EP0208134B1 - Apparatus for cutting metallic work pieces by plasma - Google Patents

Apparatus for cutting metallic work pieces by plasma Download PDF

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Publication number
EP0208134B1
EP0208134B1 EP86107550A EP86107550A EP0208134B1 EP 0208134 B1 EP0208134 B1 EP 0208134B1 EP 86107550 A EP86107550 A EP 86107550A EP 86107550 A EP86107550 A EP 86107550A EP 0208134 B1 EP0208134 B1 EP 0208134B1
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EP
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Prior art keywords
gas
plasma
electrode
nozzle body
bore
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EP86107550A
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German (de)
French (fr)
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EP0208134A3 (en
EP0208134A2 (en
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Wilhelm Dinse
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/28—Cooling arrangements

Definitions

  • the invention relates to a device for plasma cutting of metallic workpieces with an electrode, which is surrounded by a nozzle body, forming a central space, which has the plasma bore, which is centrally surrounded by a number of fine bores in the nozzle body.
  • a device of the type mentioned is known.
  • This device has a central bore through which the plasma gas is supplied.
  • the electrode is arranged in this hole.
  • the plasma gas exits through a plasma bore in an annular body inserted in the front part of the housing.
  • a protective gas together with water is supplied through separate lines.
  • This protective gas-water mixture reaches a central or annular space which is formed by a nozzle body screwed into the front part together with the housing of the device.
  • the plasma bore is also located in this nozzle body. So there are two separate gas flows.
  • One gas stream is a plasma gas stream and the other is a protective gas stream.
  • the protective gas / water mixture emerges from the central area through the fine bores and meets the plasma stream emerging from the plasma bore.
  • a plasma jet i.e. an ionized gas stream
  • a plasma jet i.e. an ionized gas stream
  • the arc normally starts from a negatively polarized electrode, the cathode, in the gas flow.
  • the positive pole is either the nozzle itself or the metallic workpiece to be cut.
  • any gas can be converted to plasma by the high temperatures of an arc.
  • argon is used very often because the ionization voltage of this gas is low due to the high density.
  • argon is relatively expensive, so that also with other gases, e.g. with nitrogen or with air.
  • the plasma jet generates temperatures from 10 to over 20,000 ° C. This results in considerable thermal loads on the components of the plasma cutting device located in the vicinity of the plasma jet. These components, especially the plasma nozzle bore, must therefore be protected against excessive thermal loads.
  • the invention has for its object to provide a device of the type mentioned, which can be operated with only one gas to form the plasma gas and the cooling gas, preferably with nitrogen or air, and which is nevertheless cooled well, so that it with a long service life and can be operated reliably at high cutting temperatures.
  • This object is achieved by the design as a single-gas device, in which the plasma gas and cooling gas consist of the same gas that enters the central space, from which the gas portion forming the plasma flows through the centrally arranged plasma bore in the nozzle body, while the one serving for cooling Gas fraction flows through the fine bores also arranged in the nozzle body around the plasma bore.
  • This device is advantageously designed such that the only gas enters the central space through tangentially arranged bores and is thereby set into a twisting movement.
  • the device according to the invention works with only one gas, which, starting from the central space, is divided so that the essential part reaches the fine bores or slots and forms the cooling gas flow.
  • the passage of the gas through the fine bores or slots takes place with simultaneous expansion, so that not only a protective gas flow is formed here, but also intensive cooling takes place where the heat is generated, ie the heat does not change Components that are then cooled are transported away, but cooling takes place where the heat is generated, namely in the nozzle body.
  • the protective gas thus forms a protective shield against the heat radiation emanating from the workpiece, and the heat is removed by the expanding gas flow.
  • the cutting pistol shown in FIG. 1 consists of a pistol grip 1, a switch 2 and the pistol head 3.
  • the housing of the gun head is labeled 4.
  • the end of the housing is covered by a nozzle cap 5.
  • the housing 4 of the gun head 3 is shown essentially in section.
  • a feed line 6 for the cutting current leads into the housing and is hollow (at 7) for supplying the gas (e.g. nitrogen or compressed air).
  • a second feed line 8 transmits the ignition or pilot current.
  • the gas passes from the feed line 6 into the centrally formed feed line 12.
  • An insert 30 is screwed into this feed line 12.
  • a tube 31 which projects into a collecting space 32, specifically beyond the plane in which the radially and tangentially running bores 13 lie.
  • the end of this tube is designated 36.
  • a chamber 35 connects to the collecting space 32 and is closed at the bottom, i.e. has a floor.
  • This chamber 35 is formed in the electrode body 34, in which the electrode insert 39 made of a corresponding resistant material, such as e.g. Zircon.
  • This electrode insert 39 is designed as a thin and elongated rod which is exactly opposite the plasma opening 26.
  • the nozzle body 24 is provided with the fine bores or slots 27, which are arranged centrally around the plasma nozzle bore 26 and extend essentially axially.
  • the ignition space 37 surrounding the electrode body 34 is at its upper end, i.e. provided with a funnel-shaped extension 38 at the end remote from the plasma nozzle bore 26.
  • the gas supplied through lines 7 and 12 serves both as cooling gas and as plasma gas.
  • This gas flows bundled against the bottom of the chamber 35 in the electrode body 34 and then twisting through the tangential bores 13 into the central space 14 and partly through the extension 38 and the ignition chamber 37 to the plasma nozzle bore 26 against the workpiece and partly for the purpose cooling through the fine bores 27.
  • the compressed air is divided in such a way that the plasma gas flow is generated and maintained on the one hand, and that on the other hand sufficient air for cooling and protection passes through the fine bores or slots 27.
  • the nozzle body 24 When the device is to be put into operation, the nozzle body 24 is first briefly supplied with a relatively low current with a high voltage and a superimposed high frequency via an ignition device as a positive pole.
  • the plasma gas is ionized between the electrode 34 and the nozzle body 24 in the area of the ignition chamber 37, so that a pilot arc is ignited, which is immediately carried away by the plasma gas flow and blown into the open through the plasma nozzle bore 26.
  • a pilot arc strikes the plus-polarized workpiece, a much larger cutting current is automatically switched on and the ignition energy is switched off.
  • the cooling gas flow through the bores 27 in the nozzle body ensures appropriate cooling and shielding.
  • the safety shutdown 10 to which the electrical lines 11 lead, ensures an automatic interruption.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Arc Welding In General (AREA)
  • Plasma Technology (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

1. Apparatus for the plasa cutting of metallic workpieces with an electrode which, accompanied by the formation of a central area (14), is surrounded by a nozzle body (24), which has the plasma bore (26), which is centrally surrounded by a plurality of fine bores (27) in the nozzle body, characterized by the construction as a single-gas apparatus, in which the plasma gas and the cooling gas are constituted by the same gas, which enters the central area (14), from which the plasma-forming gas fraction flows through the centrally arranged plasma bore (26) in the nozzle body (24), whilst the gas fraction used for cooling purposes flows through the fine bores (27) located around the plasma bore (26) in nozzle body (24).

Description

Die Erfindung betrifft eine Vorrichtung zum Plasmaschneiden von metallischen Werkstücken mit einer Elektrode, die unter Bildung eines Mittelraumes von einem Düsenkörper umgeben ist, der die Plasmabohrung aufweist, die von einer Anzahl feiner Bohrungen in dem Düsenkörper zentrisch umgeben ist.The invention relates to a device for plasma cutting of metallic workpieces with an electrode, which is surrounded by a nozzle body, forming a central space, which has the plasma bore, which is centrally surrounded by a number of fine bores in the nozzle body.

Aus der US-A 3 567 898 ist eine Vorrichtung der eingangs genannten Art bekannt. Diese Vorrichtung weist eine zentrale Bohrung auf, durch die das Plasmagas zugeführt wird. In dieser Bohrung ist die Elektrode angeordnet. Das Plasmagas tritt durch eine Plasmabohrung in einem im vorderen Teil des Gehäuses eingesetzten Ringkörper aus. Durch getrennte Leitungen wird ein Schutzgas zusammen mit Wasser zugeführt. Dieses Schutzgas-Wasser-Gemisch gelangt in einen Mittel- oder Ringraum, der durch einen im vorderen Teil eingeschraubten Düsenkörper zusammen mit dem Gehäuse der Vorrichtung gebildet wird. In diesem Düsenkörper befindet sich auch die Plasmabohrung. Es sind also zwei getrennte Gasströme vorhanden. Bei dem einen Gasstrom handelt es sich um einen Plasmagasstrom und bei dem anderen um einen Schutzgasstrom. Aus dem Mittelraum tritt das Schutzgas-Wasser-Gemisch durch die feinen Bohrungen aus und trifft auf den aus der Plasmabohrung austretenden Plasmastrom.From US-A 3 567 898 a device of the type mentioned is known. This device has a central bore through which the plasma gas is supplied. The electrode is arranged in this hole. The plasma gas exits through a plasma bore in an annular body inserted in the front part of the housing. A protective gas together with water is supplied through separate lines. This protective gas-water mixture reaches a central or annular space which is formed by a nozzle body screwed into the front part together with the housing of the device. The plasma bore is also located in this nozzle body. So there are two separate gas flows. One gas stream is a plasma gas stream and the other is a protective gas stream. The protective gas / water mixture emerges from the central area through the fine bores and meets the plasma stream emerging from the plasma bore.

Aus der US-A 3 794 806 ist eine anders ausgebildete Vorrichtung bekannt, die ebenfalls mit zwei getrennten Gasen, einem Plasmagas und einem Schutzgas arbeitet. Beide Gase werden im Bereich des Düsenkörpers auf getrennten Wegen zum Austritt geführt. Die auch hier vorhandenen Bohrungen zum Durchtritt des Schutzgases sind nicht in dem Düsenkörper sondern in einem getrennten Bauteil ausgebildet. Hierdurch ist eine intensive Kühlung in diesem Bereich nicht möglich, so daß eine zusätzliche Wasserkühlung vorgesehen ist.From US-A 3 794 806 a differently designed device is known which also works with two separate gases, a plasma gas and a protective gas. Both gases are led to the outlet on separate paths in the area of the nozzle body. The bores also present here for the passage of the protective gas are not formed in the nozzle body but in a separate component. As a result, intensive cooling is not possible in this area, so that additional water cooling is provided.

Bei Plasmaschneidvorrichtungen wird ein Plasmastrahl, d.h. ein ionisierter Gasstrom, von sehr hoher Geschwindigkeit gebildet. Er entsteht, wenn man in einem Gasstrom, der durch eine Düse gepresst und auf diese Art beschleunigt wird, einen Lichtbogen zündet. Der Lichtbogen geht im Normalfall von einer im Gasstrom liegenden negativ gepolten Elektrode, der Kathode, aus. Der positive Pol ist entweder die Düse selbst oder das metallische Werkstück, das geschnitten werden soll.In plasma cutting devices, a plasma jet, i.e. an ionized gas stream, formed at a very high speed. It occurs when an arc is ignited in a gas stream that is pressed through a nozzle and accelerated in this way. The arc normally starts from a negatively polarized electrode, the cathode, in the gas flow. The positive pole is either the nozzle itself or the metallic workpiece to be cut.

Grundsätzlich kann jedes Gas durch hohe Temperaturen eines Lichtbogens zum Plasma umgewandelt werden. In der Praxis wird sehr häufig Argon verwendet, da die lonisationsspannung dieses Gases wegen der großen Dichte niedrig liegt. Argon ist aber verhältnismäßig teuer, so daß auch mit anderen Gasen, z.B. mit Stickstoff oder mit Luft, gearbeitet wird.In principle, any gas can be converted to plasma by the high temperatures of an arc. In practice, argon is used very often because the ionization voltage of this gas is low due to the high density. However, argon is relatively expensive, so that also with other gases, e.g. with nitrogen or with air.

Der Plasmastrahl erzeugt Temperaturen von 10 bis über 20 000°C. Hierdurch treten erhebliche thermische Belastungen der in der Nähe des Plasmastrahles liegenden Bauteile der Plasmaschneidvorrichtung auf. Diese Bauteile, insbesondere die Plasmadüsenbohrung, müssen daher vor zu hohen thermischen Belastungen geschützt werden.The plasma jet generates temperatures from 10 to over 20,000 ° C. This results in considerable thermal loads on the components of the plasma cutting device located in the vicinity of the plasma jet. These components, especially the plasma nozzle bore, must therefore be protected against excessive thermal loads.

Der Erfindung liegt nun die Aufgabe zugrunde, eine Vorrichtung der eingangs genannten Art zu schaffen, die mit nur einem Gas zur Bildung des Plasmagases und des Kühlgases, vorzugsweise mit Stickstoff oder Luft, betrieben werden kann, und die dennoch gut gekühlt wird, so daß sie mit langer Lebensdauer und zuverlässig bei hohen auftretenden Schneidtemperaturen betrieben werden kann.The invention has for its object to provide a device of the type mentioned, which can be operated with only one gas to form the plasma gas and the cooling gas, preferably with nitrogen or air, and which is nevertheless cooled well, so that it with a long service life and can be operated reliably at high cutting temperatures.

Diese Aufgabe wird durch die Ausbildung als Eingasvorrichtung gelöst, bei der das Plasmagas und Kühlgas aus dem gleichen Gas bestehen, das in den Mittelraum eintritt, aus dem der das Plasma bildende Gasanteil durch die mittig angeordnete Plasmabohrung in dem Düsenkörper strömt, während der der Kühlung dienende Gasanteil durch die ebenfalls in dem Düsenkörper um die Plasmabohrung herum angeordneten feinen Bohrungen strömt.This object is achieved by the design as a single-gas device, in which the plasma gas and cooling gas consist of the same gas that enters the central space, from which the gas portion forming the plasma flows through the centrally arranged plasma bore in the nozzle body, while the one serving for cooling Gas fraction flows through the fine bores also arranged in the nozzle body around the plasma bore.

In vorteilhafter Weise ist diese Vorrichtung so ausgebildet, daß das einzige Gas in den Mittelraum durch tangential angeordnete Bohrungen eintritt und dadurch in eine tordierende Bewegung versetzt wird.This device is advantageously designed such that the only gas enters the central space through tangentially arranged bores and is thereby set into a twisting movement.

Die Vorrichtung nach der Erfindung arbeitet mit nur einem Gas, das, ausgehend von dem Mittelraum, so aufgeteilt wird, daß der wesentliche Teil zu den feinen Bohrungen oder Schlitzen gelangt, und den Kühlgasstrom bildet. Der Durchtritt des Gases durch die feinen Bohrungen oder Schlitze erfolgt unter gleichzeitiger Expansion, so daß hier nicht nur ein Schutzgasstrom gebildet wird, sondern auch eine intensive Kühlung, und zwar dort erfolgt, wo die Wärme erzeugt wird, d.h., die Wärme wird nicht zu anderen Bauteilen, die dann gekühlt werden, abtransportiert, sondern es erfolgt dort eine Kühlung, wo die Wärme entsteht, nämlich in dem Düsenkörper. Das Schutzgas bildet also einmal ein Schutzschild gegen die vom Werkstück ausgehende Wärmestrahlung, zum anderen wird die Wärme durch den expandierenden Gasstrom abtransportiert. Durch die Verwendung eines einzigen Gases ist die Vorrichtung entsprechend wirtschaftlich herstellbar und einsetzbar.The device according to the invention works with only one gas, which, starting from the central space, is divided so that the essential part reaches the fine bores or slots and forms the cooling gas flow. The passage of the gas through the fine bores or slots takes place with simultaneous expansion, so that not only a protective gas flow is formed here, but also intensive cooling takes place where the heat is generated, ie the heat does not change Components that are then cooled are transported away, but cooling takes place where the heat is generated, namely in the nozzle body. The protective gas thus forms a protective shield against the heat radiation emanating from the workpiece, and the heat is removed by the expanding gas flow. By using a single gas, the device can be produced and used accordingly economically.

Wenn die tangential verlaufenden Bohrungen vorgesehen sind, entsteht ein Wirbelstrom für eine gleichmäßige Verteilung des Gases vor dem Eintritt in die Bohrungen in dem Düsenkörper und für einen tordierenden und damit stabilen, zum Schneiden besonders geeigneten Plasmastrahl.If the tangential bores are provided, an eddy current is created for a uniform distribution of the gas before entering the bores in the nozzle body and for a twisting and therefore stable plasma jet which is particularly suitable for cutting.

Weitere Ausgestaltungen sind Gegenstand der Ansprüche 3 bis 6.Further refinements are the subject of claims 3 to 6.

Im folgenden wird die Erfindung unter Hinweis auf die Zeichnung anhand eines Ausführungsbeispieles näher erläutert.The invention is explained in more detail below with reference to the drawing using an exemplary embodiment.

Es zeigt:

  • Fig. 1 eine Seitenansicht einer Ausführungsform nach der Erfindung, die als Schneidpistole ausgebildet ist;
  • Fig. 2 einen Schnitt durch den Pistolenkopf einer sog. Eingasausführung.
It shows:
  • Figure 1 is a side view of an embodiment according to the invention, which is designed as a cutting gun.
  • Fig. 2 shows a section through the gun head of a so-called single gas version.

Die in Fig. 1 dargestellte Schneidpistole besteht aus einem Pistolengriff 1, einem Schalter 2 und dem Pistolenkopf 3.The cutting pistol shown in FIG. 1 consists of a pistol grip 1, a switch 2 and the pistol head 3.

Das Gehäuse des Pistolenkopfes ist mit 4 bezeichnet. Das Ende des Gehäuses wird durch eine Düsenkappe 5 abgedeckt.The housing of the gun head is labeled 4. The end of the housing is covered by a nozzle cap 5.

In Fig. 2 ist das Gehäuse 4 des Pistolenkopfes 3 im wesentlichen geschnitten dargestellt. In das Gehäuse führt eine Zuleitung 6 für den Schneidstrom, die zur Zuführung des Gases (z.B. Stickstoff oder Preßluft) hohl (bei 7) ausgebildet ist. Eine zweite Zuleitung 8 überträgt den Zünd- oder Pilotstrom.2, the housing 4 of the gun head 3 is shown essentially in section. A feed line 6 for the cutting current leads into the housing and is hollow (at 7) for supplying the gas (e.g. nitrogen or compressed air). A second feed line 8 transmits the ignition or pilot current.

Das Gas gelangt aus der Zuleitung 6 in die zentrisch ausgebildete Zuleitung 12. In dieser Zuleitung 12 ist ein Einsatz 30 eingeschraubt.The gas passes from the feed line 6 into the centrally formed feed line 12. An insert 30 is screwed into this feed line 12.

In dem Einsatz 30 befindet sich ein Rohr 31, das in einen Sammelraum 32 hineinragt, und zwar über die Ebene hinaus, in der die radial und tangential verlaufenden Bohrungen 13 liegen. Das Ende dieses Rohres ist mit 36 bezeichnet.In the insert 30 there is a tube 31 which projects into a collecting space 32, specifically beyond the plane in which the radially and tangentially running bores 13 lie. The end of this tube is designated 36.

An den Sammelraum 32 schließt sich eine Kammer 35 an, die unten verschlossen ist, d.h. einen Boden aufweist. Diese Kammer 35 ist in dem Elektrodenkörper 34 ausgebildet, in dem sich auch der Elektrodeneinsatz 39 aus einem entsprechenden widerstandsfähigen Material, wie z.B. Zirkon, befindet.A chamber 35 connects to the collecting space 32 and is closed at the bottom, i.e. has a floor. This chamber 35 is formed in the electrode body 34, in which the electrode insert 39 made of a corresponding resistant material, such as e.g. Zircon.

Dieser Elektrodeneinsatz 39 ist als dünnes und langgestrecktes Stäbchen ausgebildet, das der Plasmaöffnung 26 genau gegenüberliegt.This electrode insert 39 is designed as a thin and elongated rod which is exactly opposite the plasma opening 26.

Der Düsenkörper 24 ist mit den feinen Bohrungen oder Schlitzen 27 versehen, die zentrisch um die Plasmadüsenbohrung 26 angeordnet sind und im wesentlichen axial verlaufen. Der Zündraum 37, der den Elektrodenkörper 34 umgibt, ist an seinem oberen Ende, d.h. an dem der Plasmadüsenbohrung 26 abgelegenen Ende, mit einer trichterförmigen Erweiterung 38 versehen.The nozzle body 24 is provided with the fine bores or slots 27, which are arranged centrally around the plasma nozzle bore 26 and extend essentially axially. The ignition space 37 surrounding the electrode body 34 is at its upper end, i.e. provided with a funnel-shaped extension 38 at the end remote from the plasma nozzle bore 26.

Das durch die Leitungen 7 und 12 zugeführte Gas dient gleichzeitig als Kühlgas und als Plasmagas. Dieses Gas strömt gebündelt gegen den Boden der Kammer 35 in dem Elektrodenkörper 34 und dann durch die tangentialen Bohrungen 13 tordierend in den Mittelraum 14 und zu einem Teil durch die Erweiterung 38 und den Zündraum 37 zur Plasmadüsenbohrung 26 gegen das Werkstück und zum anderen Teil zum Zwecke der Kühlung durch die feinen Bohrungen 27.The gas supplied through lines 7 and 12 serves both as cooling gas and as plasma gas. This gas flows bundled against the bottom of the chamber 35 in the electrode body 34 and then twisting through the tangential bores 13 into the central space 14 and partly through the extension 38 and the ignition chamber 37 to the plasma nozzle bore 26 against the workpiece and partly for the purpose cooling through the fine bores 27.

In dem Mittelraum wird die Pressluft so aufgeteilt, daß einerseits der Plasmagasstrom erzeugt und stabil aufrechterhalten wird, und daß andererseits ausreichend Luft zur Kühlung und zum Schutz durch die feinen Bohrungen oder Schlitze 27 hindurchtritt..In the central space, the compressed air is divided in such a way that the plasma gas flow is generated and maintained on the one hand, and that on the other hand sufficient air for cooling and protection passes through the fine bores or slots 27.

Wenn die Vorrichtung in Betrieb genommen werden soll, wird zuerst der Düsenkörper 24 kurzzeitig über ein Zündgerät als Pluspol mit einem relativ geringen Strom mit hoher Spannung und einer überlagerten Hochfrequenz versorgt. In das Plasmagas wird zwischen der Elektrode 34 und dem Düsenkörper 24 im Bereich des Zündraumes 37 ionisiert, so daß ein Pilotlichtbogen gezündet wird, der durch den Plasmagasstrom sofort mitgerissen und durch die Plasmadüsenbohrung 26 ins Freie geblasen wird. Wenn der Pilotlichtbogen auf das plusgepolte Werkstück auftrifft, wird automatisch ein sehr viel größerer Schneidstrom eingeschaltet und die Zündenergie abgeschaltet. Gleichzeitig sorgt der Kühlgasstrom durch die Bohrungen 27 im Düsenkörper für eine entsprechende Kühle und Abschirmung.When the device is to be put into operation, the nozzle body 24 is first briefly supplied with a relatively low current with a high voltage and a superimposed high frequency via an ignition device as a positive pole. The plasma gas is ionized between the electrode 34 and the nozzle body 24 in the area of the ignition chamber 37, so that a pilot arc is ignited, which is immediately carried away by the plasma gas flow and blown into the open through the plasma nozzle bore 26. When the pilot arc strikes the plus-polarized workpiece, a much larger cutting current is automatically switched on and the ignition energy is switched off. At the same time, the cooling gas flow through the bores 27 in the nozzle body ensures appropriate cooling and shielding.

Wenn die Düsenkappe 5 bei Stillstand zu Reparaturzwecken abgenommen werden sollte, und vergessen wurde, den Strom abzuschalten, so sorgt die Sicherheitsabschaltung 10, zu der elektrische Leitungen 11 führen, für eine automatische Unterbrechung.If the nozzle cap 5 should be removed for repair purposes when it is at a standstill and it has been forgotten to switch off the power, the safety shutdown 10, to which the electrical lines 11 lead, ensures an automatic interruption.

Claims (6)

1. Apparatus for the plasa cutting of metallic workpieces with an electrode which, accompanied by the formation of a central area 14, is surrounded by a nozzle body (24), which has the plasma bore (26), which is centrally surrounded by a plurality of fine bores (27) in the nozzle body, characterized by the construction as a single-gas apparatus, in which the plasma gas and the cooling gas are constituted by the same gas, which enters the central area (14), from which the plasma-forming gas fraction flows through the centrally arranged plasma bore (26) in the nozzle body (24), whilst the gas fraction used for cooling purposes flows through the fine bores (27) located around the plasma bore (26) in nozzle body (24).
2. Apparatus according to claim 1, characterized in that the only gas enters the central area (14) through tangentially positioned bores (13) and consequently a twisting movement is imparted to it.
3. Apparatus according to claims 1 or 2, characterized in that the end of line (12) for the sole gas is constructed to form a narrow nozzle (36), which leads into a chamber (35) closed in the flow direction in an electrode body (34) carrying electrode (39).
4. Apparatus according to claims 1, 2 or 3, characterized in that the electrode, as an electrode insert (39), is embedded in an electrode body (34) and is constructed as an elongated, thin, axially directed rod.
5. Apparatus according to claims 3 or 4, characterized in that the ignition area surrounding the electrode body (34) has at its end facing the central area (14) a funnel-shaped widened portion (38).
6. Apparatus according to one or more of the preceding claims, characterized in that a safety disconnect (10) is provided for the cutting current and comes into action on removing an ignition cap (5).
EP86107550A 1985-07-05 1986-06-03 Apparatus for cutting metallic work pieces by plasma Expired - Lifetime EP0208134B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86107550T ATE52151T1 (en) 1985-07-05 1986-06-03 DEVICE FOR PLASMA CUTTING OF METALLIC WORKPIECES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3524034 1985-07-05
DE19853524034 DE3524034A1 (en) 1985-07-05 1985-07-05 DEVICE FOR PLASMA CUTTING METAL WORKPIECES

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EP0208134A2 EP0208134A2 (en) 1987-01-14
EP0208134A3 EP0208134A3 (en) 1988-01-07
EP0208134B1 true EP0208134B1 (en) 1990-04-18

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JP (1) JPS629779A (en)
AT (1) ATE52151T1 (en)
DE (2) DE3524034A1 (en)

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US9560732B2 (en) 2006-09-13 2017-01-31 Hypertherm, Inc. High access consumables for a plasma arc cutting system

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US9662747B2 (en) 2006-09-13 2017-05-30 Hypertherm, Inc. Composite consumables for a plasma arc torch
US7989727B2 (en) 2006-09-13 2011-08-02 Hypertherm, Inc. High visibility plasma arc torch
US10194516B2 (en) 2006-09-13 2019-01-29 Hypertherm, Inc. High access consumables for a plasma arc cutting system
US10098217B2 (en) 2012-07-19 2018-10-09 Hypertherm, Inc. Composite consumables for a plasma arc torch

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US9560732B2 (en) 2006-09-13 2017-01-31 Hypertherm, Inc. High access consumables for a plasma arc cutting system

Also Published As

Publication number Publication date
JPS629779A (en) 1987-01-17
DE3524034A1 (en) 1987-01-08
EP0208134A3 (en) 1988-01-07
ATE52151T1 (en) 1990-05-15
EP0208134A2 (en) 1987-01-14
DE3670555D1 (en) 1990-05-23

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