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Method and equipment for detecting misfire of diesel engine

A diesel engine and equipment technology, applied in the direction of internal combustion engine testing, etc., can solve problems such as inaccurate judgment, achieve the effects of improving judgment accuracy, resisting signal interference, and improving accuracy

Active Publication Date: 2013-03-20
WEICHAI POWER CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Can't tell exactly which cylinder is misfiring.

Method used

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  • Method and equipment for detecting misfire of diesel engine
  • Method and equipment for detecting misfire of diesel engine
  • Method and equipment for detecting misfire of diesel engine

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Embodiment Construction

[0042] In order to enable those skilled in the art to better understand and implement the technical solution provided by the present invention, several technical terms in this field are introduced below.

[0043] Misfire: A phenomenon in which the fuel injector does not inject fuel or the fuel injected basically does not burn.

[0044] Acceleration between cylinders: calculate the angular acceleration between cylinders = (the average angular velocity of the current cylinder - the average angular velocity of the previous cylinder) / the sum of the time of the corresponding teeth of the two cylinders;

[0045] For example: for a crankshaft with 60 teeth in one circle, spray 3 times; then, the average angular velocity: extract the instantaneous rotational speed corresponding to 20 teeth of the current cylinder, multiply it by 2π and divide by 60 to get the instantaneous angular velocity corresponding to 20 teeth, and then take the average value;

[0046] Note: For the first cylin...

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PUM

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Abstract

The invention provides a method and equipment for judging misfire of a diesel engine. The method comprises the steps that instant rotating speeds n of crankshaft teeth corresponding to cylinders are collected in a working cycle; average angular speeds omega of the cylinders are calculated due to the instant rotating speeds n of the crankshaft teeth corresponding to the cylinders; angular acceleration alpha among the cylinders is calculated with the average angular speeds omega of the cylinders according to a formula as described in the specification; omega1 is the average angular speed of the current cylinder; omega2 is the average angular speed of the previous cylinder; delta t is a time sum corresponding to the crankshaft teeth of the two cylinders; and whether the angular acceleration alpha among the cylinders is smaller than a preset misfire threshold value is judged, if so, the current cylinder has the misfire, and otherwise, no cylinder has the misfire. As the angular acceleration among the cylinders is obtained by collecting the instant rotating speeds of the crankshaft teeth in every working cycle, the accuracy of judging the misfire is improved. In addition, as the angular acceleration among the cylinders is obtained according to the difference between average angular speeds of the current cylinder and the previous cylinder, the angular acceleration among the cylinders can resist signal interference of the individual cylinders effectively. The accuracy of judging the cylinders have the misfire is improved.

Description

technical field [0001] The invention relates to the technical field of diesel engine control, in particular to a method and equipment for detecting diesel engine misfire. Background technique [0002] In the prior art, for an electronically controlled engine, the engine may misfire due to reasons such as an open circuit of a driving pin, or blockage of a fuel injector, or damage to a solenoid valve. When the engine misfires, the working vibration of the engine is large, the power is limited, and the impact on the crankshaft is relatively large. If it is possible to quickly determine which cylinder is misfired, it will be of great significance to repair or replace it in time. [0003] Currently, determining which cylinder is misfired is done by detecting the instantaneous rotational speed for peak extraction or performing integral processing for each cycle to compare the difference of each cylinder. [0004] Such as figure 1 As shown in the prior art, it is a waveform diagr...

Claims

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Application Information

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IPC IPC(8): G01M15/11
Inventor 刘兴义史家涛李云霞穆大芸李栋
Owner WEICHAI POWER CO LTD
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