATUS - A collision preventing device includes an acceleration/deceleration simulating unit | 04-08-2010 |
20100039059 | MOTOR CONTROLLER - A motor controller is provided which has a function to prevent the falling of a shaft when the power supply to a motor is turned on. | 02-18-2010 |
20100010662 | VIBRATION SUPPRESSING METHOD AND DEVICE - A stable rotation speed is acquired by finely changing a rotation speed of a rotary shaft | 01-14-2010 |
20100005936 | CUTTING METHOD AND CUTTING APPARATUS - A tool main spindle, whose cutting angle can be changed, is translated by an X-axis moving mechanism portion on an X-axis provided in a plane perpendicular to an axis of a work; and is translated on a Y-axis by a Y-axis moving mechanism portion. Cutting of the work is performed by setting the cutting angle of the tool main spindle to an angle of the cutting tool at which the work has large dynamic rigidity, and causing an axis of a cutting tool to cross the work axis, and cutting the work with the cutting tool toward the axis of the work by cooperatively operating the X-axis moving mechanism portion and the Y-axis moving mechanism portion. | 01-14-2010 |
20090302796 | POSITION CONTROL APPARATUS - A position control apparatus includes a reverse displacement calculation unit configured to calculate a reverse displacement that represents an amount of movement made from a preceding reverse point to a current reverse point by an axis that performs a reversing motion; a reversing-time segmenting number calculation unit configured to compare the reverse displacement to a predetermined value, and, when the reverse displacement is less than the predetermined value, increase a value of a reversing-time segmenting number, which is a coefficient indicating a number of segments per unit time during a reversing motion, and, when the reverse displacement is greater than or equal to the predetermined value, decrease the value of the reversing-time segmenting number; and a quadrant inversion compensation unit configured to automatically adjust a quadrant inversion compensation amount according to the reversing-time segmenting number and perform the quadrant inversion compensation based on the automatically adjusted compensation amount. | 12-10-2009 |
20090240482 | MACHINING SIMULATION APPARATUS - A machining simulation apparatus ( | 09-24-2009 |
20090218893 | LINEAR MOTOR MOUNTING STRUCTURE - The present invention provides a magnetic attractive force-offsetting linear motor which prevents motor thrust from varying due to changes in the position on a stator, thus enabling improvement of the motor thrust and of the accuracy of the machine tool and the quality of a processed surface. A magnetic attractive force offsetting linear motor has a base | 09-03-2009 |
20090209398 | MACHINE TOOL - A machine tool includes a headstock provided with a main spindle and movable in a direction different from a direction of axis of the main spindle, a tool post mounted on the headstock so as to be movable in the direction of axis of the main spindle, and a tool change unit configured to change a tool attached to the main spindle with another tool after an extremity of the main spindle has been moved to a predetermined tool change position. In this machine tool, when an extremity of the tool post is positioned in the tool change position by the movement of the headstock and also by the movement of the tool post, the tool change unit performs change of a tool attached to the tool post with another tool by the same tool change operation as that for the main spindle. | 08-20-2009 |
20090199685 | TAILSTOCK CONTROL DEVICE - A tailstock control device supports an object to be machined by driving and controlling a servo motor which drives a driving system of a tailstock having a spring member in forward and backward directions, to cause a tailstock center connected to the tailstock to contact a center hole of the object to be machined. The tailstock control device comprises a limit torque value calculating unit which calculates, as a limit torque value (Tm), a drive torque value of the servo motor necessary for supporting the object to be machined, and a servo control unit which drives and controls the servo motor to attempt to move the tailstock at a tailstock movement velocity (Vs) which is set in advance, until an output torque value (Tr) of the servo motor reaches the limit torque value (Tm). The limit torque value (Tm) is calculated by subtracting, from the support thrust (Fa) necessary for supporting the object to be machined, an excessive thrust Fs which is calculated based on the tailstock movement velocity (Vs). | 08-13-2009 |
20090171594 | MACHINE DIAGNOSING METHOD AND DEVICE THEREFOR - A machine diagnosing device | 07-02-2009 |
20090112376 | POSITION CONTROLLING DEVICE - A structure is provided in which a thrust feed forward structure for operating a structure to be driven without vibration and a control structure which simultaneously compensates for positional deviation caused by the thrust feed forward structure and positional deviation caused by a base displacement are included in a position controlling device ( | 04-30-2009 |
20090112356 | NUMERICAL CONTROL APPARATUS WITH MANUAL SHIFT OPERATION FUNCTIONALITY - A numerical control apparatus provides for manual shift operation involving feed shafts of a machine tool in terms of a work coordinate system easily and readily understood by an operator. The numerical control apparatus includes a manual shift amount input unit for receiving an amount of manual shift involving linear feed shafts as operator-input data in terms of a work coordinate system defined on the work revolved or rotated by a rotary feed shaft. The numerical control apparatus further includes a manual shift amount cumulative storage for cumulatively storing the received amount of manual shift in terms of a work coordinate system. Also included is a cumulative shift amount coordinate converter for converting the cumulative amount of shift from the work coordinate system data to data in terms of machine coordinate system defined on the machine tool. The apparatus's manual shift amount superimposing unit then superimposes the converted cumulative amount of shift on a controlled variable commanded in a machining program to generate the result to servo drivers. | 04-30-2009 |
20090110499 | METHOD FOR SUPPRESSING VIBRATION AND DEVICE THEREFOR - The vibration suppressing device includes vibration sensors, a FFT calculating unit, a store device, a calculating unit, and a NC device. The vibration sensors detect a time-domain vibrational acceleration of a rotary shaft during rotating. The FFT calculating unit calculates a frequency of chatter vibration and a frequency-domain vibrational acceleration in the frequency of chatter vibration on the basis of the detected time-domain vibrational acceleration. The store device stores the frequency-domain vibrational acceleration, the frequency of chatter vibration and the like as machining information. When the calculated maximum frequency-domain acceleration exceeds a predetermined threshold value, the calculating unit stores the maximum acceleration, the frequency of chatter vibration, and the like as current machining information in the store device, and calculates an optimal rotation speed of the rotary shaft, by which the chatter vibration can be suppressed, based on the current machining information and previous machining information stored in the store device. The NC device rotates the rotary shaft at the optimal rotation speed. | 04-30-2009 |
20090082900 | NUMERICAL CONTROLLER OF MACHINE TOOL - A numerical controller having a function-generating unit which executes function generation for shaft movement according to a machining program is provided, the numerical controller further comprising a unit which stores shape data of the movable unit and shape data of an interfering structure; a retracting direction determining unit which determines a retracting direction; an interference checking position calculating unit which successively calculates, as an interference checking position, a position in which a desired distance is added to the current position of the movable unit according to the determined retracting direction; an interference confirming unit which confirms presence or absence of interference between the shape data of the movable unit and the shape data of the interfering structure by virtually moving the shape data of the movable unit; and a power outage detecting unit which sends a power outage signal to a DC power supply unit and the function-generating unit during power outage, wherein the function-generating unit executes function generation according to a result of the interference confirming unit. | 03-26-2009 |
20090069927 | VIBRATION SUPPRESSING DEVICE FOR MACHINE TOOL - A calculating member carries out Fourier analysis of a vibrational acceleration to calculate a maximum acceleration and frequency thereof. The calculating member then compares the maximum acceleration with a threshold value, and when the acceleration exceeds the threshold value, the calculating member calculates a k-value and phase information, and stores each calculated value. When retrying is selected, the calculating member determines a type of a current chatter vibration from the phase information, determines the existence of a chatter vibration which is different from the determined chatter vibration, and calculates each new phase information according to the determined chatter vibration and an existence of a different chatter vibration which had been generated before generation of the current vibration. The calculating member then calculates a k1-value from new phase information, calculates the optimum rotation speed by using the k1-value, and changes the rotation speed to the optimum rotation speed. | 03-12-2009 |
20090026997 | CONTROL APPARATUS FOR RELUCTANCE TYPE SYNCHRONOUS MOTOR - A control apparatus for a motor (in | 01-29-2009 |
20090000907 | PALLET EXCHANGER - A pallet exchanger capable of providing a sufficient operation space on an operator's access side, for example, in front of a machining space, without increasing the size of the exchanger is provided. | 01-01-2009 |
20090000441 | CUTTING METHOD - An object is to provide a cutting method capable of efficiently removing cutting chips around a cutting point with a little electric power, and cutting a work with high accuracy. | 01-01-2009 |
20080289923 | VIBRATION SUPPRESSING DEVICE AND VIBRATION SUPPRESSING METHOD FOR MACHINE TOOL - A vibration suppressing device and a vibration suppressing method that are capable of obtaining an accurate optimum rotation speed and shortening a time period from generation of chatter vibration to calculation of the optimum rotation speed are provided. The vibration suppressing device | 11-27-2008 |
20080267749 | PALLET TRANSFER SYSTEM - A pallet transfer system capable of smoothly transferring a pallet between a machine tool and a pallet conveying device is provided. | 10-30-2008 |
20080249653 | NUMERICAL CONTROL UNIT - A numerical control apparatus with a single block function is provided including a start button ( | 10-09-2008 |
20080231266 | ABSOLUTE ENCODER - A printed circuit board on which are laid out detection windings and an excitation magnetic flux detection winding formed of conductor patterns is disposed so as to be spaced a predetermined gap quantity from a binary cyclic random number sequence code plate which is rotatably disposed. A U-shaped exciting core on which an excitation winding is wound is disposed on the back surface side of the printed circuit board. The detection windings detect and output, as voltage values, reluctance changes as which excitation magnetic fluxes generated from the excitation winding fluctuate between this excitation winding and the concave/convex portion of the binary cyclic random number sequence code plate. Reduction of precision due to interferences between the excitation magnetic fluxes for detecting an absolute code and other excitation magnetic flux is thereby prevented. | 09-25-2008 |
20080231265 | POSITION DETECTOR WITH TILT SENSOR - A scale section is made of a magnetic material. A repeated pattern is recorded at a uniform pitch on the surface of the scale section. A sensor section is provided independently from the scale section. The sensor section is provided with a magnetic position sensor that reads the pattern, on a surface close to the surface of the scale section. Further, the sensor section is provided with a magnetic tilt sensor that detects a tilt between the surface of the scale section and the surface of the sensor section on which the position sensor is located. The magnetic position detector in which the scale section and the sensor section are separated from each other can be efficiently fixed to a detection target using the tilt sensor. | 09-25-2008 |
20080228423 | POSITION DETECTOR - Two position sensors provide, as outputs, two signals that vary sinusoidally at a pitch of wavelength λ with respect to a displacement of a target and have phases shifted from each other by 90°. A memory unit has stored therein offset values for the two signals, and two subtractors eliminate the offset values from the two signals, respectively. The two signals after offset elimination are converted into position data in an interpolation calculator. A radius calculator calculates a radius value of the two signals after offset elimination. An FFT calculates offset values based on the position data and the radius values, and the calculated offset values are used to update the values stored in the memory unit. An amplitude ratio correction value and a phase difference correction value for the two signals are updated similarly. By performing elimination of the components that degrade interpolation accuracy at every rotational position, interpolation accuracy is improved. | 09-18-2008 |
20080224693 | ABNORMALITY DETECTION APPARATUS FOR ROTARY TYPE ABSOLUTE ENCODER - In order to cope with many rotor diameters using a single type of stator portion, two stator portions, each having a built-in signal processing circuit for detecting absolute positions independently, are disposed in opposition at positions which differ from each other with respect to a rotational center of a rotor portion. When one of the stator portions receives a request command RX from an external device, it transmits a detected serial communication signal. The other stator portion receives the transmitted serial communication signal, determines a position detection abnormality, and notifies the abnormality to the external device when a difference between the received absolute position and the absolute position detected by the other stator portion exceeds a deviation previously set for 180 degrees. | 09-18-2008 |
20080222834 | WIPER | 09-18-2008 |
20080215178 | METHOD FOR ESTIMATING THERMAL DISPLACEMENT IN MACHINE TOOL - After a thermal displacement correcting program has started, a temperature is measured with a temperature sensor in S | 09-04-2008 |
20080203959 | SERVO MOTOR CONTROLLER - A controller includes a rotating direction detecting unit | 08-28-2008 |
20080202297 | TURRET TOOL REST AND MACHINE TOOL - A turret tool rest | 08-28-2008 |