EP0103775A2 - Glow plug for internal combustion engines - Google Patents

Glow plug for internal combustion engines Download PDF

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Publication number
EP0103775A2
EP0103775A2 EP83108356A EP83108356A EP0103775A2 EP 0103775 A2 EP0103775 A2 EP 0103775A2 EP 83108356 A EP83108356 A EP 83108356A EP 83108356 A EP83108356 A EP 83108356A EP 0103775 A2 EP0103775 A2 EP 0103775A2
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EP
European Patent Office
Prior art keywords
ceramic carrier
head
sealing
glow plug
conductor
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.)
Granted
Application number
EP83108356A
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German (de)
French (fr)
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EP0103775B1 (en
EP0103775A3 (en
Inventor
Friedrich Dr. Esper
Thomas Dr. Frey
Günter Knoll
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Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0103775A2 publication Critical patent/EP0103775A2/en
Publication of EP0103775A3 publication Critical patent/EP0103775A3/en
Application granted granted Critical
Publication of EP0103775B1 publication Critical patent/EP0103775B1/en
Expired legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23Q—IGNITION; EXTINGUISHING-DEVICES
    • F23Q7/00—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs
    • F23Q7/001—Glowing plugs for internal-combustion engines

Definitions

  • the invention relates to a glow plug for internal combustion engines according to the preamble of the main claim.
  • a glow plug is already known (DE-OS 31 04 401), which has a rod-shaped or tubular ceramic body with a conductor-like heating element applied to its surface; the ceramic body of this glow plug is tightly sealed on the connection side and surrounded by a metal housing, with the fastening means of which the glow plug can be tightly installed in the cylinder head of internal combustion engines. Because of the limited space available in the cylinder head, the ceramic body can only have a relatively small outside diameter, as a result of which there is a risk of breaks in the ceramic body. Such a risk of breakage exists, in particular, in areas of grooves on the ceramic body and / or in the case of tubular ceramic bodies.
  • the glow plug according to the invention with the characterizing 'features of the main claim has the advantage that the ceramic body in spite of the same installation conditions Cylinder head can be equipped with a larger, more stable cross-section and is therefore no longer at risk of breakage and ensures greater operational reliability of the glow plug.
  • the measures listed in the subclaims allow advantageous developments and improvements of the glow plug specified in the main claim; It is particularly advantageous that the glow plug according to the invention can nevertheless be designed as a structural unit and, if appropriate, also be provided with a protective tube around the ceramic body and additionally even with overheating protection and / or a voltage limiter.
  • FIG. 1 shows a longitudinal section through an enlarged glow plug according to the invention and
  • FIG. 2 shows the enlarged head of the ceramic carrier with a preferred arrangement of the connecting conductors.
  • the glow plug 10 shown in FIGS. 1 and 2 essentially consists of three parts: a heating element 11, a connecting bolt 12 and a screw head 13.
  • the heating element 11 has a rod-shaped or tubular ceramic carrier 14, which is closed on the combustion chamber side by means of a dome-like bottom 15 and has a head 16 on its connection-side, open end section; this ceramic support 14 has in the area of its Bottom 15 has a thickness between 0.3 and 0.8 mm and consists of electrically insulating ceramic material or glass ceramic, but preferably of aluminum oxide.
  • the outer diameter of the ceramic carrier 14 is approximately 6 mm just below the sealing surface 21, approximately 5 mm above the dome-like base 15 and approximately 10 mm in the region of the head 16.
  • the interior 17 of this ceramic carrier 14 is preferably of slightly conical design, so that the core (not shown) located in this interior 17 can be easily removed during the production of the ceramic carrier 14; the diameter of the interior 17 is on average around 3 mm.
  • a ceramic carrier 14 with an interior 17 has the advantage of a lower heat capacity and better resistance to temperature changes compared to a solid ceramic carrier (not shown), but is not a condition for the claims with respect to the present subject matter.
  • the total length of the ceramic carrier 14 is usually - depending on the application - between 20 and 35 mm, but mostly around 28 mm.
  • the head 16 is provided on its connection-side end section with an annular groove 18, which is formed in the peripheral surface 19 of the head 16.
  • connection-side end face 20 preferably runs perpendicularly to the longitudinal axis of the ceramic carrier 14 (but it can also be frustoconical or the like if necessary), the transition of the head 16 serving as the sealing surface 21 to the end section of the ceramic carrier 14 on the combustion chamber side is frustoconical.
  • a layered heating element 22 is applied to the outside of the ceramic carrier 14, which preferably consists of a platinum-rhodium alloy with a ceramic portion (e.g. aluminum oxide), but can also be applied from another suitable electrically conductive material by means of known thick-film technology, and which has a configuration adapted to the respective application; in the preferred embodiment described, the heating element 22 is limited to the dome-shaped bottom 15 of the ceramic carrier 14 and runs as a meander.
  • the ceramic carrier 14 preferably consists of a platinum-rhodium alloy with a ceramic portion (e.g. aluminum oxide), but can also be applied from another suitable electrically conductive material by means of known thick-film technology, and which has a configuration adapted to the respective application; in the preferred embodiment described, the heating element 22 is limited to the dome-shaped bottom 15 of the ceramic carrier 14 and runs as a meander.
  • This heating element 22 is connected on the one hand to a first connection conductor 23 and on the other hand to a second connection conductor 24; while the first connecting conductor 23 is guided as a conductor path up to the connection-side end face 20 of the ceramic carrier 14 and forms a contact surface 25 there, the second connecting conductor 24 of the heating element 22 leads only up to the sealing surface 21 of the ceramic carrier 14 or slightly above.
  • a layered overheating protection 26 and / or a layered voltage limiter 27 can be switched on ( see Figure 2);
  • Such overheating protection 26 can, for example, be formed by a PTC resistor and be dimensioned such that the temperature of the heating element 22 can rise rapidly up to about 1000 ° C, but above this temperature limits the heating current due to its increased resistance value.
  • a PTC resistor serving as overheating protection 26 can consist in a known manner of a sintered nickel-ceramic mixture and is preferably arranged on the ceramic body 14 in the vicinity of the heating element 22.
  • a varistor is selected as the voltage limiter 27, which limits the heating voltage to approximately 8 V and consequently ensures that the glow temperature of the glow plug 10 is reached in approximately 2 seconds even when the charge condition of a 12 volt battery is poor.
  • the one as a voltage limiter 27 serving varistor can consist of zinc oxide in a known manner and is arranged on the ceramic carrier 14, preferably in colder zones of the ceramic carrier 14, for example in the vicinity of the ceramic carrier head 16. It should be mentioned that such overheating protection 26 or a voltage limiter 27 can also be installed in the (not shown) electrical lead to the glow plug 10.
  • the heating element 22 and its two connecting conductors 23 and 24 are covered by a thin protective layer 28; this protective layer 28, which consists of an electrically insulating, ceramic material (z. B.
  • FIG. 2 A preferred embodiment of the free end section of the second connecting conductor 24 is shown in FIG. 2:
  • the protective layer 28 is guided approximately into the region of the annular groove 18 of the ceramic carrier head 16, correspondingly high the second connecting conductor 24 on the ceramic carrier 14 attached and then the actual free end section of this second connecting conductor 24 is returned back to the sealing surface 21;
  • the protective layer 28 is usually a thickness of about 50 / have.
  • the position of the connecting conductors 23 and 24 on the ceramic carrier 14 corresponds more in practice to the embodiment according to FIG. 1 - they lie diametrically opposite one another on the ceramic carrier 14 - and not the position according to FIG. 2, the two connecting conductors 23 and 24 lying close together , which was done here only for the sake of illustration.
  • the basic structure of this radiator 11 corresponds essentially to the structure of the glow element of the glow plug for internal combustion engines described in German Utility Model 81 03 317 and can also be provided with the ceramic intermediate layer described therein or the heat-conducting layer also mentioned therein.
  • the meandering heating element 22 described it is also possible to use such configurations of heating elements as are additionally described in the utility model document mentioned, or also those which are arranged on part of the circumferential surface of the ceramic carrier 14.
  • the sealing surface 21 of the ceramic carrier head 16 is provided with an electrically conductive, metallic sealing element 29, which preferably consists of copper and also serves as a contact ring.
  • This sealing element 29 projects with a fastening means 30 (for example a flanged edge) into the region of the annular groove 18 and holds the sealing element 29 captively on the ceramic carrier 14.
  • this sealing element 29 is made of steel which is resistant to hot gas corrosion and is elongated in the manner of a sleeve on the combustion chamber side, so that it simultaneously forms a protective sleeve 31.
  • This protection sleeve 31 is arranged at a short distance around the radiator 11 and has openings 32 in its combustion chamber-side end section, which allow access of fuel vapor-air mixtures to the heating element 22, but on the other hand reliably prevents ceramic parts in the event of a breakage of the ceramic carrier 14 Combustion chamber of the internal combustion engine, not shown, can fall.
  • Such a protective sleeve 31 also assumes a protective function for the radiator 11 when assembling such glow plugs 10.
  • the sealing element 29 can also be provided with a protective sleeve (not shown) made of a material that burns during the operating temperature of the internal combustion engine (z. B. celluloid) can be combined, which then only takes over protective functions when mounting such glow plugs 10 or when installing such glow plugs 10 in the cylinder head.
  • a protective sleeve made of a material that burns during the operating temperature of the internal combustion engine (z. B. celluloid) can be combined, which then only takes over protective functions when mounting such glow plugs 10 or when installing such glow plugs 10 in the cylinder head.
  • a centering pin 33 of the metallic connecting bolt 12 projects into the connection-side area of the interior 17 of the ceramic carrier 14, which is followed on the connection side by a contact flange 34 which is integrally formed or fastened on the connection bolt 12.
  • This contact flange 34 lies on the contact surface 25 of the first connecting conductor 23 from the heating element 22.
  • a connection thread 35 is located on the connection-side end section of this connection bolt 12.
  • an annular electrical insulating element 36 is arranged, which consists of a pressure and temperature-resistant material (ceramic, plastic or the like), is guided with its central through hole 37 on the connecting bolt 12 and has an outer diameter, which on the one hand is larger than the diameter of the contact flange 34, but on the other hand has approximately the same diameter as the connection-side end face of the ceramic carrier 14.
  • This electrical insulation element 36 is preferably designed on the connection side as a pipe socket 38 which surrounds the connection bolt 12.
  • the screw head 13 rests with its end face 39 on the combustion chamber side.
  • This screw head 13 which consists of unalloyed steel, has an axial longitudinal bore 40 and with this at a distance comprises the connecting bolt 12 or receives the pipe socket 38 of the electrical insulating element 36; this screw head 13 is provided on its outside with an external thread 41 and a hexagon key 42 as fastening means for the installation of the glow plug 10 in the cylinder head bore 43 of the cylinder head 44 of the internal combustion engine shown in broken lines; the internal thread in the cylinder head bore 43 is designated 45.
  • the length of the screw head 13 is such that the connection thread 35 of the connection bolt 12 protrudes from the longitudinal bore 40 on the connection side.
  • the screw head 13 is provided with holding elements 46 which engage in the annular groove 18 of the radiator 11, but have so much play with respect to the radiator 11 that the screw head 13 can be rotated coaxially with respect to the radiator 11 and the connecting bolt 12.
  • This holding element 46 is preferably designed as a flanged edge, which can be formed on the screw head 13; Instead of an annular flanged edge, individual finger-like flaps serving this purpose can also be used (not shown), which are distributed over the circumference of the screw head end face 39.
  • the three main parts - radiator 11, connecting bolt 12, screw head 13 - form a structural part Unit that meets the tightest, known structural conditions on cylinder heads of internal combustion engines.
  • a frustoconical sealing seat 47 is incorporated, on which the radiator 11 of the glow plug 10 rests with its sealing element 29 and on which this sealing element 29 is pressed firmly and tightly due to the screwing force of the screw head 13; in special cases it is not necessary to insert a sealing element 29 between the sealing seat 47 of the cylinder head bore 43 and the sealing surface 21 of the ceramic carrier head 16.
  • the second connecting conductor 24 of the heating element 22, which ends in this area, is connected here directly or via the sealing element 29 to the cylinder head 44, which is electrically grounded, while the connecting bolt 12 via its connecting thread 35 and a connecting cable, not shown, to the positive pole of a power generator, not shown communicates.

Abstract

1. Glow plug (10) for internal-combustion engines, especially for internal-combustion engines without spark ignition, with a heating body (11) having a bar-shaped or tubular ceramic carrier (14) which, on the connection side, has a head (16) and on its surface is equipped with an electrical heating element (22) resembling a conductor track, from which a first electrical connecting conductor (24) resembling a conductor track is guided into an electrical contact region located in the sealing region of the heating body on the connection side, and from which, moreover, a second electrical connecting conductor (23) resembling a conductor track, covered on its top side with an electrically insulating, sealing protective layer in the sealing region on the connection side, is guided to the end face (20) of the ceramic carrier located on the connection side and is designed as a contact face (25), the end portion of the connecting bolt (12) standing up on the end contact face (25) of the ceramic carrier, characterized in that the head (16) of the ceramic carrier (14) has a sealing face (21) directed towards the combustion space and intended to form a seal with a corresponding sealing seat in the bore (43) of the cylinder head (44) of the internal-combustion engine, and in that rotatably arranged coaxially round the connecting bolt (12) is an essentially tubular screw head (13) which presses the connecting bolt (12) against the contact face (25) located on the end face (20) of the ceramic carrier (14) on the connection side, and which, moreover, is electrically insulated from the connecting bolt (12) by means of a ring-like, electrically insulating element (36) and also has fastening means (41, 42) for fastening the glow plug (10) and for pressing the sealing face (21) of the ceramic carrier against the corresponding sealing seat (47) in the internal-combustion engine.

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Glühkerze für Brennkraftmaschinen nach der Gattung des Hauptanspruchs. Es ist schon eine Glühkerze bekannt (DE-OS 31 04 401), die einen stab- bzw. rohrförmigen Keramikkörper mit auf dessen Oberfläche aufgebrachtem, leiterbahnartigem Heizelement besitzt; der Keramikkörper dieser Glühkerze ist anschlußseits fest und abgedichtet von einem Metallgehäuse umgeben, mit dessen Befestigungsmitteln die Glühkerze im Zylinderkopf von Brennkraftmaschinen dicht einzubauen ist. Aufgrund des geringen Platzangebotes im Zylinderkopf kann der Keramikkörper nur einen relativ kleinen Außendurchmesser haben, infolgedessen die Gefahr von Brüchen im Keramikkörper gegeben ist. Eine solche Bruchgefahr besteht insbesondere in Bereichen von Kehlen am Keramikkörper und/oder bei rohrförmigen Keramikkörpern.The invention relates to a glow plug for internal combustion engines according to the preamble of the main claim. A glow plug is already known (DE-OS 31 04 401), which has a rod-shaped or tubular ceramic body with a conductor-like heating element applied to its surface; the ceramic body of this glow plug is tightly sealed on the connection side and surrounded by a metal housing, with the fastening means of which the glow plug can be tightly installed in the cylinder head of internal combustion engines. Because of the limited space available in the cylinder head, the ceramic body can only have a relatively small outside diameter, as a result of which there is a risk of breaks in the ceramic body. Such a risk of breakage exists, in particular, in areas of grooves on the ceramic body and / or in the case of tubular ceramic bodies.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Glühkerze mit den kennzeichnenden 'Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, daß der Keramikkörper trotz gleicher Einbaubedingungen im Zylinderkopf mit einem größeren, tragfähigeren Querschnitt ausgestattet werden kann und demzufolge nicht mehr derart bruchgefährdet ist und eine größere Betriebssicherheit der Glühkerze gewährleistet.The glow plug according to the invention with the characterizing 'features of the main claim has the advantage that the ceramic body in spite of the same installation conditions Cylinder head can be equipped with a larger, more stable cross-section and is therefore no longer at risk of breakage and ensures greater operational reliability of the glow plug.

Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Hauptanspruch angegebenen Glühkerze möglich; besonders vorteilhaft ist es, daß die erfindungsgemäße Glühkerze dennoch als Baueinheit ausgebildet und gegebenenfalls auch mit einem Schutzrohr um den Keramikkörper und zusätzlich sogar mit einem Überhitzungsschutz und/oder einem Spannungsbegrenzer versehen werden kann.The measures listed in the subclaims allow advantageous developments and improvements of the glow plug specified in the main claim; It is particularly advantageous that the glow plug according to the invention can nevertheless be designed as a structural unit and, if appropriate, also be provided with a protective tube around the ceramic body and additionally even with overheating protection and / or a voltage limiter.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 einen Längsschnitt durch eine vergrößert dargestellte Glühkerze nach der Erfindung und Figur 2 den vergrößert dargestellten Kopf des Keramikträgers mit einer bevorzugten Anordnung der Anschlußleiter.An embodiment of the invention is shown in the drawing and explained in more detail in the following description. 1 shows a longitudinal section through an enlarged glow plug according to the invention and FIG. 2 shows the enlarged head of the ceramic carrier with a preferred arrangement of the connecting conductors.

Beschreibung des AusführungsbeispielsDescription of the embodiment

Die in den Figuren 1 und 2 dargestellte Glühkerze 10 besteht im wesentlichen aus drei Teilen: einem Heizkörper 11, einem Anschlußbolzen 12 und einem Schraubkopf 13.The glow plug 10 shown in FIGS. 1 and 2 essentially consists of three parts: a heating element 11, a connecting bolt 12 and a screw head 13.

Der Heizkörper 11 besitzt einen stab- bzw. rohrförmigen Keramikträger 14, welcher brennraumseits mittels eines kuppenartigen Bodens 15 verschlossen ist und an seinem anschlußseitigen, offenen Endabschnitt einen Kopf 16 aufweist; dieser Keramikträger 14 hat im Bereich seines Bodens 15 eine Dicke zwischen 0,3 und 0,8 mm und besteht aus elektrisch isolierendem Keramikmaterial oder Glaskeramik, vorzugsweise jedoch aus Aluminiumoxid. Der Außendurchmesser des Keramikträgers 14 beträgt dicht unterhalb der Dichtfläche 21 etwa 6 mm, oberhalb des kuppenartigen Bodens 15 etwa 5 mm und im Bereich des Kopfes 16 etwa 10 mm. Der Innenraum 17 dieses Keramikträgers 14 ist vorzugsweise geringfügig konisch gestaltet, damit bei der Herstellung des Keramikträgers 14 der in diesem Innenraum 17 befindliche Kern (nicht dargestellt) problemlos entfernt werden kann; der Durchmesser des Innenraumes 17 beträgt im Mittel um 3 mm. Ein Keramikträger 14 mit einem Innenraum 17 hat gegenüber einem massiven Keramikträger (nicht dargestellt) den Vorteil einer geringeren Wärmekapazität und besserer Temperaturwechselbeständigkeit, ist jedoch keine Bedingung für die Ansprüche bezüglich des vorliegenden Erfindungsgegenstandes. Die Gesamtlänge des Keramikträgers 14 liegt üblicherweise - je nach Anwendungsfall - zwischen 20 und 35 mm, zumeist jedoch um 28 mm. Der Kopf 16 ist in bevorzugter Ausführungsform an seinem anschlußseitigen Endabschnitt mit einer Ringnut 18 versehen, welche in die Umfangsfläche 19 des Kopfes 16 mit eingeformt ist. Während die anschlußseitige Stirnfläche 20 in bevorzugter Weise senkrecht zur Längsachse des Keramikträgers 14 verläuft (sie kann im Bedarfsfalle aber auch kegelstumpfförmig o.ä. ausgebildet sein), verläuft der als Dichtfläche 21 dienende Übergang des Kopfes 16 zum brennraumseitigen Endabschnitt des Keramikträgers 14 kegelstumpfförmig.The heating element 11 has a rod-shaped or tubular ceramic carrier 14, which is closed on the combustion chamber side by means of a dome-like bottom 15 and has a head 16 on its connection-side, open end section; this ceramic support 14 has in the area of its Bottom 15 has a thickness between 0.3 and 0.8 mm and consists of electrically insulating ceramic material or glass ceramic, but preferably of aluminum oxide. The outer diameter of the ceramic carrier 14 is approximately 6 mm just below the sealing surface 21, approximately 5 mm above the dome-like base 15 and approximately 10 mm in the region of the head 16. The interior 17 of this ceramic carrier 14 is preferably of slightly conical design, so that the core (not shown) located in this interior 17 can be easily removed during the production of the ceramic carrier 14; the diameter of the interior 17 is on average around 3 mm. A ceramic carrier 14 with an interior 17 has the advantage of a lower heat capacity and better resistance to temperature changes compared to a solid ceramic carrier (not shown), but is not a condition for the claims with respect to the present subject matter. The total length of the ceramic carrier 14 is usually - depending on the application - between 20 and 35 mm, but mostly around 28 mm. In a preferred embodiment, the head 16 is provided on its connection-side end section with an annular groove 18, which is formed in the peripheral surface 19 of the head 16. While the connection-side end face 20 preferably runs perpendicularly to the longitudinal axis of the ceramic carrier 14 (but it can also be frustoconical or the like if necessary), the transition of the head 16 serving as the sealing surface 21 to the end section of the ceramic carrier 14 on the combustion chamber side is frustoconical.

Auf der Außenseite des Keramikträgers 14 ist ein schichtförmiges Heizelement 22 aufgebracht, welches bevorzugt aus einer Platin-Rhodium-Legierung mit keramischem Anteil (z. B. Aluminiumoxid) besteht, aber auch aus einem anderen geeigneten elektrisch leitendem Material mittels bekannter Dickschichttechnik aufgebracht sein kann, und welches eine dem jeweiligen Anwendungszweck angepaßte Konfiguration aufweist; bei der beschriebenen, bevorzugten Ausführungsform ist das Heizelement 22 auf den kuppenförmigen Boden 15 des Keramikträgers 14 beschränkt und verläuft als Mäander. Dieses Heizelement 22 ist einerseits an einen ersten Anschlußleiter 23 und andererseits an einen zweiten Anschlußleiter 24 angeschlossen; während der erste Anschlußleiter 23 als Leiterbahn bis hinauf zur anschlußseitigen Stirnfläche 20 des Keramikträgers 14 geführt ist und dort eine Kontaktfläche 25 bildet, führt der zweite Anschlußleiter 24 des Heizelementes 22 nur bis auf die Dichtfläche 21 des Keramikträgers 14 bzw. geringfügig darüber hinweg. In den ersten Anschlußleiter 23 und/oder den zweiten Anschlußleiter 24, welche in bevorzugter Weise aus einer Mischung von Platin und Aluminiumoxid bestehen und mittels Dickschichttechnik auf den Keramikträger 14 aufgebracht sind, kann ein schichtförmiger Überhitzungsschutz 26 und/oder ein schichtförmiger Spannungsbegrenzer 27 eingeschaltet sein (siehe Figur 2); ein solcher Überhitzungsschutz 26 kann beispielsweise durch einen PTC-Widerstand gebildet und so bemessen sein, daß der bis etwa 1 000 C einen schnellen Temperaturanstieg des Heizelementes 22 erlaubt, oberhalb dieser Temperatur jedoch infolge seines erhöhten Widerstandswertes den Heizstrom begrenzt. Ein solcher als Überhitzungsschutz 26 dienender PTC-Widerstand kann in bekannter Weise aus einem gesinterten Nickel-Keramik-Gemisch bestehen und wird auf dem Keramikkörper 14 bevorzugt in der Nähe des Heizelements 22 angeordnet. Als Spannungsbegrenzer 27 wird ein Varistor gewählt, welcher die Heizspannung auf etwa 8 V begrenzt und demzufolge gewährleistet, daß auch bei schlechtem Ladezustand einer 12-Volt-Batterie die Glühtemperatur der Glühkerze 10 in etwa 2 Sekunden erreicht wird. Der als Spannungsbegrenzer 27 dienende Varistor kann in bekannter Weise aus Zinkoxid bestehen und ist auf dem Keramikträger 14 bevorzugt in kälteren Zonen des Keramikträgers 14, z.B. in der Nähe des Keramikträger-Kopfes 16 angeordnet. Es sei erwähnt, daß ein solcher Überhitzungsschutz 26 bzw. ein Spannungsbegrenzer 27 auch in der (nicht dargestellten) elektrischen Zuleitung zur Glühkerze 10 installiert sein kann. Das Heizelement 22 und seine beiden Anschlußleiter 23 und 24 sind mittels einer dünnen Schutzschicht 28 abgedeckt; diese Schutzschicht 28, die aus einem elektrisch isolierenden, keramischen Material (z. B. Aluminiumoxid, Magnesiumspinell) besteht und die bedeckten elektrischen Leiter (22, 23, 24, 26, 27) gegen Abrasion, Korrosion und Kurzschluß schützt, überdeckt jedoch nicht die Kontaktfläche 25 auf der anschlußseitigen Stirnfläche 20 des Keramikträgers 14 und auch nicht den im Bereich der Dichtfläche 21 des Keramikträgers 14 befindlichen Endabschnitts des zweiten Anschlußleiters 24.A layered heating element 22 is applied to the outside of the ceramic carrier 14, which preferably consists of a platinum-rhodium alloy with a ceramic portion (e.g. aluminum oxide), but can also be applied from another suitable electrically conductive material by means of known thick-film technology, and which has a configuration adapted to the respective application; in the preferred embodiment described, the heating element 22 is limited to the dome-shaped bottom 15 of the ceramic carrier 14 and runs as a meander. This heating element 22 is connected on the one hand to a first connection conductor 23 and on the other hand to a second connection conductor 24; while the first connecting conductor 23 is guided as a conductor path up to the connection-side end face 20 of the ceramic carrier 14 and forms a contact surface 25 there, the second connecting conductor 24 of the heating element 22 leads only up to the sealing surface 21 of the ceramic carrier 14 or slightly above. In the first connection conductor 23 and / or the second connection conductor 24, which preferably consist of a mixture of platinum and aluminum oxide and are applied to the ceramic carrier 14 by means of thick-film technology, a layered overheating protection 26 and / or a layered voltage limiter 27 can be switched on ( see Figure 2); Such overheating protection 26 can, for example, be formed by a PTC resistor and be dimensioned such that the temperature of the heating element 22 can rise rapidly up to about 1000 ° C, but above this temperature limits the heating current due to its increased resistance value. Such a PTC resistor serving as overheating protection 26 can consist in a known manner of a sintered nickel-ceramic mixture and is preferably arranged on the ceramic body 14 in the vicinity of the heating element 22. A varistor is selected as the voltage limiter 27, which limits the heating voltage to approximately 8 V and consequently ensures that the glow temperature of the glow plug 10 is reached in approximately 2 seconds even when the charge condition of a 12 volt battery is poor. The one as a voltage limiter 27 serving varistor can consist of zinc oxide in a known manner and is arranged on the ceramic carrier 14, preferably in colder zones of the ceramic carrier 14, for example in the vicinity of the ceramic carrier head 16. It should be mentioned that such overheating protection 26 or a voltage limiter 27 can also be installed in the (not shown) electrical lead to the glow plug 10. The heating element 22 and its two connecting conductors 23 and 24 are covered by a thin protective layer 28; this protective layer 28, which consists of an electrically insulating, ceramic material (z. B. aluminum oxide, magnesium spinel) and protects the covered electrical conductors (22, 23, 24, 26, 27) against abrasion, corrosion and short circuit, but does not cover the Contact surface 25 on the connection-side end surface 20 of the ceramic carrier 14 and also not the end section of the second connection conductor 24 located in the area of the sealing surface 21 of the ceramic carrier 14.

Aus der Figur 2 ist eine bevorzugte Ausführungsform des freien Endabschnitts vom zweiten Anschlußleiter 24 dargestellt: Bei dieser Ausführungsform ist die Schutzschicht 28 bis etwa in den Bereich der Ringnut 18 des Keramikträger-Kopfes 16 geführt, entsprechend hoch zunächst auch der zweite Anschlußleiter 24 auf dem Keramikträger 14 angebracht und anschließend ist der eigentliche freie Endabschnitt dieses zweiten Anschlußleiters 24 wieder zurück bis auf die Dichtfläche 21 zurückgeführt; infolge dieser Gestaltung des freien Endabschnitts vom zweiten Anschlußleiters 24 werden unnötig hohe mechanische Spannungen vermieden, welche durch das partielle Abdecken der Anschlußleiter 23 und 24 mit der relativ dicken, dichten Schutzschicht 28 bewirkt werden können. Die Schutzschicht 28 wird üblicherweise eine Dicke von etwa 50 /um haben. Die Lage der Anschlußleiter 23 und 24 auf dem Keramikträger 14 entspricht in der Praxis mehr der Ausführung nach Figur 1 - sie liegen sich auf dem Keramikträger 14 also diametral gegenüber - und nicht der Lage gemäß Figur 2, wobei die beiden Anschlußleiter 23 und 24 dicht beeinanderliegen, was hier nur aus Gründen der zeichnerischen Darstellung erfolgte.A preferred embodiment of the free end section of the second connecting conductor 24 is shown in FIG. 2: In this embodiment, the protective layer 28 is guided approximately into the region of the annular groove 18 of the ceramic carrier head 16, correspondingly high the second connecting conductor 24 on the ceramic carrier 14 attached and then the actual free end section of this second connecting conductor 24 is returned back to the sealing surface 21; As a result of this design of the free end section of the second connecting conductor 24, unnecessarily high mechanical stresses are avoided, which can be caused by partially covering the connecting conductors 23 and 24 with the relatively thick, dense protective layer 28. The protective layer 28 is usually a thickness of about 50 / have. The position of the connecting conductors 23 and 24 on the ceramic carrier 14 corresponds more in practice to the embodiment according to FIG. 1 - they lie diametrically opposite one another on the ceramic carrier 14 - and not the position according to FIG. 2, the two connecting conductors 23 and 24 lying close together , which was done here only for the sake of illustration.

Der prinzipielle Aufbau dieses Heizkörpers 11 entspricht im wesentlichen dem Aufbau des Glühkörpers der in der deutschen Gebrauchsmusterschrift 81 03 317 beschriebenen Glühkerze für Brennkraftmaschinen und kann auch mit der darin beschriebenen Keramik-Zwischenschicht bzw. der ebenfalls darin erwähnten Wärmeleitschicht versehen sein. Anstelle des beschriebenen mäanderförmigen Heizelementes 22 können auch solche Konfigurationen von Heizelementen Verwendung finden, wie sie zusätzlich in der genannten Gebrauchsmusterschrift beschrieben sind, oder auch solche, die auf einem Teil der Umfangsfläche des Keramikträgers 14 angeordnet sind.The basic structure of this radiator 11 corresponds essentially to the structure of the glow element of the glow plug for internal combustion engines described in German Utility Model 81 03 317 and can also be provided with the ceramic intermediate layer described therein or the heat-conducting layer also mentioned therein. Instead of the meandering heating element 22 described, it is also possible to use such configurations of heating elements as are additionally described in the utility model document mentioned, or also those which are arranged on part of the circumferential surface of the ceramic carrier 14.

Bei einer bevorzugten Ausführungsform dieser Glühkerze 10 ist die Dichtfläche 21 des Keramikträger-Kopfes 16 mit einem elektrisch leitenden, metallischen Dichtelement 29 versehen, welcher bevorzugt aus Kupfer besteht und auch .als Kontaktring dient. Dieses Dichtelement 29 ragt mit einem Befestigungsmittel 30 (z. B. Bördelrand) in den Bereich der Ringnut 18 und hält das Dichtelement 29 unverlierbar auf dem Keramikträger 14 fest.In a preferred embodiment of this glow plug 10, the sealing surface 21 of the ceramic carrier head 16 is provided with an electrically conductive, metallic sealing element 29, which preferably consists of copper and also serves as a contact ring. This sealing element 29 projects with a fastening means 30 (for example a flanged edge) into the region of the annular groove 18 and holds the sealing element 29 captively on the ceramic carrier 14.

Gemäß der in Figur 1 dargestellten Ausführungsform der Glühkerze 10 ist dieses Dichtelement 29 aus einem gegenüber Heißgaskorrosion beständigem Stahl hergestellt und brennraumseits derart hülsenförmig verlängert, so daß es gleichzeitig eine Schutzhülse 31 bildet. Diese Schutzhülse 31 ist mit geringem Abstand um den Heizkörper 11 angeordnet und besitzt in seinem brennraumseitigen Endabschnitt Durchbrüche 32, welche den Zugang von Kraftstoffdampf-Luft-Gemischen zum Heizelement 22 erlauben, andererseits aber sicher verhindert, daß bei einem eventuellen Bruch des Keramikträgers 14 Keramikteile in den Brennraum der nicht dargestellten Brennkraftmaschine fallen können. Eine solche Schutzhülse 31 übernimmt bei der Montage derartiger Glühkerzen 10 außerdem eine Schutzfunktion für den Heizkörper 11. - Anstelle einer solchen aus Stahl bestehenden Schutzhülse 31 kann das Dichtelement 29 aber auch mit einer (nicht dargestellten) Schutzhülse aus einem während der Betriebstemperatur der Brennkraftmaschine verbrennendem Material (z. B. Zelluloid) kombiniert sein, welche dann aber nur Schutzfunktionen anläßlich der Montage derartiger Glühkerzen 10 oder beim Einbau derartiger Glühkerzen 10 in den Zylinderkopf übernimmt.According to the embodiment of the glow plug 10 shown in FIG. 1, this sealing element 29 is made of steel which is resistant to hot gas corrosion and is elongated in the manner of a sleeve on the combustion chamber side, so that it simultaneously forms a protective sleeve 31. This protection sleeve 31 is arranged at a short distance around the radiator 11 and has openings 32 in its combustion chamber-side end section, which allow access of fuel vapor-air mixtures to the heating element 22, but on the other hand reliably prevents ceramic parts in the event of a breakage of the ceramic carrier 14 Combustion chamber of the internal combustion engine, not shown, can fall. Such a protective sleeve 31 also assumes a protective function for the radiator 11 when assembling such glow plugs 10. Instead of such a protective sleeve 31 made of steel, the sealing element 29 can also be provided with a protective sleeve (not shown) made of a material that burns during the operating temperature of the internal combustion engine (z. B. celluloid) can be combined, which then only takes over protective functions when mounting such glow plugs 10 or when installing such glow plugs 10 in the cylinder head.

In den anschlußseitigen Bereich des Innenraums 17 des Keramikträgers 14 ragt ein Zentrierzapfen 33 des metallischen Anschlußbolzens 12 hinein, welchem sich anschlußseits ein an den Anschlußbolzen 12 angeformter bzw. befestigter Kontaktflansch 34 anschließt. Dieser Kontaktflansch 34 liegt auf der Kontaktfläche 25 des ersten Anschlußleiters 23 vom Heizelement 22 auf. Am anschlußseitigen Endabschnitt dieses Anschlußbolzens 12 befindet sich ein Anschlußgewinde 35.A centering pin 33 of the metallic connecting bolt 12 projects into the connection-side area of the interior 17 of the ceramic carrier 14, which is followed on the connection side by a contact flange 34 which is integrally formed or fastened on the connection bolt 12. This contact flange 34 lies on the contact surface 25 of the first connecting conductor 23 from the heating element 22. A connection thread 35 is located on the connection-side end section of this connection bolt 12.

Auf der anschlußseitigen Seite dieses Kontaktflansches 34 ist ein ringförmiges Elektroisolierelement 36 angeordnet, welches aus einem druck- und temperaturbeständigem Material (Keramik, Kunststoff oder ähnliches) besteht, mit seinem zentralen Durchgangsloch 37 auf dem Anschlußbolzen 12 geführt ist und einen Außendurchmesser besitzt, welcher einerseits größer ist als der Durchmesser des Kontaktflansches 34, andererseits aber etwa einen gleichen Durchmesser hat wie die anschlußseitige Stirnfläche des Keramikträgers 14. Dieses Elektroisolierelement 36 ist in bevorzugter Weise anschlußseitig als Rohrstutzen 38 gestaltet, welcher den Anschlußbolzen 12 umgibt.On the connection side of this contact flange 34, an annular electrical insulating element 36 is arranged, which consists of a pressure and temperature-resistant material (ceramic, plastic or the like), is guided with its central through hole 37 on the connecting bolt 12 and has an outer diameter, which on the one hand is larger than the diameter of the contact flange 34, but on the other hand has approximately the same diameter as the connection-side end face of the ceramic carrier 14. This electrical insulation element 36 is preferably designed on the connection side as a pipe socket 38 which surrounds the connection bolt 12.

Anschlußseits auf diesem Elektroisolierelement 36 liegt der Schraubkopf 13 mit seiner brennraumseitigen Stirnfläche 39 auf. Dieser Schraubkopf 13, welcher aus unlegiertem Stahl besteht, hat eine axiale Längsbohrung 40 und umfaßt mit dieser mit Abstand den Anschlußbolzen 12 bzw. nimmt den Rohrstutzen 38 des Elektroisolierelementes 36 auf; dieser Schraubkopf 13 ist auf seiner Außenseite mit einem Außengewinde 41 und einem Schlüsselsechskant 42 als Befestigungsmitteln für den Einbau der Glühkerze 10 in die strichpunktiert dargestellte Zylinderkopf-Bohrung 43 des Zylinderkopfes 44 der Brennkraftmaschine versehen; das Innengewinde in der Zylinderkopf-Bohrung 43 ist mit 45 bezeichnet. Der Schraubkopf 13 ist in der Länge so bemessen, daß anschlußseits das Anschlußgewinde 35 des Anschlußbolzens 12 aus der Längsbohrung 40 herausragt. Brennraumseits ist der Schraubkopf 13 mit Halteelementen 46 versehen, welche in die Ringnut 18 des Heizkörpers 11 eingreifen, jedoch so viel Spiel gegenüber dem Heizkörper 11 haben, daß der Schraubkopf 13 gegenüber dem Heizkörper 11 und dem Anschlußbolzen 12 koaxial verdreht werden kann. Dieses Halteelement 46 ist bevorzugt als Bördelrand ausgebildet, welcher am Schraubkopf 13 mit angeformt sein kann; anstelle eines ringförmigen Bördelrandes können aber auch einzelne fingerartige, diesen Zweck erfüllende Lappen dienen (nicht dargestellt), welche auf dem Umfang der Schraubkopf-Stirnfläche 39 verteilt sind. Infölge dieses Halteelements 46 bilden die drei Hauptteile - Heizkörper 11, Anschlußbolzen 12, Schraubkopf 13 - eine bauliche Einheit, die engsten, bekannten baulichen Bedingungen an Zylinderköpfen von Brennkraftmaschinen gerecht wird.On the connection side on this electrical insulating element 36, the screw head 13 rests with its end face 39 on the combustion chamber side. This screw head 13, which consists of unalloyed steel, has an axial longitudinal bore 40 and with this at a distance comprises the connecting bolt 12 or receives the pipe socket 38 of the electrical insulating element 36; this screw head 13 is provided on its outside with an external thread 41 and a hexagon key 42 as fastening means for the installation of the glow plug 10 in the cylinder head bore 43 of the cylinder head 44 of the internal combustion engine shown in broken lines; the internal thread in the cylinder head bore 43 is designated 45. The length of the screw head 13 is such that the connection thread 35 of the connection bolt 12 protrudes from the longitudinal bore 40 on the connection side. Combustion chamber side, the screw head 13 is provided with holding elements 46 which engage in the annular groove 18 of the radiator 11, but have so much play with respect to the radiator 11 that the screw head 13 can be rotated coaxially with respect to the radiator 11 and the connecting bolt 12. This holding element 46 is preferably designed as a flanged edge, which can be formed on the screw head 13; Instead of an annular flanged edge, individual finger-like flaps serving this purpose can also be used (not shown), which are distributed over the circumference of the screw head end face 39. As a result of this holding element 46, the three main parts - radiator 11, connecting bolt 12, screw head 13 - form a structural part Unit that meets the tightest, known structural conditions on cylinder heads of internal combustion engines.

In der Zylinderkopf-Bohrung 43 ist ein kegelstumpfförmiger Dichtsitz 47 eingearbeitet, auf welchem der Heizkörper 11 der Glühkerze 10 mit seinem Dichtelement 29 aufliegt und und auf welchen dieses Dichtelement 29 infolge der Einschraubkraft des Schraubkopfes 13 fest und dicht gedrückt wird; in Sonderfällen kann auf das Einfügen eines Dichtelementes 29 zwischen den Dichtsitz 47 der Zylinderkopf-Bohrung 43 und der Dichtfläche 21 des Keramikträger-Kopfes 16 verzichtet werden. Der in diesem Bereich endende zweite Anschlußleiter 24 des Heizelementes 22 steht hier direkt oder über das Dichtelement 29 mit dem elektrisch an Masse liegenden Zylinderkopf 44 in Verbindung, während der Anschlußbolzen 12 über sein Anschlußgewinde 35 und einem nicht dargestellten Anschlußkabel mit dem Pluspol eines nicht dargestellten Stromerzeugers in Verbindung steht.In the cylinder head bore 43, a frustoconical sealing seat 47 is incorporated, on which the radiator 11 of the glow plug 10 rests with its sealing element 29 and on which this sealing element 29 is pressed firmly and tightly due to the screwing force of the screw head 13; in special cases it is not necessary to insert a sealing element 29 between the sealing seat 47 of the cylinder head bore 43 and the sealing surface 21 of the ceramic carrier head 16. The second connecting conductor 24 of the heating element 22, which ends in this area, is connected here directly or via the sealing element 29 to the cylinder head 44, which is electrically grounded, while the connecting bolt 12 via its connecting thread 35 and a connecting cable, not shown, to the positive pole of a power generator, not shown communicates.

Claims (6)

1. Glühkerze für Brennkraftmaschinen, insbesondere für Brennkraftmaschinen ohne Fremdzündung, mit einem Heizkörper, der einen stab- bzw. rohrförmigen Keramikträger besitzt, welcher anschlußseits einen Kopf hat und auf seiner Oberfläche mit einem leiterbahnartigen, elektrischen Heizelement versehen ist, von dem aus ein leiterbahnartiger, elektrischer Anschlußleiter auf die anschlußseitige Stirnfläche des Keramikträgers geführt und als Kontaktfläche ausgebildet ist, wobei vorzugsweise das Heizelement und gegebenenfalls auch ein Teil der Anschlußleiter mittels einer elektrisch isolierenden, dichten Schutzschicht bedeckt ist und wobei auf der stirnseitigen Kontaktfläche des Keramikträgers der Endabschnitt eines Anschlußbolzens aufsteht, dadurch gekennzeichnet, daß der Kopf (16) des Keramikträgers (14) eine Dichtfläche (21) besitzt, mit der er direkt oder unter Einfügung eines Dichtelementes (29) auf einem entsprechenden Dichtsitz (47) in der Bohrung (43) des Zylinderkopfes (44) einer Brennkraftmaschine aufliegt, und daß koaxial um den Anschlußbolzen (12) herum ein im wesentlichen rohrförmiger Schraubkopf (13) drehbar angeordnet ist, welcher den Anschlußbolzen (12) gegen die auf der anschlußseitigen Stirnfläche (20) des Keramikträgers (14) befindliche Kontaktfläche (25) drückt, mittels ringartigem Elektroisolierelement (36) gegenüber dem Anschlußbolzen (12) elektrisch isoliert ist und Befestigungsmittel (41, 42) besitzt, mittels welchen er in der Brennkraftmaschine zu befestigen ist und die Dichtfläche (21) des Keramikträgers (14) fest und abdichtend gegen den entsprechenden Dichtsitz (47) in der Brennkraftmaschine zu drücken vermag.1. glow plug for internal combustion engines, in particular for internal combustion engines without spark ignition, with a radiator which has a rod-shaped or tubular ceramic carrier which has a head on the connection side and is provided on its surface with an electrical conductor-like heating element, from which a conductor-like, electrical connection conductor is guided onto the connection-side end face of the ceramic carrier and is designed as a contact surface, whereby preferably the heating element and possibly also a part of the connection conductor is covered by an electrically insulating, dense protective layer and wherein the end section of a connection bolt stands on the end-side contact surface of the ceramic carrier characterized in that the head (16) of the ceramic carrier (14) has a sealing surface (21) with which it can be directly or with the insertion of a sealing element (29) on a corresponding sealing seat (47) in the bore (43) of the cylinder head (44) a focal machine, and that a substantially tubular screw head (13) is rotatably arranged coaxially around the connecting bolt (12), said screw head (13) against the contact surface (25) located on the connection-side end face (20) of the ceramic carrier (14) presses, is electrically insulated from the connecting bolt (12) by means of a ring-shaped electrical insulating element (36) and has fastening means (41, 42), by means of which it is to be fastened in the internal combustion engine and is able to press the sealing surface (21) of the ceramic carrier (14) firmly and sealingly against the corresponding sealing seat (47) in the internal combustion engine. 2. Glühkerze nach Anspruch 1, dadurch gekennzeichnet, daß der Kopf (16) des Keramikträgers (14) anschlußseits auf seiner Umfangsfläche (19) eine Ringnut (18) hat, in welche ein am brennraumseitigen Endabschnitt des Schraubkopfes (13) befindliches, vorzugsweise angeformtes Halteelement (46) greift, welches ein axiales Verdrehen des Schraubenkopfes (13) gegenüber dem Keramikträger (14) und dem Anschlußbolzen (12) erlaubt.2. Glow plug according to claim 1, characterized in that the head (16) of the ceramic carrier (14) on the connection side on its circumferential surface (19) has an annular groove (18) into which an end section of the screw head (13) located on the combustion chamber is preferably formed Holding element (46) engages, which allows the screw head (13) to be rotated axially relative to the ceramic carrier (14) and the connecting bolt (12). 3. Glühkerze nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß das an der Dichtfläche (21) des Keramikträger-Kopfes (16) angeordnete Dichtelement (29) mittels bekannter Mittel (30) unverlierbar am Keramikträger-Kopf (16) festgelegt ist.3. Glow plug according to claim 1 or 2, characterized in that the on the sealing surface (21) of the ceramic carrier head (16) arranged sealing element (29) by means of known means (30) captive on the ceramic carrier head (16). 4. Glühkerze nach Anspruch 3, dadurch gekennzeichnet, daß an das brennraumseitige Endes des Dichtelementes (29) eine an sich bekannte Schutzhülse (31) angebracht ist.4. Glow plug according to claim 3, characterized in that a known protective sleeve (31) is attached to the combustion chamber end of the sealing element (29). 5. Glühkerze nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß ein mit dem Dichtsitz (47) der Brennkraftmaschine direkt oder indirekt über ein Dichtelement (29) in elektrischem Kontakt stehender Anschlußleiter (24) des Heizelements (22) bis anschlußseits von der Dichtfläche (21) des Keramikträger-Kopfes (16) geführt und mittels der elektrisch isolierenden, um den Keramikträger (14) herum angebrachten Schutzschicht (28) bedeckt ist und dann auf der Schutzschicht (28) zur Dichtfläche (21) des Keramikträger-Kopfes (16) hin wieder zurückgeführt ist.5. Glow plug according to one of claims 1 to 4, characterized in that with the sealing seat (47) of the internal combustion engine directly or indirectly via a sealing element (29) in electrical contact with the connecting conductor (24) of the heating element (22) to the connection side of the Sealing surface (21) of the ceramic carrier head (16) and covered by means of the electrically insulating protective layer (28) applied around the ceramic carrier (14) and then on the protective layer (28) to the sealing surface (21) of the ceramic support head (16) is returned. 6. Glühkerze nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß in dem schichtförmigen Anschlußleiter (23) und/oder dem schichtförmigen Anschlußleiter (24) ein schichtförmiger Überhitzungsschutz (26) und/oder ein schichtförmiger Spannungsbegrenzer (27) eingebaut ist.6. Glow plug according to one of claims 1 to 5, characterized in that in the layered connecting conductor (23) and / or the layered connecting conductor (24) a layered overheating protection (26) and / or a layered voltage limiter (27) is installed.
EP83108356A 1982-08-26 1983-08-25 Glow plug for internal combustion engines Expired EP0103775B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3231781 1982-08-26
DE19823231781 DE3231781A1 (en) 1982-08-26 1982-08-26 GLOW PLUG FOR INTERNAL COMBUSTION ENGINES

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EP0103775A2 true EP0103775A2 (en) 1984-03-28
EP0103775A3 EP0103775A3 (en) 1986-01-15
EP0103775B1 EP0103775B1 (en) 1988-05-04

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EP83108356A Expired EP0103775B1 (en) 1982-08-26 1983-08-25 Glow plug for internal combustion engines

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EP (1) EP0103775B1 (en)
JP (1) JPS5956616A (en)
DE (2) DE3231781A1 (en)

Cited By (3)

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Publication number Priority date Publication date Assignee Title
EP0945724A2 (en) * 1998-03-24 1999-09-29 Beru AG Protection tubes for sensors or glow elements
WO2004074742A1 (en) 2003-02-18 2004-09-02 Robert Bosch Gmbh Pencil type blow plug, especially a low voltage pencil type glow plug for internal combustion engines
WO2005026619A1 (en) * 2003-08-28 2005-03-24 Robert Bosch Gmbh Sheathed-element glow plug comprising a specially embedded contact element

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US4816643A (en) * 1985-03-15 1989-03-28 Allied-Signal Inc. Glow plug having a metal silicide resistive film heater
US4682008A (en) * 1985-03-22 1987-07-21 Jidosha Kiki Co., Ltd. Self-temperature control type glow plug
DE4142523A1 (en) * 1991-12-21 1993-06-24 Asea Brown Boveri RESISTANCE WITH PTC BEHAVIOR
DE10023395B4 (en) * 1999-05-13 2015-05-13 Denso Corporation Ceramic heater and mounting structure

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JPS5620929A (en) * 1979-07-30 1981-02-27 Ngk Spark Plug Co Ltd Glow plug heating element and its manufacture
GB2092670A (en) * 1981-02-07 1982-08-18 Bosch Gmbh Robert Glow plug for internal combustion engines

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DE2900984A1 (en) * 1979-01-12 1980-07-17 Heraeus Gmbh W C GLOW PLUG FOR DIESEL ENGINES
JPS5620929A (en) * 1979-07-30 1981-02-27 Ngk Spark Plug Co Ltd Glow plug heating element and its manufacture
GB2092670A (en) * 1981-02-07 1982-08-18 Bosch Gmbh Robert Glow plug for internal combustion engines

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0945724A2 (en) * 1998-03-24 1999-09-29 Beru AG Protection tubes for sensors or glow elements
EP0945724A3 (en) * 1998-03-24 2003-03-19 Beru AG Protection tubes for sensors or glow elements
WO2004074742A1 (en) 2003-02-18 2004-09-02 Robert Bosch Gmbh Pencil type blow plug, especially a low voltage pencil type glow plug for internal combustion engines
WO2005026619A1 (en) * 2003-08-28 2005-03-24 Robert Bosch Gmbh Sheathed-element glow plug comprising a specially embedded contact element

Also Published As

Publication number Publication date
EP0103775B1 (en) 1988-05-04
DE3376499D1 (en) 1988-06-09
JPS5956616A (en) 1984-04-02
JPH0319446B2 (en) 1991-03-15
EP0103775A3 (en) 1986-01-15
DE3231781A1 (en) 1984-03-01

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