Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A plurality of coils C1 to Cm that constitutes a whole winding L of each phase is divided into g coil groups G1 to Gg for each phase. Each coil group is, for example, constituted by coils C1 to C4 wound around four polar teeth continuously disposed. The number of turns of respective end coils C1 to C4 of the coil group is less than the number of turns of central coils C2 and C3. Further, the whole winding L includes n partial windings N1 to Nn, in which a coil Cj (j is an integer in the range from 1 to m) is constituted by n sub coils S(1,j) to S(n,j) that are formed by the n partial windings. It is feasible to set a non-integer value as an effective number of turns of a coil when the number of turns of each sub coil is appropriately selected.

Abstract: A spindle attachment includes a device body having an attachment surface detachably attached to an end face of a spindle head. Fixed and movable teeth move the body in a direction of an axial line of the spindle to engage the spindle head and the body so as to freely restrict or release rotation of the body with respect to the spindle head. A coil spring urges the body so that the attachment surface is pressed onto the end face of the spindle head with the fixed and movable teeth ready for engagement. A pressure cylinder causes fluid pressure to act on the attachment surface against the spring force to release engagement between the fixed and movable teeth. A key and a key groove transmit rotation of the spindle to the body with the fluid pressure of the cylinder acting on the attachment surface of the device body.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A multi-turn angle sensor includes rotors 60, 62, 64, each of which rotates in a different manner with respect to an input shaft 19, and a common stator portion 66. The rotors and pole teeth disposed around the rotors form each of resolvers 600, 620, 640. At least two of the resolvers are arranged on a single plane vertical to the rotation central axis of each of the rotors. The common stator portion 66 surrounding each of the rotors is formed by laminating electromagnetic steel sheets 106, each of which has an identical shape including a plurality of sets of pole teeth corresponding to each of the rotors. A single length of unspliced electrical wire is wound around each of the pole tooth sets. This facilitates automation of assembly.

Abstract: An acceleration command calculator 22 calculates an acceleration command “as” based on an output torque Tmb of the spindle motor applied when the rotational speed is less than or equal to a base rotational speed and an inertia Jm+Jl of the overall spindle. A switching speed calculator 23 calculates a control mode switching speed Vs based on the acceleration command “as”. A control mode switching switch 5 switches from a speed control mode to a position control mode when the motor speed Vm becomes less than or equal to the control mode switching speed Vs, to stop the spindle at a desired rotational position. The control mode switching speed Vs may be a value calculated using the following equation: Vs=60×(amax×0.5)1/2, where a maximum acceleration that can be achieved at this time is represented by a max.

Abstract: A control device which controls a servo motor of a machine tool in the event of power failure is provided.

Abstract: A method includes: (a) transferring a tool to where thread cutting is to start; (b) cutting threads in work with the tool; (c) performing tool deceleration along the Z-axis and acceleration along the X-axis during a predetermined acceleration/deceleration time Ta to retract the tool along the X-axis; and (d) returning the tool to a reference point. In Step (c), to shorten the incomplete thread portion, a command is issued concurrently with the start of the acceleration/deceleration time Ta to realize a pullout speed Ve along the X-axis that exceeds an allowable maximum speed Vmax to increase the acceleration along the X-axis. The speed command for moving the tool along the X-axis is maintained at the value of zero from the elapse of command time Te until the acceleration/deceleration time Ta expires to maintain the actual speed of the tool along the X-axis at or below the allowable maximum speed Vmax.