Abstract: A numerical control unit includes a program creating device (TPC) having an input device (104) for entering data for the creation of a machining program. A processor (101) creates a machining program in accordance with the entered data, and a memory (103) stores the created machining program. The numerical control unit also includes a machine control device (NCC) having a memory (203) for storing a machining program transferred from the memory (103), and a processor (201) which executes the machining program stored in the memory (203) to numerically control a connected industrial machine (MAC). By using this numerical control unit creation of a machining program and control of the machine may be carried out concurrently. The numerical control unit also includes a switching circuit (301) for selectively connecting an external unit (IOC) to the program creating device (TPC) or to the machine control device (NCC), thereby making it possible to preserve a machining program in the external unit (IOC).

Abstract: A tool display system of an automatic tool changing apparatus (31) in a machine tool (30) sequentially controlled by a programmable controller (20) on the basis of a control signal from a numerical control unit (1). The tool display system is equipped with a memory (21) for storing the positions of a plurality of pots (31b) provided on a tool magazine (31a) accommodating tools, and a display unit (14) for displaying the tool information stored in the memory (21). The display unit (14) displays a graphic pattern representing the positions of the plurality of pots on the tool magazine (31a) as well as the present positions of tools accommodated in the tool magazine, the latter appearing inside the graphic pattern.

Abstract: The present invention increases screw cutting accuracy and simplifies the control of a screw cutting control system which performs screw cutting through the use of a numerically-controlled machine tool. A tapper (TPP) connected to a spindle, holds a tap (TAP) in a manner to be movable in the axial direction of the spindle, transmits the rotation of the spindle to the tap (TAP) for a predetermined range of forward axial movement of the tap (TAP) and transmits the rotation of the spindle to the tap (TAP) when the spindle is reversed. During screw cutting, feed by a feed motor (SZ) stops after the tap (TAP) enters a workpiece and the screw cutting is effected by the thrust of the tap itself resulting from the rotation of the spindle. The sequence of screw cutting is commanded by one block of command data.

Abstract: A method of diagnosing a servomotor position control circuit which includes a pulse distributor for carrying out arithmetic operations for pulse distribution based on command data given by a control unit, a position detector for generating a positional pulse each time the servomotor rotates through a predetermined angular interval, an error storage unit for computing and storing the difference between the number of positional pulses generated by the position detector and the number of distributed pulses generated by the pulse distributor, and a D/A converter for converting the difference into an analog output, whereby the servomotor is controlled by the analog output from the D/A converter.

Abstract: A method and apparatus for numerically controlling a machine tool having at least two tools which are arranged to move in unison with a constant position relationship with respect to one another, the tools being moved relative to a workpiece in accordance with absolute commands to machine a workpiece in a prescribed manner. A single current position register, comprising a section for storing X coordinates and a section for storing Z coordinates, is provided to store the current position of a first tool. Further provided are arithmetic means, responsive to a command for setting coordinates, for computing the current position of a second tool, as well as pulse distribution means.

Abstract: A method for rotating a workpiece at a constant peripheral speed when the workpiece is cut as on a lathe. Before a cutting tool is moved to a cutting position under a rapid-advance command, the number n of RPM for the spindle is computed from the following equation, based on the distance x between the cutting position and the axis of the spindle and based on the commanded periphery speed V for driving the spindle at the computed number of RPM thereof:n=V/2 xAccordingly, the actual peripheral speed of the spindle becomes the same as or approximates the commanded peripheral speed when the cutting tool reaches the cutting position.

Abstract: A feed speed control system for use in numerical control systems or the like, in which a set feed speed can be adjusted through a simple structure. The control system includes a memory circuit for storing a plurality of numerical values corresponding to feed speeds, a command circuit for issuing a command indicative of a prescribed numerical value from among the plurality of numerical values, an arithmetic circuit for incrementing or decrementing a numerical value read from the memory circuit in response to an output pulse from manual operation device, and a pulse generating circuit for generating pulses of a frequency which is proportional to an incremented or decremented numerical value from the arithmetic circuit.

Abstract: A method and system for transmitting N-bit serial data (where N is a positive number) in the form of a bit serial, including a data sending circuit, a data receiving circuit and data transmission lines. The system includes a first data transmission line; a second transmission line; a transfer circuit, provided in the receiving means, for sending back to the data sending circuit through the second data transmission line, the bit content of received N-bit data each time one bit of the N-bit data is received through the first data transmission line; a comparison circuit, provided in the data sending circuit, for comparing the transmitted bit content and the bit content sent back on the second data transmission line; and a detection circuit provided in the data receiving circuit. The data sending circuit is adapted to transmit as a start bit a signal of a prescribed logical value before the N-bit serial data is sent, and, as an alarm bit, the results of the comparison after the N-bit serial data has been sent.

Abstract: When machining with a numerical-controlled machine tool, both a command value providing the configuration of a finished product and a compensation value depending on the tool are needed, and tool compensation data must be corrected in response to tool wear. The present invention, taking notice of the fact that correction data corresponding to tool wear can be predetermined from the frequency or time of tool use and the fact that the amount of tool wear can be unequivocally determined by the quality of materials of the tool and work, provides circuitry for counting the frequency or time of use of the tool and circuitry for correcting by a predetermined value the content of a compensation value register having tool compensation date when the number of times a tool has been used or when the duration of tool use has reached a predetermined value.

Abstract: In a numerical control unit which has an interpolation function from generating command pulses in response to a distribution command and a servo system for driving a movable part of a machine in accordance with command pulses, a comparison is made between the error of the servo system a predetermined period of time after the distribution command is switched off and a preset value; when the error of the servo system is larger than the predetermined value, an alarm signal is produced to detect the occurrence of a malfunction.

Abstract: A positioning system in a numerically controlled apparatus in which a position of a controlled object such as table and tool is controlled by command pulses delivered from the numerical control apparatus. The positioning systemGenerates first pulses every time the controlled object moves a first predetermined amount;Generates second pulses every time the controlled object moves a second predetermined amount larger than the first predetermined amount, and;Detects the moving amount of the controlled object. A counter which has a capacity equivalent to the number of the first pulses generated while the object moves the second predetermined amount and which is set with a position error of the controlled object corresponding to the difference between the number of command pulses and that of the first pulses when the second pulses are generated at least one time, and counts the command pulses after being set with the position error.