EP1265329B1 - Spark plug of an internal combustion engine - Google Patents

Abstract

A spark plug of an internal combustion engine, in particular for use in Otto-cycle gas engines, comprising an insulator body, a base central electrode, at least one ground electrode and at least one swirl chamber, wherein the electrodes of the spark plug are surrounded by a wall, which in particular is in the form of a surface of a cylinder, of the swirl chamber, wherein at least one ground electrode carrier arrangement (8) with a plurality of inwardly facing, preferably flat ground electrodes (9) or a plurality of ground electrode carriers (6) each with inwardly facing, preferably flat ground electrodes (9) is or are arranged at the wall (13) of the swirl chamber (3).

Description

The present invention relates to a spark plug of an internal combustion engine, especially for use in gasoline engines, with an insulator body, a Base center electrode, at least one ground electrode and at least one Whirl chamber, wherein the electrodes of the spark plug of one, in particular Cylinder shell-shaped, wall of the vortex chamber are surrounded. Furthermore The invention relates to a method for producing a spark plug.

Currently available spark plugs for industrial gas engines are in many cases products derived from the automotive industry and by corresponding improvements for preferential use in industrial gas engines were adjusted. These candles usually have a cylindrical center electrode on, which is provided with a noble metal pin. At the ground electrodes are both variants with hook electrode as well as with two to four laterally attached Electrode fingers in use. The hook electrodes can also with a Be provided precious metal platelets. Such spark plugs are e.g. from EP 0834973 A2, EP 0859436 A1, EP 1049222 A1, DE 196 41 856 A1 and WO 95/25372. The disadvantage of these spark plugs is, inter alia, essentially that the Flow conditions in the area of the ignition completely from the Depend on flow conditions in the combustion chamber of the respective cylinder. That's the way it works for example, to blow out the spark when the Flow rates of the gas-air mixture are too large.

To overcome this disadvantage, it is known from the documents US 5,554,908 A, US 2,776,394 A and FR 2,131,938 A according to the preamble of claim 1, already known, the electrodes of the spark plug with To surround a cylindrical vortex chamber. The one shown in US 5,554,908 A However, among other things arrangement has the disadvantage that no defined Ground electrodes are provided and the sparks are between the Center electrodes and any point on the ground electrode Spread vortex chamber. In US Pat. Nos. 2,776,394 A and 2,131,938 A spark plug shown has the disadvantage that only one or two small-area ground electrodes are present, which are relatively short Have lifetimes and by wear or contamination quickly become unusable.

Object of the present invention is thus to provide a spark plug with a Vortex chamber as well as to provide a method for its manufacture in which the above described disadvantages of the prior art are eliminated.

This is inventively achieved in that at least one Ground electrode support assembly with a plurality of inwardly facing, preferably flat, ground electrodes or multiple ground electrode carrier with each after inside pointing, preferably flat, ground electrodes on the wall of the Swirl chamber is arranged or are.

By enclosing the electrode area by means of a vortex chamber, the Ignition point controlled flow and turbulence conditions of the fuel-air mixture be effected. This ensures that at the ignition one for the Ignition and ignition optimum flow velocity and turbulence the fuel-air mixture is present. This leads to an optimized and fast Combustion of the fuel-air mixture in the combustion chamber of the cylinder and thus to an optimal and environmentally friendly energy yield of the internal combustion engine. According to the invention by the arrangement of a ground electrode carrier assembly or more ground electrode carrier to the vortex chamber ensures that a plurality of sparks are generated simultaneously and these to the other along defined spark gaps. This increases both the service life as also the reliability of the spark plug.

It is particularly advantageous in this case that the wall of the vortex chamber openings for Passage of fuel-air mixture has. These openings are like this designed to allow good mixture access.

In the sense of optimum ignition of the entire located in the combustion chamber Fuel-air mixture, it is particularly advantageous that the combustion chamber end the wall of the vortex chamber has an opening, or is completely open. Favorable variants of the openings in the wall of the vortex chamber provide that they are formed as a hole (s) or slot (s) and / or polygon (s) and / or ellipse (s) is (are).

In the sense of an optimal influencing of the flow velocities of the Fuel-air mixture in the region of the ignition, it is particularly favorable that the combustion chamber-side end of the wall of the vortex chamber via the electrodes protrudes.

To allow a corresponding voltage build-up or current flow is the Wall of the vortex chamber electrically conductive and electrically conductive with a, preferably threaded threaded housing lower part is connected. This ensures that the ground electrodes on the Ground electrode support or the ground electrode support assembly and over the Wall of the vortex chamber and the conductive spark plug housing are grounded.

Favorable embodiments provide that the ground electrode or the ground electrode support assembly on the wall of the vortex chamber are welded (is). Alternatively, it can also be provided that the Ground electrode carrier arrangement as an integrated component, preferably in a ring-like manner the wall of the vortex chamber is integrated. Here, the term denotes Ground electrode carrier assembly an array of several Ground electrode carriers on which in turn at least one Ground electrode is arranged. Favorable embodiments of the Ground electrode support arrangements provide that at least one Ground electrode support assembly preferably four perpendicular to each other having arranged planar ground electrodes. Particularly favorable in the production and durability is that the vortex chamber together with the In one piece, ground electrode carriers or the ground electrode carrier assembly is trained.

As a counterpart to this type of ground electrode support assembly or the Ground electrode carriers, it is particularly advantageous that the spark plug at least a center electrode carrier, preferably four perpendicular to each other arranged, flat, preferably outwardly facing center electrodes on Center electrode supports are arranged. Here, the center electrode carrier again have one or more fingers or single-centered electrode carrier, wherein the Fingers or single-center electrode carriers, in turn, each at least one Center electrode is arranged. In favorable training forms is at achieves this combination that the electrodes of the center electrode carrier and the Ground electrode carrier or the ground electrode carrier assembly in pairs plane-parallel opposite, an insulating air gap between each other having, are arranged. Here, referring to the Total component size reaches very long electrode erosion edges. This carries Significantly to improve the life of the spark plug.

A favorable variant also provides that the wall of the vortex chamber is manufactured as an integral part of the housing base. Another preferred Embodiment provides that the vortex chamber in the region of at least one Mass electrode carrier and / or at least one ground electrode carrier assembly at least one exemption to readjust the ground electrode carrier and / or the mass electrode support assembly and / or the ground electrode has. By this possibility of readjustment of the electrodes will increase the life of the Spark plug further improved. In addition, an adaptation of the Electrode distance to different operating parameters possible. In addition, too be provided that the center electrode carrier is designed to be adjustable.

A particularly favorable method for producing a spark plug according to the above mentioned features provides that the wall of the vortex chamber with at least a ground electrode and / or at least one ground electrode carrier and / or with at least one ground electrode carrier assembly and / or the Center electrode carrier manufactured individually and then to commercially available Spark plugs are attached. This method according to the invention makes it possible thus, inexpensive standard industrial spark plugs as commercially available from various spark plug manufacturers are offered to use. Because of this Manufacturing method, a spark plug according to the invention of many various standard industrial spark plug types. Furthermore is a cost-effective production of very many different spark plugs possible.

In this method, it is particularly favorable that the wall of the vortex chamber at least one ground electrode of a commercial spark plug by means of pulsed and / or continuous laser welding process and / or Electrode beam welding and / or soldering and / or Resistance welding process is welded. It is beyond that favorable, that the center electrode carrier on at least one base center electrode of the Insulator body of a standard commercial spark plug by means of pulsed and / or continuous laser welding process and / or Electrode beam welding and / or soldering and / or Resistance welding process is welded.

Further features and details of the present invention will become apparent from the following figure description:

Fig. 1 eine Standardindustriezündkerze mit erfindungsgemäßer Wirbelkammer,

Fig. 2, 3 und 4 perspektivische Ansichten der erfindungsgemäßen Wirbelkammer aus Richtung des Brennraums,

Fig. 5 eine seitliche Ansicht auf die erfindungsgemäße Wirbelkammer mit Freistellungen und

Fig. 6 eine perspektivische Seitenansicht auf den Mittelelektrodenträger, wobei die erfindungsgemäße Wirbelkammer entfernt ist.

Showing:

1 shows a standard industrial spark plug with vortex chamber according to the invention,

2, 3 and 4 are perspective views of the vortex chamber according to the invention from the direction of the combustion chamber,

Fig. 5 is a side view of the vortex chamber according to the invention with exemptions and

Fig. 6 is a side perspective view of the center electrode carrier, wherein the vortex chamber according to the invention is removed.

In the illustrated in Fig. 1 spark plug with swirl chamber 3 is on a Standard industrial spark plug as commercially available from various spark plug manufacturers is offered.

On the lower housing part 4, a vortex chamber 3 is mounted on the motor side, wherein whose combustion chamber side end 15 is open. In the specific case, for reasons of Temperature and hot corrosion resistance an open vortex chamber 3 with a Wall 13 made of Inco Alloy 600 (WNr 2.4816) by laser at the weld seam 7 am Housing base 4 welded. As alternatives can also others Nickel base alloys or high temperature stainless steels for the wall 13 to Use come. The vortex chamber 3 is alternatively also in one piece so as integral part of the housing base 4 made.

The wall 13 of the vortex chamber 3 has openings 2, which is a good Enable mixture access. The openings 2 can be used as bores, slots, Polygons or ellipses or similar shape.

Integrating part of the vortex chamber according to the invention are the 4th Ground electrode carrier 6. The vortex chamber 3 and the ground electrode carrier 6 can be made in one piece. However, it is also possible rectangular To weld metal cuboid 5 as a ground electrode carrier 6 in the vortex chamber (Fig. 3). This can also be done by welding a Masseelektrodentrageranordnung 8 take place. This is in Fig. 4 as an annular Arrangement 8 shown.

In the region of the ground electrode carrier, the wall 13 of the vortex chamber 3 a or several exemption (s) 12, whereby it is possible, the Masseelektrodentrager 6 or the ground electrode support assembly 8 nachstellt (Figure 5).

The ground electrode supports 6 are provided with noble metal platelets as ground electrodes 9 provided, these are by laser on one side or both sides with the carrier. 6 welded. The weld is mounted so that at the electrode sides of the Gap is closed. That is, between precious metal platelets 9 and Ground electrode carrier 6 is not an open gap (or opening) through which gas can occur.

By this construction, it is possible in terms of the overall component size very much produce long electrode ablation edges. There are as ground electrodes 9 Precious metal flakes with an edge length of greater than 4.0 mm used. in the illustrated embodiment, the edge length is 6.25 mm.

In the ground electrodes 9 come in the illustrated embodiment Precious metal plates with the dimensions 6.25 x 1.6 x 0.5 mm (it can also other dimensions are used) are used. As the noble metal, e.g. a Alloy of Pt Rh alloys (90/10, 95/5, 80/20, 75/25) can be used.

The welding process can be pulsed lasers, continuous lasers (CW lasers), Electron beam welding or vacuum and high vacuum soldering as well as the plasma welding or the resistance welding technique can be used.

As shown in Fig. 6, the base center electrode (not shown here) of the spark plug insulator 1 welded to a center electrode carrier 10. By the Center electrode carrier 10 may in coordination with the vortex chamber 3 and the Ground electrodes 6 or the ground electrode support assembly 8, the spark position be determined. The center electrode carrier 10 is placed on the base center electrode deferred until it rests flush with the Keramikmittelelektrodenisolatorsockel 14. In this position he is with the base center electrode at the welded joint 11 welded. By this arrangement, the base center electrode is high pressure safe. One Pressing out of the ceramic base due to the engine pressure is not possible since the center electrode carrier 10 welded to the base center electrode 10 Ceramic base 14 is shouldered. The welded joint 11 between Center electrode carrier 10 and base center electrode is welded by welding made of a pulsed laser. However, it can also be a continuous one working laser (CW laser), the electron beam welding process, a soldering process or the resistance welding technique can be used.

The weld 11 may be along the entire length of the base center electrode take place, so from the outside so through the center electrode carrier 10 on the Base center electrode is welded through. It can be one or more Spot welds and one or more weld seams which in Longitudinal axis if necessary several times on the circumference or radially if necessary several times on Scope can be arranged.

The center electrode carrier 10 is designed so that it has a good mixture accessibility allows. By its embodiment shown in detail in Fig. 6 is a light Adjustment possible. The center electrode carrier is designed so that Center electrode precious metal plates 17 with a length greater than 4 mm can be welded on. In the concrete invention, the edge length the center electrode support 17 6.25 mm. The center electrode carrier 10 is 4 discrete single center electrode carriers 16 to which the Edelmetallplättchen are welded as center electrodes 17. These are by means of Laser welded on one or both sides to the carrier. The weld is like that attached so that the gap is closed at the electrode sides. This means There is no open gap between precious metal plates and electrode carrier fingers (or opening) through which gas can enter.

As a material for the center electrode carrier 10 comes in the concrete case Inco Alloy 600th (No. 24816) are used. As alternatives can also others Nickel-based alloys or high-temperature stainless steels are used.

In the precious metal for the center electrodes 17 platelets come with the Dimensions 6.25 x 2.0 x 0.5 mm (other dimensions may be used be used). As the noble metal, e.g. again Pt Rh alloys (90/10, 95/5, 80/20, 75/25).

Claims (11)

1. A spark plug of an internal combustion engine, in particular for use in Otto gas engines, comprising an insulator body, a base central electrode, at least one earth electrode and at least one swirl chamber, wherein the electrodes of the spark plug are surrounded by a wall, in particular in the form of a cylindrical surface, of the swirl chamber, characterised in that at least one earth electrode carrier arrangement (8) with a plurality of inwardly facing, preferably aereal earth electrodes (9) or a plurality of earth electrode carriers (6) each with respective inwardly facing, preferably aereal earth electrodes (9) is or are arranged at the wall (13) of the swirl chamber (3).
2. A spark plug according to claim 1 characterised in that the wall (13) of the swirl chamber (3) has openings for fuel-air mixture to pass therethrough.
3. A spark plug according to one of claims 1 and 2 characterised in that the combustion chamber end of the wall (13) of the swirl chamber (3) has an opening or is completely opened.
4. A spark plug according to claim 2 or claim 3 characterised in that the opening or openings (2) is or are in the form of a bore or bores and/or slot or slots and/or polygon or polygons and/or ellipse or ellipses.
5. A spark plug according to one of claims 1 to 4 characterised in that the combustion chamber end (15) of the wall (13) of the swirl chamber (3) projects beyond the electrodes (9, 17).
6. A spark plug according to one of claims 1 to 5 characterised in that the wall (13) of the swirl chamber (3) is electrically conductive and is electrically conductively connected to a bottom housing portion (4) which preferably has a screwthread.
7. A spark plug according to one of claims 1 to 6 characterised in that the earth electrode carriers (6) or the earth electrode carrier arrangement (8) is or are welded to the wall (13) of the swirl chamber (3).
8. A spark plug according to one of claims 1 to 6 characterised in that the earth electrode carrier arrangement (8) is integrated as an integrated component part, preferably in a ring-like configuration, into the wall (13) of the swirl chamber (3).
9. A spark plug according to one of claims 1 to 6 characterised in that the swirl chamber (3) is formed in one piece together with the earth electrode carriers (6) or the earth electrode carrier arrangement (8).
10. A spark plug according to one of claims 1 to 9 characterised in that the earth electrode carrier arrangement (8) has preferably four aereal electrodes (9) which are arranged perpendicularly to each other.
11. A process for the production of a spark plug according to one of claims 1 to 10 characterised in that the wall (13) of the swirl chamber (3) with at least one earth electrode (9) and/or with at least one earth electrode carrier (6) and/or with at least one earth electrode carrier arrangement (8), and/or the central electrode carrier (10) are produced individually and are then mounted to commercially available spark plugs.

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