CN2333473Y

CN2333473Y - Controller for inverter argon arc welding machine

Info

Publication number: CN2333473Y
Application number: CN 98234660
Authority: CN
Inventors: 刘伦彦; 温清松; 温自力
Original assignee: CHANGSHENG WELDING EQUIPMENT PLANT DONGSHAN DISTRICT GUANGDONG CITY
Current assignee: CHANGSHENG WELDING EQUIPMENT PLANT DONGSHAN DISTRICT GUANGDONG CITY
Priority date: 1998-07-15
Filing date: 1998-07-15
Publication date: 1999-08-18
Anticipated expiration: 2008-07-15

Abstract

The utility model provides a controller for an inverted argon arc welder, which is composed of an argon gas control circuit, an arc guiding control circuit, a soft start circuit, a current sampling and shaping circuit, a comparison circuit, an overcurrent protection circuit and a pulse output circuit. The utility model is characterized in that an impulse width control circuit which is composed of a chip U3 and periphery elements thereof such as a resistor, a capacitance and a diode, is connected between the comparison circuit and the pulse output circuit. Because the utility model adopts an inverted power supply as a welding power supply, the electric arc of the welder has the advantages of stable combustion, concentration and good straightness; thereby, the inverted argon arc welder can be used for fine welding and has the good welding performance. The utility model has the characteristics of small size, light weight, convenient move, etc.

Description

Inversion argon arc welding machine control device

The utility model relates to the control device of argon arc welding machine, particularly a kind of inversion argon arc welding machine control device.

Common argon arc welding machine adopts silicon controlled rectification power source more, and its welding arc is thick, and the arc that looses easily, and machine volume is big, and inconvenience goes out to carry and heavy, and troublesome poeration does not reach desirable effect.

The purpose of this utility model is to overcome above-mentioned deficiency, provides a kind of arc burning stable, and electric arc is concentrated, and straightness is good, can carry out the precision welding, welding performance is good, and volume is little, in light weight, conveniently moving, the inversion argon arc welding machine control device of reasonable price.

The purpose of this utility model is achieved by the following scheme: be made of arc welding gun switch signal, argon gas control circuit, arc ignition control circuit, soft starting circuit, electric current given circuit, current sampling shaping circuit, comparison circuit, current foldback circuit, impulse output circuit etc.Also being connected to integrated chip U3 (SG3525AN) between comparison circuit and impulse output circuit is core, and the pulse width control circuit formed of peripheral cell resistance R 16, R17, R19, R20, R21, R67, capacitor C 4, C31, C6, C7, C8, Zener diode D6.Connect positive 15 volts of power supplys with 5 pin behind the 3 pin connecting resistance R17 of its chips U3; 1 pin and 12 pin ground connection; 8 foot meridian capacitor C7; resistance R 1 connects soft starting circuit; as the soft start control end; 9 pin one tunnel connect the control signal end; another road connects comparison circuit through D2; the 5th; 6; 7 pin are through resistance R 19; R20 and capacitor C 6 produce and start oscillator signal; its frequency is 25 kilo hertzs; 10 pin of U3 are through voltage-stabiliser tube D6; diode D8 takes over the stream holding circuit; the 11 pin output control pulses of U3 are connected to impulse output circuit through resistance R 18; the pulse duty factor maximum has only 50%; pulse signal is via transformer T1 and triode VT6; VT7 and capacitor C 22; resistance R 37; diode D21; the impulse output circuit that D22 forms, and be coupled to the grid of major loop FET through the secondary of transformer T1 and interface J3.

The utility model compared with the prior art, owing to adopted inverter as the source of welding current, be direct current with AC rectification earlier, utilize the conducting of FET (MOSFET) and alternating current that turn-off characteristic with dc inverter is 25 kilo hertzs again to be added on the high frequency transformer, this transformer-secondary voltage is added on the welding gun after the rectification again.It is stable to make the utility model not only have an arc burning, and electric arc is concentrated, and straightness is good, can carry out precision and weld, and welding performance is good, and it is little, in light weight to have a volume, advantages such as conveniently moving.

Below in conjunction with accompanying drawing the utility model is illustrated.

Fig. 1 is the major loop electrical schematic diagram;

Fig. 2 is the control loop block diagram;

Fig. 3 is control principle figure;

Fig. 4 is the accessory circuit schematic diagram.

As shown in Figure 1, major loop comprises that rectification circuit, filter circuit, FET inversion, transformer step-down, secondary rectifying and wave-filtering and striking pulse coupling circuit etc. partly form.Its operation principle is: adopt single-phase 220 volts of AC powers, wherein resistance R 1 is the current-limiting resistance for preventing that switching current from impacting, and with resistance R 1 excision, R2, R3 were the discharge resistances of capacitor C 1 to relay contact J1 in back 2 seconds of combined floodgate, electric charge with C1 when welding machine has a power failure bleeds off, with plan safety.When control impuls arrives, FET Q1, Q2, Q3, Q4 conducting simultaneously, the high frequency transformer energising, the transformer secondary output winding produces electric current simultaneously, (fast recovery diode D12, D13 conducting), when control impuls disappears moment, the magnetic energy that transformer itself stores is converted into electric current and charges to capacitor C 1 by diode D5, D6, and transformer flux resets to reset condition.Inductance L 1 is used for level and smooth secondary current, and diode D11, D1, D13 are as the afterflow passage between the pulse off period.Transformer T2 is coupled to the welding gun loop with the high-frequency arc strike pulse, realizes striking.Capacitor C 7, C8 and resistance R 16 make striking pulse bypass enter major loop to prevent high-voltage pulse.Capacitor C 3, C4, diode D7, D8, resistance R 10, R11 are the over-voltage protection elements of FET, capacitor C 5, C6, resistance R 12, R13, R14, R15 are the over-voltage protection elements of fast recovery diode.

As Fig. 2, shown in Figure 3, the control circuit of welding machine is a core with integrated chip U3 (SG3525AN), and wherein 3 pin of U3 connect positive 15 volts of power supplys with 5 pin after connecting resistance R 17,1 pin and 12 pin ground connection, 8 foot meridian capacitor C7, resistance R 1 connects soft starting circuit, as the soft start control end.9 pin of U3 connect control signal, and 5,6,7 pin produce oscillator signal through resistance R 19, R20 and capacitor C 6, and its frequency is 25 kilo hertzs, and from 11 pin output control pulses, the pulse duty factor maximum has only 50%.The impulse output circuit that pulse signal is formed via elements such as transformer T1 and triode VT6, VT7 and capacitor C 22, and be coupled to the major loop fet gate through T1 time grade in transformer and interface J1.

Transformer is used in the main circuit current sampling, current signal becomes the pulse on band slope, top after shaping, deliver to 4 pin of comparator B1 through resistance R 26, R27, capacitor C 10, the given signal of electric current is delivered to 5 pin of B1 through resistance R 13, two signals relatively back produce a negative pulse, this pulse to regulate the width of control impuls, reaches the purpose of regulating electric current through 9 pin that diode D2 delivers to chip U3 (SG3525AN).

Current signal after shaping is delivered to 8 pin of comparator B1 simultaneously; (obtain and be added with 5 volts of fixing voltages on 9 pin of comparator B1 by resistance R 30 and R31 dividing potential drop; corresponding to the overcurrent protection value); in a single day current signal reaches the protection value, and comparator is upset just, triggers the protection loop action that is made of comparator B2 simultaneously; then export high level by 2 pin of B2; be added to 10 pin of chip U3 through diode D8 and voltage-stabiliser tube D6, the output of U3 no pulse, thus avoid major loop to produce overcurrent.In order to protect the unlikely cause thermal damage of crossing of main transformer, be connected to temperature relay over the ground at 8 pin of comparator B2, when temperature over-range, temperature relay is started working.Because comparator B2 output high level is added to 10 pin of chip U3, makes the output of U3 no pulse, this moment, welding machine can not work on, and must treat can work on when the transformer temperature drops to normal value, had reached the purpose of overcurrent protection.

Constitute soft starting circuit by comparator B3 and capacitor C 7, resistance R 1; 8 pin of B3 are added with fixes 6 volts of voltages (being obtained by resistance R 63 and R64 dividing potential drop); when the arc welding gun switch access failure; 9 pin of B3 are low level; this moment is by the 14 pin output low levels of B3; capacitor C 7 short circuits can't be charged, and this moment, 8 pin of U3 were 0 volt of no pulse output, and welding machine is in stopped status.When the welding machine switch connection, 15 volts of voltages are added to 9 pin of B3 through arc welding gun switch and resistance R 66, this moment, the 14 pin internal transistors of B3 ended, capacitor C 7 is by the inside constant current source charging of chip U3, the 8 pin voltages of U3 slowly rise, the output pulse width degree is progressively broadened by narrow, and main circuit current is progressively increased, and realizes soft start function.

Be illustrated in figure 4 as accessory circuit: comprise the control of control of protective gas argon gas and striking pulse; operation principle is: the arc welding gun switch signal is added to triode VT5 base stage through diode D15, resistance R 69, R60; the VT5 conducting, relay 1C adhesive, the argon gas valve is opened to welding gun argon gas is provided.Decontrol arc welding gun switch, because the discharge process of capacitor C 29, several seconds ability of VT5 time-delay is ended, and the relay 1C release of delay time is delayed time argon gas and just closed in several seconds, thereby prevents the oxidation of high temperature weld seam.Striking pulsed operation during relay 2C adhesive, 5 pin of comparator B3 are added with the bias voltage about 1 volt, its 2 pin output high level.6 pin of B3 are added with 6 volts of bias voltages, and its 1 pin is output as low level, and this moment, relay 2C can not adhesive.When welding gun was connected, 15 volts of voltages made 1 pin of B3 export high level, triode VT4 conducting, relay 2C adhesive generation striking pulse by 7 pin that D14, R5 are added to B3.After the starting the arc, main circuit current is through producing signal to sensor, is added to 4 pin of B3 by D10, R46, makes the 2 pin output low levels of B3, and relay 2C discharges, and the striking pulse stops, and changes normal welding over to.

Claims

1, a kind of inversion argon arc welding machine control device; constitute by arc welding gun switch signal, argon gas control circuit, arc ignition control circuit, soft starting circuit, electric current given circuit, current sampling shaping circuit, comparison circuit, current foldback circuit, impulse output circuit etc.; it is characterized in that: also being connected to integrated chip U3 (SG3525AN) between comparison circuit and impulse output circuit is core, and the pulse width control circuit formed of peripheral cell resistance R 16, R17, R19, R20, R21, R67, capacitor C 4, C31, C6, C7, C8, Zener diode D6.

2; control device according to claim 1; it is characterized in that: connect positive 15 volts of power supplys with 5 pin behind the 3 pin connecting resistance R17 of said chip U3; 1 pin and 12 pin ground connection; 8 foot meridian capacitor C7; resistance R 1 connects soft starting circuit; as the soft start control end; 9 pin one tunnel connect the control signal end; another road connects comparison circuit through D2; the 5th; 6; 7 pin are through resistance R 19; R20 and capacitor C 6 produce and start oscillator signal; its frequency is 25 kilo hertzs; 10 pin of U3 are through voltage-stabiliser tube D6; diode D8 connects current foldback circuit; the 11 pin output control pulses of U3 are connected to impulse output circuit through resistance R 18; the pulse duty factor maximum has only 50%; pulse signal is through transformer T1 and triode VT6; VT7 and capacitor C 22; resistance R 37; diode D21; the impulse output circuit that D22 forms, and be coupled to the major loop fet gate through pulse transformer secondary output and interface J3.