An electrode prepared with an increased surface area for cooling that connects a copper electrode body and an emitter cutter tip (insert) for a plasma cutting torch

Abstract

A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the copper electrode having an increased cooling surface area and thus an increased lifespan and efficiency; The emitter cutter tip has a surface-increasing flow passage (3a) with a concave / convex surface on its side and a surface-increasing flow passage (3b) with a concave / convex surface on its top surface, and has a diameter that expands from the outer diameter to the tip in a bowl shape; and 1. A plasma cutting torch copper electrode comprising: a downstream electrode body (2) carrying an emitter cutter tip (3) having a cavity (4) in which the emitter cutter tip (3) is fixed.

Description

[Technical field]

[0001] The present invention relates to a copper-bodied electrode for a plasma cutting torch that connects an emitter (also called an electron source) cutter tip (also called an insert) for a plasma cutting torch and a copper-bodied electrode body, thereby increasing the surface area of ​​the cooling surface and thereby increasing its life and efficiency. [Background technology]

[0002] As with plasma cutting torches with automatic or manual liquid or air cooling systems, arc plasma cutting torches are based on a similar architecture, with an electrode consisting of an emitter cutter tip, a gas diffuser, and a body to which a nozzle for narrowing the plasma jet is fixed.

[0003] Generally, the copper body electrodes used in these plasma torches consist of a copper body with an electron emitting cutter tip or emitter cutter tip fixed in it. The cutter tip is tungsten or hafnium or zirconium. This emitter cutter tip is typically cylindrical in shape and is fixed by stamping, crimping or hard driving into a cavity such as a blind hole (the cavity in which the emitter cutter tip is fixed) located at the downstream end of the electrode body.

[0004] Pressurized cooling water enters the plasma cutting torch through various connections from the center of the cutting torch, connected to a flow path within the torch through a submerged water tube connected to the circulating discharge line of the plasma cutting torch, and is transported by the submerged water tube to near the bottom of the blind hole of the copper electrode, and is returned to the cooling system by a cooling water circulation return pipe that is connected upward between the outer part of the electrode blind hole and the outer diameter of the submerged water tube, where the return flow path in the plasma cutting torch performs cooling and cleaning.

[0005] All liquid-cooled plasma cutting torches in use, past and present, have a similar architecture whose technology is known by the companies that manufacture the copper electrodes.

[0006] It is well known that during the plasma cutting process, the emitter cutter tip (insert) is exposed to suction forces and especially very high temperatures generated more or less by the arc plasma jet, which starts to take root at the emitter cutter tip.

[0007] Inevitably, exposed to the plasma jet, the metal or metal alloy forming the emitter cutter tip is significantly vaporized and therefore abraded resulting in the formation of a crater inside said emitter cutter tip.

[0008] Due to this wear, a more or less rapid deterioration of the tip of the copper electrode of the plasma torch is almost inevitable and represents a real problem on an industrial scale.

[0009] It also affects the efficiency of the cutting process because it requires frequent replacement of the torch electrode, and the replacement of the electrode stops the system, stops the cutting process, and incurs additional costs. If the emitter cutter tip breaks down, it is not possible to replace only the emitter cutter tip, but the entire electrode that must be replaced.

[0010] In the case of additional materials, for example hafnium and copper, whose thermal conductivity coefficient is very low compared to the material forming the copper electrode body, with the highest possible purity value, hafnium having a thermal conductivity close to 5.75% compared to that of copper, it is known that the very high temperatures caused by the initiation of the arc plasma jet and the low thermal conductivity of the material in which the insert is made prevent high heat transfer and better cooling. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to minimize the above mentioned drawbacks and to find a solution to this problem.

[0012] Due to the higher thermal and electrical conductivity of silver compared to copper, electrodes made of silver and / or silver / copper and / or copper-silver alloys have a slightly longer life than electrodes made of copper.

[0013] However, the cost of silver is much higher than the cost of copper, which significantly increases the cost of the electrode. [Means for solving the problem]

[0014] The increased cooling surface area flow passage of the present invention creates an alternative to copper body cutting electrodes with a cutting electrode life that is more than doubled, which reduces the cost of the electrode.

[0015] For this purpose, an increase in the surface area is achieved by the formation of parallel, equally spaced concaves / convexities (also called indentations / protrusions) (also called depressions / protrusions) on the cylindrical outer surface of the emitter cutter, which is fixed to the lower end of the copper electrode body from the electrode tip upwards; The emitter cutter tip exposed to high heat from the extreme point where the cutting process begins is cooled due to the increased heat transfer surface required for the fixed body to cool from the extreme point, so that the emitter cutter tip exposed to high heat is ensured to be well cooled and the amount of evaporation caused by high heat is reduced, so that its working life is extended.

[0016] This results in an increased surface area of ​​equal and equal spaced convexities / concaves, on the bowl and cylindrical outer surface oriented upward from the copper electrode tip of the emitter cutter tip fixed to the lower end of the copper electrode body, of parallel identical profile cross sections, on the cylindrical upper end of the cutter tip oriented upward from said tip, and having a heat transfer surface area increase of 80% or more; and The cylindrical upper end of the cutter tip is formed by an increased surface area from the outer diameter to the center, consisting of parallel, identical profile cross sections, shrinking at equal intervals toward the center, and having a heat transfer surface area increase of 80% or more. The emitter cutter tip, which is exposed to high heat during operation, is better cooled, reducing the amount of mass loss due to evaporation and phase transitions caused by high temperatures, and thus extending its operating life. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1: Cross-sectional view of a plasma cutting torch copper electrode with a liquid cooling system having a surface increase by concave / convex means on the cooling surface connecting the emitter cutter tip to the copper electrode body; [Diagram 2] FIG. 2 is a cross-sectional view of the surface increase by means of concave / convex on the cooling surface connecting the emitter cutter tip to the copper electrode body; [Diagram 3] FIG. 3 is a top cross-sectional view of the surface increase by means of concave / convex on the cooling surface connecting the emitter cutter tip to the copper electrode body; [Figure 4-1] FIG. 4a: Cross-section of an emitter cutter tip whose surface is augmented by means of a concave / convex cooling surface connected to a copper electrode body, with a root abrasion value of 1.9 mm measured from the center of the crater, generated by an arc plasma jet at the emitter cutter tip; [Figure 4-2] Figure 4b: Cross-section of an emitter cutter tip whose surface is augmented by means of a concave / convex cooling surface connected to a copper electrode body, with a root abrasion value of 2.38 mm measured from the centre of the crater formed by the arc plasma jet at the emitter cutter tip. [Explanation of symbols]

[0018] 1: A copper electrode with a liquid cooling system in a plasma torch for cutting metal pieces; 2: A downstream copper electrode body carrying the emitter cutter tip; 3: Emitter cutter tip, 3a: Surface-increasing channel with concave / convex sides 3b: Surface-increasing channel with concave / convex upper surface 3c: The diameter of the bowl-shaped opening that expands from the outer diameter to the tip 4: The cavity where the emitter cutter tip is fixed to the copper electrode body. 5: Underwater coolant piping A: Bowl depth DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention is a copper electrode for a plasma cutting torch that connects an emitter cutter tip for plasma cutting and a copper electrode body, and is characterized in that it has a lifespan and efficiency that are extended with an increase in the surface area of ​​the cooling surface, and is characterized by having an emitter cutter tip having a surface-increasing flow passage (3a) with concave / convex formed on the side, a surface-increasing flow passage (3b) with concave / convex formed on the top surface, a diameter that expands in a bowl shape from the outer diameter to the tip, and a downstream (downstream: along the flow) electrode body (2) that carries the emitter cutter tip (3) having a cavity (also called a cavity) (4) to which the emitter cutter tip (3) is fixed (Figure 1).

[0020] The cavity (4) is drilled upward from the depth (A) of the cavity (4) bowl (3c) to the emitter cutter tip (3) drive area, and the emitter cutter tip is fixed at a relatively low value compared to the cooling channel (3a) thread minor diameter opening on the cylindrical side of the emitter cutter tip (3). emitter cutter tip is secured with a relatively low value compared to the cooling channels (3a) thread minor diameter opened on the cylindrical side surface of the emitter cutter tip (3)).

[0021] The bowl (3c) form, which extends from the upper line of the depth (A) of the bowl (3c) to the tip of the electrode (1), is processed in a small manner in the copper electrode (1) in the cavity (4) in which the emitter cutter tip is fixed, and is slightly different from the shape that follows. from the upper line of the bowl (3c) depth (A) to the tip of the electrode (1), is processed in a small manner in the copper-body electrode (1), in the cavity (4) where the emitter cutter tip is secured, with slight difference from the The form follows.

[0022] Copper-bodied emitter cutter tip (3) The cooling passages (3a) in the bowl-shaped diameter (3c) of the emitter cutter tip are shaped and mounted in a cavity (4) that is fixed during the actuation process under vacuum. in). (Reference English: The cooling channel indentations / protrusions (3a) of the bowl-shaped diameter (3c) of the copper-bodied emitter cutter tip (3) are shaped and mounted in the cavity (4) where they are secured during the driving process under vacuum)

[0023] As seen in Fig. 2, the present invention relates to a plasma cutting torch copper electrode that connects an emitter cutter tip for a plasma cutting torch to a copper electrode body, and extends its life and efficiency with a surface increase of the cooling surface. It has surface increase channels (3a, 3b) formed on its side and top surfaces, which are concave / convex, to ensure more cooling when the emitter cutter tip (3) is exposed to high heat during operation, which is configured with a copper electrode (1) and an arc formed by exposure to the suction force generated by an arc plasma jet of tungsten, hafnium, or zirconium when performing a metal cutting process (Fig. 2, Fig. 3).

[0024] A copper electrode with a liquid cooling system in a plasma torch is created by fixing an emitter cutter tip (3), which has surface-increasing channels (3a, 3b) formed on its side and top surfaces for cooling purposes, into a cavity (4) in a copper electrode body (2) for cutting metal pieces (Figure 1).

[0025] The shapes were made with a 260 amp liquid cooled copper electrode; they were cut in a mild steel sheet of 25 mm thickness and A1 quality according to the system catalogue cutting parameters; the copper electrode was finished with 1184 blasting; and the root abrasion depth created by the arc plasma jet from the electrode tip level on the emitter cutter tip (3) was observed to be 1.9 mm, measured from the crater centre, Fig. (4a). (Reference English: The shapes were made with 260 Ampere liquid-cooled copper-bodied electrode; these shapes were cut with 25-mm thick and A1-quality soft iron sheet cutting according to the catalog cutting parameters of the system; the copper-bodied electrode was removed by 1184 blasts; and the root abrasion depth, which is created by the arc plasma jet on the emitter cutting tip (3) from the level of the electrode tip, was observed to be 1.9 mm when measured from the crater center, fig. 4a.)

[0026] The root abrasion depth formed by the arc plasma jet on the emitter cutter tip (3) from the electrode tip level, with reconnection of the copper-bodied electrode, the continuation of the cutting with the same shapes' system catalog cutting parameters, the performance of 648 more blasts, was calculated as 2.38 mm (Fig. 4b).

[0027] This difference of values ​​(2.38 (-) 1.9) shows that 648 blastings were obtained at 0.48 mm of abrasion.

[0028] In the calculation made according to these values, when the copper-bodied electrode reached a depth of 1.9 mm from the first point of cutting, 2565 blasts would have been obtained if it went with a linear decrease, while 1184 explosions were obtained due to the depth lost due to excessive evaporation at 1.9 mm.

[0029] This indicates that the evaporation rate and mass loss decrease logarithmically as closer to the liquid cooling zone as better cooling is provided.

[0030] In such a situation where cooling is important, a surface increase of about 80% is achieved on the fixed surface due to the surface increasing flow passages (3a, 3b) formed by the concave / convex on the side and top surface of the emitter cutter tip (3) corresponding to the cavity (4) where the emitter cutter tip (3) is fixed to the copper electrode body, and during its fixing to the copper electrode body (2) connected to these concave / convex, from the extremely severe point where the emitter cutter tip (3) starts cutting, and the life of the emitter cutter tip (3) is extended with increased cooling transfer (Figure 1). (Reference English: This situation, in which cooling is of such importance, with a surface increase of around 80% from the surface increase channels (3a, 3b) formed by the indentations / protrusions on the side and upper surfaces of the emitter cutter tip (3), which corresponds to the cavity (4) where the emitter cutter tip (3) is secured to the copper-bodied electrode body and from the extreme point where the emitter cutter tip (3) starts cutting, during its fixation to the copper-bodied electrode body (2), which is connected with these indentations / protrusions, a surface increase of around 80% was achieved on the securing surfaces and the life of the emitter cutter tip (3) was extended with the increase in cooling transmission (Figure-1).

[0031] It was measured that in blasting and cutting with a 260 ampere electrode, with an A1 quality mild steel sheet to a thickness of 25 mm, with an arc plasma jet taking root starting from the initial start level of the cut of the emitter cutter tip (3), a hemispherical or hemispherical crater was formed with 1.9 mm wear (depth) from the crater center, and the rim of the crater was about 1.84 mm in diameter. (Reference English: In the blasting and cutting with crater liquid-cooled system formed by the arc plasma jet starting to take root from the first starting level of the cutting of the emitter cutter tip (3), with a 260 Ampere electrode, to a 25 mm of thickness, with an A1 -quality soft iron sheet, it was measured that a hemisphere or hemispherical crater was formed at 1 .9 mm abrasion measurement from the crater center, and the rim of the crater was around 1.84 mm in diameter.)

[0032] This diameter was measured around 1.9 mm in diameter 0.4 mm above the copper-bodied electrode tip level.

[0033] Between these two diameters, a cone-shaped wear of approximately 1 degree is observed at a depth distance of 1.9 mm to 1.84 mm. (This diameter was measured around 1.9 mm in diameter 0.4 mm above the copper-bodied electrode tip level.)

[0034] In the abrasion of the emitter cutter tip (3), in the section from the tip level of 0.4 mm after the depth to the tip level of the copper-bodied electrode, a 1.9 mm diameter expanded towards the outside in the form of a bowl (Fig. 5a)

[0035] This wearing effect of the copper electrode body (2), which is the furthest from cooling, occurs after a certain amount of work in all cutting electrodes with different diameters depending on the amperage.

[0036] For this reason, a profile has been created by adding the diameter of the bowl tip level that the emitter cutter tip (3) can be opened according to the amperage and the indentation depth tolerance to the emitter cutter tip (3) at the depth of the bowl (Fig. 4a, Fig. 4b).

[0037] At the bowl depth (A) level of the emitter cutter tip (3), the setting can be such that it proceeds in a straight or conical shape from the outer diameter of the emitter cutter tip (3) to the top surface of the emitter cutter tip (3) at an angle of about 1 to 2 degrees relative to the center line from bottom to top (Figures 4a and 4b).

[0038] It has an enlarged diameter (3c) proportional to the depth of the equally spaced concave / convex openings in an upward direction from the outer diameter of the emitter cutter tip (3) at the level of the bowl depth (A) to the flat or conical end of the emitter cutter tip (3) (Figures 4a, 4b).

[0039] It can be formed with any number of concavities / convexities, with any suitable geometric cross-section to create the highest surface increase, and with any suitable geometric extensions according to the diameter of the emitter cutter tip (3), calculated according to the maximum cutting amperage.

[0040] The concaves / convexities can be formed on the surface of the emitter cutter tip (3) by a suitable CNC machine having a precision knurling system with suitable knurling rollers and accurate tolerances so that a profile milling cutter made of a suitable hard metal material or a hard metal material on a suitable bench with high precision CNC control can be used, and the concaves / convexities can be formed on the upper surface of the emitter cutter tip (3) using a profile knife (Figures 2, 3).

[0041] Depending on the geometrical section of the channels (3a, 3b) opened by knurling, the number of channels, the depth to which they will be driven, and the amount of sawdust to be scraped and swept during driving, an appropriate headroom is left where the tip is driven into the body of the copper-bodied electrode and secured to the copper electrode body.

[0042] Although there are other methods, the current method of using an emitter cutter tip (3) in a copper electrode body (2) is to drive it in by drawing a vacuum. A line vacuum is the quickest and least costly method.

[0043] The electrode life of the invention is increased in copper-bodied electrodes (1) used in torches with a liquid cooling system and the copper-bodied electrodes used in air-cooled mechanized system torches.

[0044] The fact that the concave / convex emitter cutter tip (3) also results in lower costs in terms of manufacturing process time is much more advantageous compared to a long-life electrode.

[0045] A problem in plasma cutting is angled and burr cutting in the metal cutting of copper bodied electrodes; the cutting quality obtained and the cutting angle is low when the cutting of the copper-bodied electrode is started; there is no or almost no burr on the lower cutting surface of the cut surface; these negativities increase towards the end of the copper-bodied electrode life, because the tip of the electrode (1) being produced enlarges gradually by melting in the form of a bowl and the kerf gap gradually increases.

[0046] Thanks to the cooling surface increase channels (3a, 3b) made with the invention, better cooling is achieved, the life of the copper-bodied electrode (1) becomes 2 fold or more, the part enlarging by melting in the form of a bowl in a lower level and at a longer time further reduces these problems, and this allows to obtain a better quality cut.

[0047] If the bowl becomes too large, the milling operator must reduce cutting speed, resulting in longer cutting times and increased milling costs.

[0048] Due to the higher thermal and electrical conductivity of silver compared to copper, electrodes made of silver and / or silver / copper and / or copper-silver alloys tend to have a slightly longer life than electrodes made of copper, especially at high ampere hours.

[0049] However, the cost of silver is much higher than the cost of copper, which significantly increases the cost of the electrode.

[0050] The cooling surface increased flow paths (3a, 3b) of the present invention create an alternative to copper body cutting electrodes (1) whose body is made of copper, with a lifespan that is more than doubled, which reduces the cost of copper body electrodes.

[0051] It has long been known by manufacturers that emitter cutter tips (3) used in plasma cutting copper electrodes generally include cylindrical sections or other geometric shapes (e.g., conical) and similar geometries, but no information or peers have had the idea of ​​the present invention below. thanks to the heat transfer surface increase channels (3a) extending in the bowl (3c) consisting of the same cross section obtained by equally spaced concaves / convexities opening parallel to one another and / or at the same angle to one another, so as to provide the highest surface increase; and The extension of the copper electrode (1) is achieved thanks to the highest heat transfer surface increasing flow passages (3b) which run parallel to each other from the outer diameter on the upper section of the emitter cutter tip (3), are of the same cross section and decrease at equal intervals towards the center (providing a geometric structure which allows a reduction in the mass lost by evaporation of the phase transition).

Claims

1. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the copper electrode having an increased cooling surface and therefore an increased lifespan and efficiency; The emitter cutter tip has a surface-increasing flow passage (3a) with a concave / convex surface on its side and a surface-increasing flow passage (3b) with a concave / convex surface on its top surface, and has a diameter that expands in a bowl shape from its outer diameter to its end; and 1. A plasma cutting torch copper electrode comprising: a downstream electrode body (2) carrying an emitter cutter tip (3) having a cavity (4) in which the emitter cutter tip (3) is fixed.

2. 2. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the copper electrode having an increased cooling surface and an increased lifespan and efficiency thereof, according to claim 1; A copper electrode for a plasma cutting torch, characterized in that the emitter cutter tip (3) is made of tungsten, hafnium, or zirconium, which is made of an arc (arc: electric arc discharge) formed by exposure to the suction force generated by an arc plasma jet during operation of the copper electrode body (1), and which performs a metal cutting process, and has a surface-increasing flow path (3a) with a concave / convex formed on its side surface and a surface-increasing flow path (3b) with a concave / convex formed on its upper surface, which ensures further cooling of the emitter cutter tip (3) and does not melt rapidly even when exposed to high heat during operation, allowing the same to be used for a longer period of time.

3. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are extended with an increased cooling surface according to claim 1 or 2; A plasma cutting torch copper electrode, characterized in that a profile is formed during the manufacture of said emitter cutter tip (3), by adding the diameter of the bowl tip level that can be opened according to the amperage and the indentation / protrusion depth tolerance at the bowl depth (A) to the emitter cutter tip (3).

4. A plasma cutting torch copper electrode connecting an emitter cutter tip (3) for a plasma cutting torch and a copper electrode body, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; A copper electrode for a plasma cutting torch, characterized in that it has an emitter cutter tip (3) with an enlarged diameter (3c) in proportion to the depth of the indentations / protrusions that are opened at equal intervals from the outer diameter of said emitter cutter tip (3) at the level of the bowl depth (A) to the flat or conical end of the emitter cutter tip (3) in the upward direction.

5. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; 1. A plasma cutting torch copper electrode, characterized in that emitter cutter tip (3) has a cavity (4) secured to the copper-bodied electrode body with a headroom depending on the geometrical section of the channels (3a, 3b) opened by knurling, the number of channels, the depth to which they will be driven, and the amount of sawdust to be scraped and swept during driving.

6. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; A copper electrode for a plasma cutting torch, characterized in that the copper electrode for use in a torch having a liquid cooling system and the copper electrode for use in a torch having an air cooling mechanism system have a long-life emitter cutter tip (3).

7. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; It has surface-increasing channels (3a, 3b) with recesses / protrusions on its (cavity) side and top surfaces, as well as on the side and top surfaces of the (insertion) emitter cutter tip (3), and 1. A copper electrode for a plasma cutting torch, comprising: an emitter cutter tip (3) having an increased service life due to an enlarged diameter (3c) of said emitter cutter tip, said tip expanding in a bowl-shaped configuration from the outer diameter to the tip. (Reference English: characterized in that it has surface increase channels (3a, 3b) formed with indentations / protrusions on the side and upper surfaces thereof as well as (insert) emitter cutter tip's (3) side and upper surfaces and the emitter cutter tip (3) of which life is increased by enlarging the diameter (3c) of the emitter cutter tip enlarging in the form of a bowl from the outer diameter to the tip)

8. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; A copper electrode for a plasma cutting torch, characterized in that it has an emitter cutter tip (3) that can be formed with any number of indentations / protrusions according to the diameter(3c) of the emitter cutter tip (3) calculated according to the maximum cutting amperage, with any suitable geometric profile section to create the highest cooling surface increase, and with any suitable geometric extensions.

9. A plasma cutting torch copper electrode for connecting an emitter cutter tip and a copper electrode body for a plasma cutting torch, the life and efficiency of which are increased with the increase in the cooling surface according to claim 1; It has cooling surface increasing passages (3a, 3b) formed by concave / convex on the side and top surfaces of the emitter cutter tip (3), the emitter cutter tip being fixed in a cavity (4) in which the copper electrode body is fixed, and from the extremely severe point where the emitter cutter tip (3) starts cutting, the emitter cutter tip (3) having the increased surface area, thanks to this increased cooling surface, further increases cooling, reduces evaporation, extends the life, and as a result, extends the service life. (Reference English: characterized in that it has, with cooling surface increase channels (3a, 3b) formed by indentations / protrusions on the side and upper surfaces of the emitter cutter tip (3) secured to the cavity (4) where the emitter cutter tip is secured the copper-bodied electrode body, an emitter cutter tip (3) having surface increase from the most extreme point where the emitter cutter tip (3) starts cutting, much more cooling thanks to this cooling surface increase, thusly reduced evaporation and extended life, and thus extended service life.)

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