Engine fuel system and engine

Abstract

The invention belongs to the technical field of engines and particularly relates to an engine fuel system and an engine. The engine fuel system comprises a variable flow electric fuel delivery pump, afuel filter and a high-pressure pump, wherein the electric fuel delivery pump is used for pumping out fuel in an oil tank and delivering the fuel into the high-pressure pump through a low-pressure pipe; the fuel filter is arranged on a fuel pipe between the electric fuel delivery pump and the high-pressure pump and used for filtering the fuel pumped out from the electric fuel delivery pump; and the high-pressure pump is used for supercharging the fuel and delivering the fuel to a common rail pipe through a high-pressure oil pipe. Through the engine fuel system and the engine, low-pressure system configuration of the fuel system can be optimized effectively, and the number of parts is reduced; moreover, the reliability of the system is improved, the flow of the electric fuel delivery pumpis made to be irrelevant to the rotating speed of the engine, and the problems that fuel supply is slow in case of low speed and is surplus in case of high speed are solved.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to an engine fuel system and an engine. Background technique [0002] In existing engines, especially fuel (eg, diesel) engines, a high-pressure fuel pump is usually used to convert low-pressure fuel (eg, low-pressure diesel) from a fuel tank into high-pressure fuel. For example, figure 1 It is a hydraulic schematic diagram of an engine fuel system in the prior art. When the engine is started, the fuel stored in the first fuel tank 10' is pumped by the mechanical first fuel pump 20' through the fuel filter After being filtered by the filter, it is sent to the first oil quantity metering valve 30' through the low-pressure oil pipe. Subsequently, the fuel is delivered to the first high-pressure pump 40' after being metered by the first fuel quantity metering valve 30', and after being pressurized by the first high-pressure pump 40', it enters the common rail pipe through...

AI Technical Summary

Problems solved by technology

[0003] Structurally, the first oil delivery pump 20' is integrated on the high-pressure oil pump, and the first electric pump 50' for exhaust is added in the front section. The structure and parts are relatively complicated and the failure rate is high. The oil supply characteristics of the oil pump are related to the engine speed, which has the problem of slow oil supply at low speed and excess oil supply at high speed, which does not reflect the characteristics matching the engine, resulting in waste of energy

In terms of function, the back pressure of the first fuel delivery pump 20' is not monitored, only a safety valve is provided, and it is not considered from the perspective of practical application. The maintenance of the filter element is replaced by the number of kilometers or hours, resulting in the utilization rate of the filter element. Too low, waste of energy

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