Alternating current square wave submerged arc welding arc stabilizing circuit

Abstract

An alternating current square wave submerged arc welding arc stabilizing circuit comprises a phase inverter U1, a phase inverter U2, an AND gate U3, an analog switch U4 and a voltage dividing unit. The phase inverter U1 and the phase inverter U2 are respectively connected to a group of IGBT square wave driving signals controlled by alternating current square wave submerged arc welding, and are used for negating the group of IGBT square wave driving signals and then respectively outputting the negated IGBT square wave driving signals to the AND gate U3; the AND gate U3 is connected with the analog switch U4 and is used for carrying out AND on the two paths of negated signals to generate a reversing signal and providing the reversing signal to the analog switch U4; a pin 1 of the analog switch U4 is connected with the voltage dividing unit, the voltage dividing unit is connected between + 5V and the ground, and the analog switch U4 is used for switching a voltage dividing current given signal provided by the voltage dividing unit or providing the normal current given signal to the current driving board according to the reversing signal. According to the circuit, the current is reduced during current reversing of the welding machine, so that the electric arc is more stable, the risk of weld air holes is reduced, the welding quality is improved, only a small number of elements are adopted, and the replacement cost of the whole machine is saved.

Description

Technical Field

[0001] The present application relates to an AC submerged arc welding control technology, and in particular to an AC square wave submerged arc welding arc stabilization circuit. Background Art

[0002] AC square wave submerged arc welding has been widely used in the welding of large workpieces. However, the current changes too much when the current is reversed in traditional AC submerged arc welding, which causes the arc to be violent and increases the risk of weld porosity. If the welding machine equipment is directly replaced with a new one, the above problems can be solved, but it will cause waste of the original equipment and increase the new cost. Therefore, it is necessary to explore a solution that can stabilize the arc by making a small modification on the original equipment. Utility Model Content

[0003] In order to solve the above-mentioned deficiencies of the prior art, the present application provides an AC square wave submerged arc welding arc stabilization circuit, which reduces the current size when the welding machine current is reversed to make the arc more stable, thereby reducing the risk of weld porosity and improving welding quality.

[0004] In order to achieve the above purpose, the utility model adopts the following technologies:

[0005] An AC square wave submerged arc welding arc stabilization circuit comprises an inverter U1, an inverter U2, an AND gate U3, an analog switch U4 and a voltage dividing unit;

[0006] The inverter U1 and the inverter U2 are respectively connected to a group of IGBT square wave drive signals controlled by AC square wave submerged arc welding, and are used to invert a group of IGBT square wave drive signals and output them to the AND gate U3 respectively;

[0007] The AND gate U3 is connected to the analog switch U4, and is used to generate a switching signal after performing AND operation on the two inverted signals and provide it to the analog switch U4;

[0008] Pin 1 of the analog switch U4 is connected to a voltage divider unit, which is connected between +5V and ground, pin 2 of the analog switch U4 is connected to ground, pin 5 is connected to +5V, pin 3 is connected to a normal current given signal, pin 6 is connected to an AND gate U3, and pin 4 is connected to a current drive board of the welding machine. The analog switch U4 is used to switch the voltage divider current given signal provided by the voltage divider unit or the normal current given signal to the current drive board according to the commutation signal.

[0009] The beneficial effects of the utility model are:

[0010] By collecting two signals of the secondary IGBT switch of the traditional AC square wave submerged arc welding control, a current commutation signal is generated through hardware circuits such as reverse and AND. When this commutation signal is high, the current given signal is changed to a fixed small current given signal through an analog switching switch. When the current commutation is completed and this commutation signal is low, the current given signal is changed to the original current given signal through an analog switching switch; thus, without changing the circuit structure of the traditional AC square wave submerged arc welding, only a small number of electronic components are used to improve the arc characteristics of the welding machine and make the weld forming quality more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a circuit schematic diagram of an embodiment of the present application.

[0012] Figure 2 This is an example of a set of IGBT square wave drive signals and commutation signals according to an embodiment of the present application. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings, but the embodiments described in the utility model are only part of the embodiments of the utility model, rather than all the embodiments.

[0014] The present application embodiment provides an AC square wave submerged arc welding arc stabilization circuit, such as Figure 1 As shown, it includes an inverter U1, an inverter U2, an AND gate U3, an analog switch U4 and a voltage divider unit.

[0015] Inverter U1 and inverter U2 are respectively connected to a group of IGBT square wave drive signals controlled by AC square wave submerged arc welding, and are used to invert a group of IGBT square wave drive signals and output them to AND gate U3 respectively. AND gate U3 is connected to analog switch U4, and is used to generate a commutation signal after performing AND operation on the two inverted signals and provide it to analog switch U4.

[0016] Pin 1 of the analog switch U4 is connected to a voltage divider unit, which is connected between +5V and ground, pin 2 of the analog switch U4 is connected to ground, pin 5 is connected to +5V, pin 3 is connected to a normal current given signal, pin 6 is connected to an AND gate U3, and pin 4 is connected to a current drive board of the welding machine. The analog switch U4 is used to switch the voltage divider unit to provide a voltage divider current given signal or the normal current given signal to the current drive board according to the commutation signal. Specifically, the voltage divider unit includes a resistor R26 and a resistor R27, one end of the resistor R26 is connected to +5V, and the other end is connected to one end of the resistor R27 and pin 1 of the analog switch U4, and the other end of the resistor R27 is connected to ground.

[0017] This circuit collects two signals of the conventional AC square wave submerged arc welding control secondary IGBT switch of the existing welding machine, and generates a current commutation signal through hardware circuits such as reverse and AND. Figure 2 As shown, signal A_L and signal A_H are a set of original IGBT square wave drive signals, and high level is effective. After being inverted by inverter U1 and inverter U2, a commutation signal is obtained after passing through AND gate U3.

[0018] When this commutation signal is high, the current setting signal is switched to a small current setting signal after a fixed voltage division through the analog switch U4, and the voltage division is confirmed by setting the resistance values ​​of resistors R26 and R27. When the current commutation is completed and this commutation signal is low, the current setting signal is switched to the original normal current setting signal through the analog switch U4.

[0019] Without changing the circuit structure of traditional AC square wave submerged arc welding, only a small number of electronic components are used to improve the arc characteristics of the welding machine and make the weld forming quality more reliable.

[0020] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application.

Claims

1. An AC square wave submerged arc welding arc stabilization circuit, characterized in that: It includes an inverter U1, an inverter U2, an AND gate U3, an analog switch U4 and a voltage divider unit; The inverter U1 and the inverter U2 are respectively connected to a group of IGBT square wave drive signals controlled by AC square wave submerged arc welding, and are used to invert a group of IGBT square wave drive signals and output them to the AND gate U3 respectively; The AND gate U3 is connected to the analog switch U4, and is used to generate a switching signal after performing AND operation on the two inverted signals and provide it to the analog switch U4; Pin 1 of the analog switch U4 is connected to a voltage divider unit, which is connected between +5V and ground, pin 2 of the analog switch U4 is connected to ground, pin 5 is connected to +5V, pin 3 is connected to a normal current given signal, pin 6 is connected to an AND gate U3, and pin 4 is connected to a current drive board of the welding machine. The analog switch U4 is used to switch the voltage divider current given signal provided by the voltage divider unit or the normal current given signal to the current drive board according to the commutation signal.

2. The AC square wave submerged arc welding arc stabilization circuit according to claim 1, characterized in that: The voltage divider unit includes a resistor R26 and a resistor R27. One end of the resistor R26 is connected to +5V, and the other end is connected to one end of the resistor R27 and pin 1 of the analog switch U4. The other end of the resistor R27 is connected to the ground.

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