RU165036U1 - Piston for internal combustion engine with catalytically active thermal barrier ceramic coating on the surface of the bottom, piston skirt and piston ring grooves - Google Patents

Abstract

A piston of an internal combustion engine with a catalytically active thermal barrier ceramic coating containing alumina, cerium oxide, characterized in that the coating is additionally applied in the area of the piston rings.

Description

A piston of an internal combustion engine with a catalytically active thermal barrier ceramic coating on the surface of the bottom, piston skirt and piston ring grooves.

The utility model relates to engine building, and in particular to pistons of an internal combustion engine (ICE) with a catalytically active thermal barrier ceramic coating.

Known patent (US4245611 (A) - 1981-01-20 F02B23 / 06), ceramic insulation of the piston in the engine. It proposes to insulate the central part of the piston bottom with a ceramic plate, which is made in the form of an inverted cone. In this case, the excess voltage acting on the ceramic liner is absorbed by the layer of fibrous metal located between the liner and the piston.

Also known patent application (JP47-168729, F 02F 3/10, 1982) a method of manufacturing a piston with ceramic insulation. A layer of a composite of inorganic metal fibers and a light alloy is glued on the piston bottom. Then, a layer of heat-resistant alloy is applied to the composite layer, and a layer of ceramic material is applied to it.

There is a patent (US4735128 (A) - 1988-04-05 F 02F 3/06). It offers thermal insulation of the piston bottom, carried out by mechanical connection between the ceramic liner and the piston. The mechanical connection is carried out by filling the pores present in the ceramic part with the piston material that occurs during molding with prepress.

The methods of thermal insulation proposed by the authors using an intermediate layer between metal and ceramics, as well as mechanical bonding, are carried out by filling metal into the pores of the ceramic material. In the above examples, differences in the linear expansion coefficients of the two materials, aluminum and ceramic, lead to the inevitable destruction of the ceramic lining upon heating and cooling. In addition, these methods are quite laborious.

A patent is known for a utility model (RU 56483 F02B77 / 02.09.09.2006) the piston of an internal combustion engine. Made of a light alloy containing aluminum, it is made of an alloy with a working temperature of at least 300 ° C and is provided on the outer surface with a heat-protective, wear-resistant coating made in an electrolyte in the microplasma oxidation mode. The coating is made of corundum.

The disadvantage is that the piston coating is made of alumina without the addition of cerium oxide, in contrast to the inventive piston, in addition to alumina, cerium oxide is added to the coating composition, which is an effective catalyst accelerating the process and completeness of fuel combustion, which is necessary during the operation of ICE .

The closest analogue is the patent (RU 155143 F02B77 / 02) for the piston of an internal combustion engine with a catalytically active thermal barrier ceramic coating. A catalytically active ceramic thermal barrier coating based on alumina and cerium oxide is formed on the internal combustion engine piston by the method of microarc (plasma electrolytic) oxidation.

Its disadvantages include the fact that a catalytically active ceramic thermal barrier coating is applied only to the bottom and to the piston skirt, in contrast to the inventive piston, which is additionally coated with a ceramic thermal barrier coating in the area of the piston ring grooves.

Thanks to the coating applied in the area of the grooves of the piston rings, a multiple increase in the resource of the groove and the ring, the correct operation of the piston ring together with the cylinder liner is provided, preventing the ring from caving in the worn groove and cutting the surface of the cylinder with a worn ring. As a result, the resource of the cylinder-piston group can be increased several times.

The oxide layers obtained by the microarc oxidation method are characterized by high adhesion, resistance to thermal shock, and thermal cycling. Such a coating is also characterized by unique high hardness (up to 2000-2500 kg / mm2) and wear resistance when paired with similar ceramics, steel or cast iron.

Cerium oxide, as well as its binary and ternary oxides (including with aluminum) are effective catalysts for the conversion of hydrocarbons and carbon monoxide (CO) at sufficiently low temperatures (about 500 ° C, which corresponds to the conditions of the chamber of an internal combustion engine), accelerating the process and completeness of fuel combustion.

The objective of the authors is to increase the reliability and efficiency of the internal combustion engine pistons, increase the internal combustion engine's efficiency (Efficiency), and reduce the level of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbon emissions into the environment.

The problem is solved thanks to the formation of the internal combustion engine on the piston, in particular on the surface of the bottom, piston skirt and piston ring grooves,

catalytically active ceramic thermal barrier coating, based on aluminum oxide and cerium oxide, by the method of microarc (plasma electrolytic) oxidation.

The essence of the utility model is the possibility of a multiple increase in the resource of the groove and ring, the correct operation of the piston ring together with the cylinder liner, and the increase in the completeness of fuel combustion, which leads to a decrease in the level of emissions of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons into the environment and how the consequence is an increase in the efficiency of the internal combustion engine due to the formation of the internal combustion engine on the piston

catalytically active ceramic thermal barrier coating, based on aluminum oxide and cerium oxide, by the method of microarc (plasma electrolytic) oxidation.

The figure shows the piston of the internal combustion engine 1 with a catalytically active thermal barrier ceramic coating 2.

Utility Model Implementation:

On the surface of the bottom, piston skirt and piston ring grooves of the engine 1, by the method of microarc (plasma electrolytic) oxidation, a two-layer catalytically active thermobarrier ceramic coating 2 is formed, with a thickness of 15-150 microns. The first (inner) coating layer, 5-100 microns thick., Consists mainly of aluminum (not less than 90 mol.%) And is in direct contact with the metal from which the piston and the head of the ICE chamber sphere are made. The first layer has high hardness and wear resistance. The second (outer) porous layer, 10-100 microns thick., Consists of aluminum oxide, silicon oxide and cerium oxide in a mole fraction of 1 to 50%. The second layer has high adhesive strength, resistance to thermal shock and thermal cycling, and also has a thermal barrier and catalytic effect. Additionally, the coating may contain oxides of copper and magnesium.

The technical effect of using the piston of an internal combustion engine with a catalytically active thermal barrier ceramic coating is:

- increase the temperature in the combustion chamber;

- increase the completeness of fuel combustion;

- reduction of emissions of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons in the environment;

- reduction of thermal load on the cooling system and other engine parts;

- increase the efficiency of the internal combustion engine.

- provides a multiple increase in the resource of the grooves and rings, the correct operation of the piston ring together with the cylinder liner

Thus, the task facing the authors to increase the reliability and efficiency of the internal combustion engine pistons, increase the internal combustion engine's efficiency coefficient (Efficiency), internal combustion engine resource, and reduce the level of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbon emissions into the environment, has been achieved.

Claims (1)

A piston of an internal combustion engine with a catalytically active thermal barrier ceramic coating containing alumina, cerium oxide, characterized in that the coating is additionally applied in the area of the piston rings.

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