Plasma arc torch

Abstract

The application discloses a kind of plasma arc welding torch, to solve the technical problems of poor cooling effect of existing welding torch, nozzle disassembly and maintenance are complicated, tungsten needle is low, the service life of gun body is short.It includes gun body assembly and the gun head assembly detachably mounted on gun body assembly, tungsten needle, centering device, nozzle, tungsten needle limiting component and cooling waterway component are arranged in gun head assembly;Cooling waterway component constructs independent negative electrode, positive electrode double cooling waterway, adopts sectional type surrounding flow channel design;Nozzle is provided with annular positioning boss, and forms two-stage coaxial limiting system with centering device, gun body assembly integrates independent ion gas, double gas path structure of shielding gas, and the tail of gun adopts integrated linkage quick-release structure.The application greatly improves the cooling efficiency of welding torch and the centering accuracy of tungsten needle under the premise of ensuring compact structure, realizes quick disassembly and maintenance of wearing parts, effectively prolongs the service life of welding torch, and can be widely adapted to various high-load continuous welding industrial scenes.

Description

Technical Field

[0001] This invention relates to the field of arc welding equipment technology, and more specifically to a plasma arc welding torch. Background Technology

[0002] With the continuous development of welding manufacturing technology, plasma arc welding torches, with their advantages of concentrated arc energy, small welding deformation, and excellent forming quality, are widely used in precision welding, hardware processing, pressure vessels, and aerospace industries. The cooling efficiency of the welding torch directly determines welding stability, weld quality, and the overall service life of the equipment. The rationality of the cooling channel's structural design is a core factor affecting the cooling effect. However, the existing conventional plasma arc welding torch cooling channel design has significant limitations. The narrow cooling channels result in mediocre cooling effects, making it difficult to meet the needs of long-term continuous welding operations. This pain point has become a key bottleneck restricting welding efficiency and torch durability.

[0003] Chinese Patent Publication No. CN105537743B discloses a micro-beam plasma arc welding torch. This design achieves stable arc operation under low current conditions by optimizing the upper and lower torch body cooling water channel structure, setting a coaxial positioning mechanism, and a convergent nozzle structure. Simultaneously, it enhances the molten pool protection effect through multi-stage gas channels. However, like most existing arc welding torches, this plasma arc welding torch is limited by its overall outer diameter, multi-layer component assembly, and insulation sealing requirements. This results in the cooling water channel being a narrow annular gap naturally formed after the components are assembled, with the radial gap forced to be compressed to a minimum, forming a long, thin-slit cooling channel. Furthermore, since most components are fixedly assembled, the cooling channel cannot be disassembled for cleaning. After long-term use, scale easily accumulates in the flow channel, further reducing the flow cross-section, leading to a slowdown in cooling water flow rate and a decrease in cooling effect. This makes it unsuitable for long-term continuous welding operations and significantly falls short of the current requirements for high-performance welding torches.

[0004] In summary, existing plasma arc welding torches generally suffer from the technical defect of narrow cooling channels, resulting in poor circulation of the cooling medium, low heat exchange efficiency, and mediocre cooling effect. They are unable to quickly remove the heat from the high-temperature components of the welding torch, and long-term use can easily lead to problems such as high-temperature deformation and burn-out of the nozzle, affecting the service life and welding stability of the welding torch. They are unable to meet the needs of long-term continuous welding operations and cannot achieve the high-efficiency cooling and durability performance standards achieved by the SP1000 plasma welding torch (an industrial plasma welding torch with a rated current of 1000A).

[0005] Therefore, developing a plasma arc welding torch with optimized cooling channel structure, increased cooling channel gap, and improved cooling effect is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of narrow cooling channels, poor centering, inconvenient disassembly and assembly, and short lifespan of existing welding torches, and to provide a plasma arc welding torch that is highly efficient in cooling, accurate in centering, and easy to maintain.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions:

[0008] A plasma arc welding torch includes: a torch body assembly 100 and a torch head assembly 1 detachably mounted on the torch body assembly 100. The torch head assembly 1 includes: a tungsten needle 2, a centering device 3, and a nozzle 4. The tungsten needle 2 is disposed at the central axis inside the torch head assembly 1. The centering device 3 is coaxially sleeved on the outer side of the lower end of the tungsten needle 2. The nozzle 4 is detachably connected to the bottom of the torch head assembly 1. The nozzle 4 has a nesting groove 41 inside, and an inwardly protruding annular positioning boss 42 is coaxially disposed at the center of the nesting groove 41. The lower end of the centering device 3 is embedded in the annular positioning boss 42. A tungsten needle limiting component 5 for fixing the tungsten needle 2 is also coaxially sleeved on the outer side of the tungsten needle 2. The torch head assembly 1 also includes a cooling water channel assembly, which includes a lower water guide sleeve 61, an outer water guide sleeve 62, and a water seal head 63. The lower water guide sleeve 61 is coaxially sleeved on the outside of the centering device 3, and the lower part of the lower water guide sleeve 61 extends into the nested groove 41 of the nozzle 4; the outer water guide sleeve 62 is coaxially sleeved on the outside of the nozzle 4 and the water seal head 63, and the outer water guide sleeve 62 has a first annular protrusion 621 protruding on its inner sidewall, and the water seal head 63 is detachably embedded in the interior of the outer water guide sleeve 62 through the first annular protrusion 621; the gun head assembly 1 is provided with at least a first water inlet 101 for negative electrode cooling water to enter and a second water inlet 102 for positive electrode cooling water to enter; a negative electrode cooling water passage 64 is formed between the water seal head 63, the outside of the tungsten needle limiting assembly 5, and the inner wall of the gun body assembly 100, which communicates with the first water inlet 101; a positive electrode cooling water passage 65 is formed between the water seal head 63, the nozzle 4, the lower water guide sleeve 61, and the outer water guide sleeve 62, which communicates with the second water inlet 102.

[0009] Preferably, the negative electrode cooling water path 64 includes a first annular cooling water channel 641 that communicates with the first inlet 101 and is formed between the top of the water seal head 63, the outside of the tungsten needle limiting component 5, and the inside of the gun body assembly 100, and a first cooling water channel 642 that communicates with the first annular cooling water channel 641 and is disposed between the inner sidewall of the water seal head 63 and the outside of the tungsten needle limiting component 5; the positive electrode cooling water path 65 includes a second annular cooling water channel 651 that is formed between the top of the outer water guide sleeve 62, the outside of the water seal head 63, and the inside of the gun body assembly 100 and communicates with the second inlet 102, a second cooling water channel 652 that is formed between the outer sidewall of the water seal head 63 and the inner sidewall of the outer water guide sleeve 62, and a third cooling water channel 653 that communicates with the second cooling water channel 652 and is formed between the inner sidewall of the nested groove 41 and the outer sidewall of the lower water guide sleeve 61.

[0010] Preferably, the nozzle 4 is detachably connected to the inner thread of the outer water guide sleeve 62 via an external thread; the lowermost end face of the nozzle 4 is provided with a positioning hole 43 for inserting an external tool.

[0011] Preferably, the tungsten needle limiting assembly 5 includes, from the inside to the outside: a tungsten needle clamp 51, a tungsten needle clamp tension spring 52, and a tungsten needle clamp sleeve 53; the tungsten needle clamp 51 is coaxially sleeved on the upper half of the outer side of the tungsten needle 2, and the tungsten needle clamp 51 has an elastic clamp head 510 at its lower end; the tungsten needle clamp tension spring 52 is coaxially sleeved on the outer side of the elastic clamp head 510 to provide pre-tightening force; the tungsten needle clamp 51 is limited and embedded inside the tungsten needle clamp sleeve 53.

[0012] Preferably, an isolation ring 54 is provided between the top of the lower water guide sleeve 61 and the bottom of the tungsten needle clamp sleeve 53. The isolation ring 54 is coaxially sleeved on the outer side of the lower end of the tungsten needle clamp sleeve 53 and abuts against the lower water guide sleeve 61.

[0013] Preferably, the gun head assembly 1 further includes a gun tail assembly 7 disposed at the top of the gun body assembly 100. The gun tail assembly 7 includes a gun cap 71, a retaining ring 72, a gun tail copper core 73, and a gun tail copper sleeve 74. The gun tail copper core 73 is coaxially disposed at the inner center of the gun tail copper sleeve 74, and its lower end is sleeved and connected to the top of the tungsten needle clip 51. The gun tail copper sleeve 74 is coaxially disposed on the outside of the gun tail copper core 73. The gun cap 71 is coaxially fastened to the outside of the gun tail copper sleeve 74. The retaining ring 72 is coaxially snapped onto the outer periphery of the top of the gun tail copper core 73 and abuts against the top wall of the gun tail copper sleeve 74.

[0014] Preferably, the annular positioning boss 42 of the nozzle 4 has a channel 420 in the middle, and the tip of the tungsten needle 2 passes through the centering device 3 and extends into the channel 420 of the nozzle 4 without extending out of the nozzle 4; the lower end of the centering device 3 is embedded in the annular positioning boss 42.

[0015] Preferably, the gun head assembly 1 includes: an ion gas body 11, an insulating pad 12, a protective gas body 13, and a protective sleeve 14; the ion gas body 11 is coaxially sleeved on the outside of the tungsten needle limiting assembly 5, and is provided with a first air inlet 111 for ion gas to enter and a first water inlet 101; the protective gas body 13 is coaxially sleeved on the outside of the outer water guide sleeve 62, and is provided with a second air inlet 131 for protective gas to enter and a second water inlet 102; the insulating pad 12 is connected between the ion gas body 11 and the protective gas body 13; the protective sleeve 14 is used to surround the ion gas body 11, the insulating pad 12, and the protective gas body 13, and is provided inside with pipes that are respectively connected to the first air inlet 111, the first water inlet 101, the second air inlet 131, and the second water inlet 102. Specifically, the protective sleeve 14 includes an upper surrounding structure 141 that surrounds the upper periphery of the ionizing gas body 11 and a lower surrounding structure 142 that surrounds the lower part of the ionizing gas body 11, the insulating pad 12, and the protective gas body 13. In addition, one or more sealing rings 200 are embedded between the ionizing gas body 11 and the insulating pad 12, and between the insulating pad 12 and the protective gas body 13.

[0016] Preferably, the outer water guide sleeve 62 is coaxially fitted with a side diffuser 81 and a uniform diffuser 82 distributed vertically; the side diffuser 81 is coaxially fitted with an adapter sleeve 83, and the adapter sleeve 83 is threadedly connected to a copper sleeve 84, which is located outside the nozzle 4.

[0017] Preferably, one or more sealing rings 200 are embedded between the nozzle 4 and the lower water guide sleeve 61, the nozzle 4 and the outer water guide sleeve 62, the lower water guide sleeve 61 and the water seal head 63, the water seal head 63 and the tungsten needle limiting assembly 5, and the inner and outer connections of the outer water guide sleeve 62 and the gun body assembly 100; a flat rubber gasket 9 is embedded between the upper and lower connections of the gun body assembly 100 and the water seal head 63.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This design utilizes a detachable gun body assembly and gun head assembly, allowing for separate disassembly and maintenance of the gun head assembly without disassembling the entire gun, thus enhancing ease of use. Furthermore, the detachable mounting structure of the water seal head and outer water guide sleeve, along with the detachable mounting structure of the nested groove between the lower water guide sleeve and the nozzle, enables flexible disassembly of each component. This facilitates direct removal for cleaning the inner walls of the cooling channels, eliminating scale and impurities, and ensuring optimal cooling performance. Furthermore, addressing the issue of narrow cooling channels in existing technologies, this invention, without increasing the overall dimensions of the gun body and ensuring a compact structure, achieves axial limiting and embedding of the water seal head through a first annular protrusion on the inner side of the outer water guide sleeve. Without altering the outer diameter of the outer water guide sleeve, a uniform and controllable annular water passage gap is pre-reserved between the outer wall of the water seal head and the inner wall of the outer water guide sleeve. This annular water passage gap is larger than the passively formed assembly gap in existing technologies, resulting in better cooling performance. Moreover, the lower end of the lower water guide sleeve extends into the nested groove inside the nozzle. While ensuring the radial limiting strength of the centering device and without increasing the outer diameter of the nozzle, a continuous annular water passage cavity is formed between the outer wall of the lower water guide sleeve and the inner wall of the nozzle nested groove. The annular water passage gap is larger than the passively formed assembly gap in existing technologies, further improving the cooling effect. Through the above-mentioned arrangement, the cavity structure design with nested grooves inside the nozzle, combined with the detachable water circuit components, optimizes the water cooling channel shape within a limited radial space, reduces the dead water area, increases the effective water flow cross-sectional area, and improves the cooling water circulation throughput and heat exchange efficiency. At the same time, the detachable water cooling structure facilitates later maintenance and descaling, effectively avoiding cooling attenuation caused by channel blockage. Thus, while maintaining the compact size of the whole machine, it significantly improves the heat dissipation capacity of the high-temperature area of ​​the welding torch, solving the technical problems of narrow cooling channels and poor cooling effect in traditional welding torches.

[0020] 2. This design optimizes the cooling water flow path by adopting a segmented, interconnected structure for both the negative and positive electrode cooling water circuits. This expands the contact area between the cooling medium and high-temperature components, further increasing the effective flow gap in the cooling channels and improving cooling efficiency. This addresses the technical problems of narrow cooling channels and mediocre cooling effects in existing welding torches. The segmented water circuit layout ensures a regular water flow direction and uniform water pressure distribution, reducing dead zones and preventing localized high-temperature heat accumulation. Simultaneously, it provides targeted cooling for critical cathode and anode components, ensuring comprehensive cooling without dead zones. The rationally designed cooling water circuit structure of this design provides comprehensive cooling coverage, effectively extending the service life of the welding torch's core components and overcoming the shortcomings of existing torches with limited lifespan, thus meeting the demands of high-load, long-term continuous welding.

[0021] 3. This design utilizes a coaxial limiting fit structure formed by the annular positioning boss of the centering device and the nozzle to construct a two-stage coaxial limiting fit structure between the nozzle annular positioning boss and the centering device, and between the centering device and the tungsten needle. This provides a stable reference point for the tungsten needle to be completely coaxial with the nozzle channel. With a fixed exposed length of the tungsten needle extending from the centering device, the aforementioned coaxial limiting fit structure extends the lowest point of the tungsten needle closer to the nozzle outlet, significantly shortening the axial distance between the tungsten needle tip and the coaxial limiting reference. Under the conditions of high welding temperatures and equipment vibration, the closer the tip of the slender, rod-shaped tungsten needle is to the coaxial limiting reference, the smaller the amplification effect of radial bending deformation and sway offset at the nozzle outlet. This results in better concentricity between the tungsten needle and the nozzle channel, significantly improving the centering effect. The tungsten needle tip is contained within the channel and not exposed, preventing impact, oxidation, and burn-off, thus extending the tungsten needle's service life. Furthermore, the placement of the tungsten needle closer to the nozzle outlet further shortens the arc ignition distance, ensuring a continuous and stable welding arc and improving weld quality. The tungsten needle coaxial limiting arrangement structure in this case is reasonably designed, with high centering accuracy and good protection, and is suitable for various precision welding scenarios. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the plasma arc welding gun in this embodiment.

[0023] Figure 2 This is a schematic diagram of the structure of the plasma arc welding torch in the embodiment, with the protective sleeve, torch handle, and all piping components concealed.

[0024] Figure 3 yes Figure 2 A schematic diagram of the cross-sectional structure of AA.

[0025] Figure 4 This is one of the cross-sectional schematic diagrams of the plasma arc welding torch in this embodiment, where the torch handle and water connector are concealed.

[0026] Figure 5 This is the second cross-sectional view of the plasma arc welding torch in this embodiment, where the torch handle and water connector are concealed.

[0027] Figure 6 This is a schematic diagram of the plasma arc welding torch in this embodiment, showing the concealed handle and protective sleeve.

[0028] Figure 7 yes Figure 6 Enlarged diagram of point B.

[0029] Figure 8 This is a schematic diagram of the tungsten needle limiting assembly in the disassembled state of the embodiment.

[0030] Figure 9 This is a schematic diagram of the gun head assembly in an embodiment, concealing the adapter sleeve and the copper sleeve.

[0031] Figure 10 This is a schematic diagram of the nozzle structure in an embodiment. Detailed Implementation

[0032] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0034] like Figures 1 to 10As shown in the figure, this embodiment of the invention discloses a plasma arc welding torch, which is mainly composed of a torch body assembly 100 and a torch head assembly 1 that can be detachably combined. The torch head assembly 1 is mounted on the torch body assembly 100 and can be disassembled and maintained separately without disassembling the entire torch. The tungsten needle 2 is coaxially arranged along the central axis of the torch head assembly 1, and the centering device 3 is coaxially sleeved on the outer side of the lower end of the tungsten needle 2 to achieve radial limiting of the lower end of the tungsten needle 2. The nozzle 4 is detachably connected to the bottom of the torch head assembly 1, and the center of the nested groove 41 inside the nozzle 41 is provided with an upwardly protruding annular positioning boss 42. The lower end of the centering device 3 is embedded in the channel of the annular positioning boss 42 to further ensure the centering accuracy of the tungsten needle 2. The tungsten needle limiting assembly 5 is fitted on the outside of the tungsten needle 2 to achieve a stable fixation of the tungsten needle 2; the cooling water circuit assembly consists of a lower water guide sleeve 61, an outer water guide sleeve 62, and a water seal head 63. The lower water guide sleeve 61 is coaxially fitted on the outside of the centering device 3, and its lower part extends into the nested groove 41 of the nozzle 4. The outer water guide sleeve 62 is coaxially fitted on the outside of the nozzle 4 and the water seal head 63. The first annular protrusion 621 on its inner sidewall enables the detachable installation and positioning of the water seal head 63. In specific installation, the water seal head 63 is inserted into the internal channel of the outer water guide sleeve 62 to achieve installation, and the first annular protrusion 621 formed on the inner wall of the outer water guide sleeve 62 serves as a limiting support to hold the bottom of the water seal head 63 to achieve positioning. The first inlet 101 and the second inlet 102 on the gun head assembly 1 are respectively supplied with negative electrode cooling water and positive electrode cooling water. The water seal head 63, the tungsten needle limiting assembly 5 and the inner wall of the gun body assembly 100 enclose each other to form a negative electrode cooling water channel 64. The water seal head 63, the nozzle 4, the lower water guide sleeve 61 and the outer water guide sleeve 62 enclose each other to form a positive electrode cooling water channel 65. The two water channels are independent of each other to ensure smooth flow of the cooling medium. Specifically, the tungsten needle, as the cathode component of the welding gun, is located at the central axis of the welding gun. The upper end is held by the tungsten needle clamp, and the lower tip extends into the channel of the nozzle annular positioning boss 42. The nozzle 4, as the anode component, compresses the plasma arc in the central channel. Specifically, since the annular positioning boss 42 is formed in the nested groove 41, the nested groove 41 is an annular groove structure. A gun handle 300 is also installed on the gun body assembly 100.

[0035] As described above, this design utilizes the detachable design of the gun body assembly 100 and the gun head assembly 1, allowing for separate disassembly and maintenance of the gun head assembly 1 without disassembling the entire gun, thus making it more convenient to use. Simultaneously, the detachable mounting structure of the water seal head 63 and the outer water guide sleeve 62, as well as the detachable mounting structure of the nested groove 41 between the lower water guide sleeve 61 and the nozzle 4, enables flexible disassembly of each component. This facilitates direct removal for cleaning the inner wall of the cooling channel, removing scale and impurities, and ensuring effective cooling. Furthermore, addressing the issue of narrow cooling channels in existing technologies, this invention, without increasing the overall dimensions of the gun body and ensuring a compact structure, achieves axial limiting and embedding of the water seal head through a first annular protrusion on the inner side of the outer water guide sleeve. Without altering the outer diameter of the outer water guide sleeve, a uniform and controllable annular water passage (subsequently the second cooling water channel) is pre-reserved between the outer wall of the water seal head 63 and the inner wall of the outer water guide sleeve 62. This annular water passage is larger than the passively formed assembly gap in existing technologies, resulting in better cooling performance. Moreover, the lower end of the lower water guide sleeve extends into the nested groove inside the nozzle, forming a continuous annular passage between the outer wall of the lower water guide sleeve and the inner wall of the nozzle nested groove, while ensuring the radial limiting strength of the centering device and without increasing the outer diameter of the nozzle. The water cavity (the third cooling water channel described later) also features an increased annular water passage gap compared to the passively formed assembly gap in existing technologies, further enhancing the cooling effect. Through the above-mentioned arrangement, utilizing the cavity structure design with nested grooves inside the nozzle, combined with the detachable water circuit components, the water cooling channel morphology is optimized within a limited radial space, reducing dead water areas, increasing the effective water flow cross-sectional area, and improving the cooling water circulation throughput and heat exchange efficiency. At the same time, the detachable water cooling structure facilitates later maintenance and descaling, effectively avoiding cooling attenuation caused by channel blockage. Thus, while maintaining the compact size of the entire machine, it significantly improves the heat dissipation capacity of the high-temperature area of ​​the welding torch, solving the technical problems of narrow cooling channels and poor cooling effect in traditional welding torches.

[0036] like Figures 3 to 5As shown, in a preferred embodiment, the negative electrode cooling water path 64 adopts a segmented design, divided into a first annular cooling water channel 641 and a first cooling water channel 642. The first annular cooling water channel 641 is formed between the top of the water seal head 63, the outside of the tungsten needle limiting component 5 (specifically the outer wall of the tungsten needle sleeve 53), and the inside of the gun body assembly 100 (specifically the inner wall of the ion gas body 11). It is directly connected to the first water inlet 101. After the negative electrode cooling water enters through the first water inlet 101, it first flows into the first annular cooling water channel 641, and then flows downward to the first cooling water channel 642 between the inner wall of the water seal head 63 and the outside of the tungsten needle limiting component 5 (specifically the outer wall of the tungsten needle sleeve 53). It completely surrounds the outside of the tungsten needle limiting component 5 to achieve cathode component cooling. The positive electrode cooling water path 65 is divided into a second annular cooling water channel 651, a second cooling water channel 652, and a third cooling water channel 653. The second annular cooling water channel 651 is formed between the top of the outer water guide sleeve 62, the outside of the water seal head 63, and the inside of the gun body assembly 100 (specifically, the inner wall of the protective gas body 13), and is connected to the second water inlet 102. The second cooling water channel 652 is formed between the outer wall of the water seal head 63 and the inner wall of the outer water guide sleeve 62, and is connected to the second annular cooling water channel 651. After the positive electrode cooling water is introduced through the second water inlet 102, it first flows through the second annular cooling water channel 651, then flows downward to the second cooling water channel 652, and then continues to flow downward to the third cooling water channel 653 between the inner wall of the nested groove 41 and the outer wall of the lower water guide sleeve 61 of the nozzle 4, forming a circulating cooling loop around the inner and outer walls of the nozzle 4, thereby achieving comprehensive cooling of the nozzle 4.

[0037] As described above, this invention designs the negative electrode cooling water path 64 as a two-section connected structure of the first annular cooling water channel 641 and the first cooling water channel 642, and the positive electrode cooling water path 65 as a three-section connected structure of the second annular cooling water channel 651, the second cooling water channel 652 and the third cooling water channel 653. This achieves a segmented connected structure, optimizes the cooling water flow path, and adapts to the assembly layout of the ion gas body 11, the protective gas body 13 and the tungsten needle clamp sleeve 53. Without increasing the overall size of the torch body and ensuring a compact structure, the cooling water flow path is optimized, the effective water flow cross-sectional area is maximized, the contact area between the cooling medium and the cathode tungsten needle limiting component and the high-temperature component of the anode nozzle is further expanded, the effective flow gap of the cooling channel is further increased, and the cooling efficiency is improved. This solves the technical problems of narrow cooling channels and mediocre cooling effect in existing welding torches. The segmented water circuit layout ensures a regular water flow and uniform water pressure distribution, with no local narrowing structures, significantly reducing dead water zones and preventing localized high-temperature heat accumulation. It also provides targeted, all-around cooling for the cathode conductive components and the high-temperature area of ​​the anode nozzle, ensuring comprehensive cooling without dead zones. The independently zoned dual water circuit design prevents cross-flow and ensures stable cooling circuit pressure. Combined with detachable water circuit components, it facilitates future maintenance and descaling, effectively preventing cooling attenuation caused by flow channel blockage, extending the service life of the welding torch's core components, and overcoming the shortcomings of existing torches with limited lifespan. It perfectly adapts to the demands of high-load, long-term continuous welding.

[0038] like Figure 6 and Figure 7As shown, in a preferred embodiment, the nozzle 4 is detachably connected to the outer water guide sleeve 62 via an external thread; the lowermost end face of the nozzle 4 has a positioning hole 43 for inserting external tools. External tools can be directly inserted into the positioning hole 43 from the lower end of the welding gun to tighten or loosen the nozzle 4, allowing for assembly and disassembly without disassembling external components. Specifically, the upper outer wall of the nozzle 4 is machined with an external thread, and the lower inner wall of the outer water guide sleeve 62 is machined with an internal thread that matches the external thread. The nozzle 4 and the outer water guide sleeve 62 are detachably connected by thread engagement, resulting in a secure assembly and good sealing effect. At least two positioning holes 43 are symmetrically provided on the lowermost end face of the nozzle 4. The positioning holes 43 are recessed inward, allowing for quick assembly and disassembly of the nozzle 4 by simply inserting a simple wrench or insert rod into the positioning hole 43 without disassembling the protective sleeve, air circuit components, or other components outside the gun body, thus eliminating the need to disassemble them. Thus, this design achieves a detachable nozzle structure by threadedly connecting the nozzle 4 to the outer water guide sleeve 62, along with the positioning hole 43 on the lower end face of the nozzle 4. Disassembly can be completed simply by inserting a wrench into the positioning hole, eliminating the need to remove the outer protective sleeve and other components. This solves the technical problems of existing nozzles, such as the inability to directly replace them, cumbersome maintenance, and low maintenance efficiency. The threaded connection ensures a secure assembly of the nozzle 4 and eliminates any jamming during disassembly. The positioning hole 43 design makes the assembly and disassembly operations simple and efficient, significantly reducing nozzle 4 replacement time and improving maintenance efficiency. The nozzle assembly and disassembly structure of this design is simple, highly practical, and effectively improves the ease of maintenance for welding torches.

[0039] like Figure 3 and Figure 8 As shown, in a preferred embodiment, the tungsten needle limiting assembly (5) includes, from the inside out: a tungsten needle clamp (51), a tungsten needle clamp spring (52), and a tungsten needle clamp sleeve (53). The tungsten needle clamp 51 is coaxially sleeved on the upper half of the outer side of the tungsten needle 2, and its lower end forms an elastic clamping head 510. The tungsten needle clamp spring 52 is coaxially sleeved on the outer periphery of the elastic clamping head 510. Utilizing the elastic contraction force of the spring itself, it continuously clamps the elastic clamping head 510 inward, achieving gapless clamping and fixing of the tungsten needle 2. The tungsten needle clamp 51 is integrally limited and embedded inside the tungsten needle clamp sleeve 53. The radial deformation of the tungsten needle clamp 51 is constrained by the inner wall of the tungsten needle clamp sleeve 53, ensuring the stable clamping position of the tungsten needle 2 and preventing displacement during welding. Specifically, the tungsten needle clamp is a clamping and fixing component for the tungsten needle, and the material can be a highly conductive / conductive elastic copper alloy. The inner hole of the tungsten needle clamp holds the upper half of the tungsten needle tightly, the outer wall matches the tungsten needle clamp sleeve, and the upper end abuts against the copper core of the gun tail axially; the elastic clamp head is specifically formed by multiple elastic arms.

[0040] As described above, this invention utilizes the cooperation of the tungsten needle clamp 51, the tungsten needle clamp spring 52, and the tungsten needle clamp sleeve 53 to construct an elastic pre-tightened tungsten needle limiting structure. The tungsten needle 2 is fixed and limited by the pre-tightening force of the tungsten needle clamp spring 52. On the one hand, this ensures the stability of the clamped position of the tungsten needle 2; on the other hand, it lays the structural foundation for the subsequent synchronous disassembly of the tungsten needle and the gun cap, solving the technical problem of needing to clamp the tungsten needle out during the disassembly of the existing tungsten needle and gun cap. The design of the elastic clamp and the spring combination provides a uniform and stable clamping force, which can firmly fix the tungsten needle 2, avoiding the tungsten needle from shifting or deviating due to welding vibration. It also has a certain tolerance compensation capability and an adaptive coaxial compensation capability, which can adaptively adjust the clamping force for slight radial sway caused by the working conditions of the tungsten needle, correct the coaxiality in real time, and always keep the tungsten needle accurately aligned. It can also be adapted to the assembly of tungsten needles of slightly larger or smaller specifications, making it highly versatile. The outer limit protection of the tungsten needle clamp sleeve 53 prevents the tungsten needle clamp 51 from deforming under force, and the clamping accuracy does not decrease with long-term use, further improving the centering effect of the tungsten needle, solving the defect of the average centering effect of existing tungsten needles, and ensuring welding stability.

[0041] like Figure 3 and Figure 8 As shown, in a preferred embodiment, an isolation ring 54 is added between the top of the lower water guide sleeve 61 and the bottom of the tungsten needle clamp sleeve 53. The isolation ring 54 is an insulating isolation component made of insulating material, coaxially sleeved on the outer side of the lower end of the tungsten needle clamp sleeve 53, with its upper and lower end faces abutting against the bottom of the tungsten needle clamp sleeve 53 and the top of the lower water guide sleeve 61, respectively. This achieves axial isolation and electrical disconnection between the lower water channel assembly (lower water guide sleeve 61, water seal head 63, etc.) and the upper tungsten needle limiting assembly (tungsten needle clamp 51, tungsten needle clamp sleeve 53, etc.), while sealing the assembly gap between the two. Specifically, the lower end of the tungsten needle clamp sleeve has a stepped protrusion, and the stepped protrusion of the tungsten needle clamp sleeve extends into the isolation ring. The top of the centering device also extends into the isolation ring, restricting the axial movement of the tungsten needle clamp. Thus, this design achieves axial isolation and electrical disconnection between the upper and lower components by adding an insulating isolation ring 54 between the lower water guide sleeve 61 and the tungsten needle clamp sleeve 53, preventing creepage and leakage, reducing hard contact wear of components, and extending the service life of the welding torch. The isolation ring 54, in conjunction with the positioning step at the lower end of the tungsten needle clamp sleeve 53 and the nested fit at the top of the centering device 3, can constrain radial offset, limit axial movement of the tungsten needle clamp 51, improve the concentricity of the tungsten needle 2 and the nozzle 4, and simultaneously seal assembly gaps, prevent the entry of water vapor and impurities, ensure the stability of the cooling water circuit, and improve the structural stability and safety of the welding torch.

[0042] like Figure 3 and Figure 9As shown, in a preferred embodiment, the gun head assembly 1 further includes a gun tail assembly 7 disposed at the top of the gun body assembly 100. The gun tail assembly 7 includes a gun cap 71, a retaining ring 72, a gun tail copper core 73, and a gun tail copper sleeve 74. The gun tail copper core 73 is coaxially disposed at the inner center of the gun tail copper sleeve 74, and its lower end is fitted and connected to the top of the tungsten needle clamp 51 to conduct welding current to the tungsten needle 2, thereby achieving stable conduction of welding current to the tungsten needle 2. The top part of the gun tail copper core 73 is exposed outside the gun tail copper sleeve 74. The retaining ring 72 is coaxially clamped on the outer periphery of the top part of the gun tail copper core 73 and axially abuts against the top wall of the gun tail copper sleeve 74 to achieve axial locking of the gun tail component and prevent loosening. The gun cap 71 is coaxially fastened to the outer periphery of the gun tail copper sleeve 74, covering and protecting the gun tail assembly 7 as a whole. When the gun cap 71 is removed, the gun tail copper core 73, the tungsten needle clamp 51, and the tungsten needle 2 can be removed simultaneously without the need to clamp the tungsten needle 2 separately. Thus, this invention utilizes a tail assembly to connect the gun cap 71, the tail copper core 73, and the tungsten needle clamp 51. When disassembling the gun cap 71, the tungsten needle 2 can be simultaneously removed without needing to be clamped separately, significantly simplifying the tungsten needle assembly and disassembly process and solving the technical problems of cumbersome disassembly and disassembly of existing tungsten needles and gun caps, which require separate clamping of the tungsten needle. The tail copper core directly connects to the tungsten needle clamp, resulting in a short conductive path and stable current transmission, preventing arc interruption during welding. The retaining ring is fitted onto the exposed section of the tail copper core and abuts against the top wall of the tail copper sleeve, providing more reliable axial locking and effectively preventing loosening and shaking of the tail components, improving structural stability and extending the service life of the gun body. The tail assembly in this invention has a simple structure, is easy to assemble, and balances assembly / disassembly efficiency with welding stability.

[0043] like Figure 3 and Figure 10 As shown, in a preferred embodiment, the annular positioning boss 42 of the nozzle 4 has a through-hole 420 at its center. The through-hole 420 is coaxially arranged with the tungsten needle 2. After the tip of the tungsten needle 2 passes through the central through-hole of the centering device 3, it precisely exits into the through-hole 420 of the nozzle 4, and the tip of the tungsten needle 2 is contained in the through-hole 420 and does not extend beyond the lower end face of the nozzle 4. The annular positioning boss 42 is used to limit the centering device 3. Specifically, the lower end of the centering device 3 is embedded in the annular positioning boss 42. The centering device 3 is radially limited by the inner wall of the annular positioning boss 42, and the tungsten needle 2 is radially limited by the central through-hole of the centering device 3. In specific implementation, the exposed section length of the tungsten needle 2 extending from the lower end of the center hole of the centering device remains unchanged. Under the premise of fixed exposed section length, the centering device 3 is embedded into the nozzle 4 through the above-mentioned structural design, so that the centering device is closer to the nozzle outlet. In this way, when the lowest end of the tungsten needle 2 is extended to the lower end face of the welding end outlet of the nozzle 4, the lowest end of the tungsten needle 2 can also be closer to the nozzle outlet.

[0044] As described above, this invention constructs a two-stage coaxial limiting fit structure between the nozzle annular positioning boss 42 and the centering device 3, and between the centering device and the tungsten needle, through the coaxial limiting fit structure formed by the centering device 3 and the annular positioning boss 42 of the nozzle 4. This provides a stable reference for the tungsten needle 2 to be completely coaxial with the nozzle 4 channel. Under the premise that the exposed length of the tungsten needle 2 passing through the centering device 3 remains constant, the lowest end of the tungsten needle 2 can be extended to a position closer to the nozzle outlet through the above-mentioned coaxial limiting fit structure. This can significantly shorten the axial distance between the tip of the tungsten needle and the coaxial limiting reference. Under the conditions of high welding temperature and equipment vibration, the closer the tip of the slender rod-shaped tungsten needle is to the coaxial limiting reference, the smaller the amplification effect of radial bending deformation and sway offset at the nozzle outlet. The concentricity between the tungsten needle 2 and the nozzle 4 channel is better, which significantly improves the centering effect. The tip of the tungsten needle 2 is concealed within the channel 420 and not exposed, preventing damage from impacts and oxidation, thus extending its service life. Furthermore, the placement of the tungsten needle closer to the nozzle outlet further shortens the arc ignition distance, ensuring a continuous and stable welding arc and improving weld quality. The coaxial positioning structure of the tungsten needles in this design is rationally designed, offering high centering accuracy and excellent protection, making it suitable for various precision welding scenarios.

[0045] like Figures 4-6 As shown, in a preferred embodiment, the gun assembly 100 of this case is composed of an ion gas body 11, an insulating pad 12, a protective gas body 13, and a protective sleeve 14. The ion gas body 11 is located at the top and coaxially sleeved on the outside of the tungsten needle limiting assembly 5. Its first air inlet 111 is used to introduce ion gas, and its first water inlet 101 is used to introduce negative electrode cooling water. The protective gas body 13 is located at the bottom and coaxially sleeved on the outside of the outer water guide sleeve 62. Its second air inlet 131 is used to introduce protective gas, and its second water inlet 102 is used to introduce positive electrode cooling water. An insulating pad 12 is sandwiched between the ion gas body 11 and the protective gas body 13 to achieve electrical isolation between the two. The protective sleeve 14 is divided into an upper enclosure structure 141 and a lower enclosure structure 142, which completely enclose the ion gas body 11, the insulating pad 12, and the protective gas body 13. An independent pipeline is reserved inside to connect to each air inlet and water inlet, and a sealing ring 200 is embedded in each docking end face to achieve sealing and leak prevention of the gas and water circuits. Specifically, the independent pipelines include: an ion gas pipe 201 connected to the first air inlet 111, a negative electrode water inlet pipe 202 connected to the first water inlet 101, a protective gas pipe 203 connected to the second air inlet 131, and a positive electrode water inlet pipe 204 connected to the second water inlet 102; the negative electrode water inlet pipe 202 and the positive electrode water inlet pipe 204 are respectively connected to a negative electrode water connector 205 and a positive electrode water connector 206 at their top ends. The ion gas body 11, the insulating pad 12, and the protective gas body 13 are all hollow structures.

[0046] As described above, this invention utilizes a modular design for the gun assembly 100, assembling the ion gas body 11, protective gas body 13, and protective sleeve 14 in layers. This allows for flexible disassembly of the gun components, enabling maintenance by removing only the damaged parts without replacing the entire gun, effectively extending its service life and addressing the technical issue of limited service life in existing guns. The insulating pad 12 provides electrical isolation between the upper and lower components, preventing cross-current and leakage, and improving safety. The integrated design of the protective sleeve 14 effectively provides waterproofing, dustproofing, and impact protection. Its internal independent piping layout is well-organized, and combined with the sealing ring 200, it achieves a complete seal, preventing gas and water leaks, ensuring smooth cooling water flow, and improving cooling efficiency, thus overcoming the shortcomings of narrow cooling channels and mediocre cooling effects. This invention features a compact gun structure, convenient assembly, good protection, and suitability for various industrial welding conditions.

[0047] like Figures 3-6 As shown, in a preferred embodiment, the outer water guide sleeve 62 is coaxially fitted with a side diffuser 81 and a uniform diffuser 82 from top to bottom on its outer side. A transition sleeve 83 is coaxially fitted on the outside of the side diffuser 81. The outer wall of the transition sleeve 83 is machined with external threads, and the inner wall of the upper end of the copper sleeve 84 is machined with matching internal threads. The transition sleeve 83 and the copper sleeve 84 are fixed by threaded connection. The copper sleeve 84 is completely covered on the outside of the nozzle 4, which plays a protective role. The transition sleeve 83 serves as an intermediate connecting part, realizing the modular disassembly and assembly of the lower protective components (uniform diffuser 82, side diffuser 81, and copper sleeve 84).

[0048] As described above, this design achieves a modular and detachable lower protective component through the threaded connection of the adapter sleeve 83 and the copper sleeve 84. This design is compatible with the overall detachable structure of the welding torch, allowing for individual removal and replacement of the lower protective component during maintenance without disassembling the entire torch. This further improves maintenance efficiency, reduces component wear, extends the torch's service life, and addresses the technical issue of the limited service life of existing torches. The cooperation between the diffuser 82 and the side diffuser 81 can divert and rectify the shielding gas, preventing turbulent airflow and ensuring welding quality. The copper sleeve 84 covers the outside of the nozzle 4, resisting spatter and impact, reducing external mechanical damage to the nozzle 4, lowering the replacement frequency of the nozzle 4, indirectly improving maintenance efficiency, while not affecting the quick installation and removal of the nozzle 4 or interfering with the normal flow of cooling water. The lower protective structure design of this design is reasonable and highly practical, further optimizing the overall performance of the welding torch.

[0049] like Figure 3 and Figure 9As shown, in a preferred embodiment, this invention also installs sealing rings 200 of corresponding specifications at all the inner and outer nested connection gaps of the nozzle 4 and the lower water guide sleeve 61, the nozzle 4 and the outer water guide sleeve 62, the lower water guide sleeve 61 and the water seal head 63, the water seal head 63 and the tungsten needle limiting component 5, and the outer water guide sleeve 62 and the gun body assembly 100, so as to achieve sealing at each connection point; and installs flat rubber gaskets 9 at the plane position where the gun body assembly 100 and the water seal head 63 meet vertically to achieve end face sealing between the two. Through the full-area sealing layout, water circuit sealing, air circuit sealing and cavity isolation sealing are achieved respectively to prevent cooling water leakage, air circuit leakage and medium crossflow between cavities.

[0050] As described above, this design employs a comprehensive, multi-point sealing system, embedding sealing rings 200 at the joints of various components. Combined with the flat rubber gasket 9 between the gun body assembly 100 and the water seal head 63, this completely eliminates water leakage and cross-contamination in the cooling water circuit, ensuring stable cooling circuit pressure, smooth flow of the cooling medium, and further improving cooling performance. The sealing components also isolate the air and water circuits, preventing moisture from entering the air circuit cavity and avoiding moisture affecting welding quality. The flat rubber gasket 9 buffers the hard compression of the end face, providing both sealing and shock absorption, reducing component wear, extending component lifespan, and addressing the shortcomings of existing gun bodies with limited lifespan. This comprehensive sealing structure design ensures reliable sealing performance, effectively improving the stability and durability of the welding gun, and making it suitable for long-term continuous welding operations.

[0051] In summary, this invention discloses a plasma arc welding torch, aiming to solve the technical problems of poor cooling effect, cumbersome nozzle disassembly and maintenance, low tungsten needle centering accuracy, and short torch lifespan in existing welding torches. It includes a torch body assembly and a torch head assembly detachably mounted on the torch body assembly. The torch head assembly contains a tungsten needle, a centering device, a nozzle, a tungsten needle limiting component, and a cooling water circuit assembly. The cooling water circuit assembly constructs independent negative and positive dual cooling water circuits, employing a segmented surrounding flow channel design. The nozzle has an annular positioning boss, forming a two-stage coaxial limiting system with the centering device. The torch body assembly integrates an independent dual gas circuit structure for ion gas and shielding gas, and the torch tail adopts an integrated quick-release structure. This invention significantly improves the cooling efficiency of the welding torch and the centering accuracy of the tungsten needle while maintaining a compact structure, enabling rapid disassembly and maintenance of vulnerable parts, effectively extending the service life of the welding torch, and is widely adaptable to various high-load continuous welding industrial scenarios.

[0052] As stated above, this case protects a plasma arc welding torch, and all technical solutions that are the same as or similar to this case should be considered to fall within the scope of protection of this case.

Claims

1. A plasma arc welding torch, characterized in that, include: The gun body assembly (100) and the gun head assembly (1) mounted on the gun body assembly (100) include: a tungsten needle (2), a centering device (3), a nozzle (4), a tungsten needle limiting assembly (5), and a cooling water circuit assembly; the tungsten needle (2) is coaxially disposed at the central axis inside the gun head assembly (1), and the centering device (3) is coaxially sleeved on the outer side of the lower end of the tungsten needle (2); the nozzle (4) is detachably connected to the bottom of the gun head assembly (1), and a nesting groove (41) is provided inside the nozzle (4), and an upwardly protruding annular positioning boss (42) is coaxially provided at the center of the nesting groove (41); the lower end of the centering device (3) is embedded in the annular positioning boss (42); the tungsten needle limiting assembly (5) is sleeved on the outer side of the tungsten needle (2) for fixing the tungsten needle (2); the cooling water circuit assembly includes a lower water guide sleeve (61) and an outer water guide sleeve. (62) and water seal head (63), the lower water guide sleeve (61) is coaxially sleeved on the outside of the centering device (3), and the lower part of the lower water guide sleeve (61) extends into the nested groove (41) of the nozzle (4); the outer water guide sleeve (62) is coaxially sleeved on the outside of the nozzle (4) and the water seal head (63), and the water seal head (63) is embedded in the inside of the outer water guide sleeve (62); the nozzle assembly (1) is provided with a first for negative electrode cooling water to enter. A water inlet (101) and a second water inlet (102) for positive electrode cooling water to enter; a negative electrode cooling water passage (64) is formed between the water seal head (63), the outside of the tungsten needle limiting assembly (5) and the inner wall of the gun body assembly (100) and communicates with the first water inlet (101); a positive electrode cooling water passage (65) is formed between the water seal head (63), the nozzle (4) and the outer water guide jacket (62) and communicates with the second water inlet (102).

2. The plasma arc welding torch according to claim 1, characterized in that, The negative electrode cooling water path (64) includes a first annular cooling water channel (641) that communicates with the first inlet (101) and is formed between the top of the water seal head (63), the outside of the tungsten needle limiting assembly (5), and the inside of the gun body assembly (100), and a first cooling water channel (642) that communicates with the first annular cooling water channel (641) and is disposed between the inner wall of the water seal head (63) and the outside of the tungsten needle limiting assembly (5); the positive electrode cooling water path (65) includes: an enclosed... A second annular cooling water channel (651) is formed between the top of the outer water jacket (62), the outside of the water seal head (63), and the inside of the gun body assembly (100) and is connected to the second water inlet (102). A second cooling water channel (652) is formed between the outer wall of the water seal head (63) and the inner wall of the outer water jacket (62). A third cooling water channel (653) is connected to the second cooling water channel (652) and is formed between the inner wall of the nested groove (41) and the outer wall of the lower water jacket (61).

3. The plasma arc welding torch according to claim 1, characterized in that, The nozzle (4) is detachably connected to the inner thread of the outer water guide sleeve (62) via an external thread; the lowermost end face of the nozzle (4) is provided with a positioning hole (43) for inserting external tools.

4. The plasma arc welding torch according to claim 1, characterized in that, The tungsten needle limiting assembly (5) includes, from the inside out: a tungsten needle clamp (51), a tungsten needle clamp spring (52), and a tungsten needle clamp sleeve (53); the tungsten needle clamp (51) is coaxially sleeved on the upper half of the outer side of the tungsten needle (2), and the tungsten needle clamp (51) has an elastic clamp head (510) at its lower end. The tungsten needle clamp spring (52) is coaxially sleeved on the outer side of the elastic clamp head (510) to provide pre-tightening force; the tungsten needle clamp (51) is limited and embedded inside the tungsten needle clamp sleeve (53).

5. A plasma arc welding torch according to claim 4, characterized in that, An isolation ring (54) is provided between the top of the lower water guide sleeve (61) and the bottom of the tungsten needle clamp sleeve (53). The isolation ring (54) is coaxially sleeved on the outer side of the lower end of the tungsten needle clamp sleeve (53) and abuts against the lower water guide sleeve (61).

6. A plasma arc welding torch according to claim 4, characterized in that, The gun head assembly (1) also includes a gun tail assembly (7) disposed at the top of the gun body assembly (100). The gun tail assembly (7) includes a gun cap (71), a retaining ring (72), a gun tail copper core (73), and a gun tail copper sleeve (74). The gun tail copper core (73) is coaxially disposed at the inner center of the gun tail copper sleeve (74), and its lower end is sleeved and connected to the top of the tungsten needle clip (51). The gun tail copper sleeve (74) is coaxially disposed on the outside of the gun tail copper core (73). The gun cap (71) is coaxially fastened to the outside of the gun tail copper sleeve (74). The retaining ring (72) is coaxially snapped onto the outer periphery of the top of the gun tail copper core (73) and abuts against the top wall of the gun tail copper sleeve (74).

7. The plasma arc welding torch according to claim 1, characterized in that, The nozzle (4) has an annular positioning boss (42) with a channel (420) in the middle. The tip of the tungsten needle (2) passes through the centering device (3) and extends into the channel (420) of the nozzle (4) without extending out of the nozzle (4).

8. A plasma arc welding torch according to claim 1, characterized in that, The gun head assembly (1) includes: an ion gas body (11), an insulating pad (12), a protective gas body (13), and a protective sleeve (14); the ion gas body (11) is coaxially sleeved on the outside of the tungsten needle limiting assembly (5), and is provided with a first air inlet (111) for ion gas to enter and a first water inlet (101); the protective gas body (13) is coaxially sleeved on the outside of the outer water guide sleeve (62), and is provided with a second air inlet (131) for protective gas to enter and a second water inlet (102); the insulating pad (12) The protective sleeve (14) is connected between the ion gas body (11) and the protective gas body (13). The protective sleeve (14) is used to surround the ion gas body (11), the insulating pad (12), and the protective gas body (13), and is provided with pipelines that are respectively connected to the first air inlet (111), the first water inlet (101), the second air inlet (131), and the second water inlet (102). One or more sealing rings (200) are embedded between the ion gas body (11) and the insulating pad (12), and between the insulating pad (12) and the protective gas body (13).

9. A plasma arc welding torch according to claim 1, characterized in that, The outer water guide sleeve (62) is coaxially fitted with a side diffuser (81) and a uniform diffuser (82) distributed vertically; the side diffuser (81) is coaxially fitted with a transition sleeve (83), and the transition sleeve (83) is connected to a copper sleeve (84) by a threaded connection. The copper sleeve (84) is located outside the nozzle (4).

10. A plasma arc welding torch according to claim 1, characterized in that, One or more sealing rings (200) are installed between the nozzle (4) and the lower water guide sleeve (61), between the nozzle (4) and the outer water guide sleeve (62), between the lower water guide sleeve (61) and the water seal head (63), between the water seal head (63) and the tungsten needle limiting assembly (5), and between the outer water guide sleeve (62) and the gun body assembly (100); a flat rubber pad (9) is installed between the upper and lower joints of the gun body assembly (100) and the water seal head (63).

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