EP2742571B1 - Spark plug connector - Google Patents

Description

The invention relates to a spark plug connector comprising a plug body with a spark plug Hochspannungskontaktierung for connecting to and with a spark plug, formed as an insulator, on the spark plug Hochspannungskontaktierungs-far side entering the plug body ignition cable for transmitting an ignition voltage of a Zündspannungsquelle to the spark plug, wherein the plug body a Joint on the spark plug high-voltage-contact-far side for receiving, storage and / or connection of a Zündstecker the widening structural element and the structural element is arranged at the connection point such that the structural element extends the plug body on the spark plug Hochspannungskontaktierungs-far side, wherein the ignition cable from the structural element held and / or guided over the length thereof.

Under a spark plug and spark plug extensions or ignition coil extensions and the like are to be understood, which serve to contact spark plugs of all types. Among spark plugs u.a. conventional spark plugs for generating a high-voltage spark to understand. Next spark plugs are also other ignition means to understand that serve the ignition of a gas or fuel-air mixture in the combustion chamber of an engine.

Different spark plug connectors, spark plug extensions and spark plug high voltage contacts are known in the prior art.

Spark plug plugs transfer ignition voltages of up to 50,000 volts from an ignition coil to the spark plug and should have a service life of 30,000 operating hours and more under extreme environmental conditions, such as high thermal cycling and high and sustained operating temperatures, as well as aggressive media environments. The insulators of spark plug connectors have to withstand about 10,000 to 40,000 volts permanently, possibly even peak values of 50,000 volts, and are made according to the prior art over the entire length of high-quality, expensive PTFE. The insulator simultaneously forms the mechanically supporting structure of the plug.

From the EP 0 362 777 A1 a high-voltage cable device designed as a spark plug connector is known which comprises a plug body with a spark plug high-voltage contact for connecting to and with a spark plug, wherein the plug body is formed as an insulator. Further, on the spark plug Hochspannungskontaktierungs-far side into the plug body entering ignition cable for transmitting an ignition voltage of a Zündspannungsquelle to the spark plug is provided, wherein the plug body has a connection point on the spark plug Hochspannungskontaktierungs far side for supporting and / or connection of a Zündstecker the structural element widening the structural element is arranged at the connection point such that the structural element extends the plug body on the spark plug high-voltage-contact-far side, wherein the ignition cable is held and / or guided by the structural element over its length.

Another spark plug is among others from the DE 196 112 83 C1 known. It is known an ignition connection for internal combustion engines with a spark plug, wherein the spark plug with a plug contact for the electrode terminal of a spark plug, with a the Plug contact enveloping connector sleeve and is provided with a connection for an ignition cable. The spark plug also consists of a one-piece, rigid and load-bearing plug sleeve made of an insulating material with a high melting point and high dielectric strength, such as polytetrafluoroethylene (PTFE), the plug sleeve in the plug shaft of an engine cylinder, opposite this sealed and designed to be elastically feasible. The plug sleeve is also sealed against the inserted into it ceramic shaft of the spark plug and elastically feasible. Furthermore, a ceramic inlet is provided in the plug sleeve, which has the plug contact and the ignition cable connection, the plug contact and the ignition cable connection being embedded in the ceramic insert in such an insulated manner that the ceramic projects beyond the plug contact and the connection for the ignition cable in the axial direction.

Next is from the DE 10 2010 016 881 an electrical component with electrical functional part and an insulator for high voltage applications, in particular ignition systems known, wherein the insulator is a hollow body and the electrical functional part is inserted in the hollow body in a potting compound, characterized in that the insulator consists of polyphenylene sulfide with glass fiber content.

The DE 33 02 878 A1 shows a spark plug with a Zündkabelanschluss, which has a large shaft length and at its spark plug remote end has a Aufsteckadapter that is to seal the deep candle niche of the motor housing and supports the long Kerzensteckerschaft. However, the plug connector shaft is not broken down into a plug body and a structural element inserted therein, but has a two-layer construction, namely an inner insulating body with an elastic insulating sleeve.

Next describes the DE 36 00 509 A1 Although a spark plug, which is divided into three longitudinal sections, but the upper longitudinal section in the figure is not used to guide and support an ignition cable, but is part of the spark plug, to which the ignition cable is connected.

The US 2,685,872 relates to a spark plug having a two-part insulating body, wherein the combustion chamber further part may be made of a less expensive material. However, this document does not describe a spark plug connector, nor a separately applied structural element for supporting / guiding the ignition cable.

Furthermore, the describes EP 2 204 888 A1 a plug-type connector to connect an ignition cable to a spark plug. This plug-like component has an insulating body as Gießharzformstück with an elastic sheath. However, the component is not divided into a plug body and a thereto prolonged attached structural element.

Due to larger engines and new design models for engines requires very long spark plug, which realize, for example, by a shaft in the engine block contacting a spark plug with a high voltage source or the like. Spark plug connectors are currently manufactured in lengths of up to one meter and, for example, are made entirely of polytetrafluoroethylene (PTFE), which leads to considerable costs. Due to their high weight, the spark plug connectors are susceptible to strong engine vibration, which severely limits their life. At the same time, however, the spark plug connectors must be able to insulate high voltages, so that there are special requirements for these spark plug connectors in terms of strength, weight and, in particular, insulating capability.

The present invention has for its object to show a spark plug, which allows the stress of To reduce spark plug connectors due to mass vibrations, while the insulating effect is to be realized at a very high level.

This object is achieved with an arrangement according to claim 1.

The fact that the material of the structural element has a higher rigidity and higher specific strength and / or a lower density than the material of the plug body, the weight of the entire spark plug is significantly reduced compared to the known in the art spark plug, but the properties of a conventional Plug body remain intact, in particular, the component strength is not limited.

In particular, by appropriate mass reduction, the contact stresses in engine vibrations significantly reduced, resulting in a significantly increased life of the spark plug connector leads, since the contact wear is significantly lower.

The material of the plug body is ceramic and / or a plastic, in particular polytetrafluoroethylene (PTFE). The material of the structural element is a plastic,
preferably provided with reinforcing fibers, more preferably a high performance plastic having an impact strength of 9 to 12 kJ / m ² , a heat resistance up to about 260 ° C and / or a high melting temperature of 280 ° C, offset with a glass fiber content of 20 to 50%, in particular 30 to 40%. More preferably, the structural member is polyphenylene sulfide (PPS) having a glass fiber content of 30 to 40%, preferably 40% (GF40), this material having the best cost / benefit ratio and the best durable performance in terms of stability after appropriate series of experiments.

Further, the ignition cable is guided from the connection point, coming from the plug body, within the structural element, wherein preferably the Zündkabeldurchführung is formed within the structural element as a channel, particularly preferably as a closed channel, and a larger diameter than the outer diameter of the ignition cable. The ignition cable is thus optimally supported in the structural element, which wear is counteracted due to vibration and elevated temperatures at the ignition cable.

If the connection point or the connecting element forms a permanent connection between the plug body and the structural element, wherein the connection of the plug body and the structural element is produced by gluing, screwing, bayonet locking, pressing and / or welding, this is a conclusive connection realized. An appropriate design can also on the Junction remote side be provided to secure the structural element.

Characterized in that the structural element on the spark plug Hochspannungskontaktierungs-far side has a cable outlet, preferably the cable outlet firmly locks the ignition cable and / or seals against external influences, particularly preferably designed as a silicone or rubber grommet, on the one hand a good seat and guaranteed others, the inner life is protected from external influences.

For further improvement, the structural element has a fastening and / or holding means for fastening and / or lateral guidance of the structural element at a point fixed relative to the spark plug, preferably on the engine, more preferably in or on the spark plug shaft, shaft and / or valve cover, wherein the attachment is preferably designed as a flange. At the same time, the flange serves as a catch and baffle plate for explosively ejected spark plug fragments in the event of engine malfunction and protects service personnel from injury. Alternatively, a rubber grommet or a rubber cap is used for guiding or fixing.

Further possible advantageous embodiments are given, if the subject of the present invention with the inventive objects of the publications DE 196 112 83 C1 and DE 10 2010 016 881 , which were initially appreciated in the art, is combined.

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings.

Fig. 0

eine schematische Darstellung eines Zündkerzensteckers des nächstkommenden Standes der Technik;

Fig. 1

eine schematische Darstellung eines ersten Ausführungsbeispiels der erfindungsgemäßen Zündkerzensteckers;

Fig. 2a

eine schematische Darstellung des erfindungsgemäßen Strukturelements für einen Zündkerzenstecker;

Fig. 2b

eine schematische Darstellung des erfindungsgemäßen Steckerkörpers (Isolator) für einen Zündkerzenstecker;

Fig. 3

eine schematische Darstellung des erfindungsgemäßen Zündkerzensteckers in einer Schnitt-Darstellung;

Fig. 4

eine schematische Darstellung des erfindungsgemäßen Zündkerzensteckers in einer Schnitt-Darstellung mit einem Flansch sowie einer End-Gummikappe und

Fig. 5

eine schematische Darstellung des erfindungsgemäßen Zündkerzensteckers in einer Schnitt-Darstellung mit einer End-Gummikappe und einer Gummitülle.

Show:

Fig. 0

a schematic representation of a spark plug connector of the closest prior art;

Fig. 1

a schematic representation of a first embodiment of the spark plug according to the invention;

Fig. 2a

a schematic representation of the structural element according to the invention for a spark plug;

Fig. 2b

a schematic representation of the plug body according to the invention (insulator) for a spark plug;

Fig. 3

a schematic representation of the spark plug according to the invention in a sectional view;

Fig. 4

a schematic representation of the spark plug according to the invention in a sectional view with a flange and an end rubber cap and

Fig. 5

a schematic representation of the spark plug according to the invention in a sectional view with an end rubber cap and a rubber grommet.

In Fig. 0 is a schematic representation of a spark plug connector of the closest prior art shown.

The spark plug connector 1 consists of a plug body 21 which is formed as an insulator. In the interior of the plug body 21, an ignition cable 3 is guided, that directs the ignition voltage from a Zündspannungsquelle 5 to the spark plug 6. In the interior, a Entstöreinsatz 33 is still shown, wherein the Entstöreinsatz 33 has an integrated suppression element 331.

The material of the plug body 21 is made of polytetrafluoroethylene (PTFE). This material is designed over the entire length of the plug body 21. The length of such a spark plug connector 1 can be up to one meter.

However, the costs for such a designed plug body 21 are already very high on the material side, which is why cheaper alternatives have been used as insulator material, but which do not have the same properties, as it has the polytetrafluoroethylene (PTFE). In particular, its very good insulation is the main reason for the preferred use as a material for spark plug 1. There is a continuous insulator ago.

At the high-voltage contact-far end of the spark plug 1 has a seal, which also ensures that no impurities enter the interior of the plug body 21 and further held the ignition cable 3 and is relieved of strain.

In Fig. 1 is a schematic representation of a first embodiment of the spark plug according to the invention 1 shown.

The spark plug connector 1 now has two different regions: a first region, the connector body 21, which corresponds to the prior art according to Fig. 0 in the first 10 to 20 cm (near the spark plug), and a second region, the structural element 22.

The structural element 22 is connected to the connector body 21 at a connection point or via a connecting element 23. The plug body 21 now assumes the same or similar function of the plug body 21 as in FIG Fig. 0 trained and presented.

The plug body 21 is also made of polytetrafluoroethylene (PTFE) in this embodiment in order to realize sufficient insulation in the vicinity of the spark plug coupling. The structural element 22 in this exemplary embodiment consists of polyphenylene sulfide (PPS) with a glass fiber content of 40% (GF40) and forms a retaining, inferior insulating structural element 22. The structural element 22 is a mechanically supporting part and serves to guide and position the ignition cable 3, less the insulation of the spark plug connector 1.

Experiments, simulations and calculations have shown in this context that only the vicinity of the plug body 21 to the spark plug 6 must be isolated over a length of about 10 to 20 cm, then the necessary insulation would be guaranteed. Nevertheless, it is now necessary to design the spark plug connector over the remaining length, which is now ensured by the structural element 22.

In Fig. 2a is a schematic representation of the structural element 22 according to the invention for a spark plug 1 is shown.

The structural element 22 essentially has the constituents that consist of Fig. 1 already explained. In particular, the transition region to the plug body, namely the connection point 23, is shown here. The connection of the structural element 22 with the plug body 21 can take place, for example, via a detent, a screw connection, a bayonet closure, a clamping or a gluing. Alternatively, the materials can also be connected to one another via a welding method, preferably an ultrasonic welding method, if necessary via an inserted contacting element.

The structural element 22 is in particular in a preferred embodiment dimensionally stable, has a material melting point of about 280 ° C and is insensitive to chemicals.

The structural element 22 can in particular be inexpensively manufactured by injection molding and can be kept available in stock in various length graduations.

In Fig. 2b is a schematic representation of the plug body according to the invention 21 (insulator) for a spark plug 1 is shown.

The plug body 21 essentially comprises the elements which consist of Fig. 0 are known, supplemented by the connection point or the connecting element 23. The sleeve consists in particular of polytetrafluoroethylene (PTFE).

In Fig. 3 is a schematic representation of the spark plug according to the invention 1 shown in a sectional view.

As a further essential elements of the spark plug 1 are still the spark plug Hochspannungskontaktierung 35 to the spark plug 6, as well as the Hochspannungskontaktierung 34 to call. The ignition cable 3 consists essentially of a high voltage conductor 31 and a high voltage insulation 32nd

Furthermore, the potting material 4 is to mention that is preferably used here. By means of the potting compound, the electrical functional part (suppression element) is embedded in a separate insulating sleeve. All other elements essential to the invention have already been explained in the preceding description of the figures. Reference is made to these figures.

In Fig. 4 the spark plug connector 1 according to the invention is shown in a sectional view with a flange 72 and an end rubber cap 71.

In particular, the flange 72 is provided in a metal version on the structural element 22 here. This metal flange 72 serves for screw fixation of the spark plug connector 1, for example on or on the valve cover and / or plug shaft.

Further, the spark plug 1 has an end rubber cap 71, which is angled in this embodiment by 90 ° and so the ignition cable 3 at the upper end of the spark plug 1 at an angle of 90 ° leads from the spark plug 1.

Fig. 5 shows a schematic representation of the spark plug according to the invention 1 in a sectional view with an end rubber cap 71 and a rubber grommet 73rd

The seal at the end of the spark plug 1 is made with an end rubber cap 71, which protects the interior of the spark plug 1 from contamination and the like.

Furthermore, a rubber grommet 73 is provided or pushed on the structural element 22. The rubber grommet 73 may be configured differently. Both length and circumference and material of the rubber grommet 73 can be adapted to the circumstances (candle shaft, etc.). The rubber grommet 73 serves to fix and guide the spark plug 1 in the plug shaft of the engine.

LIST OF REFERENCE NUMBERS

1

spark plug

21

Plug body (insulator)

22

structural element

23

Joint / connector

3

ignition cable

31

High voltage conductor

32

High-voltage insulation

33

Entstöreinsatz

331

integrated suppression element

34

High-voltage contact

35

Zündkerzenhochspannungskontaktierung

4

grout

5

ignition voltage source

6

spark plug

71

End rubber cap

72

flange

73

rubber grommet

Claims (8)

1. A spark plug connector (1) comprising a connector body (21) with spark plug high voltage contact (35) for production of a connection to and with a spark plug (6), in the form of an insulator, an ignition cable (3), entering into the connector body (21) on the side remote from the spark plug high voltage contact, for transmission of an ignition voltage of an ignition voltage source (5) to the spark plug (6), wherein the connector body (21) has a connecting site (23), on the side remote from the spark plug high voltage contact, to receive, mount and/or connect a structural element (22) extending the spark plug connector (1) and the structural element (22) is arranged at the connecting site (23) in such a manner that the structural element (22) lengthens the connector body (21) on the side remote from the spark plug high voltage contact, wherein the ignition cable (3) is held and/or guided over its length by the structural element (22), characterized in that the material of the structural element (22) has greater stiffness and strength and/or less density accompanied at the same time by less material usage than the material of the connector body (21).
2. A spark plug connector (1) according to claim 1, characterized in that the material of the connector body (21) is ceramic or a plastics material, in particular polytetrafluoroethylene (PTFE).
3. A spark plug connector (1) according to claim 1 or 2, characterized in that the material of the structural element (22) is a plastics material provided with reinforcing fibers, preferably a high-performance plastics material with an impact toughness from 9 to 12 kJ/m², a thermal dimensional stability up to approximately 260°C and/or a high melting temperature of 280°C to which there is added a glass fiber proportion from 20 to 50%, in particular 30 to 40%.
4. A spark plug connector (1) according to claim 1, 2 or 3, characterized in that from the connecting site (23), the ignition cable (3), issuing from the connector body (21), is guided within the structural element (22), wherein the ignition cable feedthrough within the structural element (22) is in the form of a channel, particularly preferably a closed channel, and has a larger diameter than the external diameter of the ignition cable (3).
5. A spark plug connector (1) according to any one of claims 1 to 4, characterized in that the connecting site or the connecting element (23) forms a lasting connection between the connector body (21) and the structural element (22), wherein the connection of the connector body (21) and the structural element (22) is produced by bonding, screwing, a bayonet fixing, compression and/or welding.
6. A spark plug connector (1) according to any one of the preceding claims, characterized in that the structural element (22) is composed of polyphenylene sulfide with a glass fiber proportion from 30 to 40 %, preferably 40 %.
7. A spark plug connector (1) according to any one of the preceding claims, characterized in that the structural element (22) has a cable exit on the side remote from the spark plug high voltage contact, wherein the cable exit preferably securely locks the ignition cable (3) in place and/or seals it against external influences, is particularly preferably in the form of a rubber grommet (73).
8. A spark plug connector (1) according to any one of the preceding claims, characterized in that the structural element (22) has a securing and/or mounting means to secure the structural element (22) at a point which is fixed relative to the spark plug (6), preferably at the motor, particularly preferably in or at the spark plug shaft and/or spark plug well, wherein the securing is preferably in the form of a flange (72), rubber plug and/or plastics or rubber cap (71) or rubber grommet (73).

Images