EP1305858B1 - Spark plug for an internal combustion engine and method for producing a spark plug - Google Patents
Spark plug for an internal combustion engine and method for producing a spark plug Download PDFInfo
- Publication number
- EP1305858B1 EP1305858B1 EP01947128A EP01947128A EP1305858B1 EP 1305858 B1 EP1305858 B1 EP 1305858B1 EP 01947128 A EP01947128 A EP 01947128A EP 01947128 A EP01947128 A EP 01947128A EP 1305858 B1 EP1305858 B1 EP 1305858B1
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- Prior art keywords
- spark plug
- insulator
- ceramic
- electrical conductivity
- good electrical
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
- H01T13/34—Sparking plugs characterised by features of the electrodes or insulation characterised by the mounting of electrodes in insulation, e.g. by embedding
Definitions
- the invention relates to a spark plug for an internal combustion engine, with a Housing, an insulator, which is arranged in the housing and from a sintered ceramic material, and a sintered center electrode and a terminal stud, which are in electrically conductive connection with each other stand and are arranged in the insulator.
- the invention further relates to a Method for producing a spark plug.
- Spark plugs with sintered center electrode made of platinum have due to the different thermal expansions of platinum and ceramic material one small gap between the ceramic and the center electrode, which is the Ingress of air or combustion gases allows. For this reason the components must be resistant to the inside of the spark plug Be gases. It is therefore not possible, for example, in the combustion chamber side, front area of the spark plug on a burn-off resistance Incorporate carbon because the carbon at high temperatures would be oxidized by the penetrating atmospheric oxygen. In addition, for Contact pins are used only materials that are resistant to the are penetrating gases. The use of high-contact pins Thermal conductivity, such as copper, is therefore not possible.
- a spark plug according to the preamble of claim 1 is known from DE-A-19853844 known.
- the object of the invention is a spark plug of the above Such a way further develop that a gas-tight, reliable Seal is guaranteed, which can be produced inexpensively.
- the object of the invention further consists in a process for the preparation to create such a spark plug.
- the spark plug with the features of claim 1 has the same or Similar material properties for both the insulator and the cermet on, which ensures the seal. Because of the same Material properties give advantages both in the production as Also in operation: Isolator and Cermet can easily communicate with each other be sintered because they have the same shrinkage. Because insulator and Cermet also have the same thermal expansion, there are no results Column due to different thermal expansions. Due to the achieved good sealing can be in the front area of the spark plug Materials are used, which occur at the high occurring during operation Temperatures to air or combustion gases not sufficient Have resistance, for example, resistors with carbon as conductive phase or well-conductive copper pins. For the Metallic phase of the cermet is only a comparatively small amount Metal required, resulting in low cost of the spark plug.
- the ceramic phase of the cermet consists of Al 2 O 3 and the metallic phase consists of platinum or a platinum alloy.
- This cermet can be easily sintered together with the insulator since it has the same sintering properties as the insulator.
- a ceramic granulate is used, the Grains with a surface coating of the material with good electrical conductivity are provided. Due to the size difference. between the grains of the granules, which have a diameter preferably in the Range between 90 microns and 150 microns, and the powdered metal, whose particles have dimensions of the order of less than 10 ⁇ m, results after sintering a ceramic structure with.
- a network thinner Metal interconnects for example of platinum, which at a low Consumption of the metal ensures sufficient electrical conductivity. For example, it is sufficient that the metallic phase of the cermet accounts for between 10 and 15% by volume, making it more economical Dealing with the preferably used precious metal results.
- the grains of the ceramic granules with the electrically highly conductive material be coated by stirring in a dilute suspension.
- the grains in a cost effective manner with the electric conductive material, such as platinum, coat, so that after the Sintering the granules the electrically conductive network inside the cermet results.
- the electrically good conductive material under Using an example organic binder on the grains of Granules are applied or by vapor deposition or sputtering.
- a spark plug 10 which has a housing 12 which consists of metal and is provided with a screw thread 14, by means of which the spark plug can be screwed into a bore in a cylinder head of an internal combustion engine.
- a housing 12 which consists of metal and is provided with a screw thread 14, by means of which the spark plug can be screwed into a bore in a cylinder head of an internal combustion engine.
- an insulator 16 is received, which consists of a sintered ceramic material, for example Al 2 O 3 .
- a center electrode 18 and a connecting bolt 22 are received, which are in electrically conductive connection with each other.
- Connecting pin 22 and center electrode 18 is carried out in the following manner:
- the center electrode 18 is followed by a cermet 28, which is followed by a burn-off resistor 30 (possibly with intervening contact package), in turn, a contact package 32 follows, in which the connecting pin 22nd dips.
- the insulator 16 has in its interior a stepped bore whose front end 36 receives the center electrode.
- the center electrode which preferably consists of fine-grain-stabilized platinum or a fine grain-stabilized platinum alloy, has a nail head 38 which rests on the shoulder for the larger bore diameter.
- the center electrode is sintered into the insulator and is sealed by the cermet 28 above the nail head and additionally fixed.
- the Cermet 28 is made of ceramic material and a metallic phase.
- the ceramic phase the same material is used as for the insulator, so Al 2 O 3 with the known additions of sintering aids such as SiO 2 , CaO, MgO, etc.
- platinum or a platinum alloy is used for the metallic phase.
- the cermet is made by adding granules of the material of the Isolator with a grain size between 90 microns and 150 microns is provided.
- the grains of the ceramic granules are then with the as electrical conductor serving platinum or platinum alloy coated, for example, by stirring in a mixer with a dilute Platinum suspension and then drying.
- the platinum or the platinum alloy is in powder form in the suspension; the individual particles have dimensions of the order of less than 10 microns. In this way Granules are obtained with a small amount of platinum or the platinum alloy are coated. To achieve the later necessary electrical conductivity, it has been found to be sufficient if the Proportion of platinum or platinum alloy 10 to 15% by volume of the cermet accounts.
- the thus coated ceramic granules are placed in the insulator, which with a usual method was prepared and possibly at a temperature of 1000 ° C was vorgtüht to increase the strength, filled so that it above the nail head 38 of the inserted into the receiving bore 36 Center electrode 18 is located. Then the granules by means of a punch with a force of about 100 to 150 N compressed. Finally, the insulator sintered as usual at about 1600 ° C together with the granules.
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Description
Die Erfindung betrifft eine Zündkerze für einen Verbrennungsmotor, mit einem Gehäuse, einem Isolator, der in dem Gehäuse angeordnet ist und aus einem gesinterten Keramikmaterial besteht, sowie einer eingesinterten Mittelelektrode und einem Anschlußbolzen, die miteinander in elektrisch leitender Verbindung stehen und in dem Isolator angeordnet sind. Die Erfindung betrifft ferner ein Verfahren zur Herstellung einer Zündkerze.The invention relates to a spark plug for an internal combustion engine, with a Housing, an insulator, which is arranged in the housing and from a sintered ceramic material, and a sintered center electrode and a terminal stud, which are in electrically conductive connection with each other stand and are arranged in the insulator. The invention further relates to a Method for producing a spark plug.
Zündkerzen mit eingesinterter Mittelelektrode aus Platin weisen aufgrund der unterschiedlichen Wärmedehnungen von Platin und Keramikmaterial einen geringen Spalt zwischen der Keramik und der Mittelelektrode auf, der das Eindringen von Luft bzw. Verbrennungsgasen ermöglicht. Aus diesem Grunde müssen die Bauteile im Inneren der Zündkerze beständig gegenüber'diesen Gasen sein. Es ist deshalb zum Beispiel nicht möglich, im brennraumseitigen, vorderen Bereich der Zündkerze einen Abbrandwiderstand auf Kohlenstoffbasis einzubauen, da der Kohlenstoff bei den hohen Temperaturen durch den eindringenden Luftsauerstoff oxidiert würde. Außerdem können für Kontaktstifte nur Materialien verwendet werden, die beständig gegen die eindringenden Gase sind. Die Verwendung von Kontaktstiften mit hoher Wärmeleitfähigkeit, beispielsweise aus Kupfer, ist somit nicht möglich.Spark plugs with sintered center electrode made of platinum have due to the different thermal expansions of platinum and ceramic material one small gap between the ceramic and the center electrode, which is the Ingress of air or combustion gases allows. For this reason the components must be resistant to the inside of the spark plug Be gases. It is therefore not possible, for example, in the combustion chamber side, front area of the spark plug on a burn-off resistance Incorporate carbon because the carbon at high temperatures would be oxidized by the penetrating atmospheric oxygen. In addition, for Contact pins are used only materials that are resistant to the are penetrating gases. The use of high-contact pins Thermal conductivity, such as copper, is therefore not possible.
Aus der WO 97/49153 ist eine Zündkerze bekannt, bei der vorgeschlagen wird, den Kontaktstift durch eine elektrisch leitende Mischung Keramik-Metall zu ersetzen, so daß durch die dann gleichen Wärmeausdehnungskoeffizienten mechanische Spannungen vermieden werden.From WO 97/49153 a spark plug is known in which it is proposed the contact pin by an electrically conductive mixture ceramic-metal too replace, so that then the same thermal expansion coefficient mechanical stresses are avoided.
Eine Zündkerre, gemäß Oberbegriff des Anspruchs 1 ist aus DE-A- 19853844 bekannt.A spark plug according to the preamble of claim 1 is known from DE-A-19853844 known.
Die Aufgabe der Erfindung besteht darin, eine Zündkerze der eingangs genannten Art dahingehend weiterzubilden, daß eine gasdichte, zuverlässige Abdichtung gewährleistet ist, die kostengünstig hergestellt werden kann. Die Aufgabe der Erfindung besteht weiterhin darin, ein Verfahren zur Herstellung einer solchen Zündkerze zu schaffen.The object of the invention is a spark plug of the above Such a way further develop that a gas-tight, reliable Seal is guaranteed, which can be produced inexpensively. The The object of the invention further consists in a process for the preparation to create such a spark plug.
Die Zündkerze mit den Merkmalen des Patentanspruchs 1 weist gleiche oder ähnliche Materialeigenschaften sowohl für den Isolator als auch für das Cermet auf, das die Abdichtung gewährleistet. Aufgrund der gleichen Materialeigenschaften ergeben sich Vorteile sowohl bei der Herstellung als auch beim Betrieb: Isolator und Cermet können problemlos miteinander gesintert werden, weil sie denselben Schwindungsverlauf haben. Da Isolator und Cermet auch die gleiche Wärmeausdehnung haben, ergeben sich keinerlei Spalte aufgrund von unterschiedlichen Wärmeausdehnungen. Aufgrund der erzielten guten Abdichtung können im vorderen Bereich der Zündkerze Materialien verwendet werden, die bei den im Betrieb auftretenden hohen Temperaturen gegenüber Luft- oder Verbrennungsgasen keine ausreichende Beständigkeit aufweisen, beispielsweise Widerstände mit Kohlenstoff als leitfähiger Phase oder gut wärmeleitende Kontaktstifte aus Kupfer. Für die metallische Phase des Cermets ist nur eine vergleichsweise geringe Menge an Metall erforderlich, was zu niedrigen Kosten der Zündkerze führt. The spark plug with the features of claim 1 has the same or Similar material properties for both the insulator and the cermet on, which ensures the seal. Because of the same Material properties give advantages both in the production as Also in operation: Isolator and Cermet can easily communicate with each other be sintered because they have the same shrinkage. Because insulator and Cermet also have the same thermal expansion, there are no results Column due to different thermal expansions. Due to the achieved good sealing can be in the front area of the spark plug Materials are used, which occur at the high occurring during operation Temperatures to air or combustion gases not sufficient Have resistance, for example, resistors with carbon as conductive phase or well-conductive copper pins. For the Metallic phase of the cermet is only a comparatively small amount Metal required, resulting in low cost of the spark plug.
Gemäß einer bevorzugten Ausführungsform der Erfindung ist vorgesehen, daß die keramische Phase des Cermets aus Al2O3 und die metallische Phase aus Platin oder einer Platin-Legierung besteht. Dieses Cermet läßt sich problemlos zusammen mit dem Isolator sintern, da es dieselben Sintereigenschaften aufweist wie der Isolator.According to a preferred embodiment of the invention it is provided that the ceramic phase of the cermet consists of Al 2 O 3 and the metallic phase consists of platinum or a platinum alloy. This cermet can be easily sintered together with the insulator since it has the same sintering properties as the insulator.
Gemäß der bevorzugten Ausführungsform der Erfindung ist vorgesehen, daß zur Herstellung des Cermets ein Keramikgranulat verwendet wird, dessen Körner mit einer Oberflächenbeschichtung aus dem Material mit guter elektrischer Leitfähigkeit versehen sind. Aufgrund des Größenunterschiedes. zwischen den Körnern des Granulats, die einen Durchmesser vorzugsweise im Bereich zwischen 90 µm und 150 µm haben, und dem pulverförmigen Metall, dessen Partikel Abmessungen in der Größenordnung von unter 10 µm haben, ergibt sich nach dem Sintern ein Keramikgefüge mit. einem Netzwerk dünner Metall-Leiterbahnen, beispielsweise aus Platin, das bei einem geringen Verbrauch des Metalls eine ausreichende elektrische Leitfähigkeit sicherstellt. Es ist beispielsweise ausreichend, daß die metallische Phase des Cermets einen Anteil zwischen 10 und 15 Vol% einnimmt, so daß sich ein sparsamer Umgang mit dem vorzugsweise verwendeten Edelmetall ergibt.According to the preferred embodiment of the invention it is provided that for producing the cermet, a ceramic granulate is used, the Grains with a surface coating of the material with good electrical conductivity are provided. Due to the size difference. between the grains of the granules, which have a diameter preferably in the Range between 90 microns and 150 microns, and the powdered metal, whose particles have dimensions of the order of less than 10 μm, results after sintering a ceramic structure with. a network thinner Metal interconnects, for example of platinum, which at a low Consumption of the metal ensures sufficient electrical conductivity. For example, it is sufficient that the metallic phase of the cermet accounts for between 10 and 15% by volume, making it more economical Dealing with the preferably used precious metal results.
Hinsichtlich der mit dem erfindungsgemäßen Verfahren erzielten Vorteile wird auf die obigen Erläuterungen verwiesen.With regard to the advantages achieved by the method according to the invention is referred to the above explanations.
Gemäß einer bevorzugten Ausführungsform des Verfahrens ist vorgesehen, daß die Körner des Keramikgranulats mit dem elektrisch gut leitenden Material durch Rühren in einer verdünnten Suspension beschichtet werden. Auf diese Weise lassen sich die Körner in kostengünstiger Weise mit dem elektrisch leitenden Material, beispielsweise Platin, beschichten, so daß sich nach dem Sintern des Granulats das elektrisch leitende Netz im Inneren des Cermets ergibt. Alternativ kann das elektrisch gut leitende Material auch unter Verwendung eines beispielsweise organischen Bindemittels auf die Körner des Granulats aufgebracht werden oder durch Aufdampfen oder Sputtern.According to a preferred embodiment of the method is provided that the grains of the ceramic granules with the electrically highly conductive material be coated by stirring in a dilute suspension. To this Way, the grains in a cost effective manner with the electric conductive material, such as platinum, coat, so that after the Sintering the granules the electrically conductive network inside the cermet results. Alternatively, the electrically good conductive material under Using an example organic binder on the grains of Granules are applied or by vapor deposition or sputtering.
Die Erfindung wird nachfolgend anhand einer bevorzugten Ausführungsform beschrieben, die in den beigefügten Zeichnungen dargestellt ist. In den Zeichnungen zeigen:
- Figur 1 in einer teilgeschnittenen Ansicht eine erfindungsgemäße Zündkerze;
- Figur 2 in einer vergrößerten Ansicht einen Ausschnitt aus Figur 1;
- Figur 3 in einem vergrößerten Schliffbild einen Teil des isolators der erfindungsgemäßen Zündkerze mit eingesinterter Mittelelektrode;
- Figur 4 einen wiederum vergrößerten Ausschnitt aus dem Schliffbild von Figur 3.
- Figure 1 in a partially sectioned view of a spark plug according to the invention;
- Figure 2 is an enlarged view of a detail of Figure 1;
- FIG. 3 shows in an enlarged section a part of the insulator of the spark plug according to the invention with sintered center electrode;
- FIG. 4 shows an enlarged detail of the microsection of FIG. 3.
In Figur 1 ist eine Zündkerze 10 zu sehen, die ein Gehäuse 12 aufweist, das
aus Metall besteht und mit einem Einschraubgewinde 14 versehen ist, mittels
dem die Zündkerze in eine Bohrung in einem Zylinderkopf eines
Verbrennungsmotors eingeschraubt werden kann. Im Inneren des Gehäuses
12 ist ein Isolator 16 aufgenommen, der aus einem gesinterten Keramikmaterial
besteht, beispielsweise Al2O3. Im Inneren des Isolators sind eine Mittelelektrode
18 sowie ein Anschlußbolzen 22 aufgenommen, die miteinander in elektrisch
leitender Verbindung stehen. Somit kann in bekannter Weise durch Anlegen
eines Spannungspotentials zwischen einer auf den Anschlußbolzen 22
aufgeschraubten Anschlußmutter 24 und dem Gehäuse 12 ein Zündfunke
zwischen der Mittelelektrode 18 und Masseelektroden 26 erzeugt werden, die
am Gehäuse 12 angebracht sind. In Figure 1, a spark plug 10 is to be seen, which has a
Die Abdichtung und die elektrisch leitende Verbindung zwischen
Anschlußbolzen 22 und Mittelelektrode 18 wird in folgender Weise ausgeführt:
An die Mittelelektrode 18 schließt sich ein Cermet 28 an, das gefolgt wird von
einem Abbrandwiderstand 30 (ggf. mit dazwischenliegendem Kontaktpaket),
auf den wiederum ein Kontaktpaket 32 folgt, in welches der Anschlußbolzen 22
eintaucht.The seal and the electrically conductive connection between
Connecting
Die gasdichte Abdichtung wird nachfolgend anhand der Figuren 2 bis 4 im Detail beschrieben.The gas-tight seal is described below with reference to Figures 2 to 4 in Detail described.
Der Isolator 16 weist in seinem Inneren eine abgesetzte Bohrung auf, deren
vorderes Ende 36 die Mittelelektrode aufnimmt. Die Mittelelektrode, die
vorzugsweise aus feinkornstabilisiertem Platin oder einer feinkornstabilisierten
Platinlegierung besteht, weist einen Nagelkopf 38 auf, der auf dem Absatz zum
größeren Bohrungsdurchmesser aufliegt. Die Mittelelektrode ist in den Isolator
eingesintert und wird durch das Cermet 28 über dem Nagelkopf abgedichtet
und zusätzlich fixiert. Das Cermet 28 besteht aus keramischem Material und
einer metallischen Phase. Für die keramische Phase wird dasselbe Material
verwendet wie für den Isolator, also Al2O3 mit den bekannten Zusätzen an
Sinterhilfsmitteln wie SiO2, CaO, MgO u.a. Für die metallische Phase wird Platin
oder eine Platinlegierung verwendet.The
Das Cermet wird hergestellt, indem ein Granulat aus dem Material des Isolators mit einer Korngröße zwischen 90 µm und 150 µm bereitgestellt wird. Die Körner des Keramikgranulats werden anschließend mit dem als elektrischen Leiter dienenden Platin oder der Platin-Legierung beschichtet, beispielsweise durch Rühren in einem Mischer mit einer verdünnten Platinsuspension und anschließendem Trocknen. Das Platin oder die Platin-Legierung liegt in der Suspension pulverförmig vor; die einzelnen Partikel haben Abmessungen in der Größenordnung von unter 10 µm. Auf diese Weise werden Granulatkörner erhalten, die mit einer geringen Menge an Platin oder der Platin-Legierung beschichtet sind. Zur Erzielung der später notwendigen elektrischen Leitfähigkeit hat es sich als ausreichend herausgestellt, wenn der Anteil an Platin oder der Platin-Legierung 10 bis 15 Vol% des Cermets ausmacht.The cermet is made by adding granules of the material of the Isolator with a grain size between 90 microns and 150 microns is provided. The grains of the ceramic granules are then with the as electrical conductor serving platinum or platinum alloy coated, for example, by stirring in a mixer with a dilute Platinum suspension and then drying. The platinum or the platinum alloy is in powder form in the suspension; the individual particles have dimensions of the order of less than 10 microns. In this way Granules are obtained with a small amount of platinum or the platinum alloy are coated. To achieve the later necessary electrical conductivity, it has been found to be sufficient if the Proportion of platinum or platinum alloy 10 to 15% by volume of the cermet accounts.
Das so beschichtete Keramikgranulat wird in den Isolator, der mit einem
üblichen Verfahren hergestellt wurde und eventuell bei einer Temperatur von
1000° C zur Erhöhung der Festigkeit vorgegtüht wurde, eingefüllt, so daß es
oberhalb des Nagel-kopfes 38 der in die Aufnahmebohrung 36 eingesetzten
Mittelelektrode 18 liegt. Dann wird das Granulat mittels eines Stempels mit
einer Kraft von ca. 100 bis 150 N verdichtet. Schließlich wird der Isolator
zusammen mit dem Granulat wie üblich bei ca. 1600°C gesintert. Dabei ergibt
sich eine sehr gute Verbindung zwischen dem Isolator und dem Cermet, da als
Grundmaterial für das Cermet dasselbe Material wie für den Isolator verwendet
wird, sowie eine gute elektrische Leitfähigkeit des Cermets aufgrund des
Platins oder der Platin-Legierung, da beim Sintern ein Netzwerk mit dünnen
Leiterbahnen aus Platin oder der Platin-Legierung entsteht. Dies ist in den
Figuren 3 und 4 gezeigten Schnittbildern zu erkennen: Es entsteht ein nahezu
einheitliches Gefüge aus Isolator 16 und Cermet 28, das sich nur durch die im
Cermet 28 vorhandenen Leiterbahnen aus Platin oder der Platin-Legierung
unterscheidet.The thus coated ceramic granules are placed in the insulator, which with a
usual method was prepared and possibly at a temperature of
1000 ° C was vorgtüht to increase the strength, filled so that it
above the
Da für die keramische Phase des Cermets dasselbe Material verwendet wird
wie für den Isolator, ergibt sich eine besonders gute Abdichtung auf der
rückwärtigen Seite der Mittelelektrode 18. Diese Abdichtung wird auch über
lange Betriebsdauern aufrechterhalten, da das Cermet und der Isolator
dieselbe Wärmeausdehnung haben, so daß es zu keinen Wärmespannungen
und daraus resultierenden Rissen oder Spalten kommen kann. Somit kann für
den Abbrandwiderstand 30 als elektrisch leitendes Material beispielsweise
Kohlenstoff verwendet werden, obwohl dieses Material bei den
Betriebstemperaturen gegenüber Luft oder Verbrennungsgasen keine
ausreichende Beständigkeit aufweist; die Abdichtung ist so zuverlässig, daß
der Kohlenstoff mit der Luft oder den Verbrennungsgasen nicht in Berührung
kommt.Since the same material is used for the ceramic phase of the cermet
as for the insulator, results in a particularly good seal on the
rear side of the
Claims (22)
- Spark plug for an internal combustion engine, having a housing (12), an insulator (16), which is arranged in the housing and consists of a sintered ceramic material, and a sintered-in centre electrode (18) and also a connection bolt (22), which are electrically conductively connected to one another and are arranged in the insulator, a cermet (28) being connected to the centre electrode, characterized in that the ceramic phase of the cermet consists of the same material as or a similar material to the insulator, and in that the metallic phase of the cermet consists of a material with a good electrical conductivity.
- Spark plug according to Claim 1, characterized in that the ceramic phase consists of Al2O3.
- Spark plug according to Claim 2, characterized in that the ceramic phase includes sintering aids.
- Spark plug according to one of the preceding claims, characterized in that the metallic phase consists of a metal from the platinum group which is able to withstand the sintering temperature.
- Spark plug according to Claim 4, characterized in that the metallic phase consists of platinum or a platinum alloy.
- Spark plug according to one of the preceding claims, characterized in that ceramic granules, the grains of which are provided with a surface coating of the material with a good electrical conductivity, are used to produce the cermet (28).
- Spark plug according to Claim 6, characterized in that the granules have a grain size in the range between 90 µm and 150 µm.
- Spark plug according to Claim 6 and Claim 7, characterized in that the material with a good electrical conductivity is in powder form and the individual particles have a size of less than 10 µm.
- Spark plug according to one of the preceding claims, characterized in that the metallic phase of the cermet forms between 10 and 15% by volume.
- Spark plug according to one of the preceding claims, characterized in that the centre electrode (18) has a diameter of between 0.3 mm and 0.8 mm.
- Spark plug according to one of the preceding claims, characterized in that an erosion resistor (30), the conductive phase of which consists of carbon, is arranged in the interior of the insulator.
- Process for producing a spark plug according to Claim 1 using the following steps:a ceramic material is pressed in order to form an insulator (16) which is provided with a receiving bore (36) for a centre electrode;the centre electrode (18) is inserted into the receiving bore;ceramic granules, the grains of which are provided with a coating of a material of good electrical conductivity, are introduced into the insulator and compacted, with the material used for the ceramic of the ceramic granules being the same as or similar to the material used for the insulator;the insulator is sintered.
- Process according to Claim 12, characterized in that the ceramic material used is Al2O3.
- Process according to Claim 13, characterized in that sintering aids are used.
- Process according to one of Claims 13 and 14, characterized in that Al2O3 is used as material for the insulator.
- Process according to one of Claims 12 to 15, characterized in that a metal from the platinum group which is able to withstand the sintering temperature is used as the material of good electrical conductivity.
- Process according to Claim 16, characterized in that platinum or a platinum alloy is used as the material of good electrical conductivity.
- Process according to one of Claims 12 to 16, characterized in that the grains of the ceramic granules are coated with the material of good electrical conductivity by stirring in a dilute suspension.
- Process according to one of Claims 12 to 17, characterized in that the material of good electrical conductivity is applied to the granule grains using a binder.
- Process according to Claim 19, characterized in that the binder is an organic binder.
- Process according to one of Claims 12 to 17, characterized in that the material of good electrical conductivity is applied to the granule grains by vapour deposition.
- Process according to one of Claims 12 to 17, characterized in that the material of good electrical conductivity is applied to the granule grains by sputtering.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10036008A DE10036008A1 (en) | 2000-07-25 | 2000-07-25 | Spark plug for an internal combustion engine and method for producing a spark plug |
| DE10036008 | 2000-07-25 | ||
| PCT/DE2001/001703 WO2002009247A1 (en) | 2000-07-25 | 2001-05-04 | Spark plug for an internal combustion engine and method for producing a spark plug |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1305858A1 EP1305858A1 (en) | 2003-05-02 |
| EP1305858B1 true EP1305858B1 (en) | 2005-03-23 |
Family
ID=7650029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP01947128A Expired - Lifetime EP1305858B1 (en) | 2000-07-25 | 2001-05-04 | Spark plug for an internal combustion engine and method for producing a spark plug |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US6794802B2 (en) |
| EP (1) | EP1305858B1 (en) |
| JP (1) | JP2004505419A (en) |
| DE (2) | DE10036008A1 (en) |
| WO (1) | WO2002009247A1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6407101B1 (en) * | 1999-05-04 | 2002-06-18 | American Home Products Corporation | Cyanopyrroles |
| DE10344186B4 (en) * | 2003-09-24 | 2005-10-13 | Robert Bosch Gmbh | spark plug |
| DE102004063077B4 (en) * | 2004-12-28 | 2014-10-09 | Robert Bosch Gmbh | ignition device |
| EP1895953B1 (en) | 2005-05-11 | 2011-10-19 | Board of Regents, The University of Texas System | Device for treating obesity |
| US7443089B2 (en) * | 2006-06-16 | 2008-10-28 | Federal Mogul World Wide, Inc. | Spark plug with tapered fired-in suppressor seal |
| DE102006061907A1 (en) * | 2006-12-20 | 2008-06-26 | Beru Ag | Spark plug with an insulator made of high-purity alumina ceramic |
| JP4719191B2 (en) * | 2007-07-17 | 2011-07-06 | 日本特殊陶業株式会社 | Spark plug for internal combustion engine |
| US20090072694A1 (en) * | 2007-09-17 | 2009-03-19 | Steigleman Jr Robert Lee | Sparkplug having improved heat removal capabilities and method to recycle used sparkplugs |
| US8044560B2 (en) * | 2007-10-10 | 2011-10-25 | Steigleman Jr Robert Lee | Sparkplug with precision gap |
| US9651306B2 (en) * | 2013-03-15 | 2017-05-16 | Federal-Mogul Ignition Company | Method for drying seal materials for ignition devices |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1574007A (en) * | 1975-12-24 | 1980-09-03 | Johnson Matthey Co Ltd | Cermets |
| US4659960A (en) * | 1984-05-09 | 1987-04-21 | Ngk Spark Plug Co., Ltd. | Electrode structure for a spark plug |
| EP0383636A1 (en) * | 1989-02-17 | 1990-08-22 | Nippon Shokubai Co., Ltd. | Carrier for catalyst and method for production thereof |
| JPH04160061A (en) * | 1990-10-22 | 1992-06-03 | Ngk Spark Plug Co Ltd | Oxynitride ceramic sintered body and spark plug |
| JP3751682B2 (en) * | 1995-06-19 | 2006-03-01 | 日本特殊陶業株式会社 | Igniter plug |
| DE19623989C2 (en) * | 1996-06-15 | 1998-07-30 | Bosch Gmbh Robert | Spark plug for an internal combustion engine |
| JP3819586B2 (en) * | 1997-04-23 | 2006-09-13 | 日本特殊陶業株式会社 | Spark plug with resistor, resistor composition for spark plug, and method of manufacturing spark plug with resistor |
| DE19853844A1 (en) * | 1998-11-23 | 2000-05-25 | Bosch Gmbh Robert | Spark plug has a temperature resistant, low thermal expansion sealant containing ceramic and metallic components |
-
2000
- 2000-07-25 DE DE10036008A patent/DE10036008A1/en not_active Withdrawn
-
2001
- 2001-05-04 WO PCT/DE2001/001703 patent/WO2002009247A1/en active IP Right Grant
- 2001-05-04 JP JP2002514850A patent/JP2004505419A/en active Pending
- 2001-05-04 EP EP01947128A patent/EP1305858B1/en not_active Expired - Lifetime
- 2001-05-04 DE DE50105708T patent/DE50105708D1/en not_active Expired - Lifetime
- 2001-05-04 US US10/088,619 patent/US6794802B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004505419A (en) | 2004-02-19 |
| US6794802B2 (en) | 2004-09-21 |
| EP1305858A1 (en) | 2003-05-02 |
| US20030020388A1 (en) | 2003-01-30 |
| DE50105708D1 (en) | 2005-04-28 |
| DE10036008A1 (en) | 2002-02-07 |
| WO2002009247A1 (en) | 2002-01-31 |
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