CN100528447C - Method of double filum narrow interstice alternating-direct current pulse matching electric arc welding - Google Patents

Abstract

The present invention relates to a narrow gap welding method which belongs to the technique field of the welding technology. A double-thread narrow gap alternating-direct current pulse matching electric arc welding method comprises the following procedures: connecting equipment and regulating the parameter of the alternating current welding machine; connecting the control end of the double-thread alternating-current/direct current welding controller with the scheduled end of the potentiometer of the direct-current welding machine; setting the base electric voltage of the direct current impulse and setting the spike voltage of the direct current impulse; setting the wire feeding rate of the two welding sticks and the range is between 1 and 15m/min; connecting the detecting end of the controller with the alternating current welding machine and the voltage signal is obtained; treating the voltage signal with the detecting module to detecting signal and inputting the control module; generating the direct current impulse controlling signal and outputting to the control end by the calculating of the control module; regulating the controller mode to cause that the controller runs at the impulse outputting mode and outputting the impulse signal required by the designing; and doing welding. The invention guarantees the lateral wall fusing and increases the reliability of the welding equipment and facilitates the maintenance by the acting force between the two electrical arcs.

Description

The double filum narrow interstice alternating-direct current pulse matching electric arc welding method

Technical field

The present invention relates to a kind of narrow gap welding method, belong to the welding technique field.

Background technology

The narrow gap welding connection technology is a kind of high-quality, high production rate, the special industrial technology of low production cost, from technical standpoint, its many technological merit is determining this technology in all the slab scopes except that thin plate great temptation to be arranged all, from economic angle, there is the problem of an economic thickness of slab really in the narrow gap welding connection technology.In general, thickness of slab is big more, and its economic benefit is big more.

Narrow gap welding connects and mainly comprises two kinds; a kind of is gas metal-arc welding (GMAW); the method extensive use in industrially developed country (the technical literature ratio is up to about 70%); low heat input (20KJ/cm) during this method adopts easily; can adopt littler root gap, be easy to adopt the multilayer multiple tracks deposited and need not scarfing cinder etc.Next is the submerged-arc welding method, this method is responsive unlike the GMAW method to the active position of welding wire in groove, applicable craft standard broad, the reliability of technology excellence, the weld job environment more becomes " greenization ", but its weld heat input big (generally at 30-50kJ/cm), the moulding of joint, poor toughness, use this technology on the important structure and must carry out post weld heat treatment, cost is higher.Equally under the condition of narrow gap, two kinds of technology all are faced with same problem, be exactly that arc axis is parallel with groove face (to call sidewall in the following text), electric arc itself is difficult to have an effect with it, this just caused sidewall fusion the poor reliability GMAW of heat input (low very outstanding) this be the greatest difficulty that narrow gap welding connects, also be the key issue that this patent will solve.

" Narrow-Groove Mechanized Arc Welding-Advanced Welding Techniques " technology that Framatome is introduced on the energy project welding international symposium of holding in Shanghai in 2005 is by using rotary narrow clearance welding gun, in welding process, utilize mechanical mechanism to make welding wire carry out 360 ° of rotations in the upper end, molten bath, thereby solved the problem that sidewall merges, obtained the approval of conference, but owing to use this revolving welding gun to increase plant equipment, make whole welding system be tending towards complicated, could fully guarantee fusion penetration because its speed of welding will cooperate with rotary speed simultaneously, on the efficient of welding, perform poor.In addition, preside over the patented technology of the double strings narrow chink slugging arc welding process by name (patent number 85104150) of development by Harbin institute of welding Lin Shangyang academician, also be on the shape of welding gun and function, to make an issue of, the design of its double-wire welding gun is very much ingenious, the oblique toward side wall of tip of silk before it, the back silk makes two to form the antarafacial structure in the space then vertically downward, has obtained social approval equally.These two kinds of technology have just been improved contacting of welding gun electric arc and sidewall by the method for machinery, do not see the effect of active force in solution sidewall fusion problem of electric arc self.

Summary of the invention

This patent proposes a kind of double filum narrow interstice alternating-direct current pulse matching electric arc welding method by the direct current welding is combined with exchanging welding.

Active force by double-wire alternating current-direct current welding controller control alternating current arc and direct-current arc, concrete control thought is just to make direct current welding wire termination, workpiece connects negative simultaneously, when the interchange end of welding is positive voltage, the control DC welder produces the pulse base value, and the electric arc gravitation minimum that such two electric arcs produce is when alternating current arc is in negative voltage, the control DC welder produces peak value of pulse, the electric arc repulsion maximum that such two electric arcs produce, promptly by control two welding wire current impulses, control welding arc power, make repulsion maximization between the electric arc, gravitation minimizes, and when two electric arcs are in repulsion during the stage, repulsion is exaggerated as much as possible, so two electric arcs extremely are partial to sidewall, so just guaranteed the fusion of sidewall, when electric arc is in the gravitation, because gravitation is reduced as far as possible, make electric arc keep certain deflection, guaranteed fusion penetration.

A kind of double filum narrow interstice alternating-direct current pulse matching electric arc welding method comprises the steps:

Step 1: connection device, regulate the A.C. welder parameter, frequency is power frequency 50Hz, alternating voltage virtual value span 35～90V;

Step 2: the control end of double-wire alternating current-direct current welding controller is connected with the potentiometer given side of dc welding machine;

Step 3: the base value voltage of given DC pulse, scope are 16～22V, the crest voltage of given DC pulse, and peak voltage ranges is 28～40V;

Step 4: two welding wire feeding speed are given, scope 1～15m/min;

Step 5: the test side of controller is connected with A.C. welder, obtains voltage signal;

Step 6: voltage signal resume module after testing is a detection signal, two-way low level signal input control module;

Step 7: calculate through control module, generate the DC pulse control signal and output to control end;

Step 8: the adjustment control pattern makes it to operate in pulsed output mode, the pulse signal of output designing requirement;

Step 9: welding, electric arc produces the maximum of repelling each other immediately, inhales minimum stress mutually, and electric arc is partial to sidewall to greatest extent and is solved sidewall fusion problem.

This patent has used dc welding machine, A.C. welder, and mariages AC-to-DC welding controller, this controller comprises two modules, the one, exchange detection module, and another is the DC pulse control module, the basic controlling thought of this controller is, by detecting the positive-negative half-cycle of alternating current, control the pulse signal of DC current, thereby control the arc force of two electric arcs, make the repulsion maximum of two electric arcs and the gravitation minimum, utilize repulsion between the electric arc to solve the problem of sidewall fusion.

The present invention has following advantage with respect to prior art:

(1) under the effect of alternating current arc and DC pulse electric arc, two electric arcs swing, and make the central area of electric arc can affact the sidewall of narrow gap weld seam, improve the fusion of sidewall, have just solved sidewall and have merged bad traditional problem.

Utilizing the active force of electric arc self when (2) native system does not add any plant equipment, solve sidewall and merge problem, is simplifying the structure of entire mechanism, highly versatile, the also corresponding raising of the reliability of equipment.

(3) configuration of the mariages of native system significantly promotes the welding efficiency of system, has satisfied now to the high efficiency requirement of welding.

(4) cyclically-varying of electric arc pulse, making the active force cyclically-varying of electric arc itself has tangible concussion effect to the molten bath in this effect, and this effect makes grain refinement, has improved the mechanical property of joint.

(5) this patent both can adopt the open arc welding method of gas shielded arc welding, can adopt the method for submerged-arc welding again, and applicability is extensive.This patent has adopted the mariages configuration, and efficient improves obviously, the most important thing is that this patent utilizes the active force between two electric arcs to guarantee sidewall fusion, and the reliability of welding equipment is improved, and is convenient to safeguard.

Description of drawings

Fig. 1 controller block diagram;

Fig. 2 voltage acquisition filter circuit;

Fig. 3 voltage zero-cross circuit;

Fig. 4 standard differential circuit;

Fig. 5 dividing potential drop is isolated and half-wave rectifying circuit;

Fig. 6 control end signal output waveform;

Fig. 7 amplifier LM324;

Fig. 8 phase inverter MC14584BCP;

AT89C2051's resets and the clock circuit in Fig. 9 controller;

Figure 10 shows decoder driver circuit;

Figure 11 charactron chip select decoder driver circuit;

Figure 12 keyboard interface circuit;

Figure 13 photoelectrical coupler schematic diagram; 1,3 represents ANODE among the figure; 2,4 represent CATHODE; 5,7 represent EMITTER; 6,8 represent COLLECTOR;

Figure 14 controller circuitry schematic diagram;

The voltage current waveform comparison diagram of first group of parameter of Figure 15;

The voltage current waveform comparison diagram of second group of parameter of Figure 16;

Figure 17 mariages AC-to-DC welding controller welding process schematic diagram;

The specific embodiment

In test of the present invention, the capital equipment of employing is: one of dc welding machine, and one of A.C. welder, two of wire-feed motor, mariages is handed over--and one of direct current welding controller, welding wire is some.

This controller has adopted modularized design, divide two modules, promptly exchange detection module, to call detection module in the following text, the dc welding machine pulse control module, to call control module in the following text, detection module has adopted the method for designing based on analog circuit, it is the numeric structure of core that control module has adopted with the MCU single-chip microcomputer, have 3 mode of operations, can make the source of welding current with constant peak voltage pattern (mode1), constant base value voltage mode (mode2), peak value-base value pulse voltage pattern (mode3) output respectively, can in practical operation, select for use flexibly.Entire controller has adopted " black box " pattern, and interface is succinct, and the productionization extent of equipment is higher.The block diagram of controller, as shown in Figure 1.

Detection module

(1) voltage acquisition filter circuit

Filter circuit adopted have that passive original paper R, C and integrated operational amplifier constitute by former filter circuit, the a-c cycle scope that this controller detects is at 10～200Hz, the serious the design of voltage pulsation who considers alternating current arc adopts low-pass filter circuit, be limited to 500Hz in the design, the high non-load voltage of A.C. welder is approximately about 100v, need carry out dividing potential drop and filtering earlier so gather the voltage of coming in, in order to strengthen filter effect, this circuit has adopted two-stage filtering, one-level active power filtering and one-level active power filtering, the voltage acquisition filter circuit as shown in Figure 2.

(2) voltage zero-cross comparison circuit and differential circuit

To collect the voltage zero-crossing signal of alternating current arc in this problem, so adopt the voltage zero-cross comparison circuit.Differential circuit can be converted to the spike ripple to square wave, and the output waveform of differential circuit only reflects the sudden change part of importing waveform, and just there is output the moment of promptly having only the input waveform to undergo mutation.

By the voltage that the voltage acquisition filter circuit is come in, deliver to the voltage zero-cross comparison circuit, carry out the zero passage comparison operation through operational amplifier, pass through differential circuit again, be output as the positive pulse signal of positive half-wave zero passage moment and the undersuing of negative half-wave zero passage moment.The circuit of voltage zero-cross comparison circuit as shown in Figure 3.Typical differential circuit has shown in Figure 4.

(3) dividing potential drop is isolated and half-wave rectifying circuit

Because the voltage of front stage circuits output has exceeded the input voltage of single-chip microcomputer, thus at first should carry out dividing potential drop, and then the pulse signal is delivered in the voltage follower.The voltage follower output voltage is similar to the input voltage amplitude, and front stage circuits is high-impedance state, and late-class circuit is low resistive state, thereby preceding late-class circuit is played the effect of buffering, isolation, raising load capacity.Voltage by voltage follower comes out carries out the separation of positive negative pulse stuffing signal again.Physical circuit is realized by halfwave rectifier, is specifically seen Fig. 5.

(4) voltage stabilizing and negative circuit

In order to ensure the voltage that inputs to single-chip microcomputer is 5V, and the voltage-stabiliser tube that all adds 5V in two-way carries out voltage stabilizing.Trigger because selected single-chip microcomputer triggering signal is a low level, thus the pulse signal of foregoing circuit output should through phase inverter carry out anti-phase after, just can become the single-chip microcomputer effective trigger signals.Phase inverter uses phase inverter MC14584BCP original paper, and Fig. 6 is two dephased low level signals for the detection signal of detection module output.

(5) hardware of testing circuit is selected

By the function of above-mentioned voltage zero-crossing detection circuit each several part circuit, hardware components can be used four operational amplifiers as can be known, two diodes, two voltage-stabiliser tubes and two phase inverters.Comprehensive above-mentioned functions is in conjunction with practical application, and the hardware components of the voltage zero-crossing detection circuit of this problem design is selected amplifier LM324, diode 1N4148, voltage-stabiliser tube 1N4007 and phase inverter MC14584BCP.Fig. 7, Fig. 8 are respectively amplifier LM324 and phase inverter MC14584BCP structured flowchart.

Control module

(1) MCU:MCU adopts AT89C2051, is the core of control circuit.Built-in 2K FLASH program storage and 128 byte inner RAM.AT89C2051 has 2 I/O mouths, P1 and P3.The P1 mouth drives as the charactron scanner uni.The P3 mouth is as keyboard and pulse control port.

(2) show: 3 eight sections charactrons have been adopted in the display part.Wherein, can show current weld pulse frequency, scope is 1～500Hz; In addition, utilize the decimal point of back two (the 2nd, 3 charactrons) to monitor three kinds of duties of two pulse control bits respectively: the 2nd charactron decimal point Chang Liang (mode1), the 3rd charactron decimal point Chang Liang (mode2), the 2nd, 3 charactron decimal point are alternately lighted (mode3) according to the actual frequency parameter.Can express the running status of impulse controller intuitively, visually.Figure 10 shows decoder driver circuit Figure 11 charactron chip select decoder driver circuit.

(3) keyboard: keyboard is made up of 2 buttons: Reset, Mode.Wherein, Reset is the MCU reset key, makes controller return to default parameters; The Mode key is an impulse controller duty options button, and 3 states are selected in circulation: constant peak value weldingvoltage output (mode1), the output of constant base value weldingvoltage (mode2), peak value-base value pulse weldingvoltage output (mode3).

(4) voltage given: weldingvoltage passes through two independently potentiometers, given crest voltage and base value voltage signal respectively.

(5) interface switch: this part is the electronic switch that one group of photoelectrical coupler constitutes, and its effect is the control signal according to MCU, respectively crest voltage and base value voltage given signal is delivered to the control interface terminal of welding machine.

The voltage effective value of A.C. welder can be got between 35～90v, and frequency is power frequency 50Hz.Cooperate the dc welding machine crest voltage about 28-40v, base value voltage between 16-22v, wire feed rate between 1-15 (m/min), gage of wire can select for use current market common 1.2, the welding wire of 1.6mm, the welding wire trade mark is pressed the actual conditions different choice, can stablize welding.Control module makes the DC pulse frequency identical with a-c cycle by sampling module, and concrete parameter sees the following form.First group and second group of current-voltage waveform figure see accompanying drawing 15 and 16.

Show a part of welding parameter

Claims (1)

1, a kind of double filum narrow interstice alternating-direct current pulse matching electric arc welding method comprises the steps:

Step 1: connection device, regulate the A.C. welder parameter, frequency is power frequency 50Hz, alternating voltage virtual value span 35～90V;

Step 2: the control end of double-wire alternating current-direct current welding controller is connected with the potentiometer given side of dc welding machine;

Step 3: the base value voltage of given DC pulse, scope are 16～22V, the crest voltage of given DC pulse, and peak voltage ranges is 28～40V;

Step 4: two welding wire feeding speed are given, scope 1～15m/min;

Step 5: the test side of controller is connected with A.C. welder, obtains voltage signal;

Step 6: voltage signal resume module after testing is a detection signal, two-way low level signal input control module;

Step 7: calculate through control module, generate the DC pulse control signal and output to control end;

Step 8: the adjustment control pattern makes it to operate in pulsed output mode, the pulse signal of output designing requirement; The pattern of this pulse signal is when the interchange end of welding is positive voltage, the control DC welder produces the output of pulse base value, gravitation minimum between the electric arc that such two electric arcs produce, when alternating current arc is in negative voltage, the control DC welder produces peak value of pulse, repulsion maximum between the electric arc that such two electric arcs produce;

Step 9: welding, electric arc produces the maximum of repelling each other immediately, inhales minimum stress mutually, and electric arc is partial to sidewall to greatest extent and is solved sidewall fusion problem.

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