EP0135826B1 - Apparatus for thermally spraying coating plasma - Google Patents

Apparatus for thermally spraying coating plasma Download PDF

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Publication number
EP0135826B1
EP0135826B1 EP84110175A EP84110175A EP0135826B1 EP 0135826 B1 EP0135826 B1 EP 0135826B1 EP 84110175 A EP84110175 A EP 84110175A EP 84110175 A EP84110175 A EP 84110175A EP 0135826 B1 EP0135826 B1 EP 0135826B1
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EP
European Patent Office
Prior art keywords
nozzle
combustion chamber
focussing
gas
ignition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP84110175A
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German (de)
French (fr)
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EP0135826A1 (en
Inventor
Manfred Oechsle
Uwe Szieslo
Karl-Peter Streb
Wolfgang Simm
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ECG Immobilier SA
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Castolin SA
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Priority to AT84110175T priority Critical patent/ATE24420T1/en
Publication of EP0135826A1 publication Critical patent/EP0135826A1/en
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Publication of EP0135826B1 publication Critical patent/EP0135826B1/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
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/42—Plasma torches using an arc with provisions for introducing materials into the plasma, e.g. powder, liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
    • B05B7/20—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed by flame or combustion
    • B05B7/201—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed by flame or combustion downstream of the nozzle
    • B05B7/205—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed by flame or combustion downstream of the nozzle the material to be sprayed being originally a particulate material
    • 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
    • H05H1/36—Circuit arrangements

Definitions

  • the invention relates to a device for the thermal spraying of build-up welding materials, consisting of a coolable beam bundling nozzle with a space on the loading side for accommodating devices for controllable supply of the operating components, namely operating gases and build-up welding material, cf. DE-B-1 089614.
  • the mouth of the carrier gas powder outlet channel is arranged directly in the region of the junction into the jet bundling channel of the bundling nozzle, the expanded space around the nozzle only serving to supply oxygen, which is mixed into the carrier gas powder stream through an annular gap.
  • the nozzle is not designed to be adjustable, so that there are no possibilities for adaptation to different powders.
  • the entire device must be ignited from the front, which is also not without danger.
  • the invention is accordingly based on the object. to create a device working with comparable low spray losses.
  • which, working according to the so-called differential pressure principle, on the one hand does not require or does not require much more than previously required for flame spraying in terms of its outlay in terms of apparatus, and on the other hand the use of all combustible gases when the combustion chamber is adapted variably.
  • acetylene and different spray powders are also permitted and with which, in particular, the ignition or start-up process should also be controllable.
  • the extended space is designed as a combustion chamber with a flow-accelerating transition contour for the confluence of the bundling nozzle and in the combustion chamber with respect to the confluence of the jet bundling nozzle and an axially adjustable, differential pressure-charged burner nozzle or a Nozzle holder with a nozzle is arranged and that furthermore an ignition electrode which can be set on the nozzle is arranged in the wall of the combustion chamber and this is provided with a switching element which switches on the electrode after the flushing of the bundling nozzle and before the supply of the fuel gas.
  • the solution given is easiest to implement by combining the jet nozzle with a flame spray gun in such a way that the variability of the combustion chamber volume is retained. However, one remains dependent on the performance data of the spray gun used in each case. If you do not want this and can process wire as a spray additive in addition to powder, the nozzle holder is designed as a correspondingly adapted nozzle assembly while maintaining the basic principle.
  • the solution according to the invention results in the following advantages with regard to the application layers: With high-melting materials (oxides, cermets, high-melting metals, etc.), it has been shown that a significantly better layer quality can be achieved. The tightness in the application layer is significantly increased compared to conventional flame spray applications.
  • the adhesive strength is also significantly improved due to the higher kinetic energy of the spray particles, and there is also no impairment of the sprayed-on layer by powder particles which have baked in the beam-bundling channel and which sooner or later become detached again.
  • bundling the spray jet the otherwise unavoidable spray losses for targeted applications are significantly reduced.
  • the ignition device equipped with an electrode it has also proven essential for the device's long-term operability to be able to withdraw the electrode from the combustion chamber after it has been ignited, in order not to disturb the flow in the combustion chamber on the one hand and on the other to not to hinder the adaptation of the combustion chamber volume to the respective circumstances.
  • combustion chamber wall is also designed to be coolable.
  • the combustion chamber volume is variable due to the adjustability of the nozzle or the nozzle assembly, the residence time of the powder particles in the combustion chamber can thereby be influenced; that is, the powder is preheated in an adapted manner or brought to the desired temperature in a targeted manner before it reaches the jet bundling nozzle at high speed.
  • a flow-accelerating transition contour is present between the combustion chamber and the junction into the beam bundling channel, and advantageously with respect to the device axis with a convex shape, which is of particular importance in the present case as far as otherwise because the powder particles emerge at least already melted out of the combustion chamber, the powder particles can already start in the junction area of the beam focusing channel. If this area does not fully grow when the flow is unfavorable, such approaches lead to the risk of tearing off and if such tearing particles get into the application layer, this does not lead to optimal coating results.
  • both high-melting and low-melting spray additives can be sprayed, and finally there is the possibility of supplying atomizing or additional gases, which make it possible to influence the operation of the device in a targeted manner.
  • the beam bundling nozzle is therefore advantageously designed in several parts, which will be explained in more detail.
  • the device When the device is designed with a nozzle assembly, powder conveyance is carried out by an external powder conveying system during powder spraying, so that uniform powder conveyance is made possible.
  • the wire In the case of processing wire as a spray additive, the wire is also fed via an external feed device of known type for the wire.
  • additional devices for forming such a jacket flow can then also be made in the half on the confluence, preferably in the area before the confluence, which can also be generated, for example, by supplying inert gas.
  • the injected gas which may also be a fuel gas, then forms a cladding layer in the channel, and baking of molten particles is practically no longer possible.
  • the inner channel of the jet bundling nozzle does not have to be cylindrical, but can also be designed to widen conically towards the nozzle mouth.
  • What is essential for the device according to the invention is therefore the formation of a combustion chamber in which the outlet nozzle for the fuel gases and the carrier gas stream is arranged so as to be adjustable in the longitudinal direction.
  • the size of the combustion chamber is therefore variable and only the gases burned out in the combustion chamber reach the beam bundle channel under acceleration. Since the powder particles thus also only get into the combustion chamber, they are melted or melted there in an adapted manner and in this state reach the bundling channel.
  • the arrangement of a retractable ignition electrode in the combustion chamber is essential in order to ensure the ignition of only a relatively small mixture of fuel gas in the combustion chamber when the device is started up.
  • the essential parts of the device are the flame spray gun 6 ′′, which is only indicated by dashed lines, an adapter 3 containing the combustion chamber 2, the beam focusing nozzle 1 and the ignition device with electrode 7.
  • the flame spray gun 6 ′′ requires no further explanation, as is known per se .
  • the adapter 3 must of course be dimensioned with respect to its receiving bore so that the head 6 'of the flame spray gun 6 ", in which the burner nozzle 5 is seated, can be used in the adapter 3, specifically with suitable elements in different positions to fix the To be able to adapt combustion chamber 2 to the respective requirements, the ignition device with the ignition electrode 7 also being adjustable with respect to its longitudinal axis, so that the suitable ignition distance to the nozzle 5 can be set and an ignition arc or ignition spark can occur briefly for ignition .
  • the ignition device is designed as follows:
  • the electrode 7 forms the armature of a magnetic coil 11 which, when excited, brings the electrode 7 into the ignition position (dashed line) to the nozzle 5 against the action of a return spring 12
  • the ignition current is switched on by a limit switch 13 (FIG. 6).
  • the electrode 7 is reset from the combustion chamber 2 by the spring 12. It is essential for the ignition process that the ignition does not take place only when the combustion chamber 2 is filled, but immediately at the beginning of the inflow of an ignitable gas mixture into the combustion chamber.
  • the beam bundling nozzle 1 including the adapter 3 is water-cooled, the cooling channels 14, 15 being connected to a connecting line 16.
  • the coolant inflow connection 17 for both cooling channels 14, 15 is arranged in the attachment area of the jet bundling nozzle 18 to the adapter 3, and a common coolant outflow connection 19 is provided for both channels 14, 15.
  • the beam bundling nozzle 1 can be formed from individual parts 22 which can be connected to one another and which are connected to one another with regard to the passage of coolant by bypass lines 23, provided that not every individual part 22 is provided with separate inlet and outlet connections.
  • one or more gas supply openings 21 are provided at the end on the adapter side, as shown schematically in FIG. 4.
  • openings 21 ' can additionally be provided in the region of the mouth-side half of the jet bundling nozzle 1, for example in the flow shadow of a gradation 24 (on the right in FIG. 4).
  • the part which is movable or adjustable with respect to the combustion chamber 2 (flame spray gun 6 "or nozzle holder 6 according to FIG. 2) is advantageously provided with a marking or with an adjustable stop in order to ensure that the part in question with its for the ignition process Nozzle 5 is brought into the correct ignition distance from electrode 7.
  • the ignition device or the electrode 7 is expediently arranged in the plug-in region 3 'of the adapter 3 containing the combustion chamber 2, so that the access opening in the adapter wall for the electrode 7 is covered even when the volume of the combustion chamber 2 is set to the greatest extent, which is in consideration of the high temperatures in the combustion chamber 2 is advantageous.
  • the embodiment according to FIG. 2 differs from that described in FIG. 1 practically only in that instead of the spray gun a correspondingly adapted nozzle assembly or nozzle holder 6 is provided and one is no longer bound to the performance data of the flame spray gun 6 " 2, the conveying elements for the wire-shaped spray material are not shown for the flame spray gun and the nozzle holder according to FIG. 2, since such elements are generally known.
  • the nozzle holder 6 according to FIG A connection for a powder storage container or for a powder supply line can be equipped with the corresponding parts of this embodiment according to Fig. 2 with corresponding reference numerals which are provided with a dash index.
  • the flame spray gun or the nozzle assembly, the electrode and corresponding connecting lines are not shown.
  • the convex design of the transition contour 4 ′ from the combustion chamber 2 into the beam bundling channel 25 can be seen particularly clearly here, which widens somewhat conically toward the mouth 26.
  • Such an extension can also be provided in the embodiments according to FIGS. 1, 2.
  • the wall of the beam focusing channel 25 is formed as a molded body 27 made of porous, gas-permeable material.
  • the porous molded body 27 is surrounded by a cavity 28 which can be charged with compressed gas and to which the compressed gas is fed through a compressed gas charging connection 29.
  • the molded body 27 is, for example, formed of a sintered Al 2 0 3 or Zr0 3 or mixed forms thereof. Since the molded body 27 is gas-permeable over its entire surface, a constantly renewing gas cushion is formed in the sense of the aforementioned jacket flow, it being entirely possible to additionally arrange openings 21 in the immediate vicinity of the overflow contour 4 '.
  • the compressed gas supplied through the connection 29 can also be a fuel gas which provides for an additional acceleration of the entire flow in the beam focusing channel 25.
  • Corresponding relays K s , K 2 , K 3 , K 4 and corresponding circuit elements delayed on and off delay ensure the necessary functional sequence on the device according to FIG. 7, t 3 representing the actual operating phase.
  • the curves shown are of course only of qualitative importance.
  • E.g. illustrates the ignition curve that the ignition current only flows in the time interval t 2 , in which the fuel gas only begins to flow in.
  • the electrode curve shows that the electrode is withdrawn immediately after the interval t 2 .
  • the fuel gas supply drops immediately, but the oxygen supply can continue to run a little for purging purposes.

Abstract

PCT No. PCT/DE84/00173 Sec. 371 Date Apr. 24, 1985 Sec. 102(e) Date Apr. 24, 1985 PCT Filed Aug. 27, 1984 PCT Pub. No. WO85/00991 PCT Pub. Date Mar. 14, 1985.A spray gun comprises a nozzle defining an elongated, axially extending spray channel, a coaxial inlet leading thereto and having a flow-accelerating contour, and a coaxial combustion chamber leading to the inlet, the combustion chamber having a diameter larger than that of the spray channel. A nozzle head is displaceably mounted in the combustion chamber and is axially adjustable with respect to the inlet, the nozzle head feeding the fusible material into the combustion chamber and carrying a burner nozzle and respective conduits feeding a combustion gas and a spray channel flushing gas into the combustion chamber. An ignition electrode projects into the combustion chamber and is arranged for adjustment with respect to the burner nozzle in a direction transverse to the axis, and a control circuit comprises a switching element for supplying electric current to the ignition electrode whereby a spark is formed between the ignition electrode and the burner nozzle for igniting the combustion gas in the combustion chamber, and respective controllers for feeding the combustion gas and the flushing gas through the respective conduits, the control circuit sequentially operating the controller for feeding the flushing gas, the switching element for supplying electric current to the ignition electrode and the controller for feeding the combustion gas.

Description

Die Erfindung betrifft eine Vorrichtung zum thermischen Spritzen von Auftragsschweißwerkstoffen, bestehend aus einer kühlbaren Strahlbündelungsdüse mit einem beschickungsseitig erweiterten Raum zur Aufnahme von Einrichtungen zur regelbaren Zuführung der Betriebskomponenten, nämlich Betriebsgasen und Auftragsschweißwerkstoff, vgl. DE-B-1 089614.The invention relates to a device for the thermal spraying of build-up welding materials, consisting of a coolable beam bundling nozzle with a space on the loading side for accommodating devices for controllable supply of the operating components, namely operating gases and build-up welding material, cf. DE-B-1 089614.

Vorrichtungen der genannten Art sind für das thermische Spritzen zum Auftragen von Pulvern nach der DE-B-1 089 614 bekannt. Der weitere Stand der Technik wird durch die EP-A-0 049 915 und durch die Zeitschrift « Metall Heft 3/83. Seite 238. Fig. 1 repräsentiert. Bei der letztgenannten Vorrichtung wird Stickstoff als Fördergas benutzt, wobei die Flamme (Brenngas ist Gemisch aus Methylacetylenpropadien und Sauerstoff) in der wassergekühlten Strahlbündelungsdüse gebildet wird. Das Verfahren nach der EP-A-0 049 915 setzt ein aufwendiges Dosiersystem mit elektronischer Steuerung und Regelung voraus, d. h. die zugehörige genannte Anlage ist sehr teuer und deren Anschaffung und Einsatz lohnt sich nur für bestimmte Einsatzfälle, obgleich mit einer solchen Anlage (die Betriebsmittelkomponenten werden nach dem Gleichdruckprinzip zusammengeführt) Spritzqualitäten erreichbar sind, die einen Vergleich mit dem beim Plasma- und Flammschockspritzen erreichbaren Spritzqualitäten ohne weiteres aushalten, d. h. sehr hochwertig sind. Da diese Anlagen nicht unter Verwendung reinen Acetylens betrieben werden können und, wie erwähnt, sehr teuer sind, verbietet sich deren Verwendung für gewissermaßen normale Spritzauftragsfälle, d. h. für solche Fälle konnte man mit einfacheren Mitteln, die mit einem solchen Verfahren und einer solchen Strahlbündelungsdüse (Pinchdüse) verbundenen Vorteile, nämlich Vermeidung bzw. Reduktion von Spritzverlusten, bessere Partikelaufschmelzung und höhere Partikelbeschleunigung, bisher nicht ausnutzen.Devices of the type mentioned are known for thermal spraying for applying powders according to DE-B-1 089 614. The further state of the art is described in EP-A-0 049 915 and by the magazine «Metall Heft 3/83. Page 238. Fig. 1 represents. In the latter device, nitrogen is used as the conveying gas, the flame (fuel gas being a mixture of methylacetylene propadiene and oxygen) being formed in the water-cooled jet nozzle. The method according to EP-A-0 049 915 requires a complex dosing system with electronic control and regulation, i. H. the associated system mentioned is very expensive and its acquisition and use is only worthwhile for certain applications, although spraying qualities can be achieved with such a system (the equipment components are combined according to the constant pressure principle), which can be compared with the spraying qualities achievable with plasma and flame shock spraying without endure further, d. H. are very high quality. Since these systems cannot be operated using pure acetylene and, as mentioned, are very expensive, their use is impossible for somewhat normal spray application cases, i.e. H. For such cases, simpler means have so far not been able to take advantage of the advantages associated with such a method and such a beam bundling nozzle (pinch nozzle), namely avoidance or reduction of spray losses, better particle melting and higher particle acceleration.

Bei der Vorrichtung nach der eingangs genannten DE-B-1 089 614 ist keine Brennkammer vorhanden. sondern die Mündung des Trägergas-Pulveraustrittskanals ist unmittelbar im Bereich der Einmündung in den Strahlbündelungskanal der Bündelungsdüse angeordnet, wobei der erweiterte Raum um die Düse lediglich der Sauerstoffzufuhr dient, der durch einen Ringspalt dem Trägergas-Pulverstrom zugemischt wird. Abgesehen von der Rückzündgefahr in dem Trägergas-Pulverzufuhrkanal ist die Düse nicht verstellbar ausgebildet, so daß hierbei keine Anpassungsmöglichkeiten an differente Pulver sich ergeben. Außerdem muß die ganze Vorrichtung von vorn her gezündet werden, was ebenfalls nicht ungefährlich ist.There is no combustion chamber in the device according to DE-B-1 089 614 mentioned at the beginning. rather, the mouth of the carrier gas powder outlet channel is arranged directly in the region of the junction into the jet bundling channel of the bundling nozzle, the expanded space around the nozzle only serving to supply oxygen, which is mixed into the carrier gas powder stream through an annular gap. Apart from the risk of reignition in the carrier gas powder supply channel, the nozzle is not designed to be adjustable, so that there are no possibilities for adaptation to different powders. In addition, the entire device must be ignited from the front, which is also not without danger.

Der Erfindung liegt demgemäß die Aufgabe zugrunde. eine mit vergleichbar geringen Spritzverlusten arbeitende Vorrichtung zu schaffen. die, nach dem sogenannten Differenzdruckprinzip arbeitend, einerseits hinsichtlich ihres apparativen Aufwandes nicht bzw. nicht wesentlich mehr verlangt als bisher für das Flammspritzen erforderlich, die andererseits bei angepaßter Veränderbarkeit der Brennkammer die Verwendung aller brennbaren Gase. insbesondere aber auch Acetylen und differenter Spritzpulver erlaubt und mit der insbesondere auch der Zünd- bzw. Anfahrvorgang sicher beherrschbar sein soll.The invention is accordingly based on the object. to create a device working with comparable low spray losses. which, working according to the so-called differential pressure principle, on the one hand does not require or does not require much more than previously required for flame spraying in terms of its outlay in terms of apparatus, and on the other hand the use of all combustible gases when the combustion chamber is adapted variably. In particular, however, acetylene and different spray powders are also permitted and with which, in particular, the ignition or start-up process should also be controllable.

Diese Aufgabe ist mit einer Vorrichtung der eingangs genannten Art nach der Erfindung dadurch gelöst, daß der erweiterte Raum als Brennkammer mit strömungsbeschleunigender Übergangskontur zur Einmündung der Bündelungsdüse ausgebildet und in der Brennkammer in bezug auf die Einmündung der Strahlbündelungsdüse eine axial verstellbare, differenzdruckbeschickte Brennerdüse bzw. ein Düsenhalter mit Düse angeordnet ist und daß ferner in der Wand der Brennkammer eine auf die Düse einstellbare Zündelektrode angeordnet und diese mit einem die Elektrode nach der Spülung der Bündelungsdüse und vor der Zufuhr des Brenngases einschaltendem Schaltelement versehen ist. Vorteilhafte Weiterbildungen dieser Lösung ergeben sich nach den Unteransprüchen 2 bis 14.This object is achieved with a device of the type mentioned according to the invention in that the extended space is designed as a combustion chamber with a flow-accelerating transition contour for the confluence of the bundling nozzle and in the combustion chamber with respect to the confluence of the jet bundling nozzle and an axially adjustable, differential pressure-charged burner nozzle or a Nozzle holder with a nozzle is arranged and that furthermore an ignition electrode which can be set on the nozzle is arranged in the wall of the combustion chamber and this is provided with a switching element which switches on the electrode after the flushing of the bundling nozzle and before the supply of the fuel gas. Advantageous further developments of this solution result from subclaims 2 to 14.

Die gegebene Lösung ist am einfachsten zu verwirklichen, indem man die Strahlbündelungsdüse mit einer Flammspritzpistole kombiniert und zwar derart, daß die Veränderbarkeit des Brennkammervolumens erhalten bleibt. Dabei bleibt man allerdings von den Leistungsdaten der jeweils verwendeten Spritzpistole abhängig. Will man dies nicht und außer Pulver auch Draht als Spritzzusatzwerkstoff verarbeiten können, so wird der Düsenhalter als entsprechend angepaßter Düsenstock unter Beibehaltung des Grundprinzips ausgebildet.The solution given is easiest to implement by combining the jet nozzle with a flame spray gun in such a way that the variability of the combustion chamber volume is retained. However, one remains dependent on the performance data of the spray gun used in each case. If you do not want this and can process wire as a spray additive in addition to powder, the nozzle holder is designed as a correspondingly adapted nozzle assembly while maintaining the basic principle.

Durch die erfindungsgemäße Lösung ergeben sich hinsichtlich der Auftragsschichten folgende Vorteile : Bei hochschmelzenden Werkstoffen (Oxide, Cermets, hochschmelzende Metalle usw.) kann, wie sich gezeigt hat, eine wesentlich bessere Schichtqualität erzielt werden. Die Dichtigkeit in der Auftragsschicht wird gegenüber herkömmlichen Flammspritzäufträgen wesentlich erhöht.The solution according to the invention results in the following advantages with regard to the application layers: With high-melting materials (oxides, cermets, high-melting metals, etc.), it has been shown that a significantly better layer quality can be achieved. The tightness in the application layer is significantly increased compared to conventional flame spray applications.

Die Haftfestigkeit ist aufgrund der höheren kinetischen Energie der Spritzpartikel ebenfalls wesentlich verbessert, und es treten auch keine Beeinträchtigungen der aufgespritzten Schicht durch im Strahlbündelungskanal angebackene und sich früher oder später wieder ablösende Pulverpartikel auf. Durch die Bündelung des Spritzstrahles sind die sonst unvermeidbaren Spritzverluste für gezielte Auftragungen wesentlich vermindert.The adhesive strength is also significantly improved due to the higher kinetic energy of the spray particles, and there is also no impairment of the sprayed-on layer by powder particles which have baked in the beam-bundling channel and which sooner or later become detached again. By bundling the spray jet, the otherwise unavoidable spray losses for targeted applications are significantly reduced.

Es können bisher auch mit einer Flammspritzpistole allein nicht zu verspritzende Zusatzwerkstoffe eingesetzt werden. Ferner ist auch die Forderung nach der Verwendbarkeit aller in diesem Arbeitsbereich üblichen Brenngase insbesondere von Acetylen durch entsprechend optimal mögliche Einstellung des Brennkammervolumens erfüllt und schließlich verlangt der Betrieb einer solchen Vorrichtung keine aufwendige elektronische Steuerung, sondern nur eine einfache elektrische Schaltung und Regelung für die Gewährleistung der folgerichtigen 'Schritte zum Zünden. Für die betriebssichere Zündung bei Inbetriebnahme und somit für die Brauchbarkeit der Vorrichtung überhaupt ist es nämlich wesentlich, daß diese in folgenden Schritten vollzogen wird, um das brennbare Gas-Sauerstoff-Gemisch für die Anfahrphase auf ein Minimum zu reduzieren : Spülen mit reinem Sauerstoff. Wirksammachen der Zündeinrichtung und erst dann Zuführung des Brenngases. Würde diese Reihenfolge nicht eingehalten, so führt dies bei Zündung unmittelbar vor der Düse der Flammspritzpistole zu einer Explosion ggf. mit Auslöschen der Flamme oder bei Zündung an der Ausmündung der Strahlbündelungsdüse, wie das bei der Vorrichtung nach der DAS der Fall ist. zu einer Rückzündung in die Düse hinein und zu einem Verlöschen der Flamme. Diese für die Anfahrphase also wesentliche Reihenfolge ließe sich zwar an der Flammspritzpistole für die Gaszufuhr von Hand manipulieren, und zwar einschließlich der Einschaltung der Zündeinrichtung an der erfindungsgemäßen Vorrichtung, dies wäre aber zu umständlich und zu unsicher.Up to now, filler materials that cannot be sprayed alone can also be used with a flame spray gun. Furthermore, there is also the requirement for the usability of all the combustion gases customary in this work area, in particular acetylene, by setting the combustion chamber volume in a correspondingly optimal manner Finally, the operation of such a device does not require complex electronic control, but only a simple electrical circuit and regulation to ensure the consequent steps for ignition. For reliable ignition during commissioning and thus for the usability of the device in general, it is essential that it is carried out in the following steps in order to reduce the combustible gas-oxygen mixture to a minimum for the start-up phase: Flushing with pure oxygen. Make the ignition device effective and only then supply the fuel gas. If this sequence is not followed, an ignition directly in front of the nozzle of the flame spray gun leads to an explosion, possibly with extinguishing of the flame, or ignition at the mouth of the jet nozzle, as is the case with the device according to the DAS. to re-ignite into the nozzle and to extinguish the flame. This sequence, which is essential for the start-up phase, could be manipulated by hand on the flame spray gun for the gas supply, including switching on the ignition device on the device according to the invention, but this would be too cumbersome and too unsafe.

Bezüglich der mit einer Elektrode ausgestatteten Zündeinrichtung hat sich auch für eine dauernde Betriebsfähigkeit der Vorrichtung als wesentlich erwiesen, die Elektrode nach erfolgter Zündung aus der Brennkammer zurückziehen zu können, dies auch, um einerseits die Strömung in der Brennkammer nicht zu stören und zum anderen, um die Anpassung des BrennKammervolumens an die jeweiligen Gegebenheiten nicht zu behindern. In der Praxis bedeutet dies, daß die Düse und die Elektrode auf Zündstellung zusammengefahren werden und daß danach, je nach den Erfordernissen, das optimale Brennkammervolumen unbehindert von der Elektrode eingestellt werden kann.With regard to the ignition device equipped with an electrode, it has also proven essential for the device's long-term operability to be able to withdraw the electrode from the combustion chamber after it has been ignited, in order not to disturb the flow in the combustion chamber on the one hand and on the other to not to hinder the adaptation of the combustion chamber volume to the respective circumstances. In practice, this means that the nozzle and the electrode are moved to the ignition position and that, depending on the requirements, the optimum combustion chamber volume can then be set unhindered by the electrode.

In der Brennraumkammer, die bezüglich ihrer Größe auch bei der Flammspritzpistolen/Strahlbündelungsdüsen-Kombination variierbar sein muß, findet eine weitgehend kontrollierte Verbrennung der gemischten Gase statt, die ggf. zu Temperaturen führen kann, bei denen sogar Metallverdampfungen auftreten. Aus diesem Grunde ist auch die Brennkammerwand kühlbar ausgebildet.A largely controlled combustion of the mixed gases takes place in the combustion chamber, the size of which must also be variable in the case of the flame spray guns / beam bundling nozzle combination, which can possibly lead to temperatures at which even metal evaporation occurs. For this reason, the combustion chamber wall is also designed to be coolable.

Da bei der erfindungsgemäße Vorrichtung das Brennkammervolumen durch die Einstellbarkeit der Düse bzw. des Düsenstockes variabel ist, kann dadurch auf die Verweilzeit der Pulverpartikel in der Brennkammer Einfluß genommen werden, d. h., das Pulver wird angepaßt vorgewärmt bzw. gezielt auf gewünschte Temperatur gebracht und zwar noch ehe es hochbeschleunigt in die Strahlbündelungsdüse gelangt. In diesem Zusammenhang ist es wesentlich, daß zwischen Brennkammer und Einmündung in den Strahlbündelungskanal eine strömungsbeschleunigende Übergangskontur vorhanden ist, und zwar vorteilhaft in bezug auf die Vorrichtungsachse mit konvexer Formgebung, was im vorliegenden Fall insofern von besonderer Bedeutung ist, als sich sonst, da die Pulverpartikel schon mindestens angeschmolzen aus der Brennkammer austreten, die Pulverpartikel schon im Einmündungsbereich des Strahlbündelungskanales ansetzen können. Falls dieser Bereich bei strömungsungünstiger Ausbildung nicht ganz zuwächst, führen solche Ansätze zur Gefahr des Abreißens und wenn solche Abrißpartikel in die Auftragsschicht gelangen, führt dies nicht zu optimalen Beschichtungsergebnissen.Since in the device according to the invention the combustion chamber volume is variable due to the adjustability of the nozzle or the nozzle assembly, the residence time of the powder particles in the combustion chamber can thereby be influenced; that is, the powder is preheated in an adapted manner or brought to the desired temperature in a targeted manner before it reaches the jet bundling nozzle at high speed. In this context, it is essential that a flow-accelerating transition contour is present between the combustion chamber and the junction into the beam bundling channel, and advantageously with respect to the device axis with a convex shape, which is of particular importance in the present case as far as otherwise because the powder particles emerge at least already melted out of the combustion chamber, the powder particles can already start in the junction area of the beam focusing channel. If this area does not fully grow when the flow is unfavorable, such approaches lead to the risk of tearing off and if such tearing particles get into the application layer, this does not lead to optimal coating results.

Durch Veränderung der Brennkammergröße, ggf. aber auch Veränderung der Länge der Strahlbündelungsdüse, können sowohl hochschmelzende als auch niedrigschmelzende Spritzzusatzwerkstoffe verspritzt werden, und schließlich ist die Möglichkeit der Zuführung von Zerstäuber- bzw. Zusatzgasen gegeben, die die Wirkungsweise der Vorrichtung gezielt beeinflußbar machen.By changing the size of the combustion chamber, but possibly also changing the length of the jet bundling nozzle, both high-melting and low-melting spray additives can be sprayed, and finally there is the possibility of supplying atomizing or additional gases, which make it possible to influence the operation of the device in a targeted manner.

Bezüglich der Längenanpassung zum zu verarbeitenden Spritzwerkstoff ist deshalb die Strahlbündelungsdüse vorteilhaft mehrteilig ausgebildet, was noch näher erläutert wird.With regard to the length adjustment to the spray material to be processed, the beam bundling nozzle is therefore advantageously designed in several parts, which will be explained in more detail.

Bei der Ausbildung der Vorrichtung mit einem Düsenstock wird beim Pulverspritzen die Pulverförderung von einem externen Pulverfördersystem übernommen, so daß eine gleichmäßige Pulverförderung ermöglicht wird. Im Falle der Verarbeitung von Draht als Spritzzusatzwerkstoff erfolgt die Drahtzuführung ebenfalls über ein externes Vorschubgerät bekannter Art für den Draht.When the device is designed with a nozzle assembly, powder conveyance is carried out by an external powder conveying system during powder spraying, so that uniform powder conveyance is made possible. In the case of processing wire as a spray additive, the wire is also fed via an external feed device of known type for the wire.

Insbesondere für eine längere Benutzungsdauer der Vorrichtung, auch dies gilt für beide Varianten, hat es sich als vorteilhaft erwiesen, im Innenkanal der Strahlbündelungsdüse für die Ausbildung einer Mantelströmung zu sorgen, was apparativ einfach zu verwirklichen ist. Durch eine solche Mantelströmung kann nämlich ein Anbacken der aufgeschmolzenen Partikel an den Wänden des Innenkanales verhindert werden, was für eine längere Betriebsdauer wesentlich ist.In particular for a longer period of use of the device, this also applies to both variants, it has proven to be advantageous to provide for the formation of a jacket flow in the inner channel of the jet bundling nozzle, which is easy to implement in terms of apparatus. Such a jacket flow can prevent the melted particles from caking on the walls of the inner channel, which is essential for a longer operating time.

Je nach der Länge der Strahlbündelungsdüse können dann auch in der einmündungsseitigen Hälfte, vorzugsweise im Bereich vor der Einmündung, zusätzliche Einrichtungen zur Ausbildung einer solchen Mantelströmung getroffen werden, die bspw. auch durch Zufuhr von Inertgas erzeugt werden kann. Außerdem ist es aber auch möglich, mindestens einen Teil der Wand des Strahlbündelungskanals aus porösem Material zu bilden (bspw. Keramik) und diesen Formkörper mit einem mit Druckgas beschickbaren Hohlraum zu umgeben. Das eingepreßte Gas, das ggf. auch ein Brenngas sei kann, bildet dann eine Mantelschicht im Kanal, und ein Anbacken geschmolzener Partikel ist praktisch nicht mehr möglich.Depending on the length of the jet bundling nozzle, additional devices for forming such a jacket flow can then also be made in the half on the confluence, preferably in the area before the confluence, which can also be generated, for example, by supplying inert gas. In addition, however, it is also possible to form at least part of the wall of the beam bundling channel from porous material (for example ceramic) and to surround this shaped body with a cavity which can be filled with compressed gas. The injected gas, which may also be a fuel gas, then forms a cladding layer in the channel, and baking of molten particles is practically no longer possible.

Im übrigen muß einerseits der Innenkanal der Strahlbündelungsdüse nicht zylindrisch, sondern kann auch sich zur Düsenmündung hin konisch erweiternd ausgebildet sein.For the rest, the inner channel of the jet bundling nozzle does not have to be cylindrical, but can also be designed to widen conically towards the nozzle mouth.

Abgesehen von den praktischen Ausführungsformen, die im einzelnen noch erläutert werden, und den vorteilhaften Weiterbildungen, ist mit der erfindungsgemäßen Lösung eine in ihrer Konstruktion denkbar einfache Vorrichtung geschaffen, deren einer Teil sogar eine herkömmliche Flammspritzpistole sein kann, die durch einfache Anpaßbarkeit des Brennkammervolumens allen auf diesem Gebiet üblichen Brenngasen bzw. Brenngasgemischen zugänglich ist und die einen sicheren Zündvorgang gewährleistet.Apart from the practical execution forms, which will be explained in more detail, and the advantageous developments, with the solution according to the invention a conceivably simple device is created in its construction, a part of which can even be a conventional flame spray gun, which is easy to adapt the combustion chamber volume to all common combustion gases in this field or fuel gas mixtures is accessible and which ensures a safe ignition process.

Wesentlich für die erfindungsgemäße Vorrichtung ist also die Ausbildung einer Brennkammer, in der in Längsrichtung verstellbar die Austrittsdüse für die Brenngase und den Trägergasstrom angeordnet ist. Die Größe der Brennkammer ist also variabel und erst die in der Brennkammer ausgebrannten Gase gelangen unter Beschleunigung in den Strahlbündelungskanal. Da die Pulverpartikel somit ebenfalls erst in die Brennkammer gelangen, werden diese dort angepaßt an- bzw. aufgeschmolzen und gelangen in diesem Zustand in den Bündelungskanal. Ferner ist wesentlich die Anordnung einer zurückziehbaren Zündelektrode in der Brennkammer, um die Zündung nur eines relativ kleinen Brenngasgemisches in der Brennkammer bei Inbetriebnahme der Vorrichtung zu gewährleisten.What is essential for the device according to the invention is therefore the formation of a combustion chamber in which the outlet nozzle for the fuel gases and the carrier gas stream is arranged so as to be adjustable in the longitudinal direction. The size of the combustion chamber is therefore variable and only the gases burned out in the combustion chamber reach the beam bundle channel under acceleration. Since the powder particles thus also only get into the combustion chamber, they are melted or melted there in an adapted manner and in this state reach the bundling channel. Furthermore, the arrangement of a retractable ignition electrode in the combustion chamber is essential in order to ensure the ignition of only a relatively small mixture of fuel gas in the combustion chamber when the device is started up.

Die erfindungsgemäße Vorrichtung wird nachfolgend anhand der zeichnerischen Darstellung von Ausführungsbeispielen näher erläutert.The device according to the invention is explained in more detail below with reference to the drawing of exemplary embodiments.

Es zeigt schematisch

  • Figur 1 im Schnitt die Vorrichtung einer Flammspritzpistolen/Strahlbündelungsdüsenkombination ;
  • Figur 2 im Schnitt die Vorrichtung in Form einer' Düsenstock/Strahibündelungsdüsenkombination ;
  • Figur 3 eine besondere Ausführungsform der Strahlbündelungsdüse ;
  • Figur 4 eine weitere besondere Ausführungsform der Strahlenbündelungsdüse zur Ausbildung einer Mantelströmung ;
  • Figur 5 eine bevorzugte Ausführungsform der Elektrodenausbildung :
  • Figur 6 ein Schaltschema für die Vorrichtung :
  • Figur 7 ein Funktionsdiagramm und
  • Figur 8 einen Schnitt durch einen Teil der Vorrichtung in einer weiteren Ausführungsform.
It shows schematically
  • Figure 1 shows in section the device of a flame spray gun / beam nozzle combination;
  • FIG. 2 shows the device in section in the form of a 'nozzle assembly / jet bundling nozzle combination;
  • FIG. 3 shows a special embodiment of the jet bundling nozzle;
  • FIG. 4 shows a further special embodiment of the beam focusing nozzle for forming a jacket flow;
  • FIG. 5 shows a preferred embodiment of the electrode formation:
  • FIG. 6 shows a circuit diagram for the device:
  • Figure 7 is a functional diagram and
  • Figure 8 shows a section through part of the device in a further embodiment.

Gemäß Fig. 1 sind die wesentlichen Teile der Vorrichtung die nur gestrichelt angedeutete Flammspritzpistole 6", ein die Brennkammer 2 enthaltender Adapter 3, die Strahlbündelungsdüse 1 und die Zündeinrichtung mit Elektrode 7. Die Flammspritzpistole 6" bedarf, da an sich bekannt, keiner näheren Erläuterung. Der Adapter 3 muß natürlich bezüglich seiner Aufnahmebohrung so bemessen sein, daß der Kopf 6' der Flammspritzpistole 6", in dem auch die Brennerdüse 5 sitzt, in den Adapter 3 eingesetzt werden kann, und zwar mit geeigneten Elementen in unterschiedlichen Stellungen fixierbar, um die Brennkammer 2 an die jeweiligen ― Erfordernisse anpassen zu können. Die Zündeinrichtung mit der Zündelektrode 7 ist dabei in bezug auf ihre Längsachse ebenfalls verstellbar angeordnet, so daß die geeignete Zünddistanz zur Düse 5 einstellbar ist und kurzzeitig für das Zünden ein Zündlichtbogen bzw. Zündfunke entstehen kann.According to FIG. 1, the essential parts of the device are the flame spray gun 6 ″, which is only indicated by dashed lines, an adapter 3 containing the combustion chamber 2, the beam focusing nozzle 1 and the ignition device with electrode 7. The flame spray gun 6 ″ requires no further explanation, as is known per se . The adapter 3 must of course be dimensioned with respect to its receiving bore so that the head 6 'of the flame spray gun 6 ", in which the burner nozzle 5 is seated, can be used in the adapter 3, specifically with suitable elements in different positions to fix the To be able to adapt combustion chamber 2 to the respective requirements, the ignition device with the ignition electrode 7 also being adjustable with respect to its longitudinal axis, so that the suitable ignition distance to the nozzle 5 can be set and an ignition arc or ignition spark can occur briefly for ignition .

Im vorliegenden Zusammenhang ist dabei die Zündeinrichtung gemäß Fig. 5 wie folgt ausgebildet : Die Elektrode 7 bildet den Anker einer Magnetspule 11, die bei Erregung die Elektrode 7 gegen die Wirkung einer Rückstellfeder 12 in Zündstellung (gestrichelt) zur Düse 5 bringt..In dieser Stellung ist von einem Endschalter 13 (Fig. 6) der Zündstrom eingeschaltet. Nach erfolgter Zündung, gekoppelt mit Stromabschaltung der Spule 11, wird die Elektrode 7 aus der Brennkammer 2 durch die Feder 12 zurückgestellt. Für den Zündvorgang ist wesentlich, daß die Zündung nicht etwa erst dann erfolgt, wenn die Brennkammer 2 gefüllt ist, sondern sofort zu Beginn des Einströmens eines zündfähigen Gasgemisches in die Brennkammer.In the present context, the ignition device according to FIG. 5 is designed as follows: The electrode 7 forms the armature of a magnetic coil 11 which, when excited, brings the electrode 7 into the ignition position (dashed line) to the nozzle 5 against the action of a return spring 12 The ignition current is switched on by a limit switch 13 (FIG. 6). After ignition, coupled with current cutoff of the coil 11, the electrode 7 is reset from the combustion chamber 2 by the spring 12. It is essential for the ignition process that the ignition does not take place only when the combustion chamber 2 is filled, but immediately at the beginning of the inflow of an ignitable gas mixture into the combustion chamber.

Die Strahlbündelungsdüse 1 einschließlich des Adapters 3 ist, wie aus Fig. 1 erkennbar, wassergekühlt ausgebildet, wobei die Kühlkanäle 14, 15 mit einer Verbindungsleitung 16 verbunden sind. Der Kühlmittelzuströmanschluß 17 für beide Kühlkanäle 14, 15 ist im Ansatzbereich der Strahlbündelungsdüse 18 zum Adapter 3 angeordnet, und für beide Kanäle 14, 15 ist ein gemeinsamer Kühlmittelabströmanschluß 19 vorgesehen.As can be seen from FIG. 1, the beam bundling nozzle 1 including the adapter 3 is water-cooled, the cooling channels 14, 15 being connected to a connecting line 16. The coolant inflow connection 17 for both cooling channels 14, 15 is arranged in the attachment area of the jet bundling nozzle 18 to the adapter 3, and a common coolant outflow connection 19 is provided for both channels 14, 15.

Zwecks Längenanpaßbarkeit kann gemäß Fig. 3 (dies gilt sowohl für die Ausführungsform nach Fig. 1 als auch für die gemäß Fig. 2) die Strahlbündelungsdüse 1 aus aneinander anschließbaren Einzelteilen 22 gebildet sein, die hinsichtlich der Kühlmitteldurchleitung durch Überbrükkungsleitungen 23 miteinander verbunden sind, sofern nicht jedes Einzelteil 22 mit separaten Zu- und Abströmansch.lüssen versehen ist.3 (this applies both to the embodiment according to FIG. 1 and for that according to FIG. 2), the beam bundling nozzle 1 can be formed from individual parts 22 which can be connected to one another and which are connected to one another with regard to the passage of coolant by bypass lines 23, provided that not every individual part 22 is provided with separate inlet and outlet connections.

Zur Ausbildung der vorerwähnten Mantelströmüng innerhalb der Strahlbündelungsdüse 1 sind am adapterseitigen Ende eine oder mehrere Gaszufuhröffnungen 21, wie in Fig. 4 schematisch dargestellt, vorgesehen. Ferner können solche Öffnungen 21' zusätzlich im Bereich der mündungsseitigen Hälfte der Strahlbündelungsdüse 1, bspw. im Strömungsschatten einer Abstufung 24 (rechts in Fig. 4) vorgesehen werden. Diese Ausführungsformen können auch bei der Vorrichtung nach Fig. 2 zur Anwendung kommen.To form the aforementioned jacket flow within the jet bundling nozzle 1, one or more gas supply openings 21 are provided at the end on the adapter side, as shown schematically in FIG. 4. In addition, such openings 21 'can additionally be provided in the region of the mouth-side half of the jet bundling nozzle 1, for example in the flow shadow of a gradation 24 (on the right in FIG. 4). These embodiments can also be used in the device according to FIG. 2.

Für die einwandfreie betriebssichere Inbetriebnahme und damit für die Funktionsfähigkeit des ganzen Gerätes überhaupt. ebenfalls für beide Ausführungsbeispiele (Fig. 1, 2) gültig, ist es wesentlich, daß der Brenngaszufuhrregler 8 und der Sauerstoff- bzw. Preßluftzufuhrregler 9 der Flammspritzpistole 5" einerseits und das Einschaltelement 10 für die Zündeinrichtung derart ausgebildet miteinander gekoppelt und angeordnet sind, daß Spülung der Strahlbündelungsdüse mit Sauerstoff oder Preßluft. Einschaltung der Zündeinrichtung und Einströmen des Brenngases zwangsläufig nacheinander bewirkbar sind. Dafür sind geeignete Regel- und Steuerelemente ohne weiteres verfügbar.For trouble-free, reliable commissioning and thus for the functionality of the entire device. also valid for both embodiments (Fig. 1, 2), it is essential that the fuel gas supply controller 8 and the oxygen or compressed air supply controller 9 of the flame spray gun 5 "on the one hand and the switch-on element 10 for the ignition device are designed and coupled with one another such that Flushing the jet bundle nozzle with oxygen or compressed air, switching on the ignition device and inflowing the fuel gas can inevitably be effected one after the other more available.

Das in bezug auf die Brennkammer 2 bewegliche bzw. einstellbare Teil (Flammspritzpistole 6" bzw. Düsenhalter 6 gemäß Fig. 2) ist vorteilhaft mit einer Markierung oder mit einem einstellbaren Anschlag versehen, um zu gewährleisten, daß für den Zündvorgang das betreffende Teil mit seiner Düse 5 in die richtige Zünddistanz zur Elektrode 7 gebracht wird.The part which is movable or adjustable with respect to the combustion chamber 2 (flame spray gun 6 "or nozzle holder 6 according to FIG. 2) is advantageously provided with a marking or with an adjustable stop in order to ensure that the part in question with its for the ignition process Nozzle 5 is brought into the correct ignition distance from electrode 7.

Die Zündeinrichtung bzw. die Elektrode 7 wird zweckmäßig im aufsteckseitigen Bereich 3' des die Brennkammer 2 enthaltenden Adapters 3 angeordnet, so daß auch bei größt eingestelltem Volumen der Brennkammer 2 die Durchgriffsöffnung in der Adapterwand für die Elektrode 7 abgedeckt wird, was in Rücksicht auf die hohen Temperaturen in der Brennkammer 2 vorteilhaft ist.The ignition device or the electrode 7 is expediently arranged in the plug-in region 3 'of the adapter 3 containing the combustion chamber 2, so that the access opening in the adapter wall for the electrode 7 is covered even when the volume of the combustion chamber 2 is set to the greatest extent, which is in consideration of the high temperatures in the combustion chamber 2 is advantageous.

Die Ausführungsform nach Fig. 2 unterscheidet sich von der nach Fig. 1 beschriebenen praktisch nur dadurch, daß hierbei anstelle der Spritzpistole ein entsprechend angepaßter Düsenstock bzw. Düsenhalter 6 vorgesehen und man damit nicht mehr an die Leistungsdaten der Flammspritzpistole 6" gebunden ist. Außerdem kann hiermit sowohl pulverförmig oder drahtförmig zugeführter Spritzwerkstoff verarbeitet werden. Nicht dargestellt sind bei der Flammspritzpistole der Pulvervorratsbehälter und beim Düsenhalter gemäß Fig. 2 die Förderelemente für den drahtförmigen Spritzwerkstoff, da solche Elemente allgemein bekannt sind. Der Düsenhalter 6 gemäß Fig. 2 kann selbstverständlich auch mit einem Anschluß für einen Pulvervorratsbehälter oder für eine Pulverzufuhrleitung ausgestattet sein. Entsprechende Teile dieser Ausführungsform nach Fig. 2 sind deshalb mit entsprechenden Bezugszeichen bezeichnet, die mit Strichindex versehen sind.The embodiment according to FIG. 2 differs from that described in FIG. 1 practically only in that instead of the spray gun a correspondingly adapted nozzle assembly or nozzle holder 6 is provided and one is no longer bound to the performance data of the flame spray gun 6 " 2, the conveying elements for the wire-shaped spray material are not shown for the flame spray gun and the nozzle holder according to FIG. 2, since such elements are generally known. The nozzle holder 6 according to FIG A connection for a powder storage container or for a powder supply line can be equipped with the corresponding parts of this embodiment according to Fig. 2 with corresponding reference numerals which are provided with a dash index.

In Fig. 8 sind die Flammspritzpistole bzw. der Düsenstock, die Elektrode und entsprechende Anschlußleitungen nicht dargestellt. Besonders deutlich hierbei ist die konvexe Gestaltung der Übergangskontur 4' von der Brennkammer 2 in den Strahlbündelungskanal 25 erkennbar, der sich konisch zur Ausmündung 26 hin etwas erweitert. Eine solche Erweiterung kann auch bei den Ausführungsformen nach Fig. 1, 2 vorgesehen werden. Außerdem ist bei der Ausführungsform nach Fig. 8 die Wand des Strahlbündelungskanales 25 als Formkörper 27 aus porösem, gasdurchlässigen Material ausgebildet. Der poröse Formkörper 27 ist dabei mit einem mit Druckgas beschickbaren Hohlraum 28 umgeben, dem das Druckgas durch einen Druckgasbeschickungsanschluß 29 zugeführt wird. Vorteilhaft ist dabei, wie dargestellt, der Hohlraum 28 vom Beschickungsanschluß 29 aus mit einem kleinerwerdenden Hohlraumvolumen versehen, um eine möglichst gleichmäßige Druckgasaustrittsverteilung durch das poröse Material des Formkörpers 27 hindurch über dessen ganze Länge zu gewährleisten. Der Formkörper 27 ist bspw. aus gesintertem AI203 oder Zr03 bzw. Mischformen davon gebildet. Da der Formkörper 27 auf seiner gesamten Fläche gasdurchlässig ist, bildet sich gewissermaßen ein sich ständig erneuerndes Gaspolster im Sinne der vorerwähnten Mantelströmung, wobei es durchaus möglich ist, im unmittelbaren Anschluß an die Überströmkontur 4' zusätzlich Öffnungen 21 anzuordnen. Beim durch den Anschluß 29 zugeführten Druckgas kann es sich durchaus auch um ein Brenngas handeln, das für eine zusätzliche Beschleunigung der gesamten Strömung im Strahlbündelungskanal 25 sorgt.8, the flame spray gun or the nozzle assembly, the electrode and corresponding connecting lines are not shown. The convex design of the transition contour 4 ′ from the combustion chamber 2 into the beam bundling channel 25 can be seen particularly clearly here, which widens somewhat conically toward the mouth 26. Such an extension can also be provided in the embodiments according to FIGS. 1, 2. In addition, in the embodiment according to FIG. 8, the wall of the beam focusing channel 25 is formed as a molded body 27 made of porous, gas-permeable material. The porous molded body 27 is surrounded by a cavity 28 which can be charged with compressed gas and to which the compressed gas is fed through a compressed gas charging connection 29. It is advantageous, as shown, to provide the cavity 28 with a decreasing cavity volume from the feed connection 29 in order to ensure the most uniform possible distribution of pressure gas outlet through the porous material of the molded body 27 over its entire length. The molded body 27 is, for example, formed of a sintered Al 2 0 3 or Zr0 3 or mixed forms thereof. Since the molded body 27 is gas-permeable over its entire surface, a constantly renewing gas cushion is formed in the sense of the aforementioned jacket flow, it being entirely possible to additionally arrange openings 21 in the immediate vicinity of the overflow contour 4 '. The compressed gas supplied through the connection 29 can also be a fuel gas which provides for an additional acceleration of the entire flow in the beam focusing channel 25.

Im Schaltschema gemäß Fig. 6 haben nur die großen Bezugszeichen 5, 7, 8. 9. 10, 11, 13 und X. Y direkten Bezug auf entsprechende Bezugszeichen in den Fig. 1-5. An die Vorrichtung selbst gehören von dieser Schaltung nur die Elemente 5, 7, 8, 9, 11, d. h. die, die sich unter der Strichpunktierten Linie im rechten Teil des Schaltbildes befinden.6, only the large reference numerals 5, 7, 8. 9. 10, 11, 13 and X. Y have direct reference to corresponding reference numerals in FIGS. 1-5. Of the circuit itself, only the elements 5, 7, 8, 9, 11, d. H. those that are under the dash-dotted line in the right part of the diagram.

Durch entsprechende anzug- bzw. abfallverzögerte Relais Ks, K2, K3, K4 und zugehörige Schaltungselemente wird an der Vorrichtung der notwendige Funktionsablauf gemäß Fig. 7 gewährleistet, wobei t3 die eigentliche Betriebsphase darstellt. Die dargestellten Kurven haben selbstverständlich nur qualitative Bedeutung. Bspw. verdeutlicht die Zündkurve, daß der Zündstrom nur im Zeitintervall t2 fließt, in dem erst das Brenngas zuzuströmen beginnt. Die Elektrodenkurve verdeutlicht, daß unmittelbar nach dem Intervall t2 die Elektrode zurückgezogen wird. Im Intervall t4, d. h. nach Abschaltung bei S3 der Steuerung fällt die Brenngaszufuhr sofort ab, wobei jedoch zwecks Spülung die Sauerstoffzufuhr noch ein wenig weiterlaufen kann.Corresponding relays K s , K 2 , K 3 , K 4 and corresponding circuit elements delayed on and off delay ensure the necessary functional sequence on the device according to FIG. 7, t 3 representing the actual operating phase. The curves shown are of course only of qualitative importance. E.g. illustrates the ignition curve that the ignition current only flows in the time interval t 2 , in which the fuel gas only begins to flow in. The electrode curve shows that the electrode is withdrawn immediately after the interval t 2 . In the interval t 4 , ie after the control unit has been switched off at S 3 , the fuel gas supply drops immediately, but the oxygen supply can continue to run a little for purging purposes.

Claims (14)

1. Apparatus for thermally spraying build-up welding materials, consisting of a coolable focussing nozzle (1) having a chamber (2) widened at the loading end for receiving means for adjustably supplying operating gases and build-up welding material, characterised in that the widened chamber comprises a combustion chamber (2) having a flow-accelerating transition contour (4') directed towards the mouth of the focussing nozzle, and a burner nozzle (5), or a nozzle holder (6) having a nozzle, is mounted in the combustion chamber (2), is axially movable relative to the mouth (4) of the focussing nozzle (1), and is loaded under differential pressure, there being an ignition electrode (7) mounted in the wall of the combustion chamber (2) which is alignable with the nozzle (5) and is provided with a switching element (10) which switches on the electrode (7) after the focussing nozzle (1) has been rinsed and before the combustion gas is fed in.
2. Apparatus as claimed in claim 1, characterised in that the flow-accelerating transition contour (4') from the combustion chamber (2) to the mouth (4) of the focussing nozzle (1) is of convex construction in relation to the longitudinal axis of the apparatus.
3. Apparatus as claimed in claim 1, characterised in that the nozzle holder (6) comprises a flame spray gun (6") know per se adjustably mounted in the bore of an adaptor (3) of the focussing nozzle (1).
4. Apparatus as claimed in claim 1, characterised in that the adjustable ignition electrode (7) comprises the armature of a magnetic coil (11) and is provided with a recoil spring (12) and an ignition current switching contact (13).
5. Apparatus as claimed in claim 1, characterised in that the ignition electrode (7) is mounted in the socket area (3') of the adaptor (3) of the focussing nozzle (1).
6. Apparatus as claimed in claim 1, characterised in that the wall of the combustion chamber (2) is provided with a cooling channel (14) connected to the cooling channel (15) of the focussing nozzle (1).
7. Apparatus as claimed in claim 6, characterised in that the coolant inlet (17) for the two cooling channels (14. 15) is arranged in the area of attachment (18) of the focussing nozzle (1) to the combustion chamber (2) and a coolant outlet (19) is provided which is common to both channels (14, 15).
8. Apparatus as claimed in claim 1, characterised in that a nozzle tube (20) is replacebaly mounted in the focussing nozzle (1) and extends over the entire internal length thereof.
9. Apparatus as claimed in claim 1, characterised in that one or more gas supply openings (21) are provided at the adaptor end of the focussing nozzle (1), to form a surface flow along the inner wall of the nozzle (1).
10. Apparatus as claimed in claim 1, characterised in that one or more gas supply openings (21') are provided in the half of the focussing nozzle (1) nearest the mouth of the focussing nozzle to form a surface flow along the inner wall of the nozzle (1 ).
11. Apparatus as claimed in claim 1, characterised in that the focussing nozzle (1) comprises a plurality of individual parts (22) which can be connected to one another.
12. Apparatus as claimed in claim 1, characterised in that the inner wall of the focussing nozzle (1) consists of a tubular moulding (27) of porous. gas-permeable material inserted in the nozzle body and surrounded by a cavity (28) chargeable with pressurised gas.
13. Apparatus as claimed in claim 12, characterised in that the cavity (28) decreases in size from the pressurised gas charging connection (29) to the end of the nozzle.
14. Apparatus as claimed in claim 1, characterised in that the switching element (10) for the electrode (7), the supply of combustion gas (8), and the oxygen or compressed air supply regulator (9) of the apparatus are coupled to one another and arranged in such a way that the rinsing of the focussing nozzle (1), the switching on of the ignition current and the inflow of combustion gas occur in that order.
EP84110175A 1983-08-30 1984-08-27 Apparatus for thermally spraying coating plasma Expired EP0135826B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84110175T ATE24420T1 (en) 1983-08-30 1984-08-27 DEVICE FOR THERMAL SPRAYING OF DEPOSITION WELDING MATERIALS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19833331216 DE3331216A1 (en) 1983-08-30 1983-08-30 DEVICE FOR THERMAL SPRAYING OF FOLDING WELDING MATERIALS
DE3331216 1983-08-30

Publications (2)

Publication Number Publication Date
EP0135826A1 EP0135826A1 (en) 1985-04-03
EP0135826B1 true EP0135826B1 (en) 1986-12-30

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EP84110175A Expired EP0135826B1 (en) 1983-08-30 1984-08-27 Apparatus for thermally spraying coating plasma

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US (1) US4711627A (en)
EP (1) EP0135826B1 (en)
JP (1) JPS60502243A (en)
AT (1) ATE24420T1 (en)
AU (1) AU573259B2 (en)
BR (1) BR8407043A (en)
CA (1) CA1215225A (en)
DE (2) DE3331216A1 (en)
IN (1) IN161699B (en)
MX (1) MX163708B (en)
SU (1) SU1493095A3 (en)
WO (1) WO1985000991A1 (en)

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Also Published As

Publication number Publication date
DE3461750D1 (en) 1987-02-05
AU573259B2 (en) 1988-06-02
SU1493095A3 (en) 1989-07-07
DE3331216A1 (en) 1985-03-14
ATE24420T1 (en) 1987-01-15
AU3315584A (en) 1985-03-29
IN161699B (en) 1988-01-16
JPH0416217B2 (en) 1992-03-23
US4711627A (en) 1987-12-08
EP0135826A1 (en) 1985-04-03
CA1215225A (en) 1986-12-16
WO1985000991A1 (en) 1985-03-14
JPS60502243A (en) 1985-12-26
BR8407043A (en) 1985-07-30
MX163708B (en) 1992-06-15

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