Engine Intake Throttle Valve Control via Air Quantity
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Solution Overview
Problem
Existing control methods for internal combustion engines require high-accuracy pressure sensors to manage intake throttle valve opening, leading to increased costs and reduced controllability with low-accuracy sensors, resulting in excessive pumping loss and output reduction when trying to introduce EGR gas.
Innovation Solution
A control device that determines the intake throttle valve opening degree based on intake air quantity, using a controller to manage the admission valve and EGR valve to introduce EGR gas while minimizing pumping loss by setting a suitable differential pressure between the intake and exhaust passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure sensor with high accuracy is used to control intake throttle valve opening degree, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes the pressure sensor from the control system entirely. Instead of measuring pressure to control the intake throttle valve, the system uses a different control approach that determines valve opening based on other parameters, thereby eliminating the need for expensive high-accuracy pressure sensors while maintaining control functionality
Solution Approach 2:
The patent replaces the expensive high-accuracy pressure sensor with a control method that can function with lower measurement requirements or alternative sensing approaches, effectively substituting a costly component with a more economical solution that achieves the same control objective
2Device complexity
If a pressure sensor with low accuracy is used to control intake throttle valve opening degree, then device complexity is reduced, but measurement precision deteriorates, leading to reduced controllability
Solution Approach 1:
The patent eliminates the pressure sensor from the control loop, thereby removing the constraint of measurement precision limitations. By using an alternative control strategy that does not depend on pressure sensor feedback, the system achieves good controllability without relying on accurate pressure measurements
3Reliability
If a large differential pressure is set between exhaust passage and intake passage to reliably introduce EGR gas, then reliability of EGR introduction is improved, but pumping loss increases, causing output reduction
Solution Approach 1:
The patent changes the control parameter from pressure differential to a different set of parameters (such as valve timing, valve opening duration, or flow rate parameters) that allow reliable EGR introduction without requiring excessive differential pressure, thereby reducing pumping loss while maintaining EGR reliability
Solution Approach 2:
The patent employs dynamic control of the intake throttle valve where the valve opening is adjusted based on real-time operating conditions rather than maintaining a fixed large differential pressure. This dynamic approach ensures sufficient EGR flow under varying conditions while minimizing energy loss during normal operation
Data Source
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AI summary
An internal combustion engine includes an intake passage of the internal combustion engine, an exhaust passage of the internal combustion engine, an EGR passage connecting the intake passage and the exhaust passage. The internal combustion engine further includes a throttle valve provided downstream of a connected part to the EGR passage in the intake passage, and configured to control a quantity of intake air flowing into the internal combustion engine, and an intake throttle valve provided upstream of the connected part to the EGR passage in the intake passage. A control device controls the internal combustion engine, in which device an opening degree of the intake throttle valve is determined on the basis of an intake air quantity.