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EP0227693B1 - Spark plug connector - Google Patents

Spark plug connector Download PDF

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Publication number
EP0227693B1
EP0227693B1 EP86902324A EP86902324A EP0227693B1 EP 0227693 B1 EP0227693 B1 EP 0227693B1 EP 86902324 A EP86902324 A EP 86902324A EP 86902324 A EP86902324 A EP 86902324A EP 0227693 B1 EP0227693 B1 EP 0227693B1
Authority
EP
European Patent Office
Prior art keywords
spark plug
plug connector
insulating body
connector according
section
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
EP86902324A
Other languages
German (de)
French (fr)
Other versions
EP0227693A1 (en
Inventor
Adalbert BÄUERLE
Walter Benedikt
Werner Herden
Walter Holl
Gerhard Liebing
Walter WÜRTH
Siegbert Schwab
Ludwig Bartelmae
Jürgen SCHMATZ
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0227693A1 publication Critical patent/EP0227693A1/en
Application granted granted Critical
Publication of EP0227693B1 publication Critical patent/EP0227693B1/en
Expired legal-status Critical Current

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Classifications

    • 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
    • H01T13/02—Details
    • H01T13/04—Means providing electrical connection to sparking plugs

Definitions

  • the invention is based on a spark plug connector according to the preamble of the main claim.
  • a spark plug connector known from DE-OS 2 908 051
  • the one-piece insulating body is provided as a dielectric, in and on which a metallic cylinder is fastened.
  • the cylinders serve as capacitor electrodes of a capacitor integrated in the spark plug connector, which is arranged parallel to the connection between the spark plug and the ignition cable and is discharged at the time of ignition.
  • the discharge current should be combined with the ignition current of the spark plug in order to obtain a strong ignition spark.
  • the known insulating body as a dielectric, only a capacity of the spark plug connector of up to 20 pF can be achieved, which is only able to store an insufficient amount of energy.
  • a spark plug connector with spark gap is known with an outer metallic sheath which can be connected to ground and an inner metallic connecting part which is connected to the ignition cable and spark plug connection and which is arranged in an insulating body.
  • the insulating body is divided into two longitudinal sections made of ceramic and an additional capacitor with a ceramic dielectric used between them.
  • a connection electrode of the capacitor rests on the connection part, while the other connection electrode of the capacitor rests as a spring on the metallic covering or is introduced as an electrically conductive filler between the two longitudinal sections made of ceramic and is connected to the metallic covering as a ground connection.
  • the two longitudinal sections of the insulating body and the dielectric of the additional capacitor consist of ceramic with the same thermal expansion behavior, they are attached to one another with a non-elastic casting compound.
  • the known plug connector is too expensive and complicated to manufacture, so that it is not suitable for economical, possibly automated, large-scale production.
  • a spark plug connector is known, the insulating body of which consists of two longitudinal sections which are arranged at an axial distance from one another and are connected to one another via a sleeve-shaped insulating coupling.
  • the dielectric of the additional capacitor is arranged within one of the longitudinal sections in such a way that the electrodes are fastened to the end faces of the dielectric as additional conductor rings and are guided at an angle to the connecting part or to the sheath connected to ground.
  • the invention has for its object to provide a spark plug connector which not only has a capacitor, with connection electrodes already present and with a dielectric which gives the spark plug connector a capacitance of at least 50 to 500 pF, which is arranged between the longitudinal sections of the insulating body, but above it
  • a spark plug connector with simple means made of inexpensive material with a short overall length to be electrically safe and to avoid the disadvantages of the known solutions.
  • the measures provided for in the main claim are provided to solve the problem.
  • the advantage here is that a spark plug connector is economically feasible, in which the spark plug connector can be given a relatively high capacity with a relatively small dielectric.
  • the spark energy of the spark plug is amplified to such an extent that it can ignite even lean fuel vapor / air mixtures safely and over a required service life in all operating states of an internal combustion engine.
  • the ring-like elastic electrical insulation elements advantageously make it possible to use only a short longitudinal section of the insulating body made of expensive dielectric material and to form the remaining longitudinal sections of the insulating body from inexpensive known insulating materials, which, despite considerably different thermal behavior than that of the dielectric, are independent of temperature fluctuations and shaking influences the rough operation in motor vehicles remain connected to the dielectric.
  • the electrical insulating elements between the connecting part and the metallic sheath, which form the connecting electrodes of the capacitor lie firmly against the separating surfaces of the longitudinal sections of the insulating body which run transversely through the insulating body and remain elastic at all temperatures occurring in this area of the spark plug connector.
  • the measures listed in the subclaims permit advantageous developments and improvements of the spark plug connector specified in the main claim. It is particularly advantageous to produce the ring-like electrical insulating elements from silicone rubber, from suitably adjusted epoxy resin or from polymerized plastics.
  • the electrical insulating elements reliably prevent voltage breakdowns on the separating surfaces of the longitudinal section of the insulating body which forms the dielectric of the capacitor, although the separating surfaces extend in the direction of the electrical field lines at points of high electrical field strength. It is also expedient if the parting surfaces of the longitudinal sections of the insulating body have a roughness depth R z of less than 30 ⁇ m. This can be achieved with a glaze, for example.
  • the roughness depth is to be understood as the mean value from the individual roughnesses Z, to Z5 of five successive individual measuring sections.
  • a longitudinal section of the insulating body can advantageously also be designed as a sealing cap, which can be pushed onto the insulator of the spark plug in a sealing manner.
  • the metallic covering which at least at least partially surrounds the insulating body and is closed and fastened to the spark plug at ground, at the same time to provide as a suppressor jacket.
  • the drawing shows a longitudinal section through a spark plug connector on an enlarged scale.
  • a spark plug connector has an insulating body which is formed from three longitudinal sections 1, 2 and 3 and has a continuous longitudinal bore 4.
  • a connection part 5 made of electrically conductive metal is arranged in the longitudinal bore 4.
  • one end 6 of the connecting part 5 protrudes from the longitudinal section 1 of the insulating body in order to be connected to an ignition cable (not shown) in a manner known per se and not shown in detail.
  • the end 6 is provided with a thread onto which a threaded sleeve 7 is screwed until it is firmly seated with its flange 8 on the outer end face 9 of the insulating body.
  • the other end 10 of the connecting part 5 with its flange 11 is firmly pulled onto an inner ring shoulder 12 of the longitudinal section 3 of the insulating body.
  • the end 10 of the connecting part 5 is provided with a blind hole as a receiving bore 13 into which a threaded end of a connecting bolt 14 of a spark plug 15 protrudes.
  • the thread of the connecting bolt 14 snaps onto a spring ring 16, which is arranged on the outside on the end 10 of the connecting part 5 in an annular groove 17 and projects with a latching section 18 through a slot 19 into the receiving bore 13.
  • the insulating body has at its ignition cable end the sleeve-shaped longitudinal section 1 made of ceramic insulating material, for example aluminum oxide or a thermosetting plastic or thermoplastic with sufficient heat resistance.
  • the end of the longitudinal section 1 facing away from the end face 9 is widened as a flange 20 and has an end face referred to as the separating surface 21. It runs transversely to the longitudinal axis of the insulating body and thus of the spark plug connector.
  • the separating surface 21 of the longitudinal section 1 has a surface whose roughness R z should be as small as 30 11 m, preferably less than 5 ⁇ m. This shallow roughness can best be achieved by a glaze (not shown) applied to the separating surface 21, which has a layer thickness of less than 40 IJ.m and can be produced, for example, from a commercially available glass paste No. 9137 from Dupont.
  • a first electrical insulating element 22 which has the shape of an annular disk, lies tightly against the separating surface 21 of the longitudinal section 1 with one end face.
  • an end face of the longitudinal section 2 referred to as the separating surface 23, lies tightly.
  • the longitudinal section 2 is designed in the form of a cylinder sleeve as a dielectric component. Its other end face likewise forms a separating surface 24, which extends transversely to the longitudinal axis of the insulating body and against which a second electrical insulating element 25 lies tightly. It also has the shape of an annular disc.
  • the second electrical insulation element 25 lies with its end face facing away from the dielectric component 2 against the end face 26 of the longitudinal section 3 of the insulating body.
  • the two electrical insulating elements 22 and 25 consist of a material that is elastic at all temperatures occurring in this area of the spark plug connector.
  • Such an electrical insulating element 22 or 25 can consist, for example, of an annular disk made of silicone rubber, which has a thickness of 1 mm and a Shore hardness of 50, for example.
  • the thickness of such electrical insulating elements 22, 25 can also be between 0.1 and 0.2 mm.
  • a material can be used that is liquid, soft or viscous on two separating surfaces (for example positions 21 and 26; 21 and 24; 23 and 24 or 23 and 26) and after the joining of the longitudinal sections 1 to 3 of the Insulating body is optionally subjected to an aftertreatment (for example polymerization).
  • an epoxy resin or the like is suitable, which is set in accordance with the required elasticity and to which fillers such as aluminum oxide, talc, silicate have optionally been added in a known manner to compensate for the different thermal expansion behavior of the longitudinal sections 1 to 3 of the insulating body.
  • the electrical insulating elements 22, 25 can be designed as ring disks made of polymerized plastic, for example polymide, polycarbonate, polyester, polytetrafluoroethylene, polyvinyl chloride.
  • the dielectric component 2 which belongs to a capacitor of the spark plug connector, has the shape of a hollow cylinder and concentrically surrounds with its section of the longitudinal bore 4 a section of the connecting part 5 near its end on the candle side.
  • the separating surfaces 23 and 24 of the dielectric component 2 likewise have a low roughness depth R z like that of the above-described separating surface 21 of the first longitudinal section 1. They can also be coated with a corresponding glaze known per se and not shown in detail.
  • the peripheral surface 27 of the dielectric component preferably has a diameter that is slightly smaller than the diameter of the flange 20 of the longitudinal section 1 of the insulating body.
  • Both the circumferential surface 27 and the surface of the section of the longitudinal bore 4 belonging to the dielectric component 2 are provided with a surface coating, not shown, which supports the electrical contact and which can consist, for example, of a silver-palladium alloy and is 10 ⁇ m thick.
  • the dielectric component 2 consists of a material with a dielectric constant Er of 100 to 500.
  • the dielectric component 2 can consist, for example, of a mixture of calcium titanate, barium titanate, strontium titanate, bismuth oxide and lead titanate or only calcium titanate and strontium titanate.
  • a commercially available suitable substance is supplied, for example, by the Japanese company Murata under type QQ or UF.
  • the dielectric component 2 is dimensioned such that the spark plug connector has a capacitance of 50 to 500 pF, but preferably has a capacitance of 120 to 400 pF.
  • the longitudinal section 3 of the insulating body which is in contact with the electrical insulating element 25 consists of a sufficiently elastic insulating material in order to be able to be pushed with its tubular end section 28 as a sealing cap onto the insulator 29 of the spark plug 15 in a sealing manner.
  • the end section 28 is relatively thin-walled. Its inner wall 30 delimits the connection space 31 in the circumferential direction between the spark plug connection bolt 14 and the connection part 5. It starts from the inner ring shoulder 12, on which the flange 11 of the connection part 5 is held tight.
  • the outer jacket of the longitudinal section 3 has its outer diameter at its end abutting the electrical insulating element 25, merges into a tapering conical section in a central section 32 and continues in the cylindrical section of smaller diameter of the end section 28.
  • a plug housing 33 as an outer metallic sheath is essentially tubular. It is pushed so far over the insulating body that the flange 20 of the longitudinal section 1, the dielectric component 2 and the end section of the longitudinal section 3 provided with the outer diameter of the electrical insulating element 25 are completely accommodated in its inner bore 34. An expanding end section 35 of the inner bore 34 with the outer diameter of the plug housing 33 remaining the same forms a plug-on section 36 of the spark plug connector onto the hexagon 37 of the spark plug 15.
  • the plug-on section 36 is provided with narrow parallel longitudinal slots 38.
  • the plug-on section 36 of the plug housing 33 is closed to ground by the hexagon 37 of the spark plug 15.
  • the push-on section 36 can also be widened in a manner known per se at the free end and carry a tension spring in order to achieve good contact with the hexagon 37 serving as a ground connection.
  • the free end of the plug-on section 36 could also be screwed onto the metallic transition from the hexagon 37 to the insulator 29 of the spark plug 15 in order to obtain the most uniform and tight connection possible on the entire circumference of the plug-on section 36.
  • the plug housing 33 is held on the insulating body 1 to 3 by an edge 39 placed around the outside of the flange 20 of the first longitudinal section 1 of the insulating body (for example by flanging).
  • One end of a sealing spout 40 is also held by the edge 39. It is drawn onto the section of the first longitudinal section 1 protruding from the plug housing 33. Its other end sealingly surrounds the end section of the ignition cable, also not shown, in a manner known per se and not shown.
  • the capacitor of the spark plug connector consists of the dielectric component 2, which forms only a relatively short longitudinal section of the insulating body, as well as the section of the connecting part 5 enclosed by the dielectric component 2 and the section of the connector housing 33 surrounding the dielectric component 2 as capacitor electrodes.
  • the capacitor 2, 5, 33 is connected in parallel to the spark gap of the spark plug 15.
  • a contact sleeve 41 and 42 is arranged between the respective opposite surfaces of parts 5 and 2 as well as 2 and 33 for the secure electrical connection of the roller-shaped section of the connecting part 5 to the dielectric component 2 and of the dielectric component 2 to the plug housing 33 comprising the component 2 .
  • the contact sleeves 41 and 42 can each consist, for example, of a steel mesh with a small mesh size (for example 200 to 300 11 m), which is 0.1 to 0.5 mm thick.
  • a small mesh size for example 200 to 300 11 m
  • other means supporting the electrical contact between the capacitor parts 5, 2, 33 with different thermal expansion behavior can also be used, for example an electrically conductive casting compound, graphite packing or the like.
  • the annular space receiving the contact sleeve 41 and / or the contact sleeve 42 contains only gas instead of the contact sleeves 41 and 42.
  • the annular spaces contain air and are separated by the elastic ring-shaped electrical insulating elements 22; 25 sealed at the end faces.
  • the annular spaces can each form a 0.01 mm to 0.50 mm wide annular gap.
  • Each annular gap is preferably 0.05 mm to 0.30 mm wide.
  • this condenser design is first of all the simpler design, since fewer parts are required and, for example, air is used as the means which supports the contact between the condenser parts 2, 5, 33 with different thermal expansion behavior.
  • this capacitor form, arranged in the spark plug connector, for the spark plug to which the spark plug connector is plugged has the effect that the conversion of energy during the glow and arc phase is relieved and thus the spark plug wear is reduced accordingly.
  • the described embodiment of the spark plug connector can be regarded as a partially shielded spark plug connector. It can also serve as an intermediate connector, on the end 6 of which a spark plug connector can be inserted.
  • an interference suppressor is arranged between the connection end of the connection part 5 for the spark plug and the connection end 6 for the ignition cable.
  • the connecting part 5 is divided such that the candle-side end projects through the dielectric component 2 into the first longitudinal section 1 of the insulating body and is electrically conductively and mechanically connected in the bore section 4 of the longitudinal section 1 to one end of the interference suppressor accommodated there.
  • the other end of the interference suppression resistor is then connected to a connecting part of the ignition cable in a manner known per se.
  • the plug housing 33 forms both a capacitor electrode and a suppressor jacket of the spark plug connector.
  • the plug housing 33 is to be extended as an interference suppression jacket over the first longitudinal section 1 of the insulating body which comprises the interference suppression and its connection area to the ignition cable.

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  • Spark Plugs (AREA)
  • Connector Housings Or Holding Contact Members (AREA)

Abstract

A spark plug connector which is suited to support a spark plug, in order to provide reliable ignition of even lean vaporized fuel/air mixtures. The connector has an outer metal casing (33) which can be earthed, surrounding an insulating body that is separated into longitudinal sections (1, 2, 3), through the longitudinal bore (4) of which extends a metal connection piece (5) that is linked to an ignition cable and spark plug connection. A longitudinal section (2) of the insulating body, surrounded by the metal casing (33), consists of dielectric material and, together with the metal casing (33) and the metal connection piece (5) forms a capacitor which has a capacity of between 50 and 500 pF, and essentially 120 to 400 pF. In order to prevent flashovers between the connection piece (5) and the casing (33) which is of metal in the region of the mating surfaces (21, 23; 24, 26) of the longitudinal sections (1, 2, 3) of the insulating body, annular electrical insulating elements (22; 25) are arranged between the mating surfaces (21, 23; 24, 26) which are elastic at all temperatures of the spark plug connector, such as silicon rubber, epoxy resin or polymerized plastic.

Description

Die Erfindung geht von einem Zündkerzenstecker nach der Gattung des Hauptanspruchs aus. Bei einem derartigen, aus der DE-OS 2 908 051 bekannten Zündkerzenstecker ist der einteilige Isolierkörper als Dielektrikum vorgesehen, in dem und auf dem jeweils ein metallischer Zylinder befestigt ist. Die Zylinder dienen als Kondensatorenelektroden eines in den Zündkerzenstecker integrierten Kondensators, der parallel zur Verbindung zwischen Zündkerze und Zündkabel angeordnet ist und zum Zündzeitpunkt entladen wird. Dabei soll der Entladestrom mit dem Zündstrom der Zündkerze kombiniert werden, um einen starken Zündfunken zu erhalten. Mit dem bekannten Isolierkörper als Dielektrikum läßt sich lediglich eine Kapazität des Zündkerzensteckers bis zu 20 pF erreichen, die nur eine unzureichende Energiemenge zu speichern in der Lage ist.The invention is based on a spark plug connector according to the preamble of the main claim. In such a spark plug connector known from DE-OS 2 908 051, the one-piece insulating body is provided as a dielectric, in and on which a metallic cylinder is fastened. The cylinders serve as capacitor electrodes of a capacitor integrated in the spark plug connector, which is arranged parallel to the connection between the spark plug and the ignition cable and is discharged at the time of ignition. The discharge current should be combined with the ignition current of the spark plug in order to obtain a strong ignition spark. With the known insulating body as a dielectric, only a capacity of the spark plug connector of up to 20 pF can be achieved, which is only able to store an insufficient amount of energy.

Außerdem ist aus der DE-A-3 024 667 ein Zündkerzenstecker mit Vorfunkenstrecke bekannt mit einer äußeren an Masse legbaren metallischen Umhüllung und einem inneren, mit Zündkabel- und Zündkerzenanschluß in Verbindung stehenden metallischen Anschlußteil, das in einem Isolierkörper angeordnet ist. Der Isolierkörper ist in zwei Längsabschnitte aus Keramik und einem zwischen ihnen eingesetzten zusätzlichen Kondensator mit keramischem Dielektrikum unterteilt. Dabei liegt eine Anschlußelektrode des Kondensators an dem Anschlußteil an, während die andere Anschlußelektrode des Kondensators als Feder an der metallischen Umhüllung anliegt oder als elektrisch leitende Füllmasse zwischen den beiden Längsabschnitten aus Keramik eingebracht ist und an die metallische Umhüllung als Masseverbindung angeschlossen ist. Weil die beiden Längsabschnitte des Isolierkörpers und das Dielektrikum des zusätzlichen Kondensators aus Keramik mit demselben Wärmeausdehnungsverhalten bestehen, sind sie mit nicht elastischer Vergußmasse aneinander befestigt. Außerdem ist sowohl durch die verhältnismäßig langen Längsabschnitte aus Keramik als auch durch den zusätzlichen Kondensator der bekannte Kerzenstecker zu teuer und kompliziert herzustellen, so daß er sich nicht für eine wirtschaftliche, möglichst automatisierbare Großmengenherstellung eignet.In addition, from DE-A-3 024 667 a spark plug connector with spark gap is known with an outer metallic sheath which can be connected to ground and an inner metallic connecting part which is connected to the ignition cable and spark plug connection and which is arranged in an insulating body. The insulating body is divided into two longitudinal sections made of ceramic and an additional capacitor with a ceramic dielectric used between them. Here, a connection electrode of the capacitor rests on the connection part, while the other connection electrode of the capacitor rests as a spring on the metallic covering or is introduced as an electrically conductive filler between the two longitudinal sections made of ceramic and is connected to the metallic covering as a ground connection. Because the two longitudinal sections of the insulating body and the dielectric of the additional capacitor consist of ceramic with the same thermal expansion behavior, they are attached to one another with a non-elastic casting compound. In addition, due to the relatively long longitudinal sections made of ceramic and the additional capacitor, the known plug connector is too expensive and complicated to manufacture, so that it is not suitable for economical, possibly automated, large-scale production.

Schließlich ist aus der FR-A-2 301 117 ein Zündkerzenstecker bekannt, dessen Isolierkörper aus zwei Längsabschnitten besteht, die mit axialem Abstand zueinander angeordnet und über eine Hülsenförmige isolierende Kupplung miteinander verbunden sind. Das Dielektrikum des zusätzlichen Kondensators ist innerhalb eines der Längsabschnitte derart angeordnet, daß die Elektroden als zusätzliche Leitungsringe an den Stirnseiten des Dielektrikums befestigt sind und abgekröpft zum Anschlußteil bzw. zur mit Masse verbundenen Umhüllung geführt sind. Außer den teuren zusätzlichen Kondensatorteilen und dem komplizierten Herstellen des Zündkerzensteckers ist noch von Nachteil, daß durch diesen bekannten Aufbau der Zündkerzenstecker in unerwünschter Weise verhältnismäßig lang ist.Finally, from FR-A-2 301 117 a spark plug connector is known, the insulating body of which consists of two longitudinal sections which are arranged at an axial distance from one another and are connected to one another via a sleeve-shaped insulating coupling. The dielectric of the additional capacitor is arranged within one of the longitudinal sections in such a way that the electrodes are fastened to the end faces of the dielectric as additional conductor rings and are guided at an angle to the connecting part or to the sheath connected to ground. In addition to the expensive additional capacitor parts and the complicated manufacture of the spark plug connector, it is also disadvantageous that the known spark plug connector is undesirably long due to this known construction.

Der Erfindung liegt die Aufgabe zugrunde, einen Zündkerzenstecker zu schaffen, der nicht nur einen Kondensator hat, mit ohnehin vorhandenen Anschlußelektroden und mit einem dem Zündkerzenstecker eine Kapazität von mindestens 50 bis 500 pF verleihenden Dielektrikum, welches zwischen den Längsabschnitten des Isolierkörpers angeordnet ist, sondern darüber hinaus einen Zündkerzenstecker mit einfachen Mitteln aus preiswertem Werkstoff mit kurzer Baulänge elektrisch sicher auszubilden und dabei die Nachteile der bekannten Lösungen zu vermeiden.The invention has for its object to provide a spark plug connector which not only has a capacitor, with connection electrodes already present and with a dielectric which gives the spark plug connector a capacitance of at least 50 to 500 pF, which is arranged between the longitudinal sections of the insulating body, but above it In addition, a spark plug connector with simple means made of inexpensive material with a short overall length to be electrically safe and to avoid the disadvantages of the known solutions.

Zur Lösung der Aufgabe sind die im Hauptanspruch vorgesehenen Maßnahmen vorgesehen.The measures provided for in the main claim are provided to solve the problem.

Dabei ist von Vorteil, daß ein Zündkerzenstecker wirtschaftlich realisierbar ist, in dem mit einem verhältnismäßig kleinen Dielektrikum dem Zündkerzenstecker eine verhältnismäßig hohe Kapazität verliehen werden kann. Dadurch wird eine so große Verstärkung der Funkenenergie der Zündkerze erreicht, daß sie selbst magere Kraftstoffdampf-Luft-Gemische bei allen Betriebszuständen einer Brennkraftmaschine sicher und über eine erforderliche Lebensdauer zu zünden vermag. Hierzu ermöglichen in vorteilhafter Weise die ringartigen elastischen Elektroisolierelemente nur einen kurzen Längsabschnitt des Isolierkörpers aus teuerem Dielektrikum-Werkstoff zu verwenden und die übrigen Längsabschnitte des Isolierkörpers aus preiswerten bekannten Isolierstoffen zu bilden, welche trotz erheblich anderem Wärmeverhalten als das des Dielektrikums unabhängig von Temperaturwechselbeanspruchung und Schütteleinflüssen bei dem rauhen Betrieb in Kraftfahrzeugen mit dem Dielektrikum verbunden bleiben. Darüber hinaus liegen die Elektroisolierelemente zwischen Anschlußteil und metallischer Umhüllung, welche die Anschlußelektroden des Kondensators bilden, an den quer durch den Isolierkörper verlaufenden Trennflächen der Längsabschnitte des Isolierkörpers fest an und bleiben bei allen in diesem Bereich des Zündkerzensteckers auftretenden Temperaturen elastisch.The advantage here is that a spark plug connector is economically feasible, in which the spark plug connector can be given a relatively high capacity with a relatively small dielectric. As a result, the spark energy of the spark plug is amplified to such an extent that it can ignite even lean fuel vapor / air mixtures safely and over a required service life in all operating states of an internal combustion engine. For this purpose, the ring-like elastic electrical insulation elements advantageously make it possible to use only a short longitudinal section of the insulating body made of expensive dielectric material and to form the remaining longitudinal sections of the insulating body from inexpensive known insulating materials, which, despite considerably different thermal behavior than that of the dielectric, are independent of temperature fluctuations and shaking influences the rough operation in motor vehicles remain connected to the dielectric. In addition, the electrical insulating elements between the connecting part and the metallic sheath, which form the connecting electrodes of the capacitor, lie firmly against the separating surfaces of the longitudinal sections of the insulating body which run transversely through the insulating body and remain elastic at all temperatures occurring in this area of the spark plug connector.

Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen des im Hauptanspruch angegebenen Zündkerzensteckers möglich. Besonders vorteilhaft ist es, die ringartigen Elektroisolierelemente aus Silicongummi, aus entsprechend eingestelltem Epoxidharz oder aus polymerisierten Kunststoffen herzustellen. Die Elektroisolierelemente verhindern sicher Spannungsdurchschläge an den Trennflächen des das Dielektrikum des Kondensators bildenden Längsabschnitts des Isolierkörpers, obwohl sich die Trennflächen in Richtung der elektrischen Feldlinien erstrecken an Stellen hoher elektrischer Feldstärke. Es ist außerdem zweckmäßig, wenn die Trennflächen der Längsabschnitte des Isolierkörpers eine Rauhtiefe Rz kleiner als 30 µm haben. Das kann zum Beispiel mit einer Glasur erreicht werden. Unter Rauhtiefe ist gemäß deutscher Norm (DIN 4768) der Mittelwert aus den Einzelrauhheiten Z, bis Z5 fünf aufeinanderfolgender Einzelmeßstrecken zu verstehen. Darüber hinaus kann in vorteilhafter Weise ein Längsabschnitt des Isolierkörpers zugleich als Dichtkappe ausgebildet sein, welche auf den Isolator der Zündkerze abdichtend aufschiebbar ist. Auch ist von Vorteil, die metallische Umhüllung, welche zumindest teilweise den Isolierkörper umgibt und an der Zündkerze an Masse geschlossen und befestigt ist, zugleich als Entstörmantel vorzusehen.The measures listed in the subclaims permit advantageous developments and improvements of the spark plug connector specified in the main claim. It is particularly advantageous to produce the ring-like electrical insulating elements from silicone rubber, from suitably adjusted epoxy resin or from polymerized plastics. The electrical insulating elements reliably prevent voltage breakdowns on the separating surfaces of the longitudinal section of the insulating body which forms the dielectric of the capacitor, although the separating surfaces extend in the direction of the electrical field lines at points of high electrical field strength. It is also expedient if the parting surfaces of the longitudinal sections of the insulating body have a roughness depth R z of less than 30 μm. This can be achieved with a glaze, for example. According to the German standard (DIN 4768), the roughness depth is to be understood as the mean value from the individual roughnesses Z, to Z5 of five successive individual measuring sections. In addition, a longitudinal section of the insulating body can advantageously also be designed as a sealing cap, which can be pushed onto the insulator of the spark plug in a sealing manner. Also of advantage is the metallic covering, which at least at least partially surrounds the insulating body and is closed and fastened to the spark plug at ground, at the same time to provide as a suppressor jacket.

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Die Zeichnung zeigt einen Längsabschnitt durch einen Zündkerzenstecker in vergrößertem Maßstab.An embodiment of the invention is shown in the drawing and explained in more detail in the following description. The drawing shows a longitudinal section through a spark plug connector on an enlarged scale.

Ein Zündkerzenstecker hat einen Isolierkörper, der aus drei Längsabschnitten 1, 2 und 3 gebildet ist und eine durchgehende Längsbohrung 4 hat. In der Längsbohrung 4 ist ein Anschlußteil 5 aus elektrisch leitendem Metall angeordnet. Im in der Zeichnung dargestellten Ausführungsbeispiel ragt ein Ende 6 des Anschlußteils 5 aus dem Längsabschnitt 1 des Isolierkörpers, um mit einem nicht dargestellten Zündkabel in an sich bekannter und nicht näher dargestellter Weise verbunden zu werden. Das Ende 6 ist mit Gewinde versehen, auf das eine Gewindehülse 7 geschraubt ist, bis sie mit ihrem Flansch 8 an der äußeren Stirnseite 9 des Isolierkörpers fest anliegt. Dadurch ist das andere Ende 10 des Anschlußteils 5 mit seinem Flansch 11 fest an eine Innenringschulter 12 des Längsabschnitts 3 des Isolierkörpers gezogen. Das Ende 10 des Anschlußteils 5 ist mit einem Sackloch als Aufnahmebohrung 13 versehen, in das ein mit Gewinde versehenes Ende eines Anschlußbolzens 14 einer Zündkerze 15 ragt. Dabei rastet das Gewinde des Anschlußbolzens 14 an einem Federring 16 ein, welcher außen auf dem Ende 10 des Anschlußteils 5 in einer Ringnut 17 angeordnet ist und mit einem Rastabschnitt 18 durch einen Schlitz 19 in die Aufnahmebohrung 13 ragt.A spark plug connector has an insulating body which is formed from three longitudinal sections 1, 2 and 3 and has a continuous longitudinal bore 4. In the longitudinal bore 4, a connection part 5 made of electrically conductive metal is arranged. In the embodiment shown in the drawing, one end 6 of the connecting part 5 protrudes from the longitudinal section 1 of the insulating body in order to be connected to an ignition cable (not shown) in a manner known per se and not shown in detail. The end 6 is provided with a thread onto which a threaded sleeve 7 is screwed until it is firmly seated with its flange 8 on the outer end face 9 of the insulating body. As a result, the other end 10 of the connecting part 5 with its flange 11 is firmly pulled onto an inner ring shoulder 12 of the longitudinal section 3 of the insulating body. The end 10 of the connecting part 5 is provided with a blind hole as a receiving bore 13 into which a threaded end of a connecting bolt 14 of a spark plug 15 protrudes. The thread of the connecting bolt 14 snaps onto a spring ring 16, which is arranged on the outside on the end 10 of the connecting part 5 in an annular groove 17 and projects with a latching section 18 through a slot 19 into the receiving bore 13.

In dem in der Zeichnung dargestellten Ausführungsbeispiel weist der Isolierkörper an seinem zündkabelseitigen Ende den hülsenförmigen Längsabschnitt 1 auf aus keramischem Isolierstoff beispielsweise Aluminiumoxid oder aus einem Duroplasten oder Thermoplasten mit ausreichender Wärmebeständigkeit. Das der Stirnseite 9 abgewandte Ende des Längsabschnitts 1 ist als Flansch 20 verbreitert und hat eine als Trennfläche 21 bezeichnete Stirnseite. Sie verläuft quer zur Längsachse des Isolierkörpers und somit des Zündkerzensteckers. Die Trennfläche 21 des Längsabschnitts 1 hat eine Oberfläche, deren Rauhtiefe Rz möglichst kleiner als 30 11m, bevorzugt kleiner als 5 µm sein soll. Diese geringe Rauhtiefe läßt sich am besten durch eine auf die Trennfläche 21 aufgebrachte Glasur (nicht dargestellt) erzielen, die eine Schichtdicke von weniger als 40 IJ.m hat und beispielsweise aus einer handelsüblichen Glaspaste Nr. 9137 der Firma Dupont herstellbar ist.In the embodiment shown in the drawing, the insulating body has at its ignition cable end the sleeve-shaped longitudinal section 1 made of ceramic insulating material, for example aluminum oxide or a thermosetting plastic or thermoplastic with sufficient heat resistance. The end of the longitudinal section 1 facing away from the end face 9 is widened as a flange 20 and has an end face referred to as the separating surface 21. It runs transversely to the longitudinal axis of the insulating body and thus of the spark plug connector. The separating surface 21 of the longitudinal section 1 has a surface whose roughness R z should be as small as 30 11 m, preferably less than 5 μm. This shallow roughness can best be achieved by a glaze (not shown) applied to the separating surface 21, which has a layer thickness of less than 40 IJ.m and can be produced, for example, from a commercially available glass paste No. 9137 from Dupont.

Ein erstes Elektroisolierelement 22, das die Form einer Ringscheibe hat, liegt an der Trennfläche 21 des Längsabschnitts 1 mit einer Stirnseite dicht an. An der anderen Stirnseite des Elektroisolierelements 22 liegt eine als Trennfläche 23 bezeichnete Stirnseite des Längsabschnitts 2 dicht an. Der Längsabschnitt 2 ist in Form einer Zylinderhülse als dielektrisches Bauteil ausgebildet. Seine andere Stirnseite bildet ebenfalls eine quer zur Längsachse des Isolierkörpers verlaufende Trennfläche 24, an der ein zweites Elektroisolierelement 25 dicht anliegt. Es hat ebenfalls die Form einer Ringscheibe. Das zweite Elektroisolierelement 25 liegt mit seiner dem dielektrischen Bauteil 2 abgewandten Stirnseite an der Stirnseite 26 des Längsabschnitts 3 des Isolierkörpers an.A first electrical insulating element 22, which has the shape of an annular disk, lies tightly against the separating surface 21 of the longitudinal section 1 with one end face. On the other end face of the electrical insulating element 22, an end face of the longitudinal section 2, referred to as the separating surface 23, lies tightly. The longitudinal section 2 is designed in the form of a cylinder sleeve as a dielectric component. Its other end face likewise forms a separating surface 24, which extends transversely to the longitudinal axis of the insulating body and against which a second electrical insulating element 25 lies tightly. It also has the shape of an annular disc. The second electrical insulation element 25 lies with its end face facing away from the dielectric component 2 against the end face 26 of the longitudinal section 3 of the insulating body.

Die beiden Elektroisolierelemente 22 und 25 bestehen aus einem Material, das bei allen in diesem Bereich des Zündkerzensteckers auftretenden Temperaturen elastisch ist. Ein solches Elektroisolierelement 22 bzw. 25 kann beispielsweise aus einer Ringscheibe aus Silicongummi bestehen, die beispielsweise eine Dicke von 1 mm und eine Shore-Härte von 50 hat. Die Dicke derartiger Elektroisolierelemente 22, 25 kann auch zwischen 0,1 bis 0,2 mm liegen. An Stelle des Silicongummis kann ein Material verwendet werden, das flüssig, weich oder viskos auf zwei Trennflächen (zum Beispiel Positionen 21 und 26; 21 und 24; 23 und 24 oder 23 und 26) aufgetragen und nach dem Zusammenfügen der Längsabschnitte 1 bis 3 des Isolierkörpers gegebenenfalls einer Nachbehandlung (zum Beispiel Polymerisation) unterworfen wird. Hierfür eignet sich beispielsweise ein Epoxidharz oder ähnliches, welches entsprechend der geforderten Elastizität eingestellt ist und dem gegebenenfalls in bekannter Weise Füllstoffe wie Aluminiumoxid, Talkum, Silikat zur Kompensation des unterschiedlicher Wärmeausdehnungsverhaltens der Längsabschnitte 1 bis 3 des Isolierkörpers hinzugefügt worden sind. Ebenso können die Elektroisolierelemente 22, 25 als Ringscheiben aus polymerisiertem Kunststoff beispielsweise Polymid, Polykarbonat, Polyester, Polytetrafluoräthylen, Polyvinylchlorid ausgebildet sein.The two electrical insulating elements 22 and 25 consist of a material that is elastic at all temperatures occurring in this area of the spark plug connector. Such an electrical insulating element 22 or 25 can consist, for example, of an annular disk made of silicone rubber, which has a thickness of 1 mm and a Shore hardness of 50, for example. The thickness of such electrical insulating elements 22, 25 can also be between 0.1 and 0.2 mm. Instead of the silicone rubber, a material can be used that is liquid, soft or viscous on two separating surfaces (for example positions 21 and 26; 21 and 24; 23 and 24 or 23 and 26) and after the joining of the longitudinal sections 1 to 3 of the Insulating body is optionally subjected to an aftertreatment (for example polymerization). For this purpose, for example, an epoxy resin or the like is suitable, which is set in accordance with the required elasticity and to which fillers such as aluminum oxide, talc, silicate have optionally been added in a known manner to compensate for the different thermal expansion behavior of the longitudinal sections 1 to 3 of the insulating body. Likewise, the electrical insulating elements 22, 25 can be designed as ring disks made of polymerized plastic, for example polymide, polycarbonate, polyester, polytetrafluoroethylene, polyvinyl chloride.

Das dielektrische Bauteil 2, das zu einem Kondensator des Zündkerzensteckers gehört, hat die Form eines Hohlzylinders und umgibt mit seinem Abschnitt der Längsbohrung 4 konzentrisch einen Abschnitt des Anschlußteils 5 nahe dessen kerzenseitigem Ende. Die Trennflächen 23 und 24 des dielektrischen Bauteils 2 weisen ebenfalls so eine geringe Rauhtiefe Rz auf wie die der oben beschriebenen Trennfläche 21 des ersten Längsabschnitts 1. Sie können auch mit einer entsprechenden, an sich bekannten und nicht näher dargestellten Glasur beschichtet sein. Die Umfangsfläche 27 des dielektrischen Bauteils hat in bevorzugter Weise einen Durchmesser, der geringfügig kleiner ist als der Durchmesser des Flansches 20 des Längsabschnitts 1 des Isolierkörpers. Sowohl die Umfangsfläche 27 als auch die Oberfläche des zum dielektrischen Bauteil 2 gehörenden Abschnitts der Längsbohrung 4 sind mit einer nicht dargestellten den elektrischen Kontakt unterstützenden Oberflächenbeschichtung versehen, die beispielsweise aus einer Silber-Palladium-Legierung bestehen kann und 10 µm dick ist. Das dielektrische Bauteil 2 besteht aus einem Material mit einer Dielektrizitätskonstanten Er von 100 bis 500. Das dielektrische Bauteil 2 kann beispielsweise aus einer Mischung von Calciumtitanat, Bariumtitanat, Strontiumtitanat, Wismutoxid und Bleititanat bestehen oder nur aus Calciumtitanat und Strontiumtitanat. Ein handelsüblicher geeigneter Stoff wird beispielsweise von der japanischen Firma Murata unter Typ QQ oder UF geliefert. Das dielektrische Bauteil 2 ist so bemessen, daß der Zündkerzenstecker eine Kapazität von 50 bis 500 pF aufweist, bevorzugt aber eine Kapazität von 120 bis 400 pF hat.The dielectric component 2, which belongs to a capacitor of the spark plug connector, has the shape of a hollow cylinder and concentrically surrounds with its section of the longitudinal bore 4 a section of the connecting part 5 near its end on the candle side. The separating surfaces 23 and 24 of the dielectric component 2 likewise have a low roughness depth R z like that of the above-described separating surface 21 of the first longitudinal section 1. They can also be coated with a corresponding glaze known per se and not shown in detail. The peripheral surface 27 of the dielectric component preferably has a diameter that is slightly smaller than the diameter of the flange 20 of the longitudinal section 1 of the insulating body. Both the circumferential surface 27 and the surface of the section of the longitudinal bore 4 belonging to the dielectric component 2 are provided with a surface coating, not shown, which supports the electrical contact and which can consist, for example, of a silver-palladium alloy and is 10 μm thick. The dielectric component 2 consists of a material with a dielectric constant Er of 100 to 500. The dielectric component 2 can consist, for example, of a mixture of calcium titanate, barium titanate, strontium titanate, bismuth oxide and lead titanate or only calcium titanate and strontium titanate. A commercially available suitable substance is supplied, for example, by the Japanese company Murata under type QQ or UF. The dielectric component 2 is dimensioned such that the spark plug connector has a capacitance of 50 to 500 pF, but preferably has a capacitance of 120 to 400 pF.

Der an dem Elektroisolierelement 25 anliegende Längsabschnitt 3 des Isolierkörpers besteht aus einem ausreichend elastischen Isolierstoff, um mit seinem rohrförmigen Endabschnitt 28 zugleich als Dichtkappe auf den Isolator 29 der Zündkerze 15 abdichtend aufschiebbar zu sein. Der Endabschnitt 28 ist verhältnismäßig dünnwandig ausgebildet. Seine Innenwand 30 begrenzt in Umfangsrichtung den Anschlußraum 31 zwischen Zündkerzenanschlußbolzen 14 und Anschlußteil 5. Sie geht von der Innenringschulter 12 aus, an welcher der Flansch 11 des Anschlußteils 5 dicht gehalten ist. Der Außenmantel des Längsabschnitts 3 hat an seinem am Elektroisolierelement 25 anliegendem Ende dessen Außendurchmesser, geht in einem Mittelabschnitt 32 in einen sich verjüngenden konischen Abschnitt über und setzt sich im zylindrischen Abschnitt kleineren Durchmessers des Endabschnitts 28 fort.The longitudinal section 3 of the insulating body which is in contact with the electrical insulating element 25 consists of a sufficiently elastic insulating material in order to be able to be pushed with its tubular end section 28 as a sealing cap onto the insulator 29 of the spark plug 15 in a sealing manner. The end section 28 is relatively thin-walled. Its inner wall 30 delimits the connection space 31 in the circumferential direction between the spark plug connection bolt 14 and the connection part 5. It starts from the inner ring shoulder 12, on which the flange 11 of the connection part 5 is held tight. The outer jacket of the longitudinal section 3 has its outer diameter at its end abutting the electrical insulating element 25, merges into a tapering conical section in a central section 32 and continues in the cylindrical section of smaller diameter of the end section 28.

Ein Steckergehäuse 33 als äußere metallische Umhüllung ist im wesentlichen rohrförmig ausgebildet. Es ist soweit über den Isolierkörper geschoben, daß in seiner Innenbohrung 34 der Flansch 20 des Längsabschnitts 1, das dielektrische Bauteil 2 vollständig und der mit dem Außendurchmesser des Elektroisolierelements 25 versehene Endabschnitt des Längsabschnitts 3 aufgenommen sind. Ein sich erweiternder Endabschnitt 35 der Innenbohrung 34 bei gleichbleibendem Außendurchmesser des Steckergehäuses 33 bildet einen Aufsteckabschnitt 36 des Zündkerzensteckers auf den Sechskant 37 der Zündkerze 15. Der Aufsteckabschnitt 36 ist mit schmalen parallelen Längsschlitzen 38 versehen. Der Aufsteckabschnitt 36 des Steckergehäuses 33 ist durch den Sechskant 37 der Zündkerze 15 an Masse geschlossen. Der Aufsteckabschnitt 36 kann auch in an sich bekannter Weise am freien Ende aufgeweitet sein und eine Spannfeder tragen, um einen guten Kontakt zu dem als Masseanschluß dienenden Sechskant 37 zu erreichen. Auch könnte das freie Ende des Aufsteckabschnitts 36 auf den metallischen Übergang vom Sechskant 37 zum Isolator 29 der Zündkerze 15 hin aufgeschraubt sein, um am ganzen Umfang des Aufsteckabschnitts 36 einen möglichst gleichmäßigen und dichten Anschluß zu erhalten. Das Steckergehäuse 33 ist am Isolierkörper 1 bis 3 durch einen um die Außenseite des Flansches 20 des ersten Längsabschnitts 1 des Isolierkörpers gelegten Rand 39 gehalten (beispielsweise durch Bördeln). Durch den Rand 39 ist auch ein Ende einer Abdichttülle 40 gehalten. Sie ist auf den aus dem Steckergehäuse 33 ragenden Abschnitt des ersten Längsabschnitts 1 gezogen. Ihr anderes Ende umgibt in an sich bekannter und nicht dargestellter Weise abdichtend den Endabschnitt des ebenfalls nicht dargestellten Zündkabels.A plug housing 33 as an outer metallic sheath is essentially tubular. It is pushed so far over the insulating body that the flange 20 of the longitudinal section 1, the dielectric component 2 and the end section of the longitudinal section 3 provided with the outer diameter of the electrical insulating element 25 are completely accommodated in its inner bore 34. An expanding end section 35 of the inner bore 34 with the outer diameter of the plug housing 33 remaining the same forms a plug-on section 36 of the spark plug connector onto the hexagon 37 of the spark plug 15. The plug-on section 36 is provided with narrow parallel longitudinal slots 38. The plug-on section 36 of the plug housing 33 is closed to ground by the hexagon 37 of the spark plug 15. The push-on section 36 can also be widened in a manner known per se at the free end and carry a tension spring in order to achieve good contact with the hexagon 37 serving as a ground connection. The free end of the plug-on section 36 could also be screwed onto the metallic transition from the hexagon 37 to the insulator 29 of the spark plug 15 in order to obtain the most uniform and tight connection possible on the entire circumference of the plug-on section 36. The plug housing 33 is held on the insulating body 1 to 3 by an edge 39 placed around the outside of the flange 20 of the first longitudinal section 1 of the insulating body (for example by flanging). One end of a sealing spout 40 is also held by the edge 39. It is drawn onto the section of the first longitudinal section 1 protruding from the plug housing 33. Its other end sealingly surrounds the end section of the ignition cable, also not shown, in a manner known per se and not shown.

Der Kondensator des Zündkerzensteckers besteht aus dem dielektrischen Baueil 2, das nur einen verhältnismäßig kurzen Längsabschnitt des Isolierkörpers bildet sowie aus dem vom dielektrischen Bauteil 2 umschlossenen Abschnitt des Anschlußteils 5 und dem das dielektrische Bauteil 2 umgebenden Abschnitt des Steckergehäuses 33 als Kondensatorelektroden. Der Kondensator 2, 5, 33 ist parallel zur Funkenstrecke der Zündkerze 15 geschaltet. Zur sicheren elektrischen Verbindung des walzenförmigen Abschnitts des Anschlußteils 5 mit dem dielektrischen Bauteil 2 sowie des dielektrischen Bauteils 2 mit dem das Bauteil 2 umfassenden Steckergehäuse 33 ist zwischen den jeweiligen gegenüberliegenden Flächen der Teile 5 und 2 sowie 2 und 33 eine Kontakthülse 41 bzw. 42 angeordnet. Die Kontakthülsen 41 und 42 können jeweils beispielsweise aus einem Stahlgitter geringer Maschenweite (zum Beispiel 200 bis 300 11m) bestehen, das 0,1 bis 0,5 mm dick ist. An Stelle der Kontakthülsen 41 und 42 können auch andere den elektrischen Kontakt zwischen den Kondensatorteilen 5, 2, 33 mit unterschiedlichem Wärmeausdehnungsverhalten unterstützende Mittel verwendet werden, beispielsweise eine elektrisch leitfähige Gußmasse, Graphitpackungen oder ähnliches.The capacitor of the spark plug connector consists of the dielectric component 2, which forms only a relatively short longitudinal section of the insulating body, as well as the section of the connecting part 5 enclosed by the dielectric component 2 and the section of the connector housing 33 surrounding the dielectric component 2 as capacitor electrodes. The capacitor 2, 5, 33 is connected in parallel to the spark gap of the spark plug 15. A contact sleeve 41 and 42 is arranged between the respective opposite surfaces of parts 5 and 2 as well as 2 and 33 for the secure electrical connection of the roller-shaped section of the connecting part 5 to the dielectric component 2 and of the dielectric component 2 to the plug housing 33 comprising the component 2 . The contact sleeves 41 and 42 can each consist, for example, of a steel mesh with a small mesh size (for example 200 to 300 11 m), which is 0.1 to 0.5 mm thick. Instead of the contact sleeves 41 and 42, other means supporting the electrical contact between the capacitor parts 5, 2, 33 with different thermal expansion behavior can also be used, for example an electrically conductive casting compound, graphite packing or the like.

Als besonders vorteilhaft hat sich noch herausgestellt, daß der die Kontakthülse 41 und/oder der die Kontakthülse 42 aufnehmende Ringraum an Stelle der Kontakthülsen 41 und 42 lediglich Gas enthält. Beispielsweise enthalten die Ringräume Luft und sind durch die elastischen ringscheibenförmigen Elektroisolierelemente 22; 25 an den Stirnseiten abdichtend verschlossen. Die Ringräume können jeweils einen 0,01 mm bis 0,50 mm breiten Ringspalt bilden. Vorzugsweise ist jeder Ringspalt 0,05 mm bis 0,30 mm breit. Eine derartige in dem Ringraum zwischen dem dielektrischen Bauteil 2 und dem einen und/oder anderen Anschlußteil 5 bzw. 33 des Kondensators eingeschlossene Luftschicht bleibt in einem Spannungsbereich zwischen 5000 V und 500 V elektrisch leitend.It has also been found to be particularly advantageous that the annular space receiving the contact sleeve 41 and / or the contact sleeve 42 contains only gas instead of the contact sleeves 41 and 42. For example, the annular spaces contain air and are separated by the elastic ring-shaped electrical insulating elements 22; 25 sealed at the end faces. The annular spaces can each form a 0.01 mm to 0.50 mm wide annular gap. Each annular gap is preferably 0.05 mm to 0.30 mm wide. Such an air layer enclosed in the annular space between the dielectric component 2 and the one and / or other connection part 5 or 33 of the capacitor remains electrically conductive in a voltage range between 5000 V and 500 V.

Die Vorteile dieser Kondensatorausbildung liegen zunächst bei der einfacheren Bauart, da weniger Teile benötigt werden und beispielsweise Luft als das den Kontakt zwischen den Kondensatorteilen 2, 5, 33 mit unterschiedlichem Wärmeausdehnungsverhalten unterstützende Mittel dient. Außerdem wird mit dieser im Zündkerzenstecker angeordneten Kondensatorform für die Zündkerze, auf welche der Zündkerzenstecker gesteckt wird, bewirkt, daß das Umsetzen von Energie während der Glimm- und Bogenphase entlastet und somit der Zündkerzenverschleiß entsprechend reduziert wird.The advantages of this condenser design are first of all the simpler design, since fewer parts are required and, for example, air is used as the means which supports the contact between the condenser parts 2, 5, 33 with different thermal expansion behavior. In addition, this capacitor form, arranged in the spark plug connector, for the spark plug to which the spark plug connector is plugged has the effect that the conversion of energy during the glow and arc phase is relieved and thus the spark plug wear is reduced accordingly.

Die beschriebene Ausführungsform des Zündkerzensteckers kann als teilgeschirmter Zündkerzenstecker angesehen werden. Er kann auch als Zwischenstecker dienen, auf dessen Ende 6 ein Zündkerzenstecker steckbar ist.The described embodiment of the spark plug connector can be regarded as a partially shielded spark plug connector. It can also serve as an intermediate connector, on the end 6 of which a spark plug connector can be inserted.

Bei einem Zündkerzenentstörstecker ist ein Entstörwiderstand zwischen dem Anschlußende des Anschlußteils 5 für die Zündkerze und dem Anschlußende 6 für das Zündkabel angeordnet. Dazu ist das Anschlußteil 5 derart unterteilt, daß das kerzenseitige Ende durch das dielektrische Bauteil 2 bis in den ersten Längsabschnitt 1 des Isolierkörpers ragt und im Bohrungsabschnitt 4 des Längsabschnitts 1 mit einem Ende des dort untergebrachten Entstörwiderstands elektrisch leitend und mechanisch verbunden ist. Das andere Ende des Entstörwiderstands ist dann in an sich bekannter Weise an ein Anschlußteil des Zündkabels angeschlossen.In the case of a spark plug suppressor, an interference suppressor is arranged between the connection end of the connection part 5 for the spark plug and the connection end 6 for the ignition cable. For this purpose, the connecting part 5 is divided such that the candle-side end projects through the dielectric component 2 into the first longitudinal section 1 of the insulating body and is electrically conductively and mechanically connected in the bore section 4 of the longitudinal section 1 to one end of the interference suppressor accommodated there. The other end of the interference suppression resistor is then connected to a connecting part of the ignition cable in a manner known per se.

Das Steckergehäuse 33 bildet im dargestellten Ausführungsbeispiel sowohl eine Kondensatorelektrode als auch einen Entstörmantel des Zündkerzensteckers. Bei einem Zündkerzenstecker mit Entstörwiderstand ist das Steckergehäuse 33 als Entstörmantel noch über den den Entstörwiderstand und dessen Anschlußbereich zum Zündkabel umfassenden ersten Längsabschnitt 1 des Isolierkörpers zu verlängern.In the exemplary embodiment shown, the plug housing 33 forms both a capacitor electrode and a suppressor jacket of the spark plug connector. In the case of a spark plug connector with interference suppression, the plug housing 33 is to be extended as an interference suppression jacket over the first longitudinal section 1 of the insulating body which comprises the interference suppression and its connection area to the ignition cable.

Claims (11)

1. Spark plug connector having an outer metal casing (33) which can be earthed and an inner metal connection piece (5) which is linked to an ignition cable and spark plug connection (6, 10 to 13) and is arranged in an insulating body which is divided into longitudinal sections (1, 2, 3) and consists of material having a high heat resistance and a dielectric constant, casings (33), connection piece (5) and at least one longitudinal section (2) of the insulating body (1, 2, 3), lying therebetween as dielectric imparting to the spark plug connector a capacitance of 50 to 500 pF and surrounding at least one section of the metal connection piece (5), forming a capacitor, characterized in that annular electrical insulating elements (22; 25) which rest firmly on the facing separation surfaces (21, 23; 24, 26) and are composed of a material which is elastic at all temperatures occuring in this region of the spark plug connector are arranged between the separation surfaces (21, 23; 24, 26) of the longitudinal sections (1,2,3), which separation surfaces extend transversely through the insulating body (1, 2, 3).
2. Spark plug connector according to Claim 1, characterized in that the annular electrical insulating elements (22; 25) consist of silicone rubber.
3. Spark plug connector according to Claim 1, characterized in that the annular electrical insulating elements (22; 25) consist of epoxy resin containing fillers added in a known manner, if required, to compensate the different thermal expansion behaviour of the involved longitudinal sections (1, 2, 3) of the insulating body.
4. Spark plug connector according to Claim 1, characterized in that the annular electrical insulating elements (22; 25) consist of polymerized plastics.
5. Spark plug connector according to one of Claims 1 to 4, characterized in that the separation surfaces (21, 23;24, 26) of the involved longitudinal sections (1, 2, 3) of the insulating body have a peak- to-valley height (Rz) less than 30 11m.
6. Spark plug connector according to Claim 5, characterized in that the separation surfaces (21, 23; 24, 26) of the involved longitudinal sections (1, 2, 3) of the insulating body have a preferred peak- to-valley height (Rz) less than 5 µm.
7. Spark plug connector according to one of Claims 1 to 6, characterized in that the separation surfaces (21,23; 24, 26) of the longitudinal sections (1, 2, 3) are provided with a glaze layer.
8. Spark plug connector according to one of Claims 1 to 7, characterized in that the annular gap between the connection piece (5) and the dielectric component (2) and/or the annular gap between the dielectric component (2) and the connector housing (33) is 0,01 to 0,50 mm wide and is filled only with gas.
9. Spark plug connector according to Claim 8, characterized in that the annular gaps are 0,05 to 0,30 mm wide.
10. Spark plug connector according to Claim 1, characterized in that the longitudinal section (3) of the insulating body which is on the spark-plug side merges into a sealing cap (28) which can be pushed onto the insulator (29) of a spark plug (15).
11. Spark plug connector according to Claim 1, characterized in that the metal casing (33) can be secured as suppressor jacket on a section (37) of a spark plug (15), which section is earthed.
EP86902324A 1985-05-31 1986-04-10 Spark plug connector Expired EP0227693B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3519512 1985-05-31
DE3519512 1985-05-31
DE19863600509 DE3600509A1 (en) 1985-05-31 1986-01-10 SPARK PLUG
DE3600509 1986-01-10

Publications (2)

Publication Number Publication Date
EP0227693A1 EP0227693A1 (en) 1987-07-08
EP0227693B1 true EP0227693B1 (en) 1989-09-06

Family

ID=25832716

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86902324A Expired EP0227693B1 (en) 1985-05-31 1986-04-10 Spark plug connector

Country Status (4)

Country Link
EP (1) EP0227693B1 (en)
DE (2) DE3600509A1 (en)
ES (1) ES8707825A1 (en)
WO (1) WO1986007206A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6360706B1 (en) * 2000-03-03 2002-03-26 Delphi Technologies, Inc. Shield and spring interface to a spark plug from a pencil coil
DE202011050966U1 (en) 2011-08-11 2011-10-13 Motortech Gmbh spark plug

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4082980A (en) * 1975-02-13 1978-04-04 Murata Manufacturing Co., Ltd. Spark plug cap providing a capacitor in parallel with the spark cap
DE3024667C2 (en) * 1980-06-30 1986-01-09 Bloss, Werner Heinz, Prof. Dr.-Ing., 7065 Winterbach Spark plug connector

Also Published As

Publication number Publication date
ES555554A0 (en) 1987-08-16
DE3600509A1 (en) 1986-12-04
WO1986007206A1 (en) 1986-12-04
EP0227693A1 (en) 1987-07-08
DE3665517D1 (en) 1989-10-12
ES8707825A1 (en) 1987-08-16

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