Control method for fuel supply in common rail type fuel injection system

Abstract

The invention discloses a fuel supply control method for a common rail type fuel injection system. The system comprises a high pressure pump, a container, a lubricating pipeline, a high pressure pipeline and a fuel metering unit, wherein a fuel lubricates the high pressure pump through the lubricating pipeline; the fuel metering unit controls the fuel supplied to the high pressure pump; and the high pressure pump pressurizes the fuel and supplies the pressurized fuel to the container through the high pressure pipeline. The method comprises the following steps: judging whether the pressure value at the oil inlet of the fuel metering unit is lower than a preset value or not; if the pressure value is lower than the preset value, judging that the pressure value of the lubricating pipeline is lower than a set value; and the step of judging whether the pressure value at the oil inlet of the fuel metering unit is lower than the preset value or not comprises: performing integral operation on adifference value between the actual pressure value of the container and a preset pressure value of the container; judging that the pressure value at the oil inlet of the fuel metering unit is lower than the preset value when the integral operation result is greater than a set threshold value; and when the pressure value of the lubricating pipeline is lower than the set value, adopting a degradingmeasure by the common rail type fuel injection system.

Description

technical field [0001] The invention relates to a common rail fuel injection system, in particular to a method for controlling fuel supply in the common rail fuel injection system. Background technique [0002] In a common rail fuel injection system applied to vehicles, a low-pressure pump supplies fuel from a fuel tank to a high-pressure pump through a low-pressure line, and a fuel metering unit adjusts the amount of fuel supplied to the high-pressure pump. The high pressure pump pressurizes the fuel and supplies it to the common rail. In order to make the common rail fuel injection system work normally, the high-pressure pump needs to be lubricated. The common lubrication methods include engine oil lubrication and fuel lubrication. The way of using fuel lubrication is simple and compact in structure, so it has gradually become the mainstream development direction. [0003] However, in some cases such as when the vehicle is at a high altitude, the fuel may not be sufficie...

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Problems solved by technology

[0003] However, in some cases, such as when the vehicle is at a high altitude, the fuel may not be sufficiently supplied to the lubrication line, so that the amount of lubricating oil may not reach the lubricating level

For another example, when the low-pressure pipeline of the vehicle fails, such as the oil inlet pipeline is too thin, the oil inlet pipeline is bent, the filter is clogged, etc., these conditions will also cause insufficient lubricating oil in the high-pressure pump, making the lubricating oil insufficient. to the required lubrication level

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