Abstract: An articulated industrial robot has an articulated horizontal arm assembly which includes horizontal arms (20), a vertically movable shaft (20) mounted on the extremity of the horizontal arm assembly, and a motor for driving the vertically movable shaft. When directly teaching motions to the vertically movable shaft through a direct teaching operation by an operator, the current control unit of a motor control unit for driving the motor for driving the vertically movable shaft is disconnected from a signal line connected to a robot control unit, and a torque calculating circuit is provided for deciding a motor torque corresponding to the sum of the weight of the vertically movable shaft and the respective variable weights of an end effector attached to the lower end of the vertically movable shaft.

Abstract: A motor drive method is provided which is capable of preventing suspension of operation of an industrial robot, and preventing deviation of the track of movement from a command track, attributable to an overload state of a motor. Output torque command values for motors for various axes of the robot are detected (S1). When any one of the detected values exceeds a predetermined value, which is determined in accordance with the maximum output torque of each corresponding one of the motors for the various axes, an amount of move command per unit time, for every one of the axes, is reduced. The amount of move command per unit time is reduced by using the torque command values thus increased, the product of an override value and a coefficient obtained in accordance with the differential of the torque command values (S3, S6 and S14), whereby the overload state of the motor is prevented.

Abstract: The wrist assembly of an industrial robot comprises a first wrist portion (21) provided on the free end of the robot arm (20) and having a pair of projections (22, 23) in parallel with each other on the fore-end thereof. A second wrist portion (24) is provided between the projections of the first wrist portion and supported on both of the projections so as to be rotatable about a first axis (.beta.) intersecting a longitudinal axis of the robot arm at a right angle. A third wrist portion (25) is supported on the second wrist portion so as to be rotatable about a second axis (.alpha.) intersecting the first axis at a right angle, and constructed to allow work attachments to be attached to the front end thereof. A first motor (45) and a second motor (55) are used for driving the second wrist portion and the third wrist portion.

Abstract: In an industrial robot employing electric motors (Mz, M.theta., Mu, Mw) as drive sources for driving functional robot units for movement respectively about articulatory axes (Z, .theta., U, W), electric drive currents supplied to the electric motors (Mz, M.theta., Mu, Mw) associated with the articulatory axes (Z, .theta., U, W) are detected by a current detecting unit (30), the detected electric drive current supplied to the electric motor (Mz, M.theta., Mu, Mw) associated with one selected articulatory axis among the articulatory axes (Z, .theta., U, W) is sampled every predetermined minute sampling time in a period between a first time and a second time in a robot control program for controlling the motions of the functional robot units respectively about the articulatory axes (Z, .theta., W), computing means (CPU) calculates the ratio of the root-mean-square value of the electric current supplied to the electric motor (Mz, M.theta.

Abstract: An industrial robot (10) comprising a cylindrical fixed robot body (14), a swivel body (26) mounted on the fixed robot body (14), a robot arm mechanism (60, 64) pivotally joined to the swivel body (26), and a robot wrist (66) connected to the robot arm mechanism is provided with a cable guide member (30). The cable guide member (30) is extended along the outside of the fixed robot body (14) and has a lower end pivotally joined to the fixed robot body (14) by a lower bearing member (42) and an upper end pivotally joined to the swivel body (26) by an upper bearing member (40). The cables (50) of the industrial robot (10) extending from the lower end of the fixed robot body (14) are held by cable holding section (32) formed in the middle portion of the cable guide member (30) and are extended from the upper end of the cable holding member (30) through the swivel body (26) toward the robot arm mechanism.

Abstract: An industrial robot rotation shaft apparatus according to the invention has a waterproof structure obtained by providing the outer surface of a rotatable support (3) with an integrally formed, peripheral skirt portion (3c). A stationary support (2) is provided with a complementary, projecting collar portion (7b) substantially conforming to the inner surface of the skirt portion. The two complementary elements oppose each other while maintaining a small clearance therebetween. This makes it possible to shut out dust, water droplets and the like which would otherwise penetrate the interior of the robot from outside. As a result, rusting of the internal parts and the motor due to water droplets and debris penetrating the same is prevented.

Abstract: Angular regions (A, B) for turning a trunk body (12) of an industrial robot can be changed in accordance with an operation of the industrial robot by setting movable stoppers (18, 20). Turning movement can be stopped by an electrical means (LS1, LS2, LS3, LS4, LS5) to protect a drive motor and a drive mechanism, just before a stopper (22) fixed on the trunk body collides with mechanical stoppers (14, 16, 18, 20). An accident based on an error operation of the movable stoppers can be prevented by disposing proximity detectors (PS1, PS2, PS3, PS4).

Abstract: An industrial robot for use in TIG arc welding or the like includes plastic covers for motors or the like. The plastic covers having an electrically conductive coating, and thus have an electrically conductive property, and are connected to a robot body, to thereby obtain a shielding effect similar to that of iron plate covers or the like.

Abstract: An automatic welding apparatus carrying out an arc sensing operation is provided with a memory (2) storing parameters for arc sensing, and these parameters being rewritten by a manual input before beginning the welding, by an input from an on-line computer during the welding, or at a predetermined time by a program which outputs commands to the automatic welding apparatus (FIG. 6).

Abstract: A system for controlling acceleration and deceleration of a horizontally articulated robot computes the distance from the center of rotation of the robot (A) having a plurality of arms (3, 5) angularly movable in horizontal planes to a reference position such as a wrist (51) at the distal end of the arms (3, 5), and establishes an acceleration for the movement of the distal end of the arms (3, 5). A servomotor for angularly moving the arms (3,5) can effectively be utilized and the arms (3, 5) can quickly and smoothly be moved.

Abstract: A method of starting arc sensing applicable to automatic welding apparatuses carrying out an arc sensing operation, which is a control operation comprising: detecting deviations of a welding electrode from a predetermined path in an up or down direction and right or left direction, by variations of a welding current while welding with a weaving operation; and correcting the deviation.In this method of starting arc sensing, the welding electrode is held in the dwell state while the arc is extremely unstable just after the arc is first generated, a weaving is carried out from a first predetermined time (T.sub.1) after the extreme instability of the arc has been eliminated, a detection and correction by an arc sensing of a deviation in the right and left direction only are carried out from a second predetermined time (T.sub.

Abstract: A cable arranging device for an industrial robot has a cylindrical support casing (2), a swing casing (3) supported on the support casing (2) and swingable about the axis of a swing shaft, and cables (5) interconnecting the swing casing (3) and the support casing (2). One end of a substantially C-shaped cable guide (4) is pivotally supported in the swing casing on the axis of the swing shaft, the other end of the cable guide is pivotally supported in the support casing on the axis of the swing shaft. Spaces for allowing the cable guide (4) to swing therein through a prescribed angle are defined respectively in the swing casing (3) and the support casing (2).

Abstract: A direct-drive-type multi-articulated robot comprising: a stationary support shaft (14), a cylindrical rotary casing (16) surrounding the stationary support shaft (14), a first robot arm (18) joined to the upper end (16a) of the rotary casing (16), a second robot arm (20) pivotally joined to the extremity of the first robot arm (18), a direct-drive motor (M.theta.) interposed between the lower end of the rotary casing (16) and the lower end of the stationary support shaft (14) to drive the rotary casing (16) and the first robot arm (18) together for turning motion, a brake gear (24) interposed between the upper end (14a) of the stationary support shaft (14) and the first robot arm (18) to arrest the turning motion of the first robot arm (18), and an encoder (26) for detecting turning motion, interposed between the upper end (14a) of the stationary support shaft (14) and the first robot arm (18).

Abstract: A system for controlling a robot includes a control portion (7) for supplying a control signal to and receiving a control signal from a servo unit (6) for carrying out a signal supply and a signal feedback to an electric motor (5) for driving a shaft executing a Z-axis linear motion, and threshold value supply portion (8) for supplying a threshold value to the control portion. Based on a comparison between a motor torque instruction value and a threshold value supplied from the threshold value supplying portion, an alarm is delivered and the process subsequently proceeds to a step of dealing with an abnormal condition when said motor torque instruction value becomes greater than a predetermined threshold value.

Abstract: An apparatus for guiding a cable of an industrial robot having a support casing and a swivel casing axially supported by a swivel shaft bearing includes a cable guide. The guide has an end of an upper arm axially supported on a swivel axis inside the swivel casing, and an end of a lower arm axially supported on the swivel axis inside the support casing. A back column formed between the upper and lower arms guide passes through first and second arcuate cut-out portions provided in the swivel casing and support casing. A cable is passed from the support casing into the swivel casing along the cable guide back column, and moves proportionately to angular movement of the swivel casing.

Abstract: An arm structure for an industrial robot, comprising a first robot arm (16) supported on top of a vertical robot shaft (14), and a second robot arm (20) pivotally joined through a transmission-reduction gear box (18) to the free end of the first robot arm (16). A plurality of coupling bolts (22) are extended through the interior of the first robot arm (16), each coupling bolt (22) has one end (22b) fastened to the flange (18b) of the transmission-reduction gear box (18) and the other end (22a) projecting from and fastened to the rear end of the first robot arm (16). Fastening nuts (24) each engage at least one end (22a or 22b) of each coupling bolt (22) to couple the first robot arm (16) and the transmission-reduction gear box (18) so as to preload the first robot arm (16) by a compressive force.

Abstract: The arc current is divided into two areas each corresponding to a 1/4 period of weaving, the two areas are compared with each other, and an area corresponding to a predetermined time period at the end portion of the larger area is substrated from the larger area and another area comparison is performed. The movement of the welding torch is compensated in accordance with the predetermined correction function, so that, even when an actual weld line of base metals to be welded deviates from an instructed weld line, the welding torch is correctly moved along the weld line of the base materials and arc welding is performed.

Abstract: A vertical milti-articulated robot comprises a base (11) secured to a plane (10) of installation. The base (11) is provided with a turning body (12) which is rotatable relative to a reference position of the base about a first axis (.theta.) perpendicular to the plane of installation within an angular range of nearly 90 degrees to the right and to the left, respectively. The turning body (12) is rotated by a body drive motor (14) about the first axis. An upper arm (16) having a base end and a tip is coupled at the base end thereof to the turning body (12) so as to be rotatable relative to the turning body about a second horizontal axis (W) from a nearly vertical attitude toward the front of the turning body. A forearm (19) having at the front end thereof a wrist assembly (20) is coupled to the tip of the upper arm so as to be rotatable relative to the upper arm about a third axis (U) which is parallel to the second axis.

Abstract: An industrial robot having a dust-proof structure is equipped with at least one dust cover having an opening at one end thereof and a linearly movable unit extending through the opening of the dust cover and movable back and forth in the longitudinal direction thereof. Suction is exerted by a suction unit inside the dust cover so that air is flows from outside the dust cover into the same through the opening. A ring member is disposed at the opening of the dust cover in such a manner as to encompass the outer periphery of the linearly moving unit through a gap. At least one annular groove for reserving air is disposed on the inner peripheral surface of the ring member so as to encompass the outer periphery of the linearly moving unit.

Abstract: A system for converting the welding conditions of a welding robot includes a numerical control unit, which is for controlling the welding robot (8) and a welding machine (7). A memory (3) is included for storing a calculation sequence of a general expression of a given straight line obtained from an X value of a point (U=0) on the given straight line and the slope of the given straight line on a plane in which a welding condition input value is plotted along the X axis and a command value delivered to a digital/analog converter that applies commands to the welding machine is plotted along the Y axis. A value is obtained by substituting a welding condition input value, which is applied when the welding robot is taught, into the general expression stored in the memory (3), the value obtained being adapted as an output value supplied to the digital/analog converter.