EP2804450A2 - Insulating member for a plasma torch consisting of one or several parts, in particular a plasma cutting torch, and assemblies and plasma torch equipped with the same - Google Patents

Abstract

One or more parts insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, characterized in that it consists of an electrically non-conductive and heat well conductive material or at least a part thereof from an electrically non conductive and heat well conductive material, and assemblies and plasma torches with the same, as well as methods of machining, plasma cutting and plasma welding.

Description

The present invention relates to a mono- or multi-part insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, arrangements and plasma torch with such an insulating part, plasma torch with such an arrangement and method for machining a workpiece a thermal plasma, plasma cutting and plasma welding.

Plasma torches are generally used for the thermal processing of electrically conductive materials, such as steel and non-ferrous metals. Plasma welding torches are used for welding and plasma cutting torches for cutting electrically conductive materials such as steel and non-ferrous metals. Plasma torches usually consist of a torch body, an electrode, a nozzle and a holder for it. Modern plasma torches also have a nozzle cap mounted above the nozzle. Often a nozzle is fixed by means of a nozzle cap.

Depending on the type of plasma torch, the components which wear out due to the high thermal load caused by the operation of the plasma torch are, in particular, the electrode, the nozzle, the nozzle cap, the nozzle protection cap Nozzle cap holder and the plasma gas guide and secondary gas guide parts. These components can be easily changed by an operator and thus be referred to as wear parts.

The plasma torches are connected via lines to a power source and a gas supply, which supply the plasma torch. Furthermore, the plasma torch may be connected to a cooling means for a cooling medium, such as a cooling liquid.

Plasma cutting torches are subject to particularly high thermal loads. This is due to the strong constriction of the plasma jet through the nozzle bore. In comparison to plasma welding, small holes are used in relation to the cutting current, so that high current densities of 50 to 150 A / mm ² in the nozzle bore, high energy densities of approx. 2x10 ⁶ W / cm ² and high temperatures of up to 30,000 K are generated , Furthermore, in the plasma cutting torch higher gas pressures, usually up to 12 bar, used. The combination of high temperature and high kinetic energy of the plasma gas flowing through the nozzle bore leads to melting of the workpiece and expulsion of the melt. The result is a kerf and the workpiece is separated. In plasma cutting, oxidizing gases are often used to cut unalloyed steels. This also leads to a high thermal load on the wearing parts and the plasma cutting torch.

On the plasma cutting torch will be discussed in more detail below.

Between the electrode and the nozzle flows a plasma gas. The plasma gas is passed through a gas guide part, which may also be multi-part. As a result, the plasma gas can be targeted. Often it is offset by a radial and / or axial displacement of the openings in the plasma gas guide part in rotation about the electrode. The plasma gas guide member is made of electrically insulating material because of the electrode and the nozzle must be electrically insulated from each other. This is necessary because the electrode and the nozzle have different electrical potentials during operation of the plasma cutting torch. To operate the plasma cutting torch, an arc is generated between the electrode and the nozzle and / or the workpiece which ionizes the plasma gas. To ignite the arc, a high voltage can be applied between the electrode and the nozzle, which ensures a pre-ionization of the distance between the electrode and nozzle and thus the formation of an arc. The arc burning between the electrode and the nozzle is also called a pilot arc.

The pilot arc exits through the nozzle bore and strikes the workpiece, ionizing the distance to the workpiece. As a result, the arc can form between the electrode and the workpiece. This arc is also called the main arc. During the main arc, the pilot arc can be switched off. But he can also continue to operate. In plasma cutting, this is often switched off so as not to burden the nozzle even more.

In particular, the electrode and the nozzle are subjected to high thermal stress and must be cooled. At the same time, they must also conduct the electrical current needed to form the arc. Therefore, for good heat and electrically conductive materials, usually metals, for example copper, silver, aluminum, tin, zinc, iron or alloys, in which at least one of these metals is included, are used.

The electrode often consists of an electrode holder and an emissive insert made of a material having a high melting temperature (> 2000 ° C) and a lower electron work function than the electrode holder. As materials for the emission use when non-oxidizing plasma gases, such as argon, hydrogen, nitrogen, helium and mixtures thereof, tungsten and the use of oxidizing gases, such as oxygen, air and mixtures thereof, nitrogen-oxygen mixture and mixtures used with other gases, hafnium or zirconium. The high-temperature material can be fitted into an electrode holder, which consists of good heat and good electrical conductivity material, for example, be pressed with positive and / or adhesion.

The cooling of the electrode and nozzle can be effected by gas, for example the plasma gas or a secondary gas flowing along the outside of the nozzle. More effective, however, is the cooling with a liquid, for example water. The electrode and / or nozzle are often cooled directly with the liquid, i. the liquid is in direct contact with the electrode and / or the nozzle. To guide the cooling liquid around the nozzle, there is a nozzle cap around the nozzle, the inner surface of which forms with the outer surface of the nozzle a coolant space in which the coolant flows.

In modern plasma cutting burners is additionally located outside of the nozzle and / or the nozzle cap in addition a nozzle cap. The inner surface of the nozzle cap and the outer surface of the nozzle or the nozzle cap form a space through which a secondary or inert gas flows. The secondary or inert gas exits the bore of the nozzle cap and envelops the plasma jet and provides for a defined atmosphere around it. In addition, the secondary gas protects the nozzle and the nozzle cap from arcs that may form between it and the workpiece. These are called double arcs and can damage the nozzle. In particular, when piercing the workpiece, the nozzle and the nozzle cap are heavily loaded by hot high-spraying of material. The secondary gas, whose volume flow during piercing can be increased compared to the value during cutting, keeps the high-spraying material away from the nozzle and the nozzle cap and thus protects against damage.

The nozzle cap is also subjected to high thermal loads and must be cooled. Therefore, for good heat and electrically conductive materials, usually metals, for example copper, silver, aluminum, tin, zinc, iron or alloys, in which at least one of these metals is included, are used.

The electrode and the nozzle can also be cooled indirectly. They stand with a component which consists of a good heat and good electrical conductivity material, usually a metal, for example copper, silver, aluminum, tin, zinc, iron or alloys in which at least one of these metals is included , by contact in contact. This component in turn is cooled directly, that is, it is in direct contact with the most-flowing coolant. These components can simultaneously serve as a holder or receptacle for the electrode, the nozzle, the nozzle cap or the nozzle cap and remove the heat and the current.

There is also the possibility that only the electrode or only the nozzle are cooled with liquid. Especially in this case often occur too high temperatures on the only gas-cooled component, which then quickly wears out or even destroyed. This also leads to large temperature differences between the components in the plasma cutting torch and thus to mechanical stresses and additional stresses.

The nozzle cap is usually cooled only by the secondary gas. Arrangements are also known in which the nozzle protection cap is cooled directly or indirectly by a cooling liquid.

The gas cooling (plasma gas and / or secondary gas cooling) has the disadvantage that it is not effective and the required gas flow rate is very high in order to achieve acceptable cooling or heat dissipation. Plasma cutting torches with water cooling require, for example, gas flow rates of 500 l / h to 4000 l / h, while plasma cutting torches without water cooling require gas flow rates of 5000 to 11000 l / h. These ranges are a function of the cutting currents used, which may, for example, be in a range of 20 to 600 A. At the same time, the volume flow of the plasma gas and / or secondary gas should be selected so that the best cutting results are achieved. Too large volume flows, which are necessary for the cooling but often worsen the cutting result.

In addition, the high gas consumption caused by large volume flows is uneconomical. This is especially true when other gases than air, so for example. Argon, nitrogen, hydrogen, oxygen or helium are used.

The use of a direct water cooling for all wearing parts, however, is very effective, but leads to an increase in the dimensions of the plasma cutting torch, because, for example, the cooling channels are necessary to lead the coolant back to the part to be cooled and back away. In addition, when changing the directly liquid-cooled wearing parts much care is necessary because no coolant as possible between the wearing parts should remain in the plasma cutting torch, as this can lead to damage of the plasma torch when the arc is ignited.

The invention is therefore based on the object to provide for more effective cooling of components, in particular wear parts, a plasma torch.

According to a first aspect, this object is achieved by a single- or multi-part insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, characterized in that it consists of an electrically non-conductive and heat-conducting material or at least a part of which consists of an electrically non-conductive and heat-conductive material. In this case, the expression "electrically non-conductive" should also include that the material of the plasma torch insulating part conducts electricity slightly or negligibly. The insulating part may, for example, be a plasma gas guide part, secondary gas guide part or cooling gas guide part.

Furthermore, this object is achieved according to a second aspect by an arrangement of an electrode and / or a nozzle and / or a nozzle cap and / or a nozzle cap and / or a nozzle cap holder for a plasma torch, in particular a plasma cutting torch, and an insulating part according to one of claims 1 to 12.

According to a third aspect, this object is achieved by an arrangement comprising a receptacle for a nozzle cap holder and a nozzle cap holder for a plasma torch, in particular a plasma cutting torch, characterized in that the receptacle as a preferably in direct contact with the Düsenschutzkappenhalterung insulating part according to one of claims 1 to 12 is formed. For example, the receptacle and the nozzle cap holder can be connected by a thread.

According to another aspect, this object is achieved by an arrangement of an electrode and a nozzle for a plasma torch, in particular a plasma cutting torch, characterized in that between the electrode and the nozzle designed as a plasma gas guide part insulating part according to one of claims 1 to 12, preferably in direct contact with the same, is arranged.

Furthermore, this object is achieved according to a further aspect by an arrangement of a nozzle and a nozzle cap for a plasma torch, in particular a plasma cutting torch, characterized in that between the nozzle and the nozzle cap designed as a secondary gas guide member insulating member according to any one of claims 1 to 12, preferably in direct contact with selbigem, is arranged.

Moreover, according to a further aspect, this object is achieved by an arrangement of a nozzle cap and a nozzle cap for a plasma torch, in particular a plasma cutting torch, characterized in that between the nozzle cap and the nozzle cap as an insulating part according to one of claims 1 to 12, preferably in direct contact with the same, is arranged dissolved.

Furthermore, the present invention provides a plasma torch, in particular plasma cutting torch, comprising at least one insulating part according to one of claims 1 to 12.

In addition, the present invention provides a plasma torch, in particular plasma cutting torch, comprising at least one arrangement according to one of claims 13 to 18 and a method according to claim 24.

In the insulating part can be provided that it consists of at least two parts, wherein one of the parts of an electrically non-conductive and highly heat-conductive material and the other or at least one of the parts of an electrically non-conductive and non-heat conducting material.

In particular, it may be provided that the part of an electrically non-conductive and heat-conductive material has at least one surface acting as a contact surface, which is flush with an immediately adjacent surface of the part of an electrically non-conductive and non-heat conducting material or protrudes beyond this ,

According to a particular embodiment, the insulating part consists of at least two parts, wherein one of the parts of a highly electrically conductive and highly heat-conductive material and the other or at least another of the parts of an electrically non-conductive and heat-conductive material.

In a further embodiment of the invention, the insulating part consists of at least three parts, wherein one of the parts of a highly electrically conductive and highly heat-conductive material, another of the parts of an electrically non-suffering and heat-conductive material and another of the parts of a electrically non-conductive and heat non-conductive material.

Advantageously, the electrically non-conductive and heat-conductive material has a thermal conductivity of at least 40 W / (m * K), preferably at least 60 W / (m * K) and more preferably at least 90 W / (m * K), more preferably at least 120 W / (m * K), more preferably at least 150 W / (m * K) and even more preferably at least 180 W / (m * K).

Conveniently, the electrically non-conductive and heat-conductive material and / or the electrically non-conductive and non-conductive material has a specific electrical resistance of at least 10 ⁶ Ω * cm, preferably at least 10 ¹⁰ Ω * cm, and / or a voltage breakdown strength of at least 7 kV / mm, preferably at least 10 kV / mm.

Advantageously, the electrically non-conductive and heat-conducting material is a ceramic, preferably from the group of nitride ceramics, in particular aluminum nitride, boron nitride and silicon nitride ceramics, carbide ceramics, in particular silicon carbide ceramics, oxide ceramics, in particular alumina, zirconium oxide and beryllium oxide ceramics , and the silicate ceramics, or plastic, for example, plastic film.

It is also possible to use a combination of an electrically non-conductive and heat-conductive material, for. As ceramic, and another electrically non-conductive material, for. As plastic, in a material, a so-called compound material to use. Such a material can be produced, for example, from powder of both materials by sintering. Ultimately, this compound material must be electrically non-conductive and heat good conductive.

According to a particular embodiment of the invention, the electrically non-conductive and non-conductive material has a thermal conductivity of at most 1 (W / m * K). Advantageously, the parts are positively or non-positively connected by gluing or by a thermal process, for example soldering or welding.

In a particular embodiment of the invention, the insulating part has at least one opening and / or at least one recess and / or at least one groove. This may be the case, for example, when the insulating part is a gas guide part, such as a plasma gas or secondary gas guide part.

In particular, it may be provided that the at least one opening and / or the at least one recess and / or the at least one groove in the electrically non-conductive and heat-conducting material and / or electrically non-conductive and non-heat conducting material and / or electrically well conductive and heat well conductive material is located / located.

In a further particular embodiment of the invention, the insulating part is designed to guide a gas, in particular a plasma, secondary or cooling gas.

In the arrangement according to claim 13 it can be provided that the insulating part is in direct contact with the electrode and / or the nozzle and / or the nozzle cap and / or the nozzle protection cap and / or the nozzle protection cap holder.

Advantageously, the insulating part with the electrode and / or the nozzle and / or the nozzle cap and / or the nozzle cap and / or nozzle protective cap holder positively and / or non-positively, by gluing or by a thermal process, for example, soldering and welding, connected.

In a particular embodiment of the plasma burner according to claim 19, the insulating part or a material which is electrically nonconductive and conducts heat well existing part of the same at least one surface acting as a contact surface, preferably two surfaces, which is in direct contact at least with a surface of a highly electrically conductive component, in particular an electrode, nozzle, nozzle cap, nozzle cap or nozzle cap holder, the plasma torch.

In particular, it may be provided that the insulating part or a part consisting of electrically nonconducting and heat-conducting material has at least two surfaces acting as contact surfaces, at least with a surface of a highly electrically conductive component, in particular an electrode, nozzle, nozzle cap, Nozzle protection cap or nozzle cap holder, the plasma torch and another surface of another electrically good conductive component of the plasma torch is in direct contact.

According to a particular embodiment, the insulating part is a gas guide part, in particular a plasma gas, secondary gas or cooling gas guide part.

Advantageously, the insulating part has at least one surface which, during operation, has direct contact with a cooling medium, preferably a liquid and / or a gas and / or a liquid-gas mixture.

In the method according to claim 24, provision can be made for a laser beam of a laser to be coupled into the plasma torch in addition to the plasma jet.

In particular, the laser may be a fiber laser, diode reader and / or diode-pumped laser.

The invention is based on the surprising finding that by using a material which not only does not conduct electricity electrically but also conducts heat well, a more effective one and cost-effective cooling is possible and smaller and simpler designs of plasma torches are possible and lower temperature differences and thus lower mechanical stresses can be achieved.

The invention provides cooling, at least in one or more particular embodiments, of components, particularly consumables, of a plasma torch that is more effective and / or less expensive and / or results in lower mechanical stresses and / or enables smaller and / or simpler plasma torch designs to simultaneously provide electrical isolation between components of a plasma torch.

• Figur 1 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer ersten besonderen Ausführungsform der Erfindung;
• Figur 2 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer zweiten besonderen Ausführungsform der Erfindung;
• Figur 3 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer dritten besonderen Ausführungsform der Erfindung;
• Figur 4 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer vierten besonderen Ausführungsform der Erfindung;
• Figur 5 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer fünften besonderen Ausführungsform der Erfindung;
• Figur 6 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer sechsten besonderen Ausführungsform der Erfindung;
• Figur 7 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer siebten besonderen Ausführungsform der Erfindung;
• Figur 8 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer achten besonderen Ausführungsform der Erfindung;
• Figur 9 eine Seitenansicht teilweise im Längsschnitt von einem Plasmabrenner gemäß einer neunten besonderen Ausführungsform der Erfindung;
• Figuren 10a und 10b eine Längsschnittansicht sowie eine teilweise geschnittene Seitenansicht von einem Isolierteil gemäß einer besonderen Ausführungsform der Erfindung;
• Figuren 11a und 11b eine Längsschnittansicht sowie eine teilweise geschnittene Seitenansicht von einem Isolierteil gemäß einer weiteren besonderen Ausführungsform der Erfindung;
• Figuren 12a und 12b eine Längsschnittansicht sowie eine teilweise geschnittene Seitenansicht von einem Isolierteil gemäß einer weiteren besonderen Ausführungsform der Erfindung;
• Figuren 13a und 13b eine Längsschnittansicht sowie eine teilweise geschnittene Seitenansicht von einem Isolierteil gemäß einer weiteren besonderen Ausführungsform der Erfindung;
• Figuren 14a und 14b eine Längsschnittansicht sowie eine teilweise geschnittene Seitenansicht von einem Isolierteil gemäß einer weiteren besonderen Ausführungsform der Erfindung;
• Figuren 14c und 14d Ansichten wie die Figuren 14a und 14b, wobei jedoch ein Teil weggelassen ist;
• Figuren 15a und 15b eine Draufsicht teilweise im Schnitt bzw. eine Seitenansicht teilweise im Schnitt von einem Isolierteil, das bspw. in dem Plasmabrenner der Figuren 6 bis 9 eingesetzt ist bzw. eingesetzt werden kann;
• Figuren 16a und 16b eine Draufsicht teilweise im Schnitt bzw. eine Seitenansicht teilweise im Schnitt von einem Isolierteil, das bspw. in dem Plasmabrenner der Figuren 6 bis 9 eingesetzt ist bzw. eingesetzt werden kann;
• Figuren 17a und 17b eine Draufsicht teilweise im Schnitt bzw. eine Seitenansicht teilweise im Schnitt von einem Isolierteil, das bspw. in dem Plasmabrenner der Figuren 6 bis 9 eingesetzt ist bzw. eingesetzt werden kann;
• Figuren 18a bis 18d eine Draufsicht teilweise im Schnitt sowie geschnittene Seitenansichten von einem Isolierteil gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung;
• Figuren 19a bis 19d Schnittansichten von einer Anordnung aus einer Düse und einem Isolierteil gemäß einer besonderen Ausführungsform der Erfindung;
• Figuren 20a bis 20d Schnittansichten von einer Anordnung aus einer Düsenkappe und einem Isolierteil gemäß einer besonderen Ausführungsform der vorliegenden Erfindung;
• Figuren 21a bis 21d Schnittansichten von einer Anordnung aus einer Düsenschutzkappe und einem Isolierteil gemäß einer besonderen Ausführungsform der vorliegenden Erfindung;
• Figuren 22a und 22b Teilschnittansichten einer Anordnung aus einer Elektrode und einem Isolierteil gemäß einer besonderen Ausführungsform der vorliegenden Erfindung; und
• Figur 23 eine Seitenansicht teilweise im Längsschnitt von einer Anordnung aus einer Elektrode und einem Isolierteil gemäß einer besonderen Ausführungsform der vorliegenden Erfindung.

Further features and advantages of the invention will become apparent from the appended claims and the following description, in which reference to the schematic drawings, several embodiments will be described. It shows / show:

• FIG. 1 a side view partially in longitudinal section of a plasma torch according to a first particular embodiment of the invention;
• FIG. 2 a side view partially in longitudinal section of a plasma torch according to a second particular embodiment of the invention;
• FIG. 3 a side view partially in longitudinal section of a plasma torch according to a third particular embodiment of the invention;
• FIG. 4 a side view partially in longitudinal section of a plasma torch according to a fourth particular embodiment of the invention;
• FIG. 5 a side view partially in longitudinal section of a plasma torch according to a fifth particular embodiment of the invention;
• FIG. 6 a side view partially in longitudinal section of a plasma torch according to a sixth particular embodiment of the invention;
• FIG. 7 a side view partially in longitudinal section of a plasma torch according to a seventh particular embodiment of the invention;
• FIG. 8 a side view partially in longitudinal section of a plasma torch according to a eighth particular embodiment of the invention;
• FIG. 9 a side view partially in longitudinal section of a plasma torch according to a ninth particular embodiment of the invention;
• Figures 10a and 10b a longitudinal sectional view and a partially sectioned side view of an insulating part according to a particular embodiment of the invention;
• FIGS. 11a and 11b a longitudinal sectional view and a partially sectioned side view of an insulating part according to another particular embodiment of the invention;
• FIGS. 12a and 12b a longitudinal sectional view and a partially sectioned side view of an insulating part according to another particular embodiment of the invention;
• FIGS. 13a and 13b a longitudinal sectional view and a partially sectioned side view of an insulating part according to another particular embodiment of the invention;
• Figures 14a and 14b a longitudinal sectional view and a partially sectioned side view of an insulating part according to another particular embodiment of the invention;
• Figures 14c and 14d Views like that Figures 14a and 14b but part is omitted;
• FIGS. 15a and 15b a plan view partially in section and a side view partly in section of an insulating part, the example. In the plasma torch of FIGS. 6 to 9 is used or can be used;
• FIGS. 16a and 16b a plan view partially in section and a side view partly in section of an insulating part, the example. In the plasma torch of FIGS. 6 to 9 is used or can be used;
• FIGS. 17a and 17b a plan view partially in section and a side view partly in section of an insulating part, the example. In the plasma torch of FIGS. 6 to 9 is used or can be used;
• FIGS. 18a to 18d a plan view partially in section and sectional side views of an insulating part according to another particular embodiment of the present invention;
• FIGS. 19a to 19d Sectional views of an arrangement of a nozzle and an insulating part according to a particular embodiment of the invention;
• FIGS. 20a to 20d Sectional views of an arrangement of a nozzle cap and an insulating part according to a particular embodiment of the present invention;
• FIGS. 21a to 21d Sectional views of an arrangement of a nozzle cap and an insulating part according to a particular embodiment of the present invention;
• Figures 22a and 22b Partial sectional views of an arrangement of an electrode and an insulating part according to a particular embodiment of the present invention; and
• FIG. 23 a side view partially in longitudinal section of an assembly of an electrode and an insulating part according to a particular embodiment of the present invention.

FIG. 1 shows a liquid-cooled plasma cutting torch 1 according to a particular embodiment of the present invention. It comprises an electrode 2, an insulating part designed as a plasma gas guide part 3 for guiding plasma gas PG and a nozzle 4. The electrode 2 consists of an electrode holder 2.1 and an emissive insert 2.2. The electrode holder 2.2 consists of a good electrical and heat well conductive material, here of a metal, for example copper, silver, aluminum or an alloy in which at least one of these metals is included. The emissive insert 2.2 is made of a material having a high melting temperature (> 2000 ° C). When using non-oxidizing plasma gases (for example argon, hydrogen, nitrogen, helium and mixtures thereof), for example tungsten and when using oxidizing gases (for example oxygen, air, mixtures thereof, nitrogen-oxygen mixture), for example hafnium or Zirconium. The emission insert 2.2 is introduced into the electrode holder 2.1. The electrode 2 is shown here as a flat electrode, in which the emission insert 2.2 does not protrude beyond the surface of the front end of the electrode holder 2.1.

The electrode 2 protrudes into the hollow interior 4.2 of the nozzle 4. The nozzle is screwed with a thread 4.20 in a nozzle holder 6 with internal thread 6.20. Between the nozzle 4 and the electrode 2, the plasma gas guide part 3 is arranged. By doing Plasma gas guide part 3 are bores, openings, grooves and / or recesses (not shown), through which the plasma gas PG flows. By a corresponding arrangement, for example, with a radial offset and / or an inclination to the center line M radially arranged bores, the plasma gas PG can be set in rotation. It serves to stabilize the arc or the plasma jet.

The arc burns between the emissive insert 2.2 and a workpiece (not shown) and is constricted by a nozzle bore 4.1. The arc itself already has a high temperature, which is further increased by its constriction. Temperatures of up to 30,000 K are specified. Therefore, the electrode 2 and the nozzle 4 are cooled with a cooling medium. As a cooling medium, a liquid, in the simplest case water, a gas, in the simplest case, air or a mixture thereof, in the simplest case, an air-water mixture, which is referred to as aerosol, are used. Liquid cooling is considered to be the most effective. In an interior space 2.10 of the electrode 2 is a cooling tube 10 through which the coolant from the coolant flow WV2 through the coolant space 10.10 to the electrode 2 towards the near the emission insert 2.2 and through the space from the outer surface of the cooling tube 10 in the inner surface of the Electrode 2 is formed, is returned to the coolant return WR2.

In this example, the nozzle 4 is cooled indirectly via the nozzle holder 6, to which the coolant is led away again by a coolant space 6.10 (WV1) and via a coolant space 6.11 (WR1). The coolant usually flows at a volume flow of 1 to 10 l / min. The nozzle 4 and the nozzle holder 6 are made of a metal. By means of the external thread 4.20 of the nozzle 4 and the internal thread 6.20 of the nozzle holder 6 formed mechanical contact, the resulting heat in the nozzle 4 is guided into the nozzle holder 6 and discharged through the flowing cooling medium (WV1, WR1).

The formed as a plasma gas guide part 3 insulating part is formed in one piece in this example and consists of an electrically non-conductive and heat-conducting material. By using such an insulating part, an electrical insulation between the electrode 2 and the nozzle 4 is achieved. This is necessary for the operation of the plasma cutting torch 1, namely the high-voltage ignition and the operation of a pilot arc burning between the electrode 2 and the nozzle 4. At the same time heat is conducted between the electrode 2 and the nozzle 4 from the warmer to the colder component through the heat well-conducting designed as a plasma gas guide part 3 insulating member. There is thus an additional heat exchange via the insulating part. The plasma gas guide member 3 is in contact with the electrode 2 and the nozzle 4 by contact via contact surfaces.

In this embodiment, a contact surface 2.3 is, for example, a cylindrical outer surface of the electrode 2 and a contact surface 3.5 is a cylindrical inner surface of the plasma gas-conducting part 3. A contact surface 3.6 is a cylindrical outer surface of the plasma gas-conducting part 3, and a contact surface 4.3 is a cylindrical inner surface of the nozzle 4. Preferably, here a clearance with little play, for example, H7 / h6 used according to DIN EN ISO 286 between the cylindrical inner and outer surfaces, on the one hand to nesting and on the other hand a good contact and thus low thermal resistance and thus to realize good heat transfer. The heat transfer can be improved by applying thermal paste to these contact surfaces. (Note: Even if a thermal grease is used, it should also fall under the term "direct contact".) Then, a fit with a larger game, for example H7 / g6 can be used. Furthermore, the nozzle 4 and the plasma gas guide part 3 here each have a contact surface 4.5 and 3.7, which are annular surfaces here and are in contact with each other by contact. It is a frictional connection between the annular surfaces, which is realized by screwing the nozzle 4 in the nozzle holder 6.

Due to the good thermal conductivity high temperature differences between the nozzle 4 and the electrode 2 can be avoided and thereby caused mechanical stresses in the plasma cutting torch 1 can be reduced.

As a non-electrically conductive and heat-conductive material, a ceramic material is used here by way of example. Particularly suitable aluminum nitride, which according to DIN 60672 has a very good thermal conductivity (about 180 W / (m * K) and a high electrical resistivity (about 10 ¹² Ω * cm).

In FIG. 2 a cylindrical plasma cutting torch 1 is shown, in which the electrode 2 is cooled directly with coolant. The in the FIG. 2 shown indirect cooling of the nozzle 4 via the nozzle holder 6 is not present. The cooling of the nozzle 4 is carried out by heat conduction via a formed as a plasma gas guide part 3 insulating part to the cooled directly with coolant electrode 2 out. By using such an insulating part, the electrical insulation between the electrode 2 and the nozzle 4 is achieved. This is necessary for the operation of the plasma cutting torch 1, namely the high-voltage ignition and the operation of the burning between the electrode 2 and the nozzle 4 pilot arc. At the same time heat is conducted between the electrode 2 and the nozzle 4 from the warmer to the colder component through the heat well-conducting designed as a plasma gas guide part 3 insulating member. Thus, there is an additional heat exchange via the plasma gas guide part 3 between the electrode 2 and the nozzle 4. The plasma gas guide part 3 is in contact with the electrode and the nozzle 4 by contact via contact surfaces.

In this embodiment, a contact surface 2.3 is, for example, a cylindrical outer surface of the electrode 2 and a contact surface 3.5 is a cylindrical inner surface of the plasma gas-conducting part 3. A contact surface 3.6 is a cylindrical outer surface of the plasma gas-conducting part 3, and a contact surface 4.3 is a cylindrical inner surface of the nozzle 4. Preferably, here a clearance with little play, for example, H7 / h6 according to DIN EN ISO 286 between the cylindrical inner and outer surfaces used to on the one hand the nesting and on the other hand a good contact and thus low heat resistance and thus to realize good heat transfer. The heat transfer can be improved by applying thermal paste to these contact surfaces. Then a fit with a larger game, for example H7 / g6 can be used. Furthermore, the nozzle 4 and the plasma gas guide part 3 here each have a contact surface 4.5 or 3.7, which are annular surfaces here and are in contact with each other by contact. It is a frictional connection between the annular surfaces, which is realized by screwing the nozzle 4 in the nozzle holder 6.

The elimination of the indirect cooling for the nozzle 4 leads to a considerable simplification of the structure of the plasma cutting torch 1, since the coolant spaces of the nozzle holder 6, which are otherwise necessary to lead the coolant back and away, omitted. The cooling of the electrode takes place as in FIG. 1 ,

In the FIG. 3 For example, a plasma cutting torch 1 is shown in which a nozzle 4 is cooled indirectly via a nozzle holder 6, to which the coolant is led away again through a coolant chamber 6.10 (WV1) and via a coolant chamber 6.11 (WR1). The in the FIGS. 1 and 2 shown direct cooling of the electrode 2 is not provided. The heat conduction from the electrode 2 to the nozzle 4 via a trained as a plasma gas guide part 3 insulating part to the indirect coolant-cooled nozzle 4. In this regard, the comments on the FIGS. 1 and 2 ,

This leads to a considerable simplification of the structure of the plasma torch 1 and the electrode 2, since that in the FIGS. 1 and 2 shown cooling tube 10 and the coolant spaces 2.10 and 10.10 omitted, which are otherwise necessary to the cooling liquid back (WV2) and back away (WR2).

The Indian FIG. 4 shown plasma cutting torch 1 differs from that in the FIG. 1 shown plasma cutting torch in that the nozzle 4 is cooled directly with a coolant. For this purpose, the nozzle 4 is fixed by a nozzle cap 5. An internal thread 5.20 of the nozzle cap 5 is screwed to an external thread 6.21 of a nozzle holder 6. The outer surface of the nozzle 4 and a part of the nozzle holder 6 and the inner surface of the nozzle cap 5 form a coolant space 4.10, through which the coolant flowing through coolant chambers 6.10 and 6.11 of the nozzle holder 6 (WV1) and back (WR1).

Between the nozzle 4 and an electrode 2, an insulating member formed as a plasma gas guide member 3 is disposed. This achieves the same benefits as those associated with FIG. 1 are explained. The heat is transferred between the electrode 2 and the nozzle 4 from the warmer to the colder component through the heat well-conductive formed as a plasma gas guide part 3 insulating part. The plasma gas guide member 3 is in contact with the electrode 2 and the nozzle 4 by contact. Thus, caused by high temperature differences mechanical stresses in the plasma cutting torch 1 can be reduced.

An advantage over the in Fig. 1 shown plasma cutting torch is that the direct coolant-cooled nozzle 4 is better cooled than the indirectly cooled. Since the coolant flows in this arrangement into the vicinity of the nozzle tip and a nozzle bore 4.1, where the largest heating of the nozzle, the cooling effect is particularly large. The sealing of the coolant space is effected by circular rings between the nozzle cap 5 and the nozzle 4, the nozzle cap 5 and the nozzle holder 6 and the nozzle 4 and the nozzle holder. 6

The nozzle cap 5 is also formed by the coolant flowing through the coolant space 4.10, which is formed by the outer surface of the nozzle 4 and the inner surface of the nozzle cap 5, cooled. The heating of the nozzle cap 5 is mainly due to the radiation of the arc or the plasma jet and the heated workpiece.

However, the structure of the plasma cutting torch 1 is more complicated because in addition a nozzle cap 5 is needed. The coolant used here is preferably a liquid, in the simplest case water.

FIG. 5 shows a plasma cutting torch 1, the plasma cutting torch of FIG. 1 similar, in which, however, in addition to the nozzle 4, a nozzle cap 8 is arranged. Holes 4.1 of the nozzle 4 and 8.1 of the nozzle cap 8 lie on a center line M. The inner surfaces of the nozzle cap 8 and a nozzle cap holder 9 form with the outer surfaces of the nozzle 4 and the nozzle holder 6 spaces 8.10 and 9.10 through which a secondary gas SG flows. This secondary gas exits the bore of the nozzle cap 8.1 and envelops the plasma jet (not shown) and provides a defined atmosphere around it. In addition, the secondary gas SG protects the nozzle 4 and the nozzle guard 8 from arcs that may form between them and the workpiece. These are referred to as double arcs and can lead to damage of the nozzle 4. In particular, when piercing the workpiece, the nozzle 4 and the nozzle cap 8 are heavily loaded by hot molten high-spraying material. The secondary gas SG, whose volume flow during piercing can be increased compared to the value during cutting, keeps the high-spraying material away from the nozzle 4 and the nozzle protection cap 8 and thus protects against damage.

For the cooling of the electrode 2 and the nozzle 4 apply to the plasma cutting torch 1 according to FIG. 1 made statements. Basically, even with a plasma cutting torch 1 with secondary gas direct cooling only the electrode 2 - as in FIG. 2 shown, and the indirect cooling only the nozzle 4 - as in FIG. 3 shown - possible. The statements made for this also apply.

At the in FIG. 5 shown plasma cutting torch 1, the nozzle protection cap 8 must be cooled in addition to the electrode 2 and 4 nozzle. The heating of the nozzle cap 8 is effected in particular by the radiation of the arc or the plasma jet and the heated workpiece. Especially when piercing the workpiece, the nozzle protection cap 8 is thermally heavily loaded and heated by highly hot glowing material and must be cooled. Therefore, heat and highly electrically conductive materials, usually metals, such as silver, copper, aluminum, tin, zinc, iron, alloyed steel or a metallic alloy (eg brass), in which these metals individually or at least 50% in total are used.

The secondary gas SG first flows through the plasma cutting torch 1 before passing through a first space 9,10 formed by the inner surfaces of the nozzle guard holder 9 and the nozzle guard 8 and the outer surfaces of the nozzle holder 6 and the nozzle 4. The first space 9:10 is also bounded by an insulating part formed as a secondary gas guiding part 7, which is located between the nozzle 4 and the nozzle protecting cap 8. The secondary gas guide part 7 may be formed in several parts.

In the secondary gas guide part 7 are holes 7.1. But it may also be openings, grooves or recesses through which the secondary gas SG flows. By a corresponding arrangement of the bores 7.1, for example arranged radially with a radial offset and / or an inclination to the center line M, the secondary gas can be set in rotation. This serves to stabilize the arc or the plasma jet.

After passing through the secondary gas guide member 7, the secondary gas flows into an inner space 8.10, which is formed by the inner surface of the nozzle cap 8 and the outer surface of the nozzle 4, and then emerges from the bore 8.1 of the nozzle cap 8. When the arc or plasma jet is burning, the secondary gas strikes it and can influence it.

The nozzle cap 8 is usually cooled only by the secondary gas SG. The gas cooling has the disadvantage that it is not effective and the required gas flow rate is very high in order to achieve acceptable cooling or heat dissipation. Gas volume flows of 5,000 to 11,000 l / h are often necessary here. At the same time, the volume flow of the secondary gas must be selected so that the best cutting results are achieved. Too large volume flows, which are necessary for the cooling but often worsen the cutting result.

In addition, the high gas consumption caused by large volume flows is uneconomical. This is especially true when other gases than air, so for example. Argon, nitrogen, hydrogen, oxygen or helium are used.

These disadvantages are eliminated by using the insulating member formed as the secondary gas guide member 7. By using such an insulating part electrical insulation between the nozzle cap 8 and the nozzle 4 is achieved. The electrical insulation in combination with the secondary gas SG protects the nozzle 4 and the nozzle protection cap 8 from arcs that may form between them and the workpiece. These are referred to as double arcs and can lead to damage of the nozzle 4 or the nozzle cap 8.

At the same time heat is transferred between the nozzle cap 8 and the nozzle 4 from the warmer to the colder component, in this case from the nozzle cap 8 to the nozzle 4, on the heat well-conducting, designed as secondary gas guide member 7 insulating part. The secondary gas guide member 7 is in contact with the nozzle protection cap 8 and the nozzle 4 by contact. This is done in this embodiment via annular surfaces 8.2 of the nozzle cap 8 and 7.4 of the secondary gas guide member 7 and the annular surfaces 7.5 of the secondary gas guide member 7 and 4.4 of the nozzle 4. These are frictional connections, the nozzle cap 8 using the nozzle cap holder 9, with an internal thread 9.20 on an external thread 11.20 a receptacle 11 is screwed. So this is pressed up against the secondary gas guide member 7 and this against the nozzle 4.

In this way, the heat from the nozzle cap 8 is directed towards the nozzle 4 and cooled it. The nozzle 4 in turn, as in the description of FIG. 1 explained, indirectly cooled.

Fig. 6 shows the structure of a plasma cutting torch 1 as in Fig. 4 in which, however, a nozzle protection cap 8 is additionally arranged outside the nozzle cap 5.

Holes 4.1 of the nozzle 4 and 8.1 of the nozzle cap 8 lie on a center line M. The inner surfaces of the nozzle cap 8 and the nozzle protection cap holder 9 form with the outer surfaces of the nozzle cap 5 and the nozzle 4 spaces 8.10 and 9.10, through which a secondary gas SG can flow. The secondary gas exits from the bore 8.1 of the nozzle cap 8, surrounds the plasma jet (not shown) and provides for a defined atmosphere around selbigen. In addition, the secondary gas SG protects the nozzle 4, nozzle cap 5 and the nozzle cap 8 from arcs that may form between them and a workpiece (not shown). These are referred to as double arcs and can damage the nozzle 4, the nozzle cap 5 and the nozzle cap 8 lead. In particular, when piercing a workpiece, the nozzle 4, the nozzle cap 5 and the nozzle cap 8 are heavily loaded by hot high-spraying material. The secondary gas SG, whose volume flow during piercing can be increased in relation to the value during cutting, keeps the highly spraying material away from the nozzle 4, the nozzle cap 5 and the nozzle protection cap 8, thus protecting against damage.

For the cooling of the electrode 2, the nozzle 4 and the nozzle cap 5 in the description of the Fig. 4 made statements.

The heating of the nozzle cap 8 is effected in particular by the radiation of the arc or the plasma jet and the heated workpiece. Especially when piercing the workpiece, the nozzle protection cap 8 is thermally heavily loaded and heated by highly hot glowing material and must be cooled. Therefore, for good heat and good electrical conductivity materials, usually metals, for example copper, aluminum, tin, zinc, iron or alloys, in which at least one of these metals is included, used.

The secondary gas SG first flows through the plasma torch 1 before passing through a space 9.10 formed by the inner surfaces of the nozzle guard holder 9 and the nozzle guard 8 and the outer surfaces of a nozzle holder 6 and the nozzle cap 5. The space 9.10 is also bounded by an insulating part formed as a secondary gas guiding part 7 for the secondary gas SG, which is located between the nozzle cap 5 and the nozzle protecting cap 8.

In the secondary gas guide part 7 are holes 7.1. But it may also be openings, grooves or recesses through which the secondary gas SG flows. By a corresponding arrangement of these, for example, a radial offset having and / or radially inclined with an inclination to the center line M holes 7.1, the secondary gas SG can be set in rotation. This serves to stabilize the arc or the plasma jet.

After passing through the secondary gas guide member 7, the secondary gas SG flows into the space (inner space) 8.10 formed by the inner surface of the nozzle guard 8 and the outer surface of the nozzle cap 5 and the nozzle 4, and then exits from the bore 8.1 of the nozzle guard 8. When the arc or plasma jet is burning, the secondary gas SG strikes it and can influence it.

The nozzle cap 8 is usually cooled only by the secondary gas SG. The gas cooling has the disadvantage that it is not effective and the required gas flow rate is very high in order to achieve acceptable cooling or heat dissipation. Gas volume flows of 5,000 to 11,000 l / h are often necessary here. At the same time, the volume flow of the secondary gas must be selected so that the best cutting results are achieved. Too large volume flows, which are necessary for the cooling but often worsen the cutting result. In addition, the high gas consumption caused by large volume flows is uneconomical. This is especially true when gases other than air, such as argon, nitrogen, hydrogen, oxygen or helium are used. These disadvantages are eliminated by the use of the formed as a secondary gas guide member 7 insulating part. By using such an insulating part, the electrical insulation between the nozzle cap 8 and the nozzle cap 5 and thus the nozzle 4 is achieved. The electrical insulation in combination with the secondary gas SG protects the nozzle 4, the nozzle cap 5 and the nozzle cap 8 from arcs that may form between them and a workpiece (not shown). These are called double-sided bends and may damage the nozzle, nozzle cap, and nozzle cap.

At the same time heat is transferred between the nozzle cap 8 and nozzle cap 5 from the warmer to the colder component, in this case from the nozzle cap 8 to the nozzle cap 5, on the heat well-conducting, designed as secondary gas guide member 7 insulating part. The secondary gas guide member 7 is in contact with the nozzle cap 8 and the nozzle cap 5 by contact. This is done in this embodiment by annular surfaces 8.2 of the nozzle cap 8 and 7.4 of the secondary gas guide member 7 and the annular surfaces 7.5 of the secondary gas guide member 7 and 5.3 of the nozzle cap 5. It is in this example to non-positive connections, the nozzle cap 8 using the Düsenschutzkappenhalterung. 9 is screwed with an internal thread 9.20 to an external thread 11.20 a receptacle 11. So this is pressed up against the secondary gas guide member 7 for the secondary gas SG and this against the nozzle cap 5. In this way, the heat from the nozzle cap 8 directed towards the nozzle cap 5 and cooled it. The nozzle cap 5 in turn, as in the description of Fig. 4 explained, cooled.

Fig. 7 shows a plasma cutting torch 1, for which the embodiment according to the Fig. 6 statements made. In addition, the Düsenschutzkappenhalterung 9 is screwed with its internal thread 9.20 on the external thread 11.20 of the receptacle 11, which is designed as an insulating part. The receptacle 11 consists of an electrically non-conductive and heat-conducting material. Thus, heat from the nozzle cap holder 9, which may be obtained from, for example, the nozzle cap 8, a hot workpiece or the arc radiation, is transferred to the receptacle 11 via the internal thread 9.20 and the external thread 11.20. The receptacle 11 has coolant passages 11.10 and 11.11 for the coolant forward (WV1) and coolant return return (WR1), which are designed here as bores. Through this, the coolant flows and thus cools the receptacle 11. Thus, the cooling of the nozzle protection cap holder 9 is further improved. The heat is transferred from the nozzle protection cap 8 via its contact surface 8.3 designed as a circular ring surface onto a contact surface 9.1 likewise designed as an annular surface on the nozzle protection cap holder 9. The contact surfaces 8.3 and 9.1 touch in this example non-positively, wherein the nozzle cap 8 is screwed by means of nozzle protection cap holder 9 with the internal thread 9.20 on the external thread 11.20 of the receptacle 11. So this is pressed up against the secondary gas guide member 7 and the nozzle protection cap holder 9 against the nozzle cap 8. In the present example, the receptacle 11 is made of ceramic. Particularly suitable aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (about 10 ¹² Ω * cm).

Coolant is simultaneously guided through coolant chambers 6.10 and 6.11 of the nozzle holder 6 to the nozzle 4 and nozzle cap 5 and cools them.

Fig. 8 shows an embodiment of a plasma torch 1, that of the Fig. 7 similar. Thus, in principle also apply to the embodiments according to the Fig. 6 and 7 made statements. However, it contains another embodiment of the recording 11 designed as a nozzle cover holder 9 insulating part. The receptacle 11 consists in this example of two parts, wherein an outer part 11.1 of an electrically non-conductive and highly heat-conductive material and an inner part 11.2 consists of a good electrical conductivity and heat well conductive material.

The Düsenschutzkappenhalterung 9 is screwed with its internal thread 9.20 on the external thread 11.20 of the part 11.1 of the receptacle 11.

The electrically non-conductive and heat-conductive material is made of ceramic, for example aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity about 10 ¹² Ω ^* cm. The highly electrically conductive and highly conductive material is here a metal, for example copper, aluminum, tin, zinc, alloy steel or alloys (for example, brass), in which at least one of these metals is included.

In general, it is advantageous if the electrically highly conductive and highly heat-conducting material has a thermal conductivity of at least 40 W / (m * K) Ω and a specific electrical resistance of at most 0.01 Ω * cm. In particular, it may be provided that the electrically highly conductive and heat-conductive material has a thermal conductivity of at least 60 W / (m * K), better at least 90 W / (m * K) and preferably 120 W / (m * K) , More preferably, the good electrical conductivity and high thermal conductivity material has a thermal conductivity of at least 150 W / (m * K), more preferably at least 200 W / (m * K), and preferably at least 300 W / (m * K). Alternatively or additionally, it may be provided that the material which conducts electricity well and conducts heat well, a metal such as, for example, silver, copper, aluminum, tin, zinc, iron, alloyed steel or a metallic alloy (eg brass) in which these metals are contained individually or in total at least 50%.

The use of two different materials has the advantage that for the more complex part, in which different shapes are needed, for example, different holes, recesses, grooves, openings, etc., the material can be used, which can be processed easier and cheaper. In this embodiment, this is a metal that can be machined more easily than ceramics. Both parts (11.1 and 11.2) are frictionally connected to each other by touching each other touching, whereby a good heat transfer between the cylindrical contact surfaces 11.5 and 11.6 of the two parts 11.1 and 11.2 is achieved. The part 11.2 of the receptacle 11 has coolant passages 11.10 and 11.11 for the coolant supply (WV1) and coolant return (WR1), which are designed here as bores. Through this, the coolant flows and cools.

As reflected by the Fig. 8 and the associated description, the present invention also relates to an insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, wherein it consists of at least two parts, wherein one of the parts of an electrically non-conductive and heat well conductive material and the other or another of the parts of a good electrical conductivity and heat well conductive material.

FIG. 9 shows a further embodiment of a plasma cutting torch 1 according to the present invention, which in principle in the FIG. 8 similar embodiment shown. This also applies to those for the embodiments according to the FIGS. 6 . 7 and 8th made statements. However, there is shown another embodiment of the insulating member 11 designed as a receptacle 11 for the nozzle protection cap holder 9. The receptacle 11 consists of two parts, in which case the outer part 11.1 in contrast to in FIG. 8 shown Embodiment of a highly electrically conductive and highly heat-conductive material (for example, metal) and the inner part 11.2 of an electrically non-conductive and heat-conductive material (for example, ceramic) consists.

The Düsenschutzkappenhalterung 9 with its internal thread 9.20 is screwed to the external thread 11.20 of the part 11.1 of the receptacle 11.

In this embodiment, the advantage is that the external thread can be introduced into the metallic material used for the part 11.1 and not the more difficult to process ceramic.

The FIGS. 10 to 13 show (further) different embodiments of an insulating part designed as a plasma gas guide part 3 for the plasma gas PG, which in a plasma torch 1, as shown in the FIGS. 1 to 9 is shown, can be used, wherein the respective figure with the letter "a" shows a longitudinal section and the respective figure with the letter "b" shows a partially sectioned side view.

That in the Figures 10a and 10b shown plasma gas guide part 3 is made of an electrically non-conductive and heat well conductive material, here for example made of ceramic. Particularly suitable aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (about 10 ¹² Ω * cm). The associated advantages when used in a plasma cutting torch 1, such as better cooling, reduction of mechanical stresses, simpler structure, are already in the description of the above FIGS. 1 to 4 called and explained.

In the plasma gas guide part 3 there are radially arranged bores 3.1, which can be radially offset and / or radially inclined to the center line M, for example, and allow a plasma gas PG to rotate in the plasma cutting torch. When the plasma gas guide member 3 in the Plasma cutting torch 1 is installed, is its contact surface 3.6 (here, for example, cylindrical outer surface) with the contact surface 4.3 (here, for example, cylindrical inner surface) of the nozzle 4, their contact surface 3.5 (here, for example, cylindrical inner surface) with the contact surface 2.3 (here cylindrical, for example Outside surface) of the electrode 2 and its contact surface 3.7 (here, for example, annular surface) with the contact surface 4.5 (here, for example, annular surface) of the nozzle 4 by contact in contact ( FIGS. 1 to 9 ). In the contact surface 3.6 are grooves 3.8. These direct the plasma gas PG to the holes 3.1 before it is passed through them into an interior 4.2 of the nozzle 4, in which the electrode 2 is arranged.

The FIGS. 11a and 11b show a plasma gas guide part 3, which consists of two parts. A first part 3.2 consists of an electrically non-conductive and highly heat-conductive material, while a second part 3.3 consists of a good electrical conductivity and heat well conductive material.

For example, ceramic, again as an example aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (10 ¹² Ω * cm) is used here for the part 3.2 of the plasma gas-conducting part 3 , For the part 3.3 of the secondary gas guide part 3 here is a metal, such as silver, copper, aluminum, tin, zinc, iron, alloy steel or a metallic alloy (eg brass), in which these metals individually or in total at least 50% are used.

If, for example, copper is used for the part 3.3, the thermal conductivity of the plasma gas-conducting part 3 becomes greater than if it consisted only of electrically non-conductive and heat-conducting material, such as, for example, aluminum nitride. Depending on its purity, copper has a higher thermal conductivity (up to about 390 W / (m * K)) than aluminum nitride (about 180 W / (m * K)), which is currently considered one of the best heat sources conductive and at the same time not electrically well conductive material applies. Meanwhile, there is also aluminum nitride with a thermal conductivity of 220 W / (m * K).

This leads through the better thermal conductivity to an even better heat exchange between the nozzle 4 and the electrode 2 of the plasma cutting torch 1 according to the FIGS. 1 to 9 ,

In the simplest case, the parts 3.2 and 3.3 are connected by pushing over the contact surfaces 3.21 and 3.31.

The parts 3.2 and 3.3 can also be non-positively connected by the juxtaposed, facing and touching contact surfaces 3.20 with 3.30, 3.21 with 3.31 and 3.22 to 3.32. The contact surfaces 3.20, 3.21 and 3.22 are contact surfaces of the part 3.2 and the contact surfaces 3.30, 3.31 and 3.32 are contact surfaces of the part 3.3. The cylindrically shaped contact surfaces 3.31 (cylindrical outer surface of the part 3.3) and 3.21 (cylindrical inner surface of the part 3.2) form a non-positive connection by intermeshing. Here an interference fit DIN EN ISO 286 (for example H7 / n6, H7 / m6) is used between the cylindrical inner and outer surfaces.

It is also possible to connect both parts (3.2 and 3.3) by positive engagement, by soldering and / or by gluing and / or by a thermal process with each other.

Since the mechanical processing of the ceramic material is usually more difficult than that of a metal, the processing cost decreases. Here, for example, six holes 3.1 are introduced into the metallic part 3.3, which have a radial offset a1 and distributed at an angle α1 equidistantly on the circumference of the plasma gas guide. There are too Different shapes, such as grooves, recesses, holes, etc., easier to produce when they are introduced into the metal.

The FIGS. 12a and 12b show a plasma gas guide part 3, which consists of two parts, wherein a first part 3.2 made of an electrically non-conductive and heat-conductive material, while a second part 3.3 consists of an electrically non-conductive and non-heat conducting material.

For the part 3.2 of the plasma gas-conducting part 3, ceramic is used as an example, again as an example aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (about 10 ¹² Ω * cm) , used. For example, a plastic, for example PEEK, PTFE (polytetrafluoroethene), torlon, polyamide-imide (PAI), polyimide (PI), which has a high temperature resistance (at least 200 ° C.) and a high specific electrical resistance can be used for the part 3.3 of the plasma gas-conducting part 3 (at least 10 ⁶ , better at least 10 ¹⁰ Ω * cm) can be used.

In the simplest case, the parts 3.2 and 3.3 are connected by pushing together the contact surfaces 3.21 and 3.31. They can also be frictionally connected by 3.30, 3.21 to 3.31 and 3.22 to 3.32 through the pressed, opposite and touching contact surfaces 3.20. The cylindrically shaped contact surfaces 3.31 (cylindrical outer surface of the part 3.3) and 3.21 (cylindrical inner surface of the part 3.2) then form the frictional connection by intermeshing. Here an interference fit DIN EN ISO 286 (for example H7 / n6, H7 / m6) is used between the cylindrical inner and outer surfaces. It is also possible to connect both parts (3.2 and 3.3) by positive engagement and / or by gluing together.

Since the mechanical processing of the ceramic material is usually more difficult than that of a plastic, the processing cost decreases. For example, here are six holes 3.1 introduced into the plastic part 3.3, which have a radial offset a1 and distributed at an angle α1 equidistant on the circumference of the gas guide. There are also a variety of shapes, such as grooves, recesses, holes, etc. easier to produce when they are introduced into the plastic.

The FIGS. 13a and 13b show a plasma gas guide member 3 as shown in FIG FIG. 12 except that another part 3.4 made of a material having the same characteristics as part 3.3 belongs to the plasma gas guide part 3.

The parts 3.2 and 3.4 can be connected to each other as well as the parts 3.2 and 3.3, wherein the contact surfaces 3.23 are connected to 3.43, 3.24 to 3.44 and 3.25 to 3.25.

Since the mechanical processing of the ceramic material is usually more difficult than that of a plastic, the processing costs are reduced and are also a variety of shapes, such as recesses, holes, etc. easier to produce when they are introduced into the plastic.

The FIGS. 14a to 14b show a further embodiment of a plasma gas guide part 3. Die Figures 14c and 14d show a part 3.3 of the plasma gas guide part 3. The show FIGS. 14a and 14c a longitudinal section and the Figures 14b and 14d a partially sectioned side view.

A part 3.2 consists of an electrically non-conductive and highly heat-conductive material, while a part 3.3 consists of an electrically non-conductive and non-heat conducting material.

In part 3.3 of the plasma gas guide part 3 are radially arranged openings, here bores 3.1, which may be radially offset and / or radially inclined to the center line M and through which a plasma gas PG flows when the plasma gas guide member 3 is installed in the plasma cutting torch 1 (see FIGS. 1 to 9 ).

The part 3.3 has more radially arranged holes 3.9, which are larger than the holes 3.1. In these holes are six parts 3.2, which are exemplified here as a round pin introduced. These are equidistant at an angle that results between midpoint lines M3.9, distributed by α3 = 60 ° on the circumference.

When the plasma gas guide member 3 in the plasma cutting torch 1 after the FIGS. 1 to 9 is built contact surfaces are 3.61 (outer surfaces) of the parts 3.2 (round pins) with a contact surface 4.3 (here a cylindrical inner surface) of the nozzle 4 and contact surfaces 3.51 (inner surface) of the parts 3.2 (round pins) with the contact surface 2.3 (here a cylindrical outer surface) the electrode 2 by contact in contact.

The parts 3.2 have a diameter d3 and a length 13 which is at least as large as half the difference between the diameters d10 and d20 of the part 3.3. It is even better if the length 13 is slightly larger in order to obtain a secure contact between the contact surfaces of the round pins 3.2 and the nozzle 4 and the electrode 2. It is also advantageous if the surface of the contact surfaces 3.61 and 3.51 are not flat, but the cylindrical outer surface (contact surface 2.3) of the electrode 2 and the cylindrical inner surface (contact surface 4.3) of the nozzle 4 are adapted so that a positive connection is formed.

In the contact surface 3.6 are grooves 3.8. These direct the plasma gas PG to the holes 3.1 before it is passed through them into the interior 4.2 of the nozzle 4, in which the electrode 2 is arranged.

Since the mechanical processing of the ceramic material is usually more difficult than that of a plastic, the processing costs are reduced and are also a variety of shapes, such as grooves, recesses, holes, etc. easier to produce when they are introduced into the plastic. Thus, despite using the same round pins a variety of gas ducts can be produced inexpensively.

Furthermore, by changing the number or the diameter of the round pins 3.2 different thermal resistances and thermal conductivities of the plasma gas guide part 3 can be achieved.

If the diameter and / or the number of round pins is reduced, the thermal resistance increases and the thermal conductivity decreases.

Since, depending on the power to be converted in the plasma burner or plasma cutting torch from 500 W to 200 kW, very different thermal loads on the nozzles 4 and the electrode 2 occur, the adaptation of the thermal resistance is advantageous. For example, the manufacturing costs are reduced if fewer holes are introduced and less round pins must be used.

The FIGS. 15 to 17 show (further) different embodiments of a formed as a secondary gas guide member 7 for a secondary gas SG insulating part in a plasma cutting torch 1, as in the FIGS. 6 to 9 is shown, can be used, wherein the respective figure with the letter "a" is a partially sectioned plan view and the respective figure with the letter "b" shows a sectional side view.

The FIGS. 15a and 15b show a secondary gas guide part 7 for a secondary gas SG, as in a plasma cutting torch according to the FIGS. 6 to 9 can be used.

That in the FIGS. 15a and 15b shown secondary gas guide member 7 consists of an electrically non-conductive and heat well conductive material, here, for example, ceramic. Particularly suitable here is aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (about 10 ¹² Ω * cm). Due to the low thermal resistance or the high thermal conductivity high temperature differences can be avoided and thereby caused mechanical stresses in the plasma cutting torch can be reduced.

In the secondary gas guide member 7 are radially arranged holes 7.1, which can also radially or radially offset and / or radially inclined to the center line M and through which the secondary gas SG can flow or flows when the secondary gas guide member 7 is installed in the plasma cutting burner 1. In this example, 12 bores are offset radially by a dimension a11 and distributed equidistantly around the circumference, the angle enclosed by the centers of the bores being denoted by α11. But it may also be openings, grooves or recesses through which the secondary gas SG flows when the secondary gas guide member 7 is installed in the plasma cutting burner 1. The secondary gas guide part 7 has two annular contact surfaces 7.4 and 7.5.

By using this secondary gas guide member 7, the electrical insulation between the nozzle cap 8 and the nozzle cap 5 and thus the nozzle 4 of the in the FIGS. 6 to 9 achieved plasma cutting torch 1 achieved. The electrical insulation in combination with the secondary gas protects the nozzle 4, the nozzle cap 5 and the nozzle cap 8 from arcs that may form between them and the workpiece (not shown). These are referred to as double arcs and can damage the nozzle 4, the nozzle cap 5 and the nozzle cap 8 lead.

At the same time heat between the nozzle cap 8 and the nozzle cap 5 from the warmer to the colder component out, in this case from the nozzle cap 8 to the nozzle cap 5, on the heat well-conductive, designed as secondary gas guide member 7 Transfer insulating part. The secondary gas guide member 7 is in contact with the nozzle cap 8 and the nozzle cap 5 by contact. This is done in this embodiment by annular surfaces 8.2 of the nozzle cap 8 and 7.4 of the secondary gas guide member 7 and annular surfaces 7.5 of the secondary gas guide member 7 and 5.3 of the nozzle cap 5, which, as in the FIGS. 6 to 9 shown, touch.

The FIGS. 16a and 16b also show a secondary gas guide part 7 for a secondary gas SG, which consists of two parts. A first part 7.2 consists of an electrically non-conductive and highly heat-conductive material, while a second part 7.3 consists of a good electrical conductivity and heat well conductive material.

For example, for the part 7.2 of the secondary gas guide part 7, ceramic as an example is again aluminum nitride, which has a very good thermal conductivity (about 180 W / (m * K)) and a high electrical resistivity (about 10 ¹² Ω * cm), used. For the part 7.3 of the secondary gas guide part 7 here is a metal, such as silver, copper, aluminum, tin, zinc, iron, alloyed steel or a metallic alloy (eg brass), in which these metals individually or in total at least 50% are used.

If, for example, copper is used for the part 7.3, the thermal conductivity of the secondary gas guide part 7 becomes greater than if this consisted only of electrically non-conductive and heat-conducting material, such as aluminum nitride. Depending on its purity, copper has a higher thermal conductivity (up to about 390 W / (m * K)) than aluminum nitride (about 180 W / (m * K)), which is currently one of the best heat-conducting and non-electric ones good conductive materials applies. This leads through the better conductivity to an even better heat exchange between the nozzle cap 8 and the nozzle cap 5 of the plasma cutting burner 1 of FIGS. 6 to 9 ,

In the simplest case, the parts are 7.2 and 7.3 connected by pushing the contact surfaces 7.21 and 7.31.

Parts 7.2 and 7.3 can also be frictionally connected to 7.30, 7.21 to 7.31 and 7.22 to 7.32 through the contact surfaces 7.20, which are pressed against one another and located opposite each other. The contact surfaces 7.20, 7.21 and 7.22 are contact surfaces of the part 7.2 and the contact surfaces 7.30, 7.31 and 7.32 are contact surfaces of the part 7.3. The cylindrically shaped contact surfaces 7.31 (cylindrical outer surface of the part 7.3) and 7.21 (cylindrical inner surface of the part 7.2) form by intermeshing a non-positive connection. Here an interference fit DIN EN ISO 286 (for example H7 / n6, H / m6) is used between the cylindrical inner and outer surfaces.

There is also the possibility to connect the two parts by positive engagement, by soldering and / or gluing together.

Since the mechanical processing of the ceramic material is usually more difficult than that of a metal, the processing cost decreases. Here, for example, twelve holes 7.1 are introduced in part 7.3 of metal, which have a radial offset a11 and distributed at an angle α11 equidistant on the circumference of the gas guide. There are also a variety of shapes, such as grooves, recesses, holes, etc. easier to produce when they are introduced into the metal.

The FIGS. 17a and 17b also show a secondary gas guide part 7 for a secondary gas SG, which consists of two parts. In contrast to the embodiment according to the FIG. 16 Here, a first part 7.2 consists of a good electrical conductivity and good thermal conductivity material and a second part 7.3 of an electrically non-conductive and heat-conductive material. Otherwise, the same comments apply as to the FIGS. 16a and 6b ,

In the Fig. 18a, 18b . 18c and 18d is another embodiment of a secondary gas guide member 7 for a secondary gas SG, which in a plasma cutting torch according to the Fig. 6 to 9 can be used shown.

The Fig. 18a shows a plan view and the Fig. 18b and 18c cut side views of different embodiments thereof. Fig. 18d shows a non-electrically conductive and heat non-conductive material existing part 7.3 of the secondary gas guide part 7th

In part 7.3 of the secondary gas guide part 7 are radially arranged holes 7.1, which can also be offset radially or radially and / or radially inclined to the center line M and through which the secondary gas SG can flow when the secondary gas guide member 7 is installed in the plasma cutting burner 1. In this example, twelve bores are offset radially by a dimension a11 and distributed equidistantly around the circumference, the angle enclosed by the centers of the bores being designated α11 (here for example 30 °). But it may also be openings, grooves or recesses through which the secondary gas SG flows when the secondary gas guide member 7 in the plasma cutting torch 1 (see, for example Fig. 6 to 9 ) is installed.

Fig. 18d shows that in this example, the part 7.3 has twelve more axially arranged holes 7.9, which are larger than the holes or openings 7.1.

In the Figs. 18a and 18b are in these holes 7.9 twelve parts 7.2, which are exemplified here as round pins introduced. The round pins 7.2 consist of an electrically non-conductive and heat well conductive material, while the part 7.3 consists of an electrically non-conductive and heat non-conductive material.

When the secondary gas guide member 7 in the plasma cutting torch 1 according to the Fig. 6 to 9 is installed, are contact surfaces 7.51 of the round pins 7.2 with a contact surface 5.3 (here, for example annular surface) of the nozzle cap 5 and contact surfaces 7.41 of the round pins 7.2 with a contact surface 8.2 (here, for example annular surface) of the nozzle cap by contact in contact ( Fig. 6 to 9 ).

The parts 7.2 have a diameter d7 and a length 17 which is at least as large as the width b of the part 7.3. It is even better if the length 17 is slightly larger in order to obtain a secure contact between the contact surfaces of the round pins 7.2 and the nozzle cap 5 and the nozzle cap 8.

The Fig. 18c shows another embodiment of the secondary gas guide member 7 for secondary gas. In this case, in each bore 7.9 two exemplified as round pin parts 7.2 and 7.6 are introduced. The part 7.3 consists of an electrically non-conductive and heat non-conductive material, the round pins 7.2 consist of an electrically non-conductive and heat well conductive material and the round pins 7.6 consist of a good electrical conductivity and heat well conductive material.

When the secondary gas guide member 7 in the plasma cutting torch 1 according to the Fig. 6 to 9 is installed, are contact surfaces 7.51 of the round pins 7.2 with a contact surface 5.3 (here, for example, the annular surface) of the nozzle cap 5 and contact surfaces 7.41 of the round pins 7.6 with a contact surface 8.2 (here, for example, the annular surface) of the nozzle cap 8 by touching in contact (see also Fig. 6 to 9 ). Both round pins 7.2 and 7.6 are connected by their contact surfaces 7.42 and 7.52 by touch.

The parts 7.2 have a diameter d7 and a length 171. The parts 7.6 have in this example the same diameter and a length 172, wherein the sum of the lengths 171 and 172 is at least as large as the width b of the part 7.3. It is even better if the sum of the lengths is slightly larger, for example greater than 0.1 mm to obtain a secure contact between the contact surfaces 7.51 of the round pins 7.2 and the nozzle cap 5 and the contact surfaces 7.41 of the round pins 7.6 and the nozzle cap 8.

As the Fig. 18c and the associated description, the present invention thus also relates in generalized form to an insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, the insulating part consisting of at least three parts, one of the parts made of an electrically non-conductive and heat-conductive material, another of the parts of an electrically non-conductive and non-heat conductive material and the other or another of the parts consists of a good electrical conductivity and heat well conductive material.

The in the 15 to 18 shown secondary gas guide parts 7 can also in a plasma cutting torch 1 according to Fig. 5 be used. There, the electrical insulation between the nozzle cap 8 and the nozzle 4 is realized by the use of this secondary gas guide part 7. The electrical insulation in combination with the secondary gas SG protects the nozzle 4 and the nozzle protection cap 8 from arcs that can form between them and a workpiece. These are referred to as double arcs and can lead to damage of the nozzle 4 and the nozzle cap 8.

At the same time, heat is transferred between the nozzle protection cap 8 and the nozzle 4 from the warmer to the colder component, in this case from the nozzle protection cap 8 to the nozzle 4, via the heat-conducting insulating member designed as secondary gas guide member 7. The secondary gas guide member 7 is in contact with the nozzle protection cap 8 and the nozzle 4 by contact. This is done for in the Fig. 15 . 16 and 17 shown embodiments of the secondary gas guide member 7 via the annular contact surfaces 8.2 of the nozzle cap 8 and the annular contact surfaces 7.4 of the secondary gas guide member 7 and the annular contact surfaces 7.5 of the secondary gas guide member 7 and the annular contact surfaces 4.4 of the nozzles 4, which, as in the Fig. 5 shown, touch.

In the embodiments of the in the Fig. 18b and 18c shown secondary gas guide member 7, the heat transfer via the annular contact surface 8.2 of the nozzle cap 8 and the contact surfaces 7.41 of the round pins 7.2 or 7.6 of Sekundärgasführungsteils 7 of 7.51 of the round pins 7.2 with the contact surface 4.4 (here, for example, the annular surface) of the nozzle 4 by touching, as in of the Fig. 5 shown.

The Fig. 19a to 19d show sectional views of arrangements of a nozzle 4 and a secondary gas guide member 7 for a secondary gas SG according to particular embodiments of the invention in the 15 to 18 , Here are the comments on Fig. 5 and to the 15 to 18 ,

It shows Fig. 19a an arrangement with a secondary gas guide part 7 according to Figs. 15a and 15b . Fig. 19b an arrangement with a secondary gas guide part according to the Fig. 16a and 16b . Fig. 19c an arrangement with a secondary gas guide part according to the Fig. 17a and 17b and Fig. 19d an arrangement with a secondary gas guide part according to Fig. 18a and Fig. 18b ,

In these embodiments, the secondary gas guide member 7 may be connected to the nozzle 4 in the simplest case by superimposing. But they can also be positively and non-positively connected or by gluing. When using metal / metal and / or metal / ceramic at the junction and soldering is possible as a connection.

The Fig. 20a to 20d show sectional views of arrangements of a nozzle cap 5 and a secondary gas guide member 7 for a secondary gas SG according to the 15 to 18 according to particular embodiments of the invention. Here are the comments on the Fig. 6 to 9 and to the 15 to 18 ,

It shows Fig. 20a an arrangement with a secondary gas guide part according to the Figs. 15a and 15b ; Fig. 20b an arrangement with a secondary gas guide part according to the Fig. 16a and 16b ; Fig. 20c an arrangement with a secondary gas guide part according to Fig. 17a and 17b and Fig. 20d an arrangement with a secondary gas guide part according to the Fig. 18a to 18d ,

In these embodiments, the secondary gas guide member 7 may be connected to the nozzle cap 5 in the simplest case by superimposing. But they can also be positively and non-positively connected or gluing. When using metal / metal and / or metal / ceramic at the junction and soldering is possible as a connection.

The Fig. 21a to 21d show sectional views of arrangements of a nozzle cap 8 and a secondary gas guide member 7 for a secondary gas SG according to the 15 to 18 , Here are the comments on the Fig. 5 to 9 and to the 15 to 18 ,

It shows Fig. 21a an arrangement with a secondary gas guide part according to the Figs. 15a and 15b ; Fig. 21b an arrangement with a secondary gas guide part according to the Fig. 16a and 16b ; Fig. 21c an arrangement with a secondary gas guide part according to the Fig. 17a and 17b and Fig. 21d an arrangement with a secondary gas guide part according to the Fig. 18a to 18d ,

In these embodiments, the secondary gas guide member 7 may be connected to the nozzle protection cap 8 in the simplest case by superimposing. she but can also be positively and non-positively connected or gluing. When using metal / metal and / or metal / ceramic at the junction and soldering is possible as a connection.

The Figs. 22a and 22b show arrangements of an electrode 2 and a plasma gas guide part 3 for a plasma gas PG according to the Fig. 11 to 13 according to particular embodiments of the invention.

It shows Fig. 22a an arrangement with a plasma gas guide part according to Fig. 11a and Fig. 11b as well as the Fig. 22b an arrangement with a plasma gas guide part according to Fig. 13a and Fig. 13b ,

In this embodiment, a contact surface 2.3, for example, a cylindrical outer surface of the electrode 2 and a contact surface 3.5 a cylindrical inner surface of the plasma gas guide part 3. Preferably here is a clearance with little play, for example H7 / h6 according to DIN EN ISO 286 between the cylindrical inner and Used on the one hand to nesting and on the other hand a good contact and thus low thermal resistance and thus good heat transfer. The heat transfer can be improved by applying thermal paste to these contact surfaces. Then a fit with a larger game, for example H7 / g6 can be used.

It is also possible to use an interference fit between the plasma gas guide part 3 and the electrode 2. Of course, this improves the heat transfer. This has the consequence that electrode 2 and plasma gas guide part 3 can only be replaced together in the plasma cutting torch 1.

The Fig. 23 shows an arrangement of an electrode 2 and a plasma gas guide part 3 for a plasma gas PG according to a particular embodiment of the present invention.

In this arrangement, contact surfaces are 3.51 of the round pins 3.2 of the plasma gas guide part 3 with a contact surface 2.3 (here, for example, cylindrical outer surface) of the electrode 2 by contact in contact (see also Fig. 1 to 9 ).

The parts 3.2 have a diameter d3 and a length 13 which is at least equal to half the difference between the diameters d10 and d20 of the part 3.3. It is even better if the length 13 is slightly larger in order to obtain a secure contact between the contact surfaces of the round pins 3.2 and the nozzle 4 and the electrode 2. It is advantageous, furthermore, if the surface of the contact surfaces 3.61 and 3.51 not just, but the cylindrical outer surface (contact surface 2.3) of the electrode 2 and the cylindrical inner surface (contact surface 4.3) of the nozzle are adapted so that a positive connection is formed.

The arrangements of wearing parts and the insulating part or the gas guide part are enumerated by way of example only. Of course, other combinations, such as nozzle and gas guide part possible.

When reference has been made in the foregoing description to cooling liquid or the like, it is intended to mean a cooling medium in general terms.

In the foregoing description, arrangements and complete plasma torches are described, inter alia. It will be understood by those skilled in the art that the invention may be embodied in sub-combinations and parts, such as components or wearing parts. Therefore, protection is explicitly claimed for it.

Finally, a few definitions that should apply to the entire preceding description:

"Electrically good conducting" should mean that the specific electrical resistance is not more than 0.01 Ω * cm.

"Electrically non-conductive" shall mean that the specific resistance is at least 10 ⁶ Ω * cm, better at least 10 ¹⁰ Ω * cm and / or that the voltage breakdown strength is at least 7 kV / mm, better at least 10 kV / mm.

"Heat well conductive" should mean that the thermal conductivity is at least 40 W / (m * K), better at least 60 W / (m * K), even better at least 90 W / (m * K).

"Heat well conductive" should mean that the thermal conductivity is at least 120 W / (m * K), better at least 150 W / (m * K), even better at least 180 W / (m * K).

Finally, "heat well conductive", in particular for metals, means that the thermal conductivity is at least 200 W / (m * K), better at least 300 W / (m * K).

The features of the invention disclosed in the foregoing description, in the drawing and in the claims may be essential both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

1

Plasma Welding Torches

2

electrode

2.1

electrode holder

2.2

emission insert

2.3

contact area

2.10

Coolant space

3

Plasma gas guiding part

3.1

drilling

3.2

part

3.3

part

3.4

part

3.5

contact area

3.6

contact area

3.7

contact area

3.8

groove

3.9

drilling

3.20

contact area

3.21

contact area

3.22

contact area

3.23

contact area

3.24

contact area

3.25

contact area

3.30

contact area

3.31

contact area

3:32

contact area

3:43

contact area

3:44

contact area

3:45

contact area

3:51

contact area

3.61

contact area

4

jet

4.1

nozzle bore

4.2

inner space

4.3

contact area

4.4

contact area

4.5

contact area

4.10

Coolant space

4.20

external thread

5

nozzle cap

5.1

Nozzle cap hole

5.3

contact area

5.20

inner thread

6

nozzle holder

6.10

Coolant space

6.11

Coolant space

6.20

inner thread

6.21

external thread

7

Secondary gas guide part

7.1

drilling

7.2

part

7.3

part

7.4

contact area

7.5

contact area

7.6

part

7.9

drilling

7.20

contact area

7.21

contact area

7.22

contact area

7.30

contact area

7.31

contact area

7:32

contact area

7:41

contact area

7:42

contact area

7:51

contact area

7:52

contact area

8th

Nozzle cap

8.1

Nozzle cap hole

8.2

contact area

8.3

contact area

8.10

inner space

8.11

inner space

9

Nozzle protection cap holder

9.1

contact area

9.10

inner space

9.20

inner thread

10

cooling pipe

10.1

Coolant space

11

admission

11.1

part

11.2

part

11.5

contact area

11.6

contact area

11:10

Coolant passage

11:11

Coolant passage

11:20

external thread

PG

plasma gas

SG

secondary gas

WR1

Coolant return 1

WR2

Coolant return 2

WV1

Coolant supply 1

WV2

Coolant flow 2

a1

radial offset

a11

radial offset

b

width

d3

diameter

d7

diameter

d10

outer diameter

d11

Inner diameter

d15

diameter

d20

Inner diameter

d21

outer diameter

d25

diameter

d30

Inner diameter

d31

outer diameter

d60

outer diameter

13

length

131

length

132

length

17

length

171

length

172

length

173

length

12

length

M

center line

M3.1

center line

M3.2

center line

M3.9

center line

M7.1

center line

M3.6

center line

α1

angle

α3

angle

α7

angle

α11

angle

Claims (25)

One or more parts insulating part for a plasma torch, in particular a plasma cutting torch, for electrical insulation between at least two electrically conductive components of the plasma torch, characterized in that
it consists of an electrically non-conductive and heat-conductive material or at least a part (3.2; 7.2; 11.1) thereof consists of an electrically non-conductive and heat-conductive material. Insulating part according to claim 1, characterized in that it consists of at least two parts (3.2, 3.3; 7.2, 7.3; 11.1, 11.2), one of the parts (3.2; 7.2; 11.1) being made of an electrically non-conductive and heat-conducting material and the other or at least one other of the parts (3.3, 7.3, 11.2) is made of an electrically non-conductive and non-heat conductive material. Insulating part according to claim 2, characterized in that the part (3.2) made of an electrically non-conductive and highly heat-conducting material has at least one surface acting as a contact surface (3.51, 3.61, 7.41, 7.51) which is in contact with an immediately adjacent surface of the part (3). 3.3, 7.3) is made of an electrically non-conductive and heat non-conductive material or protrudes beyond this. Insulating part according to claim 1, characterized in that it consists of at least two parts (3.2, 3.3, 7.2, 7.3), one of the parts (3.3, 7.3) being made of an electrically highly conductive and highly heat-conductive material and the other (3.2; 7.2) or at least one other of the parts consists of an electrically non-conductive and heat-conductive material. An insulating part according to claim 1, characterized in that it consists of at least three parts (7.2, 7.3, 7.6), wherein one of the parts (7.6) of a good electrical conductivity and good thermal conductivity material, another of the parts (7.2) of a electrically non-conductive and heat well conductive material and another of the parts (7.3) consists of an electrically non-conductive and heat non-conductive material. Insulating part according to one of the preceding claims, characterized in that the electrically non-conductive and heat-conducting material has a thermal conductivity of at least 40 W / (m * K), preferably at least 60 W / (m * K) and more preferably at least 90 W / (m * K), more preferably at least 120 W / (m * K), even more preferably at least 150 W / (m * K) and even more preferably at least 180W / (m * K). Insulating part according to one of the preceding claims, characterized in that the electrically non-conductive and heat-conductive material and / or the electrically non-conductive and non-conductive material has a specific electrical resistance of at least 10 ⁶ Ω * cm, preferably at least 10 ¹⁰ Ω * cm, and / or a voltage breakdown strength of at least 7 kV / mm, preferably at least 10 kV / mm. Insulating part according to one of the preceding claims, characterized in that the electrically non-conductive and heat-conducting material is a ceramic, preferably from the group of nitride ceramics, in particular the aluminum nitride, boron nitride and Silicon nitride ceramics, the carbide ceramics, in particular the silicon carbide ceramics, the oxide ceramics, in particular the alumina, zirconia and Berylliumoxidkeramiken, and the silicate ceramics is, or plastic, for example. Plastic Film is. Insulating part according to claim 2, or a claim directly or indirectly dependent thereon, characterized in that the electrically non-conductive and heat-non-conductive material has a thermal conductivity of at most 1 W / (m * K). Insulating part according to one of the preceding claims, characterized in that the parts form, force, cohesively and / or by gluing or by a thermal process, for. As soldering or welding, are connected together. Insulating part according to one of the preceding claims, characterized in that it has at least one opening and / or at least one recess and / or at least one groove (3.8), in particular wherein the at least one opening and / or the at least one recess and / or at least one groove in the electrically non-conductive and highly heat-conductive material and / or in the electrically non-conductive and non-heat conducting material and / or in the good electrical conductivity and heat well conductive material is / are. Insulating part according to one of the preceding claims, characterized in that it is designed to lead a gas, in particular a plasma, secondary or cooling gas. Arrangement comprising an electrode (2) and / or a nozzle (4) and / or a nozzle cap (5) and / or a nozzle cap (8) and / or a nozzle cap holder (9) for a plasma torch, in particular a plasma cutting torch (1), and an insulating member according to any one of the preceding claims. Arrangement according to claim 13, characterized in that the insulating part with the electrode (2) and / or the nozzle (4) and / or the nozzle cap (5) and / or the nozzle cap (8) and / or the nozzle cap holder (9) in direct contact. Arrangement comprising a receptacle (11) for a nozzle cap holder (9) and a nozzle cap holder (9) for a plasma torch, in particular a plasma cutting torch (1), characterized in that the receptacle (11) as a preferably with the nozzle cap holder (9) in direct Contact standing insulating part according to one of claims 1 to 12 is formed. Arrangement comprising an electrode (2) and a nozzle (4) for a plasma torch, in particular a plasma cutting torch (1), characterized in that between the electrode (2) and the nozzle (4) an insulating part designed as a plasma gas guide part (3) one of claims 1 to 12, preferably in direct contact with the same. Arrangement comprising a nozzle (4) and a nozzle cap (8) for a plasma torch, in particular a plasma cutting torch (1), characterized in that between the nozzle (4) and the nozzle cap (8) an insulating part designed as a secondary gas guide part (7) one of claims 1 to 12, preferably in direct contact with the same. Arrangement comprising a nozzle cap (5) and a nozzle cap (8) for a plasma torch, in particular a plasma cutting torch (1), characterized in that between the nozzle cap (5) and the nozzle cap (8) an insulating part designed as a secondary gas guide part (7) one of claims 1 to 12, preferably in direct contact with the same. Plasma torch, in particular plasma cutting torch (1), comprising at least one insulating part according to one of claims 1 to 12. Plasma torch according to claim 19, characterized in that the insulating part or an electrically non-conductive and heat well conductive material existing part of the same at least one surface acting as a contact surface, preferably two surfaces having at least one surface of a highly electrically conductive component, in particular an electrode (2), nozzle (4), nozzle cap (5), nozzle cap (8) or nozzle cap holder (9), the plasma torch is in direct contact. Plasma torch according to one of claims 19 to 20, characterized in that the insulating part is a gas guide part, in particular a plasma gas (3), secondary gas (7) or cooling gas guide part is. Plasma torch according to one of claims 19 to 21, characterized in that the insulating part has at least one surface which in operation has direct contact with a cooling medium, preferably a liquid and / or a gas and / or a liquid-gas mixture. Plasma torch, in particular plasma cutting torch (1), comprising at least one arrangement according to one of claims 13 to 18. Method for processing a workpiece with a thermal plasma or for plasma cutting or plasma welding, characterized in that a plasma torch according to any one of claims 19 to 23 is used. A method according to claim 24, characterized in that in the plasma torch in addition to the plasma jet, a laser beam of a laser is coupled, in particular wherein the laser is a fiber laser, diode laser and / or diode-pumped laser.

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