Abstract: A feed speed control method for a numerical control device in which a feed speed of a tool traveling along an instructed machining path is controlled in accordance with a machining program. The speed of each axis is derived (S2), and the acceleration of each axis is derived from a speed variation between adjacent blocks (S3). When the acceleration (.DELTA.Vx) is larger than a permissible acceleration (.DELTA.Vxmax) (S4), first ratios (K1) of the permissible accelerations to the accelerations are derived for individual axes (S5), and the smallest of the first ratios is selected. The command speed is multiplied by the square root of the smallest first ratio to derive an actual feed speed (S9). In this way, shock to a machine is reduced and an excessive load on a servomotor is reduced even when blocks continue for successive infinitesimal distribution distances, as in the case wherein a curve is approximated by the use of straight lines.

Abstract: A spindle control command method is provided for controlling a plurality of spindless by a single numerical control device (CNC), and switching between individual control and synchronous control of a plurality of spindles (1, 3) is effected by a program command (9). Namely, whether the spindles (1, 3) should be controlled individually or synchronously is commanded by an NC program (9), and the CNC carries out switching to the individual spindle control or to the synchronous spindle control in accordance with the command given.

Abstract: A method of correcting a change of position of a machine tool having at least two control axes avoids abrupt machining errors. A position correction means (12) outputs correction pulses (Xcp, Ycp) so that the ratio of actual amounts of movement of the respective axes, obtained from the output values of position detectors (8X, 8Y) detecting a position of the machine tool, becomes equal to the ratio (R1) of distribution pulses (Xp1, Yp1) for the respective axes. The correction pulses (Xcp, Ycp) are added to the distribution pulses (Xp1, Yp1). Accordingly, an abrupt machining error caused at the beginning or just before the end of machining, or when machining a corner of a workpiece, is alleviated.

Abstract: NC programs (11a-11d) are provided for corresponding ones of movable elements for prescribed axes, and the movable elements are moved by performing numerical control processing in numerical controllers (12a-12d) based on the NC programs. A plurality of axes to be synchronously controlled are designated by a synchronous axis command (SANC) inserted in the main NC program (11a), queuing commands (WNC) are inserted in the NC programs conforming to the movable elements which include the designated axes, and the corresponding movable elements are moved and controlled by performing numerical control processing while synchronization is achieved by the queuing commands.

Abstract: Disclosed is a numerical control apparatus for controlling a chopping operation of a tool used in a grinding machine and the like. A programmed instruction value calculation circuit (2) outputs an upper dead point instruction (Zu) and a lower dead point instruction (Zl), a correction value calculation circuit (3) calculates and outputs correction values (.DELTA.Zu, .DELTA.Zl), and a chopping instruction calculation circuit (4) outputs a chopping control output to a manual control circuit (6) based on these instructions and correction values to operate a servo motor. When an instruction value (Zi) is input from a manual pulse generator (5) to the chopping instruction calculation circuit (4), the chopping is effected while continuously changing the upper and lower dead points, thereby enabling an operator to easily adjust the upper and lower dead points.

Abstract: A position correcting system is incorporated in a machine tool having a plurality of workpiece machining positions. A control block (80) has a position correcting register (81) for storing position correctives corresponding to the respective workpiece machining positions. Distributed data (X1, Z1) are calculated from a machining program (71) by a pre-processing means (72). The position correctives (.DELTA.X1, .DELTA.Z1) are added to the distributed data (X1, Z1) by an adder (82), which outputs position commands for machining heads corresponding to the workpiece machining positions. In response to the position commands, an interpolating unit (83) carries out pulse interpolation and produce output pulses. Such control blocks (80, 90, 100) are associated with the respective machining heads. Errors between the workpieces and the machining heads are corrected in all the machining positions, so that the workpieces can be machined with accuracy.

Abstract: Provided is a numerical control method in an apparatus having a C-axis control function for numerically controlling a spindle in the direction of rotation. The method includes providing a first G-code word (Gg1) for achieving agreement between axis control characteristic values of a C-axis motor control system and axis control characteristic values of a feed-axis motor control system, as well as a second G-code word (Gg2) for restoring axis control characteristic values changed by the first G-code word to original values, making spindle control characteristic values agree by commanding the first G-code word before controlling the C axis at the same time as the feed axis, and restoring to original values the spindle control characteristic values changed by the first G-code word by commanding the second G-code word after simultaneous control of the C axis and feed axis ends.

Abstract: A system for reloading pitch error correction data at the time of replacing a movable part constituting part of a mechanical system of a numerically controlled machine tool. A command to reload the pitch error correction data is preset in a machining program at the time of replacing the movable part. A numerical control device reads this command. If a parameter reload command is given (S1), and if it is the pitch error correction data (S2), it is determined whether the movable part is situated at the original position (S3), and the pitch error correction data is automatically reloaded (S4). Accordingly, the operator is not required to carry out any operation related to the reloading of the pitch error correction data, and thus the machining can be effected with the use of correct pitch error correction data.

Abstract: A computerized numerical control system controls the axes of a computerized numerical control apparatus (20) from a programmable machine controller (10) coupled to the computerized numerical control apparatus (20). Command values for the axes, information with respect to the grouping of the axes, and execution times for the axes in respective groups are sent from the programmable machine controller (10) to the computerized numerical control apparatus (20). When all commands for the axes in the respective groups are received by the computerized numerical control apparatus (20), pulses start to be distributed to the axes, and the pulses are distributed within the execution times. Linear interpolation can be performed on any desired combination of axes of the computerized numerical control apparatus (20) for preventing physical interference which could otherwise occur between axes when an automatic tool changing (ATC) mode is controlled by the programmable machine controller (10).

Abstract: A CNC method controls a plurality of paths with a single computerized numerical control apparatus. In the CNC method, an order (6) in which to execute part programs (5) for the respective paths (4) is designated, and the part programs (5) are sequentially executed in the designated order. The contents of the part programs (5) can thus be checked for each of the part programs.

Abstract: Disclosed is a spindle control system of a numerical control apparatus capable of independently controlling a plurality of spindles by a plurality of paths. Connecting relationships between respective paths (11 to 14) and respective spindles (61 to 65) are defined in a region (3), the content of the region (3) is changed by a machining program to change the spindles (61 to 65) to be controlled by the respective paths (11 to 14), whereby a more effectively machining can be realized.

Abstract: An involute interpolation method for a computerized numerical control apparatus having a rotational axis and a linear axis is effected by giving commands for a direction in which an involute curve (IC) rotates, the position of the center of a base circle (BC), and the radius (R) of the base circle, and interpolating the involute curve (IC) according to the commands. Interpolated distances are converted to those along the rotational axis and the linear axis for the control of a machine tool (9).

Abstract: An involute interpolation method for a computerized numerical control apparatus having a rotational axis and a linear axis is effected by giving commands for a direction in which an involute curve (ICl) rotates, the position of the center of a base circle (BC), the radius (R) of the base circle, and a Z-axis, and interpolating the involute curve (ICl) and the Z-axis according to the commands. Interpolated distances are converted to those along the rotational axis, the linear axis, and the Z-axis for the control of a machine tool (9).

Abstract: A numerical control system controls a plurality of axes with a plurality of channels (10, 20, 30). When a machining program for a first channel (10) is interrupted after a single block in response to a single block signal (6), the feeding of commands of a machining program for other channels (20, 30) is held. The machining programs are thereby executed in synchronism with each other. The machining processes are prevented from being unbalanced, and machining interference is avoided.

Abstract: An axis changeover apparatus according to the invention changes axes of movement of a machine tool having axes with the same direction of movement, such as a cross rail axis and quill axis. A check is performed to determine the commanded strokes along axes (Z and W axes) from machining commands supplied by an NC command tape (1). If a move command has a commanded stroke which exceeds a set limit stroke value, the portion of the commanded stroke which exceeds the value is converted into a commanded stroke along the other axis having the same direction of movement, thereby elongating the apparent stroke.

Abstract: An acceleration/deceleration control apparatus according to the present invention is utilized in a numerical contorl unit in which a machine tool is provided with a machining program from a command tape (3) and the machining program is decoded to simultaneously control movement along a plurality of axes. In order to eliminate machining trajactory sag which occurs at the breaks between program blocks, the actual velocity of a controlled object during deceleration is compared with the commanded velocity in the next command data block by a comparator circuit (7). Until the actual velocity is less than the command velocity, a pulse distribution circuit (6) is stopped so as not to perform pulse distribution based on the next command data block. This improves the accuracy of position control by servomotors (1), (2) the acceleration/deceleration of which is controlled by interpolation data.

Abstract: A numerical control apparatus according to the invention has a mode designating interface for deciding a control mode and an interface which receives position and velocity commands, these interfaces being interposed between the apparatus and a servo-processor. A mode for controlling the servomotor is automatically decided internally of the numerical control apparatus. Changeover is possible in which the servomotor is used as a motor for positional control or in order to control rotational velocity in the manner of a spindle motor to achieve continuous rotation.

Abstract: A numerical control apparatus according to the invention for interpolatory control of a tool along the shape of a workpiece to be machined. In order to perform offsetting of a cutting tool by an amount equivalent to the tool diameter when involute interpolation is carried out, an involute curve is approximated by a circular which is set in dependence upon the intersection angle of a machining trajectory at a command point commanding the start of machining.

Abstract: A numerical control method is provided, which is capable of uninterruptedly conducting control, at high speed, in accordance with various kinds of NC program. Command information stated in each of blocks of the NC program is read out and decoded by a first sub-CPU to prepare an intermediate data which is to be stored in a first shared RAM. This intermediate data is converted into data of execute form by a second sub-CPU and is stored in a second shared RAM. Preparatory processings for two blocks, each starting from the reading operation of the command information and ending at the preparation of the execute form data, are conducted simultaneously, so that a time period required for execution of each preparatory processing is shortened in apperance, to thereby prevent interruption of the numerical control due to a delay in the preparatory processing.

Abstract: An involute interpolation method is provided for machining operations in a numerical control apparatus, in which a rotational direction of an involute curve, a center position of a base circle (C), and a radius (R) of the base circle (C) are instructed, and an interpolation is performed with respect to an involute curve having a start point (P.sub.s) on a first involute curve (IC1) and an end point (P.sub.e) on a second involute curve (IC2). According to such a method, machining operations can be done by the use of a specifically configured involute curve which is distinct from the two involute curves.