KR20200102880A - Inverter type argon gas welding apparatus - Google Patents

Abstract

The present invention relates to an inverter-type argon gas welding machine and, more specifically, to an inverter-type argon gas welding machine having low power consumption. According to the present invention, the inverter-type argon gas welding machine comprises: a main body; a welding torch connected to the main body; a welding electrode; and a three-phase inverter-type current supply unit, wherein the three-phase inverter-type current supply unit includes a first rectifying unit, a first smoothing unit, a first inverter unit, a second rectifying unit, a second smoothing unit, and a second inverter unit.

Description

Inverter type argon gas welding machine {INVERTER TYPE ARGON GAS WELDING APPARATUS}

The present invention relates to an argon gas welding machine that injects argon gas, which is one of inert gases, onto a welding area and at the same time provides a high current between a material to be welded and an electrode rod installed in a welding torch to dissolve the welding rod. .

In general, welding is a method of making two or more materials to be welded (base metal) in a molten or semi-melted state and joining them by putting a filler material such as a welding rod, and various welding methods are used depending on the type and thickness of the material.

Among these welding methods, gas arc welding uses gases such as carbon dioxide and argon as a protective gas and generates an arc with an electrode so that welding is performed by melting the welding rod and the material to be welded with arc heat. Inert gas) welding and MAG (Metal Active Gas) welding.

Among these MIG (Metal Inert Gas) welding, argon gas welding dissolves the welding target by dissolving the welding rod by injecting argon gas to the welding area and providing current between the welding material (base material) and the electrode installed in the welding torch. This is the way to do it. Since argon gas used for argon gas welding is an inert gas that is stable even at high temperatures, it blocks air at the welding site to prevent oxidation.

Electrodes used for argon gas welding are divided into a consumable electrode that fills the joint by dissolving the electrode itself, a welding electrode, and a non-consumable electrode that dissolves and bonds a separate electrode from the electrode without melting the electrode.

The method of using tungsten among these consumable electrodes is called TIG (Tungsten Inert Gas) arc welding. Tig welding is a welding in which heat is generated by the arc by generating an arc between the tungsten electrode and the material to be welded in an atmosphere of argon gas, which is an inert gas, thereby melting the material to be welded and the electrode to join the material to be welded. That's the way.

As an example of such a TIG welding machine, Korean Patent Laid-Open No. 10-1989-0007831 (published on Jul. 6, 1989) discloses a base material to be welded, a non-consumable electrode disposed to face the base material at a predetermined interval, and the base material. A non-consumable electrode disposed to face each other, an alternating current arc welding power source connected between the base material and the non-consumable electrode, and an additional wire supplied toward an arc generator formed between the base material and the non-consumable electrode; , A wire supply means for supplying the added wire, and a wire heating power supply that energizes the added wire, and the wire heating power supply is a pulse synchronized with the phase of the AC arc current formed between the non-consumable electrode and the base material. A current is flowed through the added wire to heat it, and a pulsed wire heating current flows through the added wire during a period in which the non-consuming electrode becomes a cathode by an AC arc formed between the non-consumable electrode and the base material. Heating, and stopping the wire heating current during the period in which the non-consuming electrode becomes the anode by the alternating current arc, or by allowing a small current to flow through the added wire so as not to substantially generate magnetic blow to heat it. An alternating current tig welding apparatus using a hot wire, characterized in that it has been disclosed, is disclosed.

In general, the AC power source is 50 to 60 Hz single-phase power source through a transformer to induce the same 50 to 60 Hz welding power source as the main power source from the secondary side. The alternating current welding machine controls the welding current by operating a thyristor to adjust the current waveform. The welding current is amplified as it passes through the transformer and is induced into a large current capable of welding.

In recent years, DC TIG welding machines are in the spotlight, because of the miniaturization and cost reduction of power elements required for inverter configurations such as IGBTs and diodes, reducing the manufacturing cost required to manufacture DC argon gas welding machines, and the reliability of each element. This is because it has been improved. In addition, compared to the AC Tig Welding Machine, the DC Tig Welding Machine can be controlled in detail.

The current control of the AC TIG welding machine widely used in the industrial field uses the phase control of a thyristor, so it is possible to control 120 times per second. The AC TIG welding machine cannot cope with the change in dynamic resistance in a short welding process, and the instantaneous heat input is large, so a lot of spatter is generated. The generated spatter has disadvantages of deteriorating welding quality and causing contamination around the welding part.

On the other hand, since DC Tig welding is controlled by 1kHz PWM (Pulse Width Modulation), it is possible to control 2000 times per second. Therefore, the DC Tig Welding Machine has the advantage of overcoming the disadvantages of the AC TIG Welding Machine through precise control and saving energy by suppressing the current loss.

As an example of such a DC TIG welding machine, Korean Utility Model Registration No. 20-0172028 (Announcement on March 15, 2000) has a plurality of suction holes vertically skewed at the bottom and a front channel for selecting and selecting various welding parameters at the top. A case consisting of a front plate vertically fixed to one end of a flat lower plate by each of the switch units, and a rear plate vertically fixed to the other end of the lower plate to have a discharge hole; In the part arrangement structure of a tig welding machine comprising a cooling fan installed on the rear plate to suck in external cold air through the suction hole and then discharge it through the discharge hole, it is close to the suction hole of the front plate. A radiator in which a main transformer that outputs a large current of a low voltage and a reactor that smoothes an electric component with a DC component are sequentially stacked and arranged on the lower plate inside the case, and a plurality of vortex holes are formed on the lower plate between the cooling fan and the main transformer. A shielding plate that is spaced apart using a plurality of support pieces and blocks noise or high temperature heat generated from the main transformer and reactor extend from the inside of the front plate to partially adhere to the side of the radiator. Arranged in a shape, and on the radiator from the cooling fan to the shield plate, an input diode converting AC input power into DC input power and IGBT converting DC low voltage high current output power into AC 50 kHz pulse wave The main circuit board is arranged on the input diode and the IGBT, and on the input diode and the IGBT, a main circuit board implementing a main controller unit that calculates and processes a welding parameter selected by operation of the front channel switch unit to output an optimum desired welding voltage and a desired welding current is provided. A PWM circuit board that implements a PWM (Pulse Width Modulation) control unit that controls the IGBT so that it is closely fixed to the rear plate and is spaced apart from the radiator at the same time and outputs a uniform output current on the shielding plate. A component arrangement structure of a tig welding machine fixedly disposed on an inner surface of the front plate so as to be spaced apart parallel to the main circuit board is disclosed.

However, in the case of the conventional DC inverter type TIG welding machine as described above, only DC current is finally output, so that only DC argon gas welding is possible. In addition, in the case of the conventional DC inverter type TIG welding machine as described above, there is a problem in that the peak reaching time is long and the required power is large.

1. Korean Patent Publication No. 10-1989-0007831 (published on July 6, 1989) 2. Republic of Korea Utility Model Registration No. 20-0172028 (announced on March 15, 2000)

Accordingly, the present invention has been conceived to solve the problems of the prior art, and is based on the problem of providing an inverter type argon gas welding machine capable of direct current argon gas welding or alternating current argon gas welding according to the user's selection.

In addition, the present invention is based on the problem of providing an inverter type argon gas welding machine having a short peak arrival time and a low power requirement.

The object of the present invention described above is a main body, a welding torch connected to the main body and provided with an electrode therein, a welding electrode connected to the main body and connected to a material to be welded, and the welding torch installed in the main body. And a three-phase inverter-type current supply unit for applying a current for welding to an electrode and the welding electrode, wherein the three-phase inverter-type current supply unit comprises: a first rectifier for rectifying an AC current input to the three-phase into a DC current And, a first smoothing unit for smoothing the DC current output from the first rectifying unit, a first inverter unit for converting the DC current smoothed by the first smoothing unit into a variable high-frequency AC current, and in the first inverter unit A transformer part transforming the output AC current into a low voltage high current suitable for welding, a second rectifying part converting the AC current output through the trans part into a DC voltage by rectifying again, and the DC current output from the second rectifying part are smoothed. A second smoothing unit that converts the DC current passing through the second smoothing unit into a variable high-frequency AC current and provides a high-frequency alternating current or direct current to the electrode of the welding torch and the welding electrode depending on whether or not it is operated. And, a microprocessor for controlling the entire operation of the three-phase inverter type current supply unit, and a mode selection switch for controlling the operation of the second inverter unit by providing a switching signal to the microprocessor while a switching operation is operated according to a user's selection. It is achieved by providing a three-phase inverter type argon gas welding machine comprising a.

According to a preferred feature of the present invention, the first rectifying part is formed of a Zener diode, and the second rectifying part is formed of a full-wave rectifying bridge circuit including four diodes.

According to a preferred feature of the present invention, the first inverter unit includes four insulated gate type bipolar transistors (IGBTs) arranged in a full-bridge form to vary the DC current smoothed in the first smoothing unit through two alternating switching. The second inverter unit converts the DC current smoothed by the second smoothing unit into a variable high-frequency alternating current through alternating switching once two insulated gate type bipolar transistors (IGBT) are arranged in parallel.

According to the inverter type argon gas welding machine according to the present invention, AC argon gas welding is possible during operation of the second inverter unit as the operation of the second inverter unit is controlled by the microprocessor according to the switching operation of the mode selection switch. When the inverter is not in operation, there is an advantage that direct argon gas welding is possible.

In addition, according to the inverter type argon gas welding machine according to the present invention, when AC argon gas welding is performed during the operation of the second inverter unit, the peak arrival time is short and the power required is low.

1 is a perspective view of an inverter type argon gas welding machine according to an embodiment of the present invention.
2 is a circuit diagram of a three-phase inverter type current supply unit in the inverter type argon gas welding machine according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this is for explaining in detail enough that a person of ordinary skill in the art can easily carry out the invention, and this does not mean that the technical spirit and scope of the present invention are limited.

1 is an overall structural diagram of an inverter type argon gas welding machine according to an embodiment of the present invention.

The inverter type argon gas welding machine 1 according to an embodiment of the present invention provides argon gas to the welding area and at the same time provides a high current between the electrode of the welding torch 20 and the welding electrode 30 to form a welding rod (not shown). As an apparatus for welding a material to be welded by melting, as shown in FIG. 1, a body 10, a welding torch 20 connected to the body 10 and provided with electrodes therein, and the body 10 A three-phase inverter type current supply unit that is connected and connected to the material to be welded, and is installed in the body 40 and applies a current for welding to the electrodes of the welding torch 20 and the welding electrode 30 It includes (40).

Here, the main body 10 is to form the body frame of the inverter type argon gas welding machine 1 according to an embodiment of the present invention, the electrode of the welding torch 20, the welding electrode 30 and the three-phase inverter type current It forms the installation frame of the supply unit 40.

The welding torch 20 is electrically connected and fixed to the front and lower sides of the above-described main body 10. An electrode is provided in the welding torch 20, and the electrode of the welding torch 20 forms a welding electrode for welding the material to be welded together with the welding electrode 30, and itself may form a welding rod. , Can be formed separately from the welding rod.

The welding electrode 30 is also electrically connected to the front and lower sides of the above-described main body 10. The welding electrode 30 is to allow a welding current to flow through the material to be welded in contact with the material to be welded, and a connecting member in the form of tongs or a fastening plate is provided at an end thereof.

The above-described main body 10, the welding torch 20 with electrodes, and the welding electrode 30 are the same as the configuration of a conventional argon gas welding machine which is one of MIG (Metal Inert Gas) welding machines, so the specification is simplified here. Further detailed descriptions for this will be omitted.

In addition, a three-phase inverter type current supply unit 40 for applying a welding current is installed in the body 40 described above. It serves to apply a current for welding to the electrode of the welding torch 20 and the welding electrode 30 by receiving the three-phase AC current of the three-phase inverter type current supply unit 40. The circuit diagram of the inverter type current supply unit is shown.

As shown in FIG. 2, the three-phase inverter type current supply unit 40 includes a first rectifying unit 41 for rectifying an AC current input to the three phases into a DC current, and output from the first rectifying unit 41. A first smoothing unit 42 for smoothing a DC current, a first inverter unit 43 for converting the DC current smoothed by the first smoothing unit 42 into a variable high-frequency AC current, and a first inverter unit 43 A transformer unit 44 that transforms the AC current output from the AC current into a low voltage high current suitable for welding, a second rectifying unit 45 that rectifies the AC current output through the transformer unit 44 to convert it into a DC voltage, and 2 The second smoothing unit 46 smoothing the DC current output from the rectifying unit 45 and the DC current passed through the second smoothing unit 46 are converted into variable high-frequency AC current, and the welding torch 20 is operated depending on whether or not it is operated. A second inverter unit 47 that provides a high-frequency alternating current or direct current to the electrodes and welding electrodes 30 of, and a microprocessor 48 that controls the entire operation of the three-phase inverter type current supply unit 40, It includes a mode selection switch 49 for controlling the operation of the second inverter unit 47 by providing a switching signal to the microprocessor 48 while a switching operation is performed according to a user's selection.

Here, the first rectifying unit 41 rectifies the AC current input in the three phases with a DC current, and is preferably formed of a Zener diode.

Zener diode is a type of diode, also referred to as a constant voltage diode, and is a device used to obtain a constant voltage. Zener diodes have the same characteristics as normal diodes in the forward direction, but when voltage is applied in the reverse direction, a reverse current flows at a specific voltage (breakdown voltage or zener voltage) lower than that of a normal diode. Zener diodes are designed to significantly lower the breakdown voltage for the purpose of obtaining a constant voltage, and are often used to construct a constant voltage source for stabilizing a voltage supplied to an electric circuit. In addition, the first rectifying part 41 may be formed of a full-wave rectifying bridge circuit including four diodes according to an embodiment.

The first smoothing unit 42 may be implemented as a smoothing capacitor connected in parallel to the output of the first rectifying unit 41 in order to rectify or detect the pulsating DC current output from the first rectifying unit 41 and output it as a DC current. .

The first inverter unit 43 converts the DC current smoothed by the first smoothing unit 42 into a variable high-frequency alternating current, and four insulated gate type bipolar transistors (IGBT) are arranged in a full-bridge form to alternate two times. It can be implemented in the form of converting the DC current smoothed by the first smoothing unit 42 into a variable high-frequency AC current through switching.

The insulated gate type bipolar transistor (IGBT) is a kind of power semiconductor for high power switching. The switching function that blocks or allows the flow of electricity can be implemented with other parts or circuits, but the more precise operation is required, the faster the operation speed and the less power loss, the more dedicated parts are required. The insulated gate type bipolar transistor (IGBT) is a power switching semiconductor that complements the disadvantages and combines the advantages of low-power, high-speed, and expensive MOSFETs with transistors, which are conventional switching semiconductors that have a complex circuit configuration and slow operation speed instead of low cost. .

The transformer unit 44 can be implemented as an AC transformer that transforms an AC current into a low voltage high current suitable for welding using an electromagnetic induction phenomenon.

The second rectifying unit 45 rectifies the AC current output through the transformer unit 44 and converts it into a DC voltage, and can be implemented as a full-wave rectifying bridge circuit of a known structure including four diodes. In addition, the second rectifying unit 45 may be implemented as a single Zener diagram according to an embodiment.

The second smoothing unit 46 may be implemented as a smoothing capacitor connected in parallel to the output of the second rectifying unit 45 in order to rectify or detect the pulsating DC current output from the second rectifying unit 45 and output it as a DC current. .

The second inverter unit 47 converts the DC current passed through the second smoothing unit 46 into a variable high-frequency alternating current, and converts the DC current smoothed in the second smoothing unit 46 through one alternating switching. It can be implemented in the form of two insulated gate type bipolar transistors (IGBT) that convert to AC current.

The microprocessor 48 controls the entire operation of the three-phase inverter type current supply unit 40 and monitors the supply of abnormal current through a hall sensor, etc., and controls cleaning, crater current control, electric shock prevention operation, and heat dissipation. It plays a role of controlling the driving of the fan.

The mode selection switch 49 is connected to the microprocessor 48 described above. The mode selection switch 49 provides a switching signal to the microprocessor 48 while being operated according to the user's selection to control the operation of the second inverter unit 47 and its operation, implemented as a two-stage switch. It is possible.

When switching to the AC welding mode by the mode selection switch 49, the microprocessor 48 operates the second inverter unit 47 according to the input of the corresponding switching signal, so that the high frequency AC current is converted to the welding torch 20 ) To be applied to the electrode and the welding electrode 30.

In addition, in the case of switching to the DC welding mode by the mode selection switch 49, the microprocessor 48 deactivates the second inverter unit 47 according to the input of the corresponding switching signal to pass the direct current through the second smoothing unit 46. The current is applied to the electrode of the welding torch 20 and the welding electrode 30 as a welding current.

In the case of the inverter type argon gas welding machine according to an embodiment of the present invention as described above, whether the second inverter unit 47 for converting a variable high-frequency AC current to a DC current passed through the second smoothing unit 46 is operated As is formed in a structure controlled by the microprocessor 48 according to the switching operation of the mode selection switch 49, when the mode selection switch 49 switches to the AC welding mode, the second inverter unit 47 Is operated and the high-frequency AC current converted by the second inverter unit 47 is applied as a welding current to the electrodes of the welding torch 20 and the welding electrode 30, allowing AC argon gas welding, and the mode selection switch 49 ), when the second inverter unit 47 is switched to the AC welding mode, the DC current passing through the second smoothing unit 46 is used as the welding current as the electrode of the welding torch 20 and the welding electrode 30. ), cross-flow argon gas welding is possible.

In addition, when the mode selection switch 49 is switched to the AC welding mode, AC argon gas welding by high frequency AC current is possible, so that the peak arrival time is short and the power required is low.

Although some embodiments have been exemplarily described above, the fact that the present invention can be embodied in various forms without departing from the spirit and scope thereof is obvious to those of ordinary skill in the art. Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive, and all implementations within the scope of the appended claims and equivalents thereof will be included within the scope of the present invention.

10: main body
20: welding torch
30: welding electrode
40: 3-phase inverter type current supply unit
41: 1st rectification part
42: first smoothing section
43: first inverter unit
44: trans part
45: second rectification unit
46: second smoothing unit
47: second inverter unit
48: microprocessor
49: mode selection switch

Claims (3)

Main body 10;
A welding torch 20 connected to the body 10 and having an electrode therein;
A welding electrode 30 connected to the main body 10 and connected to a material to be welded;
It is installed in the body 40 and includes a three-phase inverter type current supply unit 40 for applying a current for welding to the electrode of the welding torch 20 and the welding electrode 30,
The three-phase inverter-type current supply unit 40 includes a first rectifier 41 that rectifies the AC current input into the three phases into a DC current, and a first rectifier that smoothes the DC current output from the first rectifier 41. 1 smoothing unit 42, a first inverter unit 43 that converts the DC current smoothed by the first smoothing unit 42 into a variable high-frequency AC current, and an AC output from the first inverter unit 43 A transformer unit 44 converting a current into a low voltage high current suitable for welding, a second rectifying unit 45 for converting the AC current output through the transformer unit 44 to a DC voltage again, and the second rectifying unit A second smoothing unit 46 smoothing the DC current output from 45, and the welding torch 20 according to whether or not operating the DC current passed through the second smoothing unit 46 is converted into a variable high-frequency AC current. A second inverter unit 47 providing a high-frequency alternating current or direct current to the electrodes of and the welding electrode 30, and a microprocessor 48 that controls the entire operation of the three-phase inverter type current supply unit 40 And, a three-phase inverter type argon including a mode selection switch 49 for controlling the operation of the second inverter unit 47 by providing a switching signal to the microprocessor 48 while a switching operation is performed according to the user's selection. Gas welding machine.
The method according to claim 1,
The first rectifier 41 is formed of a Zener diode, and the second rectifier 45 is formed of a full-wave rectifying bridge circuit including four diodes.
The method according to claim 1,
In the first inverter unit 43, four insulated gate type bipolar transistors (IGBT) are arranged in a full-bridge form, and the DC current smoothed by the first smoothing unit 42 is converted to a variable high-frequency alternating current through two alternating switching. And convert it to
In the second inverter unit 47, two insulated gate type bipolar transistors (IGBT) are arranged in parallel to convert the DC current smoothed by the second smoothing unit 46 into a variable high frequency AC current through one alternating switching. An inverter type argon gas welding machine, characterized in that.

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