CN87101347A - The high-voltage inverted electric welding machine of mining transistor DC - Google Patents

Abstract

The high-voltage inverted electric welding machine of mining transistor DC, be a kind of be the microminiature portable high frequency pulsed arc welder that core is made with transistor large power supply that can inversion under 800 volts of high direct voltages.180 volts to 800 volts of input direct voltages, welding current 10 peaces are to 450 peaces, 5 volts of floating voltages, 12 kilowatts of power outputs, pulse frequency 16 to 30 kilocycles; Possess pulse current, voltage, frequency, pulsewidth is adjustable and constant current, constant voltage welding external characteristics; Have unloaded economize on electricity, electroshock-proof function; Its arc stability, splash little, moulding is attractive in appearance and fusion penetration is big, efficient is high, welding conditions are easy to accurate control, belongs to a kind of energy-efficient high-quality new welder.

Description

The invention belongs to the electric welding equipment of transistor contravariant.

Down-hole, mine main road haulage instruments such as present domestic colliery, metallurgy, chemical industry are still based on stringing electrical locomotive.Because as the direct current supply line that drives stringing electrical locomotive power, its positive pole is a trolley line, negative pole is the track in the tunnel, and track system adopts clamping plate, screw attachment to fix, and contact resistance is big.Reach at down-hole main road haulage circuit under the situation of several kilometers even tens kilometers, the voltage drop that is produced because of the track contact resistance have up to more than 100 volts, so not only cause very big electric energy loss, seriously disturb underground communica tion but also can produce stray electrical current.National for this reason Ministry of Coal Industry requires underground orbit all not have seam welding, but because down-hole main haulage roadway distance, 220 volts of single phase alternating current power supplies and 380 volts of three-phase alternating-current supplies are difficult for solving, and existing various conventional electric welding machines can't be used in big lane in the down-hole.It is reported that the domestic producer that has aims at the dc motor band generating set electric welding machine that the big lane of mine produces, weigh 1.1 tons, carrying is used very inconvenient.And several thyristor inversion electric welding machines that occur recently, what have still weighs 180 kilograms, though have gentlier, the output welding current is little, can not satisfy use.The ubiquity volume is big, and noise is big, disturbs greatly, and efficient is low, poor reliability, shortcomings such as welding characteristic difference.

It is investigated on principle with the immediate prior art of the present invention be the E-300-P type TIG transistor arc welding power source that U.S. ASTRO-MATIC company produces, and the transistor contravariant AC welding power source that occurs on the overseas market.(the visible Tsing-Hua University of its circuit where in hall chief editor " Arc Welding Rectifier and control " book in 118 pages to 119 pages Fig. 3-12 to Fig. 3-15).Though prior art and the present invention belong to the transistor pulsed arc-welding power source, the former of prior art is the current cut-off reaction type transistor pulsed arc-welding power source of working under 50 volts of low pressure; The latter of prior art is the AC arc welding power source of 3 kilowatts of output power inverters after the single phase alternating current power supply rectification; The present invention is applied in down-hole, the mine Da Xiang that lacks single-phase or three-phase alternating-current supply, directly utilizes stringing electrical locomotive to carry out the pulsed arc-welding power source of inversion with the trolley line high direct voltage.

Compared with the prior art, dc inversion operating voltage of the present invention is up to 800 volts; The grid voltage change scope is big, is 400 volts～800 volts; (prior art operation DC voltage maximum only is 300 volts, voltage change is generally ± and 10%), power output is big, is 12 kilowatts; (3 kilowatts of prior arts) etc.So the present invention not only has obvious unique technique feature on circuit design, and on serviceability compared with the prior art great substantial difference is arranged also.

At the problems referred to above, the objective of the invention is from the welding of big lane, down-hole, mine track and these characteristics of maintenance of equipment, utilization new device and electronic technology development are applicable to the big lane enforcement in down-hole arc welding, and do not need AC power, a kind of volume that directly utilizes the trolley line high direct voltage to supply with as power supply is little, in light weight, be easy to carry, easy to use, welding performance is good, the novel inversion welding machine of safe and reliable transistor.

The present invention realizes as follows: the present invention is mainly by power supply input circuit, auxiliary inverse power supply, 200KHz high-frequency arc ignition circuit, 12 kilowatts of four most of compositions of high-power inverter.The present invention is described in further detail below with reference to accompanying drawing.

Accompanying drawing 1 is the present invention's block diagram.A is the restriction surge voltage among the figure; the surge current input filter circuit; B is an auxiliary inverse power supply; C is a main control circuit; D is frequency levelling and dead band control circuit; E is the high-speed high-power drive circuit; the routine for this reason voltage generation circuit of F; G is the high power contravariant circuit; H is a welding output circuit; I is the welding current testing circuit; J is welding current control and display circuit, and K is a weldingvoltage control display circuit, and L is unloaded control economize on electricity and the protection against electric shock circuit of detecting; M is high power transistor group temperature detection and overheating protection circuit; N is a high power transistor group over-voltage and over-current high speed holding circuit, and O is an arc ignition control circuit, and P is the striking drive circuit; Q is the high-frequency arc strike circuit for power conversion; R is a striking variable power supply circuit, and S is striking power output peak value type sample circuit and Power Limitation circuit, and T is striking frequency levelling circuit.

Accompanying drawing 2 is input direct voltage 400V～800V or 180V～360V; power output is 12KW; zone of welding current is 10A～450A; maximum weld electric current 500A; floating voltage 5V; striking voltage 60～80V; welding main pulse power frequency is 16KHz～30KHz; striking and arc maintenance pulse current frequency are 100KHz～200KHz; overall efficiency reaches more than 90%; have constant current and constant voltage welding characteristic, have the transistor inversion welding machine electrical schematic diagram of unloaded economize on electricity and electrical shock protection safety function.Because of the circuit complexity, open on the figure so be painted on 2a～2e5 respectively.

Now be example, set forth principle, formation and the function of each several part circuit of the present invention with Fig. 2.

Input pressure limiting, limiting filter circuit (A): by YM ₁, L ₃, SCR ₁, R ₁, C ₄～C ₇Form in circuit.Piezo-resistance YM ₁Moment surge voltage to the electrical network input absorbs pressure limiting.Resistance R ₁Can stop in the moment of starting shooting and form the generation of very big surge current because of filter capacitor is charged.After the electric capacity charging finished, auxiliary inverse power supply (B) output voltage was through D ₁₇Rectification, C ₃After the filtering, trigger SCR ₁; SCR ₁After the conducting with R ₁R in operate as normal is avoided in short circuit ₁Produce excessive power consumption.Choking coil L ₂With capacitor C ₄～C ₇Form filter circuit, when preventing electric welding machine work, circuitry and the mutual interference of importing between the electrical network mutually; While C ₄C ₆With C ₅C ₇The series connection dividing potential drop provide midpoint potential for semibridge system high power conversion level again.

Auxiliary inverse power supply (B): by integrated switching circuit IC ₁, BG ₁～BG ₆, D ₂～D ₂₆, B ₁～B ₃, R ₆～R ₂₇, C ₈～C ₁₉Deng composition.After connecting power supply, by R ₆～R ₈, D ₃, D ₄, SCR ₂The startup power supply of forming is supplied with integral control circuit IC ₁(SG3524) reach by BG ₁～BG ₄Deng the low tension of the drive circuit of forming about with 20V.At this moment IC ₁11,14 pin alternately export square-wave pulse, after drive circuit amplifies, by B ₁, B ₂Secondary output; Again through D ₇～D ₁₂The anti saturation circuit of forming promotes injectron BG ₅, BG ₆Work.Thereby make high frequency transformer B ₃Secondary induction goes out corresponding pulses voltage, again through D ₁₈～D ₂₅After the rectification, form various low-voltage directs; Supply with the main control circuit (C) of high power contravariant level respectively, required low-voltage dc power supplies such as high-speed high-power drive circuit (E) and arc ignition circuit.

Main control circuit (C): by integrated switching circuit IC ₂, D ₂₆, D ₂₇, R ₃₅～R ₄₂, C ₂₀～C ₂₃Deng composition.

Frequency levelling circuit and dead band control circuit (D): by BG ₇, R ₂₈～R ₃₁, W ₃And BG ₈, R ₃₂, R ₃₃Deng composition.

IC in the main control circuit (C) ₂Adopt integrated switching circuit SG1524.C ₂₁With R ₃₀, R ₃₁, W ₃Frequency of oscillation Deng decision SG1524.Regulate W according to the welding needs ₃Can align output pulse frequency.IC ₂11,14 pin alternately export square-wave pulse excitation high-speed high-power driving stage (E).IC ₂4 pin be the input of its internal current restriction operational amplifier, control the input feedback voltage of 4 pin and can control IC ₂The width of output pulse has just been regulated IC ₂The output duty of ratio.The present invention utilizes IC ₂The pulse-width controlled characteristic of 4 pin is regulated as complete machine output welding current and the feedback of constant current output control is imported control end.IC in like manner ₂1 pin be the inverting input of its builtin voltage operational amplifier, control the also corresponding IC that regulated of 1 pin input feedback voltage ₂The output duty of ratio.Utilize this characteristic, the present invention realizes the FEEDBACK CONTROL end of constant voltage welding output as complete machine.

BG7 and R ₂₈, R ₂₉Effect be to regulate IC automatically with the variation of line voltage ₂Output pulse frequency.The purpose of levelling frequency is in order to keep the complete machine output voltage not produce too big variation because of raising significantly of electrical network input voltage.Generally speaking, because of the effect of constant-current control circuit, high-power output stage (G) output pulse width narrows down with the rising of electrical network input voltage, and promptly dutycycle reduces.Consequently dutycycle is more little, and the harmonic content in the output pulse is big more.This not only can cause bigger interference to electrical network, and the inversion loss also can correspondingly increase.The effect that this frequency is aligned circuit automatically is: when line voltage raise, it made IC ₂Output frequency increases; And the welding output loop, because of choking coil L ₁₇Striking transformer B ₈The secondary loop inductance becomes big mechanism to the high-frequency impulse impedance, and the output weldingvoltage can not raise because of line voltage; Its result avoids relatively aligning dutycycle merely and increases the weight of to export higher harmonic components like this, increases the shortcoming of loss.

The effect of dead band control circuit is when line voltage raises, BG ₈Impedance reduces, and makes IC ₂Output pulse dead band is strengthened relatively.Thereby avoid conscientiously causing IC because of frequency raises ₂Output, high-power drive circuit, composite factors such as high power valve group base stage recombination current cause relative dead zone to reduce, and might make inverse cascade produce " common conducting " and damage the harm of high back-pressure high power valve group.

High-speed high-power drive circuit (E): by IC ₃, IC ₄, BG ₉～BG ₁₈, D ₂₈～D ₂₉Deng composition.IC wherein ₃, IC ₄Adopt the good device of integrated circuit type high-speed light coupling device GO710 effective transmission pulse control signal as carrying out High-Voltage Insulation to isolate between control circuit (C) and the drive circuit (E).General photo-coupler is because transmission delay big (reaching a few microsecond to tens microseconds), especially its output pulse t _rAnd t _fReach 2～4 μ S; The harm that in the high frequency half bridge formula power transfer of 16KHz～30KHz, can significantly reduce Dead Time and produce " common admittance ", make it can not normal reliable work.And integrated optical coupler transmission delay little (300ns following), output is risen, fall time t _r, t _fAll less than 150ns.Therefore it can cooperate high-speed transfer IC with high speed V-MOS high power valve ₂The control signal of sending; And can not produce any influence to Dead Time, guarantee to encourage high-power switching stage reliably working.

The V-MOS power field effect pipe is a kind of majority carrier new device.Its input impedance height, power gain is big, and do not have normal transistor intrinsic few son storage effect; Thereby switching speed several to tens nanoseconds between, fast 10～200 times than normal transistor.Therefore the present invention adopts V-MOS pipe new device to undertake high-speed high-power and drives task, not only can simplify circuit design greatly, and routine therewith voltage generation circuit combines and forms the key factor of decision high-power inversion success.

This routine voltage generation circuit (F): by D ₁₉～D ₂₀, D ₂₂, D ₂₃, D ₃₄～D ₃₇, B ₆, L ₅, L ₇, L ₁₁, L ₁₂, C ₁₅, C ₁₇, C ₂₈Deng composition.Auxiliary inverse power supply (B) medium-high frequency power transformer B wherein ₃Secondary output is through D ₁₉～D ₂₀And D ₂₂～D ₂₃Rectification L ₅, C ₁₅And L ₇C ₁₇Supply with driving stage after the filtering with the low-voltage, high-current accessory power supply; Make driving stage finish small-power excitation task.And when the welding current increasing needs high-power output, by current transformer B ₆Output and the directly proportional voltage of power output are again through D _34～35, D _36～37Rectification, L ₁₁C ₁₅, C ₂₈L ₁₂Supply with up and down V-MOS high power valve BG in two groups of drive circuits after the filtering respectively ₁₀, BG ₁₅And current-limiting resistance R ₄₇, R ₅₁Thereby, form the direct proportion high-power driving electric current of following the power output size variation.Can make high-voltage inverted transistor keep shallow saturated or critical saturation state all the time like this, thereby help dwindling waiting time, improve inversion efficiency.

V-MOS manages BG in the drive circuit (E) in addition _12～13, BG _17～18, BG ₁₁, BG ₁₆Effect be: when driving pulse finishes, BG ₉, BG ₁₄Be respectively electronegative potential, BG _12～13Or BG _17～18End rapidly, all emitter stages in the high power transistor group are opened a way at a high speed, and while BG ₁₁Or BG ₁₆Rapid saturation conduction, next quick extract phase is answered the minority carrier in the high-voltage high-power transistor base stage.The method of the high-voltage inverted pipe of this shutoff not only can shorten its waiting time and downslope time greatly, improves switching speed greatly; But also can avoid conventional reverse bias to turn-off the harm that mode easily produces second breakdown, make same device can be applied to the operating frequency of higher voltage and Geng Gao.

High power contravariant circuit (G): by high back-pressure high power transistor BG ₂₀～BG ₃₁, R ₅₂～R ₆₂Deng composition.Itself and high-power high-frequency transformer B ₅, C ₂₆, filtering dividing potential drop capacitor C ₄～C ₇Deng the strong semibridge system circuit for power conversion of formation anti-unbalance ability.R wherein ₅₂～R ₆₃Play the current-sharing effect, C ₂₆Play balanced compensated effect.

Welding output loop (H): by high-power transformer B ₅, striking output transformer B ₈, choking coil L ₁₇Deng composition.B ₅, B ₈Secondary output series connection, 200KHz pulse and 20KHz pulse shaping superposition are modulated, help striking and welding arc smooth combustion.And L ₁₇Play multiple function at this: the one, cooperate the formation dropping characteristic with constant-current control circuit; The 2nd, limit the instantaneous short circuit electric current, remedy the deficiency of constant-current control circuit response time; The 3rd, help welding current waveform continuously, striking and smooth combustion; The 4th, cooperate frequency levelling circuit (D), when raising, plays the electrical network input voltage regulated output voltage effect.

Welding current testing circuit (I) and control display circuit (J) thereof: by current transformer B ₉, D _51～52, L ₁₆, L ₁₉, C _37～39, R ₇₅～R ₈₃, W ₆, K ₂Form.Welding current is by B ₉Induce relevant voltage through D ₅₁, D ₅₂Rectification L ₁₆, L ₁₉, C _37～39Be added to R after the filtering respectively ₇₅～R ₇₉, R _80～83On the divider resistance.Welding current is by K switch ₂Divide the fourth gear conversion from R ₇₅～R ₇₈Last acquisition sampling voltage is again through W ₆Add to master controller IC after the fine tuning ₂4 pin form welding current control voltage, and ammeter A then shows corresponding welding current.Coaxial switch K ₂Fourth gear K is arranged _2aAnd K _2bControl welding current sampling scope, K _2CFor this grade electric current shows.

Weldingvoltage control display circuit (K): by D ₅₃, R ₃₄, R ₁₁₅, R ₁₁₆, C ₅₀, C ₂₃, W ₄Deng composition.Weldingvoltage is through D ₅₃Rectification C ₅₀After the filtering, through R ₃₄, W ₄Add to IC ₂1 pin is regulated W ₄Can regulate the size of output weldingvoltage, and by voltmeter V ₂Show.

Unloaded economize on electricity protection against electric shock circuit (L): by C ₃₃, B ₇, C ₃₄, QL ₂Etc. no load detection circuit and BG ₁₉, D ₄₂, K ₃, R ₆₈Form Deng control circuit.When welding circuit zero load or contact resistance during greater than certain setting, testing circuit output voltage deficiency is so that BG ₁₉Conducting.Thereby auxiliary inversion electric current output 20V DC voltage is through R ₆₈, D ₄₂Add to IC ₂10 pin make IC ₂Close the output pulse, the high power contravariant level is not worked.At this moment the whole power consumptions of electric welding machine are less than 10W, and power savings is remarkable; Arc ignition circuit is also worked through B under 20V low pressure simultaneously ₈The voltage of secondary step-down output only has about 5V, and is fool proof to the people.

The sensitivity of this machine design anti-electric shock apparatus divides 4 grades in addition: 1000 Ω, 100 Ω, 10 Ω, 2 Ω, pass through K switch ₃Control, the welder can select according to the concrete operations situation.

Temperature detection and overheating protection circuit (M): by IC ₅, D ₄₃, QL ₁, C ₃₀And electric fan D and heat-pipe radiating apparatus composition.IC wherein ₅For temperature detection integrated circuit AN6701, be fixed on the heat abstractor of high power contravariant pipe group.When the high power valve group causes high temperature (more than 70 ℃) because of the accident reason, IC ₅Output greater than 10V voltage with Zener diode D ₄₄Puncture; Through D ₄₃Add to IC ₂10 pin, the output of main control circuit (C) is closed; Thereby the protection high power transistor does not damage because of overheated.In order better high power contravariant pipe group being dispelled the heat, to make it reliably working, and compress radiator volume, weight; This machine adopts the novel heat sink large power heat pipe to dispel the heat.Heat pipe is the high heat transfer element of a kind of heat transfer efficiency, and its capacity of heat transmission is than contour tens times of excellent heat conductivity body silver, copper, the aluminium that it is conventionally believed that, even hundred times.Therefore adopt the new heat pipe radiating mode to alleviate heatsink weight widely and improve heat dispersion.Transformer B in addition ₅Secondary one group of winding output is through full-bridge QL ₁Rectification, C ₃₀Supply with the fan electromotor electricity consumption after the filtering, cooperate with heat pipe and form the forced air cooling cooling system.The remarkable advantage of this system is that volume is little, in light weight, excellent radiation performance, can guarantee high power contravariant pipe group reliably working at a lower temperature, and the noise reduction electricity-saving function is arranged.

Over-voltage and over-current high speed holding circuit (N): by YM ₄, YM ₅, R _64～65, C ₂₇, C ₂₉, IC ₆, BG ₃₂BG ₃₃Deng composition.C wherein ₂₇, R ₆₄, C ₂₉, R ₆₅Play peak voltage and absorb and the VA characteristic curve correcting action piezo-resistance YM _4～5The superpressure peak voltage is absorbed restriction, R ₇₃Be high power contravariant pipe group overcurrent sample, and add to F3140 single supply op IC ₆3 pin.When producing, after arithmetic unit amplifies, triggers over-current signal BG ₃₂BG ₃₃The high speed circuit of forming is by BG ₃₂The output high potential is to IC ₂10 pin, make IC ₂Close rapidly, thus protect conscientiously the high power valve group not can because of moment overcurrent damage.

Arc ignition circuit (O, P, Q, R): by the SG1524 IC ₇The control circuit of forming (O), V-MOS manages BG ₃₇, BG ₃₈, R ₁₀₁～R ₁₀₄The drive circuit of forming (P), V-MOS power tube BG ₃₉～BG ₄₂, transformer B ₈The push-pull type circuit for power conversion (Q) and the D that form _24～25, D ₃₈～D ₄₀, C ₃₂Several most of compositions such as the variable power supply circuit of forming (R).When zero load, high-power level is not worked.Arc ignition circuit is by auxiliary inverse power supply D ₂₄D ₂₅L ₉Output is through D ₄₀L ₁₄Supply with 20V low-tension supplies at different levels respectively.Arc ignition circuit is all under low pressure worked like this, through B ₈Output 200KH25V pulse signal is as zero load and protection against electric shock sensed signal sources.High power contravariant level work when welding, B ₅Secondary winding output is through D ₃₈D ₃₉Rectification, L ₁₂, C ₃₂Form the above high pressure of 200V after the filtering and add to B ₈The centre cap of elementary winding is supplied with striking power conversion stage high pressure, makes B ₈Secondary output high-frequency and high-voltage provides striking voltage and back ground current for normal welding.

The levelling of striking frequency (T) and Power Limitation circuit (S): by BG ₃₄～BG ₃₆, D ₄₆, R ₈₄～R ₉₂, R _97,98, W ₇W ₈Deng composition, R wherein ₈₄D ₄₆, BG ₃₄, R ₈₇Form the peak value type sample circuit in the Power Limitation circuit (S).At R ₈₇The direct current signal of last acquisition can direct proportion in the operating current or the power of power conversion stage.Therefore with this signal through R ₈₈, W ₇And C ₄₀, C ₄₃Filtering delay-time adds to IC ₇4 pin are after the power output that can control arc ignition circuit is amplified in the computing of its internal current restriction operational amplifier perfectly.Export the more powerful requirement of high pressure in short-term when this time-delay control function promptly can satisfy striking, can satisfy the requirement of pressing smaller power in the required output of normal welding arc maintenance again, and excess load and damaging when protecting power conversion stage V-MOS pipe to be unlikely to long again.Frequency levelling circuit (T) is by BG ₃₅BG ₃₆R ₉₇W ₈Form.W ₈Behaviour wage adjustment positive frequency potentiometer, this partial circuit is controlled by the Power Limitation circuit.Its effect is: during striking, make the circuit output pulse frequency low slightly; L like this ₁₇It is relatively low to present impedance, and striking voltage is improved.And when normally welding, the arc ignition circuit frequency is raise, L ₁₇Present impedance and strengthen, high-frequency output voltage reduces relatively.Do striking like this, the arc maintenance reaction speed is fast, exports pulse duty factor by levelling and carries out Power Limitation efficient height than simple, and is stable and reliable for performance.

Again with whole working, further specify the relation between each circuit below.

During use the power line positive pole is ridden on the trolley line of big lane, down-hole, negative line is connected on track or the workpiece.Connect power switch K ₁, the DC high-voltage power supply positive pole is through D ₁, L ₂, R ₁Add to C ₄～C ₇On the electric capacity, behind capacitor filtering, add to auxiliary inverse power supply (B) and high power contravariant level (G) BG respectively ₂₀～BG ₃₁On.At first auxiliary inverse power supply is started working, and exports various low-voltage DCs and supplies with arc ignition circuit (O, P, Q, R) and governor circuit (C) IC respectively ₃With high-power driving level (E) and each related detection circuit.

At this moment arc ignition circuit is all worked under 20V low pressure, through B ₈Secondary output 5V, the 200KHZ pulse square wave adds on the welding rod.If welding rod does not contact any load less than 1000 Ω (being that unreal welding connects), the output of no load detection circuit no signal, IC ₂Be blocked.Complete machine was in and waited for electricity-saving state this moment, and full machine power consumption is not more than 10W.Suppose that at this moment the welder is not intended to touch soldering tip and since human body resistance much larger than 1000 Ω (if when environment is too moist, can be with electrocution-proof switch K ₃Beat to corresponding, make the human body contact resistance much larger than this grade sensitivity than the low resistance shelves), main control level (C) is not worked, and 5V low pressure can not produce any danger to human body.

When snapping work if desired, at first according to welding needs with current-controlled switch K ₂Beat to corresponding shelves.At this moment welding rod one contact workpiece, no load detection circuit (L) is just exported high potential and is made BG ₁₉Conducting is saturated, D ₄₂End BG ₄₃End, through D ₂₇, C ₂₀Be connected to IC ₂9 pin form soft start, IC ₂Output pulse width is by narrow broadening gradually, to avoid B ₅It is saturated and damage high-voltage inverted pipe to issue magnetisation at high-power moment impact.At this moment high-voltage inverter circuit changes operate as normal over to, D _38～39Rectification goes out the 200V high pressure through B ₈The primary center tap adds to the striking power converter, makes B ₈Secondary output striking high-frequency and high-voltage.QL ₁Output voltage makes electric fan work, and ratio-voltage produces circuit (F) output and supplies with high-power drive circuit (E) with the directly proportional voltage of electric current, makes high power valve BG ₂₀～BG ₃₁Reliable and stablely carry out work.

At this moment striking voltage and main output pulses voltage superposition mutually forms the High Frequency Of Recombination pulse current, makes welding arc no matter can both be easy to striking, smooth combustion under large and small welding current situation.Because IC ₂The gain of internal current operational amplifier is higher, adds the cooperation of high-speed high-power drive circuit and other relevant circuit, and welding current can be controlled comparatively accurately.No matter welding rod is long and short, even produces the molten drop short circuit, also can guarantee to fall suddenly external characteristics of constant current.

If need the constant voltage welding under the specific condition, can regulate W ₄Control IC ₂Obtain stable constant-voltage characteristic, and find out needed weldingvoltage from voltmeter.

Needn't shut down when changing welding rod, as long as welding rod is left welding work pieces, no load detection circuit is no-output just, BG ₁₉End, draining is high potential, IC ₂Promptly be blocked no-output, full machine is in the economize on electricity stand-by state automatically.

The present invention has adopted the novel electron device, from practicality various control protection electric circuits is arranged on circuit design, and perfect performance is easy to operate, safe and reliable.Its main feature has:

One, designed by integrated circuit type high-speed light coupling device, V-MOS FET, ratio-voltage produce the peculiar comprehensive high-speed high-power drive circuit that circuit and emitter stage open circuit cut-off method etc. are formed.This drive circuit advantage compared with the prior art is:

1,,, obtains fine control performance so it can export pulse wave high-speed driving high power contravariant pipe in strict accordance with control circuit because integrated circuit photo-coupler and V-MOS FET all are high speed devices.

2, produce circuit by ratio-voltage and provide the ratio drive current, make high-voltage inverted pipe keep shallow saturated or critical saturation state all the time, thereby help shortening waiting time, improve inversion efficiency, the control characteristic when improving small-power output to driving stage.

3, the employing emitter stage is opened a way and is not had the low internal resistance V-MOS pipe of the reverse bias method shutoff inversion large power pipe of extraction base stage minority carrier rapidly, not only can shorten the waiting time and the downslope time of inversion pipe greatly, improves switching speed greatly; But also can avoid conventional reverse bias breaking circuit easily to produce secondary-breakdown phenomenon, make same device can be applied to higher operating voltage and the operating frequency of Geng Gao.In a word, just because of the above-mentioned comprehensive premium properties of drive circuit of the present invention, the technology utilization of high-power inversion is achieved.

Two, designed overvoltage, overcurrent and protected overtemperature protection at a high speed, align automatically in the dead band, and frequency is aligned automatically, and the general protective circuit that soft start etc. show unique characteristics guarantees the reliability service of high-power inverse cascade.

Three, designed and can adapt to input direct voltage 180V～360V, 400V～800V wide variation, welding current 10A～450A regulate and can guarantee the integrated control circuit of output constant current or constant-voltage characteristic significantly.

Four, designed protection against electric shock circuit and the unloaded economize on electricity integrated control circuit that shows unique characteristics.

Five, levelling of good multifunctional high frequency arc ignition circuit and frequency thereof and Power Limitation circuit have been designed.

Six, adopt the new heat pipe heat abstractor, not only compressed machine volume widely, weight reduction, and also whole aircraft reliability is improved.

The present invention can be applicable to big lane, down-hole, all kinds of mine high direct voltage from 180V～360V, the specific (special) requirements that 400V～800V changes significantly, and keep the output welding current very stable.It is compared with existing mine thyristor inversion electric welding machine, it is very stable to have welding arc, it is little to splash, and fusion penetration is big, and it is attractive in appearance to be shaped, no arc blow phenomenon, welding current control is accurate, and external characteristics of constant current is good, and compensation performance was good when line voltage changed significantly, disturb little to the input electrical network, noiseless (controllable silicon formula frequency is low, and noise is big) electric current adjustable range is big, and (10A～450A), volume is little, (be controllable silicon formula 1/6) in light weight, efficient height (raising the efficiency 20% than controllable silicon formula) is easy to carry, and protection against electric shock equipment is arranged, handling safety, advantage such as easy to use.The technology of the present invention be study in the world, promote the 4th generation Arc Welding Power.It not only belongs to the down-hole, mine and is badly in need of product, and along with the reduction of components and parts price, will promote the use of whole welding profession as great energy-conservation, efficient, high-quality arc-welding motor of new generation.

Claims (10)

1, a kind of mining transistor type high direct voltage inversion high-frequency impulse electric welding machine is by input circuit, auxiliary inverse power supply, striking high frequency electric source, high-power inverter, compositions such as welding output loop.It is characterized in that having the high-speed high-power drive circuit; ratio-voltage produces circuit; the overcurrent and overheating protection circuit; dead band levelling in the main control circuit; the frequency levelling, soft starting circuit, weldingvoltage, current control circuit; protection against electric shock and unloaded economize on electricity control circuit, high-frequency arc strike and accessory circuit thereof and employing new heat pipe heat abstractor etc.

2, according to the described electric welding machine of claim 1, it is characterized in that by IC ₃, IC ₄, BG ₉～BG ₁₈, D ₂₈～D ₂₉Deng the high-speed high-power drive circuit of forming.

3,, it is characterized in that by B in the auxiliary inverse power supply (B) according to the described electric welding machine of claim 1 ₃, D _19～20, D _22～23, L ₅, L ₇, C ₁₅, C ₁₇And B in the induced voltage circuit ₆, D ₃₄～D ₃₇, L _11～12, C ₂₈Produce circuit Deng the ratio-voltage of forming.

4, according to the described electric welding machine of claim 1, it is characterized in that by IC ₆, D ₄₅, BG ₃₂, BG ₃₃, R ₇₃Deng the high speed current foldback circuit of forming, and by IC ₅, D ₄₃, D ₄₄Deng the overheating protection circuit of forming.

5, according to the described electric welding machine of claim 1, it is characterized in that by BG ₇, R ₂₈～R ₃₁, W ₃, IC ₂The frequency levelling circuit of forming is by R ₃₂, R ₃₃, BG ₈, IC ₂, R ₃₈, D _26～27Deng the dead band control circuit of forming, and by R ₆₉, BG ₄₃, D ₂₇, C ₂₀, IC ₂Deng the soft starting circuit of forming.

6, according to the described electric welding machine of claim 1, it is characterized in that by B ₉, D ₅₁, D ₅₂, R ₇₄～R ₈₃, W ₆, IC ₂The current control circuit of forming and by D ₅₃, R ₁₁₆, R ₃₄, C ₅₀, W ₄, IC ₂Deng the voltage control circuit of forming.

7, according to the described electric welding machine of claim 1, it is characterized in that by B ₇, C ₃₃, C ₃₄, QL ₂, K ₃, D ₄₁, D ₄₂, BG ₁₉, R ₆₆～R ₆₈, R ₁₁₇～R ₁₁₉, IC ₂, C ₃₆Deng zero load economize on electricity and the electrocution-proof protection control circuit formed.

8, according to the described electric welding machine of claim 1, it is characterized in that by IC ₇, BG ₃₇～BG ₄₂, B ₈High-frequency arc ignition circuit Deng the circuit composition.

9, according to the described electric welding machine of claim 1, it is characterized in that by D ₂₄, D ₂₅, L ₈, L ₉, C _18～19And B ₅, D ₃₈, D ₃₉, D ₄₀, C ₃₂, L ₁₃The striking variable power supply of forming is by R ₈₄, D ₄₆, C ₄₁, BG ₃₄, R ₈₇The peak value type sample circuit of forming, R ₈₈, C ₄₀, C ₄₃, W ₇, IC ₇The Power Limitation circuit of forming and by R ₈₉～R ₉₂, R ₈₆, R ₈₅, R ₉₇, BG ₃₅, BG ₃₆, IC ₇The striking frequency levelling circuit of forming.

10,, it is characterized in that adopting the new heat pipe radiating mode to reach by B according to the described electric welding machine of claim 1 ₅, QL ₁, C ₃₀, the forced air cooling heat abstractor formed of fan D.

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