Gas shield welding power supply capable of feeding wires at constant speed

Abstract

The utility model discloses a gas shield welding power supply capable of feeding wires at a constant speed, which belongs to the technical field of inverter welding power supplies and comprises a PIC processing module, a motor given sampling module, a D / A conversion module, an actual current sampling module and a current and D / A signal processing module. The PIC processing module is respectively connected with the motor given sampling module, the D / A conversion module, the actual current sampling module and the current and D / A signal processing module; the current and D / A signal processing module is also connected with the D / A conversion module and the actual current sampling module. The circuit is not influenced by the arc length of an electric arc, the current and the voltage are stable, the weld penetration depth is kept consistent under the condition that the distance between a welding gun and a workpiece is continuously changed in the welding process, and the requirement of the welding process of special workpieces is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of inverter welding power supplies, and in particular relates to a gas shielded welding power supply with uniform wire feeding. Background Art

[0002] Gas shielded arc welding is referred to as gas shielded welding or gas electric welding. It is a melting welding that uses an arc as a heat source and gas as a protective medium. Gas shielded welding has the functions and effects of welding firmness, improving production efficiency, reducing costs, improving weld quality, and reducing welding deformation. During the welding process, after the arc voltage increases, the arc power increases, the heat input of the workpiece increases, and the arc length is elongated, and the distribution radius increases, so the penetration depth decreases slightly and the weld width increases. The residual height decreases because the weld width increases, but the amount of wire melt decreases slightly.

[0003] At present, the welding power supplies used in the field of gas shielded welding power supply are basically constant speed wire feeding circuits. As the surface of some workpieces is not very flat or there are special workpieces with irregular shapes, the arc length will be inconsistent between the welding gun and the workpiece surface. The current will also change with the length of the arc, which will directly affect the inconsistency of the depth of welding penetration and cannot meet the requirements of existing welding processes. Utility Model Content

[0004] The utility model provides a gas shielded welding power supply with uniform wire feeding speed, which solves the problem that the distance between the welding gun and the workpiece surface in the existing uniform wire feeding circuit will cause inconsistent arc length, resulting in inconsistent welding penetration depth.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] The utility model provides a gas shielded welding power source with uniform wire feeding, comprising a PIC processing module, a motor given sampling module, a D / A conversion module, an actual current sampling module and a current and D / A signal processing module;

[0007] The PIC processing module is respectively connected to the motor given sampling module, the D / A conversion module, the actual current sampling module and the current and D / A signal processing module; the current and D / A signal processing module is also respectively connected to the D / A conversion module and the actual current sampling module.

[0008] Furthermore, the PIC processing module uses a chip IC1 of model PIC16F1947;

[0009] Pin 17 of the chip IC1 inputs the motor voltage sampling signal; Pin 21, Pin 22 and Pin 23 of the chip IC1 are respectively connected to the D / A conversion module; Pin 24 of the chip IC1 is connected to the motor given sampling module; Pin 27 of the chip IC1 is connected to the actual current sampling module; Pin 30 of the chip IC1 is connected to the current and D / A signal processing module; Pin 10, Pin 19, Pin 26, Pin 38 and Pin 57 of the chip IC1 are all connected to 5V voltage; Pin 9, Pin 20, Pin 25, Pin 41 and Pin 56 of the chip IC1 are grounded.

[0010] Further, the motor given sampling module includes a resistor R32, a grounding resistor R33, a resistor R34, a grounding capacitor C15, an electrolytic capacitor E2 and a diode V7;

[0011] One end of the resistor R32 is connected to the 24th pin of the chip IC1; the other end of the resistor R32 is respectively connected to the grounding resistor R33, the grounding capacitor C15, the positive electrode of the electrolytic capacitor E2, one end of the resistor R34 and the positive electrode of the diode V7; the negative electrode of the electrolytic capacitor E2 is grounded; the other end of the resistor R34 is connected to the motor given input signal; the negative electrode of the diode V7 is connected to the 5V voltage.

[0012] Furthermore, the current and D / A signal processing module uses an amplifier U5B of model TL083;

[0013] The positive input end of the amplifier U5B is connected to the D / A conversion module; the negative input end of the amplifier U5B is respectively connected to one end of the resistor R40, the cathode of the diode V10, the anode of the diode V9, one end of the capacitor C17, one end of the capacitor C18, the grounding capacitor C19, the grounding resistor R42 and one end of the resistor R43; the other end of the resistor R40 is respectively connected to the cathode of the diode V9, one end of the resistor R39, one end of the resistor R38 and the output end of the amplifier U5B; the other end of the resistor R39 is respectively connected to the other end of the capacitor C17 and the other end of the capacitor C18; the anode of the diode V10 is connected to one end of the resistor R41; the other end of R41 is connected to the 30th pin of the chip IC1; the other end of the resistor R43 is connected to the actual current sampling module; the other end of the resistor R38 outputs the motor PWM pulse width control signal.

[0014] Furthermore, the D / A conversion module uses a D / A serial conversion chip U4 of model TLC5615;

[0015] The 1st pin of the chip U4 is connected to the 23rd pin of the chip IC1; the 2nd pin of the chip U4 is connected to the 22nd pin of the chip IC1; the 3rd pin of the chip U4 is connected to the 21st pin of the chip IC1; the 5th pin of the chip U4 is grounded; the 6th pin of the chip U4 is respectively connected to the grounding resistor R18 and one end of the resistor R15; the 7th pin of the chip U4 is connected to one end of the resistor R17; the other end of the resistor R17 is connected to the positive input end of the amplifier U5B; the other end of the resistor R15 is respectively connected to the grounding resistor C9 and the 5V voltage; the 8th pin of the chip U4 is connected to the 5V voltage.

[0016] Furthermore, the actual current sampling module uses an amplifier U5A of model TL083;

[0017] The negative input terminal of the amplifier U5A is respectively connected to the other end of the resistor R43, the output terminal of the amplifier U5A and one end of the resistor R52; the other end of the resistor R52 is connected to the 27th pin of the chip IC1; the positive input terminal of the amplifier U5A is respectively connected to the grounding resistor R53, the grounding capacitor C23 and one end of the resistor R54; the other end of the resistor R54 is connected to the actual current signal; the negative power supply terminal of the amplifier U5A is connected to the -15V voltage; the positive power supply terminal of the amplifier U5A is respectively connected to the +15V voltage and the grounding capacitor C22.

[0018] The beneficial effects of the utility model are as follows: (1) by collecting the motor given input signal, the motor voltage sampling signal and the actual current sampling signal, and performing calculations, a motor PWM pulse width control signal is obtained, and the speed of the wire feeding motor is controlled by the motor PWM pulse width control signal, so that the current and the motor given input value are kept constant, and the voltage and current are stable, which solves the problem that the distance between the welding gun and the workpiece surface in the existing constant speed wire feeding circuit will cause the arc length to be inconsistent, resulting in inconsistent depth of welding penetration;

[0019] (2) The PIC chip improves control accuracy, facilitates function expansion, and can store and call special parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The utility model is a circuit block diagram of a gas shielded welding power source with uniform wire feeding.

[0021] Figure 2 This is a circuit diagram of the PIC processing module of the utility model.

[0022] Figure 3 The circuit diagram of the sampling module of the motor of the utility model is given.

[0023] Figure 4This is a circuit diagram of the current and D / A signal processing module of the utility model.

[0024] Figure 5 This is a circuit diagram of the D / A conversion module of the utility model.

[0025] Figure 6 This is the circuit diagram of the actual current sampling module of the utility model. DETAILED DESCRIPTION

[0026] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical inspirations disclosed in the present invention without departing from the essence of the present invention, and these variations and combinations are still within the protection scope of the present invention.

[0027] Example

[0028] like Figure 1 As shown, the utility model provides a gas shielded welding power supply with uniform wire feeding, including a PIC processing module, a motor given sampling module, a D / A conversion module, an actual current sampling module and a current and D / A signal processing module;

[0029] The PIC processing module is respectively connected to the motor given sampling module, the D / A conversion module, the actual current sampling module and the current and D / A signal processing module; the current and D / A signal processing module is also respectively connected to the D / A conversion module and the actual current sampling module.

[0030] like Figure 2 As shown, the PIC processing module uses a chip IC1 of model PIC16F1947;

[0031] Pin 17 of the chip IC1 inputs the motor voltage sampling signal; Pin 21, Pin 22 and Pin 23 of the chip IC1 are respectively connected to the D / A conversion module; Pin 24 of the chip IC1 is connected to the motor given sampling module; Pin 27 of the chip IC1 is connected to the actual current sampling module; Pin 30 of the chip IC1 is connected to the current and D / A signal processing module; Pin 10, Pin 19, Pin 26, Pin 38 and Pin 57 of the chip IC1 are all connected to 5V voltage; Pin 9, Pin 20, Pin 25, Pin 41 and Pin 56 of the chip IC1 are grounded.

[0032] like Figure 3As shown, the motor given sampling module includes a resistor R32, a grounding resistor R33, a resistor R34, a grounding capacitor C15, an electrolytic capacitor E2 and a diode V7;

[0033] One end of the resistor R32 is connected to the 24th pin of the chip IC1; the other end of the resistor R32 is respectively connected to the grounding resistor R33, the grounding capacitor C15, the positive electrode of the electrolytic capacitor E2, one end of the resistor R34 and the positive electrode of the diode V7; the negative electrode of the electrolytic capacitor E2 is grounded; the other end of the resistor R34 is connected to the motor given input signal; the negative electrode of the diode V7 is connected to the 5V voltage.

[0034] like Figure 4 As shown, the current and D / A signal processing module uses an amplifier U5B of model TL083;

[0035] The positive input end of the amplifier U5B is connected to the D / A conversion module; the negative input end of the amplifier U5B is respectively connected to one end of the resistor R40, the cathode of the diode V10, the anode of the diode V9, one end of the capacitor C17, one end of the capacitor C18, the grounding capacitor C19, the grounding resistor R42 and one end of the resistor R43; the other end of the resistor R40 is respectively connected to the cathode of the diode V9, one end of the resistor R39, one end of the resistor R38 and the output end of the amplifier U5B; the other end of the resistor R39 is respectively connected to the other end of the capacitor C17 and the other end of the capacitor C18; the anode of the diode V10 is connected to one end of the resistor R41; the other end of R41 is connected to the 30th pin of the chip IC1; the other end of the resistor R43 is connected to the actual current sampling module; the other end of the resistor R38 outputs the motor PWM pulse width control signal.

[0036] like Figure 5 As shown, the D / A conversion module adopts a D / A serial conversion chip U4 of model TLC5615;

[0037] The 1st pin of the chip U4 is connected to the 23rd pin of the chip IC1; the 2nd pin of the chip U4 is connected to the 22nd pin of the chip IC1; the 3rd pin of the chip U4 is connected to the 21st pin of the chip IC1; the 5th pin of the chip U4 is grounded; the 6th pin of the chip U4 is respectively connected to the grounding resistor R18 and one end of the resistor R15; the 7th pin of the chip U4 is connected to one end of the resistor R17; the other end of the resistor R17 is connected to the positive input end of the amplifier U5B; the other end of the resistor R15 is respectively connected to the grounding resistor C9 and the 5V voltage; the 8th pin of the chip U4 is connected to the 5V voltage.

[0038] like Figure 6As shown, the actual current sampling module adopts an amplifier U5A of model TL083;

[0039] The negative input terminal of the amplifier U5A is respectively connected to the other end of the resistor R43, the output terminal of the amplifier U5A and one end of the resistor R52; the other end of the resistor R52 is connected to the 27th pin of the chip IC1; the positive input terminal of the amplifier U5A is respectively connected to the grounding resistor R53, the grounding capacitor C23 and one end of the resistor R54; the other end of the resistor R54 is connected to the actual current signal; the negative power supply terminal of the amplifier U5A is connected to the -15V voltage; the positive power supply terminal of the amplifier U5A is respectively connected to the +15V voltage and the grounding capacitor C22.

[0040] The working principle of the utility model is as follows: a motor given input signal is collected through a motor given sampling module and input into a PIC processing module, a motor voltage sampling signal is input into the PIC processing module at the same time, an actual current sampling module samples the actual current signal, and the sampled current signal is input into the PIC module, the collected motor given input signal, the motor voltage sampling signal and the actual circuit signal are converted through a D / A conversion module, the converted signal is input into a current and D / A signal processing module for calculation, and a motor PWM pulse width control signal is obtained, and finally the speed of the wire feeding motor is controlled through the motor PWM pulse width control signal.

[0041] In this embodiment, when the arc becomes longer, the actual current will become smaller, which is inconsistent with the given input of the motor. The current signal returned by the actual current sampling is calculated with the given input value of the motor, and the output motor control PWM pulse width control signal will become larger, so that the pulse width of the motor PWM control will become wider, and the speed of the wire feeding motor will become faster at a uniform speed. When the current signal returned by the actual current sampling is equal to the given input value of the motor, the PWM pulse width stops widening and the speed of the wire feeding motor stops increasing, and the current and the given input value of the motor are maintained at a constant value.

[0042] When the arc length becomes shorter, the current will become larger, which is inconsistent with the motor input given value. The current signal returned by actual current sampling is calculated with the motor given value, and the output motor control signal data will become smaller, and the pulse width of the motor PWM control will become narrower, and the wire feeding motor speed will slow down uniformly. When the current signal returned by actual current sampling is equal to the motor given input value, the PWM pulse width stops narrowing, and the wire feeding motor speed stops slowing down, maintaining a constant value of the current and the motor given input value.

[0043] Therefore, the circuit of the utility model has stable current and voltage, and can keep the weld penetration consistent even when the distance between the welding gun and the workpiece changes during the welding process of special workpieces, thereby greatly improving the process control and meeting the requirements of the welding process of special workpieces. The successful development of the power supply will be widely used in the machinery, aviation, chemical, petroleum, electric power and automobile industries, and the market demand is huge.

Claims

1. A gas shielded welding power source with uniform wire feeding, characterized in that: It includes PIC processing module, motor given sampling module, D / A conversion module, actual current sampling module and current and D / A signal processing module; The PIC processing module is respectively connected to the motor given sampling module, the D / A conversion module, the actual current sampling module and the current and D / A signal processing module; the current and D / A signal processing module is also respectively connected to the D / A conversion module and the actual current sampling module.

2. The gas shielded welding power source with uniform wire feeding according to claim 1, characterized in that: The PIC processing module uses a chip IC1 of model PIC16F1947; Pin 17 of the chip IC1 inputs the motor voltage sampling signal; Pin 21, Pin 22 and Pin 23 of the chip IC1 are respectively connected to the D / A conversion module; Pin 24 of the chip IC1 is connected to the motor given sampling module; Pin 27 of the chip IC1 is connected to the actual current sampling module; Pin 30 of the chip IC1 is connected to the current and D / A signal processing module; Pin 10, Pin 19, Pin 26, Pin 38 and Pin 57 of the chip IC1 are all connected to 5V voltage; Pin 9, Pin 20, Pin 25, Pin 41 and Pin 56 of the chip IC1 are grounded.

3. The gas shielded welding power source with uniform wire feeding according to claim 2, characterized in that: The motor given sampling module includes a resistor R32, a grounding resistor R33, a resistor R34, a grounding capacitor C15, an electrolytic capacitor E2 and a diode V7; One end of the resistor R32 is connected to the 24th pin of the chip IC1; the other end of the resistor R32 is respectively connected to the grounding resistor R33, the grounding capacitor C15, the positive electrode of the electrolytic capacitor E2, one end of the resistor R34 and the positive electrode of the diode V7; the negative electrode of the electrolytic capacitor E2 is grounded; the other end of the resistor R34 is connected to the motor given input signal; the negative electrode of the diode V7 is connected to the 5V voltage.

4. The gas shielded welding power source with uniform wire feeding according to claim 2, characterized in that: The current and D / A signal processing module uses an amplifier U5B of model TL083; The positive input end of the amplifier U5B is connected to the D / A conversion module; the negative input end of the amplifier U5B is respectively connected to one end of the resistor R40, the cathode of the diode V10, the anode of the diode V9, one end of the capacitor C17, one end of the capacitor C18, the grounding capacitor C19, the grounding resistor R42 and one end of the resistor R43; the other end of the resistor R40 is respectively connected to the cathode of the diode V9, one end of the resistor R39, one end of the resistor R38 and the output end of the amplifier U5B; the other end of the resistor R39 is respectively connected to the other end of the capacitor C17 and the other end of the capacitor C18; the anode of the diode V10 is connected to one end of the resistor R41; the other end of R41 is connected to the 30th pin of the chip IC1; the other end of the resistor R43 is connected to the actual current sampling module; the other end of the resistor R38 outputs the motor PWM pulse width control signal.

5. The gas shielded welding power source with uniform wire feeding according to claim 3 is characterized in that: The D / A conversion module uses a D / A serial conversion chip U4 of model TLC5615; The 1st pin of the chip U4 is connected to the 23rd pin of the chip IC1; the 2nd pin of the chip U4 is connected to the 22nd pin of the chip IC1; the 3rd pin of the chip U4 is connected to the 21st pin of the chip IC1; the 5th pin of the chip U4 is grounded; the 6th pin of the chip U4 is respectively connected to the grounding resistor R18 and one end of the resistor R15; the 7th pin of the chip U4 is connected to one end of the resistor R17; the other end of the resistor R17 is connected to the positive input end of the amplifier U5B; the other end of the resistor R15 is respectively connected to the grounding resistor C9 and the 5V voltage; the 8th pin of the chip U4 is connected to the 5V voltage.

6. The gas shielded welding power source with uniform wire feeding according to claim 3, characterized in that: The actual current sampling module uses an amplifier U5A of model TL083; The negative input terminal of the amplifier U5A is respectively connected to the other end of the resistor R43, the output terminal of the amplifier U5A and one end of the resistor R52; the other end of the resistor R52 is connected to the 27th pin of the chip IC1; the positive input terminal of the amplifier U5A is respectively connected to the grounding resistor R53, the grounding capacitor C23 and one end of the resistor R54; the other end of the resistor R54 is connected to the actual current signal; the negative power supply terminal of the amplifier U5A is connected to the -15V voltage; the positive power supply terminal of the amplifier U5A is respectively connected to the +15V voltage and the grounding capacitor C22.

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