Cold starting control method of variable valve stroke direct injection engine

Abstract

The invention discloses a cold starting control method of a variable valve stroke direct injection engine, and a cold starting auxiliary system is arranged on an engine; according to the method, whenthe engine is in a cold starting state, in the manner of closing an inlet valve and exhaust valve and enabling a starter to drag a bent axle to rotate, a piston is enabled to act on the inlet compression of the inside of the cylinder and act on the cylinder wall by friction, the inlet temperatures of the cylinder wall, the piston rod, the cylinder cover and the side of the cylinder rise continuously, the purpose of preheating the engine is realized, and the starting efficiency of the engine is effectively improved. Through experiment verification, a spark ignition engine and a compression ignition engine can be started successfully under different cold stating environment temperatures, the starting efficiency is high, the fuel oil / air mixed gas quality is improved in the cold starting process, and exhaust gas emission of the direct injection engine is effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to a cold start control method of a variable valve lift in-cylinder direct injection engine. Background technique [0002] During the cold start of the direct injection engine, the temperature of the cylinder, intake air and fuel is very low, and the mixing time of fuel and air is very short, resulting in the inability to form a good combustible mixture with the air after the fuel is injected into the cylinder, resulting in difficulty in cold start of the engine. Even under low temperature and ultra-low temperature cold start state, the start cannot be completed. [0003] At present, the technical solutions to solve the cold start difficulties of direct injection engines mainly include intake air preheating and cylinder built-in heating plugs. The use of air intake preheating can improve the problem of difficult cold start of direct injection engines to a certain extent...

AI Technical Summary

Problems solved by technology

The use of air intake preheating can improve the problem of difficult cold start of direct injection engines to a certain extent, but due to the limited intake air volume, the preheating intensity is insufficient (especially for ignition direct injection engines), and the The cold start improvement effect of direct injection engine is not satisfactory

Using the built-in heating plug in the cylinder can well solve the problem of insufficient preheating, but the high temperature electric glow plug is very easy to ignite the fuel / air mixture in the early stage of the intake stroke or compression work stroke, resulting in abnormal engine operation

In addition, there are some schemes in the prior art that use external heaters to heat cooling water and lubricating oil to improve the cold start performance of direct injection engines. However, due to the complexity of the equipment and the low efficiency of energy utilization, the actual rarely used in

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