CN2040020U

CN2040020U - Silicon-control dc argon arc welding machine

Info

Publication number: CN2040020U
Application number: CN 87204652
Authority: CN
Inventors: 段根明; 谭大斌
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-09-30
Filing date: 1987-09-30
Publication date: 1989-06-28

Abstract

The utility model relates to a control circuit of a thyristor direct-current tungsten electrode argon-arc welder, which is a direct-current arc welder with high efficiency and energy saving. The utility model is composed of a thyristor, a pulse trigger, an arc welding power supply transformer, a rectifying element, an assist arc stabilizing circuit, a high frequency high voltage arc striking circuit, a feedback network and a PID regulator. Because a thyristor power element is used as a switch to be connected with a power supply, the no-load loss of the welder is avoided, and meanwhile, the voltage adjustment of the thyristor can change the current standard of the welder to increase the efficiency of the complete machine. The utility model uses an integrated circuit as the pulse trigger and has the advantages of simplicity, stabilisation and reliability.

Description

Silicon-control DC argon arc welding machine

The utility model is a kind of control circuit of controllable silicon direct current tungsten argon arc welding machine, can be used for the direct current tungsten argon arc welding machine of efficient energy-saving safe type.

The direct current tungsten argon arc welding machine main transformer floating voltage that generally uses is between 70～85V at present, and copper material that transformer is used and silicon steel sheet expend very big, cause the transformer heaviness, the more important thing is that no-load current has several amperes even tens of ampere.Because welding machine belongs to intermittent duty, transformer coil is switched on for a long time, and a large amount of electric energy is consumed when zero load, has wasted, and moves uneconomical.

In order to save electric energy, prior art usually from reducing power supply no-load consumption, take to be connected in series electric capacity in the main power circuit step-down with do reactive-load compensation or modes such as electronic control circuit, high frequency electricity-saving appliance, its executive item be unable to do without A.C. contactor and makes isolating switch, noise is arranged when working owing to A.C. contactor, consumed power own, the ac contactor contact time response velocity fails is low in addition, start frequently, the contact wearing and tearing are big, so its life-span is not long.

The purpose of this utility model provides the high direct current tungsten electrode arc-welding machine of a kind of power saving rate, can cut off input current automatically when unloaded, the starting the arc of switching on fast again during load, and welding characteristic is good, noiselessness, nothing wearing and tearing, and is light economical and practical.

The utility model is made up of controllable silicon, pulsed triggering circuit, arc welding transformer, auxiliary arc stabilizer, high-frequency and high-voltage arc initiation device, PID adjuster and current feedback, the controllable silicon that wherein is serially connected in electric power loop had both been made the noncontacting switch of main circuit of the welding machine, was again the welding current regulating element.For the arc starting performance of assurance welding machine is good, provide the floating voltage stabilising arc of one group of 80V by transformer B2.The tungsten argon arc welding machine is by high-frequency and high-voltage noncontact striking, and the electric arc mode of igniting is different from general direct current-direct current (AC-DC) welding, and the operation of this welding machine is by an interlock button K, connects high-frequency arc ignition circuit, arc static circuit and pulsed triggering circuit simultaneously respectively.For making welding current stable better, control characteristic is good again, and this welding machine had both made output and input carry out closed-loop control through current feedback network and PID adjuster, also whole welding machine was carried out overcurrent protection.

Further formation of the present utility model is the direct current output loop to be provided behind the 80V voltage commutation that is provided by B2 make unloaded stabilising arc and use.The secondary work voltage of main transformer is reduced to 20～35V by common 60～85V, and main transformer voltage output is low, and that the number of turn is a half is many, the material of copper material and silicon steel sheet expends too big decline, and volume and weight is general direct current-direct current (AC-DC) welding, 1/3-1/2.

The utility model has been taken all factors into consideration the no-load consumption of eliminating welding machine, the power attenuation and the material that reduce transformer expend, avoid and overcome the deficiencies in the prior art from key link, concerning factory, reduced complete machine production cost expense, the butt welding machine user has saved the utilization and operation expense, can obtain than the significant social economic benefit.

Now in conjunction with the accompanying drawings utility model is described:

Accompanying drawing 1 is a functional-block diagram of the present utility model;

Accompanying drawing 2 is embodiment schematic circuits of the present utility model.

With reference to Fig. 1, the elementary winding voltage input of SCR control and adjusting arc welding transformer, its secondary voltage is by bridge rectifier, and a 80V voltage that is attempted by the transformer B2 of output loop is made striking usefulness as floating voltage stabilising arc, while high-frequency arc strike device serial connection at output loop.Form current feedback system jointly by current transformer and PID adjuster, silicon controlled toggle is regulated controlled the silicon controlled angle of flow, thereby regulate the complete machine welding current.

With reference to Fig. 2, transformer B1 is a main power source that output voltage is 20～35V, through bridge type silicon rectifying tube D17---20 are rectified into direct current, L1 is the low frequency filtering inductance coil, it can improve dynamic characteristic of arc, the connection of welding current and adjusting are by being serially connected in the thyristor controlled of transformer B1 primary return, thyristor is explained door greatly as Current Control here, during its full conducting, almost all inflow transformer B1 is elementary for supply voltage, and the B1 secondary voltage is the highest, and welding current reaches maximum output, when closing, controllable silicon is cut off between the elementary and power supply of transformer B1, a few volt drain voltages are arranged on the plumb joint, and the operator can carry out other operation safely.

Integrated package NE555 is a kind of time-base integrated circuit, is connected into the monostable oscillator, selects that timing element resistance R 6---the time constant of 11W1 and capacitor C 1 makes it to equal 10 milliseconds, is half wave period of 50 all alternating currents.Diode, D1-4 are with 60V voltage commutation, voltage-stabiliser tube slicing, and the amplitude of becoming is the trapezoidal wave of 5～6V, and also be 10 milliseconds trapezoidal wave period.The 2. pin that flows to integrated package NE555 is as synchronous trigger voltage.Like this, make the wave of oscillation of NE555 and main power source frequency synchronously strict.By-pass cock K2 can change the width of pulse-triggered waveform, just changes phase shift range.From the output of 3. pin is that one-period is 10 milliseconds but the square wave of pulse width variation, what obtain every straight effect, transformer B3 through capacitor C 3 is a steep pretty spike, giving bidirectional triode thyristor, decision bidirectional triode thyristor conducting and close and size, the thyristor of the angle of flow are a thing dual-purpose, diode D1 herein through time grade coupled---D4 is the triggering signal rectifier of NE, and diode D5～D8 is the power rectifier of NE555.

The 80V voltage that is attempted by dc power output is that the floating voltage of bonding machine is made stabilising arc usefulness, and resistance R 12 is its current-limiting resistances.The tungsten argon arc welding machine is serially connected in major loop by high-frequency and high-voltage generator through transformer B4 in when work, punctures air-gap between tungsten electrode and the workpiece and striking.For preventing that high-frequency and high-voltage from sealing in rectifier, transformer and other circuit are formed the towering type bypass of high frequency by capacitor C 8, C9 and high frequency choke coil L2.

Diode D24, D25 resistance R 13, R16, R15 capacitor C 7, C5, C10 at this all as over-voltage protection element.

For further improving welder performance; improve the welding quality; butt welding machine overcurrent protection simultaneously; the utility model has adopted a cover closed-loop control system; current transformer FI and PID amplifier and pulse trigger interconnects, current transformer is from the secondary sampling current of transformer B1, become voltage in resistance R 14 are through diode D13-16 rectifying and wave-filtering and the input of PID adjuster homophase, connect with integrated package NE555 Timing power supply reversed polarity.When welding machine is started working, less feedback signal of welding current and PID output are also less, the trigger impulse reach controllable silicon of pulse trigger passes through bigger voltage with the less angle of flow, make welding current become big, when welding current is excessive, electric current by feedback is also big, can offset the growth of above-mentioned electric current through the control and regulation circuit, so regulate by this cover Current Negative Three-Point Capacitance system, can make the welding machine operating current reach a kind of poised state of adjusting in advance automatically, the characteristic that acquisition is fallen suddenly also tends towards stability.The operating current of welding machine is by the direct reading of ammeter, and W1 makes work electric current microcall.

The welding machine operation is by button switch K 1 control, and when unloaded, K1 disconnects, and controllable silicon has turn-offed major loop, floating voltage is cut off by button switch K 1-2, and hf arc starter is cut off by button switch K 1-3, and the operator is fool proof.Whole welding machine has only transformer B2 energising operation, though pulse trigger work, whole welding machine current sinking only several milliamperes of electric currents wastes, welding press during work button switch K 1 at this moment button switch K 1-1 the pulse signal is added to bidirectional triode thyristor control extremely goes up and connect major loop.Button switch K 1-2 is added on the plumb joint button switch K 1-3 to unloaded stabilising arc voltage the power connection of high-frequency and high-voltage generator, and the electric arc welding machine that ignites enters running status.

Claims

1, a kind of controllable silicon direct current tungsten argon arc welding machine, it is by controllable silicon, pulsed triggering circuit, arc welding transformer, arc stabilizer, high-frequency and high-voltage arc initiation device, PID adjuster and current feedback are formed, and it is characterized in that regulating with controllable silicon rate of doing work switch and electric current, and are serially connected in the primary return of arc welding transformer.

2, controllable silicon direct current tungsten argon arc welding machine according to claim 1 is characterized in that pulse trigger mainly is made up of time-base integrated circuit NE555.

3, according to claim 1,2 described controllable silicon direct current tungsten argon arc welding machines, the adjusting that it is characterized in that welding current changes the silicon controlled angle of flow by a gear change-over switch K2 and resistance R 6～R10 and realizes.