Plasma emitter with composite structure and plasma electrode head adapted for the plasma emitter

Abstract

The utility model belongs to the field of plasma cutting technology, and in particular discloses a plasma emitter with a composite structure. The plasma emitter is formed by tightly coating a coating layer made of pure copper or copper alloy on the outside of a plasma emission column made of pure hafnium or pure zirconium. When it is used, the coating layer is in direct contact with the substrate of the plasma electrode head. Due to the same or similar cooling coefficients, no gap will be generated between the two after insertion and cooling, thereby increasing the cooling contact area between the two, greatly overcoming the problem of insufficient cooling contact area between the two due to different cooling coefficients of materials in the prior art, and greatly improving the disadvantage of the low service life of current conventional plasma emitters, with an average service life increased by more than 20%. The utility model also discloses a plasma electrode head based on the above-mentioned plasma emitter. Based on the composite structure, the plasma electrode head can show good cutting efficiency in actual cutting applications.

Description

Technical Field

[0001] The utility model belongs to the technical field of plasma cutting, and specifically provides a plasma emitter for a plasma cutting machine with a composite structure, and a plasma electrode head adapted to the plasma emitter. Background Art

[0002] Plasma cutting technology has become a major cutting method for metal materials, especially non-ferrous metals and stainless steel. Compared with other cutting methods, plasma cutting greatly improves cutting quality and cutting efficiency.

[0003] The electrode head is the most consumed part of the plasma cutting machine. The quality of the electrode head directly affects the cutting quality, efficiency and cost of plasma cutting. Therefore, improving the quality of the electrode head is a very critical technical point. Among them, the service life of the electrode head is an important parameter of the quality of the electrode head.

[0004] The plasma electrode heads currently used for plasma cutting machines are mostly composed of a copper or copper alloy substrate and a plasma emitter at the head end, and the emitter is mainly made of pure hafnium or pure zirconium, and is mostly cylindrical. However, this combination of plasma emitters has a short lifespan and requires frequent replacement of the plasma emitter, which greatly affects the plasma cutting efficiency and increases the processing cost. Utility Model Content

[0005] The inventor of the utility model found in the long-term research on plasma electrode heads that even if the plasma emitter is directly processed by purchasing imported pure hafnium or pure zirconium raw materials, its service life cannot be improved. Analysis shows that this is because the plasma emitter is generally combined with the substrate by inlaying, brazing, extrusion or other methods, but the cooling coefficients of the two materials are different. After processing and cooling, a gap is generated between the surface of the emitter and the inner wall of the substrate, which greatly reduces the cooling contact area between the two, and thus shortens the service life of the plasma emitter.

[0006] To this end, the inventor of the utility model proposes a plasma emitter with a composite structure. The plasma emitter is externally composited with a composite layer made of copper or copper alloy, and is cooled by contact between the composite layer and the substrate. Compared with the plasma emitter generally made of pure hafnium or pure zirconium in the prior art, the plasma emitter can overcome the gap between the plasma emitter and the substrate due to different cooling coefficients, that is, it has a larger cooling contact area with the substrate, thereby achieving the effect of improving the service life.

[0007] The utility model specifically adopts the following technical solutions:

[0008] A plasma emitter with a composite structure comprises a plasma emission column and a coating layer tightly coating the outside of the plasma emission column; wherein the coating layer is made of copper or copper alloy.

[0009] The ratio between the thickness of the coating layer and the dimension of the plasma emission column in the thickness direction of the coating layer is 1 to 2:2.

[0010] Preferably, the cladding layer is a structural layer tightly wrapped around the outside of the plasma emitting column by a cold working and drawing technique.

[0011] Specifically, the cross-sectional shape of the plasma emission column in a direction perpendicular to the height of the plasma emission column is circular or polygonal.

[0012] Preferably, the polygon is a triangle, or a polygonal star with at least three sharp angles, such as a triangular star, a quadrangular star, a pentagram, etc.; and the triangle can be an equilateral triangle, an isosceles triangle, a right triangle or an irregular triangle, and the polygonal star can be a regular shape or an irregular shape.

[0013] Furthermore, the plasma emission columns have the same size in the height direction, or the bottom surface has a larger size than the top surface in the height direction.

[0014] Furthermore, the plasma emitter is cylindrical (ie, the sizes are equal in height direction) or table-shaped (ie, the bottom surface has a larger size than the top surface in height direction).

[0015] Furthermore, when it is in a terrace shape, its side surface may be a continuous surface with a uniform transition from the bottom surface to the top surface, or may be a continuous surface with a step-like transition from the bottom surface to the top surface.

[0016] The bottom surface refers to the end of the plasma emitter inserted into the substrate, and the top surface refers to the end of the plasma emitter away from the substrate and used to approach the object to be cut.

[0017] Preferably, the number of plasma emitting columns in each plasma emitting body is at least two.

[0018] Furthermore, the plasma emission column is made of pure zirconium or pure hafnium.

[0019] Based on the above plasma emitter, the utility model also provides a plasma electrode head adapted to the above plasma emitter.

[0020] A plasma electrode head comprises a substrate made of copper or copper alloy, wherein the substrate has a receiving cavity for inserting a plasma emitter; wherein the shape of the inner wall of the receiving cavity is adapted to the shape of the plasma emitter with a composite structure.

[0021] Furthermore, there is a transition fit between the plasma emitter and the substrate.

[0022] Specifically, transition fit refers to an interference fit or partial gap between the two.

[0023] Preferably, the number of the accommodating cavities is at least 2.

[0024] Compared with the conventional plasma emitter made of pure hafnium or pure zirconium, the above-mentioned plasma emitter provided by the utility model is tightly coated with a coating layer made of pure copper or copper alloy on its outside. When it is used in conjunction with the substrate of the plasma electrode head, the coating layer is in direct contact with the substrate. Due to the same or similar cooling coefficients, no gap will be generated between the two after the plasma emitter is inserted and cooled, thereby increasing the cooling contact area between the plasma emitter and the inner wall of the substrate, thereby greatly overcoming the problem of insufficient cooling contact area between the plasma emitter and the substrate in the prior art due to different cooling coefficients of the materials, and greatly improving the disadvantage of the current conventional plasma emitter with a low service life, with an average service life increased by more than 20%. The plasma electrode head based on the above-mentioned plasma emitter with a composite structure has a longer service life based on the plasma emitter, and can also avoid frequent replacement in application, showing excellent cutting efficiency in actual cutting applications, and greatly reducing processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a side sectional view of a plasma electrode head according to Example 1 of the utility model;

[0026] Figure 2 is a side cross-sectional view of a substrate in a plasma electrode head according to Example 1 of the utility model;

[0027] Figure 3 is a schematic structural diagram of a plasma emitter according to Embodiment 1 of the present utility model;

[0028] Figure 4 is a top view of a plasma emitter according to embodiment 1 of the utility model;

[0029] Figure 5 is a side sectional view of a plasma electrode head according to Embodiment 2 of the present utility model;

[0030] Figure 6 is a schematic structural diagram of a plasma emitter according to Embodiment 2 of the present utility model;

[0031] Figure 7 is a top view of a plasma emitter according to embodiment 2 of the present utility model;

[0032] Figure 8 is a schematic cross-sectional view in the height direction of another variable structure of the plasma emitter according to Embodiment 2 of the present utility model;

[0033] Fig. 9 is a schematic structural diagram of a plasma emitter according to Embodiment 3 of the present utility model;

[0034] Fig.10 is a schematic structural diagram of a plasma emitter according to Embodiment 4 of the present utility model;

[0035] Fig.11 is a top view of a plasma emitter according to Embodiment 4 of the present utility model;

[0036] Fig.12 is a top view of a plasma emitter according to Example 5 of the utility model;

[0037] Fig.13 is a top view of a plasma emitter according to Example 6 of the utility model;

[0038] Fig.14 is a top view of a plasma emitter according to Example 7 of the utility model;

[0039] Fig.15 is a top view of a plasma emitter according to Example 8 of the utility model;

[0040] Fig.16 It is a left side view of the plasma electrode head according to Example 9 of the utility model;

[0041] Fig.17 It is a left side view of the substrate in the plasma electrode head according to Example 9 of the utility model;

[0042] Fig.18 It is a left side view of the plasma electrode head according to the embodiment 10 of the utility model;

[0043] Fig.19 It is a left view of the substrate in the plasma electrode head according to Example 10 of the utility model. DETAILED DESCRIPTION

[0044] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that corresponding reference numerals throughout the drawings indicate identical or corresponding parts and features. It should also be understood that the various cross-hatching patterns used in the drawings are not intended to limit specific materials or locations that may be used in the present disclosure, and that the cross-hatching patterns are used only for clarity purposes to distinguish adjacent or mating parts shown in the drawings.

[0045] Example 1

[0046] Combination Figure 1 and Figure 2 This embodiment provides a plasma electrode head for a plasma cutting machine, which includes a substrate 1. The end of the substrate 1 has an outwardly open accommodating cavity 11, and a plasma emitter 2 is embedded in the accommodating cavity 11.

[0047] It should be noted that the base 1 also includes a housing, an insulator, a plasma gas pipe, a coolant supply pipe, a cathode and other necessary components for achieving plasma transmission, cutting, cooling and the like, which are not described or illustrated one by one here. Those skilled in the art may refer to the structure and components provided in any existing plasma electrode head.

[0048] Specifically, refer to Figure 3 and Figure 4 As shown, the plasma emitter 2 includes a plasma emission column 21 located at the core, and a cladding layer 22 tightly covering the plasma emission column 21 .

[0049] In this embodiment, the plasma emission column 21 is made of pure hafnium, and the cladding layer 22 is made of copper alloy.

[0050] Specifically, the plasma emitting column 21 is a hafnium wire with a bottom diameter d1 of about 2 mm, and the thickness d2 of the coating layer 22 is about 2 mm; that is, the total bottom diameter D of the plasma emitting body 2 is about 6 mm.

[0051] In this embodiment, the plasma emitter 2 is manufactured by the following process.

[0052] First, the surface of the hafnium wire is cleaned by ultrasonic cleaning or other treatments to remove impurities and oil film on the surface.

[0053] Then, a layer of copper tube of equal length is coated on the outside of the hafnium wire, and the coated material is pointed by a pointing machine, and then subjected to a cycle of roller die drawing and vacuum treatment to obtain a hafnium-copper composite rod of a predetermined size.

[0054] Finally, the hafnium-copper composite rod is subjected to surface polishing treatment, and after the size and composite condition are inspected, it is punched and pelletized by a punching machine, and finally the surface is polished again to obtain a finished plasma emitter.

[0055] Example 2

[0056] The similarities between this embodiment and embodiment 1 are not described here in detail, and only the differences from embodiment 1 are described. The difference between this embodiment and embodiment 1 is that, specifically refer to Figure 5 to Figure 7In this embodiment, the plasma emitter 2 is truncated cone-shaped as a whole; wherein the plasma emitter column 21 made of pure hafnium is consistent with that in Embodiment 1, and the coating layer 22 made of copper alloy is gradually thickened from the top end (i.e., the end of the plasma emitter 2 away from the substrate and close to the surface of the object to be cut) to the bottom end (i.e., the end of the plasma emitter 2 inserted into the substrate).

[0057] That is, in this embodiment, the side surface of the plasma emitter 2 is a continuous surface that uniformly transitions from the bottom surface to the top surface; of course, the side surface of the plasma emitter 2 in this embodiment can also be as follows: Figure 8 A continuous surface with a stepped transition from the bottom surface to the top surface as shown in FIG.

[0058] Corresponding to the plasma emitter 2, the receiving cavity ( Figure 5 The shape of the device (not shown) is also a truncated cone whose size gradually increases from the opening to the bottom.

[0059] Specifically, the plasma emission column 21 is a hafnium wire with a bottom diameter d1 of about 2 mm, and the top thickness d of the coating layer 22 is 21 About 1mm, bottom thickness d 22 That is, the total diameter D1 of the top surface of the plasma emitter 2 is about 4 mm, while the total diameter D2 of the bottom surface is about 6 mm.

[0060] It should be noted that Figure 7 The top view of the plasma emitter 2 is a view obtained by placing the bottom of the plasma emitter 2 on a plane.

[0061] Example 3

[0062] The similarities between this embodiment and embodiment 1 are not described here, and only the differences from embodiment 1 are described. The difference between this embodiment and embodiment 1 is that the plasma emission column 21 is in the shape of a triangular prism; Fig. 9 shown.

[0063] Thus, compared with a general cylindrical plasma emission column, the triangular prism-shaped plasma emission column 21 has a larger surface area than the cylindrical one under the premise of equal pure hafnium dosage, thereby increasing the contact area between the plasma emission column 21 and the coating layer 22 covering it. The great contact between the coating layer 22 and the substrate, which are made of the same material, can ensure that the plasma emission column 21 receives the cooling treatment applied by the coolant supply pipe and other components in the substrate to a great extent. The larger cooling contact area can increase the service life of the plasma emission body 2.

[0064] Example 4

[0065] The similarities between this embodiment and embodiment 1 are not described here, and only the differences from embodiment 1 are described. The difference between this embodiment and embodiment 1 is that the plasma emission column 21 has a triangular star-shaped cross section in a direction perpendicular to its height, and has the same size at the top end (referring to the end away from the substrate) and the bottom end (referring to the end inserted into the substrate); Fig.10 and Fig.11 shown.

[0066] Example 5

[0067] The similarities between this embodiment and embodiment 1 are not described here, and only the differences from embodiment 1 are described. The difference between this embodiment and embodiment 1 is that the plasma emission column 21 has a polygonal star-shaped cross section in a direction perpendicular to its height, and has the same size at the top (referring to the end away from the substrate) and the bottom (referring to the end inserted into the substrate); Fig.12 shown.

[0068] Example 6

[0069] The similarities between this embodiment and the first embodiment are not described here, and only the differences from the first embodiment are described. The difference between this embodiment and the first embodiment is that the plasma emission column 21 is in the shape of a table with a five-pointed star cross section, that is, the cross-sectional shape of the plasma emission column 21 on a plane perpendicular to its height is a five-pointed star, and its top and bottom have different sizes (the bottom is larger); Fig.13 shown.

[0070] Specifically, the five-pointed star shape of the bottom cross-section of the plasma emission column 21 is larger than the five-pointed star shape of the top cross-section. Thus, when the coating layer 22 covers it, the contact area between the plasma emission column 21 and the coating layer 22 can be further increased compared to the shape of the bottom and the top with the same size, thereby increasing the cooling contact area between the plasma emission column 21 and the substrate during use, thereby increasing the service life of the plasma emission column 21.

[0071] In this embodiment, the plasma emission column 21 is made of pure zirconium, and the cladding layer 22 is made of pure copper.

[0072] Example 7

[0073] The similarities between this embodiment and the first embodiment are not described here, and only the differences from the first embodiment are described. The difference between this embodiment and the first embodiment is that the plasma emitter 2 includes four plasma emission columns 21 located in the core, and a coating layer 22 tightly covering the outside of these plasma emission columns 21; and these plasma emission columns 21 have a polygonal star-shaped cross-section in a direction perpendicular to their height, and have the same size at the top (referring to the end away from the substrate) and the bottom (referring to the end inserted into the substrate); Fig.14 shown.

[0074] In this embodiment, the plasma emitter 2 is manufactured by the following process.

[0075] First, the hafnium wire is drawn to obtain a hafnium wire with a special cross-section (the cross-section shape is a polygonal star).

[0076] Then, the surface of the special-section hafnium wire is cleaned by ultrasonic cleaning or other treatments to remove impurities and oil film on the surface.

[0077] In the third step, four hafnium wires with special cross-sections are arranged and fixed in a casting cavity, the shape of which is consistent with the shape of the preformed plasma emitter.

[0078] Finally, molten copper is poured into the casting cavity, and after cooling, a plasma emitter product is formed, which is formed by a copper coating layer covering four hafnium wires with a polygonal star-shaped cross-section.

[0079] Example 8

[0080] The similarities between this embodiment and embodiment 1 are not described here, and only the differences from embodiment 1 are described. The difference between this embodiment and embodiment 1 is that the plasma emitter 2 includes two plasma emission columns 21 located at the core, and a coating layer 22 tightly covering the outside of these plasma emission columns 21; and these plasma emission columns 21 are cylindrical; Fig.15 shown.

[0081] In this embodiment, the plasma emitter is manufactured by a process similar to that in Embodiment 7 (drawing hafnium wire - pouring molten copper).

[0082] Compared with the solution of only setting one plasma emission column 21 in a plasma emission body 2, setting more plasma emission columns 21 in the above-mentioned embodiments 7 and 8 can provide a larger contact area between them and the coating layer 22, thereby increasing the cooling contact area between them and the substrate during application and improving the cutting efficiency.

[0083] Example 9

[0084] This embodiment provides a plasma electrode head for a plasma cutting machine, which includes a substrate 1 as described in Embodiment 1, which will not be described again here, and the side cross-sectional view of the plasma electrode head will not be shown.

[0085] Specifically, combined Fig.16 and Fig.17 As shown, the end of the base body 1 has four receiving cavities 11 , and a plasma emitter 2 is embedded in each receiving cavity 11 .

[0086] The plasma emitter 2 has the same structure as the plasma emitter in Example 5, that is, it includes a plasma emitter column 21 made of pure hafnium and a coating layer 22 made of copper alloy tightly covering the outside of the plasma emitter column 21; and the plasma emitter column 21 has a polygonal star-shaped cross-section in a direction perpendicular to its height, and has the same size at the top end (referring to the end away from the substrate) and the bottom end (referring to the end inserted into the substrate).

[0087] Example 10

[0088] The similarities between this embodiment and embodiment 9 are not described here, and only the differences from embodiment 9 are described. The difference between this embodiment and embodiment 9 is that the end of the substrate 1 has two accommodating cavities 11 open outward, and a plasma emitter 2 is embedded in each accommodating cavity 11; and each plasma emitter 22 includes two cylindrical plasma emission columns 21 located at the core, and a coating layer 22 tightly covering the outside of these plasma emission columns 21; refer to Fig.18 and Fig.19 shown.

[0089] In this embodiment, the coating layer 22 in the plasma emitter is manufactured by a casting process similar to that in the seventh embodiment.

[0090] The plasma emitter provided by the utility model, wherein the number of plasma emission columns is obviously not limited to those shown in the above-mentioned embodiments 7 and 8, and may also be 3, 5 or even more. At the same time, when the cross-sectional shape of the plasma emission column is a polygonal star, it is obviously not limited to those shown in the above-mentioned embodiments 4 to 7 and embodiment 9, and polygonal stars with other numbers of sharp corners are also possible, such as four-pointed stars, six-pointed stars, eight-pointed stars, etc.; and these polygonal stars are not limited to the regular shapes shown in the above-mentioned embodiments (that is, each sharp corner and the angle formed between them are equal), and may also be irregular polygonal stars, the main purpose of which is that the polygonal star shape can obtain a larger contact area with the coating layer under equal volume, thereby improving the cooling conduction efficiency during the application process and improving the service life of the plasma emitter.

[0091] At the same time, the number of plasma emitters inserted in the plasma electrode head provided by the utility model is not limited to those described in the above-mentioned embodiments 9 to 10, and can also be 3, 5 or even more; and when multiple (at least 2) plasma emitters are inserted in the plasma electrode head, the size and / or shape of each plasma emitter and the plasma emission column contained therein can be the same or different.

[0092] As to the number, size and shape of the plasma emitters inserted in the plasma electrode head, as well as the number, size and cross-sectional shape of the plasma emission columns contained in each plasma emitter, those skilled in the art can make adaptive adjustments according to actual effect requirements or the degree that the process can achieve.

[0093] In the above embodiments, for the plasma emitting column with a polygonal star-shaped cross-section, it can be processed by rolling, drawing and other processes; and for the plasma emitting column with a polygonal star-shaped cross-section covered by a coating layer, it can be processed by rolling, drawing, casting, filling and other processes. Obviously, for the plasma emitting column, the cross-sectional shape with more sharp corners will obtain a larger contact area with the coating layer under equal volume, but it will also increase the processing difficulty accordingly, and the processing difficulty of the substrate adapted thereto will also increase. Therefore, in actual application, it is advisable for those skilled in the art to simplify the cross-sectional shape as much as possible to meet product requirements.

[0094] The description of the disclosure is merely exemplary in nature and thus variations that do not depart from the gist of the disclosure are intended to be within the purview of the disclosure and are not to be regarded as a departure from the spirit and scope of the disclosure.

Claims

1. A plasma emitter with a composite structure, characterized in that: The invention comprises a plasma emission column and a coating layer tightly coating the outside of the plasma emission column; wherein the coating layer is made of copper or copper alloy.

2. The plasma emitter according to claim 1, characterized in that: The ratio between the thickness of the cladding layer and the dimension of the plasma emission column in the thickness direction of the cladding layer is 1 to 2:

2.

3. The plasma emitter according to claim 1 or 2, characterized in that: The cross-sectional shape of the plasma emission column in a direction perpendicular to the height of the plasma emission column is circular or polygonal.

4. The plasma emitter according to claim 3, characterized in that: The polygon is a triangle or a polygonal star with at least three sharp angles.

5. The plasma emitter according to claim 4, characterized in that The polygon is a regular shape or an irregular shape.

6. The plasma emitter according to claim 4, characterized in that: The plasma emission columns have equal dimensions in the height direction, or the bottom dimension in the height direction is larger than the top dimension.

7. The plasma emitter according to claim 3, characterized in that: The plasma emitter is cylindrical or table-shaped.

8. The plasma emitter according to claim 7, characterized in that When the plasma emitter is in a table shape, its side surface is a continuous surface that transitions uniformly from the bottom surface to the top surface, or a continuous surface that transitions in a step-like manner from the bottom surface to the top surface.

9. The plasma emitter according to claim 1 or 2, characterized in that: The number of plasma emission columns in each of the plasma emission bodies is at least 2.

10. A plasma electrode head, comprising a substrate made of copper or copper alloy, wherein the substrate has a receiving cavity opening outward; characterized in that: The plasma electrode head further comprises a plasma emitter as claimed in any one of claims 1 to 9.

11. The plasma electrode head according to claim 10, characterized in that: The number of the accommodating cavities is at least 2.

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