CN2201206Y - Frequency-change voltage-regulation squarewave a.c. arc welding power source - Google Patents

Abstract

The utility model relates to a frequency-change voltage-regulation square-wave arc welding power. An input terminal of an inverter is connected with an output terminal of a direct current power supply, while an output terminal of the inverter is connected with a primary coil of a potential transformer. A base electrode of a switching tube T1 of the inverter, an emitter electrode of the switching tube T1 and a joint point of a collecting electrode of a switching tube T4 are connected with a driver D 1. A base electrode and an emitter electrode of a switching tube T2 are connected with the driver D2. A base electrode of a switching tube T3, an emitter electrode of the switching tube T3 and a joint point of the collecting electrode of the switching tube T2 are connected with driver D3; a base electrode and an emitter electrode of a switching tube T4 are connected with a driver D4; the drivers D1-D4 are connected with a frequency-modulator. The utility model enhances arc striking performance and arc stabilizing performance, and has wide adaptability.

Description

Frequency-change voltage-regulation squarewave a.c. arc welding power source

The utility model relates to a kind of Arc Welding Power, especially refers to extensively be suitable for the square wave alternating-current Arc Welding Power of various arc-welding.

At present, though common ac arc wedling machine low cost of manufacture, weld strength is low, narrow application range; With the silicon rectifier welder is the DC arc welder of representative, weld strength height but manufacturing cost is also high, and in above-mentioned two kinds of arc-welding machines, the structure of regulating output voltage is also complicated simultaneously.In the last few years, appearance connects inverter 2 with arc welding transformer 1 output, and the square wave alternating-current Arc Welding Power of output square wave alternating-current voltage, directly connect arc welding and carry out arc-welding (as shown in Figure 1) to 4, its output voltage, the electric current commutating speed is fast, have good striking and stabilising arc performance, but, because the semiconductor devices (but as self-on-off switching tube) in the inverter 2 is not isolated with welding arc, influence the reliability service of semiconductor devices, the output AC square wave can produce distortion, inverter 2 is in the low-voltage output of transformer 1 again, and semiconductor devices (but as self-on-off switching tube) capacity requirement is big, thereby cost improves, the adjustment of output voltage simultaneously is by changing transformer 1 magnetic core or loop construction, complex structure, heavy.

In view of this, the purpose of this utility model provides a kind of frequency conversion voltage adjusting square wave alternating-current Arc Welding Power, produces square-wave voltage by inverter, connects the arc welding handle through transformer output again, and regulates output voltage to regulate square wave alternating-current electricity frequency mode.

But the purpose of this utility model is achieved in that a kind of frequency conversion voltage adjusting square wave alternating-current Arc Welding Power and comprises mainly by self-on-off switching tube T ₁, T ₂, T ₃And T ₄Inverter and the frequency modulator formed is characterized in that: the input of inverter connects dc power output end, and its output connects transformer; But the self-on-off switching tube T of inverter ₁But base stage self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄The colelctor electrode tie point connects driver D ₁But, self-on-off switching tube T ₂Base stage is connected driver D with emitter stage ₂But, self-on-off switching tube T ₃But base stage self-on-off switching tube T ₃But emitter stage is connected driver D with self-on-off switching tube T2 colelctor electrode tie point ₃But, self-on-off switching tube T ₄Base stage is connected driver D with emitter stage ₄, driver D ₁, D ₂, D ₃And D ₄All connect frequency modulator again.

But the input of above-mentioned inverter is self-on-off switching tube T ₁But colelctor electrode and self-on-off switching tube T ₄Emitter stage; But above-mentioned inverter output end is self-on-off switching tube T ₃But emitter stage and self-on-off switching tube T ₂Colelctor electrode tie point, but self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄The colelctor electrode tie point.

Owing to adopt such scheme: improve striking and stabilising arc performance, simple in structure, cost reduces, and applicability is wide.

Below in conjunction with drawings and Examples the utility model is further specified.

The schematic block circuit diagram of Fig. 1 prior art.

Fig. 2 the utility model exemplary embodiments circuit theory diagrams.

Among the figure: 1, transformer (common transformer or arc welding transformer) 2, inverter T ₁, T ₂, T ₃And T ₄But self-on-off switching tube 3, frequency modulator D ₁, D ₂, D ₃And D ₄Driver P ₁, P ₂, P ₃And P ₄Pulse output end 4, arc welding handle

As shown in Figure 2, present embodiment mainly comprises inverter 2 and frequency modulator 3.

But inverter 2 is by self-on-off switching tube T ₁, T ₂, T ₃And T ₄Be formed by connecting, but and self-on-off switching tube T ₁And T ₂Series connection, but self-on-off switching tube T ₂And T ₃Series connection receives the direct current of input, and can export the square wave alternating-current electricity, belongs to prior art; The input of this inverter 2 (but self-on-off switching tube T ₁But colelctor electrode self-on-off switching tube T ₄Emitter stage) connect the positive and negative electrode (or with alternating current in the electrical network, through rectification, filtering) of dc source respectively, and output (but self-on-off switching tube T ₃But emitter stage and self-on-off switching tube T ₂Colelctor electrode tie point c, but self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄Colelctor electrode tie point d) connect common transformer 1 primary coil b end and a end (also can be connected on the arc welding transformer primary coil of common arc-welding machine certainly), then transformer 1 secondary coil connects arc welding 4 through inductance coil.

Frequency modulator (PFM) 3, the normal model that adopts: 555 time base circuits belong to prior art; The pulse output end P that wherein sends ₁, P ₂, P ₃And P ₄Connect driver D respectively ₁, D ₂, D ₃And D ₄(model: M57958L), and driver D ₁But output connects self-on-off switching tube T ₁Base stage, but self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄Colelctor electrode tie point d, driver D ₂But output connects self-on-off switching tube T ₂Base stage and emitter stage, driver D ₃But output connects self-on-off switching tube T ₃Base stage, but self-on-off switching tube T ₃But emitter stage and self-on-off switching tube T ₂Colelctor electrode tie point c, driver D ₄But output connects self-on-off switching tube T ₄Base stage and emitter stage; This frequency modulator 3 is at pulse output end P ₁, P ₂, P ₃And P ₄Alternately send pulse, regulate the mode of square wave alternating-current frequency, change transformer 1 leakage reactance or output reactance, thereby regulate output voltage, to obtain desirable output external characteristic, its principle is: the output external characteristic of ac arc wedling machine is:

$U_a=\sqrt{{\mathrm{Uo}}^2-{\left(6.28\mathrm{fLIa}\right)}^2}$ （1）

Ua-arc voltage Ia-arc current

Uo-AC welding set floating voltage f-frequency

L-ac arc wedling machine equivalence outputting inductance (leakage inductance)

As seen, frequency f one regularly, its output characteristics is an ellipse garden curve in the I quadrant, regulating frequency f can regulate its output external characteristic, and not only reliably but also simple to operate.

The process of present embodiment output square wave alternating-current electricity is as follows:

Pulse output end P when frequency modulator 3 ₁, P ₂Send pulse, but self-on-off switching tube T ₁, T ₂Conducting, transformer 1 primary coil a holds to the b termination logical; As pulse output end P ₁, P ₂Turn-off (pulse disappearance), simultaneously pulse output end P ₃, P ₄Send pulse, but self-on-off switching tube T ₃, T ₄Conducting, transformer 1 primary coil b holds to a termination logical.

In sum, the utility model is because the output current zero-crossing timing is extremely lacked (＜50 microsecond), voltage, electric current turning velocity are exceedingly fast, when being used for manual electric arc welding and argon tungsten-arc welding, power supply can be at any time ignites and ignitor supply again for electric arc provides needed, have fabulous striking and stabilising arc performance, therefore can be used for the manual metal-arc welding of acidic electrode and basic electrode; The argon tungsten-arc welding of aluminium, magnesium and alloy thereof does not have the arc blow phenomenon during welding; Regulate the output electricity not only reliably but also simple to operate; Cost reduces greatly, applicability is wide, in addition, the utility model output is (lower than arc welding transformer cost) except that can connecting the common transformer secondary coil, also can directly connect common arc-welding machine (arc welding transformer wherein) is used and (gives full play to the effect of existing common electrical arc-welding machine, enlarge the scope of application, widen 10 times of existing common electrical arc-welding machine zones of welding current).

Claims (2)

1, but a kind of frequency conversion voltage adjusting square wave alternating-current Arc Welding Power comprises mainly by self-on-off switching tube T ₁, T ₂, T ₃And T ₄Inverter and the frequency modulator formed is characterized in that: the input of inverter connects dc power output end, and its output connects transformer; But the self-on-off switching tube T of inverter ₁But base stage self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄The colelctor electrode tie point connects driver D ₁But, self-on-off switching tube T ₂Base stage is connected driver D with emitter stage ₂But, self-on-off switching tube T ₃But base stage self-on-off switching tube T ₃But emitter stage and self-on-off switching tube T ₂The colelctor electrode tie point connects driver D ₃But, self-on-off switching tube T ₄Base stage is connected driver D with emitter stage ₄, driver D ₁, D ₂, D ₃And D ₄All connect frequency modulator again.

2, by the described frequency conversion voltage adjusting square wave alternating-current of claim 1 Arc Welding Power, it is characterized in that: but the input of above-mentioned inverter is self-on-off switching tube T ₁But colelctor electrode and self-on-off switching tube T ₄Emitter stage; But above-mentioned inverter output end is self-on-off switching tube T ₃But emitter stage and self-on-off switching tube T ₂Colelctor electrode tie point, but self-on-off switching tube T ₁But emitter stage and self-on-off switching tube T ₄The colelctor electrode tie point.

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