EGR Valve Control Using Intake Temperature Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing EGR control devices require multiple sensors around the EGR passage to calculate the target EGR valve opening degree, leading to a complex configuration and increased costs.
Innovation Solution
An EGR control device that uses a drive unit to vary the EGR valve opening degree, a basic opening degree deriving unit to determine the basic EGR valve opening based on engine conditions, a measurement unit to measure downstream intake passage temperature, and a correction opening degree deriving unit to estimate the correction amount using stored temperature difference information, allowing for accurate EGR gas control without the need for EGR pressure and temperature sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors (EGR pressure sensor, EGR temperature sensor) are disposed in the EGR passage to calculate target EGR valve opening degree, then measurement precision of EGR gas parameters is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the measurement function from the EGR passage to the intake passage downstream, where a single temperature sensor suffices. By measuring intake air temperature downstream and using it to infer EGR gas characteristics, the system eliminates the need for multiple sensors in the EGR passage, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The single temperature sensor in the intake passage serves multiple functions: it measures intake air temperature, indirectly characterizes EGR gas temperature, and enables calculation of target EGR valve opening degree. This multi-functional approach replaces the need for separate EGR temperature sensors, reducing device complexity.
2Measurement precision
If multiple sensors (EGR pressure sensor, EGR temperature sensor) are disposed in the EGR passage to calculate target EGR valve opening degree, then measurement precision of EGR gas parameters is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts the measurement function from the EGR passage to the intake passage downstream, where a single temperature sensor suffices. By measuring intake air temperature downstream and using it to infer EGR gas characteristics, the system eliminates the need for multiple sensors in the EGR passage, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The patent employs a single, simpler temperature sensor in the intake passage instead of multiple expensive sensors in the EGR passage. This substitution with a more economical sensor achieves the same measurement objectives at lower manufacturing cost.
3Ease of operation
If EGR valve opening degree is controlled based on basic opening degree without correction, then ease of operation is improved, but manufacturing precision of EGR gas amount control deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the measured intake air temperature downstream is used to calculate a correction amount that adjusts the basic EGR valve opening degree. This feedback loop ensures precise control of EGR gas amount by compensating for deviations from target values, thereby improving manufacturing precision while maintaining ease of operation through automated correction.
Solution Approach 2:
The patent performs preliminary calculation of correction amounts based on pre-stored relationships between intake air temperature and EGR valve opening degree corrections. This preliminary preparation of correction data enables rapid, precise adjustment without complex real-time calculations, maintaining ease of operation while achieving high manufacturing precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the configuration and reduces costs while accurately controlling the amount of EGR gas introduced into the intake passage by estimating the correction amount based on intake air temperature, ensuring precise EGR gas control.
Implementation Method 1
a measurement unit configured to measure a temperature in the downstream side of a position where an EGR gas is recirculated in an intake passage
Implementation Method 2
a correction opening degree deriving unit configured to derive a correction opening degree of the EGR valve with reference to the information, based on the temperature difference between the temperature when the EGR valve is set to the reference opening degree and the temperature when the EGR valve is set to the basic EGR valve opening degree
Data Source
AI summary
An EGR control device includes: a drive unit, a basic opening degree deriving unit, a measurement unit, a memory unit, a correction opening degree deriving unit and a control unit. The drive unit varies an opening degree of an EGR valve. The basic opening degree deriving unit derives a basic EGR valve opening degree based on an operating condition of an engine. The measurement unit measures a temperature in the downstream side of a position of where EGR gas is recirculated in an intake passage. In the memory unit, information acquired in advance is stored. The information indicates a relationship between the opening degree and a temperature difference. The correction opening degree deriving unit derives a correction opening degree with reference to the information. The control unit controls the drive unit such that the opening degree of the EGR valve becomes a target EGR valve opening degree by correcting the basic EGR valve opening degree with the correction opening degree.