Daihen Corporation

Akihiro Ide

Tetsuo Era

Futoshi Nishisaka

Hiroyasu Mondori

Toshiyuki Tanaka

An arc welder includes a welding power supply, a forward/reverse welding wire feeder, and a controller for the power supply and the wire feeder. Welding is implemented by repeating unit welding steps each including a short circuit stage with the welding wire and a base material being short-circuited and an arc stage with an arc being generated between the wire and the material. A transition period continues from a starting point of the arc stage till the wire feeding rate reaches a forward maximum. An average welding current is defined as an average of the welding current during the short circuit and arc stages. Within the transition period, the controller sets a current suppression period during which welding current is smaller than the average welding current. Transition period length Tand current suppression period length Tare set to satisfy the inequality 0&#x3c;T/T&#x2264;0.8.

Arc welding apparatus and arc welding method

There is provided an arc welding control method of performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly at a time of staring the welding. The forward/reverse feeding control is started from the reverse feeding period of the welding wire after starting conduction of a welding current.

Arc welding control method

There is provided an arc welding control method of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, controlling a welding voltage based on a voltage setting value and alternating short-circuiting periods and arc periods to perform welding. In the arc welding control method a cycle of the feeding rate is changed based on the voltage setting value.

There is provided an arc welding control method of feeding a welding wire according to a push-pull feeding control using a push-side feeding motor which rotates in a forward feeding direction at a feeding rate set to a push feeding-rate setting value and a pull-side feeding motor which alternates a forward feeding rotation and a reverse feeding rotation periodically, and generating short-circuiting periods and arc periods to perform welding. An average feeding rate of the pull-side feeding motor is detected. The push feeding-rate setting value is corrected to the detected average feeding rate of the pull-side feeding motor.

The present invention improves the stability of welding conditions in a welding method that involves cyclically repeating forward feed and reverse feed of a welding wire. Provided is an arc welding control method involving cyclic repetition of forward feed and reverse feed of a welding wire at feed speed, generating short-circuit intervals and arc intervals, during which arc intervals, application of a first welding current is followed by application of a second welding current smaller than the first welding current, wherein the phase of the feed speed at the point in time of transition from an arc interval to a short-circuit interval is detected, and the value and/or the application duration of the first welding current is varied in accordance with the detected phase. In so doing, fluctuation of the phase of the feed speed due to outside disturbances during generation of short-circuiting can be minimized.

There is provided an arc welding control method of alternating feeding of a welding wire between forward feeding and reverse feeding periodically according to a feeding rate pattern constituted of a forward feeding amplitude, a reverse feeding amplitude, a forward feeding period and a reverse feeding period, stored in correspondence to an average feeding rate setting value, and generating short-circuiting periods and arc periods to perform welding. An average feeding rate of the welding wire is detected, and at least one of the forward feeding amplitude, the reverse feeding amplitude, the forward feeding period or the reverse feeding period is changed so that the detected average feeding rate equals the average feeding rate setting value, thereby automatically correcting the feeding rate pattern.

There is provided an arc welding power supply. An output control unit outputs welding voltage and current in correspondence to each of a short-circuiting period and an arc period. A feeding control unit controls a feeding rate of a welding wire. A short-circuit forcibly generating period is provided between forward feeding acceleration and deceleration periods. In the short-circuit forcibly generating period, the feeding control unit increases the feeding rate with a change rate larger than a change rate during the forward feeding acceleration period and maintains a predetermined forward feeding peak value when the feeding rate reaches the peak value.

Arc-welding power supply

The present invention improves the stability of arc welding carried out by cyclical repetition of forward feed and reverse feed of a weld wire. An arc welding control method includes repeated forward feed and reverse feed at a weld wire feed rate, according to a prescribed cycle and a prescribed amplitude, and generation of short-circuit time intervals and arc time intervals to carry out welding, wherein the feed rate cycle and/or the amplitude are set automatically on the basis of the average feed rate and the welding rate, or the wire deposition amount per unit of weld length. Further, in the event that the amplitude has changed, feedback control of the forward feed-side shift amount is carried out in such a way that the average value of the feed rate is constant. In so doing, the feed rate cycle and amplitude are always set to optimal values.

A method is provided for controlling a neck detection for a welding power supply. The neck detection can be suitably performed even if the welding power supply is combined with another power supply for performing a simultaneous arc welding operation at a plurality of locations of a workpiece. The method includes using a control target welding power supply together with another power supply for performing arc welding concurrently at a plurality of locations of a common workpiece, detecting a neck in a molten portion of a welding wire which is brought into short-circuiting contact with the common workpiece, reducing the welding current for forming an arc, and automatically adjusting a neck detection value.

Method for controlling neck detection for welding power supply

There is provided an arc welding control method of alternating feeding of a welding wire between forward feeding and reverse feeding periodically to generate a short-circuiting period and an arc period in a manner that shifting to the arc period is performed by reducing a welding current in the reverse feeding during the short-circuiting period. Reduction of the welding current is started from a time where a state of the reverse feeding reaches a predetermined reference state.

A welding device includes a power supply circuit for applying a voltage across a torch and a base metal, and a power supply control device. The power supply control device controls the power supply circuit such that a high level current is output during a first arc period Tathat is the initial period of an arc period, and an arc current corresponding to a regulated welding voltage is output during a second arc period Tathat is the latter period of the arc period. The power supply control device controls the power supply circuit such that a high level current is generated having a waveform increasing and decreasing at a constant frequency and constant amplitude superimposed on the high level current. By superimposing the waveform, the elevation of a droplet caused by an repelled force by the arc can be prevented, allowing a droplet to be formed in stabilization.

Welding device and carbon dioxide gas shielded arc welding method

A feed control method is provided for consumable electrode AC arc welding, in which the welding wire is fed at a predetermined wire feed rate, and a welding voltage applied to an arc is switched in alternation between positive polarity and negative polarity. In the method, a welding current setting signal is generated. The wire is fed at a first feed rate during a period of the positive polarity, whereas the wire is fed at a second feed rate different from the first feed rate during a period of the negative polarity.

Feed control method for consumable electrode AC arc welding

An arc welding power source supplies a start current, a welding current and a crater current as an output current in accordance with an activating signal supplied from outside. The power source includes a start period setting unit, a crater period setting unit, and a current control unit that controls the output current. The current control unit causes the power source to supply the start current and the welding current consecutively while the activating signal is in an on-state, where the start current is supplied for the start period, and the welding current is supplied for the period following the start period. The current control unit also causes the power source to supply the crater current after the activating signal is turned off, where the crater current is supplied for the crater period.

Arc welding power source

A squeezing detection control method is provided for consumable electrode arc welding. The method includes a step of detecting a droplet squeezing phenomenon by checking that a change in a voltage or resistance between the consumable electrode and base material reaches a squeezing detection reference value, and a step of executing output control for rapidly decreasing a welding current passing through a short-circuited load when the squeezing phenomenon is detected, so that arc re-striking occurs in a state of low current. The squeezing detection reference value is set to a first value during the electrode positive polarity, and set to a second value during the electrode negative polarity. The second value is different from the absolute value of the first value, and each of the first and second values is set such that the resultant welding state is satisfactory.

Squeezing detection control method for consumable electrode arc welding

A welding current controlling method is provided for an arc welding process using a consumable electrode and including an alternate repetition of a short-circuiting state and an arc generating state occurring between the consumable electrode and a base material. In the method, a neck detection is performed for the molten electrode in the short-circuiting period of time to determine if a new arc is established between the consumable electrode and the base material. Upon detection of the neck, the welding current is sharply decreased. After the new arc is established, the welding current is increased from a low level to a high level with a predetermined inclination selected for reducing vibration to the molten pool.

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Osaka, Japan

Akihiro Ide