CN100353656C

CN100353656C - Small power spot welding power

Info

Publication number: CN100353656C
Application number: CNB2004100730087A
Authority: CN
Inventors: 马铁军; 杨思乾
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2004-08-19
Filing date: 2004-08-19
Publication date: 2007-12-05
Anticipated expiration: 2024-08-19
Also published as: CN1588777A

Abstract

The present invention discloses a spot welding power supply with small power. An insulated gate bipolar transistor VT1 (hereinafter referred to as IGBT) is electrically connected with an emitting electrode of an IGBT VT2, a collector of the IGBT VT1 is connected with an input terminal A of a circuit, and a collector of the IGBT VT2 is electrically connected with a welding transformer T100 through a filter. A diode VD1 and a voltage dependent resistor RY1 are connected in parallel, and then connected between the collector and the emitting electrode of the IGBT VT1. A diode VD2 and a voltage dependent resistor RY2 are connected in parallel, and then connected between the collector and an emitting electrode of the IGBT VT2. Cathodes of a zener diode VDz1 and a zener diode VDz2 are connected between the emitting electrode and a base electrode of the IGBT VT1 after being connected. Cathodes of a zener diode VDz3 and a zener diode VDz4 are connected between the emitting electrode and a base electrode of the IGBT VT2 after being connected. As the insulated gate bipolar transistor circuit is adopted, the spot welding power supply has high reliability and high and adjustable frequency, directly converts the working frequency alternating current into middle frequency alternating current and high frequency alternating current, and is suitable to weld miniature and ultrathin elements. The circuit is simple, and the manufacturing cost is low.

Description

Small power spot welding power

Technical field

The present invention relates to a kind of small power spot welding power.

Background technology

At present, in the production of products such as battery, electron gun, usually needing does not have the spot welding of splashing to some micro parts, generally do not adopt AC-DC-AC spot welding inverter and there is the spot welding of splashing, promptly the alternating current of 50Hz is become direct current behind over commutation, the alternating current that becomes required frequency through inverter circuit welds again.This inverter mainly has the following disadvantages: do not have current increase and decrement function, so the manufacturability of welding current waveform is relatively poor, welding quality is stable inadequately; The condition of work of inversion device is comparatively abominable, very easily damages, so the reliability of power supply is not high, especially when transforming to high-frequency interchange, the dangerous situation of power supply short circuit can occur, so this power supply generally can only be exported medium frequency alternating current; Power supply must be transformed into the interchange of required frequency more earlier through the full-wave rectifying circuit rectification through inverter circuit, so the circuit complexity, power supply weight, volume are big, the cost height.

Summary of the invention

Must be rectified into direct current by exchanging through full-wave rectifying circuit earlier in order to overcome prior art spot welding inverter, again direct current is transformed into the interchange of required frequency through inverter circuit, and the spot welding inverter does not have current increase and decrement function, can only export medium frequency alternating current, the circuit complexity, the cost height, power supply weight, shortcomings such as volume is big, the invention provides a kind of small power spot welding power, in directly the industrial frequency AC of importing being transformed into, high-frequency ac, and have current increase and a decrement function, circuit is simple, and power supply is in light weight, volume is little, advantage of low manufacturing cost.

The technical solution adopted for the present invention to solve the technical problems is: after the emitter of the emitter of insulated gate bipolar transistor IGBT pipe VT1 and IGBT pipe VT2 is electrically connected, the collector electrode connection circuit input A of IGBT pipe VT1, the collector electrode of IGBT pipe VT2 is electrically connected with filter input end, the output of filter is electrically connected with welding transformer T100, between diode VD1 and the collector electrode and emitter that are connected to IGBT pipe VT1 after piezo-resistance RY1 is in parallel, the anode of diode VD1 connects the emitter of IGBT pipe VT1, and the negative electrode of diode VD1 connects the collector electrode of IGBT pipe VT1; Between diode VD2 and the collector electrode and emitter that are connected to IGBT pipe VT2 after piezo-resistance RY2 is in parallel, the anode of diode VD2 connects the emitter of IGBT pipe VT2, and the negative electrode of diode VD2 connects the collector electrode of IGBT pipe VT2; After linking to each other, the negative electrode of voltage stabilizing didoe VDz1, voltage stabilizing didoe VDz2 is connected between the emitter and base stage of IGBT pipe VT1; After linking to each other, the negative electrode of voltage stabilizing didoe VDz3, voltage stabilizing didoe VDz4 is connected between the emitter and base stage of IGBT pipe VT2.

Described filter is a capacitance-resistance filter, and capacitor C 1 is got 6 μ f, and resistance R 3 is got 3.3K Ω, and resistance R 4 is got 2K Ω.

The present invention's beneficial effect compared to existing technology is: owing to adopted the igbt circuit, can be that middle and high frequency exchanges with the industrial frequency AC Direct Transform of input, make this spot welding power have current increase and decrement function, so welding procedure is good; Copped wave device operating state is safe and reliable, thereby the reliability height of power supply, and this spot welding power can obtain the a-c cycle higher than original technology, is more suitable for welding miniature, ultra-thin; Power supply converts directly to middle and high frequency from industrial frequency AC and exchanges, and circuit is simple, and power supply is in light weight, volume is little, and cost is low.

The present invention is further described below in conjunction with drawings and Examples.

Description of drawings

Fig. 1 is a circuit diagram of the present invention

Fig. 2 is the oscillogram of each point in Fig. 1 circuit, and Fig. 2-a is the oscillogram of 220V input voltage; Fig. 2-b is the oscillogram of networking synchronizing signal; Fig. 2-c is the oscillogram that is added in the control signal on IGBT pipe VT1 break-make control end X1, the Y1; Fig. 2-d is the oscillogram that is added in the control signal on IGBT pipe VT2 break-make control end X2, the Y2; Fig. 2-e is 103 pairs 108 the oscillogram of voltage signal among Fig. 1, i.e. voltage signal after the copped wave; Fig. 2-f is 104 pairs 108 the oscillogram of voltage signal among Fig. 1, the i.e. voltage signal on the former limit of welding transformer T100.

Embodiment

With reference to Fig. 1, the present invention as switching device, adopts the AC/AC converter technique with high-power insulated gate bipolar transistor (hereinafter to be referred as the IGBT pipe), the input AC electricity is carried out copped wave with certain frequency, thereby the alternating current that directly obtains required frequency welds.

Circuit is managed VT1, IGBT pipe VT2 by IGBT, capacitor C 1, resistance R 3, resistance R 4, diode VD1, diode VD2, voltage stabilizing didoe VDz1, voltage stabilizing didoe VDz2, voltage stabilizing didoe VDz3, voltage stabilizing didoe VDz4, piezo-resistance RY1, piezo-resistance RY2 and welding transformer T100 form.After IGBT manages VT1 and the emitter of IGBT pipe VT2 is electrically connected, the collector electrode connection circuit input A of IGBT pipe VT1, the collector electrode of IGBT pipe VT2 is electrically connected with filter input end, and the output of filter is electrically connected with the former limit of welding transformer T100, and filter is that common capacitance-resistance is considered the ripple device; Between diode VD1 and the collector electrode and emitter that are connected to IGBT pipe VT1 after piezo-resistance RY1 is in parallel, the anode of diode VD1 connects the emitter of IGBT pipe VT1, and the negative electrode of diode VD1 connects the collector electrode of IGBT pipe VT1; Between diode VD2 and the collector electrode and emitter that are connected to IGBT pipe VT2 after piezo-resistance RY2 is in parallel, the anode of diode VD2 connects the emitter of IGBT pipe VT2, and the negative electrode of diode VD2 connects the collector electrode of IGBT pipe VT2; Voltage stabilizing didoe VDz1 and the emitter that is connected on IGBT pipe VT1 after the negative electrode of voltage stabilizing didoe VDz2 links to each other with control between the utmost point; Voltage stabilizing didoe VDz3 and the emitter that is connected on IGBT pipe VT2 after the negative electrode of voltage stabilizing didoe VDz4 links to each other with control between the utmost point.

Circuit input end is A, an O end, input 220V alternating current is added in the former limit of welding transformer T100 through IGBT pipe VT1, IGBT pipe VT2 and capacitor C 1, X1, Y1 end and X2, Y2 end are respectively the break-make control end of IGBT pipe VT1 and IGBT pipe VT2, the control utmost point and emitter with IGBT pipe VT1 and IGBT pipe V T2 is electrically connected respectively, control system is sent square-wave signal and be added in X1, Y1 end and X2, Y2 end after being amplified, be the break-make of may command IGBT pipe VT1 and IGBT pipe VT2, just can obtain the alternating voltage waveform of different frequency.The frequency of regulation and control system square-wave signal, make-to-break ratio, the i.e. size of scalable welding energy.

(zero point of Fig. 2-a) is as the synchronizing signal of control system (Fig. 2-b) with input voltage.Add the square wave control signal that upper frequency is 2000Hz (Fig. 2-c) at the positive half cycle of input voltage to break-make control end X1, the Y1 end of IGBT pipe VT1, when control signal is high level, IGBT pipe VT1 conducting, when control signal is low level, IGBT pipe VT1 ends, IGBT pipe VT2 bears back-pressure always and ends electric current process diode VD2 formation loop in this process; Add the square wave control signal that upper frequency is 2000Hz (Fig. 2-d) at the negative half period of input voltage to break-make control end X2, the Y2 end of IGBT pipe VT2, when control signal is high level, IGBT pipe VT2 conducting, when control signal is low level, IGBT pipe VT2 ends, IGBT pipe VT1 bears back-pressure always and ends electric current process diode VD1 formation loop in this process.Like this, in a week of input voltage energising, input voltage is cut into waveform shown in Fig. 2-e.Input voltage is after IGBT pipe VT1 and IGBT pipe VT2 conversion, and it is the voltage of intermediate frequency of 2000Hz that the sine voltage of input has become frequency.

Change the make-and-break signal frequency that IGBT manages VT1 and IGBT pipe VT2 break-make control end by control system, change the output frequency of spot welding power, frequency translation scope of the present invention is 2000Hz～10000Hz.

But can find out that from Fig. 2-e the envelope of voltage waveform substantially still is sinusoidal wave, promptly contain the power frequency component of certain 50Hz in the waveform.This power frequency component can make the conversion efficiency of circuit reduce, the operational characteristic variation, and the power of welding transformer output is reduced, heating is serious, for this reason, inserts the filter circuit of being made up of capacitor C 1, resistance R 3 and resistance R 4 at IGBT pipe VT2 output.After the filtering, the voltage waveform that is added in the former limit of transformer T100 is shown in Fig. 2-f.Get 6 μ f when capacitor C 1, resistance R 3 is got 3.3K, and when resistance R 4 was got 2K, the intermediate frequency power of the 2000Hz of welding transformer T100 output can account for more than 90% of gross power, effectively reduces the harmful effect of power frequency component.

The control utmost point of voltage stabilizing didoe VDz1 and voltage stabilizing didoe VDz2 protection IGBT pipe VT1; the control utmost point of voltage stabilizing didoe VDz3 and voltage stabilizing didoe VDz4 protection IGBT pipe VT2, piezo-resistance RY1 and piezo-resistance RY2 carry out overvoltage protection to IGBT pipe VT1 and IGBT pipe VT2 respectively.

Welding transformer T100 can select middle and high frequency welding transformer for use as required.

Miniature, ultra-thin welding that the present invention is mainly used in, the normal half cycle wave soldering that adopts in the process of miniature, ultra-thin of welding, the electric current of output has current increase, decrement function, can guarantee good welding technological properties.

Claims

1, a kind of small power spot welding power, it is characterized in that: after the emitter of the emitter of insulated gate bipolar transistor IGBT pipe VT1 and IGBT pipe VT2 is electrically connected, the collector electrode connection circuit input A of IGBT pipe VT1, the collector electrode of IGBT pipe VT2 is electrically connected with filter input end, the output of filter is electrically connected with welding transformer T100, between diode VD1 and the collector electrode and emitter that are connected to IGBT pipe VT1 after piezo-resistance RY1 is in parallel, the anode of diode VD1 connects the emitter of IGBT pipe VT1, and the negative electrode of diode VD1 connects the collector electrode of IGBT pipe VT1; Between diode VD2 and the collector electrode and emitter that are connected to IGBT pipe VT2 after piezo-resistance RY2 is in parallel, the anode of diode VD2 connects the emitter of IGBT pipe VT2, and the negative electrode of diode VD2 connects the collector electrode of IGBT pipe VT2; After linking to each other, the negative electrode of voltage stabilizing didoe VDz1, voltage stabilizing didoe VDz2 is connected between the emitter and base stage of IGBT pipe VT1; After linking to each other, the negative electrode of voltage stabilizing didoe VDz3, voltage stabilizing didoe VDz4 is connected between the emitter and base stage of IGBT pipe VT2.

2, small power spot welding power according to claim 1 is characterized in that: described filter is a capacitance-resistance filter, and capacitor C 1 is got 6 μ f, and resistance R 3 is got 3.3K Ω, and resistance R 4 is got 2K Ω.