Method of control of arc welding process
(57) Abstract:Method of control of arc welding process, which determines the calculated values of the electric parameters of the welding process and geometrical parameters of the weld pool, compare them with the current values, which are continuously measured during welding and, depending on their deviations produce the regulation of the welding process, wherein the pre-produce the welding samples of different lengths of the same material and the same thickness, and joint connection of the product, determine the maximum change in deflection width of the welding gap before welding arc from the set by changing the length of the welded sample while maintaining the quality of welding
B = max((Zi-Zi+1)(i-i+1)),
where is the maximum change in the magnitude of the welding gap, mm/m;
Zi- the maximum deviation of the welding gap, mm, from the given value, when welding sample lengthim;
Zi+1- the maximum deviation of the welding gap, mm, from the given value, when welding sample lengthi+1, m, then when welding butt joints products determine the score = (Zo- Zt)/t,
where Bt- the current deviation of the welding gap, mm/m;
Zo- the set value of the welding gap, mm;
Zt- the current value of the welding gap, mm;
t- the current length of the weld, m,
and if Btmore change In the calculated value of the welding current
IRK= Ip- k(Bt-B),
where IRK- calculated reference value of the welding current with a correction for changes of the welding gap along the length of the weld;
Ip- calculated reference value of welding current.
k is an empirical coefficient equal to 4.8.
FIELD: electric arc welding processes and equipment, possibly manual electric arc welding by means of coated electrode that may be in different spatial positions.
SUBSTANCE: welding is realized by means of modulated electric current at separate regulation of pulse and pause duration of welding electric current. During pause additional pulses with amplitude equal to that of main pulses, frequency no less than 50 Hz, duration (0.5 - 2) ms are applied on small welding current 5 - 30 A. Heat power of welding current is automatically realized according to action of welding operator due to changing parameters of main pulses depending upon fluctuation of mean voltage of electric arc from predetermined value at relatively small change of arc gap (2 - 2.5)V.
EFFECT: lowered contrast degree of irradiation of electric arc during pulse and pause, enhanced quality of welded joint, possibility for controlling heat power of electric arc according to desire of welding operator, improved topography of welded seam.
5 cl, 5 dwg, 5 ex
FIELD: electric welding processes and equipment, namely regulated power source for manual electric arc welding, possibly in workshops, in domestic or industrial condition.
SUBSTANCE: inlet of bridge type diode rectifier is connected with one section of secondary winding of transformer. Two gangs of capacitors are connected in parallel with diodes of one arm of bridge type rectifier and with one outlet of said section. Smoothing choke with split windings is connected between arms of bridge type rectifier. Secondary winding of transformer includes additional booster section to which two thyristors are connected. Said thyristors are controlled by means of pulse-phase control system. The last includes double-threshold comparator whose inlet is connected with outlet of power source and whose outlet is connected with inlet for interlocking pulses of pulse-phase control system.
EFFECT: possibility for proving smooth regulation of welding electric current in desired range.
FIELD: welding processes and equipment, namely method for controlling manufacturing equipment providing pulse feed of welding wire to electric arc zone.
SUBSTANCE: method comprises steps of applying signal to adaptive system for controlling mechanism for pulse feed of welding wire. During automatic mode in said system control signal source is operated. Source of control signal is in the form of pickup for measuring welding wire force in guiding duct of welding hose and feed stroke pickup. Pulse is generated at time moment when welding wire achieves in guiding duct energy corresponding to optimal acceleration of welding wire motion. Pulse repetition frequency is set by adjustment of force pickup, by speed of feed mechanism and by stroke set by welding wire feed stroke pickup.
EFFECT: simplified control circuit, regulation of stroke of welding wire feed and therefore of size of drops of electrode metal transferred to welding bath.
FIELD: mechanical engineering; welding.
SUBSTANCE: invention relates to two-stage electric arc welding sets and methods of their operation. Proposed set includes quick-acting impulse supply source 10 with controller 130 for implementing first and second welding processes in space between part to be welded W and welding wire E moved in direction towards part W. During first stage first current signal waveform is used, and during second stage, second current signal waveform. Circuit is provided to change over first and second welding processes. Change-over circuit includes counter 212 to count signals during first and second processes, and circuit 190 to change over from one welding process to other welding process at moment when counted signals in carried out welding process reach preset value for this process. Invention provides quality gas-shielded welding by consumable electrode with changing over of welding process with transfer of metal owing to surface tension, or process of welding at constant stress with jet transfer to other process of welding.
EFFECT: enlarged operating capabilities.
87 cl, 4 dwg
FIELD: welding manufacturing processes, namely system for inspecting state of welding zone, possibly used in all branches of machine engineering.
SUBSTANCE: welding control system includes welding apparatus and apparatus for monitoring welding zone state. The last is provided with device for displaying image of welding zone, at least one filter arranged in front of display device or inside it, device for illuminating welding zone by means of UV irradiation. Said filter is band type filter for passing irradiation in vicinity of predetermined wavelength of UV irradiation.
EFFECT: enhanced reliability of welding process.
34 cl, 6 dwg
FIELD: welding jobs.
SUBSTANCE: invention relates to welding, particularly to the method of welding metal products and to welding apparatus. The welding apparatus incorporates the short-arc welding system and allows the electrode to move towards the structure to be welded and to adjust the arc length. The welded seam produced by the short-arc welding meets the requirements of API 5L for pipe welding of at least X80 class, the arc length in welding not exceeding 0.3 inch. The system additionally comprises a power source with a regulator to create current pulse to feed power to electrode to fuse the self-protected electrode and a section of smooth metal transfer with low current that follows behind the end of fusing pulse during which fused electrode gets connected with the structure being welded.
EFFECT: welding pipelines together.
43 cl, 18 dwg, 3 tbl
FIELD: welding jobs.
SUBSTANCE: invention covers the method and device of machine arc welding in active gases that features intermittent alternation of the stages and arc discharge and short-circuiting, and can be used for producing seams in whatever spatial positions, for example, in welding the pipelines joints. At the stage of arc discharge bath damping is provided for by stabilising the voltage in two automatic control cycles. The first of them stabilises the voltage of arc proper, while the second stabilises the medium welding voltage. At the short-circuit stage bath damping is provided for by reducing electro dynamic effects onto the bath via reduction in sizes of transferred drops, which is reached thanks to bringing the frequency of pulsed effects into agreement with the natural frequency of drop formation by generating the current fall that initiates the transfer process, and the subsequent short-circuit current peak that allows the drop to detach from the electrode. The device primary power circuit outputs and high-voltage backfeed circuits are integrated and connected, via the current pickup, to external terminals. The current pickup output is connected to the microprocessor controller first measuring input. The voltage pickup output is connected to the microprocessor controller first measuring output. The first control output of microprocessor controller is connected to the controlled input of thyristor rectifier unit. The second control output of microprocessor controller is connected to the control input of the fist magnetic starter. The output of the operating conditions control unit is connected to the data input of microprocessor controller. The device low-voltage backfeed circuit is made up of the following components connected in series, i.e. transformer third output, second magnetic starter, second diode rectifier and controlled throttle. The output of low-voltage backfeed circuit is connected to the current pickup input. The fourth control input of microprocessor controller is connected to the controlled input of the second magnetic starter. The third control output of microprocessor controller is connected with the controlled input of controlled throttle. The output of the external feedback communication voltage pickup is connected to the third measuring input.
EFFECT: control of fused metal bath to produce high-quality welded seam.
6 cl, 6 dwg
SUBSTANCE: invention relates to a method and device for consumable-electrode arc welding and can be used in manual or machine welding of joints of main and industrial pipelines, as well as other metal structures in different industries. When welding, transfer of electrode metal is controlled during the short circuit period. Before the short circuit, welding current is bridged and reduced to zero. Then during the short circuit period, welding current is varied proportionally to electrical conductivity of the liquid metal jumper. At the end of the short circuit, welding current is once again reduced to zero. After the short circuit, bridging is stopped and arcing is induced at the peak level of welding current, which during arcing, is gradually reduced to a base level. The device has a direct current power supply, throttle, current sensor, control unit, electrode, stabilitron, delay line and N diodes, connected in series and accordingly. The throttle has an impregnable magnetic core and a split winding.
EFFECT: prevention of metal sputtering during the short circuit period.
3 cl, 3 dwg
SUBSTANCE: tandem welding system comprises spaced apart electrodes for movement with same speed and jointly making weld joints. A data storage device stores measured data for each electrode when making a weld joint. The device carries out a process, which includes selection of measured data for each electrode, corresponding to the electrode passing through a control position and comparison of selected measured data of several spaced out electrodes for calculation of the weld joint parametre of the tandem welding system in the control position.
EFFECT: increased operational reliability.
38 cl, 8 dwg
FIELD: electrical engineering, welding.
SUBSTANCE: arc is fed by pulsed welding current with parametres that allow arcing in dynamic mode. Arc, in above conditions, features high physical stability given a concentrated heat feed into welded product. Proposed method provided for control over heat feed by smoothly varying pulse repetition frequency and preset current pulse amplitude through variation of power supply voltage and stepwise variation of pulse duration in inverse proportion to departure of mean voltage at arc from preset voltage.
EFFECT: through penetration, formation of keyhole-type pilot hole and root pass in various positions of weld pool.
3 dwg, 1 ex