Economical non-high frequency plasma cutting gun without flow divider

Abstract

The application provides an economic non-high-frequency plasma cutting gun without a shunt, and the gun head is assembled by an inner copper part, an outer copper part, an insulating part, a piston rod, a spring, a sealing ring, an arc leading wire, a cold pressure terminal, a copper gas pipe, a buckle and a nut; the nut, the buckle, the copper gas pipe, the inner copper part and the piston rod are connected as a main circuit negative pole, the cold pressure terminal, the arc leading wire and the outer copper part are connected as an arc leading circuit positive pole, the insulating part is between the outer copper part and the inner copper part, plays an insulating role and is used for isolating the circuit positive pole and the negative pole, and a radial eccentric small hole is arranged at the proximal end of the insulating part, plays a role of replacing the shunt; the vulnerable parts include an electrode, a nozzle, an outer nozzle and a support. The design aims at making the assembly of the whole gun head simpler, the number of parts less and the cost saved, and another aim is that the shunt is not needed to make the gas form a vortex and isolate the electrode and the nozzle, and the vulnerable parts are reduced.

Description

Technical Field

[0001] This invention relates to the field of ion cutting technology, and more specifically, to an economical non-high-frequency plasma cutting gun without a splitter. Background Technology

[0002] Material handling devices such as plasma cutting, flame cutting, and lasers are widely used for cutting and marking workpieces. Plasma cutting typically includes a cutting torch body, an electrode mounted within the body, a nozzle with a central hole, an outer nozzle that holds the nozzle in place, a protective cap to protect the nozzle, electrical connections, channels for cooling and arc control fluids, a distributor to control the fluid flow pattern, and a power supply. The gas used for cutting can be inert or reactive. The plasma arc produced by cutting is a high-temperature, high-velocity ionized jet of converging plasma gas.

[0003] Compared to traditional flame cutting, plasma cutting offers faster speeds, higher efficiency, and better quality for thicknesses less than 25mm. Compared to laser cutting, it shows a significant cost advantage, costing almost one-third of laser cutting, and laser cutting is only suitable for thin plates, limiting its application range. Furthermore, CNC plasma cutting combined with automatic nesting programming software can improve material utilization by 5% to 10%. Based on an annual cutting volume of 20 million tons, this translates to annual savings of 1-2 million tons of steel, worth billions of yuan. Therefore, in industrialized countries, there is a growing trend of replacing flame and laser cutting machines with CNC plasma cutting machines. Thus, researching and promoting plasma cutting technology is of great significance and has a promising future.

[0004] The plasma cutting torches commonly used in the prior art have complex structures. In addition to the parts contained in this application, they also include piston rings, top caps, snap rings, copper braided wires, pins, and other parts. The weight of the raw materials used is also much greater than that of the torches in this application. Moreover, the assembly of commonly used plasma cutting torches is time-consuming and labor-intensive, with many steps. On the other hand, the vulnerable parts of commonly used plasma cutting torches include relatively expensive splitters, resulting in high secondary matching costs. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an economical non-high-frequency plasma cutting gun without a splitter. The gun head uses less material, is simple to assemble, and saves production costs. Furthermore, the gun head of this invention does not have a splitter, a vulnerable component, thus saving on secondary component costs. Another objective is that the gun head of this invention is suitable for both built-in and external gas source cutting machines, making it more widely applicable.

[0006] The technical solution of the present invention is: an economical non-high-frequency plasma cutting gun without a splitter, including a gun head;

[0007] The gun head includes an inner copper component, an outer copper component, an insulating component, a piston rod, a spring, a first sealing ring, a second sealing ring, a third sealing ring, an arc-leading wire, a cold-pressed terminal, a copper air tube, a buckle, and a nut;

[0008] The inner copper component is a shaft-type part; a distal blind hole is machined at the distal end of the inner copper component, and a proximal blind hole is machined at the proximal end of the inner copper component, the distal blind hole being fixedly connected to the copper air pipe; a distal annular groove is machined at the distal end of the inner copper component, and a proximal annular groove is machined at the proximal end of the inner copper component; multiple radial holes of the inner copper component are machined around the inner circumference of the distal annular groove, the radial holes of the inner copper component communicating with the distal blind hole; multiple axial inner copper component keyways are also machined on the outer circular surface of the inner copper component, one end of the inner copper component keyway connecting to the distal annular groove, and the other end connecting to the proximal annular groove.

[0009] The proximal blind hole is a stepped blind hole, forming three sections of holes with different diameters: a small diameter hole, a medium diameter hole, and a large diameter hole. The transition step surface between the small diameter hole and the medium diameter hole is the first step surface, and the transition step surface between the medium diameter hole and the large diameter hole is the second step surface. There are one or more axially connected vent holes for the inner copper component between the first step surface and the distal end face of the inner copper component. The vent holes for the inner copper component do not interfere with the radial small hole.

[0010] The piston rod is a shaft-like part with a central through hole. The piston rod has three outer circular surfaces of different diameters, from farthest to near: a small diameter surface, a medium diameter surface, and a large diameter surface. A third step surface is formed by the transition between the medium and large diameter surfaces. A radial through hole is located on the medium diameter surface, communicating with the central through hole. A flange is located on the proximal outer surface of the large diameter surface, and a second O-ring groove is present on the flange, capable of accommodating a second sealing ring.

[0011] The piston rod can be inserted into the proximal blind hole of the inner copper component from the proximal end of the inner copper component. The small-diameter hole can accommodate the distal small-diameter surface of the piston rod, the medium-diameter hole can accommodate the large-diameter surface of the piston rod, and the large-diameter hole can accommodate the outer circular surface of the flange of the piston rod and is sealed with the large-diameter hole of the inner copper component by a second sealing ring. A spring is sleeved on the outer periphery of the medium-diameter surface. The spring is a compression spring and is constrained by the inner copper component and the piston rod. One end of the spring is constrained by the third step surface of the piston rod, and the other end is constrained by the first step surface of the inner copper component, so that the piston rod can reciprocate axially within the proximal blind hole of the inner copper component.

[0012] The insulating component is a cylindrical part. A step is machined near the proximal end of the insulating component's inner hole. The inner copper component can be inserted into the inner hole of the insulating component from its distal end, and its proximal end face is constrained by the step. A first air chamber is formed between the distal annular groove and the inner hole wall of the insulating component, and a second air chamber is formed between the proximal annular groove and the inner hole wall of the insulating component. Below the proximal annular groove is a first O-ring groove, which can accommodate a first sealing ring and is sealed to the insulating component by the first sealing ring. A first thread is present on the distal outer surface of the inner copper component, and the distal end of the inner copper component is connected to the insulating component via the first thread.

[0013] The insulating component has multiple radial holes machined along the circumferential direction at the middle section, and these radial holes communicate with the second air chamber; the outer surface of the near end of the insulating component has a third O-ring groove, which can accommodate a third sealing ring; the insulating component between the third O-ring groove and the radial holes has multiple radially eccentric holes machined along the circumferential direction.

[0014] The outer copper component is a cylindrical part. An inner annular groove is machined in the middle of the inner hole of the outer copper component. Multiple axial holes are machined on the outer copper component between the inner annular groove and the near end face of the outer copper component. The outer copper component is fixedly connected to the outside of the insulating component. A third air chamber is formed between the inner annular groove of the outer copper component and the outer wall of the insulating component. The radial holes and radial eccentric holes of the insulating component are connected to the third air chamber. The bottom of the insulating component is sealed to the inner wall of the outer copper component through a third sealing ring.

[0015] The distal end face of the outer copper part has an axially eccentric blind hole that connects to the arc-leading line.

[0016] Furthermore, it also includes consumable parts; the consumable parts include electrodes, nozzles, external nozzles, and supports;

[0017] The electrode is a shaft-type part, with the distal end of the electrode inserted into the proximal end of the central through hole of the piston rod, and a radioactive element provided at the proximal end of the electrode.

[0018] The outer circumferential surface of the distal end of the nozzle is fixedly connected to the proximal end of the inner hole of the outer copper part. The nozzle has a nozzle center hole inside to accommodate the electrode, and there is a certain gap between the nozzle center hole and the outer diameter of the electrode. The gap is the fourth gas chamber. The fourth gas chamber and the third gas chamber are connected by the radial eccentric small hole of the insulating part. The nozzle center hole and the nozzle proximal end face are machined with nozzle small holes.

[0019] The inner surface of the outer nozzle is fixedly connected to the near-end outer surface of the outer copper component;

[0020] The inner hole of the bracket is slightly smaller than the outer diameter of the outer nozzle and has a slit on the side, so that the bracket can clamp the outer nozzle; the bracket has two symmetrical legs at the proximal end, and the distance between the proximal end face of the legs and the proximal end face of the nozzle is 0.5mm to 2mm.

[0021] Furthermore, the multiple axial holes on the outer copper component are distributed on two circumferences of different diameters;

[0022] The near end of the inner hole of the outer copper part is fixedly connected to the outer circumferential surface of the far end of the nozzle. A fourth step surface is also machined on the outer circumference of the far end of the nozzle, and the fourth step surface is pressed into contact with the near end surface of the outer copper part.

[0023] The fourth step surface has two diameter specifications. When the fourth step surface does not block all the axial small holes of the outer copper parts, the nozzle is an external air nozzle with a relatively large air output from the nozzle orifice. When the fourth step surface blocks the axial small holes of the outer copper parts in the inner ring of the outer copper parts but does not block the axial small holes of the outer copper parts in the outer ring of the outer copper parts, the nozzle is an internal air nozzle with a relatively small air output from the nozzle orifice.

[0024] Furthermore, the piston rod has a conical hole near its central through hole, with the angle of the conical hole ranging from 0 to 90 degrees.

[0025] The electrode is a shaft-like part made of conductive material. The distal surface of the electrode is machined into a tapered shape and inserted into a conical hole near the central through hole of the piston rod. A emitting element is provided near the electrode.

[0026] Furthermore, the proximal end hole of the piston rod is a threaded hole, which is threadedly connected to the distal end of the electrode. At this time, the bottom of the stepped blind hole of the inner copper part is a waist-shaped groove, and there is a pin hole at the distal end of the piston rod. A pin is installed in the pin hole. The length of the pin is less than the length of the waist-shaped groove, and the diameter is less than the width of the waist-shaped groove. When the piston rod slides axially, the pin and the waist-shaped groove can restrict its rotation.

[0027] Furthermore, the proximal end hole of the piston rod is a stepped straight hole, and a crown spring is accommodated inside the stepped straight hole and connected to the electrode.

[0028] Furthermore, the proximal end hole of the piston rod is a stepped straight hole, and a drum spring is installed at the distal end of the electrode. The stepped straight hole compresses the drum spring to allow the electrode to engage.

[0029] Furthermore, the distal small-diameter surface of the piston rod and the small-diameter hole of the inner copper component are clearance fits, with a clearance size between 0 mm and 0.1 mm; the large-diameter surface of the piston rod and the middle-diameter hole of the inner copper component are clearance fits, with a clearance size between 0 mm and 0.1 mm.

[0030] Furthermore, one end of the arc-leading wire is connected to an eccentric blind hole on the axial direction of the distal end face of the outer copper component. This connection can be achieved by crimping or welding. The arc-leading wire has a copper conductor inside and an insulating sheath on the outside.

[0031] Furthermore, the cold-pressed terminal is crimped to the other end of the arc-leading wire.

[0032] Furthermore, the copper gas pipe is a tubular copper part, one end of which is connected to the distal threaded blind hole of the inner copper part, and the connection position does not exceed the radial small hole of the inner copper part.

[0033] Furthermore, the buckle is a copper part that fits onto the copper gas pipe to provide a sealing and fixing function.

[0034] Furthermore, the nut is a copper part that is fitted onto the copper gas pipe to connect to the cable.

[0035] The beneficial effects of this invention are: it provides an economical non-high-frequency plasma cutting gun without a splitter. The non-high-frequency plasma cutting gun head is assembled from an inner copper part, an outer copper part, an insulating part, a piston rod, a spring, a sealing ring, an arc-starting wire, a cold-pressed terminal, a copper gas pipe, a buckle, and a nut. The nut, buckle, copper gas pipe, inner copper part, and piston rod are connected to the negative terminal of the main circuit, and the cold-pressed terminal, arc-starting wire, and outer copper part are connected to the positive terminal of the arc-starting circuit. The insulating part is located between the outer copper part and the inner copper part, serving as insulation to isolate the positive and negative terminals of the circuit. The insulating part has a radially eccentric small hole near its proximal end, which acts as a substitute for a splitter. The spring is located between the piston rod and the inner copper part and is compressed by both, enabling the piston rod to achieve axial reciprocating motion. The sealing ring serves as a gas path seal in the entire design. The outer copper part has multiple axial small holes of different diameters. The vulnerable parts include an electrode, a nozzle, an outer nozzle, and a bracket. The purpose of this design is to simplify the assembly of the entire gun head, reduce the number of parts, and save costs; another purpose is to eliminate the need for a flow divider to create gas vortices and to isolate the electrode and nozzle, thus reducing vulnerable parts; yet another purpose is that the gun head of this invention is suitable for both built-in and external gas source cutting machines, making it more widely applicable. Attached Figure Description

[0036] Figure 1 This is a cross-sectional view of the main components of the plasma cutting torch head using the present invention.

[0037] Figure 2 This is a cross-sectional view of the plasma cutting torch head and consumable parts using the present invention.

[0038] Figure 3 This is a schematic diagram of gas flow when using the plasma cutting torch head of the present invention.

[0039] Figure 4 A diagram showing the connection position of the arc-leading wire using the present invention.

[0040] Figure 5 This is a comparison diagram showing the use of the built-in air nozzle (left side) and the external air nozzle (right side) when applying the present invention.

[0041] Figure 6 This is another example of using the piston rod of the present invention.

[0042] Figure 7 This is another example of using the piston rod of the present invention.

[0043] Figure 8 This is another example of using the piston rod of the present invention.

[0044] in:

[0045] 1-Inner copper component 2-Insulating component 3-Piston rod

[0046] 4-Outer copper part; 5-Outer nozzle; 6-Electrode

[0047] 7-Nozzle 8-Bracket 9-First Sealing Ring

[0048] 10-Second sealing ring; 11-Third sealing ring; 12-Cold-pressed terminal

[0049] 13-Arc guide wire 14-Snap fastener 15-Nut

[0050] 16-Spring 17-Copper air tube 18-Inner hole of copper air tube

[0051] 19-Radial small hole of inner copper component; 20-First air chamber; 21-Keyway of inner copper component

[0052] 22-Second chamber; 23-Radial small hole of insulating component; 24-Third chamber

[0053] 25-Axial small hole of outer copper part; 26-Radial eccentric small hole of insulating part; 27-Fourth air chamber

[0054] 28- Nozzle orifice; 29- Piston rod center through hole; 30- Piston rod radial through hole

[0055] 31-Inner copper component vent hole; 32-Outer copper component distal blind hole; 33-Crown spring

[0056] 34-Drum spring; 35-Pin; 7.1-External air nozzle

[0057] 7.2-Built-in air nozzle 101-Proximal step of inner copper component 102-Waist-shaped groove of inner copper component

[0058] 201 - Insulating component inner hole step; 301 - Piston rod tapered hole; 302 - Piston rod threaded hole

[0059] 303 - Piston rod pin hole; 401 - External copper part near end internal thread; 701 - Nozzle step Detailed Implementation

[0060] Example 1

[0061] The plasma cutting torch head of the present invention will be further described in detail with reference to the accompanying drawings.

[0062] The plasma cutting torch of this invention is an economical non-high-frequency plasma cutting torch without a splitter. Its vulnerable parts do not require the use of a splitter, making it economical and practical, and reducing the cost of secondary accessories.

[0063] like Figures 1 to 5 As shown, an economical non-high-frequency plasma cutting torch head without a splitter and its consumable parts are disclosed, including the torch head and consumable parts.

[0064] The gun head includes an inner copper component 1, an insulating component 2, a piston rod 3, an outer copper component 4, a spring 16, a first sealing ring 9, a second sealing ring 10, a third sealing ring 11, an arc-leading wire 13, a cold-pressed terminal 12, a copper air tube 17, a buckle 14, and a nut 15; the vulnerable components include an electrode 6, a nozzle 7, an outer nozzle 5, and a bracket 8.

[0065] The blind hole at the proximal end of the inner copper component 1 accommodates the piston rod 3 and compresses the spring 16 between the inner copper component 1 and the piston rod (3); the blind hole at the distal end of the inner copper component 1 is threadedly connected to the copper gas pipe 17, serving as the inlet for plasma gas; the inner copper component 1 and the insulating component 2 are threadedly connected, and the assembly position of the inner copper component 1 is restricted by the inner hole step 201 of the insulating component 2; the insulating component 2 and the outer copper component 4 are threadedly connected, and the assembly position of the insulating component 2 is restricted by the distal end face of the outer copper component 4; the piston rod 3 can... The inner copper component 1 slides axially within the stepped blind hole. The maximum upward displacement is determined by the near-end step 101 of the inner copper component, i.e., the second step surface, and the maximum downward position is determined by the inner hole step 201 of the insulating component. The copper gas pipe 17 is fitted with the buckle 14 and the nut 15 for connecting the main cable and the gas pipe of the plasma cutting gun. The arc-starting wire 13 is connected to the far-end blind hole 32 of the outer copper component 2, which can be crimped or welded. The cold-pressed terminal 12 is crimped to the other end of the arc-starting wire 13 for connecting the arc-starting cable of the plasma cutting gun.

[0066] The inner copper component 1 has multiple radially distributed small holes 19, which communicate with the distal blind hole. The other end of each radially distributed small hole 19 forms a distal annular groove in the inner copper component 1. A first air chamber 20 is formed between the distal annular groove and the insulating component 2. The inner copper component 1 also has a proximal annular groove, which forms a second air chamber 22 with the insulating component 2. Connecting the first air chamber 20 and the second air chamber 22 is an inner copper component keyway 21, which is evenly distributed on the outer circumferential surface of the inner copper component 1. The insulating component 2 has multiple radially distributed small holes 23. The outer copper component 4 has an annular groove located in the middle of its inner hole. The groove and the outer wall of the insulating component form a third gas chamber 24. The radial small hole 23 of the insulating component connects the second gas chamber 22 and the third gas chamber 24. The annular groove of the inner hole of the inner copper component 4 connects to the near end face of the inner copper component 4 and multiple circumferentially distributed axial small holes 25. The axial small holes 25 are distributed on two circumferences of different diameters. The inner copper component 1 is equipped with a first sealing ring 9, which seals with the inner wall of the insulating component 2 to prevent plasma gas leakage. The piston rod 3 is equipped with a second sealing ring 10, which seals with the inner wall of the near end blind hole of the inner copper component 1 to prevent plasma gas leakage. The insulating component 2 is equipped with a third sealing ring 11, which seals with the inner wall of the outer copper component 4 to prevent plasma gas leakage.

[0067] After the vulnerable parts are installed, the distal conical surface of the electrode 6 mates with the tapered hole 301 of the piston rod 3. The nozzle 7 is connected to the proximal internal thread 401 of the outer copper part 4 via a thread, and the assembly position is restricted by the step 701 of the nozzle 7. The step 701 has two specifications: when the step 701 does not obstruct all axial small holes of the outer copper part 4, the nozzle is an external air nozzle 7.1; when the step 701 obstructs the axial small holes of the inner ring of the outer copper part 4 but does not obstruct the axial small holes of the outer ring of the outer copper part 4, the nozzle is an internal air nozzle 7.2. The inner hole of the nozzle 7 accommodates the electrode 6 with a certain gap, which is the fourth air chamber 27. The fourth air chamber 27 and the third air chamber 24 are connected by the radially eccentric small hole 26 of the insulating component. The proximal end face of the nozzle 7 is connected to the nozzle small hole 28 through the inner hole accommodating the electrode 6. The outer nozzle 5 is made of cylindrical ceramic material and is connected to the outer copper component 4 by threads. The bracket 8 is clamped to the outer circle of the outer nozzle 5. After assembly, the distance between the proximal end face of the bracket 8 and the proximal end face of the nozzle 7 is between 0.1 mm and 2 mm.

[0068] The negative terminal of the main circuit passes through the nut 15, copper gas pipe 17, inner copper component 1, piston rod 3, and electrode 6. The positive terminal of the arc-starting circuit passes through the cold-pressed terminal 12, arc-starting wire 13, outer copper component 4, and nozzle 7. Initially, electrode 6 and nozzle 7 are in contact. When gas and electricity are supplied, plasma gas flows into the first gas chamber 20 through the inner hole 18 of the copper gas pipe and the radial small hole 19 of the inner copper component. Then, it flows into the second gas chamber 22 through the keyway 21 of the inner copper component, and then into the third gas chamber 24 through the radial small hole 23 of the insulating component. Part of the gas flows into the fourth gas chamber 27 through the radial eccentric small hole 26 of the insulating component, and is then blown out through the small hole 28 of the nozzle. This is cutting gas. At the same time, the gas will push the piston rod 3 upward axially. At this time, since the central through hole 29 and the radial through hole 30 of the piston rod are connected to the exhaust hole 31 of the inner copper component to the outside atmosphere, a negative pressure is formed on the electrode 6, causing it to rise axially along with the piston rod 3. Another part of the gas is blown out through the axial small hole 25 of the outer copper component. This is cooling gas. When the electrode 6 and the nozzle 7 are energized, they ignite. The plasma gas causes the electrode 6 to rise at the moment of ignition, forming an arc. The gas blown out by the nozzle 7 then blows out the plasma arc, completing the arc ignition.

[0069] Example 2

[0070] like Figure 6 As shown, the proximal hole of the piston rod 3 is a threaded hole 302, which is threadedly connected to the electrode 6. At this time, the bottom of the stepped blind hole of the inner copper part is a waist-shaped groove 102. Meanwhile, there is a pin hole 303 at the far end of the piston rod 3, and a pin 3 is installed on the pin hole 303. The length of the pin 35 is less than the length of the waist-shaped groove 102, and the diameter is less than the width of the waist-shaped groove 102. When the piston rod 3 slides axially, the pin 35 and the waist-shaped groove 102 can restrict its rotation.

[0071] Example 3

[0072] like Figure 7 As shown, the proximal hole of the piston rod 3 is a stepped straight hole, and a crown spring 33 is accommodated inside the stepped straight hole to cooperate with the electrode 6.

[0073] Example 4

[0074] like Figure 8 As shown, the proximal hole of the piston rod 3 is a stepped straight hole, and a drum spring 34 is installed at the distal end of the electrode 6. The stepped straight hole compresses the drum spring 34 to allow the electrode 6 to engage.

[0075] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An economical non-high-frequency plasma cutting torch without a splitter, characterized in that: Including the gun head; The gun head includes an inner copper component, an outer copper component, an insulating component, a piston rod, a spring, a first sealing ring, a second sealing ring, a third sealing ring, an arc-leading wire, a cold-pressed terminal, a copper air tube, a buckle, and a nut; The inner copper component is a shaft-type part; a distal blind hole is machined at the distal end of the inner copper component, and a proximal blind hole is machined at the proximal end of the inner copper component, the distal blind hole being fixedly connected to the copper air pipe; a distal annular groove is machined at the distal end of the inner copper component, and a proximal annular groove is machined at the proximal end of the inner copper component; multiple radial holes of the inner copper component are machined around the inner circumference of the distal annular groove, the radial holes of the inner copper component communicating with the distal blind hole; multiple axial inner copper component keyways are also machined on the outer circular surface of the inner copper component, one end of the inner copper component keyway connecting to the distal annular groove, and the other end connecting to the proximal annular groove. The proximal blind hole is a stepped blind hole, forming three sections of holes with different diameters: a small diameter hole, a medium diameter hole, and a large diameter hole. The transition step surface between the small diameter hole and the medium diameter hole is the first step surface, and the transition step surface between the medium diameter hole and the large diameter hole is the second step surface. There are one or more axially connected vent holes for the inner copper component between the first step surface and the distal end face of the inner copper component. The vent holes for the inner copper component do not interfere with the radial small hole. The piston rod is a shaft-like part with a central through hole. The piston rod has three outer circular surfaces of different diameters, from farthest to near: a small diameter surface, a medium diameter surface, and a large diameter surface. A third step surface is formed by the transition between the medium and large diameter surfaces. A radial through hole is located on the medium diameter surface, communicating with the central through hole. A flange is located on the proximal outer surface of the large diameter surface, and a second O-ring groove is present on the flange, capable of accommodating a second sealing ring. The piston rod can be inserted into the proximal blind hole of the inner copper component from the proximal end of the inner copper component. The small-diameter hole can accommodate the distal small-diameter surface of the piston rod, the medium-diameter hole can accommodate the large-diameter surface of the piston rod, and the large-diameter hole can accommodate the outer circular surface of the flange of the piston rod and is sealed with the large-diameter hole of the inner copper component by a second sealing ring. A spring is sleeved on the outer periphery of the medium-diameter surface. The spring is a compression spring and is constrained by the inner copper component and the piston rod. One end of the spring is constrained by the third step surface of the piston rod, and the other end is constrained by the first step surface of the inner copper component, so that the piston rod can reciprocate axially within the proximal blind hole of the inner copper component. The insulating component is a cylindrical part. A step is machined near the proximal end of the insulating component's inner hole. The inner copper component can be inserted into the inner hole of the insulating component from its distal end, and its proximal end face is constrained by the step. A first air chamber is formed between the distal annular groove and the inner hole wall of the insulating component, and a second air chamber is formed between the proximal annular groove and the inner hole wall of the insulating component. Below the proximal annular groove is a first O-ring groove, which can accommodate a first sealing ring and is sealed to the insulating component by the first sealing ring. A first thread is present on the distal outer surface of the inner copper component, and the distal end of the inner copper component is connected to the insulating component via the first thread. The insulating component has multiple radial holes machined along the circumferential direction at the middle section, and these radial holes communicate with the second air chamber; the outer surface of the near end of the insulating component has a third O-ring groove, which can accommodate a third sealing ring; the insulating component between the third O-ring groove and the radial holes has multiple radially eccentric holes machined along the circumferential direction. The outer copper component is a cylindrical part. An inner annular groove is machined in the middle of the inner hole of the outer copper component. Multiple axial holes are machined on the outer copper component between the inner annular groove and the near end face of the outer copper component. The outer copper component is fixedly connected to the outside of the insulating component. A third air chamber is formed between the inner annular groove of the outer copper component and the outer wall of the insulating component. The radial holes and radial eccentric holes of the insulating component are connected to the third air chamber. The bottom of the insulating component is sealed to the inner wall of the outer copper component through a third sealing ring. The distal end face of the outer copper part has an axially eccentric blind hole that connects to the arc-leading line.

2. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: It also includes consumable parts; the consumable parts include electrodes, nozzles, external nozzles, and supports; The electrode is a shaft-type part, with the distal end of the electrode inserted into the proximal end of the central through hole of the piston rod, and a radioactive element provided at the proximal end of the electrode. The outer circumferential surface of the distal end of the nozzle is fixedly connected to the proximal end of the inner hole of the outer copper part. The nozzle has a nozzle center hole inside to accommodate the electrode, and there is a certain gap between the nozzle center hole and the outer diameter of the electrode. The gap is the fourth gas chamber. The fourth gas chamber and the third gas chamber are connected by the radial eccentric small hole of the insulating part. The nozzle center hole and the nozzle proximal end face are machined with nozzle small holes. The inner surface of the outer nozzle is fixedly connected to the near-end outer surface of the outer copper component; The inner hole of the bracket is slightly smaller than the outer diameter of the outer nozzle and has a slit on the side, so that the bracket can clamp the outer nozzle; the bracket has two symmetrical legs at the proximal end, and the distance between the proximal end face of the legs and the proximal end face of the nozzle is 0.5mm to 2mm.

3. A shunt-free, economical non-high-frequency plasma cutting torch according to claim 1 or 2, characterized in that: The multiple axial holes on the outer copper component are distributed on two circumferences of different diameters. The near end of the inner hole of the outer copper part is fixedly connected to the outer circumferential surface of the far end of the nozzle. A fourth step surface is also machined on the outer circumference of the far end of the nozzle, and the fourth step surface is pressed into contact with the near end surface of the outer copper part. The fourth step surface has two diameter specifications. When the fourth step surface does not block all the axial small holes of the outer copper parts, the nozzle is an external air nozzle; when the fourth step surface blocks the axial small holes of the outer copper parts in the inner ring of the outer copper parts but does not block the axial small holes of the outer copper parts in the outer ring of the outer copper parts, the nozzle is an internal air nozzle.

4. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: The piston rod has a conical hole near its central through hole, with the angle of the conical hole ranging from 0 to 90 degrees. The electrode is a shaft-like part made of conductive material. The distal surface of the electrode is machined into a tapered shape and inserted into a conical hole near the central through hole of the piston rod. A emitting element is provided near the electrode.

5. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: The proximal end hole of the piston rod is a threaded hole, which is threaded to the distal end of the electrode. At this time, the bottom of the stepped blind hole of the inner copper part is a waist-shaped groove. At the same time, there is a pin hole at the distal end of the piston rod, and a pin is installed in the pin hole. The length of the pin is less than the length of the waist-shaped groove, and the diameter is less than the width of the waist-shaped groove. When the piston rod slides axially, the pin and the waist-shaped groove can restrict its rotation.

6. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: The proximal end hole of the piston rod is a stepped straight hole, and a crown spring is accommodated inside the stepped straight hole and connected to the electrode.

7. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: The piston rod has a stepped straight hole at its proximal end, and a drum spring is installed at the distal end of the electrode. The stepped straight hole compresses the drum spring to allow the electrode to engage.

8. The economical non-high-frequency plasma cutting torch without a splitter according to claim 1, characterized in that: The distal small-diameter surface of the piston rod and the small-diameter hole of the inner copper component are clearance fit, with a clearance size between 0 mm and 0.1 mm; the large-diameter surface of the piston rod and the middle-diameter hole of the inner copper component are clearance fit, with a clearance size between 0 mm and 0.1 mm.

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