CN212761661U

CN212761661U - Gas-free protective electric arc welding machine with microprocessor controlling voltage regulation and wire regulation

Info

Publication number: CN212761661U
Application number: CN202020999215.XU
Authority: CN
Inventors: 陈权; 蔡庆乐; 魏继昆; 陈法庆; 朱宣辉; 朱宣东
Original assignee: Zhejiang Kende Mechanical & Electrical Co ltd
Current assignee: Zhejiang Kende Mechanical & Electrical Co ltd
Priority date: 2020-06-03
Filing date: 2020-06-03
Publication date: 2021-03-23
Anticipated expiration: 2030-06-03

Abstract

The utility model relates to a gas-protection-free arc semi-automatic welding machine for controlling voltage regulation and wire feeding by a microprocessor, which can adopt a gas-protection-free flux-cored wire to perform arc semi-automatic welding; the interior of the welding machine is designed into an upper layer structure and a lower layer structure. The upper layer is mainly a wire feeding part, and the lower layer is mainly a welding transformer and a control circuit board part. The welding gun and the cable thereof, the workpiece clamp and the cable thereof, the power input line, the current or wire feeding speed adjusting potentiometer, the voltage adjusting potentiometer and the overheating protection indicator lamp are arranged on the front panel of the welding machine. The utility model discloses the welding machine has adopted the welding transformer elementary not to take a percentage to adopt microprocessor digital control circuit to carry out the voltage regulation and add the method of sending a control and solve the problem of taking a percentage welding machine in the past, realized that welding voltage is stepless, continuous wide range is adjusted, better solved the matching nature scheduling problem of welding voltage and electric current.

Description

Gas-free protective electric arc welding machine with microprocessor controlling voltage regulation and wire regulation

Technical Field

The utility model relates to a circuit and a structure of a gas-free protection arc semi-automatic welding machine which is controlled by a microprocessor to regulate pressure and wire; the power supply is 220-240V, and the frequency is 50 or 60 Hz. The flux-cored wire without gas protection can be adopted for arc semi-automatic welding; belong to electric welding control technology field.

Technical Field

At present, the market competition of the welding machine products which can adopt the flux-cored wire without gas protection to carry out the arc semi-automatic welding is very strong, not only reflects the advancement and the advantages of the technology, but also depends on the aspects of the performance, the cost or the price and the like of the welding machine to a great extent.

In foreign markets, the arc semi-automatic welding IGBT inverter welding machine can be carried out by adopting a flux-cored wire without gas protection, and the rated current of most products is generally at the level of 120-160A (the load duration rate is 30-20%). Due to the fact that the circuit of the welding machine is complex, the reliability is relatively poor, the price is high, later-period maintenance is difficult, and the like, market sales of the welding machine are influenced to a certain extent. In addition, because of the inverter welding machine, many welding machines cannot meet the requirement of EMC electromagnetic compatibility, and therefore cannot be exported to many countries (such as the united states, australia, etc.) or regions (such as the european union), which also has adverse effects on the manufacturing enterprises of the welding machines.

The welding machine which is controlled by adding the wire feeding control to the alternating current output of the tapped welding transformer or controlled by adding the wire feeding control to the direct current output of the tapped welding transformer and can adopt the flux-cored wire without gas protection to carry out the semi-automatic arc welding is still favored by foreign customers at present due to the reasons of simple structure, very low price, easy later maintenance and the like, and the product sales quantity is still very huge. However, the two welders have a common problem that the output voltage of the welder can only be regulated in a stepped or discontinuous manner, and the output voltage has a narrow variation range and poor stability. During welding, because the output current of the welding machine is large, and the load is an arc and is not a stable resistive load, the welding voltage is easily affected by the power supply voltage of a power grid and the fluctuation of the arc load, so that the stability of the output voltage is poor. In addition, since the welding voltage is adjusted in a stepwise manner, it is naturally impossible to achieve stepless or continuous welding voltage adjustment. Moreover, if output voltage adjustment in a wider range is to be realized, a large number of primary taps of the welding transformer are required, and the adjustment can only be realized by a multi-layer and multi-stage voltage change-over switch, so that the realization of multi-stage output voltage adjustment by the welding machine is not practical, and a great number of adverse effects can be brought to the manufacturing of the welding transformer, the installation of a connecting wire of the voltage change-over switch, the manufacturing process and the manufacturing cost of the whole machine, and the like. Therefore, product buyers and users remain a disinclination to both types of welders.

In order to solve the problems, American Lincoln electric welding machine manufacturing enterprises adopt a method that the primary stage of a welding transformer is not tapped, and an analog electronic control circuit is adopted to carry out voltage regulation and wire feeding control, so that a good practical welding application effect is obtained. The products developed by the welding machine are popular with users, but the products are naturally greatly restricted in sales due to the fact that the adopted analog control circuit is complex, the working stability and consistency are easily influenced by temperature and discreteness of components, the manufacturing cost is high, the sales price of the welding machine is more unacceptable to users, and the like.

Therefore, the utility model discloses the welding machine has adopted welding transformer elementary not to take a percentage to adopt microprocessor digital control circuit to carry out the pressure regulating and add the method of sending a control and solve above-mentioned problem, also gained better actual welding application effect equally. The developed product adopts the microprocessor digital control technology, so that the control circuit is greatly simplified, the adverse factors such as the discreteness of components, the temperature and the like are greatly reduced, the manufacturing cost of the product is low, and the sale price of the welding machine is low. Meanwhile, because a system digitally controlled by a microprocessor is adopted, the adverse factors such as the discreteness of components, the temperature and the like are greatly reduced, and therefore, the stability of the system is greatly improved. Just for the above reasons, the product sales are more competitive in the market, and the products are also more popular with users. The utility model adopts armature voltage negative feedback and current compensation control, which realizes the stable wire feeding speed and the adjustment in a larger range; the bidirectional light-controlled thyristor or the controllable silicon and the digital control trigger circuit thereof are adopted, and the bidirectional thyristor or the controllable silicon which are connected in series in the primary loop of the welding transformer are utilized to realize stepless and continuous wide-range regulation of welding voltage; the matching of welding voltage and current is better, thus improving the technical content of products and being beneficial to the product competition of international market.

The utility model discloses welding machine can adopt the flux cored wire of no gas protection to carry out electric arc semi-automatic welding. The power supply of the welding machine is 220-240V, and the frequency is 50 or 60 Hz. The requirements of safety and electromagnetic compatibility certification of the electric welding machine can be met, and the control requirements of output voltage regulation (voltage regulation for short) and wire feeding speed regulation (wire regulation for short) and overheating protection state indication of the electric welding machine are realized by utilizing the microprocessor control circuit. In addition, anti-interference and other filtering measures are adopted in the aspects of the design of the whole machine and the circuit board and control software, such as a capacitor filter circuit, an X capacitor and a Y capacitor filter circuit, wherein the Y capacitor is connected between the input line and the ground and is used for eliminating common-mode interference; the X capacitor is connected to two ends of the input line and is used for eliminating differential mode interference; controlling the power supply and the electrical isolation of the transformer; electrically isolating the light-operated bidirectional thyristor or thyristor; therefore, the work reliability of the control circuit of the welding machine can be improved while the EMC electromagnetic compatibility requirement is met. This has obvious technical features and performance advantages in similar products. Furthermore, the utility model discloses the welding machine has carried out optimal design to control circuit board, can adopt automatic plug-in components, automatic paster, automatic weld and abluent advanced manufacturing process to make, has reduced manufacturing cost. In addition, because the control connecting wires of the whole machine are less, the manufacturing efficiency of the product is improved. By adjusting a small number of parts (such as welding transformers and the like), series products with different specifications can be easily formed. The utility model discloses the circuit principle of welding machine, circuit board and complete machine structural design have own unique part. The object of this patent is to protect the design of the welder.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a microprocessor control pressure regulating transfers non-gas protection electric arc semi-automatic welding machine who send. The arc semi-automatic welding can be carried out by adopting a flux-cored wire without gas protection. The utility model adopts the microprocessor digital control circuit to realize the control requirements of output voltage regulation (short for pressure regulation) and wire feeding speed regulation (short for wire feeding) of the welding machine and the indication of overheat protection state, and adopts armature voltage negative feedback and current compensation control to realize the stable and wide range regulation of wire feeding speed; the bidirectional light-controlled thyristor or the controllable silicon and the digital control trigger circuit thereof are adopted, and the bidirectional thyristor or the controllable silicon which are connected in series in the primary loop of the welding transformer are utilized to realize stepless and continuous wide-range regulation of welding voltage; the matching of welding voltage and current is better, and simultaneously, because of adopting a microprocessor digital control system, the adverse factors such as component discreteness, temperature and the like are greatly reduced, so the stability of the system is greatly improved. Therefore, the technical content of the product is improved, the product cost and the price are reduced, and the product competition in the international market is facilitated. Measures such as anti-interference filtering, electrical isolation and the like are adopted in the aspects of the design of the whole machine and a circuit board and control software, such as a capacitor filter circuit, an X capacitor and a Y capacitor filter circuit, wherein the Y capacitor is connected between an input line and the ground and is used for eliminating common-mode interference; the X capacitor is connected to two ends of the input line and is used for eliminating differential mode interference; controlling the power supply and the electrical isolation of the transformer; bidirectional light-controlled thyristors or controllable silicon electrical isolation and the like; therefore, the work reliability of the control circuit of the welding machine is improved while the EMC electromagnetic compatibility requirement is met. This has obvious technical features and performance advantages in similar products. Furthermore, the utility model discloses the welding machine has carried out optimal design to control circuit board, can adopt automatic plug-in components, automatic paster, automatic weld and abluent advanced manufacturing process to make, has reduced manufacturing cost. In addition, because the control connecting wires of the whole machine are less, the manufacturing efficiency of the product is improved.

The utility model discloses the power supply of welding machine is 220 ~ 240V, and the frequency is 50 or 60 Hz. The main components of the welder include:

1) the wire feeding part mainly comprises a wire feeder and a fixing screw thereof, a welding wire disc shaft and a fixing screw thereof, and a wire feeding control circuit part on a control circuit board; the wire feeder and the wire reel shaft are arranged on the inner middle partition plate, the wire feeder is close to the right front surface of the middle partition plate of the welding machine, and the middle partition plate is provided with corresponding mounting holes; the wire feeder is connected with a welding cable of a welding gun assembly arranged on a front panel of the welding machine; 0.5 or 1Kg of gas-free shielded flux-cored wire is installed on a welding wire reel shaft, the welding wire can be sent into a wire feeder after being installed, and then enters a welding gun through a wire feeding wheel and a pressing wheel of the wire feeder, and the welding wire can extend out of a contact tip of the welding gun under the action of the wire feeder and a control circuit thereof. During welding, the wire feeding speed of the welding wire is controlled by the circuit board and the corresponding wire feeding speed or the current adjusting potentiometer, and the welding current can be changed by adjusting the wire feeding speed.

2) The shell part comprises an upper cover plate, a rotating shaft of the upper cover plate, a clamping ring I of the rotating shaft of the upper cover plate, a clamping ring II of the rotating shaft of the upper cover plate, a left side cover plate, a right side cover plate, a U-shaped bottom plate of the shell, a bottom support leg and a fastening screw thereof, a fastening screw of the side cover plate and a middle partition plate.

3) On the rear panel of U type casing bottom plate, the spare part of installation has cooling fan, adopts the set screw to install on the rear panel. The cooling fan performs forced air cooling on some parts inside the welding machine. The cooling fan is positioned at the rear part of the welding machine, and cold air enters from an air inlet at the rear part of the rear panel of the welding machine case, so that the welding transformer and some heating devices or parts on the control circuit board, such as a bidirectional thyristor or a thyristor, a radiator and the like, can be well cooled.

4) On the front panel of the U-shaped casing bottom plate, the mounted parts mainly comprise a power switch, a current or wire feed speed adjusting potentiometer and a knob, a voltage adjusting potentiometer and a knob, an overheating protection indicator lamp, a workpiece clamp and a welding cable thereof, a pull-off of the workpiece clamp and the welding cable thereof (also called a wire fixing device), a power supply input power wire and a pull-off thereof, a sheath of the welding cable at the rear part of the welding gun, the welding gun and the welding cable thereof, wherein the sheath of the welding cable at the rear part of the welding gun is fixed on the front panel by adopting a fastening nut at the rear part of the; the workpiece clamp and the welding cable thereof are used for connecting welded parent metal; the input power line is connected to a power supply grid; the power switch controls the on or off of the power supply of the welding machine; the current or wire feeding speed regulating potentiometer is used for regulating the welding current or the wire feeding speed; the voltage regulating potentiometer is used for regulating the welding voltage.

5) The inner part of the welding machine is divided into two layers by a middle clapboard, and the middle clapboard is fixed on the front panel and the rear panel of the bottom plate of the U-shaped machine shell by screws; the upper layer of the middle partition board is provided with parts of the wire feeding part; a welding transformer is arranged on a bottom plate of the U-shaped machine shell on the lower layer of the middle partition plate, the welding transformer adopts two bottom supports as supports and is fixed on the bottom plate of the U-shaped machine shell by fastening screws; the overheating protector or the temperature controller is arranged on the welding transformer, and the temperature sensing surface of the overheating protector or the temperature controller is tightly attached to the surface of a winding wire of the welding transformer, so that the temperature of a transformer winding can be detected well; the control circuit board adopts two fixed brackets as supports and is fixed on the bottom plate of the U-shaped chassis bottom plate by screws.

When the temperature of a winding wire of a welding transformer in the welding machine is too high and exceeds the action temperature of an overheat protector or a temperature controller, under the action of a control circuit, on one hand, an overheat phenomenon can be indicated through an overheat protection indicator lamp, and on the other hand, the welding machine can stop welding or output. In the condition that the welding machine does not output, the temperature of the winding wire of the welding transformer is reduced by the action of the cooling fan. When the recovery action temperature of the overheat protector or the temperature controller is reduced, the heat protector recovers, the overheat phenomenon of the welding machine is eliminated, the overheat protection indicator lamp is extinguished, and meanwhile, the welding machine can be used for welding again. The design is beneficial to protecting the welding transformer and preventing the welding transformer from being burnt out due to overheating.

For the control board circuit part, its externally connected devices or parts are connected with the corresponding sockets on the circuit board through plugs and control lines thereof, for example, the wire feeding motor, the welding gun switch, the overheat protector or temperature controller, the overheat protection indicator light, and the current or wire feeding speed and voltage regulation potentiometer are connected with the control circuit board.

The utility model discloses welding machine, a small amount of spare part specification parameter on design, the circuit board of accessible adjustment welding transformer, form the product of different output rated current and load continuation rate, make the product serialization. For example, changing the current level and load duration of the welding transformer; the series products with different specifications can be easily formed by changing the model, parameters and the like of the bidirectional controllable silicon or the thyristor. These variations, of course, aim to match the production costs of the product with the specifications and performance specifications of the respective machine. In this way, each specification type of welder can achieve optimal cost control. This enhances the market competitiveness of the developed product.

The utility model discloses the welding machine has adopted welding transformer elementary not to take a percentage to adopt microprocessor digital electronic control circuit to carry out the pressure regulating and add the method of sending a control and solve above-mentioned problem, also gained better actual welding application effect equally. The developed product adopts microprocessor digital control technology, so that the control circuit is greatly simplified, the manufacturing cost of the product is low, and the sale price of the welding machine is low. In addition, because the system adopting the microprocessor for digital control greatly reduces the disadvantages of component discreteness, temperature and the like, the stability of the system is greatly improved. Just for the above reasons, the product sales are more competitive in the market, and the product sales are also greatly popular with users. The utility model adopts armature voltage negative feedback and current compensation control, which realizes the stable wire feeding speed and the adjustment in a larger range; by adopting the bidirectional light-controlled thyristor or the controllable silicon and the digital control trigger circuit thereof and utilizing the bidirectional thyristor or the controllable silicon which is connected in series in the primary loop of the welding transformer, stepless and continuous wide-range adjustment of welding voltage is realized, and the matching property of the welding voltage and the welding current is better, so that the technical content of products is improved, meanwhile, the product cost and the price are also reduced, and the product competition of the international market is facilitated.

The utility model discloses welding machine can adopt the flux cored wire of no gas protection to carry out electric arc semi-automatic welding. The power supply is 220-240V, and the frequency is 50 or 60 Hz. The requirements of safety and electromagnetic compatibility certification of the electric welding machine can be met, and the control requirements of output voltage regulation (voltage regulation for short) and wire feeding speed regulation (wire regulation for short) and overheating protection state indication of the electric welding machine are realized by utilizing the microprocessor control circuit. The design of the whole machine and the circuit board and the aspect of control software adopt anti-interference and other filtering measures, so that the work reliability of the control circuit of the welding machine can be improved while the EMC electromagnetic compatibility requirement is met. This has obvious technical features and performance advantages in similar products. Furthermore, the utility model discloses the welding machine has carried out optimal design to control circuit board, can adopt automatic plug-in components, automatic paster, automatic weld and abluent advanced manufacturing process to make, has reduced manufacturing cost. In addition, because the control connecting wires of the whole machine are less, the manufacturing efficiency of the product is improved. Meanwhile, series products with different specifications can be easily formed by adjusting a small number of parts (such as welding transformers and the like). Therefore, the utility model discloses the circuit principle, circuit board and the complete machine structural design of welding machine have own unique part. The object of this patent is to protect the design of the welder.

Drawings

FIG. 1 is a schematic structural view of an exemplary welding machine made in accordance with the present invention;

FIG. 2 is a schematic circuit diagram of the welding machine of the present invention;

the names of the components in figure 1 are as follows: 1. a snap ring I of the rotating shaft of the upper cover plate; 2. a rotating shaft of the upper cover plate; 3. A snap ring II of the rotating shaft of the upper cover plate; 4. An upper cover plate; 5. Fastening screws of the side cover plate; 6. A left side cover plate; 7. A fixing screw of the welding wire reel shaft; 8. A wire spool; 9. A fixing screw of the wire feeding mechanism; 10. A wire feeder; 11. A welding machine contact tip; 12. A middle partition plate; 13. A right side cover plate; 14. Welding a transformer; 15. An overheat protector or a temperature controller; 16. Welding a fastening screw of a bracket at the bottom of the transformer; 17. Welding a bottom bracket of the transformer; 18. A fastening screw of the cooling fan; 19. A cooling fan; 20. A U-shaped chassis base plate; 21. A fastening nut at the rear of the welding gun; 22. A fixing bracket of the control circuit board; 23. A control circuit board; 24. A power switch; 25. Current or wire feeding speed regulating potentiometer and knob; 26. A voltage regulating potentiometer and a knob; 27. An overheat protection indicator light; 28. A work clamp and its welding cable; 29. A work clamp and its welding cable; 30. A power supply line and a plug thereof; 31. A power supply line; 32. Welding a sheath of the cable at the rear part of the welding gun; 33. A welding gun and a welding cable thereof; 34. Bottom support leg and its fastening screw.

Detailed Description

As shown in the attached figure 1, the attached figure 1 is a schematic structural design diagram of a gas-free protective arc semi-automatic welding machine which is made by utilizing the utility model to control the pressure regulation and wire feeding of a microprocessor, and the main components of the welding machine comprise:

1) the wire feeding part mainly comprises a wire feeder 10 (the number represents the serial number of the parts in the attached drawing 1, and the description is not repeated below), a fixing screw 9 of the wire feeder, a wire reel shaft 8, a fixing screw 7 of the wire reel shaft, and a wire feeding control circuit part on a control circuit board. Wire feeder 10 and wire drum shaft 8 are mounted on an internal bulkhead 12. The wire feeder 10 is located near the right front of the welding machine center bulkhead 12, and the center bulkhead 12 has corresponding mounting holes. The wire feeder 10 is connected to the weld cable of a gun assembly 33 mounted on the front panel of the welder. 0.5 or 1Kg of the gas-free flux-cored wire is mounted on the wire reel shaft 8. The welding wire may be fed into the wire feeder 10 after being installed, and may enter the welding gun through the wire feeding wheel and the pressing wheel of the wire feeder 10, and may be extended from the contact tip of the welding gun 33 under the action of the wire feeder 10 and the control circuit thereof. During welding, the wire feeding speed of the welding wire is controlled by the circuit board and the corresponding wire feeding speed or the current regulating potentiometer. The welding current can be changed by adjusting the wire feeding speed.

2) The shell part comprises an upper cover plate 4, a rotating shaft 2 of the upper cover plate, a clamping ring I1 of the rotating shaft of the upper cover plate, a clamping ring II 2 of the rotating shaft of the upper cover plate, a left side cover plate 6, a right side cover plate 13, a U-shaped shell bottom plate 20, bottom support legs and fastening screws 34 thereof, fastening screws 5 of the side cover plate and a middle partition plate 12.

3) On the back panel of the U-shaped chassis base plate 20, the mounted components are cooling fans 19 mounted on the back panel by fixing screws 18. The cooling fan 19 performs forced air cooling of some parts inside the butt welding machine. The cooling fan 19 is located at the rear part of the welding machine, and cold air enters from an air inlet hole at the rear part of the rear panel of the welding machine case, so that the welding transformer 14 and some heating devices or parts on the control circuit board 23, such as a bidirectional thyristor or a thyristor, a radiator and the like, can be well cooled.

4) On the front panel of the U-shaped chassis 20, the mounted components mainly include a power switch 24, a current or wire feed speed adjusting potentiometer and knob 25, a voltage adjusting potentiometer and knob 26, an overheat protection indicator lamp 27, a work holder and a welding cable 28 thereof, a pull-off (also called a wire fixing device) 29 of the work holder and the welding cable thereof, a power supply input power line 30 and a pull-off (also called a wire fixing device) 31 thereof, a sheath 32 of the welding cable at the rear part of the welding gun, the welding gun and a welding cable 33 thereof, wherein the sheath 32 of the welding cable at the rear part of the welding gun is fixed on the front panel by a fastening nut 21 at the rear part of the welding gun; the work holder and its welding cable 28 are used for connecting the welded parent metal; the input power line 30 is connected to the power supply grid; the power switch 24 controls the on/off of the power supply of the welding machine; the current or wire feeding speed regulating potentiometer is used for regulating the welding current or the wire feeding speed; the voltage regulating potentiometer is used for regulating the welding voltage.

5) The inner part of the welding machine is divided into two layers by a middle clapboard 12, and the middle clapboard 12 is fixed on the front and the rear panels of a U-shaped chassis bottom plate 20 by screws; the upper layer of the middle partition plate 12 is provided with parts of a wire feeding part; a welding transformer 14 is arranged on the bottom plate of a U-shaped casing bottom plate 20 at the lower layer of the middle partition plate 12, and the welding transformer 14 adopts two bottom brackets 17 as supports and is fixed on the bottom plate of the U-shaped casing bottom plate 20 by fastening screws 16; the overheat protector or the temperature controller 15 is arranged on the welding transformer 14, and the temperature sensing surface of the overheat protector or the temperature controller 15 is tightly attached to the surface of a winding wire of the welding transformer 14, so that the temperature of a transformer winding can be detected well; the control circuit board 23 is supported by two fixing brackets 22 and is fixed to the bottom plate of the U-shaped chassis bottom plate 20 by screws.

When the temperature of the winding wire of the welding transformer 14 in the welding machine is too high and exceeds the action temperature of the overheat protector or the temperature controller 15, under the action of the control circuit, on one hand, the overheat protection indicator lamp 27 can indicate that the overheat phenomenon occurs, and on the other hand, the welding machine can stop welding or outputting. In the event that the welder is not outputting, the cooling fan will act to lower the temperature of the winding wire of the welding transformer 14. When the recovery action temperature of the overheat protector or the temperature controller 15 is lowered, the overheat protector is recovered, the overheat phenomenon of the welding machine is eliminated, the overheat protection indicator lamp 27 is turned off, and at the same time, the welding machine can be used for welding again. The design is beneficial to protecting the welding transformer and preventing the welding transformer from being burnt out due to overheating.

FIG. 2 shows a schematic diagram of a control circuit of the welding machine, which mainly comprises a main circuit, a DC power supply circuit, a zero crossing point detection or synchronous detection circuit of AC waveform of a power grid, a setting and detection circuit of welding parameters of current or wire feeding speed and voltage, a welding gun switching signal detection circuit, a welding output voltage detection and conversion circuit, a welding voltage output and regulation control circuit, a wire feeding control circuit, an overheat protection control and indication circuit part.

The utility model discloses the theory of operation of welding machine circuit briefly states as follows:

1) as shown in figure 2, a main circuit of the welder comprises a power input switch S1, a common-mode filter inductor T3, R301-R302 resistors, filter capacitors C11, C13 and C29, a bidirectional thyristor or thyristor Q1 and a welding transformer T2. 220V-240V alternating current from a power grid firstly passes through a power switch S1 and then is connected with a common mode filter inductor T3 and a cooling FAN FAN. The mains power is switched on through a power switch S1 on the front panel of the welder. And then, the input power passes through a filter circuit consisting of a common-mode filter inductor T3, R301-R302 resistors, a filter capacitor C11, C13 and C29. After the resistors R301-R302 are connected in series, the resistors and the capacitor C29 are connected in parallel at two ends of a common mode filter inductor T3; the C11 and C13 filter capacitors are respectively connected to two ends of a power supply line, and the middle connection point of the two capacitors is connected to the frame or ground end of the welding machine and is connected with a protective grounding wire in a power supply system; the C11 and C13 filter capacitors belong to Y capacitors and are connected between the input line and the ground for eliminating common-mode interference; the C29 capacitor belongs to an X capacitor and is connected to two ends of an input line for eliminating differential mode interference and improving the working reliability of a control circuit of the welding machine. The large current path of the bidirectional thyristor or thyristor Q1 is connected in series in the primary loop of the welding transformer T2, and the two ends of the large current path of the bidirectional thyristor or thyristor Q1 and the control electrode thereof are connected with the control circuit; the secondary of the welding transformer T2 is the output end of the welding machine, which is connected with the grounding clip and the welding cable, the welding gun and the welding cable, and the output end of the welding machine is connected with the welding output voltage detecting and converting circuit. The output of the welding machine can be realized by controlling the conduction of the bidirectional thyristor or the thyristor Q1; the adjustment of the output voltage of the welding machine can be realized by changing or adjusting the trigger pulse phase of the bidirectional thyristor or thyristor Q1 or the conduction angle of Q1; the stepless continuous regulation of the output voltage of the welding machine can be realized by continuously changing the phase or the conduction angle of the trigger pulse of the Q1.

2) The direct current power supply circuit part is shown in figure 2 and comprises a T1 power supply transformer, D4-D9 diodes, a U4 (7805) and U6 (7815) integrated voltage stabilizer and C12, C14 and C15 electrolytic capacitors around the D4-D9 integrated voltage stabilizer to generate +5V and +15V direct current power supply voltages to supply to corresponding control circuits for electrified operation. The +5V stable direct-current power supply voltage is used as a working power supply of a circuit system of the microprocessor U2; the +15V stabilized dc supply voltage serves as the operating power supply for operational amplifiers and other circuits. The primary of the T1 power transformer is connected in parallel at the two output ends of the common mode filter inductor T3, and the T1 power transformer not only supplies power to the power circuit, but also plays a role in electrically isolating the high-voltage circuit from the low-voltage circuit, thereby ensuring the safe and reliable work of the control circuit. The circuit is a relatively common and classical circuit, the working principle of which is relatively simple, and the description is not repeated here.

3) An overheating protection control and indication circuit thereof is shown in figure 2, two ends of a J3 socket interface are connected to a normally closed overheating protector or a temperature controller WKQ, and WKQ is installed on the winding surface of a welding transformer T2 in a clinging mode; the 2-pin connection resistor R16 of the J3, and the other end of the R16 is connected with a +15V power supply; the 2 pin of J3 is connected with a resistor R18, the other end of R18 is connected with the 13 pin of a microprocessor U2 and the anode of a diode V3, the cathode of a diode V3 is connected with +5V, and an R19 resistor and a C8 capacitor are connected between the 13 pin of U2 and the ground in parallel; the 16 feet of the microprocessor U2 are connected with a resistor R12, the other end of R12 is connected with the 1 foot of the OH or J4 socket interface, and the 2 foot of the OH or J4 socket interface is grounded; the pins 1 and 2 of the socket interface of OH or J4 are also connected with an overheat protection indicator lamp, namely an LED Y light-emitting diode, on the front panel of the welding machine through a plug and a control line thereof, and the anode of the light-emitting diode is connected with the pin 1 of the socket interface of OH or J4; when WKQ is not operated, pin 13 of U2 can detect +5V high level, pin 16 of U2 outputs low level, and overheat protection indicator light LED Y is not lighted and shines; on the other hand, when WKQ is operated, pin 13 of U2 can detect low level, on one hand, the high level of +5V is output through pin 16 of microprocessor U2, so that overheat protection indicator lamp LED Y can light up and emit light to indicate that overheat protection occurs to users, on the other hand, pin 11 of U2 outputs low level, light emitting diode in U5 light-operated bidirectional thyristor or thyristor can not emit light, bidirectional thyristor or thyristor at output stage can not be conducted, bidirectional thyristor or thyristor Q1 in main circuit can not be conducted, thus, welding machine can not output and weld. At the same time, the output control signals from

pins

19 and 20 of U2 will cause the wire feed control circuit to stop feeding wire. This prevents the welder from burning out the welding transformer T2 due to overheating, thereby achieving the purpose of protecting the welder. Under cooling blower's effect, after welding transformer T2's temperature dropped to the certain degree, the inside overheated phenomenon of welding machine was eliminated, and when the heat protector recovered, welding process could just continue, and the indicator lamp that crosses heat simultaneously also can extinguish.

4) The Current or wire feeding speed and Voltage welding parameter setting and detection circuit is shown in figure 2, a Voltage (Voltage) adjusting potentiometer RP1 on the front panel of the welding machine, and a Current or wire feeding speed (Current) adjusting potentiometer RP2 are connected with a control panel part through a plug J2; one fixed ends of RP1 and RP2 are grounded, the other fixed ends of RP1 and RP2 are respectively connected with resistors R10 and R8, the other ends of R10 and R8 are connected with +5V, the middle sliding ends of RP1 and RP2 are respectively connected with resistors R11 and R9, the other end of R11 is connected with a capacitor C4 and a pin 6 of a microprocessor U2, the other end of R9 is connected with a capacitor C3 and a pin 5 of a microprocessor U2, and the other ends of C3 and C4 are grounded; by sampling the 6 and 5 pins of U2 and performing analog-to-digital conversion, the microprocessor U2 system can obtain the set values of welding voltage, current or wire feeding speed selected by the user.

5) A power grid alternating current waveform zero crossing point detection or synchronization detection circuit is shown in figure 2 and comprises a T1 power transformer, diodes D5-D6 and D8-D9, an operational amplifier U1A, resistors R1-R7, capacitors C1 and C2, a diode V1, +15V and a +5V power supply, wherein the power transformer is arranged at the position of a direct current power circuit; +15V is used as the working power supply of the circuit part of the operational amplifier U1A; the input of the bridge rectifier circuit consisting of diodes D5-D6 and D8-D9 is connected with the secondary output of the T1, and the output waveform signal of the bridge rectifier circuit is + VA; the microprocessor U2 control system can obtain the zero crossing point time or the synchronous reference point of the power grid alternating current waveform by detecting the output signal + VA through the 8 pins of the microprocessor U2 control system, and determines the trigger pulse phase or the conduction angle of the Q1 tube in the control main circuit according to the reference point and the given value of the output voltage of the welding machine; one end of the R6 is connected with a signal + VA, the other end of the R6 is connected with the inverting input end of the operational amplifier U1A, and the inverting input end is connected with C2 and R7 in parallel between the ends of the inverting input end and the ground; c1 and R3 are connected in parallel between the non-inverting input terminal of the operational amplifier U1A and the ground, the non-inverting input terminal is connected with R1 and R2, the other end of R2 is connected with +15V, the other end of R1 is connected with the output terminal of the operational amplifier U1A, the output terminal is connected with R5, the other end of R5 is connected with the anodes of R4 and V1 and the pin 8 of U2, the cathode of V1 is connected with +5V, and the other end of R4 is connected with the ground; the V1 diode acts to limit the 8-pin input of U2 from exceeding the limit level.

6) The welding voltage output and regulation control circuit is shown in figure 2 and comprises a microprocessor U2 control system, a light-operated bidirectional thyristor or thyristor U5, a bidirectional thyristor or thyristor Q1 in a main circuit, capacitors C6 and C10, resistors R13, R25, R27, R20-R22 and a piezoresistor FU 1; the pin 11 of U2 is connected with resistor R13, the other end of R13 is connected with the anode of the LED in the C6 and U5 light-controlled bidirectional thyristor or thyristor, the cathode of the LED and the other end of C6 are grounded; one end of an output stage bidirectional thyristor or thyristor in the U5 light-controlled bidirectional thyristor or a pin 6 of the U5 is connected with R27, R22, R20 and R21 which are connected in series, the other end of R21 is connected with R25 and C10, and the other ends of R25 and C10 are respectively connected with two ends of a bidirectional thyristor or thyristor of Q1 in the main circuit; two ends of the Q1 are connected with a piezoresistor FU1 in parallel, so that the Q1 is prevented from overvoltage breakdown; when the welder welds, the microprocessor U2 control system will detect the signal, if it is too hot; given the welding voltage sampling data, it is determined whether the pin 11 of the microprocessor U2 outputs a low level control signal or outputs a trigger pulse phase signal or conduction angle magnitude for controlling the conduction of the triac or thyristor in U5 and Q1. The output of the welding machine can be realized by controlling the conduction of the bidirectional thyristors or thyristors in the U5 and the Q1; the output voltage of the welding machine can be adjusted by changing or adjusting the trigger pulse phase or the conduction angle of the bidirectional thyristors or thyristors in the U5 and the Q1; the stepless continuous regulation of the output voltage of the welding machine can be realized by continuously changing the trigger pulse phase or the conduction angle of the control signal.

When the operator adjusts the potentiometer of the welding voltage on the front panel and performs welding, the control circuit can detect a feedback signal of the voltage of the power grid. During welding, the output voltage is determined by the welding voltage given signal and the feedback signal of the grid voltage. The object or target of control is the output voltage magnitude. Under the action of the control circuit, the output voltage of the welding machine is determined through the output signal of the pin 11 of the U2, and the accurate control of the output voltage parameters is realized. The method is characterized in that: the load current changes greatly, and the output voltage changes little, and remains relatively stable. Only when the voltage given signal changes does the output voltage change significantly. The above control process is realized by a corresponding control circuit.

7) A welding gun switch signal detection circuit is shown in figure 2 and comprises a J5 socket interface, a capacitor C7, resistors R14-R15 and R17, and diodes V2, a +15V power supply and a +5V power supply; a welding Gun Switch (Gun Switch) is connected to the J5 socket interface through a plug and a control line thereof; one end of the welding gun switch is connected with R14, and the other end of R14 is connected with + 15V; the other end of the welding gun switch is connected with R15, the other end of R15 is connected with the anode of V2, R17, C7 and pin 1 of microprocessor U2, the other ends of R17 and C7 are grounded, the cathode of V2 is connected with +5V power supply, and the V2 diode plays a role in limiting the input of pin 1 of U2 not to exceed a limiting level; when the torch Switch (Gun Switch) is not closed, pin 1 of U2 may detect a low level; conversely, when the Gun Switch (Gun Switch) is closed, pin 1 of U2 may detect a high level. The microprocessor control system can know whether the welding gun switch is closed or not by detecting the 1 pin level state of the U2.

8) The welding output voltage detection and conversion circuit is shown in figure 2 and comprises a BD1 rectifier bridge and an E1 electrolytic capacitor, wherein the input end of the BD1 rectifier bridge is connected in parallel with the secondary output end of a welding transformer T2, and the output end of the BD1 rectifier bridge is connected in parallel with the E1 electrolytic capacitor, so that an MVCC + direct current voltage signal is finally obtained and the output voltage of a welding machine is reflected.

9) The wire feeding control circuit is shown in figure 2 and comprises a J6 socket interface, field effect transistors Q5 and Q6 (IRF 740), diodes V4, V5, D2 and D3, NPN type triodes N1 and Q3, PNP type triodes Q2 and Q4, operational amplifiers U3A and U3B, a wire feeding motor fuse F1, capacitors C9, C16-C17 and C20, an electrolytic capacitor E2, resistors R28-R43, R26, R23-R24 and a +15V and +5V power supply; +15V as the working power supply for the operational amplifier U3A and U3B circuit parts; the Wire feeding motor (Wire feeder) is connected to the J6 socket interface through a plug and a control Wire thereof; pin 1 of J6 is positive; the rated voltage of the wire feeding motor is 24V and is connected between MOT + and MOT-, and the wire feeding motor belongs to a component of the wire feeding machine shown in the attached figure 1. When output voltage exists between the two terminals of MOT + and MOT-, the wire feeding motor connected to the interface is operated, and wire feeding control can be realized. Otherwise, the wire feeder will not rotate and will not feed wire. The D end of the Q5 is connected with a fuse tube F1, and the other end of the fuse tube F1 is connected with an MVCC + direct-current voltage signal end in the welding output voltage detection and conversion circuit; the pin 1 of the J6 is connected with the S end of the Q5, the R24, the R34, the R29, the negative polarity end of the electrolytic capacitor E2 and the collector of the Q4; the other end of the R24 is connected with a non-inverting input end of the U3A, the non-inverting input end is connected with the ground in parallel with C20 and R26, the inverting input end of the U3A is connected with the output end, and a circuit of the operational amplifier part forms a voltage follower; the output end of U3A is connected with R23, the other end of R23 is connected with C9, pin 3 of microprocessor U2 and the anode of V4, the cathode of V4 is connected with +5V, and the other end of C9 is grounded; the V4 diode acts to limit the 3-pin input of U2 from exceeding the slice level; the detection signal obtained by the pin 3 of the microprocessor U2 is a voltage negative feedback signal of the wire feeding motor; the other end of R29 is connected with the base of Q4, the collector of Q2 and the anode of D3, the cathode of D3 is connected with R33, and the other end of R33 is connected with the emitter of Q4 and the G end or the control electrode of Q5; the positive polarity end of the electrolytic capacitor E2 is connected with the cathode of D2, the emitter of Q2 and R28, the other end of R28 is connected with the base of Q2 and the collector of Q3, the emitter of Q3 is connected with R32, the other end of R32 is grounded, the base of Q3 is connected with R30, and the other end of R30 is connected with R31 and the 19 pins of the microprocessor U2; the other end of R31 is grounded; the other end of R34 is connected with the D end of Q6; the S end of the Q6 is connected with the 2 pins of R37, R40 and J6, and the other end of R37 is grounded; the G end or the control end of Q6 is connected with R36, the other end of R36 is connected with the collectors of R35 and N1, the other end of R35 is connected with +15V, the emitter of N1 is grounded, the base of N1 is connected with R41, the other end of R41 is connected with R43 and the 20 pin of the microprocessor U2, and the other end of R43 is connected with + 5V; one end of R40 is connected with pin 2 of J6, the other end of R40 is connected with the non-inverting input end of U3B and C16, and the other end of C16 is grounded; the inverting input end of U3B is connected with R38 and R39, the other end of R38 is connected with the output end of U3B and R42, and the other end of R42 is connected with the anodes of C17 and V5 and pin 2 of U2; the detection signal obtained by pin 2 of the microprocessor U2 is a current feedback signal of the wire feeding motor, and the sampling resistance of the signal is R37; r37 is a current sampling resistor connected in series in the loop of the wire feeding motor, through which the armature current feedback signal of the wire feeding motor can be obtained; the other end of the C17 is grounded, the cathode of the V5 is connected with +5V, and the V5 diode plays a role in limiting the input of the pin 2 of the U2 not to exceed a limiting level; the other end of R39 is grounded; the fuse tube F1 limits the current flowing through the wire feed motor to prevent the motor from being burned out due to excessive current when the motor is locked.

The utility model discloses in, the control algorithm has adopted armature voltage negative feedback and current compensation control or positive feedback's control mode to and the mode of current-limiting protection realizes sending steady speed, the stall control of silk motor. For example, when the phenomena of long-time wire blockage of welding wires and motor blockage occur in the welding process, the control system can detect a large motor current feedback signal through pins 2 of R37 and U2, and send a corresponding control instruction to stop supplying power to the wire feeding motor and stop rotating the wire feeding motor; when the wire feeding speed is reduced due to the increase of wire feeding resistance (for example, the welding wire is subjected to a larger bending action in a welding gun) in the welding process, the wire feeding speed is increased and the stability of the wire feeding speed is maintained due to the control action of current compensation control or positive feedback, so that the stability of the welding process is facilitated; when the armature voltage of the wire feeding motor changes due to the voltage fluctuation of the power grid, and further the wire feeding speed changes, the armature voltage negative feedback signal of the wire feeding motor can be obtained through the 3 pins of the microprocessor U2, and the armature voltage of the wire feeding motor changes along with the armature voltage negative feedback through the control of the control system, so that the wire feeding speed is finally stable. The method is beneficial to the stability of the welding process and provides technical guarantee for obtaining good welding seam quality.

When a control signal output by a pin 19 of the microprocessor U2 enables the field effect transistor Q5 to be conducted and the welding transformer T2 of the welding machine outputs voltage, the wire feeding motor can obtain working voltage MVCC +, the motor can rotate, and the wire feeding mechanism drives a welding wire to feed; and on the contrary, when the Q5 is cut off, the wire feeding is stopped.

The control signal output by the pin 20 of the U2 is a control signal for stopping the wire feeding of the wire feeding control circuit, and when the wire feeding is stopped, the dynamic braking mode is adopted, and the braking resistor is R34. When the Q6 is conducted, the R34 is connected into an armature loop of the wire feeding motor, energy stored on a motor winding is quickly consumed, energy consumption braking control is carried out on the wire feeding motor, the welding wire is quickly stopped to be fed, the welding wire is prevented from extending out of a contact tip of a welding gun to be too long to influence the normal operation of welding, and the phenomenon that the welding wire is inserted into an unsolidified molten pool to cause wire sticking is avoided.

The J1 socket interface in fig. 2 is a program programming interface for the microprocessor for writing the control program.

According to the above, the utility model discloses welding machine, when the power supply of switch-on welding machine, installed the flux cored wire that does not have gas protection and made it stretch out welder's contact tip certain distance after, through the potentiometre on the welding machine front panel, adjusted wire feed speed or electric current, voltage parameter to after being connected and being welded mother metal or work piece, can begin to weld. When welding, the welding gun switch is pressed down, the microprocessor control system detects that the welding gun switch is closed, at the moment, Q1 in the main circuit is conducted according to a corresponding conduction angle, the welding machine outputs corresponding voltage, meanwhile, the welding wire carries out stable wire feeding according to the set wire feeding speed, and after the welding wire contacts with a welding base metal or a workpiece, a welding arc can be ignited. Then the electric arc burns stably, the welding wire melts, and the welding process can be carried out at a certain welding speed. If the welding current is required to be changed, the wire feeding speed potentiometer on the front panel is adjusted; if the welding voltage is adjusted, the voltage on the front panel is adjusted to be set to a potentiometer. When the welding operation is to be stopped, the welding gun switch is turned off, the control system stops feeding wires and the output voltage of the welding machine is turned off. The above process is the simple operation process of the welding machine of the utility model. The operation control of the corresponding circuit has already been described in more detail in the above description, and is not described in detail here.

The circuit board of the welding machine of the utility model also adopts an advanced manufacturing process and is ensured by design. The components on the circuit board, whether plug-in electronic components or parts, or a large number of surface mount electronic components on the circuit board, are processed and manufactured by adopting automatic plug-in, automatic surface mount, automatic welding and cleaning modes. Due to the advanced design concept and manufacturing process, the size of the circuit board is smaller. The circuit board and the external devices or parts of the circuit board have few control connecting wires, so the production process of the whole welding machine is simple and convenient to produce. The design and the processing technology can ensure that the production of the product has high production efficiency, and meanwhile, the error rate and the manufacturing cost are low, thereby being beneficial to improving the market competitiveness of the product.

The above is the description of the control process of the welding machine structure and the control circuit part of the utility model. The principle of the circuit is complicated, and the main control idea and result are given above. Because the present invention has given the detailed circuit schematic diagram, it is completely readable for the people who have the circuit reading ability (or have the related circuit knowledge). The circuit diagram is also a silent language. But for those who do not have circuit reading capability (or knowledge of the associated circuit), they are unintelligible even if they have more explanations. For the sake of brevity, this patent specification sets forth only the essential parts of the specification so that the reader of this patent specification will be better able to understand the principles and processes of operation involved. For other controls, one can analyze and understand in conjunction with the circuit diagram.

The above is a detailed description of the present invention in connection with specific welder configurations and circuit boards and control functions, and it should not be construed that the practice of the present invention is limited to these descriptions. It is right other technical personnel in technical field do not deviate from the utility model discloses under the prerequisite of design, can also make a plurality of other deductions and transform, these all should regard as belonging to the utility model discloses the scope of protection.

Claims

1. The utility model provides a microprocessor control pressure regulating transfers no gas protection electric arc welding machine of silk which characterized in that: the main components of the welding machine comprise a shell part, a wire feeding part and a welding machine internal structure and control circuit part;

the wire feeding part mainly comprises a wire feeder and a fixing screw thereof, a welding wire disc shaft and a fixing screw thereof, and a wire feeding control circuit part on a control circuit board; the wire feeder and the wire reel shaft are arranged on the inner middle partition plate, the wire feeder is close to the right front surface of the middle partition plate of the welding machine, and the middle partition plate is provided with corresponding mounting holes; the wire feeder is connected with a welding cable of a welding gun assembly arranged on a front panel of the welding machine; 0.5 or 1Kg of gas-free shielded flux-cored wire is mounted on the wire reel shaft;

the shell part comprises an upper cover plate, a rotating shaft of the upper cover plate, a clamping ring I of the rotating shaft of the upper cover plate, a clamping ring II of the rotating shaft of the upper cover plate, a left side cover plate, a right side cover plate, a U-shaped shell bottom plate, a bottom support leg and a fastening screw thereof, a fastening screw of the side cover plate and a middle partition plate; on the back panel of the bottom plate of the U-shaped casing, the mounted parts are provided with cooling fans and are mounted on the back panel by adopting fixing screws; on the front panel of the U-shaped casing bottom plate, the mounted parts mainly comprise a power switch, a current or wire feed speed adjusting potentiometer and a knob, a voltage adjusting potentiometer and a knob, an overheating protection indicator lamp, a workpiece clamp and a welding cable thereof, a workpiece clamp and a pull-off of a welding cable thereof, a power supply input power wire and a pull-off thereof, a sheath of a welding cable at the rear part of a welding gun, the welding gun and the welding cable thereof, wherein the sheath of the welding cable at the rear part of the welding gun is fixed on the front panel by adopting a fastening nut at the rear part of the welding gun;

the internal structure and control circuit part of the welding machine: the internal structure of the welding machine is divided into two layers by a middle clapboard, and the middle clapboard is fixed on the front panel and the rear panel of the bottom plate of the U-shaped machine shell by screws; the upper layer of the middle partition board is provided with parts of the wire feeding part; a welding transformer is arranged on a bottom plate of the U-shaped machine shell on the lower layer of the middle partition plate, the welding transformer adopts two bottom supports as supports and is fixed on the bottom plate of the U-shaped machine shell by fastening screws; the overheating protector or the temperature controller is arranged on the welding transformer, and the temperature sensing surface of the overheating protector or the temperature controller is arranged to be attached to the surface of a winding lead of the welding transformer; the control circuit board adopts two fixing brackets as supports and is fixed on a bottom plate of a U-shaped shell bottom plate by screws; for the control panel circuit part, the control panel circuit part is connected with a corresponding socket on the circuit board through a plug and a control line thereof, and the control circuit of the welding machine mainly comprises a main circuit, a direct-current power supply circuit, a power grid alternating-current waveform zero crossing point detection or synchronous detection circuit, a current or wire feeding speed and voltage welding parameter setting and detection circuit, a welding gun switching signal detection circuit, a welding output voltage detection and conversion circuit, a welding voltage output and regulation control circuit, a wire feeding control circuit, an overheating protection control and indication circuit part thereof; the welder adopts the bidirectional light-controlled thyristor or the silicon-controlled thyristor and the digital control trigger circuit thereof, and realizes stepless, continuous and wide-range adjustment of welding voltage by utilizing the bidirectional thyristor or the silicon-controlled thyristor which is connected in series in a primary loop of the welding transformer.

2. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the main circuit part consists of a power input switch S1, a common-mode filter inductor T3, a plurality of resistors, a plurality of filter capacitors, a bidirectional thyristor or thyristor Q1 and a welding transformer T2; 220V-240V alternating current passes through a power switch S1, and then is connected with a common mode filter inductor T3, a resistor R301, a resistor R302, a filter capacitor C11, a filter capacitor C13 and a capacitor C29 to form a filter circuit, and after being connected in series with the resistor R301 and the resistor R302, the resistor R301 and the capacitor C29 are connected in parallel at two ends of a common mode filter inductor T3; the filter capacitor C11 and the filter capacitor C13 are respectively connected to two ends of a power line, and the middle connection point of the two capacitors is connected to a frame or a ground end of the welding machine and is connected with a protective grounding wire in a power supply system; the large current path of the bidirectional thyristor or thyristor Q1 is connected in series in the primary loop of the welding transformer T2, and the two ends of the large current path of the bidirectional thyristor or thyristor Q1 and the control electrode thereof are connected with the control circuit; the secondary side of the welding transformer T2 is the output end of the welding machine and is respectively connected with the grounding clamp and the welding cable thereof, and the welding gun and the welding cable thereof.

3. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 2, wherein: the overheating protection control and indication circuit part is connected to a normally-closed overheating protector or temperature controller WKQ through two ends of a socket interface J3, and the overheating protector or temperature controller WKQ is mounted on the winding surface of the welding transformer T2 in a clinging mode; a 2-pin connection resistor R16 of the socket interface J3, and the other end of the resistor R16 is connected with a +15V power supply; a pin 1 of the socket interface J3 is connected with a resistor R18, the other end of the resistor R18 is connected with a pin 13 of the microprocessor U2 and an anode of a diode V3, a cathode of the diode V3 is connected with +5V, and a resistor R19 and a capacitor C8 are connected between the pin 13 of the microprocessor U2 and the ground in parallel; a 16 pin of the microprocessor U2 is connected with the resistor R12, the other end of the resistor R12 is connected with a 1 pin of the socket J4, and a 2 pin of the socket interface J4 is grounded; the pins 1 and 2 of the socket interface J4 are also connected with an overheating protection indicator lamp on the front panel of the welding machine through a plug and a control line thereof, and the anode of the overheating protection indicator lamp is connected with the pin 1 of the socket interface J4; when the overheating phenomenon occurs, the output level of the pin 11 of the microprocessor U2 is utilized to control the light-operated bidirectional thyristor or thyristor U5 and the bidirectional thyristor or thyristor Q1 in the main circuit, so as to realize the control of the no output of the welding machine; the output control signals of pins 19 and 20 of the microprocessor U2 are used for controlling the wire feeding control circuit to stop feeding the wire, thereby achieving the purpose of protecting the welding machine.

4. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the current or wire feeding speed and voltage welding parameter setting and detection circuit part comprises a voltage adjusting potentiometer RP1 and a current or wire feeding speed adjusting potentiometer RP2 on the front panel of the welding machine, which are connected with the control panel part through a plug J2; one fixed ends of a voltage adjusting potentiometer RP1 and a current or wire feeding speed adjusting potentiometer RP2 are grounded, the other fixed ends of the voltage adjusting potentiometer RP1 and the current or wire feeding speed adjusting potentiometer RP2 are respectively connected with a resistor R10 and a resistor R8, the other ends of a resistor R10 and a resistor R8 are connected with +5V, the middle sliding ends of the voltage adjusting potentiometer RP1 and the current or wire feeding speed adjusting potentiometer RP2 are respectively connected with a resistor R11 and a resistor R9, the other end of the resistor R11 is connected with a capacitor C4 and a pin 6 of a microprocessor U2, the other end of the resistor R9 is connected with a capacitor C3 and a pin 5 of a microprocessor U2, and the other ends of the capacitor C3 and a capacitor C4 are grounded; the control system samples the pins 6 and 5 of the microprocessor U2 and performs analog-to-digital conversion, and the microprocessor U2 system can obtain the set values of welding voltage, current or wire feeding speed.

5. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 2, wherein: the power grid alternating current waveform zero crossing point detection or synchronization detection circuit part consists of a power transformer T1, a plurality of diodes, an operational amplifier U1A, a plurality of resistors, a capacitor C1, a capacitor C2 and a diode V1; +15V is used as the working power supply of the circuit part of the operational amplifier U1A; the diode D5, the diode D6, the diode D8 and the diode D9 form a bridge rectifier circuit, the input of the bridge rectifier circuit is connected with the secondary side of the power transformer T1, and the output waveform signal of the bridge rectifier circuit is + VA; the microprocessor U2 control system can obtain the zero crossing point time or the synchronous reference point of the AC waveform of the power grid by detecting the output signal + VA through the 8 pins of the microprocessor U2 control system, and determines the trigger pulse phase or the conduction angle of the bidirectional thyristor or thyristor Q1 in the control main circuit according to the reference point and the given value of the output voltage of the welding machine; one end of the resistor R6 is connected with a signal + VA, the other end of the resistor R6 is connected with the inverting input end of the operational amplifier U1A, and a capacitor C2 and a resistor R7 are connected between the inverting input end and the ground in parallel; a capacitor C1 and a resistor R3 are connected between the non-inverting input terminal of the operational amplifier U1A and the ground in parallel, the non-inverting input terminal is connected with a resistor R1 and a resistor R2, the other end of the resistor R2 is connected with +15V, the other end of the resistor R1 is connected with the output terminal of the operational amplifier U1A, the output terminal is connected with a resistor R5, the other end of the resistor R5 is connected with the resistor R4, the anode of a diode V1 and the 8 feet of the microprocessor U2, the cathode of the diode V1 is connected with +5V, and the other end of the resistor R4 is grounded.

6. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the welding voltage output and regulation control circuit part consists of a microprocessor U2 control system, a light-operated bidirectional thyristor or thyristor U5, a bidirectional thyristor or thyristor Q1, a capacitor C6, a capacitor C10, a plurality of resistors and a piezoresistor FU1 in a main circuit; the pin 11 of the microprocessor U2 is connected with a resistor R13, the other end of the resistor R13 is connected with the anode of a light-emitting diode in a capacitor C6 and a light-operated bidirectional thyristor or thyristor U5, and the cathode of the light-emitting diode and the other end of the capacitor C6 are grounded; a pin 6 in the light-operated bidirectional thyristor or thyristor U5 is connected with a resistor R27, a resistor R22, a resistor R20 and a resistor R21 which are connected in series, the other end of the resistor R21 is connected with a resistor R25 and a capacitor C10, and the other ends of the resistor R25 and the capacitor C10 are respectively connected with two ends of a bidirectional thyristor or thyristor Q1; the two ends of the bidirectional thyristor or thyristor Q1 are connected with the piezoresistor FU1 in parallel.

7. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the welding gun switch signal detection circuit part consists of a socket interface J5, a capacitor C7, a plurality of resistors and a diode V2; the welding gun switch is connected to the socket interface J5 through a plug and a control line thereof; one end of the welding gun switch is connected with the resistor R14, and the other end of the resistor R14 is connected with + 15V; the other end of the welding gun switch is connected with a resistor R15, the other end of a resistor R15 is connected with the anode of a diode V2, a resistor R17, a capacitor C7 and a pin 1 of a microprocessor U2, the other ends of a resistor R17 and a capacitor C7 are grounded, and the cathode of the diode V2 is connected with a +5V power supply; the microprocessor control system can know whether the welding gun switch is closed or not by detecting the 1 pin level state of the U2.

8. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the welding output voltage detection and conversion circuit part consists of a rectifier bridge BD1 and an electrolytic capacitor E1; the input end of the rectifier bridge BD1 is connected in parallel with the secondary output end of the welding transformer T2, and the output end of the rectifier bridge BD1 is connected in parallel with the electrolytic capacitor E1.

9. The non-gas protection arc welder of the microprocessor controlled voltage and wire regulation of claim 1, wherein: the wire feeding control circuit part consists of a socket interface J6, a field-effect tube Q5, a field-effect tube Q6, a plurality of diodes, two NPN type triodes, two PNP type triodes, two operational amplifiers, a plurality of capacitors, a plurality of resistors and an electrolytic capacitor E2; +15V is used as the working power supply of the operational amplifier U3A and operational amplifier U3B circuit; the wire feeding motor is connected to the socket interface J6 through a plug and a control wire thereof; pin 1 of socket interface J6 is positive; the rated voltage of the wire feeding motor is 24V, and the D end of the field effect transistor Q5 is connected to the MVCC + signal end; a pin 1 of the socket interface J6 is connected with an S end of a field effect transistor Q5, a resistor R24, a resistor R34, a resistor R29, a negative polarity end of an electrolytic capacitor E2 and a collector of a PNP type triode Q4; the other end of the resistor R24 is connected with the non-inverting input end of the operational amplifier U3A, a capacitor C20 and a resistor R26 are connected between the non-inverting input end and the ground in parallel, and the inverting input end of the operational amplifier U3A is connected with the output end; the output end of the operational amplifier U3A is connected with a resistor R23, the other end of the resistor R23 is connected with a capacitor C9, a pin 3 of the microprocessor U2 and the anode of a diode V4, the cathode of the diode V4 is connected with +5V, and the other end of the capacitor C9 is grounded; the detection signal obtained by the pin 3 of the microprocessor U2 is a voltage negative feedback signal of the wire feeding motor; the other end of the resistor R29 is connected with the base electrode of the PNP type triode Q4, the collector electrode of the PNP type triode Q2 and the anode of the diode D3, the cathode of the diode D3 is connected with the resistor R33, the other end of the resistor R33 is connected with the emitter electrode of the PNP type triode Q4 and the G end or the control electrode of the field effect transistor Q5; the positive polarity end of the electrolytic capacitor E2 is connected with the cathode of the diode D2, the emitter of the PNP type triode Q2 and the resistor R28, the other end of the resistor R28 is connected with the base of the PNP type triode Q2 and the collector of the NPN type triode Q3, the emitter of the NPN type triode Q3 is connected with the resistor R32, the other end of the resistor R32 is grounded, the base of the NPN type triode Q3 is connected with the resistor R30, and the other end of the resistor R30 is connected with the resistor R31 and the pin 19 of the microprocessor U2; the other end of the resistor R31 is grounded; the other end of the resistor R34 is connected with the D end of the field effect transistor Q6; the S end of the field effect transistor Q6 is connected with the resistor R37, the resistor R40 and the 2 pins of the socket interface J6, and the other end of the resistor R37 is grounded; the G end of the field effect transistor Q6 is connected with a resistor R36, the other end of the resistor R36 is connected with a resistor R35 and a collector of an NPN type triode N1, the other end of the resistor R35 is connected with +15V, an emitter of the NPN type triode N1 is grounded, a base of the NPN type triode N1 is connected with the resistor R41, the other end of the resistor R41 is connected with the resistor R43 and a pin 20 of the microprocessor U2, and the other end of the resistor R43 is connected with + 5V; one end of the resistor R40 is connected with the pin 2 of the socket interface J6, the other end of the resistor R40 is connected with the non-inverting input end of the operational amplifier U3B and the capacitor C16, and the other end of the capacitor C16 is grounded; the inverting input end of the operational amplifier U3B is connected with a resistor R38 and a resistor R39, the other end of the resistor R38 is connected with the output end of the operational amplifier U3B and a resistor R42, and the other end of the resistor R42 is connected with a capacitor C17, the anode of a diode V5 and a pin 2 of a microprocessor U2; the detection signal obtained by pin 2 of the microprocessor U2 is a current feedback signal of the wire feeding motor; the resistor R37 is a current sampling resistor connected in series in the loop of the wire feeding motor; the other end of the capacitor C17 is grounded, and the cathode of the diode V5 is connected with + 5V; the other end of the resistor R39 is connected to ground.