CN106735799B

CN106735799B - Plasma arc cutting torch

Info

Publication number: CN106735799B
Application number: CN201710040511.XA
Authority: CN
Inventors: 潘宇锋
Original assignee: Changzhou Jiusheng Welding And Cutting Equipment Co ltd
Current assignee: Changzhou Jiusheng Welding And Cutting Equipment Co ltd
Priority date: 2017-01-20
Filing date: 2017-01-20
Publication date: 2022-08-26
Anticipated expiration: 2037-01-20
Also published as: CN106735799A

Abstract

The invention provides a plasma arc cutting torch, which comprises a cutting torch body, an electrode and a nozzle, wherein an inner hole of the nozzle is designed into a circular horn shape, a center hole is arranged in the center of the nozzle, the shape of the nozzle is a sectional type horn mouth, and the main material is processed by red copper. The electrode is arranged in the nozzle and is arranged on the electrode base, the middle end of the shape is recessed inwards, the whole nozzle is designed into a gourd shape, the space between the nozzle and the electrode is enlarged, and positive ions on the electrode are prevented from being emitted onto the nozzle at a non-central hole, so that the double-arc effect is avoided.

Description

Plasma arc cutting torch

Technical Field

The invention relates to the technical field of arc cutting torches, in particular to a plasma arc cutting torch.

Background

The existing machine-used plasma arc cutting torch in the Chinese market has the advantages of simple design structure, poor production and manufacturing process, no technical college in the aspect at home, lack of technical knowledge education, most of the machine-used plasma arc cutting torch is simulated foreign technology even if being produced by manufacturers, and no independent innovation in cutting torch design capability exists, so that the technology is always behind the era, and the manufactured cutting torch has a series of problems of weak cutting capability, poor cutting quality, short service life of consumed parts, high use cost and the like. When the current reaches 120A or above in the domestic market, the inside of the cutting torch body must adopt a water circulation cooling mode, and the maximum current of the internal gas cooling mode of the cutting torch in developed countries in the United states only reaches 125A.

As shown in fig. 1, in the plasma arc torch according to the related art, a phenomenon that stable combustion of an arc is broken sometimes occurs due to a structural defect, and in addition to an existing main arc 05 of the plasma arc, another bypass arc 04 (or, called, an auxiliary arc) is generated between an electrode 01, a nozzle 02 and a workpiece 03, that is, the main arc 05 and the bypass arc 04 exist at the same time, and a double arc phenomenon is formed.

The harm caused by the double arc phenomenon is mainly shown in the following aspects:

1) the stability of the plasma arc is damaged, so that the cutting process is unstable and the cutting seam forming is deteriorated;

2) the double arcs exist simultaneously, two parallel conductive paths are formed between the electrode and the cutting piece, the main arc current is reduced, the power of the main arc is reduced, and the penetration capability of the cutting piece is weakened;

3) once the double arc phenomenon occurs, the nozzle becomes an electrode of the parallel arc and passes through the parallel arc current, and a cold air film barrier between the main arc and the inner wall of the nozzle hole is damaged, so that the nozzle is heated strongly and is easy to burn out.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to overcome the defects in the prior art, the invention provides a plasma arc cutting torch.

The technical scheme adopted for solving the technical problems is as follows: a plasma arc cutting torch comprises a cutting torch body, wherein an upper inner insulator is arranged at the rear part in the cutting torch body, a gas pipe and an arc striking wire are arranged in the upper inner insulator, a nozzle is arranged at the front part of the cutting torch body and is connected with the outer edge of the upper inner insulator through a nozzle base, the rear part of the nozzle base is connected with the arc striking wire, an inner hole of the nozzle comprises a spherical part and a conical part which are sequentially connected from bottom to top, the spherical part and the conical part form a circular horn shape integrally, a central hole is formed in the center of the spherical part, an electrode base is connected onto the upper inner insulator in the nozzle base, the front part of the electrode base is connected with an electrode, the electrode extends forwards into the spherical part of the nozzle inner hole, the middle part of the outer wall of the electrode is recessed inwards to form a gourd shape integrally, and a plasma gas channel is formed between the outer wall of the electrode and the nozzle inner hole, be equipped with central trachea in the electrode base, central trachea intercommunication the trachea with the hole of electrode, still be equipped with down the internal insulator between electrode base and the spout base, the internal insulator is used for distributing the air current and realizes insulating between spout and the electrode down, spout outside cover is equipped with the safety cover, the anterior spout base outside of cutting torch body is equipped with the copper overcoat, the safety cover rear portion with copper overcoat fixed connection, just copper overcoat and safety cover inner wall with form the cooling gas passageway between the spout outer wall, still be equipped with the air current distribution structure on central trachea, electrode base, the internal insulator and the spout base down, plasma gas passageway and cooling gas passageway pass through the air current distribution structure with central trachea intercommunication.

Due to the adsorption effect of the ions, the ions are integrated on the surface area of the conductor to move, so that the positive and negative ions between the electrode and the nozzle are easy to combine to form an electric arc, and the double-arc effect is generated. And the internal pressure is seriously weakened due to the internal strong pressure gas mobility, so that the opportunity is created for the mobility of the electric ions. Therefore, the inner hole of the nozzle is designed to be a circular horn shape, the center of the nozzle is provided with a central hole, the appearance of the nozzle is a sectional type horn mouth, and the main material is processed by red copper. The electrode is arranged in the nozzle, the electrode is arranged on the electrode base, the middle end of the shape is recessed inwards, the whole nozzle is designed into a gourd shape, and the space between the nozzle and the electrode is enlarged, so that the cold air film barrier between the arc column and the wall of the nozzle hole is increased, positive ions on the electrode are prevented from being emitted to the nozzle at a non-central hole, the double-arc effect is avoided, and the stability of plasma is ensured. A hafnium wire is embedded in the center of the lower end plane, and the main material is processed by red copper.

In addition, the circular concave shape of the outer wall of the electrode can guide more gas to walk on the surface of the electrode, so that positive ions of a nozzle at the lower end of the electrode are easier to emit to the electrode with a negative electrode, and the success of ignition is enhanced.

Preferably, the recessed portion of the outer wall of the electrode is opposite to the conical portion of the spout. The conical part at the tail end of the nozzle is aligned with the concave position of the outer wall of the electrode, the distance between the conical part and the electrode is increased, and the increase of the thickness of the cold air film barrier is facilitated.

Further, electrode front end plane central point puts and inlays a hafnium silk, the electrode hole is the blind hole, the bottom of blind hole is equipped with the toper bump, the top of toper bump stretches into in the central trachea, the blind hole inner wall is the step hole, and is close to the internal diameter of blind hole bottom and is less than the open end internal diameter, central trachea is equipped with the boss on being close to the hole lateral wall of the one end of toper bump, the aperture of boss is less than the aperture of central trachea rear end, distance between central trachea outer wall and the electrode inner wall is less than central tracheal hole aperture.

The conical salient points can increase the internal heat dissipation area; more gas ions passing through the conical surface can contact the conical surface, so that the heat dissipation performance is enhanced; the air current that can let pass through forms the diffusivity direction, makes the air current of central trachea export can be better paste the walking of electrode inner wall, reinforcing thermal diffusivity.

The electrode is internally designed into a stepped hole, the front end of the central air pipe is also provided with a small caliber, and when gas enters between the electrode and the central air pipe from the central air pipe, the caliber is reduced to enable the compressed gas to be compressed for the second time, so that the compression density is enhanced, the volume of the high-density gas can generate a heat absorption principle when the outlet can expand instantly, and the high temperature at the bottom of the electrode valley is reduced better.

Further, the gas flow distribution structure comprises an annular first flange arranged on the outer wall of the central gas pipe, a first gas hole and a second gas hole which are arranged on the electrode base, a third gas hole which is arranged on the lower inner insulator and a fourth gas hole which is arranged on the front end face of the nozzle base, wherein the side face of the first flange is abutted against the inner wall of the electrode base, the upper end face of the first flange, the outer wall of the central gas pipe and the inner wall of the electrode base define a first cooling gas chamber, the lower end face of the first flange, the outer wall of the central gas pipe and the inner wall of the electrode base define a first plasma gas chamber, and a plurality of gas guide grooves which are communicated with the first cooling gas chamber and the first plasma gas chamber are axially arranged on the first flange;

the electrode base is provided with a first annular groove and a second annular groove on the outer wall, a second flange is formed between the first groove and the second groove, the side face of the second flange is abutted against the inner wall of the lower inner insulator, the first groove and the inner wall of the lower inner insulator form a second cooling gas chamber, a third cooling gas chamber is formed between the inner wall of the nozzle base and the outer wall of the lower inner insulator, two ends of the first gas hole are communicated with the first cooling gas chamber and the second cooling gas chamber, two ends of the third gas hole are communicated with the second cooling gas chamber and the third cooling gas chamber, and the fourth gas hole is communicated with the third cooling gas chamber and the cooling gas channel; the second groove and the inner wall of the lower inner insulator form a second plasma gas chamber, the second gas hole is communicated with the first plasma gas chamber and the second plasma gas chamber, a plurality of rotary gas grooves are formed in the front end face of the electrode base, and the rotary gas grooves are communicated with the second plasma gas chamber and a plasma gas channel.

The plasma arc gas and the cooling gas are simultaneously generated by adopting one gas source through the gas flow distribution structure, so that the cutting and the cooling can be simultaneously realized.

Further, the aperture of the first gas hole is larger than that of the second gas hole, the volume of the first cooling gas chamber is smaller than that of the first plasma gas chamber, the volume of the first cooling gas chamber is smaller than that of the second cooling gas chamber, the volume of the second cooling gas chamber is smaller than that of the third cooling gas chamber, and the volume of the first plasma gas chamber is larger than that of the second plasma gas chamber. The control of the cooling airflow and the plasma airflow is realized by controlling the aperture of the air hole and the volume of the gas chamber, so that the stability of the plasma arc is realized. In addition, the cooling gas can be further compressed by controlling the pore diameter of the air hole and the volume of the gas chamber, so that the gas at the nozzle is rapidly expanded to realize rapid cooling.

Further, the copper overcoat includes copper overcoat insulating part and copper overcoat copper spare, copper overcoat insulating part and the outer wall fixed connection who stretches out the spout base of cutting torch body, copper overcoat copper spare one end with copper overcoat insulating part outer wall fixed connection, the other end through fixed lid with safety cover fixed connection.

Furthermore, a first sealing ring is arranged on the connecting surface of the lower inner insulator and the electrode base, and a second sealing ring is arranged on the connecting surface of the lower inner insulator and the nozzle base.

The plasma arc cutting torch provided by the invention has the following beneficial effects:

(1) the protective cover is a specially added accessory when the plasma machine automatically works, the quality of cutting is directly determined by the nozzle, the protective cover can effectively protect the nozzle and reduce damage, and therefore the protective cover plays a role in protection. In addition, the protective gas outside the nozzle can be compressed, and the cutting capability is enhanced. The thermal diffusivity can be strengthened to a week aperture at safety cover front end, prolongs the life of safety cover.

(2) The function of the nozzle is as follows: the ion arc generated by the electrode is focused and sprayed out through the small hole in the center of the nozzle to generate a high-energy cutting ion arc, and the circular horn shape in the nozzle mainly avoids the generation of a double-arc effect with the vortex gas between the nozzle and the electrode. The sectional type horn mouth design of spout appearance enables the more even production compression of the protection air current in the spout outside to compress the ion arc that the spout came out, further improved the rigidity of ion arc, strengthened the cutting ability of during operation.

(3) The electrode is the largest consumable part in the whole set of cutting torch, and is processed by red copper, and the red copper material has good electric conduction and heat conduction effects. The inner step holes and the conical salient points can mainly enhance the airflow speed and the heat dissipation area at the bottommost part, thereby improving the heat dissipation effect of the electrode, directly prolonging the service life of the electrode and reaching more than 3 times of the service life of domestic similar products. The design of the shape of the middle-end gourd-shaped part mainly avoids the double-arc effect generated by the eddy gas between the middle-end gourd-shaped part and the nozzle.

(4) The central air pipe is made of brass, and the material of the central air pipe is hard and high-temperature resistant, so that cooling gas can be directly introduced into the electrode, and severe high temperature generated by the electrode during working can be rapidly discharged, and the service life of the electrode is prolonged. The air guide groove in the middle can uniformly distribute airflow guide and improve heat dissipation capacity.

(5) The fixed cover is screwed on the copper outer sleeve, and the surface of the fixed cover is knurled mainly for fixing the protective cover on the copper outer sleeve, so that the heat dissipation of the surface area is greatly enhanced, and the service life is prolonged.

(6) The copper jacket is a connecting piece of the protective cover and the cutting torch body, small air holes distributed on the circumference of the groove in the middle of the copper piece can effectively reduce the temperature and prolong the service life, and can form a protective air layer to damage the cutting torch body when the cutting torch is prevented from splashing and rising. The upper insulator is made of high-temperature-resistant polymer materials, and is mainly used for isolating the copper body of the outer part, so that the direct short circuit phenomenon between the nozzle and a cut workpiece is avoided, and the safety protection performance can be enhanced.

(7) The inside vortex design that adopts of cutting torch body can let the inside air current of electrode base trachea inflow cutting torch produce the vortex rotatory, makes finally produced vortex plasma arc more even, more straight, stronger penetrability.

Drawings

The invention is further illustrated by the following figures and examples.

FIG. 1 is a schematic diagram of the double arc effect;

FIG. 2 is a schematic structural diagram of a preferred embodiment of the present invention;

FIG. 3 is an enlarged partial schematic view of FIG. 2;

FIG. 4 is an enlarged schematic view of A in FIG. 3;

fig. 5 is a schematic gas flow diagram.

In the figure: 01. an electrode, 02, a nozzle, 03, a workpiece, 04, a main arc, 05, a bypass arc, 1, a protective shield, 2, a nozzle, 3, an electrode, 4, a central gas pipe, 5, a fixed cover, 6, a copper-clad copper piece, 7, a copper-clad insulator, 8, an electrode base, 9, a lower inner insulator, 10, a nozzle base, 11, an arc striking wire, 12, a gas pipe, 13, a torch body, 14, an upper inner insulator, 15, a second cooling gas chamber, 16, a third cooling gas chamber, 17, a third gas hole, 18, a first gas hole, 19, a first cooling gas chamber, 20, a first flange, 21, a second gas hole, 22, a second plasma gas chamber, 23, a second seal ring, 24, a first small gas hole, 25, a fourth gas hole, 26, a plasma gas channel, 27, a central hole cooling gas channel, 28, a second small gas hole, 29, 26, 30, a first plasma gas chamber, 31. the first sealing ring 33, the boss 34, the conical salient point 35 and the stepped hole.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, and only illustrates the basic structure of the present invention in a schematic manner, and therefore it only shows the constitution related to the present invention.

2-5, the plasma arc cutting torch of the invention comprises a cutting torch body 13, an upper inner insulator 14 is arranged at the rear part in the cutting torch body 13, a gas pipe 12 and an arc striking wire 11 are arranged in the upper inner insulator 14, and the upper inner insulator 14 adopts ceramic materials and mainly isolates the high-frequency voltage of a spout base 10 and an electrode base 8 of an outer layer. The front portion of cutting torch body 13 is equipped with spout 2, spout 2 through spout base 10 with go up the outer fringe of internal insulator 14 and connect, just spout base 10 rear portion with it connects to draw pitch arc 11, the hole of spout 2 includes that spherical portion and the toper portion that from the bottom up connected gradually form circular loudspeaker form, the center of spherical portion is equipped with centre bore 29, be connected with electrode base 8 on the internal last internal insulator 14 of spout base 10, electrode base 8 front portion connects electrode 3, electrode 3 forward extends to in the spherical portion of 2 holes of spout, the inward concave yield of electrode 3 outer wall middle part forms the calabash shape, the part of electrode 3 outer wall concave yield with the toper portion of spout 2 is relative. The electrode 3 is a negative electrode and can generate plasma arc, and the nozzle 2 is a positive electrode and can focus the plasma arc to be sprayed out at high density.

A plasma gas channel 26 is formed between the outer wall of the electrode 3 and the inner hole of the nozzle 2, a central gas pipe 4 is arranged in the electrode base 8, the central air pipe 4 is communicated with the air pipe 12 and the inner hole of the electrode 3, a lower inner insulator 9 is also arranged between the electrode base 8 and the spout base 10, the lower inner insulator 9 is used for distributing air flow and realizing insulation between the spout 2 and the electrode 3, the outer side of the spout 2 is covered with a protective cover 1, the outer side of the nozzle base 10 at the front part of the cutting torch body 13 is provided with a copper jacket, the rear part of the protective cover 1 is fixedly connected with the copper jacket, and a cooling gas channel 27 is formed between the copper jacket and the inner wall of the protective cover 1 and the outer wall of the spout 2, the central air pipe 4, the electrode base 8, the lower inner insulator 9 and the nozzle base 10 are also provided with an air flow distribution structure, the plasma gas channel 26 and the cooling gas channel 27 communicate with the central gas pipe 4 through a gas flow distribution structure.

The copper jacket is screwed on the cutting torch body 13 and consists of two parts, the copper jacket comprises an upper copper jacket insulating part 7 and a lower copper jacket copper part 6, a plurality of first small air holes 24 are distributed on the circumference of a middle groove at the joint of the copper jacket insulating part 7 and the copper jacket copper part 6, the upper copper jacket insulating part 7 is made of a high-polymer high-temperature-resistant material and mainly used for isolating a copper body of an outer part, the direct short circuit phenomenon of the nozzle 2 and a cut workpiece is avoided, and the safety protection performance can be enhanced. The cutting torch comprises a cutting torch body 13, a copper outer sleeve insulating part 7, a nozzle base 10, a copper outer sleeve copper part 6 and a protective cover 1, wherein the nozzle base 10 extends out of the cutting torch body 13, one end of the copper outer sleeve copper part is fixedly connected with the outer wall of the copper outer sleeve insulating part 7, and the other end of the copper outer sleeve copper part is fixedly connected with the protective cover 1 through a fixing cover 5. The assembly of safety cover 1 is on copper

overcoat copper spare

6, and 1 front end equipartition a week second small air hole 28 of safety cover, second small air hole 28 have give vent to anger and radiating effect, and the main part material uses red copper processing, and fixed lid 5 is twisted on copper overcoat copper spare 6, compresses tightly safety cover 1, uses the brass material, and the surface adopts the annular knurl processing.

3 front end plane central points of electrode puts and inlays a hafnium filament, 3 holes of electrode are the blind hole, the bottom of blind hole is equipped with toper bump 34, the top of toper bump 34 stretches into in central trachea 4, the blind hole inner wall is step hole 35, and the internal diameter that is close to the blind hole bottom is less than the open end internal diameter, central trachea 4 is equipped with boss 33 on being close to the hole lateral wall of the one end of toper bump 34, the aperture of boss 33 is less than the aperture of 4 rear ends of central trachea, distance between 4 outer walls of central trachea and the 3 inner walls of electrode is less than the hole aperture of central trachea 4.

The gas flow distribution structure comprises an annular first flange 20 arranged on the outer wall of the central gas pipe 4, a first gas hole 18 and a second gas hole 21 arranged on the electrode base 8, a third gas hole 17 arranged on the lower inner insulator 9 and a circle of fourth gas holes 25 arranged on the front end surface of the nozzle base 10, wherein the first gas hole 18, the second gas hole 21, the third gas hole 17 and the fourth gas holes 25 are all small holes, the side surface of the first flange 20 is abutted against the inner wall of the electrode base 8, the upper end surface of the first flange 20, the outer wall of the central gas pipe 4 and the inner wall of the electrode base 8 enclose a first cooling gas chamber 19, the lower end face of the first flange 20, the outer wall of the central gas pipe 4 and the inner wall of the electrode base 8 enclose a first plasma gas chamber 30, a plurality of gas guide grooves which are communicated with the first cooling gas chamber 19 and the first plasma gas chamber 30 are axially arranged on the first flange 20; a first annular groove and a second annular groove are formed in the outer wall of the electrode base 8, a second flange is formed between the first annular groove and the second annular groove, the side face of the second flange is abutted to the inner wall of the lower inner insulator 9, an inward concave groove is formed in the side face of the second flange, a first sealing ring 31 is arranged in the concave groove, a second cooling gas chamber 15 is formed between the first annular groove and the inner wall of the lower inner insulator 9, a third cooling gas chamber 16 is formed between the inner wall of the nozzle base 10 and the outer wall of the lower inner insulator 9, two ends of a first gas hole 18 are communicated with a first cooling gas chamber 19 and a second cooling gas chamber 15, two ends of a third gas hole 17 are communicated with the second cooling gas chamber 15 and the third cooling gas chamber 16, and a fourth gas hole 25 is communicated with the third cooling gas chamber 16 and a cooling gas channel 27; the second groove and the inner wall of the lower inner insulator 9 form a second plasma gas chamber 22, the second gas hole 21 is communicated with the first plasma gas chamber 30 and the second plasma gas chamber 22, the front end face of the electrode base 8 is provided with a plurality of rotary gas grooves, and the rotary gas grooves are communicated with the second plasma gas chamber 22 and the plasma gas channel 26. And a concave recess is arranged on the connecting surface of the lower inner insulator 9 and the nozzle base 10, and a second sealing ring 23 is arranged in the concave recess.

The first gas holes 18 have a larger hole diameter than the second gas holes 21, the first cooling gas chamber 19 has a smaller volume than the first plasma gas chamber 30, the first cooling gas chamber 19 has a smaller volume than the second cooling gas chamber 15, the second cooling gas chamber 15 has a smaller volume than the third cooling gas chamber 16, and the first plasma gas chamber 30 has a larger volume than the second plasma gas chamber 22.

The arrows in fig. 5 indicate the flow direction of the gas.

In addition, the secondary compression is realized on the compressed gas through the design of the inner hole structure of the electrode 3 and the matching of the pore diameter of the air hole and the volume of the gas chamber, so that the cooling effect is improved, and the service lives of the electrode 3 and the nozzle 2 are prolonged; through the improvement of the comprehensive structure, the actual use current of the HC-1303 cutting torch of the prior product can reach 130A, and the use convenience is greatly improved by adopting an internal air cooling mode. And the quality of the cutting product of the HC-1303 cutting torch reaches the cutting quality of the American original import cutting torch, and the service life of the consumable part is 1.2 times longer than that of the consumable part of the American original import cutting torch, so that the working efficiency and the consistency of high-quality cutting products are improved, and the price of domestic consumable parts is low, thereby greatly improving the use cost performance of a terminal user.

In light of the foregoing description of preferred embodiments in accordance with the invention, it is to be understood that numerous changes and modifications may be made by those skilled in the art without departing from the scope of the invention. The technical scope of the present invention is not limited to the contents of the specification, and must be determined according to the scope of the claims.

Claims

1. A plasma arc torch, comprising: the cutting torch comprises a cutting torch body (13), an upper inner insulator (14) is arranged at the rear part in the cutting torch body (13), a gas pipe (12) and an arc striking line (11) are arranged in the upper inner insulator (14), a nozzle (2) is arranged at the front part of the cutting torch body (13), the nozzle (2) is connected with the outer edge of the upper inner insulator (14) through a nozzle base (10), the rear part of the nozzle base (10) is connected with the arc striking line (11), an inner hole of the nozzle (2) comprises a spherical part and a conical part which are sequentially connected from bottom to top, a central hole (29) is formed in the center of the spherical part, an electrode base (8) is connected onto the upper inner insulator (14) in the nozzle base (10), an electrode (3) is connected with the front part of the electrode base (8), and the electrode (3) extends forwards to the spherical part of the inner hole of the nozzle (2), the electrode (3) outer wall middle part is inside recessed, electrode (3) outer wall with form plasma gas passageway (26) between spout (2) hole, be equipped with central trachea (4) in electrode base (8), central trachea (4) intercommunication trachea (12) with the hole of electrode (3), still be equipped with down internal insulation body (9) between electrode base (8) and spout base (10), internal insulation body (9) are used for distributing the air current and realize insulating between spout (2) and electrode (3) down, spout (2) outside cover is equipped with safety cover (1), spout base (10) the outside of cutting torch body (13) front portion is equipped with the copper overcoat, safety cover (1) rear portion with copper overcoat fixed connection, just copper overcoat and safety cover (1) inner wall with form cooling gas passageway (27) between spout (2) outer wall, the central gas pipe (4), the electrode base (8), the lower inner insulator (9) and the nozzle base (10) are also provided with gas flow distribution structures, and the plasma gas channel (26) and the cooling gas channel (27) are communicated with the central gas pipe (4) through the gas flow distribution structures;

the concave part of the outer wall of the electrode (3) is opposite to the conical part of the nozzle (2); thereby enlarging the space between the nozzle and the electrode to avoid double arc effect;

a hafnium wire is inlaid in the center position of the front end plane of the electrode (3), the inner hole of the electrode (3) is a blind hole, a conical salient point (34) is arranged at the bottom of the blind hole, the top of the conical salient point (34) extends into the central air pipe (4), the inner wall of the blind hole is a stepped hole (35), the inner diameter close to the bottom of the blind hole is smaller than the inner diameter of an opening end, a boss (33) is arranged on the inner hole side wall of one end, close to the conical salient point (34), of the central air pipe (4), the aperture of the boss (33) is smaller than that of the rear end of the central air pipe (4), and the distance between the outer wall of the central air pipe (4) and the inner wall of the electrode (3) is smaller than that of the inner hole of the central air pipe (4);

the air flow distribution structure comprises an annular first flange (20) arranged on the outer wall of the central air pipe (4), a first air hole (18) and a second air hole (21) arranged on the electrode base (8), a third air hole (17) arranged on the lower inner insulator (9) and a fourth air hole (25) arranged on the front end face of the nozzle base (10), the side surface of the first flange (20) is abutted against the inner wall of the electrode base (8), a first cooling gas chamber (19) is defined by the upper end surface of the first flange (20), the outer wall of the central gas pipe (4) and the inner wall of the electrode base (8), a first plasma gas chamber (30) is defined by the lower end surface of the first flange (20), the outer wall of the central gas pipe (4) and the inner wall of the electrode base (8), a plurality of gas guide grooves which are communicated with the first cooling gas chamber (19) and the first plasma gas chamber (30) are arranged on the first flange (20) along the axial direction;

a first annular groove and a second annular groove are formed in the outer wall of the electrode base (8), a second flange is formed between the first groove and the second annular groove, the side face of the second flange is abutted to the inner wall of the lower inner insulator (9), a second cooling gas chamber (15) is formed between the first groove and the inner wall of the lower inner insulator (9), a third cooling gas chamber (16) is formed between the inner wall of the nozzle base (10) and the outer wall of the lower inner insulator (9), two ends of the first air hole (18) are communicated with the first cooling gas chamber (19) and the second cooling gas chamber (15), two ends of the third air hole (17) are communicated with the second cooling gas chamber (15) and the third cooling gas chamber (16), and the fourth air hole (25) is communicated with the third cooling gas chamber (16) and the cooling gas channel (27); the second groove and the inner wall of the lower inner insulator (9) form a second plasma gas chamber (22), the second air holes (21) are communicated with the first plasma gas chamber (30) and the second plasma gas chamber (22), a plurality of rotary air grooves are formed in the front end face of the electrode base (8), and the rotary air grooves are communicated with the second plasma gas chamber (22) and the plasma gas channel (26).

2. The plasma arc torch according to claim 1, wherein: the first gas hole (18) has a larger hole diameter than the second gas hole (21), the first cooling gas chamber (19) has a smaller volume than the first plasma gas chamber (30), the first cooling gas chamber (19) has a smaller volume than the second cooling gas chamber (15), the second cooling gas chamber (15) has a smaller volume than the third cooling gas chamber (16), and the first plasma gas chamber (30) has a larger volume than the second plasma gas chamber (22).

3. The plasma arc torch according to any of claims 1-2, wherein: the cutting torch comprises a cutting torch body (13), a copper sleeve and a copper sleeve, wherein the copper sleeve comprises a copper sleeve insulating part (7) and a copper sleeve copper part (6), the copper sleeve insulating part (7) is fixedly connected with the outer wall of a spout base (10) extending out of the cutting torch body (13), one end of the copper sleeve copper part (6) is fixedly connected with the outer wall of the copper sleeve insulating part (7), and the other end of the copper sleeve copper part is fixedly connected with a protective cover (1) through a fixed cover (5).

4. The plasma arc torch of claim 3 wherein: and a first sealing ring (31) is arranged on the connecting surface of the lower inner insulator (9) and the electrode base (8), and a second sealing ring (23) is arranged on the connecting surface of the lower inner insulator (9) and the nozzle base (10).