Diesel injector capable of successively injecting oil

Abstract

The invention aims to provide a diesel injector capable of successively injecting oil. The diesel injector comprises an outer shell and a needle valve body. The needle valve body is located in the outer shell. The outer shell is provided with an oil inlet groove and a needle valve cavity. The oil inlet groove is communicated with the needle valve cavity. The needle valve body comprises a sealing piston and a needle valve conical surface, wherein the sealing piston is arranged on the end portion of the needle valve body, and the needle valve conical surface is located above the sealing piston. The inner wall of the outer shell is provided with a needle valve sealing surface which is located below the needle valve cavity. An oil injection cavity is formed between the sealing piston and the bottom end of the inner wall of the outer shell. The needle valve cavity is communicated with the oil injection cavity through passages. The upper ends of the passages are located in the needle valve sealing surface. When the needle valve body drops in place, the needle valve conical surface is matched with the needle valve sealing surface to enable the passages to be disconnected with the needle valve cavity. A first layer of spray orifices and a second layer of spray orifices are formed in the bottom end of the outer shell respectively. The first layer of spray orifices is located below the second layer of spray orifices. Through the diesel injector capable of successively injecting the oil, the fuel oil atomization performance at low load, the fuel oil wall-wetting phenomenon at high load and fuel oil distribution uniformity in the air are improved, so efficiency is improved, and soot emission and HC emission are reduced.

Description

technical field [0001] The invention relates to a diesel engine, specifically a fuel injector for a diesel engine. Background technique [0002] The fuel injectors used in existing diesel engines can basically guarantee better atomization at medium and high loads, because the fuel injection pressure is higher at medium and high loads, and the designed nozzle size of the fuel injector can ensure better atomization effect. But at low load, if the original nozzle hole is still used, due to the small amount of fuel injection, if the high-pressure common rail fuel injection system is not used, the fuel injection pressure is also low at this time, and a better atomization effect cannot be guaranteed; If a high-pressure common rail fuel injection system is adopted, the fuel atomization effect can be further improved due to the less fuel injection. For diesel engines, how to improve fuel atomization under low operating conditions has always been a difficult problem for everyone. A...

AI Technical Summary

Problems solved by technology

But the cost is high, and the installation position of the fuel injector cannot be guaranteed, which will also reduce the strength of the cylinder head

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