Abstract: A machining center equipped with an integral robot device having a manipulating hand capable of approaching a spindle of the machining center, a tool storing magazine mounted on a machine body, a workpiece supply table disposed on a floor in the vicinity of the machine body, and a work table of the machine body so that an exchange of cutting tools may be carried out by the manipulating hand between the tool storing magazine and the spindle, and so that an exchange of workpieces may also be carried out by the manipulating hand between the tool storing magazine and the work table.

Abstract: A control system for stopping a spindle at a predetermined rotational position, for driving a spindle in such a manner that a positional deviation between the present rotational position of a specified point on the spindle and a predetermined rotational position at which the specified point is to be stopped, is reduced to zero, thereby to stop the specified point on the spindle at the predetermined rotational position. First and second rotational position sensors are attached to the spindle at first and second specified points thereof, the position at which at least the first rotational position sensor is attached being adjustable. Further provided are changeover means and an orientation control circuit. The first position sensor produces a rotational position deviation signal when a tool is inserted into and withdrawn from a workpiece at the time of a boring operation, and the second position sensor produces a rotational position deviation signal when tools are changed.

Abstract: In a character display in which dot data is read out, by a character address and a row address, from a character generator having stored therein each character in the form of dots and applied to a display unit in synchronism with dot clock pulses to provide a display of the character. There are provided means for frequency dividing the dot clock and character clock pulses and means for controlling the step-by-step advancement of the row address, whereby a character display of a desired size is provided.

Abstract: In one forward or backward trace path on a model, a jerk point in the surface configuration of the model is detected and the position of the jerk point is stored in a memory. The reduction of the trace velocity is started a predetermined distance short of the stored position of the jerk point in the trace direction and when a jerk point is detected again, the position of the jerk point previously stored in the memory is updated and the reduction of the trace velocity is released, thus achieving high accuracy trace.

Abstract: A vertical-type machining center having a spindle carrier which travels in the vertical direction and a turret capable of both rotation and upward and downward movement provided on the spindle carrier, wherein tools are automatically changed over through rotation of the turret caused by relative movement between the turret and the spindle carrier when the upward movement of the turret is checked by a restraining member. A Z-axis position pulse generator is provided on a spindle mechanism drive member, such as the vertical drive motor or a screw shaft, and is adapted to generate a pulse for each revolution of the drive member. The pulses are counted by a counter which delivers a counted value for use in computing the vertical position of the spindle mechanism. The arrangement is such that the rotational speed of the vertical drive motor is controlled so as to move the spindle mechanism at an optimum speed suitable for the vertical position thereof.

Abstract: In a tracer control system, parameters necessary for a trace operation, such as, for example, tracer head reference displacement value, trace axis, trace direction, pick feed value, and various limits, are set in combination for each trace mode. A character display is provided for displaying various parameters, so that it is easy to confirm each of the required parameters corresponding to a selected trace mode, and check whether the setting of all required parameters has been completed or not and whether the value of each set parameter is the desired one or not.

Abstract: In a system which performs tracer control by calculating the direction and the velocity of tracing through utilization of signals from a tracer head tracing the model surface, there are provided an input unit for entering data defining the tracing operation, a memory for storing the data and processor for reading out the data from the memory to control respective parts of a control device. Data concerning clamp tracing is read out by the processor to change the clamp level by a predetermined value for each working, thereby performing repetitive clamp tracing.

Abstract: An improved control system for facilitating tapping work in a machining center of the type which performs a variety of machining operations automatically. Control is effected by establishing and maintaining a certain relationship between the operation of a spindle motor which rotates a tap, and the operation of a Z-axis feed motor which transports a table longitudinally of the tap, the table mounting a workpiece. Specifically, the spindle motor and Z-axis feed motor are driven in relation to one another at all times in such a manner that the equation N.sub.s =f.sub.m /P will be satisfied, where N.sub.s (rpm) is the rotational speed of the spindle motor, f.sub.m is the feed speed of the table along the Z-axis, and P is the thread pitch of the tap. Apparatus for controlling the spindle motor includes a control circuit which is adapted to stop the spindle at a prescribed angle of rotation.

Abstract: An industrial robot having two rotative mechanisms that are adapted to rotate two arms relative to the axial directions thereof and which are interconnected such that their longitudinal axes intersect at right angles. An arm which belongs to the first rotative mechanism is secured to the base of the robot, and a gripping member is attached to the end of a free arm which belongs to the second rotative mechanism. This permits the gripping member to be moved in a plane which is parallel to the X-Z plane, and then in a plane which is parallel to the Y-Z plane, so that a workpiece or tool replacement can be moved along the perpendicular side walls of a machine tool frame.

Abstract: An apparatus for controlling the operation of an AC motor wherein braking energy at the time of a reduction in motor speed is disposed of by regenerative braking. The apparatus includes a rectifier connected to the AC power source, a smoothing capacitor, a variable-voltage variable-frequency inverter, and a regenerative thyristor bridge circuit connected between the inverter and the rectifier through switching transistors. There is also provided a firing control circuit for controlling the firing of each thyristor in the thyristor bridge circuit and for controlling driving of the switching transistors in synchronism with the firing of the thyristors, the braking energy being fed back to the AC power source when the AC motor undergoes a reduction in speed. The apparatus is small and can be constructed simply and inexpensively.

Abstract: A method and apparatus for correcting an error in a position sensing circuit employing a resolver, an Inductsyn (trade name) or the like. Accurate position sensing is not possible in a position sensor using a resolver or the like when the electromagnetic coupling between the secondary winding and a cosine excitation coil is different from that between the secondary winding and a sine excitation coil. To eliminate a position sensing error caused by such a disparity in electromagnetic coupling, the present invention varies an electrical angle .alpha.

Abstract: A numerical control system comprising a numerical control device, a machine tool for machining a workpiece under the control of the numerical control device, and a robot for executing various tasks such as mounting the workpiece on the machine tool or demounting the workpiece therefrom. The numerical control device, in addition to the hardware which it possesses for controlling the machine tool, is further provided with a teaching control panel, a heavy current circuit which handles the exchange of data between the numerical control device and the robot, and a switching control circuit for switching over the output side of a pulse distributing circuit so that the pulse distributing circuit can be used in controlling both the robot and the machine tool. Machining data for control of the machine tool and data for commanding the robot are stored in a memory device incorporated in the numerical control device, or in a storage medium which is located externally of the system.

Abstract: A spindle orientation control apparatus having a motor for driving a spindle, speed control means for rotating the spindle at a speed in accordance with a command speed, and position control means for stopping the spindle at a commanded stopping position. The apparatus is further provided with stopping position command means for digitally instructing the spindle stopping position, a position sensor, error monitoring means for monitoring an error between the commanded stopping position and the actual rotational position of the spindle and for generating a signal when the error attains a predetermined value, and means for generating a signal indicative of an orientation speed. When the apparatus is in a spindle orientation control mode, the spindle is speed-controlled so as to rotate at the orientation speed until the error monitoring means generates said signal, and is position-controlled after the generation of the signal so as to reduce the error to zero.

Abstract: A wire or band electrode type electric discharge machine for machining hard metals by an electric spark generated between the metal workpiece and a wire electrode which is fed longitudinally to provide a fresh supply thereof while a prescribed relative motion is established between the workpiece and the wire electrode. The invention provides a clamping mechanism on the wire supply side of the workpiece for clamping the wire electrode if it breaks during operation, and a wire electrode feed mechanism for automatically guiding the broken end of the wire through the opening that has been machined in the workpiece. A wire electrode pull-up mechanism is provided on the other side of the workpiece for gripping and pulling up the wire electrode. If the electrode wire breaks during a machining operation, the clamping mechanism immediately clamps the wire electrode and prevents it from falling under its own weight.

Abstract: Teach data for directing the operation of an industrial robot is entered from a teach operating panel and set in a teaching memory. Machine work identify, insufficient machine work detect and other similar external data and data, such as the current and teach positions of the robot, are set in a work memory. A processor accomplishes write/read control of the teaching memory and the work memory and processing of the various data. In accordance with the result of processing by the processor, the robot is controlled and, in accordance with the contents of the external data, the teach data or the sequence by which the teach data controls is modified, thereby to efficiently operate the robot.

Abstract: A control system for rigidly stopping the spindle of a machine tool at a prescribed angular position when a tool is to be changed, without the use of a mechanical brake. Provided for this purpose is an orientation control circuit adapted to produce an output signal of zero potential when the spindle is at a prescribed stopping position, and an output signal of a potential proportional to the amount of angular deviation when the spindle is displaced from the prescribed stopping position. To stop the spindle at a prescribed stopping position, the output signal from the orientation control circuit is delivered in place of a speed command signal to a speed control loop of the type which limits to zero the difference between the speed command signal and a speed feedback signal. When the spindle is at rest, the feedback function of the speed control loop holds the rotary shaft of the spindle motor rigidly at the stopping position as if a mechanical brake were applied thereto.

Abstract: In a power source for a wire-cut, electric-discharge machine, a plurality of capacitors of different capacitances are provided as the discharge capacitors in a transistor-capacitor circuit and the capacitors are selectively used in accordance with the machined surface of the workpiece. Each capacitor has connected thereto an inductor, the inductance value of which increases as the capacitance value of the capacitor decreases, and this action of the inductor ensures stable discharge.

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: A wire-cut, electric-discharge machining power source which is provided with a first low-current discharge circuit and a second high-current discharge circuit. The first low-current discharge circuit makes a wire electrode positive and a workpiece negative, and the second high-current discharge circuit makes the wire electrode negative and the work positive. After triggering a discharge by the first low-current discharge circuit, a main discharge for machining is produced by the second high-current discharge circuit.

Abstract: A control system for stopping a spindle at a prescribed rotational position having a position control loop for driving a spindle so that a positional deviation between the present rotational position of a specified point on the spindle and a predetermined rotational position at which the specified point is to be stopped, is reduced to zero to stop the specified point on the spindle at the predetermined rotational position. Fine and coarse voltage signals are utilized for the final positioning process.