KR100531427B1 - Microwave plasma torch and microwave plasma apparatus for local heating, cutting and welding - Google Patents

Abstract

The present invention relates to an electromagnetic plasma torch and an electromagnetic plasma welding system, and more particularly, to an electromagnetic plasma torch which generates microwaves easily and economically by generating microwaves using an electromagnetic wave oscillator and local heating of a metal by using the same. A welding system for cutting and joining.

A magnetron that emits electromagnetic waves and a power supply system installed to supply power to the magnetron, a waveguide that transmits electromagnetic waves generated from the magnetron, and supplies energy required for discharge, and induces a strong electric field by focusing the transmitted electromagnetic waves. And a discharge portion for generating a plasma, wherein the discharge portion is positioned at a distance of one quarter of the wavelength in the tube from the end of the waveguide, and has a cylindrical holder having a gas inlet at an upper end of the waveguide and a lower portion of the waveguide at the bottom of the holder. The nozzle coupled to the lower end is coupled, and the lower end of the waveguide in which the end of the nozzle is provided provides an electromagnetic plasma torch, characterized in that the electromagnetic plasma torch, local heating, cutting and Electron used for bonding A wave plasma welding system is provided.

Description

 Microwave plasma torch and microwave plasma apparatus for local heating, cutting and welding

The present invention relates to an electromagnetic plasma torch and an electromagnetic plasma welding system, and more particularly, to an electromagnetic plasma torch which generates microwaves easily and economically by generating microwaves using an electromagnetic wave oscillator and local heating of a metal by using the same. A welding system for cutting and joining.

In general, a plasma cutting machine generates an electric arc between an electrode and a base metal, and when air is injected through the nozzle through the nozzle, the air is ionized while passing through the arc airflow, thereby cutting the base metal while forming a high-speed, high-temperature jet plasma.

There are a variety of plasma torches, such as direct current arc torches, inductively coupled plasma torches and capacitively coupled high frequency torches, which provide conventional high temperature heat sources. DC arc torch directly applies electric field between two electrodes, so it is troublesome to replace electrode and uses high current of more than hundreds of amperes. Therefore, expensive current supply device requires high power consumption and operation cost. In addition, there is a problem that the energy efficiency of the inductively coupled plasma torch and the capacitively coupled high frequency plasma torch is very low to less than 40%.

As a result, such a conventional plasma torch has a high generation cost of plasma and many additional facilities.

Korean Patent No. 0375423, registered on February 26, 2003, was devised by HONG of the present inventors and relates to an apparatus for removing smoke emitted from a diesel engine using an electromagnetic plasma torch of 5000 to 6000 degrees Celsius. . According to this invention, an electromagnetic plasma torch is used to oxidize and remove soot by contacting the electromagnetic plasma with soot discharged from a diesel engine. The electromagnetic plasma torch uses an inner diameter of 22 to 30 mm in the discharge tube, and as in the present invention, it is difficult to centralize the plasma in a high temperature region to a few hundred μm in diameter and to concentrate it on the base material to be cut and locally heated.

The present invention has been made to solve the conventional problems as described above by using a conventional electromagnetic wave oscillator to focus the microwave at a specific position to induce a very strong electric field and thereby generate a high temperature electromagnetic plasma electromagnetic wave torch And to provide a welding system using the electromagnetic plasma torch to local heating, cutting and bonding the base material using the same.

In order to achieve the above object, the present invention adds a high-voltage capacitor and a high-voltage diode to a magnetron 22 that oscillates a typical 2.45 GHz electromagnetic wave and a conventional three-phase rectifier or a conventional half-wave voltage multiplier to supply power to the magnetron 22. It includes a power supply system 24 is installed to supply the waveguide 18 for transmitting the energy required to discharge by transmitting the electromagnetic wave generated from the magnetron 22. In addition, when the wavelength of the electromagnetic wave transmitted in the waveguide 18 is λ _g , the discharge portion is disposed at a distance of a quarter of the tube wavelength from the waveguide terminal 20 having the strongest electric field in the waveguide 18. Located. The discharge part is coupled to the upper end portion 19 of the waveguide and the cylindrical holder 40 having a gas inlet 16 at the center thereof, and the nozzle 12 coupled to the lower end 29 of the waveguide at the lower portion of the holder 40. ). The lower end 29 of the waveguide in which the nozzle tip 8, which is the distal end of the nozzle 12, is located comprises a circular hole 10. The discharge unit focuses electromagnetic waves at a specific position to induce a very strong electric field, thereby generating an electromagnetic plasma having a high temperature. The ring 14 coupled to the inner periphery of the hole 10 is separately attached to prevent damage to the waveguide 18 generated by the arc when impedance matching is not made. The ring 14 Is composed of a conductor with good wear resistance and heat resistance. In this case, impedance matching or impedance matching generally refers to all methods for reducing reflection due to impedance difference between two different connection terminals when connecting one output terminal and an input terminal. Impedance matching in the present invention is to minimize the reflected wave generated by the difference between the impedance of the electromagnetic wave oscillated in the magnetron and the load impedance of the plasma generated from the nozzle. In the present invention, adjustment is possible by varying the insertion depth of the holder with which the nozzle is coupled into the waveguide. The gas to be reacted with the plasma gas passes through the gas inlet 16 inside the nozzle 12, and the nozzle tip 8 is caused by a strong electric field between the hole 10 and the nozzle tip 8. The plasma gas and the reactive gas are discharged to generate the jet-type high temperature plasma 6. The nozzle 12 is detachable from the holder 40 to allow adjustment of the insertion depth, and the plasma nozzle tip 8 may be configured in a tapered form. The base material 50 to be locally heated, cut and bonded is processed by the electromagnetic plasma torch 100 while being moved up, down, left and right at a constant speed by a conventional conveyor system 54. In addition, the electromagnetic plasma torch 100 may provide a welding system in which a plurality of localized materials 50 are locally heated, cut, and joined at the same time.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to one embodiment of the invention, the waveguide 18 is divided into a microwave head waveguide 18b and a reactor waveguide 18a, as shown in FIG. It is connected. The magnetron 22, which supplies microwaves to the waveguide 18b, is a 2.45 GHz electromagnetic wave oscillator commonly used in a microwave oven and is powered by a power supply system 24 composed of a three-phase rectifier or a full-wave voltage multiplier. Overheating is prevented by the device 26 and the chiller is constructed by conventional techniques such as cooling fans.

In addition, when the wavelength of the electromagnetic wave transmitted in the waveguide 18 is λ _g , the discharge portion is disposed at a distance of a quarter of the tube wavelength from the waveguide terminal 20 having the strongest electric field in the waveguide 18. Located. The discharge part is coupled to the upper end portion 19 of the waveguide and the cylindrical holder 40 having a gas inlet 16 at the center thereof, and the nozzle 12 coupled to the lower end 29 of the waveguide at the lower portion of the holder 40. ). The lower end 29 of the waveguide in which the nozzle tip 8, which is the distal end of the nozzle 12, is located comprises a circular hole 10. The discharge unit focuses electromagnetic waves at a specific position to induce a very strong electric field, thereby generating an electromagnetic plasma having a high temperature. The nozzle 12 is connected to a holder 40 having a gas inlet 16, and the holder 40 and the nozzle 12 are connected like a female screw and a male screw to be separated from each other. The nozzle 12 is installed through the lower end 29 from the upper end 19 of the waveguide 18a and the nozzle 12 so that the nozzle tip 8 can be led to the lower end 29 of the waveguide 18a. A central hole 10 such as) is provided in the lower end 29 of the waveguide 18a. The ring 14 provided in the hole 10 of the lower end 29 of the waveguide 18a is a waveguide (generated by an arc between the nozzle tip 8 and the ring 14) when impedance matching is not achieved. Attached separately to prevent damage to 18a), the ring 14 is comprised of a good wear and heat resistant conductor. The holder 40 is connected to a cooling jacket 42 attached to the upper end 19 of the waveguide 18a. The cooling jacket 42 includes a cooling water inlet 30 and an outlet 32. 40) and detachable. The nozzle 12 made of tungsten, stainless steel, brass, or the like is adapted to adjust the height from the lower end 29 of the conduit 18a by the holder 40 and at the same time the waveguide of the holder 40 18a) The impedance penetration can be induced by adjusting the depth of space penetration between the upper end 19 and the lower end 29. Depending on the application, the inner diameter of the plasma nozzle 12 can vary from several hundred μm to several tens of mm.

The microwaves oscillated from the magnetron 22 are transmitted through the waveguide 18 and the plasma gas injected from the plasma gas inlet 16 is ionized by a strong electric field between the nozzle tip 8 and the ring 14 so that the high temperature, A high velocity jet plasma 6 is produced.

The substrate 50 mounted on the spacer 52 by a conventional conveyor system 54 that can move the distance from the jet-type plasma 6 torch to an adjustable position up, down, left and right is heated locally by a jet-type plasma 6 torch. , Cut and joined.

FIG. 2 is a cross-sectional view of the portion indicated by reference numeral 80 of FIG. 1, wherein the 2.45 kHz microwave 60 transmitted through waveguide 18 is connected to the lower end of waveguide 18a by electromagnetic inductive coupling with nozzle 12. The plasma gas ejected through the plasma nozzle hole 4 is ionized by a strong electric field between the ring 14 and the nozzle tip 8 of 29 to generate a jet plasma.

3 is a longitudinal cross-sectional view of an apparatus for locally heating, cutting, and joining a large number of base materials by connecting a plurality of electromagnetic plasma torches 100 simultaneously. The discharge parts of the plurality of electromagnetic plasma torch 100 are connected and assembled by the package box 90, and jet-type plasma is ejected into the package box hole 92. The plasma gas supply device 36 supplies plasma gas to each of the plurality of discharge units. The waveguide, the magnetron, and the power supply are connected to each of the plurality of discharge parts, and a plurality of the discharge parts are configured in one set to simultaneously localize and cut a large number of the base materials 50 at regular intervals, and a large amount of the base material. (50) can be bonded.

4 is a bottom view illustrating an example of an arrangement of a plurality of electromagnetic wave plasma torch 100 discharge parts of FIG. 3. Through holes 92 of the package box 90, portions indicated by reference numeral 110 are shown in FIGS. 3 and 4. In addition, by discharging the discharge portions of the electromagnetic wave plasma torch 100 in a circular manner, one base material 50 may be heated at a uniform and fast time.

5 is a plasma flame photograph generated using the electromagnetic plasma torch 100. At this time, argon gas was injected, the applied microwave power was 300 watts, and the inner diameter of the nozzle was 1.5 mm.

Experimental Example

It was confirmed that plasma can be easily generated by using gases such as nitrogen, air, and argon using a magnetron capacity of 900 W. The size of the nozzle was changed by changing the size of inner diameter and outer diameter from outer diameter 1 mm, inner diameter 0.5 mm to outer diameter 10 mm, inner diameter 6 mm, and plasma was easily generated at all nozzle sizes. The long plasma flame of about 20 cm was observed in 1 mm of inner diameter, 900 W of microwave power, and 1 liter of argon gas.

In a 300 W-powered argon plasma, a quartz tube with an outer diameter of 8 mm and an inner diameter of 5.5 mm was melted while rotating, and a 150 μm-thick quartz fiber was extracted, and a 2 mm thick carbon steel was cut from an 600 W argon plasma with an electromagnetic plasma torch. And made holes of various sizes.

The present invention can generate a plasma easily and economically through a nozzle installed at a specific position of the plate by oscillating the microwave using a conventional 2.45 GHz electromagnetic wave oscillator, the structure is simple, the price is low, and the high temperature It is possible to generate a high-speed plasma jet, and to obtain an effect that can be used for cutting, bonding, and local heating of the base material. In addition, a plurality of electromagnetic plasma torch can be rearranged and newly changed, and at the same time, the effect of cutting, bonding, and local heating of many base materials can be obtained.

1 is a longitudinal cross-sectional view illustrating the present invention;

FIG. 2 is a cross sectional view of a portion indicated by reference numeral 80 in FIG. 1, FIG.

Figure 3 is a longitudinal sectional view showing another example of the present invention,

4 is a bottom view showing an example of the plurality of electromagnetic plasma torch arrangement of FIG.

Figure 5 is a plasma flame picture of the present invention. ** Description of the symbols for the main parts of the drawings ** 6: Jet-type high temperature plasma 8: Nozzle tip 10: Hole 12: Nozzle 14: Ring 16: Gas injection portion 18: Waveguide 19: Waveguide upper part 20: Waveguide end 29: Waveguide lower end 22: Magnetron 24: Power supply system 26: Cooling device 28: Flange 30: Cooling water inlet 32: Cooling water outlet 40: Holder 42: Cooling jacket 50: Base material 52: Spacer 54: Kenvey System 100: Torch

Claims (11)

A magnetron that oscillates electromagnetic waves; A power supply system installed to supply power to the magnetron; A waveguide which transmits electromagnetic waves oscillated from the magnetron to supply energy for discharge; And a discharge unit focusing the transmitted electromagnetic waves to induce a strong electric field and generate a high temperature plasma. The discharge portion is located at a distance of a quarter of the tube wavelength from the end of the waveguide, the upper end of the waveguide and the cylindrical holder having a gas inlet and a nozzle coupled to the lower end of the waveguide at the bottom of the holder is coupled And a circular hole at a lower end portion of the waveguide at which the end of the nozzle is located. The method of claim 1, wherein the holder, The electromagnetic wave plasma torch, which is detachably attached to the upper end of the waveguide and is capable of adjusting a depth inserted into the waveguide. The method of claim 1 or 2, wherein the nozzle, Electromagnetic plasma torch, which is detachable from the holder and is adjustable in depth to be inserted into the holder. The method of claim 1, An electromagnetic plasma torch characterized by generating an atmospheric plasma using a plasma gas and a reaction gas using a magnetron operating at an operating frequency of 2.45 kHz and a power range of 0.6 to 1.4 kW. The method of claim 3, wherein Electromagnetic plasma torch, characterized in that the size of the central hole of the nozzle tip through which the gas is injected is 0.5mm ~ 6mm. The method of claim 3, wherein the nozzle, Electromagnetic plasma torch, characterized in that the distal end of the nozzle is tapered to generate a strong electric field. The method of claim 3, wherein the nozzle, Electromagnetic plasma torch, characterized in that the installation direction is installed so as to be perpendicular to the transmission direction of the electromagnetic wave. The method of claim 1, Electromagnetic plasma torch, characterized in that the ring of the conductor is added to the inner circumference of the hole to prevent damage to the waveguide caused by the arc. And a base material providing means positioned below the electromagnetic plasma torch of claim 1 and movable up, down, left, and right. And said electromagnetic plasma torch is used for local heating, cutting or joining of a base material. The method of claim 9, wherein the base material providing means, Electromagnetic plasma welding system, characterized in that the conveyor system. The method of claim 9, An electromagnetic plasma welding system comprising local heating, cutting or joining a plurality of base materials simultaneously by including a plurality of electromagnetic plasma torches.