Nippon Kokan Kabushiki Kaisha

Nkk Corporation

Nippon Sanso Corporation

Yuji Sugitani

Hirokazu Nomura

Masatoshi Murayama

Yasuhiko Nishi

Naohiro Tamaoki

Yukio Kobayashi

Yasuo Suzuki

Yoshihiro Kanjo

Yoshikazu Sato

Daisuke Ozamoto

Kentaro Mori

Hirotaka Nakagawa

Akichika Ozeki

Takaho Kawawa

Tadashi Fujioka

Hideaki Mizukami

Takanori Nishimura

Naoyuki Gotoh

Yosihiro Kanjo

Hitoshi Serizawa

Yoshihisa Ikeda

Masatomo Murayama

Method of detecting root gap and arc welding method using the former

A lattice welding robot detects an X-axis slide position of X.sub.p by an arc sensor of a welding torch, compares the value of X.sub.p with a reference value of X.sub.0 by a comparator, calculates a differential value of the value of X.sub.p by a differentiator and computes a travel speed correction amount .DELTA.V from a difference between a comparator output value and a differentiator output value by a computing unit. The correction amount .DELTA.V is added to an initial speed of each of inside wheels and outside wheels of a welding carriage to control each of driving motors for the inside wheels and the outside wheels by an adding speed command V.sub.in and an adding speed command V.sub.out, respectively. Thereby, a rough guidance for the welding carriage to trace a weld line is performed.

Lattice welding robot and method for the lattice welding

A method for one-side root path welding of a pipe joint comprises the steps of forming a ring groove having a V-shaped bottom portion thereof at end faces of both pipes whose joint is circumferentially welded, attaching a backing material to a butt portion of the pipes from an internal side of the pipes, running an automatic welding machine along a guide rail mounted on an outer surface of the pipes in the circumferential direction thereof, controlling a position of a welding torch along a seam by means of an arc sensor, and welding root pass from the outer side of the pipes with a predetermined welding current and at a welding speed in a high-speed rotating arc welding of the pipes at a predetermined rotational speed and with a predetermined diameter of rotation. The rotational speed of arc is from 10 to 150 Hz. The rotation diameter of the arc is from 1 to 4 mm. The welding current is from 200 to 500 A. The welding speed is from 75 to 300 cm/min.

Method for one-side root pass welding of a pipe joint

An apparatus for detecting a shape of a groove, comprises: a device for forming picture images of a groove and a groove face of a work piece of metal to be welded with the use of a welding arc as illuminating light; a storage device for storing information on picture elements of the picture images formed by the device for forming picture images; an integrating device for integrating the information of the picture elements stored in the storage device in a predetermined direction of a memory in the storage device; a differentiating device for differentiating the integrated information in the direction rectangular to the predetermined direction of the memory; and a detecting device for detecting information of shapes of the groove and the groove face on the basis of the differentiated information on the picture elements. The apparatus for detecting a shape of a groove is provided with a processing device which processes command values of welding current and of a welding speed on the basis of information on shapes of the groove and the groove face. The device for forming an image is provided with an air nozzle open toward an image forming area.

Apparatus for detecting a shape of a groove

High-speed rotative arc welding device

Powder manufacturing apparatus and method therefor

A method for controlling a penetration bead, in an automatic one-side gas shielded arc welding wherein the backing material is adhered to the back of work pieces along a weld line and the welding is effected automatically from the surface side of the work pieces, comprises: putting an electrically conductive material on the surface of the backing material in the longitudinal direction; detecting a voltage between the work pieces and the electrically conductive material during the welding and controlling the voltage to be a predetermined reference voltage. The voltage is controlled by comparing the reference voltage and the detected voltage to obtain their difference and by correcting a speed of a travelling carriage which corresponds to the difference voltage to let the detected voltage be equal to the reference voltage. The electrically conductive material is one selected from a metallic foil tape, a metallic net and a wire.

Method for controlling a penetration bead

An apparatus for automatically welding a cylindrical vessel, which comprises: a rotating means (8) for rotating a cylindrical vessel to be welded around the center axis thereof; a travelling carriage (1); a manipulator (2) mounted on the carriage (1), said manipulator comprising a vertical post (10) secured onto the carriage (1), a horizontal column (11) movable horizontally and vertically along the vertical post (10), and an expansion arm (12) fitted rotatably to the leading end of the horizontal column (11); a welding head (4) fitted through an L-shaped fitting member (3) to the tip of the arm (12), said welding head comprising a welding nozzle (16), a groove profiling means (17) and a groove shooting means (20); a welding wire feeder (5) mounted on the carriage (1); a welding electric power source (6) mounted on the carriage (1); and a welding controller (9) mounted on the carriage (1), said welding controller comprising an image processor (32), a welding current controller (33), a welding wire feed controller (34), a welding speed controller (35), and a groove profiling controller (36).

Apparatus for automatically welding cylindrical vessel

There is disclosed a method for arc welding wherein an electrode wire is rotated to produce an arc rotating at an elevated speed and wherein the arc produced in this manner is used as an arc sensor for making a bevel profiling. According to the invention, the rotational speed of the arc N is set so as to be larger than a constant speed as determined by the time constant of the change of the wire melting speed so that the difference between the welding current when the electrode wire is at the center of the bevel and that when the electrode wire is at the extreme lateral position is increased to improve the bevel profing performance.

Bevel profiling control method for arc welding

A method for controlling a bead, in one-side automatic welding wherein a backing metal strip is adhered to the back side of a pair of work pieces through an inorganic material and arc welding is applied to the work pieces on the surface side thereof, comprises:detecting an electrical signal between the work pieces and the backing metal strip to control a weld current so that the detected electrical signal can be equal to a predetermined reference signal; and detecting the controlled weld electrical current and putting the detected weld electrical current into a formula of V.sub.1 =V.sub.0 .multidot.I.sub.L /I.sub.L0 to calculate a welding speed; and controlling the welding speed in accordance with the calculated welding speed, where V.sub.1 represents the calculated welding speed, V.sub.0 an initial value of the welding speed, I.sub.L the detected weld electrical current and I.sub.L0 a predetermined reference weld current. The electrical signal can be an electrical current signal or a voltage signal.

Method for controlling a bead

An automatic arc-welding method, which comprises when welding two objects to be welded together by means of a welding wire along a groove formed between the objects to be welded, continuously detemrining by calculation a target welding current, with which a depth of penetration agrees with a target value thereof, on the basis of the root gap, the material of the welding wire and the like; continuously determining by calculation a target feeding rate of the welding wire, at which an extension length of the welding wire agrees with a target value thereof, on the basis of the welding current, the material of the welding wire and the like; continuously determining by calculation a target welding voltage, with which a length of the arc agrees with a target value thereof, on the basis of the welding current, the feeding rate of the welding wire, the material of the welding wire and the like; and automatically controlling the welding current, the feeding rate of the welding wire and the welding voltage on the basis of the respective target values thus determined.

Automatic arc-welding method

An automatic arc-welding method, which comprises, when welding two objects to be welded together by means of a welding wire along a first groove formed between the objects to be welded on a first side thereof, continuously determining by calculation a target welding current, with which a depth of penetration agrees with a target value thereof, on the basis of the root gap, the material of the welding wire and the like; continuously determining by calculation a target feeding rate of the welding wire, at which an extension length of the welding wire agrees with a target value thereof, on the basis of the welding current, the material of the welding wire and the like; continuously determining by calculation a target welding speed, at which a height of the weld bead agrees with a target value thereof, on the basis of the feeding rate of the welding wire, the material of the welding wire, the root gap and the like; and on the other hand, when welding the objects to be welded together by means of the welding wire along a second groove formed on a second side of the objects to be welded, opposite to the first groove, continuously determining by calculation a target welding current and a target welding speed while taking into consideration the depth of penetration and the weld bead in the first groove; thereby automatically controlling the welding current, the feeding rate of the welding wire and the welding speed on the basis of the respective target values thus determined.

An automatic arc-welding method, which comprises, when welding two objects to be welded together by means of a welding wire along a groove formed between the objects to be welded, continuously determining by calculation a target welding current, with which a depth of penetration agrees with a target value thereof, on the basis of the root gap, the material of the welding wire and the like; continuously determining by calculation a target feeding rate of the welding wire, at which an extension length of the welding wire agrees with a target value thereof, on the basis of the welding current, the material of the welding wire and the like; and continuously determining by calculation a target welding speed, at which a height of the weld bead agrees with a target value thereof, on the basis of the feeding rate of the welding wire, the material of the welding wire, the root gap and the like; thereby automatically controlling the welding current, the feeding rate of the welding wire and the welding speed on the basis of the respective target values thus determined.

An automatic fillet welding method for effecting the welding by rotating a welding electrode and thereby rotating an arc at a high speed. By rotating the arc with a predetermined rotation direction, rotation speed and rotation diameter, a weld metal is prevented from running downward thereby forming a bead having uniform leg lengths and an excellent depth of penetration.

Method of high-speed rotation arc automatic fillet welding

A groove tracing control method for a fillet welding effected by rotating a welding torch and thereby rotating an arc at a high speed. The groove tracing control of the welding torch is effected in accordance with variations in the voltage waveform of the rotating arc and in this way the groove tracing is effected in real time in a noncontact manner with a high degree of accuracy.

Growing community of inventors

Tsu, Japan

Yuji Sugitani