CN205496751U - Structure that accords with IGBT contravariant manual metal -arc welding machine of EMC authentication requirement - Google Patents

Abstract

The utility model relates to a structure that accords with IGBT contravariant manual metal -arc welding machine of EMC authentication requirement and circuit design. Welding machine circuit board design is two, and the welding of little control panel is on big control panel, whole control circuit mainly comprises nine functional circuits such as input filter circuit, contravariant main circuit, output filter circuit, switching power supply circuit, IGBT's drive circuit, current detection and rectification transfer circuit, hot protection detection and control circuit, the preset circuit of electric current, output characteristic control circuit. Circuit on the little control panel mainly is output characteristic control circuit, and its core comprises 3846 PWM pulse width modulation chips and peripheral device. The utility model discloses a EMC electromagnetic compatibility procedure, as follows mainly: 1 )The filtering of input two -stage, 2) output filtering, 3 )IGBT switch and output Rectifier are anti -interference, 4 )In the aspect of structural design, electromagnetic shield measure in addition, the effects such as keeping apart strong electromagnetic interference, restriction electromagnetic radiation of can playing.

Description

A kind of structure of the IGBT inversion manual arc welder meeting EMC authentication requesting

Technical field

This utility model relates to the hand arc welding machine of a kind of single tube IGBT inversion meeting EMC authentication requesting, belongs to inverse Become welding machine technical field.

Technical background

At present, the competition in Inverter Hand arc-welding machine product market is the fiercest, is not only embodied in the advance of technology and excellent In gesture, the aspect such as function and design of also depending greatly on welding machine.

On domestic and international market, small-sized metal-oxide-semiconductor, the rated current of IGBT pipe Inverter Hand arc-welding machine are generally born at 80 ~ 200A( Carry water holdup 100 ~ 15%) level.But this type of welding machine product most all cannot be detected and certification by EMC performance, a lot Product the most also cannot pass through security credential, only meets the welding requirements of manual metal-arc welding.Its products export can be by certain Limit.Cannot export to require the country that welding machine meets EMC performance and authentication requesting, such as the U.S., Australia, add and take Greatly, European Union etc..

For meeting the welding machine of the certification such as EMC and safety, owing to its performance is more preferable, thus its selling market and application Scope can be wider.Production marketing can be more added with the market competitiveness.But, this type of welding machine, different circuit, circuit board and complete machine knots Structure designs, and control principle is different with mode, and circuit board is different with the layout of complete machine, the safety of its product, EMC electromagnetic compatibility Property, the operation of production and processing technology etc. also can be entirely different.These all can affect performance and the cost of product.Therefore, how On the premise of low cost, exploitation performance meets the welding machine of above-mentioned authentication requesting certain technical difficulty. and this is also this reality The problem solved with novel needs.

Utility model content

The purpose of this utility model is to provide the structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, There is the function of manual arc soldering method, and meet Product Safety, the detection of EMC performance and authentication requesting, welder circuit plate It is designed as two pieces.Little panel is welded on big panel, and whole control circuit is mainly by input filter circuit, the main electricity of inversion Road, output filter circuit, switching power circuit, the drive circuit of IGBT, current detecting and rectification transformating circuit, Thermal protection detection With nine functional circuit compositions such as control circuit, given value of current circuit, output characteristics control circuit, the main circuit on little panel If output characteristics control circuit, its core is made up of 3846 pwm pulse width modulated chips and peripheral components thereof, this practicality Novel EMC electromagnetic compatibility procedure, mainly has: 1) input two stage filter；2) output filtering；3) IGBT switch and output rectification Anti-interference；4) electromagnetic shielding etc.；Above-mentioned measure is to ensure that welding machine product of the present invention can be detected by EMC internal authority mechanism performance With the important prerequisite of certification, additionally, this utility model welding machine that different current classes and cyclic duration factor are required, can pass through to adjust Amount of parts a small amount of on whole circuit board and specifications parameter, form difference output rated current and the product of cyclic duration factor, Such as 200A/28V(25%, cyclic duration factor, lower with), 180A/27.2V(35%), 160A/26.4V(45%), 140A/25.6V (50%), 120A/24.8V(60%), 100A/24V(80%), 80A/23.2V(100%) etc.；Every kind of welding machine can realize relatively optimizing Cost control, this just improves product competitiveness in the market.This utility model welding machine, owing to having good EMC Electro Magnetic Compatibility And safety Design, solve this type of welding machine a lot of and cannot pass through the problem of EMC certification, thus welding machine has more preferable market fit Property.

The most by the following technical solutions:

A kind of structure of the IGBT inversion manual arc welder meeting EMC authentication requesting, it is characterised in that: include housing portion, Front-facing portion, rear board part and panel part, it is characterised in that: described panel part includes panel and control Platelet, is controlled platelet and is directly welded on panel by plug-in unit, is no need for using connecting line to carry out even between circuit board Connect；The main circuit input filter circuit to be included of panel part, inverter main circuit, output filter circuit, switching power circuit, The drive circuit of IGBT, current detecting and rectification transformating circuit, Thermal protection detection and control circuit, given value of current circuit, output These nine functional circuits of characteristic controling circuit, complete input filter, output filtering, anti-interference, the generation of power supply, PWM arteries and veins Rush width adjusting, the driving of IGBT pipe controls, the negative feedback control of the inverter circuit output parameter (electric current) of manual metal-arc welding welding method Work.The circuit of panel part and the electric current regulator potentiometer on welding machine front panel, rear board, display lamp, on and off switch, wind Fan and carry out mutual circuit connection by some pilots.

It is disposed with IGBT and fin, CBB475K/400V electric capacity, the big electricity of 470uF/400V on described panel Solve electric capacity, PCB, 2C3 electric capacity, 2MT1 inductance, 2MT2 inductance, driving transformer, current transformer, rectifier bridge and dissipate Hot device, switching mode power supply transformer, 24V relay, integrated regulator 7815, metal-oxide-semiconductor IRFZ24N, metal-oxide-semiconductor IRF9Z24N, output Filter reactor, fast recovery diode or rectifier tube and radiator, inversion main transformer；Panel is provided with control platelet Interface MK1, control platelet be to be directly welded on panel by plug-in unit.

On described little control circuit plate, layout has output characteristics control circuit, and output characteristics control circuit is by U2 PWM arteries and veins Rush width modulated chip, tetra-operational amplifiers of U1 and a lot of resistance of these device periphery, electric capacity and diode composition.

Described control circuit is provided with input two stage filter circuit, output filter circuit, IGBT switch and output rectification Anti-jamming circuit.

Described front-facing portion is provided with: two groups of outputs snap joint holder assembly, working power display lamp, Thermal protection shapes State display lamp, electric current output regulator potentiometer.

It is provided with on described rear board: on and off switch, band plug power supply line, cooling blower, cold wind is from welding machine machine The air inlet at case rear portion is carried out；Some heater members on circuit board or parts can be made to have good cooling effect.

The board design of this utility model welding machine is two pieces.One piece of big panel, one piece of little panel.The latter is by even Fitting is welded on the former.Whole control circuit is mainly by input filter circuit, inverter main circuit, output filter circuit, switch Power circuit, the drive circuit of IGBT, current detecting and rectification transformating circuit, Thermal protection detection and control circuit, given value of current Nine functional circuit compositions such as circuit, output characteristics control circuit.Circuit on little panel, mainly output characteristics control electricity Road.Its core is 3846 pwm pulse width modulated chips and the circuit of peripheral components composition thereof.From the point of view of the function of its circuit, Mainly complete input filter, output filtering, anti-interference, the generation of power supply, pwm pulse width adjusting, IGBT pipe drive Control, the work such as the negative feedback control of the inverter circuit output parameter (electric current) of manual metal-arc welding welding method.Final in control circuit Effect under, it is achieved manual arc welding, meet the detection of EMC performance and the requirement such as certification.

About the EMC electromagnetic Compatibility Design measure of this utility model welding machine, mainly have the following aspects: 1) input two Level filtering measures.On the one hand, mainly the interference signal from electrical network is filtered, reduces or reduce interference signal to this The adverse effect of bright welding machine control circuit work.On the other hand, the interference signal that welder circuit produces, by this filter circuit Time, also can be controlled, can be reduced or reduce the interference signal adverse effect to power supply grid from welding machine；2) output filtering Measure.It is made up of output current filtering inductance L, filter capacitor C45 and C46.Current fluctuation can be suppressed, reduce in current waveform Burr jump signal；3) IGBT switch and output rectification interference protection measure.Mainly by IGBT device and fast quick-recovery two The two ends parallel resistance of pole pipe and electric capacity, the spike interference signal that composition anti-jamming circuit reduces or controls in inversion conversion； 4) at structure design aspect, the also measure of electromagnetic shielding.Panel stands and is arranged on welding machine base plate.Be equivalent to by shell, The metal shell of base plate and rear board, front panel composition surrounds.Isolation strong electromagnetic, limit electromagnetic radiation etc. can be played make With.

Above-mentioned measure is to ensure that the welding machine product made based on circuit of the present invention can pass through EMC internal authority mechanism performance Detection and the important prerequisite of certification.It is to be noted that there is not above-mentioned filter circuit just can solve EMC problem.Also relate to And design and the select permeability such as components and parts and the parameter of parts, material, position in filter circuit.Such as, filter inductance Core material and the selection of umber of turn；The selection of capacitance parameter；The position etc. of filter arrangement, all can examine EMC performance Survey and produce impact.

This utility model welding machine requiring different current classes and cyclic duration factor, can be a small amount of by adjusting on circuit board Amount of parts and specifications parameter, form difference output rated current and the product of cyclic duration factor, make product seriation.Example As, change the number of big electrochemical capacitor；Change rectifier bridge parameter；Change current class and the heat sink size of IGBT device；Change Become model and the parameter of fast recovery diode；Change inversion main transformer and the specification of output filter reactor and parameter etc., Can easily form the series of products of different size.Such as 200A/28V(25%, cyclic duration factor, lower with), 180A/27.2V (35%), 160A/26.4V(45%), 140A/25.6V(50%), 120A/24.8V(60%), 100A/24V(80%), 80A/23.2V (100%) multiple current class and the product of specifications and models.Rated current is the least, then rated duty cycle is the highest.Certainly, These changes, it is therefore an objective to make the cost of manufacture of product match with the specifications parameter of corresponding machine and performance indications.So, every kind The welding machine of specifications and models could realize optimized cost control.This just improves the market competitiveness of institute's development.

This utility model welding machine, owing to having good EMC Electro Magnetic Compatibility and safety Design, solve a lot of this type of Welding machine cannot pass through the problem of EMC certification, thus welding machine has more preferable market adaptability.Its good circuit and structure design thereof Also it is advantage place of the present utility model, is also to meet efficiently and low-cost production, high reliability, the weight of manufacturing technology advance Ensure.

Accompanying drawing explanation

Accompanying drawing 1 is this utility model explosive view；

Accompanying drawing 2 is the circuit theory diagrams of this utility model welding machine；

Accompanying drawing 3 is the PCB components' placement figure of this utility model welding machine big control circuit plate；

Accompanying drawing 4 is the PCB components' placement figure of this utility model welding machine little control circuit plate；

Accompanying drawing 5 is the schematic diagram of this utility model panel；

In accompanying drawing, the title of each parts is as follows: 1, handle screw；2, handle；3, shell screw；4, shell；5, panel； 6, power line；7, wire fixer；8, on and off switch；9, blower fan protective cover；10, base plate；11, cooling fan；12, working power instruction Lamp；13, guard mode display lamp；14, potentiometer；15, black snap joint holder assembly；16, red snap joint holder assembly； 17, IGBT fin；18, CBB475K/400V electric capacity；19, IGBT fin；20, electrochemical capacitor；21, PCB；22、 275VAC electric capacity；23, input inductance；24 input inductance；25, driving transformer；26, current transformer；27, rectifier bridge；28, whole Stream bridge fin；29, switching mode power supply transformer；30, relay；31, three terminal regulator；32, metal-oxide-semiconductor IRFZ24N；33, metal-oxide-semiconductor IRF9Z24N；34, platelet is controlled；35, output filter reactor；36, rectifier tube fin；37, rectifier tube；38, inversion main transformer Depressor；39, IGBT pipe.

Detailed description of the invention

As Figure 1-4, the structure key component bag of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting Include:

1) housing portion；Including shell 4, handle 2, handle screw 1 and shell screw 3 etc..

2) in rear board part install parts mainly have: on and off switch 8, power supply line and plug 6, wire fixer 7, The parts such as blower fan protective cover 9, cooling fan 11；Power line and plug 6 are connected to power supply grid, and on and off switch 8 controls welding machine electricity The on-off in source, cooling fan 11 is positioned at the rear portion of welding machine, and the cold wind air inlet from welding machine case rear board rear portion is carried out.Can make Some heater members of left side circuit part or parts, such as IGBT and Heat Sink A heat sink, fast recovery diode and heat radiation The parts such as device are preferably cooled down.Such air channel and type of cooling design, what beneficially guarantee welder circuit worked can By property, it also it is one of this utility model welding machine major reason of realizing larger current and high capacity water holdup.

3) front-facing portion, the parts installed on welding machine front panel mainly have: black output snap joint holder assembly 15, red output snap joint holder assembly 16, working power display lamp 12 and Thermal protection status indicator lamp 13, manual welding electric current are defeated Go out regulator potentiometer 1) etc. part.Two groups of output snap joint holder assemblies 15,16 connect electric welding when manual electric arc welding respectively Pincers cable and workpiece clamp cable；Working power display lamp 12 indicates power on.It is overheated that Thermal protection status indicator lamp 13 then indicates Whether state occurs.When internal components temperature is too high, when exceeding operating temperature, under the effect of control circuit, on the one hand can make This display lamp is lighted；On the other hand, welding machine can be made to stop welding or output.In the case of welding machine does not exports, the cooling of blower fan Effect can make the temperature of device reduce.When being reduced to recovery action temperature, welding machine superheating phenomenon eliminates.Overheating indicator lamp puts out Go out.Meanwhile, welding machine can weld again.Certainly, according to the needs of production, front panel 18 also can arrange ammeter, voltage The parts such as table, with function or the performance of extended products.

4) panel part, including a lot of parts on panel 5 and this panel, such as, IGBT and fin thereof With fin 02, CBB475K/400V electric capacity, the big electrochemical capacitor of 470uF/400V, PCB 21,2C3 electric capacity, 2MT1 electricity Sense, 2MT2 inductance, driving transformer, current transformer or electric current loop 26, rectifier bridge 27 and radiator 28 thereof, Switching Power Supply transformation Device 29,24V relay 30, integrated regulator 7815, metal-oxide-semiconductor IRFZ24N and IRF9Z24N, control platelet 34, output filtered electrical Anti-device 35, fast recovery diode or rectifier tube 37 and the part such as radiator 36, inversion main transformer 38 thereof.

On panel 5 and control platelet 34, the most a lot of electronic devices and components, such as resistance, electric capacity etc., circuit board controls Part and the components and parts in welding machine front and back panels, such as electric current regulator potentiometer 14, fan 11, display lamp 12 and 13, on and off switch 8 etc., carry out mutual circuit by some pilots and connect, between each circuit board, between device or parts, according to this The circuit theory diagrams relation (see accompanying drawing 2) of utility model welding machine links together, and can meet the circuit of manual welding method function Output characteristics controls.

As shown in Figure 2, panel 5 is provided with the interface MK1 of control platelet 34；Two blocks of control circuit plates be exactly according to Corresponding interface identifier and circuit theory diagrams link together, and controlling platelet 34 is to be directly welded at large circuit board by plug-in unit Or on panel 5, be no need between such circuit board using connecting line to be attached.

Accompanying drawing 2 is the circuit theory diagrams of this utility model welding machine, and whole control circuit is mainly by input filter circuit, inversion Main circuit, output filter circuit, switching power circuit, the drive circuit of IGBT, current detecting and rectification transformating circuit, Thermal protection Detection and nine functional circuit compositions such as control circuit, given value of current circuit, output characteristics control circuit.From the function of its circuit From the point of view of, mainly complete input filter, output filtering, anti-interference, the generation of power supply, pwm pulse width adjusting, IGBT pipe The work such as driving controls, the negative feedback control of the inverter circuit output parameter (electric current) of manual metal-arc welding welding method.Finally controlling Under the effect of circuit, it is achieved manual arc welds, meets the requirements such as the detection of EMC performance and certification.Below to relevant function electricity Road carries out some and illustrates:

Seeing accompanying drawing 2, input filter circuit is made up of filter inductance 2MT1 and 2MT2, filter capacitor 2C1 ~ 2C5, resistance 2R1.

See accompanying drawing 2, inverter main circuit by and off switch S1, input filter circuit, BD1 rectifier bridge, PTC1 critesistor, JR1 relay, the big electrochemical capacitor of C12, C13, C60, C61, G1 ~ G4 IGBT pipe, T1 inversion main transformer, D8 ~ D11 and D23 ~ The composition bridge inverter main circuit such as D24 fast recovery diode, output filter circuit.By OUT(+) positive polarity and OUT(-) negative pole Property outfan output welding current and voltage.

See accompanying drawing 2, output filter circuit by exporting current filtering inductance L, filter capacitor C45 and C46 forms.

See accompanying drawing 2, switch power supply route T4 switching mode power supply transformer, M1 metal-oxide-semiconductor, IC2 (3843) pwm pulse width Manipulator, D15 ~ 16, D12 and D14 fast diode, IC4(7915) and IC5(7815) integrated regulator, and around them Resistance, electric capacity, the device such as stabilivolt ZD3 and ZD4 composition.

Seeing accompanying drawing 2, the drive circuit of IGBT is by T3 driving transformer, Q6 ~ Q9 metal-oxide-semiconductor field effect transistor, quick two poles of D4 ~ D7 Manage, and the resistance of they peripheries, electric capacity etc. form.

See that accompanying drawing 2, current detecting and rectification transformating circuit are by current detecting ring or T2 current transformer, D19 ~ D22, computing Amplifier IC1C, resistance R45 and R50 ~ R52 etc. form.

Seeing accompanying drawing 2, Thermal protection detection and control circuit are by critesistor RT2D, operational amplifier IC1A and IC1B and outer Device, audion Q5, optocoupler IC8, LEDY, CN2 and the welding machine faces being attached thereto thereof such as a lot of resistance, electric capacity and the diode that enclose Plates overheated indication LED lamp (yellow) etc. form.LEDY(yellow) for welding overtemperature protection indication LED lamp on circuit boards.Peace During dress critesistor RT2D, its temperature detection face is allowed to be close to the radiator of IGBT.

See accompanying drawing 2, output electric current regulator potentiometer that given value of current circuit is connected, electricity by operational amplifier IC1D with CN1 The compositions such as stream correcting potential device RP1 and RP2, resistance R46 ~ R49, electric capacity C66 ~ C67.

Seeing accompanying drawing 2, output characteristics control circuit is by U2 pwm pulse width modulated chip (3846), tetra-operation amplifiers of U1 Device, and the device such as a lot of resistance, electric capacity and the diode of these device periphery composition.

The operation principle of this utility model welding machine each part mentioned above functional circuit is summarized as follows: as shown in Figure 2.L Yu N end It is connected to the power supplies such as 220V/50Hz.After on and off switch S1 connects electric network source, welding machine is energized.Power supply on front panel refers to Show that lamp is lighted.The alternating current come from electrical network, first passes through two-stage input filter circuit, then becomes pulsation after BD1 rectifier bridge rectification Unidirectional current.Output after rectification, first passes through PTC1 critesistor, afterwards, to C12, C13, C60, C61 electrochemical capacitor (470 F/ 400V) being charged, voltage gradually rises, and eventually becomes relatively stable+310V unidirectional current, by output between A, B to rear class electricity Road.

JR1 relay can be connected on and off switch S1, action after the certain time-delay time, its contact closure or short circuit PTC1 heat Quick resistance.The time delay of JR1 relay is controlled by circuit and realizes.The charging of the big electrochemical capacitor of C12, C13, C60, C61, First pass through PTC1 critesistor, the most again short circuit PTC1 critesistor.Such control circuit is referred to as the buffer circuit that powers on.

C12, C13, C60, C61 are big, and electrochemical capacitor plays a part filtering.The on the one hand supply of+310V unidirectional current is by G1 ~ G4 The full-bridge of the composition such as IGBT pipe, T1 inversion main transformer and D8 ~ D11, D23 ~ D24 fast recovery diode, L output filter reactance Inverter main circuit.Its function is mainly: high voltage direct current is converted to intermediate frequency (tens KHz) alternating current.T1 contravariant transformer realizes Voltage step-down and the conversion of High-current output.D8 ~ D11, D23 ~ D24 fast recovery diode then export contravariant transformer Medium frequency alternating current is transformed to unidirectional current.Current waveform after converting due to it is pulsation, unstable, is unfavorable for welding process Stable, therefore, use current filter reactor L to be filtered.So, the current waveform of output will become stable.Be conducive to Obtain high-quality weld seam.

On the other hand ,+310V unidirectional current supplies by T4 switching mode power supply transformer, M1 metal-oxide-semiconductor, IC2 (3843) pwm pulse Width modulator, D15 ~ 16, D12, D14 fast diode, IC4(7915), IC5(7815) integrated regulator, and they week The switching power circuit of the device compositions such as the resistance that encloses, electric capacity, stabilivolt ZD3 and ZD4, produces+5V ,+15V ,+24V ,-15V electricity Source voltage, supplies the live line work such as corresponding control circuit.For switching power circuit part, owing to M1 metal-oxide-semiconductor switchs with T4 The armature winding of mains transformer, and the group such as ZD4 stabilivolt, D15 ~ D16 diode, a lot of resistance and the electric capacity around them The circuit become, is belonging to+310V high tension loop.For guaranteeing the safety of control circuit, in fig 2, have employed IC3 (817) Photoelectrical coupler is isolated.It is IC2 that Switching Power Supply PWM controls the kernel control chip of platelet, i.e. 3843 pwm pulse width Actuator.The resistance of its periphery, electric capacity can set the relevant parameter of its work.As to how determine, need to check UC3843(or TL3843) data used in connection with or explanation.It is not repeated herein.In a word, the pulse of IC2 output is driving of certain operating frequency Moving pulse, can make the M1 metal-oxide-semiconductor in accompanying drawing 2 be in break-make duty.In 4 voltage follower circuit parts of T4, obtain respectively Obtain+5V ,+15V ,+24V ,-15V supply voltage.Supply different devices and circuit uses.Such as ,+24V is supplied by CN3 plug To fan work；+ 15V and-15V power supply voltage supplying opamp control circuit etc..Work about this part of Switching Power Supply Making principle, above section has only been by simple illustration.If needing to understand the working condition that this circuit part is detailed, relate to A lot of knowledge to Switching Power Supply.Reader can inquire about relevant on-off circuit books or data is made further to understand.The most not Describe in detail again.

From circuit and the principle of Switching Power Supply part, this utility model does not use general control transformator and phase The voltage conversion circuit closed produces above-mentioned 4 supply voltages.Its circuit power taking is from+the 310V in major loop.Switch transformation The volume of device and size, being significantly less weight than general control transformator, this just reduces the cost of this utility model welding machine, improves The technical value added of welding machine.

Already described above, in accompanying drawing 2, JR1 pull up time lags behind on and off switch S1 and closes the moment. I.e. JR1 relay is deferred action.After the charging voltage on the big electrochemical capacitor of C12, C13, C60, C61 is stable, this relay Device just action, its contact closure PTC1 critesistor, when making the normal inversion of this utility model welding machine work, big electric current is from relay The contact of device flows through.Such circuit, is referred to as the buffer circuit that powers on.Mainly prevent on and off switch S1 from connecting moment, due to There is no voltage on C12, C13, C60 electrochemical capacitor, be equivalent to short circuit, bigger surge current can be formed, burn out on and off switch S1. And the effect of the buffer circuit that powers on, it is simply that by closing a floodgate, moment seals in PTC1 critesistor, carrys out limit inrush currents.Further, The resistance of PTC1 critesistor, rises with its temperature and increases.Therefore, the buffer circuit that powers on can play preferably protects work With.

In accompanying drawing 2, T3 driving transformer, Q6 ~ Q9 metal-oxide-semiconductor field effect transistor, D4 ~ D7 fast diode, and they peripheries The driving circuit section of the composition IGBT such as resistance, electric capacity.4 IGBT, 4 roads drive, and the drive circuit form of each part is one Cause.This partial circuit, control signal A5 of input, A7 are from the A OUT of U2 pwm pulse width modulated chip (UC3846) With B OUT outfan.Owing to the signal of U2 chip output drives power little, therefore need to be amplified through power circuit of overdriving, Go to control the duty of 4 IGBT by the drive circuit of T3 driving transformer and periphery thereof again.U2 pulse width modulation (PWM) control signal that chip (UC3846) exports is two prescription wave pulse signals.Two prescription wave pulse signals have in time One regular time is poor, and specialty is also referred to as Dead Time.Be ensure IGBT two groups switch alternation important parameter it One.This time is peripheral components (R21 and R22 of RT end by UC3846 chip；The C7 of CT end) parameter arrange and determine. As to how determine, need to check the data used in connection with of UC3846 or explanation.It is not repeated herein.Need exist for explanation It is: pwm pulse bandwidth modulation signals is to determine welding machine inverter main circuit output voltage and the signal of size of current.And pwm pulse Bandwidth modulation signals is then regulated Setting signal Ug and current negative feedback signal Ufi by the electric current of welding machine and determines.

See accompanying drawing 2, by current detecting ring or T2 current transformer, finally exported by current detecting and rectification transformating circuit Current negative feedback signal Ufi.It is connected to the A24 in output characteristics control circuit.

See that accompanying drawing 2, output electric current regulator potentiometer are connected to given value of current circuit by CN1.By given value of current circuit, By the outfan of operational amplifier IC1D, i.e. A21 end obtains electric current regulation Setting signal Ug.Current correction potentiometer RP1 and RP2, the minimum and maximum electric current of recoverable welding machine output.By with the coordinating of given potentiometer, the output electric current of welding machine can be made Meet the requirement of curent change scope in nameplate.

The control process of this utility model welding machine manual electric arc welding output characteristics is summarized as follows:

The switch of welding machine rear board closes and connects after power supply extremely short time that (during this, welder circuit powers on Dash-control, have certain delays time to control), the above-mentioned each panel live line work within welding machine.Power supply instruction on front panel LED is bright, and instruction welding machine is charged.U2 pwm pulse Width Control circuit within welding machine produces the pulse that a dutycycle is bigger Signal, makes the drive circuit works of IGBT, makes two groups of IGBT be in alternating conductive state, finally makes inverter main circuit output no-load Voltage.When operator regulates the given potentiometer signal Ug of welding current on front panel, and when welding, examined by electric current Survey ring or T2 current transformer, current detecting and rectification transformating circuit can detect that the primary electricity in inverter main circuit Stream signal, i.e. current negative feedback signal Ufi.This current negative feedback signal Ufi, compares with welding current Setting signal Ug. Difference signal after Bi compare, by the output characteristics control circuit in accompanying drawing 2, carries out PI(ratio and integration) regulation control.Its The pulse width of the output control U2 PWM chip of output or dutycycle output.By the drive circuit of IGBT, control inversion master The make-and-break time of IGBT in circuit, final decision welding machine output electric current and the size of voltage, it is achieved export the accurate of current parameters Control.And to make the output characteristics of welding machine be the dropping characteristic dragged outside constant current band.Say further, as welding current Setting signal Ug Time constant, the negative feedback Ufi current signal detected along with welder circuit increases, and, after reaching given setting value, welding Given value of current Ug signal can reduce with electric current increase with the difference of Ufi current feedback control signal, after PI control, makes Pulse width or the dutycycle of welding machine output PWM chip reduce, and the output voltage of welding machine reduces.This process is namely so-called Current cut-off negative feedback control.The feedback control i.e. only just worked after electric current reaches the setting value of welding current potentiometer System.Hereafter, along with the increase that electric current is small, voltage reduces can be a lot.When welding machine output voltage drops to below 16V, along with The reduction of voltage, control circuit can make the pulse width of U2 PWM chip or dutycycle increase, make welding current according to setting Parameter increases, and ultimately forms the dropping characteristic dragged outside constant current band.When welding current Setting signal changes, Current cut-off negative feedback Setting value is different, but other control process is similar.So, between the minimum and maximum that potentiometer sets, so that it may obtain Must be without several negative characteristic curves.Such control, is also the basic demand meeting manual arc welding.About U2 PWM (3846) operation principle of this partial circuit, above section has only been by simple illustration.If needing to understand this circuit part Divide detailed working condition, relate to a lot of knowledge of 3846 chips.Reader can inquire about relevant books or data is made further Understanding.The most no longer describe in detail.

About overtemperature protection control, carry out some explanations below.In welding machine output procedure, when the radiator of IGBT occurs During superheating phenomenon, or when (being close to the radiator installation of IGBT) the critesistor RT2D inspection in Thermal protection detection and control circuit Measure the radiator of IGBT overheated time, overturn by the operational amplifier state in Thermal protection detection and control circuit, make three poles Pipe Q5 turns on, and welding overtemperature protection indication LED Y lamp on circuit boards is lighted；The overheated instruction of welding machine panel being connected with CN2 LED (yellow) is lighted.Meanwhile, the lumination of light emitting diode in IC8, its internal triode ON.The output letter of optocoupler IC8 Number, it is connected to output characteristics control circuit.By this circuit, the pulse output of U2 PWM chip can be closed, make welding machine stop defeated Go out electric current.Under the effect of cooling blower, when superheating phenomenon eliminates, control circuit just can continue to put out pwm control signal.With Time overheating indicator lamp (yellow) extinguish.Which achieves welding machine overtemperature protection.

About the EMC electromagnetic Compatibility Design measure of this utility model welding machine, mainly there is the following aspects:

1) input two stage filter measure.Seeing accompanying drawing 2, input filter circuit is by filter inductance 2MT1 and 2MT2, filter capacitor 2C1 ~ 2C5, resistance 2R1 form.Have employed the mode of two stage filter.On the one hand, mainly the interference signal from electrical network is entered Row filtering, reduces or reduces the adverse effect that welding machine control circuit of the present invention is worked by interference signal, it is ensured that welding machine reliably working. On the other hand, the interference signal that welder circuit produces, during by this filter circuit, also can be controlled, can reduce or reduce and From the interference signal adverse effect to power supply grid of welding machine.It is to be noted that be not to have above-mentioned filter circuit just can solve EMC problem of determining.Further relate to the design such as components and parts and the parameter of parts, material, position and selection in filter circuit ask Topic.Such as, the core material of filter inductance and the selection of umber of turn；The selection of capacitance parameter；The position etc. of filter arrangement, The detection of EMC performance will be produced impact.

2) output filtering measures.See accompanying drawing 2, output filter circuit by export current filtering inductance L, filter capacitor C45 and C46 forms.Current fluctuation can be suppressed, reduce the burr jump signal in current waveform.

3) IGBT switch and output rectification interference protection measure.Seeing accompanying drawing 2, in inverter main circuit work process, IGBT switchs Device, during break-make control, can produce spike interference signal.These interference signals are in parallel at IGBT device two ends Resistance and electric capacity (such as R22, C21；R25、C24；C15 ~ C16 etc.) anti-jamming circuit reduced or controlled.And it is in parallel Resistance at fast recovery diode device D8 ~ D11, D23 ~ D24 two ends and electric capacity are (such as R27, C26；R26、C25；C44 etc.) anti- Interference circuit then can reduce the spike interference signal in fast recovery diode switching process.

Additionally, at structure design aspect, the also measure of electromagnetic shielding.Panel of the present utility model (5) stands to be installed On base plate.The part such as inversion and control circuit is equivalent to by shell (4), base plate and rear board (10), the gold of front panel composition Belong to shell to surround.The isolation effect such as strong electromagnetic, limit electromagnetic radiation can be played.

Above-mentioned measure is to ensure that the welding machine product made based on circuit of the present invention can pass through EMC internal authority mechanism performance Detection and the important prerequisite of certification.

Be above each circuit part of this utility model welding machine and manual metal-arc welding method briefly controls procedure declaration.Due to This utility model has been presented for the detailed circuit schematic diagram of accompanying drawing 2, therefore, for there being circuit reading ability (or to possess relevant Electric circuit knowledge) people for, can understand completely.Circuit diagram is exactly a kind of noiseless language.But, for there is no circuit For the people of reading ability (or not possessing interlock circuit knowledge), even if that explains is the most, they are also elusive.In view of The relation of length, can only illustrate main part, herein so that reader better understood when operation principle and the process being correlated with.

Visible by described above, this utility model circuit has mentality of designing and the method for oneself uniqueness.Not only can realize Welding machine manual metal-arc welding welding method output etc. control, and, designed control circuit and the complete machine structure of welding machine, be all to make this reality Meet EMC and security credential requirement with new welder product, there is the basic reason institute of the technical advantages such as good control performance , also it is to meet product efficiently and low-cost production, high reliability, the important leverage of manufacturing process technology advance.This practicality The content of new patent application protection is that the structure protecting this welding machine designs.

Additionally, connect simple between circuit board of the present utility model, on circuit board, device is much to use automatic placement machine Completing processing with inserter, its manufacturing process and production technology are greatly simplified, reduce product weight, production and cost of transportation.

Above content be combine concrete machine structure and circuit board and control function this utility model is made detailed Explanation, it is impossible to assert that of the present utility model being embodied as is only limited to these explanations.To its of technical field described in the utility model For he technical staff, without departing from the inventive concept of the premise, it is also possible to make some other deduction and conversion, these All should be considered as belonging to the category of this utility model protection.

Claims (7)

1. the structure of the IGBT inversion manual arc welder meeting EMC authentication requesting, it is characterised in that: include housing portion, front Faceplate part, rear board part and panel part, it is characterised in that: described panel part includes panel and controls little Plate, is controlled platelet and is directly welded on panel by plug-in unit, is no need for using connecting line to be attached between circuit board； The main circuit input filter circuit to be included of panel part, inverter main circuit, output filter circuit, switching power circuit, The drive circuit of IGBT, current detecting and rectification transformating circuit, Thermal protection detection and control circuit, given value of current circuit, output These nine functional circuits of characteristic controling circuit, complete input filter, output filtering, anti-interference, the generation of power supply, PWM arteries and veins Rush width adjusting, IGBT pipe drives control, the negative feedback control work of the inverter circuit output parameter of manual metal-arc welding welding.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: it is characterized in that: the circuit of described panel part and the electric current regulator potentiometer on welding machine front panel, rear board, refer to Show that lamp, on and off switch, fan carry out mutual circuit by some pilots and connect.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: it is disposed with IGBT and fin thereof, CBB475K/400V electric capacity, 470uF/400V big electrolysis electricity on described panel Appearance, PCB, 2C3 electric capacity, 2MT1 inductance, 2MT2 inductance, driving transformer, current transformer, rectifier bridge and heat radiation thereof Device, switching mode power supply transformer, 24V relay, integrated regulator 7815, metal-oxide-semiconductor IRFZ24N, metal-oxide-semiconductor IRF9Z24N, output filter Wave reactor, fast recovery diode or rectifier tube and radiator, inversion main transformer；Panel is provided with and controls platelet Interface MK1, controlling platelet is to be directly welded on panel by plug-in unit.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: on described control platelet, layout has output characteristics control circuit, and output characteristics control circuit is adjusted by U2 pwm pulse width Coremaking sheet, tetra-operational amplifiers of U1 and the resistance of these device periphery, electric capacity and diode composition.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: it is anti-interference that described control circuit is provided with input two stage filter circuit, output filter circuit, IGBT switch and output rectification Circuit.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: described front-facing portion is provided with: two groups of output snap joint holder assemblies, working power display lamp, Thermal protection states refer to Show that lamp, electric current export regulator potentiometer.

The structure of a kind of IGBT inversion manual arc welder meeting EMC authentication requesting, its feature exists In: it is provided with on described rear board: on and off switch, band plug power supply line, cooling blower, cold wind is from welding machine case rear portion Air inlet carry out；Some heater members on circuit board can be made to have good cooling effect.