Lubricating compositions for preventing or reducing pre-ignition in an engine

Abstract

Disclosed is the use of a lubricating composition including at least one base oil and at least one polyalkylene glycol (PAG) produced by polymerisation or copolymerisation of alkylene oxides including between 3 and 8 carbon atoms, at least one of which being a butylene oxide, for preventing or reducing pre-ignition in an engine, preferably in a vehicle engine.

Description

[0001]The invention relates to the use of a lubricating composition to prevent or reduce pre-ignition in an engine. More particularly, the invention relates to the use of a lubricating composition comprising at least one base oil and at least one polyalkylene glycol (PAG) to prevent or reduce pre-ignition in an engine, preferably of a vehicle, particularly of a motor vehicle.[0002]The present invention also relates to a method for preventing or reducing pre-ignition in an engine, preferably of a vehicle, particularly of a motor vehicle using this lubricating composition.[0003]The present invention also relates to the use of a polyalkylene glycol (PAG) in a lubricating composition to prevent or reduce pre-ignition in an engine, preferably of a vehicle engine, particularly of a motor vehicle.TECHNOLOGICAL BACKGROUND[0004]Under ideal conditions, normal combustion in a spark-ignition engine occurs when a fuel mixture, in particular of fuel and air, is ignited in the combustion chamber i...

AI Technical Summary

Benefits of technology

The patent text describes the use of a lubricating composition that includes a base oil and a polyalkylene glycol (PAG) to prevent or reduce pre-ignition in an engine. The PAG is made by polymerizing or copolymerizing alkylene oxides with 3 to 8 carbon atoms, including one butylene oxide. This composition has good stability and can effectively prevent or reduce pre-ignition when used in an engine.

Problems solved by technology

However, in some cases, the air / fuel mixture may be prematurely ignited via a flame source prior to firing by the spark from the spark plug, leading to a phenomenon known as pre-ignition.

Yet, it is preferable to reduce and even eliminate pre-ignition since this generally translates as the presence of a strong rise in temperatures and pressures inside the combustion chamber, thereby having a significant negative impact on the efficiency and overall performance of an engine.

In addition, pre-ignition may cause significant damage to cylinders, pistons, plugs and valves in the engine and, in some cases, may even lead to engine failure even engine breakage.

Recently, Low Speed Pre-Ignition (LSPI) has been identified in particular by motor vehicle manufacturers, as being a potential problem for downsized engines.

LSPI generally occurs at low speeds and under heavy loads, and can cause serious damage to pistons and / or cylinders.

However, these solutions currently remain insufficient for a significant reduction in pre-ignition and are difficult to implement especially in countries in which a high basicity level is required for fuels.

In addition, problems of lubricant stability or compatibility with post-treatment systems are associated with these solutions.

Application WO2015023559 describes a method for reducing pre-ignition via the addition to a lubricant of an additive allowing delayed ignition, said additive being selected from among organic compounds comprising at least one aromatic core However, these light organic compounds could lead an excessive increase in the volatility of the lubricant.

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