Method for producing a spark plug electrode assembly and a spark plug, spark plug electrode assembly and spark plug

Description

State of the art

[0001] The present invention relates to a method for manufacturing a spark plug electrode assembly and also to a method for manufacturing a spark plug. Furthermore, the present invention also relates to a spark plug electrode assembly and a spark plug manufactured using the spark plug electrode assembly.

[0002] During spark plug manufacturing, the center electrode and the ground electrode are manufactured separately and installed one after the other, as is known, for example, from US 2002 / 0055318 A, US 2013 / 0006122 A, and US 2013 / 0002122 A. This means that the center electrode is connected to an electrical connection area, and the ground electrode is usually connected to the spark plug housing. Due to this separate manufacturing and arrangement of the electrodes, setting a precise distance between the electrodes, which is essential for efficient and consistently good spark generation, is difficult.

[0003] The manufacture of a spark plug arrangement is known, for example, from EP 2621038 A. Disclosure of the invention

[0004] The method according to the invention as claimed in claim 1 provides a method for producing a spark plug electrode arrangement which enables the production of a spark plug with a precisely predefined distance between the ground electrode and the center electrode.

[0005] According to the method, a spark plug electrode arrangement is produced with a ground electrode and a center electrode. This also includes the possibility of providing multiple ground electrodes and / or multiple center electrodes. The ground electrode and the center electrode are connected to one another by a connecting region formed between the ground electrode and the center electrode. The connecting region stabilizes the distance between the ground electrode and the center electrode. The electrode distance is therefore not determined subsequently by arranging the electrodes on a spark plug base body, but rather in advance due to the design of the spark plug electrode arrangement. For this purpose, the ground electrode, the center electrode, and the connecting region are formed from a one-piece spark plug electrode base body made of spark plug electrode material.The ground electrode, center electrode, and connecting area are thus formed as a single, continuous piece. In other words, the spacing between the electrodes is determined by the component geometry of the spark plug electrode assembly, not by the separate arrangement of the electrodes during spark plug assembly. This makes it possible to precisely and evenly design the electrode spacing of all center electrodes and all ground electrodes, and thus all spark gaps, without significant technical effort.

[0006] The spark plug electrode base body is not specifically limited and may have any shape and layer thickness suitable for forming at least one ground electrode, at least one center electrode and a connecting region.

[0007] Likewise, the spark plug electrode material is essentially unlimited. Nickel has proven particularly suitable as a base material because of its high temperature resistance, oxidation resistance, and wear resistance. The spark plug electrode material thus advantageously comprises at least 50 mass% nickel. According to the invention, the spark plug electrode material consists of a nickel-chromium alloy or a nickel-yttrium alloy.

[0008] The subclaims show preferred developments of the invention.

[0009] The ground electrode, the center electrode and the connecting region can be manufactured in different ways as long as these components of the spark plug electrode assembly are formed in one piece and thus from a continuous material.

[0010] According to an advantageous development, the formation of the ground electrode, the center electrode, and the connecting region includes a step of removing spark plug electrode material from the spark plug electrode base body. This is technically very simple and can be carried out in a short time and enables the geometrically and dimensional-technically precise formation of the components of the spark plug electrode assembly.

[0011] Furthermore, the method can advantageously also provide a step of forming an ignition spark gap between the ground electrode and the center electrode. According to this embodiment, the ignition spark gap is also advantageously formed by removing spark plug electrode material from the spark plug electrode base body, with the ground electrode and the center electrode remaining connected to one another by the connecting region consisting of the spark plug electrode material. The ignition spark gap thus acquires a specific geometric shape, which is necessary for the permanent, good formation of an ignition spark. By removing spark plug electrode material, the ignition spark gap can be easily adapted and formed in a predetermined shape and position to suit the conditions in the engine compartment without significant technical effort.In particular, the spark gap between all ground electrodes and center electrodes can be adjusted as desired in the radial direction perpendicular to the longitudinal axis of the spark plug.

[0012] In principle, any suitable method can be used to remove the spark plug electrode material from the spark plug electrode base body. Removal by punching, ablation, erosion, or laser cutting is particularly simple, cost-effective, and precise. These methods are therefore particularly preferred, either individually or in combination.

[0013] In order to cost-effectively create a desired three-dimensional configuration of the ground electrode, the center electrode, and the connecting region by saving spark plug electrode material, the method can further advantageously include a step of deep-drawing at least one region of the spark plug electrode base body. Thus, individual subregions can be selectively formed by deep-drawing and thus acquire the desired shape.

[0014] As an alternative or in addition to removing spark plug electrode material from the spark plug electrode base body, the ground electrode, the center electrode, and the connecting region connecting the ground electrode and the center electrode can be formed integrally by a step of building up spark plug electrode material. For this purpose, the spark plug electrode material can be deposited, for example, on a suitable carrier such that the ground electrode, the center electrode, and the connecting region are formed integrally and thus connected. The carrier can be removed after completion of the one-piece spark plug electrode arrangement. Suitable material-building processes, such as CVD or PVD, are known from the prior art. A further advantage of this embodiment is that a three-dimensional spark plug electrode arrangement can be obtained through the material build-up without further forming steps.This saves time and costs in the production of the spark plug electrode assembly.

[0015] 3D printing is particularly easy and allows for the construction of the spark plug electrode material while adhering to precise geometric specifications. The shape and design of the spark plug electrode assembly can be defined in advance using a CAD process, allowing for a precise, dimensionally accurate construction of the spark plug electrode assembly.

[0016] A further advantageous development is characterized in that the ground electrode surrounds the center electrode at least in sections. This allows the ignition spark gap to be precisely formed and the ignition spark formation to be precisely controlled locally. The ground electrode can advantageously be in the form of a cylindrical ring around the center electrode, with the center electrode further advantageously being in the form of a cylinder. The cylindrical ring and the cylinder are connected to each other by the connecting area. Due to the lack of corners, erosion wear and material removal due to the ignition spark formation can be prevented.

[0017] The connecting region is also advantageously designed in the form of at least one web that connects the ground electrode and the center electrode. A web, with a small geometric dimension, offers a very good option for stabilizing the distance between the ground electrode and the center electrode and can be easily implemented both by removing spark plug electrode material from the spark plug electrode base body and by building up spark plug electrode material.

[0018] To improve the stabilization of the gap between the ground electrode and the center electrode, the connecting area comprises two to four ridges that connect the ground electrode and the center electrode. The higher the number of ridges, the more stable the electrode gap can be. However, a number of more than four ridges can be more difficult to implement and can be a hindrance to further processing of the spark plug electrode assembly. Therefore, a number of two to four ridges has proven optimal.

[0019] To improve the wear resistance of the spark plug electrodes, it is further advantageous if one of the electrodes or even both electrodes have at least one precious metal in the region of the spark gap. The method thus advantageously comprises a step of arranging at least one first precious metal on the ground electrode and / or at least one second precious metal on the center electrode, wherein the first precious metal and / or the second precious metal are arranged such that they are arranged in a region forming a spark gap between the ground electrode and the center electrode. The precious metal can be applied directly to the corresponding electrode regions or arranged in the form of a precious metal body, such as a precious metal pin or a precious metal plate or a precious metal cylinder, in the corresponding electrode region.If both the ground electrode and the center electrode are provided with precious metal, the spark gap is formed between the first precious metal of the ground electrode on one side and the second precious metal of the center electrode on the other side.

[0020] To improve the distribution of gas flows in the combustion chamber of the spark plug, the method for producing a spark plug electrode assembly can further comprise a step of providing openings in the ground electrode and / or in the center electrode. One or more openings are advantageously provided. Through the openings, the electrodes can be better flushed with fuel gas, oxygen, or air, for example, and exhaust air can be more effectively removed from the electrodes after combustion of the fuel gas. This can increase the efficiency of ignition spark formation and improve the performance of a spark plug produced with the spark plug electrode assembly produced according to the invention.

[0021] Furthermore, the invention also describes a method for producing a spark plug. The spark plug comprises a spark plug electrode assembly with a ground electrode and a center electrode, which are connected to one another by a connecting region, and made of a one-piece spark plug electrode base body made of spark plug electrode material. The spark plug electrode assembly can be manufactured as described above. In the production of the spark plug according to the invention, a step of connecting the spark plug electrode assembly to a spark plug base body is also provided.

[0022] The spark plug base body can comprise a housing, an electrical connection area for the center electrode, and an insulator. Since details of spark plug base bodies are familiar to those skilled in the art, further explanations are omitted here.

[0023] By forming the ground electrode, the center electrode, and a connecting area connecting the two electrodes in a single piece from a single-piece spark plug electrode base body made of spark plug electrode material, a specific electrode gap is automatically realized based on the predetermined component geometry of the spark plug electrode arrangement. This gap is permanently fixed and does not require laborious and complex adjustment after the electrodes have been arranged on the spark plug base body. The method for producing a spark plug according to the invention enables a spark plug with a permanently high power density to be produced cost-effectively and with minimal technical complexity.

[0024] A permanently good arrangement of the electrodes without the possibility of generating electrical short circuits can be advantageously achieved by further developing the design in which the ground electrode is connected to a spark plug housing and / or the center electrode is connected to an electrical connection for the center electrode. This also permanently and securely attaches the electrodes to the spark plug body, which contributes to the mechanical stability of the spark plug being manufactured.

[0025] The joining is preferably carried out by means of a material bond, although the specific method for the material bond is not restricted. Due to the excellent and stable bond formation, joining can be carried out by laser welding, resistance welding, or brazing, which is particularly advantageous.

[0026] In order to suppress electrical short circuits between the ground electrode and the center electrode, the method can further comprise a step of removing the connection region between the ground electrode and the center electrode. The removal can be carried out, for example, by milling, ablation, eroding or by treatment with a laser. The removal of the connection region is carried out in particular in such a way that no material residues of the connection region protrude from the ground electrode or the center electrode, so that the spark gap between the electrodes is not impaired. The respective surfaces of the center electrode and the ground electrode are thus flat. If a first precious metal or a second precious metal is arranged on the ground electrode and / or the center electrode, the removal of the connection region can be carried out down to the surface of the respective precious metal in order to avoid notches orCreating recesses in the precious metal, which can lead to the formation of false sparks. The opposing surfaces of the first precious metal and the second precious metal are thus also flat. However, the removal of the connecting region is preferably carried out in such a way that the connecting region arranged between the first precious metal and / or the second precious metal is also at least partially removed. This leads to at least the formation of exposed corners on the respective precious metal, at which field peaks in the electric field are present, so that the ignition voltage required for the ignition spark formation is reduced. The connecting region between the respective precious metals can also be completely removed.

[0027] As already described above for the method for manufacturing a spark plug electrode assembly, the method for manufacturing a spark plug can also include a step of providing openings in the ground electrode and / or in the center electrode, wherein the openings serve to improve the distribution of the reaction gases and exhaust gases. The openings can thus be provided during the manufacture of the spark plug electrode assembly, or even during the manufacture of the spark plug, in order to better meet customer requirements. Corresponding openings can also be provided at both times.

[0028] Furthermore, the invention also describes a spark plug electrode assembly suitable for installation in a spark plug. The spark plug electrode assembly according to the invention comprises a ground electrode and a center electrode, which are connected to one another by a connecting region. The spark plug electrode assembly is formed integrally from a spark plug electrode material, so that the ground electrode, the center electrode, and the connecting region are made in one piece and thus from the same material without any step or subsequent assembly. As a result, the distance between the electrodes required for the formation of a stable ignition spark results directly from the component geometry of the spark plug electrode assembly. Likewise, a predefined ignition spark gap is provided, which allows precise local control of the ignition spark formation.Due to its one-piece design, the spark plug electrode assembly according to the invention is compact and easy to store, transport, and install. The connecting area is preferably removed only after the spark plug electrode assembly has been installed with the spark plug.

[0029] The spark plug electrode assembly according to the invention can be manufactured by the method according to the invention for producing a spark plug electrode assembly. Consequently, the respective advantages, advantageous effects, and refinements are also mutually applicable.

[0030] According to an advantageous development, the center electrode is cylindrical and / or the ground electrode is designed in the form of a cylindrical ring and / or the connecting region is formed from at least one, preferably from two to four, webs. The cylindrical shape of the center electrode or the ground electrode can prevent interference sparks. The ground electrode preferably completely surrounds the center electrode. One or more webs serve to stabilize the arrangement of the ground electrode and the center electrode, with at least two webs being preferred for stability reasons and a maximum of four webs for production reasons.

[0031] The invention also provides a spark plug manufactured by the method for manufacturing a spark plug described above. Due to the one-piece manufacturing method of the ground electrode, the center electrode, and the connecting region connecting the two electrodes, a permanently stable electrode gap can also be achieved in the spark plug according to the invention. The connecting region is then removed before the spark plug is used.

[0032] Furthermore, the invention also discloses a spark plug according to the features of claim 22.

[0033] The spark plug is characterized by high wear resistance and good spark formation due to the precious metal provided on one or more electrodes. The first precious metal has at least one section that is free of the first precious metal. Alternatively or additionally, the second precious metal has at least one section that is free of the second precious metal. Alternatively or additionally, the second precious metal has at least one section that is free of the second precious metal. The existing sections can contain spark plug electrode material, so that the surface of the respective precious metal is flat.

[0034] These precious metal-free sections result from the fact that the spark plug can be produced as described above using the method for producing a spark plug according to the invention. As explained in the description of this method, a spark plug electrode arrangement is first produced in which the ground electrode and the center electrode are connected to one another by a connecting region. Since then, i.e. only subsequently, after the electrodes and the connecting region have been formed, a first precious metal is applied to one or more regions of the ground electrode and / or a second precious metal is applied to one or more regions of the center electrode, with the respective precious metal being arranged in the spark gap between the ground electrode and the center electrode, the partial regions of the ground electrode or the center electrode that have the connecting region cannot comprise any precious metal.Thus, depending on the number of webs removed during the spark plug manufacturing process, a corresponding number of precious metal-free sections results on the ground electrode or the center electrode. Depending on how far the connecting region surrounded by precious metal is removed, these sections can comprise the same spark plug electrode material from which the spark plug electrode base body, which comprises the ground electrode, the center electrode, and the connecting region, is formed. Preferably, however, the removal of the connecting region is carried out in such a way that the connecting region arranged between the first precious metal and / or the second precious metal is also at least partially removed.This leads to exposed areas between the first precious metal and / or the second precious metal and resulting corners on the respective precious metal, at which field peaks in the electric field are present, so that the ignition voltage requirement for the ignition spark formation is reduced.

[0035] This spark plug, which is also according to the invention, is characterized by a permanently stable geometric arrangement of the electrodes and thus a precisely formed spark gap as well as high wear resistance and thus a long service life. Short description of the drawing

[0036] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Figure 1 shows a partial sectional view of a spark plug according to a first embodiment, Figure 2 shows a sectional view of a spark plug according to a second embodiment, and Figure 3 shows a cross section through a spark plug electrode arrangement according to a third embodiment. Embodiments of the invention

[0037] The figures depict only the details essential to the invention. All other details have been omitted for clarity. Furthermore, identical reference numerals refer to identical components.

[0038] As from Figure 1 As can be seen, the spark plug 1 comprises a ground electrode 2, a center electrode 3, and an insulator 4. A housing 5 at least partially surrounds the insulator 4. A thread 6 is arranged on the housing 5, which is designed for fastening the spark plug 1 in a cylinder head 7. To generate an ignition spark, the center electrode 3 is connected to an electrical connection 8.

[0039] In the spark plug 1 from Figure 1 the ground electrode 2 and the center electrode 3 are formed from the same material, namely in such a way that the ground electrode 2 and the center electrode 3 are first connected to one another by a connecting region and formed from a one-piece spark plug electrode base body made of spark plug electrode material, for example by deep drawing the spark plug electrode base body.

[0040] A first precious metal 12 is then arranged on the ground electrode 2 and a second precious metal 13 is arranged on the center electrode 3, wherein a spark gap F is formed between the first precious metal 12 and the second precious metal 13.

[0041] In a further step, the spark plug electrode base body is connected to a spark plug base body 9 which, as shown here, comprises the housing 5, the insulator 4 and the electrical connection 8.

[0042] As shown here, the ground electrode 2 is preferably connected to the housing 5 by a first weld S1, and the center electrode 3 is advantageously connected to the electrical terminal 8 by a second weld S2. The connection area initially formed between the ground electrode 2 and the center electrode 3 was removed for commissioning the spark plug 1.

[0043] Due to the fact that the ground electrode 2 and the center electrode 3 as well as the noble metals 12, 13 arranged thereon are produced by forming a connecting region between the ground electrode 2 and the center electrode 3, in the Figure 1In the spark plug 1 shown, the electrode gap between the first precious metal 12 of the ground electrode 2 and the second precious metal 13 of the center electrode 3 is permanently stable and very precisely adjusted to a predetermined distance. The spark plug 1 is therefore characterized by high power density and low spark erosion wear.

[0044] Figure 2shows a partial section of a spark plug 1 according to a second embodiment. The ground electrode 2 is in the form of a roof electrode and projects beyond the center electrode 3. At the combustion chamber-side end of the center electrode 3, the center electrode 3 has a second precious metal 13, which is in the form of a cuboid or cylindrical plate. Opposite this, on the ground electrode 2, a first precious metal 12, also in the form of a cuboid or cylindrical plate, is arranged. The spark gap F is formed between the first precious metal 12 and the second precious metal 13. This is where the ignition spark is generated. The first precious metal 12 has a precious metal-free section 14, and the second precious metal 13 has a precious metal-free section 20.

[0045] The noble metal-free sections 14, 20 result from the production of the spark plug 1. For the production of the spark plug 1 according to the second embodiment, a spark plug electrode assembly, which has a ground electrode 2, a center electrode 3, and a connecting region 11 and is formed in one piece, is connected to a spark plug base body. The spark plug electrode assembly is formed from a one-piece spark plug electrode base body made of spark plug electrode material. The connecting region 11 is in Figure 2 shown in dashed lines.

[0046] A spark plug electrode base body 15 to be used for this purpose can, for example, be cuboid-shaped or fully cylindrical. A possible contour of such a spark plug electrode base body 15 is shown in Figure 2shown in dashed lines. The spark plug electrode material preferably comprises nickel as the main element and consists in particular of a nickel-chromium alloy or a nickel-yttrium alloy.

[0047] The ground electrode 2, the center electrode 3, and a connecting region 11 connecting the ground electrode 2 and the center electrode 3 can be formed from the spark plug electrode base body 15, for example, by removing spark plug electrode material. The removal of spark plug electrode material can be carried out particularly well by an abrasive process, by erosion, by laser treatment, or by punching. This can also form the spark gap F and other free regions 16 between the ground electrode 2 and the center electrode 3. The connecting region 11 is formed between the combustion chamber-side end of the center electrode 3 and the region of the ground electrode 2 opposite the combustion chamber-side end of the center electrode 3.

[0048] The ground electrode 2, the center electrode 3, and the connecting region 11 are thus formed integrally from the same material. In a further process step, the first precious metal 12 is applied to the ground electrode 2 and the second precious metal 13 to the center electrode 3, so that the first precious metal 12 and the second precious metal 13 lie opposite each other in the region of the spark gap. Only in a step following this process step is the connecting region 11 between the ground electrode 2 and the center electrode 3 removed. This leaves a precious metal-free section 20 on the center electrode 3 and a precious metal-free section 14 on the ground electrode 2. The precious metal-free sections 14, 20 can contain spark plug electrode material, provided the spark plug electrode material of the previous connecting region was not also removed in these regions.

[0049] Figure 3shows a spark plug electrode assembly 10 according to a third embodiment of the invention. The spark plug electrode assembly 10 comprises a center electrode 3, which is surrounded by a ground electrode 2 in a ring-cylindrical manner. The center electrode 3 and the ground electrode 2 are connected to one another by a connecting region 11. The spark plug electrode assembly 10 is made from a one-piece spark plug electrode base body, so that in the spark plug electrode assembly 10, the ground electrode 2, the center electrode 3, and the connecting region 11 are also formed in one piece, i.e., from the same material without any steps or connecting seams.

[0050] An exemplary method for producing the ground electrode 2, the center electrode 3, and the connecting region 11 includes a step of removing spark plug electrode material from the spark plug electrode base body. The spark plug electrode base body can be Figure 3In the embodiment shown, for example, they may have a fully cylindrical shape with a diameter A. The diameter A is preferably at most as large as the inner diameter of the housing of the spark plug in which the spark plug electrode arrangement 10 is to be installed, so that a precise fastening of the spark plug electrode arrangement 10 is easily possible.

[0051] By removing spark plug electrode material, four free areas 16 are created, which are to be assigned to the spark gap F.

[0052] As an alternative to the method described above, the ground electrode 2, the center electrode 3 and the connecting region 11 can also be formed in one piece by building up spark plug electrode material, for example by using a 3D printing process.

[0053] In the present embodiment, the connecting area 11 consists of four webs 11a, each of which is arranged at a 90° angle to one another.

[0054] A first precious metal 12 is arranged on the inner surface 17 of the ground electrode 2 facing the center electrode 3. A second precious metal 13 is arranged on the outer surface 18 of the center electrode 3 facing the ground electrode 2. The first precious metal 12 and the second precious metal 13 are not arranged in the connection region 11.

[0055] The spark gap F is formed between the first precious metal 12 and the second precious metal 13.

[0056] To manufacture a spark plug using the spark plug electrode assembly 10 shown here, the connecting region 11, consisting of the four webs 11a, is removed. For example, sections 19 of the webs can be removed so that the ground electrode 2 and the center electrode 3 are no longer electrically connected. The sections 19 are located between the first precious metal 12 and the second precious metal 13 in the free space 16. By removing the sections 19, sections 14 that are free of precious metal but contain spark plug electrode material remain on the ground electrode 2, and sections 20 that are free of precious metal but contain spark plug electrode material remain on the center electrode 3. These sections 20 accordingly penetrate the first precious metal 12 and the second precious metal 13.

[0057] Preferably, the removal of the connecting region 11 is carried out in such a way that the connecting region 11 arranged between the first precious metal 12 and the second precious metal 13 is also at least partially removed. Thus, as in Figure 3 As shown, a section 21 is removed. This leads to the formation of free spaces between the first precious metal 12 on one side and the second precious metal 13 on the other side, and further to exposed corners 22 of the first precious metal 12 and exposed corners 23 of the second precious metal 13, at which field peaks in the electric field are present, so that the ignition voltage requirement for the ignition spark formation can be reduced.

[0058] After removing the connecting region 11, the center electrode 3 has a fully cylindrical shape and the ground electrode 2 has the shape of a cylindrical ring.

[0059] By providing the connecting region 11 and the one-piece design of the ground electrode 2, the center electrode 3, and the connecting region 11, the geometric design of the spark plug electrode assembly 10 results in a fixed and precisely predeterminable electrode spacing, which, after the application of the first precious metal 12 and the second precious metal 13, also results in a precisely formed spark gap F. A spark plug manufactured using the spark plug electrode assembly 10 according to the invention is characterized by a high power density and low spark erosion wear.

Claims

1. Method for manufacturing a spark plug electrode arrangement (10) having an earth electrode (2) and a centre electrode (3) which are connected to each other by a connecting region (11), characterized in that the earth electrode (2), the centre electrode (3) and the connecting region (11) are formed from a one-piece spark plug electrode base body (15) made of spark plug electrode material, wherein the spark plug electrode material is a nickel-chromium alloy or a nickel-yttrium alloy.

2. Method according to Claim 1, wherein the forming of the earth electrode (2), the centre electrode (3) and the connecting region (11) comprises a step of removing spark plug electrode material from the spark plug electrode base body (15).

3. Method according to Claim 2, comprising a step of forming an ignition spark gap (F) between the earth electrode (2) and the centre electrode (3) by removing spark plug electrode material from the spark plug electrode base body (15), wherein the earth electrode (2) and the centre electrode (3) remain connected to each other by the connecting region (11) consisting of the spark plug electrode material.

4. Method according to Claim 2 or 3, wherein the spark plug electrode material is removed from the spark plug electrode base body (15) by punching or ablating or eroding or lasers.

5. Method according to one of Claims 2 to 4, further comprising a step of deep-drawing at least one region of the spark plug electrode base body (15).

6. Method according to Claim 1, comprising a step of constructing spark plug electrode material in such a way that the earth electrode (2), the centre electrode (3) and the connecting region (11) connecting the earth electrode (2) and the centre electrode (3) are formed in one piece.

7. Method according to Claim 6, wherein spark plug electrode material is constructed in such a way that an ignition spark gap (F) is formed between the earth electrode (2) and the centre electrode (3), wherein the earth electrode (2) and the centre electrode (3) remain connected to each other by the connecting region (11) consisting of the spark plug electrode material.

8. Method according to Claim 6 or 7, wherein the spark plug electrode material is constructed by 3D printing.

9. Method according to one of the preceding claims, wherein the earth electrode (2) surrounds the centre electrode (3) at least in sections.

10. Method according to one of the preceding claims, wherein the connecting region (11) is designed in the form of at least one bar which connects the earth electrode (2) and the centre electrode (3) to each other.

11. Method according to Claim 10, wherein the connecting region (11) is designed in the form of two to four bars which connect the earth electrode (2) and the centre electrode (3) to each other.

12. Method according to one of the preceding claims, further comprising a step of arranging at least a first precious metal (12) on the earth electrode (2) and / or at least a second precious metal (13) on the centre electrode (3), wherein the first precious metal (12) and / or the second precious metal (13) are arranged in such a way that they are arranged in a region forming a spark gap (F) between the earth electrode (2) and the centre electrode (3).

13. Method according to one of the preceding claims, further comprising a step of making openings in the earth electrode (2) and / or in the centre electrode (3).

14. Method for manufacturing a spark plug (1), wherein the spark plug comprises a spark plug electrode arrangement (10) manufactured according to one of Claims 1 to 13 and a spark plug base body, characterized in that the method for manufacturing a spark plug (1) comprises a step of connecting the spark plug electrode arrangement (10) to a spark plug base body (9).

15. Method according to Claim 14, wherein the earth electrode (2) is connected to a housing (5) of the spark plug (1) and / or the centre electrode (3) is connected to an electrical connection (8) for the centre electrode (3).

16. Method according to Claim 14 or 15, wherein the connecting is carried out by means of laser welding, by means of resistance welding or by means of brazing.

17. Method according to one of Claims 14 to 16, comprising a step of removing the connecting region (11) between the earth electrode (2) and the centre electrode (3).

18. Method according to one of Claims 14 to 17, comprising a step of making openings in the earth electrode and / or in the centre electrode (3).

19. Spark plug electrode arrangement comprising an earth electrode (2) and a centre electrode (3) which are connected to each other by a connecting region (11), characterized in that the earth electrode (2), the centre electrode (3) and the connecting region (11) of the spark plug electrode arrangement (10) are formed in one piece from a spark plug electrode material, wherein the spark plug electrode material is a nickel-chromium alloy or a nickel-yttrium alloy.

20. Spark plug electrode arrangement according to Claim 19, wherein the centre electrode (3) has a cylindrical design and / or wherein the earth electrode (2) is designed in the form of a cylindrical ring and / or wherein the connecting region (11) is formed of at least one bar, preferably of two to four bars.

21. Spark plug manufactured according to a method according to one of Claims 14 to 18.

22. Spark plug comprising an earth electrode (2) and a centre electrode (3) which define a spark gap (F) therebetween, wherein the earth electrode (2) surrounds the centre electrode (3), wherein the earth electrode (2) and the centre electrode (3) are formed from an originally one-piece spark plug electrode base body made of spark plug electrode material, wherein the spark plug electrode material is a nickel-chromium alloy or a nickel-yttrium alloy, wherein a first precious metal (12) is arranged on the earth electrode (2) in a region forming a spark gap (F) between the earth electrode (2) and the centre electrode (3) and wherein the earth electrode (2) has, in that region, at least one section (14) which is free of first precious metal (12) and / or wherein a second precious metal (13) is arranged on the centre electrode (3) in a region forming a spark gap (F) between the earth electrode (2) and the centre electrode (3) and wherein the centre electrode (3) has, in that region, at least one section (20) which is free of second precious metal (13).