CN201179586Y - Double-wire AC-DC soldering controller - Google Patents

Abstract

The utility model relates to a double-wire AC/DC welding controller, which belongs to a welding equipment technology. The controller comprises an alternating current detection module and a direct current electric welding machine pulse control module, wherein the alternating current detection module is formed by orderly serially connecting a voltage acquisition filtering circuit, a voltage zero crossing comparison circuit, a differential circuit, a voltage division isolation and half-wave rectifier circuit, and a voltage-stabilizing and inverting circuit; and the direct current electric welding machine pulse control module comprises an MCU (singlechip), a keyboard, a nixietube display, a voltage setter, a photoelectric coupler, and an interface terminal. The controller is to finish the following task: the voltage state of alternating current arc is detected through the detection module, and the pulse output of direct current arc is controlled according to the state of the alternating current arc.

Description

Mariages AC-to-DC welding controller

Technical field

The utility model patent relates to a kind of mariages AC-to-DC welding controller, belongs to the welding equipment technology.

Background technology

Narrow gap welding is the special industrial technology of a kind of high welding quality, high welding productivity, low production cost, and is particularly evident in thick plates.The narrow gap welding connection technology mainly can be divided into two kinds on welding method.A kind of is the narrow-clearance submerged arc welding method, and another kind is the narrow clearance melting electrode electrogas process, but these two kinds of methods all have serious problems, because narrow gap cut is very narrow and very steep, and basic and arc axis keeping parallelism in welding process.Generally speaking, the electric arc periphery that heat input is extremely low also is difficult to affact cut sidewall (to call sidewall in the following text), arc center is just difficult more, the sidewall fusion difficulty that this has just caused narrow gap welding to connect, cause the weldment total quality lowly can't extensive use thus in China, for narrow gap technology can be extensive use of in China, must invent a kind of welding procedure can solve narrow gap welding and connect sidewall and merge problem, University Of Tianjin furthers investigate for this reason, having invented " double filum narrow interstice alternating-direct current pulse matching electric arc welding method " core in this method is exactly, by sampling to the interchange welding process, control dc welding machine and produce corresponding pulse signal, be the AC and DC electric welding machine by the designing requirement output pulse signal, utilize arc force between two welding wires to solve narrow gap and merge inadequate problem.The work of this part is finished by mariages AC-to-DC welding controller.

Summary of the invention

The utility model patent is to implement the nucleus equipment of double filum narrow interstice alternating-direct current pulse matching electric arc welding method, comprises exchanging detection module and dc welding machine pulse control module, and detection module adopts standard interface to be connected with control module;

Above-mentioned interchange detection module is connected in series successively: the voltage acquisition filter circuit, filter clutter; Voltage zero-cross comparison circuit and differential circuit find the alternating voltage zero-crossing point, and it is become peaked wave output; Dividing potential drop is isolated and half-wave rectifying circuit, and the dividing potential drop buffer circuit will extract the positive half-wave signal, and half-wave rectifying circuit is extracted negative half-wave voltage signal; Voltage stabilizing and negative circuit, generation can be controlled the interchange positive half-wave detection signal of module identification;

Above-mentioned dc welding machine pulse control module comprises: MCU (single-chip microcomputer), keyboard, charactron display, voltage setter, photoelectrical coupler, Interface Terminal; Circuit is to be the digital circuit of core with the MCU single-chip microcomputer, and other peripheral hardwares its corresponding pin respectively link to each other.

The task that controller will be finished is that by the voltage status of detection module detection alternating current arc, according to the state of alternating current arc, the pulse of control direct-current arc is exported again.This controller just connects at the direct current welding wire, and workpiece connects under the negative condition, can make DC pulse export base value at the interchange welding wire when being in positive voltage, make electric arc gravitation minimum, when exchanging the welding wire negative voltage, the control direct-current arc produces peak value output, makes repulsion maximum between arc force on the contrary.By strengthening repulsion, two electric arcs are partial to sidewall as far as possible when making welding, have reasonably reduced gravitation simultaneously, make two electric arcs keep certain deflection, thereby have also guaranteed welding penetration.

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 specific embodiment

Controller principle

Contrast the block diagram of controller shown in Figure 1.This controller has adopted modularized design, answer divides two modules, promptly exchange detection module (to call detection module in the following text), 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 single-chip microcomputer (MCU), have 3 mode of operations, can make the source of welding current with constant peak voltage pattern (mode1) respectively, constant base value voltage mode (mode2), peak value-base value pulse voltage pattern (mode3) output can be selected for use in practical operation flexibly.Entire controller has adopted " black box " pattern, and interface is succinct, and the productionization extent of equipment is higher.

Detection module

One, voltage acquisition filter circuit

Contrast Fig. 2, 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 filter circuits, one-level passive filtering and one-level active power filtering.

Two, voltage zero-cross comparison circuit and differential circuit

Contrast Fig. 3,4 will collect the voltage zero-crossing signal of alternating current arc among the present invention, 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.

Three, dividing potential drop is isolated and half-wave rectifying circuit

Contrast Fig. 5, 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.

Four, 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.

Five, the 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 the present invention's 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.

The voltage signal of A.C. welder is input to the 2 ports input that detects interface (TP1) through lead and enters circuit, through the dividing potential drop of resistance R 1 with R2, the elementary filtering of one-level passive filter circuit process that input is made of C1, after this signal is input to by U1A (LM324AN), R3, R4, R5, the one-level active filter circuit that C2 forms carries out filtering, export by the output of U1A after filtering clutter fully, enter the voltage zero-cross comparison circuit of forming by R6 and U1C (LM324AN), signal by U1A output is connected with the positive input terminal of U1C, carry out differential transform through being input to C3 after relatively with zero potential, differential signal is input to R7, R8 carries out dividing potential drop, differential signal after obtaining dividing potential drop between R7 and the R8, be input in the voltage follower of U1B (LM324AN) formation, the amplitude of the approximate input voltage of the output voltage of voltage follower, and prime is high-impedance state, the back level is low resistance state, thereby preceding late-class circuit is played buffering, isolate, improve the effect of load capacity.The filter circuit of being made up of with diode D1 (1N4148) and R9 on the one hand the voltage follow signal of the U1B output signal that filtering will bear half-wave that was connected is isolated reservation positive half-wave signal, the anti-phase mu balanced circuit that the positive half-wave signal is formed via U2A (MC14584BCP), R14, voltage-stabiliser tube (1N4007) connects, final generation can controlled module identification interchange positive half-wave detection signal (end of welding for just), be input to control module single-chip microcomputer P3.1 pin.The voltage follow signal of U1B output on the other hand, will with form half-wave rectifying circuit by R10, R11, R12, U1D (LM324AN) and link to each other and carry out the inverse permutation of positive and negative half-wave, output by U1D outputs to diode at last, the filter circuit that D2 (1N4148) and R13 form, the detection signal that exchanges negative half period (end of welding is for negative) is the most at last sent into the P3.2 pin of control module single-chip microcomputer.

Control module

One, 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.

Two, 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 back two, promptly the decimal point of the 2nd, 3 charactron monitors that respectively three kinds of duties of two pulse control bits: the 2nd charactron decimal point Chang Liang (mode1), the 3rd charactron decimal point Chang Liang (mode2), the 2nd, 3 charactron decimal point alternately light (mode3) according to the actual frequency parameter.Can express the running status of impulse controller intuitively, visually.

Three, keyboard:

Keyboard is made up of 2 buttons: Reset, Mode.Wherein, Reset is the MCU reset key, makes controller return to the default frequency parameter; 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).

Four, voltage given:

Weldingvoltage passes through two independently potentiometers, given crest voltage and base value voltage signal respectively.

Five, interface switch:

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

Control module comprises the control module that is made of MCU (single-chip microcomputer), keyboard, charactron display, voltage setter and photoelectrical coupler, Interface Terminal.It is characterized in that it is the control core circuit that MCU adopts AT89C2051, built-in 2k FLASH program storage and 128 byte inner RAM.An its I/O mouth P1 drives as the charactron scanner uni.Another I/O interface P3 is as keyboard, detection signal input and pulse signal output end mouth; Keyboard Reset, Mode key are formed.Wherein the output of constant peak value weldingvoltage, the output of constant base value weldingvoltage, peak value-base value pulse weldingvoltage output are selected in the Mode circulation; Nixie display adopts 3 eight sections charactrons, and it can represent the pulse frequency of 1-999Hz; The current pattern of decimal point bit representation of double figures sign indicating number pipe wherein, second charactron decimal point Dan Liang represents the current constant base value voltage output mode (mode1) that is in; The 3rd charactron decimal point Dan Liang, expression constant peak voltage output mode (mode2); The decimal point of two charactrons is lighted simultaneously, expression peak value-base value pulse voltage output mode (mode3).Photoelectrical coupler has used optic coupling element TLP521-2, and its characteristics are and control circuit and welding circuit can be isolated fully that the complicated electrical environment when having avoided welding causes interference to controller.Voltage setter is made up of two independent potentiometers; The multichannel interface switch is connected with the given potentiometer terminal board of electric welding machine.

Claims (1)

1, a kind of mariages AC-to-DC welding controller comprises exchanging detection module and dc welding machine pulse control module; Detection module adopts standard interface to be connected with control module, it is characterized in that:

Described interchange detection module is connected in series successively: the voltage acquisition filter circuit, filter clutter; Voltage zero-cross comparison circuit and differential circuit find the alternating voltage zero-crossing point, and it is become peaked wave output; Dividing potential drop is isolated and half-wave rectifying circuit, and the dividing potential drop buffer circuit will extract the positive half-wave signal, and half-wave rectifying circuit is extracted negative half-wave voltage signal; Voltage stabilizing and negative circuit, generation can be controlled the positive and negative half-wave detection signal of interchange of module identification;

Described dc welding machine pulse control module comprises: MCU single-chip microcomputer, keyboard, charactron display, voltage setter, photoelectrical coupler, Interface Terminal; Its circuit is to be the digital circuit of core with the MCU single-chip microcomputer, and other peripheral hardwares its corresponding pin respectively link to each other.

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