EP0837621A1 - Plasma torch with new sealing features - Google Patents

Plasma torch with new sealing features Download PDF

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Publication number
EP0837621A1
EP0837621A1 EP97402414A EP97402414A EP0837621A1 EP 0837621 A1 EP0837621 A1 EP 0837621A1 EP 97402414 A EP97402414 A EP 97402414A EP 97402414 A EP97402414 A EP 97402414A EP 0837621 A1 EP0837621 A1 EP 0837621A1
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EP
European Patent Office
Prior art keywords
cathode
anode
plasma torch
plasma
capillary tube
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Granted
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EP97402414A
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German (de)
French (fr)
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EP0837621B1 (en
Inventor
Christian Gay
Emmanuel Mornay
Gilles Guillot
Patrice Fournier
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Giat Industries SA
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Giat Industries SA
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Publication of EP0837621A1 publication Critical patent/EP0837621A1/en
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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
    • H05H1/52—Generating plasma using exploding wires or spark gaps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41—WEAPONS
    • F41A—FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE
    • F41A19/00—Firing or trigger mechanisms; Cocking mechanisms
    • F41A19/58—Electric firing mechanisms
    • F41A19/63—Electric firing mechanisms having means for contactless transmission of electric energy, e.g. by induction, by sparking gap

Definitions

  • the technical field of the invention is that of torches plasma.
  • a plasma torch is a system that generates high pressure gases (around 500 MPa) from a high voltage electrical discharge (of the order of 20 kV) caused between two electrodes.
  • Plasma torches are used in industry for for example cutting conductive materials, or still to destroy certain products or materials, or to make metallic deposits. They are also used in the armaments field to generate a pressure allowing the firing of a projectile.
  • Known plasma torches include an anode and a cathode separated by a capillary tube made in one material which is both electrically insulating and susceptible to decompose to generate a plasma (for example a plastic material).
  • the electric discharge between anode and cathode is primed using a copper or other fuse conductive material. The electric arc thus created causes a plasma which ablates the wall of the capillary tube which leads to the generation of high pressure light gases and high temperature.
  • gases are used either to directly accelerate a projectile, either to vaporize a fluid (for example water) which increases the volume of gas.
  • anode and cathode are fixed on either side of a support tube which ensures the torch stiffness and radial confinement of the plasma generates.
  • the cathode is annular in order to allow an exit axial of the plasma jet through it.
  • the invention provides a plasma torch whose mechanical strength and tightness are improved.
  • the invention therefore relates to a plasma torch comprising an anode and a cathode separated by a tube capillary made of an electrical insulating material and ablatable by the action of plasma, torch characterized in that the anode has a conductive case closed at first end, case inside which the tube is placed capillary.
  • the tube capillary is separated from the anode by an insulating sheath.
  • the anode case extends longitudinally substantially to the cathode, the sheath insulator at least partially surrounding the cathode.
  • the cathode may have a conical bearing coming from position in a complementary conical housing of the case conductive, the insulating sheath having a flared part which is interposed between the conical bearing of the cathode and the conical housing of the conductive case.
  • the anode may include a base forming an arc foot disposed at the bottom of the conductive case.
  • the cathode may include a sealing lip ring applied against the insulating and delimiting sheath a bore receiving a reduced diameter end of the capillary.
  • the cathode may include an axial housing in which a conductive ring will be placed forming the arch foot.
  • the torch according to the invention may include a sleeve insulating tubing surrounding the anode and ensuring its secured to the cathode.
  • It may also include at least one O-ring disposed between the tubular sleeve and the insulating sheath.
  • This plasma torch 1 comprises an anode 2 and a cathode 3 separated by a capillary tube 4.
  • the torch 1 generally has a symmetry of revolution. It is installed in a bore 5 fitted on a support 6, which is here a weapon (not shown in detail), weapon which comprises a tube 7 and a breech plate 8.
  • the capillary 4 is made of an insulating material electric and susceptible to ablation, i.e. to generate light gases by the action of plasma.
  • a plastic material such as polyethylene. It has an axial bore 9 to inside which a fuse is positioned (not shown), for example a copper wire.
  • Anode 2 is constituted by a metal case which has a bottom 10 of reduced diameter and a body cylindrical 12.
  • the bottom 10 is intended to receive an electrical contact 11 which is mechanically integral with the cylinder head plate 8.
  • the cylindrical body 12 has an axial bore 13 to the interior of which houses the capillary 4 and a base 14 forming arc foot.
  • the base 14 is made of a very conductive material and with high mechanical strength which has the function of limiting erosion due to the foot of the electric arc.
  • It has a longitudinal channel 15 which makes it possible to evacuate the air trapped between the bottom 10 and the base 14 at the time of the installation of the latter, which makes it possible to apply the base 14 strongly against the bottom to ensure good contact electric.
  • the capillary tube 4 is separated from the anode 2 by a cylindrical sheath 19, which is made of a material electrical insulation, for example a fiber-based composite of glass.
  • This sheath is to provide insulation between the anode and the cathode.
  • the open end of anode 2 has a conical profile 16 which is complementary to a conical bearing 17 arranged on cathode 3. This conical profile facilitates mounting of the cathode and ensures the coaxiality of these two parts.
  • the insulating sheath 19 has a flared part 20 which is interposed between the conical bearing 17 of the cathode 3 and the conical housing 16 of the conductive case of anode 2 and avoids any electrical short circuit at this level between the anode and the cathode.
  • the cathode 3 has an annular sealing lip 18 which is applied against the insulating sheath 19 and which delimits a bore receiving an end 21 with diameter reduced capillary 4.
  • the lip 18 is intended to be deformed by the effect of the pressure of the plasma generated by the torch to prevent any plasma leak between the cathode 3 and the insulating sheath 19, leaks that would affect the efficiency of the torch and damage the electrical insulation.
  • the cathode 3 In order to locate the base of the electric arc, the cathode 3 also includes an axial housing 22 in which is disposed a conductive ring 23 forming the arc foot. This ring is made of the same material as the base 14.
  • the cathode 3 has an axial orifice 24 which makes communicate the interior of the torch with a chamber 25 intended to receive a projectile (not shown) and possibly a gas-generating material (for example the water).
  • a projectile not shown
  • a gas-generating material for example the water
  • the flared part 20 of the insulating sheath 19 ends in a cylindrical portion 26 which surrounds the cathode 3.
  • An insulating tubular sleeve 27 surrounds the anode 2 and secures it to cathode 3 by through radial screws 28.
  • the sleeve 27 completes the electrical insulation between the anode and cathode.
  • O-rings 29, 30, 31 are arranged between the sleeve 27 and the insulating sheath 19. They allow avoid the formation of an electric arc at the level of the games radial mounting.
  • the current supply at the cathode is ensured by a contact ring 34 which remains integral with the support 6 and which carries at least two longitudinal tabs flexible 35.
  • the sleeve 27 also includes an annular machining 32 which is intended to receive and guide a crown 33 secured to an insulating sheath 36 which surrounds the contact 11 and electrically isolates it from the cylinder head plate 8.
  • a difference in electrical potential of around 20 kilo volts is applied between anode 2 and cathode 3.
  • the electrical insulation is ensured by the sheath 36 surrounding the contact 11, the insulating sleeve 27, the seals O-rings 29, 30 and 31 and the insulating sleeve 19.
  • anode and cathode are only connected to each other by the fuse placed inside the capillary 4.
  • This fuse initiates an electric arc between anode and cathode, arc which is maintained and causes the ablation of the material of the capillary and the generation of a plasma that comes out of the torch 1 through the axial hole 24.
  • the anode 2 proposed by the invention makes it possible to avoid any plasma leakage towards the rear of the torch (towards the contact 11).
  • the cylindrical body 12 of the anode 2 surrounds the capillary 4 over its entire length. It ensures the maintenance radial of this one despite the strong pressures developed at inside the torch. This results in excellent hold mechanical torch with minimal radial bulk.
  • the torch according to the invention can be used in the armament field for firing high-speed projectiles significant (greater than 2000 m / s).

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Engineering & Computer Science (AREA)
  • Plasma Technology (AREA)

Abstract

A plasma torch (1) is claimed comprising an anode (2) and a cathode (3) separated by a capillary tube (4) made from a material that is an electrical insulator and can be ablated under the action of the plasma. The anode (2) incorporates a conducting cover (12) closed at one end (10), inside which the capillary tube (4) is arranged. The capillary tube (4) is separated from the anode (2) by an insulating sheath (19). The anode cover (12) extends essentially longitudinally to the cathode (3) and the insulating sheath (19) surrounds the cathode (3) at least partially. The cathode (3) incorporates a conical bearing (17) positioned in a complementary conical housing (16) in the conducting cover (12). The insulating sheath (19) incorporates a flared part (20) that is interposed between the conical bearing (17) of the cathode (3) and the conical housing (16) of the conducting cover (12). The anode (2) also incorporates a base (14) forming an arc foot arranged at the bottom of the conducting cover (12). The cathode also incorporates an annular airtight lip (18) that is applied against the insulating sheath (19) and which delimits a boring to receive one end (21) with reduced diameter of the capillary tube (4). The cathode (3) also includes an axial housing (22) in which a conducting ring (23) is arranged to form the arc foot. A tubular insulating sleeve (27) surrounds the anode (2) and assures its integration with the cathode (3) and at least one toric joint (29,30,31) is arranged between the tubular sleeve (27) and the insulating sheath (19).

Description

Le domaine technique de l'invention est celui des torches à plasma.The technical field of the invention is that of torches plasma.

Une torche à plasma est un système qui permet d'engendrer des gaz à haute pression (de l'ordre de 500 MPa) à partir d'une décharge électrique de haute tension (de l'ordre de 20 kV) provoquée entre deux électrodes.A plasma torch is a system that generates high pressure gases (around 500 MPa) from a high voltage electrical discharge (of the order of 20 kV) caused between two electrodes.

Les torches à plasma sont utilisées dans l'industrie pour réaliser par exemple la découpe de matériaux conducteurs, ou encore pour détruire certains produits ou matériels, ou pour effectuer des dépôts métalliques. Elles sont également utilisées dans le domaine de l'armement pour engendrer une pression permettant le tir d'un projectile.Plasma torches are used in industry for for example cutting conductive materials, or still to destroy certain products or materials, or to make metallic deposits. They are also used in the armaments field to generate a pressure allowing the firing of a projectile.

On pourra par exemple considérer le brevet US4895062 qui décrit une arme utilisant une torche à plasma.We could for example consider the patent US4895062 which describes a weapon using a plasma torch.

Les torches à plasma connues comprennent une anode et une cathode séparées par un tube capillaire réalisé en un matériau qui est à la fois isolant électrique et susceptible de se décomposer pour engendrer un plasma (par exemple une matière plastique). La décharge électrique entre anode et cathode est amorcée au moyen d'un fusible en cuivre ou autre matériau conducteur. L'arc électrique ainsi créé provoque un plasma qui réalise l'ablation de la paroi du tube capillaire ce qui entraíne la génération de gaz légers à haute pression et haute température.Known plasma torches include an anode and a cathode separated by a capillary tube made in one material which is both electrically insulating and susceptible to decompose to generate a plasma (for example a plastic material). The electric discharge between anode and cathode is primed using a copper or other fuse conductive material. The electric arc thus created causes a plasma which ablates the wall of the capillary tube which leads to the generation of high pressure light gases and high temperature.

Ces gaz sont utilisés soit pour accélérer directement un projectile, soit pour vaporiser un fluide (par exemple de l'eau) qui permet d'accroítre le volume de gaz.These gases are used either to directly accelerate a projectile, either to vaporize a fluid (for example water) which increases the volume of gas.

Dans les torches à plasma connues, anode et cathode sont fixées de part et d'autre d'un tube support qui assure la rigidité de la torche et le confinement radial du plasma engendré.In known plasma torches, anode and cathode are fixed on either side of a support tube which ensures the torch stiffness and radial confinement of the plasma generates.

La cathode est annulaire afin de permettre une sortie axiale du jet de plasma au travers de celle ci.The cathode is annular in order to allow an exit axial of the plasma jet through it.

Il en résulte lors du fonctionnement un niveau de pression au niveau de l'anode qui est bien supérieur à celui développé au niveau de la cathode.This results in operation during a pressure at the anode which is much higher than that developed at the cathode level.

Concrètement on a pu mesurer des pressions de l'ordre de 400 MPa au niveau de la cathode et de 600 MPa au niveau de l'anode.Concretely, we were able to measure pressures of the order of 400 MPa at the cathode and 600 MPa at the level of the anode.

Une telle différence de pression nuit à la tenue mécanique de la torche. Elle peut également provoquer une dégradation de l'étanchéité entre l'anode et le support pouvant conduire à l'émission au niveau de l'anode de jets de plasma dirigés vers l'extérieur de la torche.Such a difference in pressure harms the holding torch mechanics. It can also cause degradation of the seal between the anode and the support which can lead to the emission at the anode of jets of plasma directed outside the torch.

C'est le but de l'invention que de proposer une torche à plasma ne présentant pas de tels inconvénients.It is the object of the invention to propose a torch to plasma without such drawbacks.

Ainsi l'invention propose une torche à plasma dont la tenue mécanique et l'étanchéité sont améliorées.Thus the invention provides a plasma torch whose mechanical strength and tightness are improved.

L'invention a donc pour objet une torche à plasma comprenant une anode et une cathode séparées par un tube capillaire réalisé en un matériau isolant électrique et ablatable par l'action du plasma, torche caractérisée en ce que l'anode comporte un étui conducteur fermé à une première extrémité, étui à l'intérieur duquel est disposé le tube capillaire.The invention therefore relates to a plasma torch comprising an anode and a cathode separated by a tube capillary made of an electrical insulating material and ablatable by the action of plasma, torch characterized in that the anode has a conductive case closed at first end, case inside which the tube is placed capillary.

Selon une modalité particulière de réalisation, le tube capillaire est séparé de l'anode par un fourreau isolant.According to a particular embodiment, the tube capillary is separated from the anode by an insulating sheath.

Avantageusement, l'étui de l'anode s'étend longitudinalement sensiblement jusqu'à la cathode, le fourreau isolant entourant au moins partiellement la cathode.Advantageously, the anode case extends longitudinally substantially to the cathode, the sheath insulator at least partially surrounding the cathode.

La cathode pourra comporter une portée conique venant se positionner dans un logement complémentaire conique de l'étui conducteur, le fourreau isolant comportant une partie évasée qui est interposée entre la portée conique de la cathode et le logement conique de l'étui conducteur.The cathode may have a conical bearing coming from position in a complementary conical housing of the case conductive, the insulating sheath having a flared part which is interposed between the conical bearing of the cathode and the conical housing of the conductive case.

L'anode pourra comporter un culot formant pied d'arc disposé au fond de l'étui conducteur.The anode may include a base forming an arc foot disposed at the bottom of the conductive case.

La cathode pourra comporter une lèvre d'étanchéité annulaire appliquée contre le fourreau isolant et délimitant un alésage recevant une extrémité à diamètre réduit du capillaire.The cathode may include a sealing lip ring applied against the insulating and delimiting sheath a bore receiving a reduced diameter end of the capillary.

La cathode pourra comporter un logement axial dans lequel sera disposé un anneau conducteur formant pied d'arc.The cathode may include an axial housing in which a conductive ring will be placed forming the arch foot.

La torche selon l'invention pourra comporter un manchon tubulaire isolant entourant l'anode et assurant sa solidarisation avec la cathode. The torch according to the invention may include a sleeve insulating tubing surrounding the anode and ensuring its secured to the cathode.

Elle pourra également comporter au moins un joint torique disposé entre le manchon tubulaire et le fourreau isolant.It may also include at least one O-ring disposed between the tubular sleeve and the insulating sheath.

L'invention sera mieux comprise à la lecture de la description qui va suivre d'un mode particulier de réalisation, description faite en référence au dessin annexé qui représente en coupe longitudinale une torche à plasma selon l'invention.The invention will be better understood on reading the description which follows of a particular mode of realization, description made with reference to the attached drawing which represents in longitudinal section a plasma torch according to the invention.

Cette torche à plasma 1 comprend une anode 2 et une cathode 3 séparées par un tube capillaire 4.This plasma torch 1 comprises an anode 2 and a cathode 3 separated by a capillary tube 4.

La torche 1 présente globalement une symétrie de révolution. Elle est mise en place dans un alésage 5 aménagé sur un support 6, qui est ici une arme (non représentée en détail), arme qui comporte un tube 7 et une plaque de culasse 8.The torch 1 generally has a symmetry of revolution. It is installed in a bore 5 fitted on a support 6, which is here a weapon (not shown in detail), weapon which comprises a tube 7 and a breech plate 8.

Le capillaire 4 est réalisé en un matériau isolant électrique et susceptible de s'ablater, c'est à dire d'engendrer des gaz légers par l'action du plasma. On réalisera par exemple le capillaire en une matière plastique telle que le polyéthylène. Il comporte un alésage axial 9 à l'intérieur duquel est positionné un fusible (non représenté), par exemple un fil de cuivre.The capillary 4 is made of an insulating material electric and susceptible to ablation, i.e. to generate light gases by the action of plasma. We for example make the capillary from a plastic material such as polyethylene. It has an axial bore 9 to inside which a fuse is positioned (not shown), for example a copper wire.

L'anode 2 est constituée par un étui métallique qui comporte un fond 10 de diamètre réduit et un corps cylindrique 12.Anode 2 is constituted by a metal case which has a bottom 10 of reduced diameter and a body cylindrical 12.

Le fond 10 est destiné à recevoir un contact électrique 11 qui est solidaire mécaniquement de la plaque de culasse 8.The bottom 10 is intended to receive an electrical contact 11 which is mechanically integral with the cylinder head plate 8.

Le corps cylindrique 12 présente un alésage axial 13 à l'intérieur duquel se loge le capillaire 4 ainsi qu'un culot 14 formant pied d'arc.The cylindrical body 12 has an axial bore 13 to the interior of which houses the capillary 4 and a base 14 forming arc foot.

Le culot 14 est réalisé en un matériau très conducteur et à haute tenue mécanique qui a pour fonction de limiter l'érosion due au pied de l'arc électrique.The base 14 is made of a very conductive material and with high mechanical strength which has the function of limiting erosion due to the foot of the electric arc.

Il comporte un canal longitudinal 15 qui permet d'évacuer l'air emprisonné entre le fond 10 et le culot 14 au moment de la mise en place de ce dernier, ce qui permet d'appliquer le culot 14 fortement contre le fond pour assurer un bon contact électrique.It has a longitudinal channel 15 which makes it possible to evacuate the air trapped between the bottom 10 and the base 14 at the time of the installation of the latter, which makes it possible to apply the base 14 strongly against the bottom to ensure good contact electric.

Le tube capillaire 4 est séparé de l'anode 2 par un fourreau cylindrique 19, qui est réalisé en un matériau isolant électrique, par exemple un composite à base de fibres de verre.The capillary tube 4 is separated from the anode 2 by a cylindrical sheath 19, which is made of a material electrical insulation, for example a fiber-based composite of glass.

Ce fourreau a pour fonction d'assurer l'isolation électrique entre l'anode et la cathode.The purpose of this sheath is to provide insulation between the anode and the cathode.

L'extrémité ouverte de l'anode 2 a un profil conique 16 qui est complémentaire d'une portée conique 17 aménagée sur la cathode 3. Ce profil conique facilite le montage de la cathode et assure la coaxialité de ces deux pièces.The open end of anode 2 has a conical profile 16 which is complementary to a conical bearing 17 arranged on cathode 3. This conical profile facilitates mounting of the cathode and ensures the coaxiality of these two parts.

Le fourreau isolant 19 comporte une partie évasée 20 qui s'interpose entre la portée conique 17 de la cathode 3 et le logement conique 16 de l'étui conducteur de l'anode 2 et évite tout court-circuit électrique à ce niveau entre l'anode et la cathode.The insulating sheath 19 has a flared part 20 which is interposed between the conical bearing 17 of the cathode 3 and the conical housing 16 of the conductive case of anode 2 and avoids any electrical short circuit at this level between the anode and the cathode.

La cathode 3 comporte une lèvre d'étanchéité annulaire 18 qui est appliquée contre le fourreau isolant 19 et qui délimite un alésage recevant une extrémité 21 à diamètre réduit du capillaire 4.The cathode 3 has an annular sealing lip 18 which is applied against the insulating sheath 19 and which delimits a bore receiving an end 21 with diameter reduced capillary 4.

La lèvre 18 est destinée à se déformer par l'effet de la pression du plasma engendré par la torche pour empêcher toute fuite de plasma entre la cathode 3 et le fourreau isolant 19, fuites qui nuiraient à l'efficacité de la torche et détérioreraient l'isolation électrique.The lip 18 is intended to be deformed by the effect of the pressure of the plasma generated by the torch to prevent any plasma leak between the cathode 3 and the insulating sheath 19, leaks that would affect the efficiency of the torch and damage the electrical insulation.

Afin de localiser le pied de l'arc électrique, la cathode 3 comporte également un logement axial 22 dans lequel est disposé un anneau conducteur 23 formant pied d'arc. Cet anneau est réalisé dans le même matériau que le culot 14.In order to locate the base of the electric arc, the cathode 3 also includes an axial housing 22 in which is disposed a conductive ring 23 forming the arc foot. This ring is made of the same material as the base 14.

La cathode 3 présente un orifice axial 24 qui fait communiquer l'intérieur de la torche avec une chambre 25 destinée à recevoir un projectile (non représenté) et éventuellement un matériau générateur de gaz (par exemple de l'eau).The cathode 3 has an axial orifice 24 which makes communicate the interior of the torch with a chamber 25 intended to receive a projectile (not shown) and possibly a gas-generating material (for example the water).

La partie évasée 20 du fourreau isolant 19 se termine par une portion cylindrique 26 qui entoure la cathode 3.The flared part 20 of the insulating sheath 19 ends in a cylindrical portion 26 which surrounds the cathode 3.

Un manchon tubulaire isolant 27 entoure l'anode 2 et assure sa solidarisation avec la cathode 3 par l'intermédiaire de vis radiales 28.An insulating tubular sleeve 27 surrounds the anode 2 and secures it to cathode 3 by through radial screws 28.

Le manchon 27 complète l'isolation électrique entre anode et cathode. Des joints toriques 29, 30, 31 sont disposés entre le manchon 27 et le fourreau isolant 19. Ils permettent d'éviter la formation d'un arc électrique au niveau des jeux de montage radiaux.The sleeve 27 completes the electrical insulation between the anode and cathode. O-rings 29, 30, 31 are arranged between the sleeve 27 and the insulating sheath 19. They allow avoid the formation of an electric arc at the level of the games radial mounting.

L'amenée de courant au niveau de la cathode est assurée par une bague de contact 34 qui reste solidaire du support 6 et qui porte au moins deux languettes longitudinales flexibles 35.The current supply at the cathode is ensured by a contact ring 34 which remains integral with the support 6 and which carries at least two longitudinal tabs flexible 35.

Ces dernières assurent un bon contact électrique malgré la présence d'un jeu radial entre cathode 3 et support 6, jeu destiné à faciliter la mise en place et le remplacement de la torche 1.These ensure good electrical contact despite the presence of a radial clearance between cathode 3 and support 6, clearance intended to facilitate the installation and replacement of the torch 1.

Le manchon 27 comporte également un usinage annulaire 32 qui est destiné à recevoir et guider une couronne 33 solidaire d'une gaine isolante 36 qui entoure le contact 11 et l'isole électriquement de la plaque de culasse 8.The sleeve 27 also includes an annular machining 32 which is intended to receive and guide a crown 33 secured to an insulating sheath 36 which surrounds the contact 11 and electrically isolates it from the cylinder head plate 8.

Cette disposition particulière empêche la formation d'un arc électrique entre le support 6 et l'anode 2.This particular provision prevents the formation of a electric arc between support 6 and anode 2.

Le fonctionnement de cette torche est le suivant.The operation of this torch is as follows.

Une différence de potentiel électrique de l'ordre de 20 kilo volts est appliquée entre l'anode 2 et la cathode 3.A difference in electrical potential of around 20 kilo volts is applied between anode 2 and cathode 3.

Le courant est appliqué à l'anode par le contact électrique 11 et à la cathode par le support 6 et la bague de contact 34.Current is applied to the anode by contact 11 and to the cathode by the support 6 and the ring contact 34.

L'isolation électrique est assurée par la gaine 36 entourant le contact 11, le manchon isolant 27, les joints toriques 29,30 et 31 et le fourreau isolant 19.The electrical insulation is ensured by the sheath 36 surrounding the contact 11, the insulating sleeve 27, the seals O-rings 29, 30 and 31 and the insulating sleeve 19.

Ainsi anode et cathode ne sont reliées entre elles que par le fusible disposé à l'intérieur du capillaire 4. Ce fusible amorce un arc électrique entre anode et cathode, arc qui se maintien et provoque l'ablation du matériau du capillaire et la génération d'un plasma qui sort de la torche 1 par l'orifice axial 24.Thus anode and cathode are only connected to each other by the fuse placed inside the capillary 4. This fuse initiates an electric arc between anode and cathode, arc which is maintained and causes the ablation of the material of the capillary and the generation of a plasma that comes out of the torch 1 through the axial hole 24.

Du fait de son caractère monobloc au niveau de son fond 10, l'anode 2 proposée par l'invention permet d'éviter toute fuite de plasma vers l'arrière de la torche (vers le contact 11).Due to its one-piece nature at the bottom 10, the anode 2 proposed by the invention makes it possible to avoid any plasma leakage towards the rear of the torch (towards the contact 11).

Elle permet également d'améliorer la résistance mécanique de la torche, car celle ci possède alors une structure massive et monobloc à l'emplacement où la pression engendrée est maximale, c'est à dire au niveau du fond 10 de l'anode 2.It also improves mechanical strength of the torch, because it then has a structure massive and monobloc at the location where the pressure generated is maximum, that is to say at the bottom 10 of the anode 2.

Le corps cylindrique 12 de l'anode 2 entoure le capillaire 4 sur toute sa longueur. Il assure le maintien radial de celui ci malgré les fortes pressions développées à l'intérieur de la torche. Il en résulte une excellente tenue mécanique de la torche avec un encombrement radial minimal.The cylindrical body 12 of the anode 2 surrounds the capillary 4 over its entire length. It ensures the maintenance radial of this one despite the strong pressures developed at inside the torch. This results in excellent hold mechanical torch with minimal radial bulk.

La torche selon l'invention peut être utilisée dans le domaine de l'armement pour le tir de projectiles à vitesses importantes (supérieures à 2000 m/s).The torch according to the invention can be used in the armament field for firing high-speed projectiles significant (greater than 2000 m / s).

Elle peut également être utilisée dans le domaine civil pour les opérations de découpe ou destruction de matériaux ou pour réaliser des dépôts de matériaux.It can also be used in the civil field for cutting or destroying materials or to make deposits of materials.

Claims (9)

Torche à plasma (1) comprenant une anode (2) et une cathode (3) séparées par un tube capillaire (4) réalisé en un matériau isolant électrique et ablatable par l'action du plasma, torche caractérisée en ce que l'anode (2) comporte un étui conducteur (12) fermé à une première extrémité (10), étui à l'intérieur duquel est disposé le tube capillaire (4).Plasma torch (1) comprising an anode (2) and a cathode (3) separated by a capillary tube (4) made of an electrically insulating material and ablatable by the action of plasma, torch characterized in that the anode ( 2) comprises a conductive case (12) closed at a first end (10), a case inside which the capillary tube (4) is disposed. Torche à plasma selon la revendication 1, caractérisée en ce que le tube capillaire (4) est séparé de l'anode (2) par un fourreau isolant (19).Plasma torch according to claim 1, characterized in that the capillary tube (4) is separated from the anode (2) by an insulating sleeve (19). Torche à plasma selon la revendication 2, caractérisée en ce que l'étui de l'anode s'étend longitudinalement sensiblement jusqu'à la cathode (3), le fourreau isolant (19) entourant au moins partiellement la cathode (3).Plasma torch according to claim 2, characterized in that the anode case extends longitudinally substantially to the cathode (3), the insulating sheath (19) at least partially surrounding the cathode (3). Torche à plasma selon la revendication 3, caractérisée en ce que la cathode (3) comporte une portée conique (17) qui vient se positionner dans un logement complémentaire conique (16) de l'étui conducteur, le fourreau isolant (19) comportant une partie évasée (20) qui est interposée entre la portée conique de la cathode et le logement conique (16) de l'étui conducteur.Plasma torch according to claim 3, characterized in that the cathode (3) has a conical bearing (17) which is positioned in a complementary conical housing (16) of the conductive case, the insulating sheath (19) comprising a flared part (20) which is interposed between the conical bearing of the cathode and the conical housing (16) of the conductive case. Torcha à plasma selon une des revendications 1 à 4, caractérisée en ce que l'anode (2) comporte un culot (14) formant pied d'arc disposé au fond de l'étui conducteur.Plasma torcha according to one of Claims 1 to 4, characterized in that the anode (2) has a base (14) forming an arc foot arranged at the bottom of the conductive case. Torche à plasma selon une des revendications 2 à 5, caractérisée en ce que la cathode (3) comporte une lèvre d'étanchéité annulaire (18) qui est appliquée contre le fourreau isolant (19) et qui délimite un alésage recevant une extrémité (21) à diamètre réduit du capillaire (4).Plasma torch according to one of Claims 2 to 5, characterized in that the cathode (3) has a lip annular seal (18) which is applied against the insulating sleeve (19) and which delimits a bore receiving a end (21) of reduced diameter of the capillary (4). Torche à plasma selon une des revendications 1 à 6, caractérisée en ce que la cathode (3) comporte un logement axial (22) dans lequel est disposé un anneau conducteur (23) formant pied d'arc.Plasma torch according to one of Claims 1 to 6, characterized in that the cathode (3) has a housing axial (22) in which a conductive ring (23) is arranged forming an arc foot. Torche à plasma selon une des revendications 1 à 7, caractérisée en ce qu'elle comporte un manchon tubulaire isolant (27) entourant l'anode (2) et assurant sa solidarisation avec la cathode (3). Plasma torch according to one of Claims 1 to 7, characterized in that it comprises a tubular sleeve insulator (27) surrounding the anode (2) and ensuring its secured to the cathode (3). Torche à plasma selon la revendication 8, caractérisée en ce qu'elle comporte au moins un joint torique (29,30,31) disposé entre le manchon tubulaire (27) et le fourreau isolant (19).Plasma torch according to claim 8, characterized in that it comprises at least one O-ring (29,30,31) disposed between the tubular sleeve (27) and the sleeve insulator (19).
EP97402414A 1996-10-18 1997-10-14 Plasma torch with new sealing features Expired - Lifetime EP0837621B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9612680A FR2754969B1 (en) 1996-10-18 1996-10-18 IMPROVED SEALING PLASMA TORCH
FR9612680 1996-10-18
US08/954,036 US5938950A (en) 1996-10-18 1997-10-20 Plasma torch with improved gas-tightness

Publications (2)

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EP0837621A1 true EP0837621A1 (en) 1998-04-22
EP0837621B1 EP0837621B1 (en) 2003-02-19

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EP (1) EP0837621B1 (en)
FR (1) FR2754969B1 (en)

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FR2827039B1 (en) 2001-07-06 2003-11-28 Giat Ind Sa IGNITION DEVICE FOR PROPULSIVE CHARGING
FR2844873B1 (en) * 2002-09-25 2006-11-24 Giat Ind Sa DOUBLE EFFECT INFLAMMATOR AND IGNITION METHOD USING SUCH AN INFLAMMATOR
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US7091441B1 (en) * 2004-03-19 2006-08-15 Polytechnic University Portable arc-seeded microwave plasma torch
EP1689216A1 (en) * 2005-02-04 2006-08-09 Vlaamse Instelling Voor Technologisch Onderzoek (Vito) Atmospheric-pressure plasma jet
SE533831C2 (en) * 2005-03-15 2011-02-01 Bae Systems Bofors Ab Plasma lighters for an electrochemical-chemical (ETK) cannon, bullet gun or other firearm weapon of similar type
CN102897892B (en) * 2012-10-26 2013-10-16 清华大学 Enhanced-type capillary-needle discharging plasma water treatment device
US11617610B2 (en) 2018-04-26 2023-04-04 Us Patent Innovations Llc System and method for micro-sized cold atmospheric plasma treatment

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Also Published As

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EP0837621B1 (en) 2003-02-19
US5938950A (en) 1999-08-17
FR2754969B1 (en) 1998-11-27
FR2754969A1 (en) 1998-04-24

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