Spark-Ignited Reciprocating-Piston Internal-Combustion Engine With a Pre-Chamber Ignition System

Abstract

A spark-ignited reciprocating piston internal combustion engine may include a pre-chamber ignition system which is arranged in the cylinder head of the reciprocating piston internal combustion engine and in which an ignition device is arranged, comprising an ignition electrode in a housing, said ignition electrode protruding into a cavity of the pre-chamber ignition system. The cavity is covered from the combustion chamber of the reciprocating piston internal combustion engine by a cover, and the cover has at least one first opening which connects the cavity and the combustion chamber together so as to conduct gas. A metal transverse brace with at least one second opening, which connects opposite sides of the housing together, is arranged in the cavity in the region of the ignition electrode, wherein the metal transverse brace is made of a first metal material in a central region and a second metal material in a region contacting the housing.

Claims

1.-8. (canceled)

9. A spark-ignited reciprocating-piston internal-combustion engine with a pre-chamber ignition system which is arranged in a cylinder head of the reciprocating-piston internal-combustion engine, the reciprocating-piston internal-combustion engine comprising: an ignition device with an ignition electrode arranged in a housing and protruding into a cavity of the pre-chamber ignition system, wherein the cavity is covered with a cover from a combustion chamber of the reciprocating-piston internal-combustion engine, wherein the cover includes at least one first aperture which connects the cavity and the combustion chamber to one another in gas-conducting manner, wherein a metallic cross-member with at least one second aperture, which connects opposing sides of the housing, is arranged in the cavity in a region of the ignition electrode, and wherein the metallic cross-member includes a first metallic material in a central region of contact with the housing and a second metallic material in a region of contact with the housing.

10. The reciprocating-piston internal-combustion engine according to claim 9, wherein the cross-member in the contact region includes a thermally conductive metallic material.

11. The reciprocating-piston internal-combustion engine according to claim 9, wherein the cross-member in the contact region includes the same metallic material as a metallic material of the housing.

12. The reciprocating-piston internal-combustion engine according to claim 9, wherein the cross-member includes a high-temperature-resistant metallic material in the central region.

13. The reciprocating-piston internal-combustion engine according to claim 9, wherein the cross-member includes at least one of a tungsten alloy, a tungsten/copper alloy, a nickel alloy, and an Inconel material in the central region.

14. The reciprocating-piston internal-combustion engine according to claim 9, wherein the cross-member includes a ground electrode for the ignition electrode in the central region.

15. The reciprocating-piston internal-combustion engine according to claim 9, wherein the central region and the contact region are connected with a weld.

16. The reciprocating-piston internal-combustion engine according to claim 9, wherein the contact region and the housing are connected by force closure.

17. The reciprocating-piston internal-combustion engine according to claim 9, wherein the contract region and the housing are connected via positive closure.

18. The reciprocating-piston internal-combustion engine according to claim 9, wherein the contract region and the housing are connected via material closure.

19. A spark-ignited reciprocating-piston internal-combustion engine, comprising: a pre-chamber ignition system; a cylinder head, wherein the pre-chamber ignition system is arranged within the cylinder head; and an ignition electrode configured for placement in a housing of the engine and for protruding into a cavity of a pre-chamber ignition system of the engine, wherein the cavity is covered with a cover from a combustion chamber of the reciprocating-piston internal-combustion engine, wherein the cover includes at least one first aperture which connects the cavity and the combustion chamber to one another in gas-conducting manner, wherein a metallic cross-member with at least one second aperture, which connects opposing sides of the housing, is arranged in the cavity in a region of the ignition electrode, and wherein the metallic cross-member includes a first metallic material in a central region of contact with the housing and a second metallic material in a region of contact with the housing.

20. The reciprocating-piston internal-combustion engine according to claim 19, wherein the cross-member in the contact region includes a thermally conductive metallic material.

21. The reciprocating-piston internal-combustion engine according to claim 19, wherein the cross-member in the contact region includes the same metallic material as a metallic material of the housing.

22. The reciprocating-piston internal-combustion engine according to claim 19, wherein the cross-member includes a high-temperature-resistant metallic material in the central region.

23. The reciprocating-piston internal-combustion engine according to claim 19, wherein the cross-member includes at least one of a tungsten alloy, a tungsten/copper alloy, a nickel alloy, and an Inconel material in the central region.

24. The reciprocating-piston internal-combustion engine according to claim 19, wherein the cross-member includes a ground electrode for the ignition electrode in the central region.

25. The reciprocating-piston internal-combustion engine according to claim 19, wherein the central region and the contact region are connected with a weld.

26. The reciprocating-piston internal-combustion engine according to claim 19, wherein the contact region and the housing are connected by force closure.

27. The reciprocating-piston internal-combustion engine according to claim 19, wherein the contract region and the housing are connected via positive closure.

28. The reciprocating-piston internal-combustion engine according to claim 19, wherein the contract region and the housing are connected via material closure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention is elucidated in more detail in the following in a single FIGURE with reference to an embodiment.

[0026] FIG. 1 shows a top view of a section through a pre-chamber ignition system according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 shows a top view of a section through a pre-chamber ignition system 1 according to the depicted embodiment. The pre-chamber ignition system 1 has been provided for a spark-ignited reciprocating-piston internal-combustion engine. A housing 1′ of the pre-chamber ignition system 1 is arranged in a cylinder head 2 of the reciprocating-piston internal-combustion engine and consists of a metal having good thermal conductivity, such as copper or a copper alloy. In the present case, the pre-chamber ignition system 1 has been screwed into the cylinder head 2. It is also possible for the pre-chamber ignition system 1 and the cylinder head 2 to be wedged, welded or soldered together.

[0028] An ignition device 3—for instance, a spark plug with an ignition electrode 3′—has been inserted into the pre-chamber ignition system 1 from a side facing away from a combustion chamber 6 of the reciprocating-piston internal-combustion engine. Here too, a screw coupling which is not represented is again present. A corona ignition device or other ignition source is also possible. The ignition device 3 protrudes into a cavity 4 of the pre-chamber ignition system 1.

[0029] On the side facing away from the ignition device 3, the cavity 4 is covered with a cover 5 in relation to a combustion chamber 6 of the reciprocating-piston internal-combustion engine. The cover 5 exhibits at least one first aperture 7 which connects the cavity 4 and the combustion chamber 6 to one another in gas-conducting manner. In the present embodiment, two apertures 7 are discernible, only one of which is numbered. The number, size and position of the apertures 7 may vary from pre-chamber ignition system 1 to pre-chamber ignition system 1.

[0030] Furthermore, a metallic cross-member 8 with at least one second aperture 9 is arranged in the cavity 4 in the region of the ignition electrode 3′. The ignition electrode 3′ protrudes into the region of the second aperture 9. The cross-member 8 consequently subdivides the cavity 4 into a residual-gas chamber, not numbered, and a fresh-gas chamber, likewise not numbered. The residual-gas chamber extends between the ignition device 3 and the cross-member 8, and the fresh-gas chamber extends between the cross-member 8 and the cover 5.

[0031] The cross-member 8 advantageously serves as ground electrode for the ignition electrode 3′ and consequently performs the dual function of ground electrode and “space-divider”.

[0032] In accordance with the present disclosure, the metallic cross-member 8 is made of a first metallic material in a central region 10, and of a second metallic material in a region 11 of contact with the housing 1′. The cross-member 8 in the contact region 11 is preferentially made of a thermally conductive metallic material; the cross-member 8 in the contact region 11 is particularly preferably made of the same metallic material as the housing 1′. This means that the contact regions 11, just like the housing 1′, preferentially consist of copper or a copper alloy. A mechanical connection between the contact region 11 and the housing 1′ is preferably effected by force closure and/or positive closure and/or material closure; these are connection technologies that are sufficiently well-known to a person skilled in the art.

[0033] In comparison with the contact regions 11, the cross-member 8 consists in its central region 10 of a high-temperature-resistant metallic material such as, for example, a tungsten alloy or a tungsten/copper alloy or a nickel alloy or an Inconel material. This is particularly advantageous, since the cross-member 8 acts in its central region 10 as a ground electrode for the ignition electrode 3′. The central region 10 and the contact regions 11 are particularly preferably connected to one another by welding, in particular by friction welding. These connection technologies are also sufficiently well-known to a person skilled in the art.

[0034] In summary, the following may be stated:

[0035] A pre-chamber ignition is to be effected via, for instance, a CuCr1Zr (copper/chromium/zirconium alloy) housing 1′ of the pre-chamber ignition system 1. The contact regions 11 of the cross-member 8 are preferentially to be pressed into the housing 1′ of the pre-chamber ignition system 1, and, for instance, are also to have been constructed from CuCr1Zr. The actual ground electrode, constituted by the central region 10, is then located between the two CuCr1Zr contact regions 11, preferentially connected to the contact regions 11 by friction welding. This central region 10 then preferentially consists of a tungsten/copper sintered combination (W/Cu) or entirely of tungsten (W) or nickel (Ni) or Inconel (Inconel is a trade name of the company Special Metals Corporation for highly corrosion-resistant nickel-based alloys; these nickel-based alloys are utilized, above all, for high-temperature applications) or of another material, suitable for the application, that is resistant to high temperature, has high spark-out resistance and high thermal conductivity. In other words, the ground electrode then consists of several parts connected to one another by friction welding.

[0036] In conclusion, it should also be stated that the configuration of the pre-chamber ignition system 1 in accordance with the present disclosure can be employed both for passive pre-chamber ignition systems, as represented here, and for active pre-chamber ignition systems having their own introduction of fuel into the cavity 4.

[0037] In a further embodiment, the housing 1′ may also have been formed from the cylinder-head material—that is to say, the housing 1′ is then a bore in the cylinder head 2.

LIST OF REFERENCE SYMBOLS

[0038] 1. pre-chamber ignition system [0039] 1′ housing [0040] 2. cylinder head [0041] 3. ignition device [0042] 3′ ignition electrode [0043] 4. cavity [0044] 5 cover [0045] 6. combustion chamber [0046] 7. first aperture [0047] 8. cross-member [0048] 9. second aperture [0049] 10. central region [0050] 11. contact region