TRIBOLOGICAL SYSTEM, METHOD FOR PRODUCING A TRIBOLOGICAL SYSTEM AND INTERNAL COMBUSTION ENGINE WITH A TRIBOLOGICAL SYSTEM

Abstract

A tribological system for an internal combustion engine is disclosed. The tribological system includes a valve seat ring having a first contact surface and a valve having a second contact surface that can placed on the first contact surface for closing a valve opening and is arranged in a seat area of the valve. The valve in the seat area has a seat base composed of a high-nickel-content or a nickel-based material, and is coated with a nickel-based plating that comprises nickel as a main component, to form the second contact surface.

Claims

1. A tribological system for an internal combustion engine, comprising: a valve seat ring having a first contact surface, a valve having a second contact surface that can placed on the first contact surface for closing a valve opening and is arranged in a seat area of the valve, wherein the valve in the seat area has a seat base composed of a high-nickel-content or a nickel-based material, and is coated with a nickel-based plating that comprises nickel as a main component, to form the second contact surface.

2. The tribological system according to claim 1, wherein the nickel-based plating contains more than 30 percent by weight.

3. The tribological system according to claim 1, wherein the nickel-based plating comprises up to 3 percent by weight of carbon as an additional component.

4. The tribological system according to claim 1, wherein the nickel-based plating comprises up to 10 percent by weight of iron as an additional component.

5. The tribological system according to claim 1, wherein the nickel-based plating comprises up to 30 percent by weight of chromium as an additional component.

6. The tribological system according to claim 1, wherein the nickel-based plating comprises up to 9 percent by weight of molybdenum as an additional component.

7. The tribological system according to claim 1, wherein the nickel-based plating consists of the main component and at least one additional component.

8. The tribological system according to claim 1, wherein the seat base of the valve having the high nickel content or the nickel-based material comprises a material having a material number 2.4952.

9. The tribological system according to claim 1, wherein the valve is configured as a poppet valve having a valve disk and a valve stem protruding perpendicularly from the valve disk, wherein the valve disk comprises the seat base and the nickel-based plating with the second contact surface.

10. The tribological system according to claim 1, wherein the valve seat ring is composed of sintered material.

11. The tribological system according to claim 10, wherein the sintered material is a pressed and sintered powder mixture having the following composition: 5 to 45 percent by weight of one or more iron-based hard phases, 0 to 2 percent by weight of graphite particles, 0 to 2 percent by weight of manganese sulphide, 0 to 2 percent by weight of molybdenum disulphide, 0 to 2 percent by weight of monoiron phosphide powder, 0 to 7 percent by weight of copper powder and 0 to 4 percent by weight of cobalt powder, 0.1 to 1.0 percent by weight of a pressing additive, a high-speed steel having a composition of 14 to 18 percent by weight of chromium, 1.2 to 1.9 percent by weight of carbon, 0.1 to 0.9 percent by weight of silicon, 0.5 to 2.5 percent by weight of vanadium, 0.5 to 2.5 percent by weight of tungsten, 0.5 to 2.5 percent by weight of molybdenum and iron as a residue as well as manufacturing impurities of less than 1.5 percent by weight.

12. The tribological system according to claim 10, wherein the sintered materials includes one of: one or more iron-based hard phases have a composition of less than 0.2 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 8 to 12 percent by weight of chromium, 2.2 to 3 percent by weight of silicon, and or that one or more iron-based hard phases have a composition of less than 0.3 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 14 to 20 percent by weight of chromium, 2.9 to 4.2 percent by weight of silicon.

13. The tribological system according to claim 10 wherein the sintered material includes a cobalt-based hard phase having a fraction of 0.5 to 9.9 percent by weight.

14. The tribological system according to claim 10, wherein the sintered material is a pressed and sintered powder mixture having the following composition: one or more cobalt-based hard phases having a composition of less than 0.1 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 7 to 12 percent by weight of chromium, 2.0 to 4 percent by weight of silicon, 0 to 2 percent by weight of graphite particles, 0 to 2 percent by weight of manganese sulphide, 0 to 2 percent by weight of molybdenum disulphide, 0 to 2 percent by weight of monoiron phosphide powder, 0 to 7 percent by weight of copper and 0 to 4 percent by weight of cobalt powder, 0.1 to 1.0 percent by weight of a pressing additive a high-speed steel having a composition of 14 to 18 percent by weight of chromium, 1.2 to 1.9 percent by weight of carbon, 0.1 to 0.9 percent by weight of silicon, 0.5 to 2.5 percent by weight of vanadium, 0.5 to 2.5 percent by weight of tungsten, 0.5 to 2.5 percent by weight of molybdenum, and cobalt as a residue as well as manufacturing impurities of less than 1.5 percent by weight.

15. The tribological system according to claim 14, further comprising one or more cobalt-based hard phases having a composition of less than 0.2 percent by weight of carbon, 18 to 25 percent by weight of molybdenum, 12 to 20 percent by weight of chromium, 1.0 to 3 percent by weight of silicon.

16. A method for producing a tribological system, comprising: providing a valve seat ring having a first contact surface; providing a valve having a second contact surface arranged in a seat area of the valve that can be placed on the first contact surface for closing a valve opening; forming a seat base of the valve with a high nickel content a nickel-based material in the seat area to provide the second contact surface and coating the seat base with a nickel-based plating.

17. An internal combustion engine, comprising: a tribological system including: a valve seat ring having a first contact surface, a valve having a second contact surface that can placed on the first contact surface for closing a valve opening and is arranged in a seat area of the valve, wherein the valve in the seat area has a seat base composed of a high-nickel-content or a nickel-based material, and is coated with a nickel-based plating that comprises nickel as a main component, to form the second contact surface, and a charge exchange channel that can be closed or released fluidically via the tribological system so that the tribological system together with the charge exchange channel forms a charge exchange member.

18. The internal combustion engine according to claim 17, wherein the nickel-based plating contains at least 50 percent by weight of nickel.

19. The internal combustion engine according to claim 18, wherein the nickel-based plating comprises up to 3 percent by weight of carbon as an additional component.

20. The internal combustion engine according to claim 18, wherein the nickel-based plating comprises up to 10 percent by weight of iron as an additional component.

Description

BREIF DESCRIPTION OF THE DRAWINGS

[0029] The Figure illustrates in axial section a tribological system according to an example.

DETAILED DESCRIPTION

[0030] The only Figure shows schematically in axial section an example of a tribological system 1 according to the invention, which can preferably be used for a charge exchange member 2 of an internal combustion engine 3 according to the invention which is also shown as an example. The tribological system 1 comprises a valve seat ring 5 on which a first contact surface 4 is provided. In addition, the tribological system 1 comprises a valve 7 on which a second contact surface 6 is provided. The second contact surface 6 of the valve 7 can be placed on the first contact surface 4 of the valve seat ring to close a valve opening 8. The second contact surface 6 is arranged in a seat area 9 of the valve 7. In its seat area 9 the valve 7 has a seat base 10 having a high nickel content or comprising a nickel-based material. The seat base 10 of the valve 7 is plated or coated with a nickel-based plating 11 so that the plating 11 forms the second contact surface 6 of the valve 7.

[0031] The nickel-based plating 11 has nickel as the main component with more than 30 percent by weight, preferably at least 50 percent by weight, most preferably at least 52 percent by weight. The nickel-based plating 11 has a fraction of carbon of up to 3 percent by weight as additional component. In addition, the nickel-based plating 11 comprises a fraction of iron of up to 10 percent by weight as additional component. Furthermore, the nickel-based plating 11 comprises a fraction of chromium of up to 30 percent by weight. Furthermore, the nickel-based plating 11 has a fraction of molybdenum of up to 9 percent by weight as additional component. The seat base 10 of the valve 7 having a high nickel content or comprising a nickel-based material comprises a material having the material No. 2.4952 or consists of such a material.

[0032] Expediently the plating 11 can consist of the main component nickel and of additional components, in the example, carbon, iron, chromium, molybdenum. In all the variants described in it feasible that the plating 11 has impurities due to the manufacturing process having a weight fraction of up to 0.2 percent by weight. In this case, the impurities are formed by substances which differ from the main component nickel and from the previously explained additional components.

[0033] The Figure furthermore reveals that the valve 7 is configured as a poppet valve 12. The valve 7 configured as poppet valve 12 comprises a valve disk 13 as well as a valve stem 14 which protrudes substantially perpendicularly from the valve disk 13. In this case, the valve disk 13 comprises the seat base 10 having a high nickel content or comprising a nickel-based material and the plating 11 with the second contact surface 6.

[0034] According to the Figure, the valve seat ring 5 is made of a sintered material 15. The sintered material 15 of the valve seat ring 5 can be obtained by pressing and sintering a powder mixture having a composition explained hereinafter. The powder mixture comprises 5 to 45 percent by weight of one or more iron-based hard phases. In addition, the powder mixture comprises 0 to 2 percent by weight of graphite particles, 0 to 2 percent by weight of manganese sulphide, 0 to 2 percent by weight of molybdenum sulphide as well as 0 to 2 percent by weight of mono-iron phosphide powder. Furthermore, the powder mixture comprises 0 to 7 percent by weight of copper powder and 0 to 3 percent by weight of cobalt powder. In addition, the powder mixture comprises 0.1 to 1.0 percent by weight of a pressing additive. The powder mixture additionally has a fraction of high-speed steel having a composition of 14 to 18 percent by weight of chromium, 1.2 to 1.9 percent by weight of carbon, 0.1 to 0.9 percent by weight of silicon, 0.5 to 2.5 percent by weight of vanadium, 0.2 to 2.5 percent by weight of tungsten as well as 0.5 to 2.5 percent by weight of molybdenum. In addition, the powder mixture comprises a residue of iron as well as impurities due to the manufacturing process. Such impurities due to the manufacturing process can comprise copper, cobalt, calcium and/or manganese, wherein the impurities each make up a fraction of less than 1.5 percent by weight of the residue of the powder mixture. One or more of the iron-based hard phases has or have a composition with less than 0.2 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 8 to 12 percent by weight of chromium as well as 2.2 to 3 percent by weight of silicon. Alternatively to the previously explained composition, one or more of the iron-based hard phases has or have a composition with less than 0.3 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 14 to 20 percent by weight of chromium as well as 2.9 to 4.2 percent by weight of silicon. In the example shown in the Figure, a cobalt-based hard phase having a fraction of the powder mixture of 0.5 to 9.9 percent by weight is additionally present in the powder mixture.

[0035] The sintered material 15 of the valve seat ring 5 can alternatively be obtained by pressing and sintering a powder mixture having a composition indicated hereinafter. In this case, the powder mixture comprises one or more cobalt-based hard phases having a composition with less than 0.1 percent by weight of carbon, 26 to 32 percent by weight of molybdenum, 7 to 12 percent by weight of chromium as well as 2.0 to 4 percent by weight of silicon. In addition, the powder mixture comprises 0 to 2 percent by weight of graphite particles as well as 0 to 2 percent by weight of manganese sulphide, 0 to 2 percent by weight of molybdenum sulphide and 0 to 2 percent by weight of mono-iron phosphide powder. Furthermore, the powder mixture comprises 0 to 7 percent by weight of copper powder and 0 to 4 percent by weight of cobalt powder. Furthermore, the powder mixture comprises 0.1 to 1.0 percent by weight of a pressing additive as well as high-speed steel having a composition of 14 to 18 percent by weight of chromium, 1.2 to 1.9 percent by weight of carbon, 0.1 to 0.9 percent by weight of silicon, 0.5 to 2.5 percent by weight of vanadium, 0.5 to 2.5 of tungsten as well as 0.5 to 2.5 percent by weight of molybdenum. The powder mixture additionally comprises a residue which is formed by cobalt as well as impurities due to the manufacturing process. Such impurities can be nickel, copper, calcium and/or manganese with fractions in the residue of less than 1.5 percent by weight. In this case, the powder mixture comprises one or more cobalt-based hard phases with a composition of less than 0.2 percent by weight of carbon, 18 to 25 percent by weight of molybdenum, 12 to 20 percent by weight of chromium as well as 1.0 to 3 percent by weight of silicon.

[0036] The tribological system 1 shown in the Figure is produced by means of a method according to the invention. According to this method, a seat base 10 of a valve 7 having a high nickel content or comprising a nickel-based material in a seat area 9 of the valve 7 forming a second contact surface 6 of the valve 7, which can be placed on a first contact surface 4 of a valve seat ring 5 of the tribological system 1 is plated or coated with a nickel-based plating 11.

[0037] Furthermore, the Figure also shows roughly schematically an internal combustion engine 3, in particular for a motor vehicle. The internal combustion engine 3 comprises a tribological system 1 which is produced in particular by means of the previously explained method according to the invention. In addition, the internal combustion engine 3 comprises a charge exchange channel 16. The charge exchange channel 16 of the internal combustion engine 3 can be closed or released fluidically by means of the tribological system 1 so that the tribological system 1 together with the charge exchange channel 16 form a charge exchange member 2 of the internal combustion engine 3.