Engine Intake Throttle Control via Differential Pressure Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing control methods for internal combustion engines require high-accuracy pressure sensors to manage the intake throttle valve opening degree accurately, leading to increased costs and reduced controllability with low-accuracy sensors, resulting in excessive differential pressure and pumping loss when trying to introduce EGR gas effectively.
Innovation Solution
The system uses an electronically controlled throttle and admission valve to control the differential pressure between the intake and exhaust passages, allowing for precise control of the admission valve opening degree based on the throttle opening degree, reducing the need for high-accuracy pressure sensors and minimizing pumping loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a pressure sensor having low accuracy is used, then cost is reduced, but the controllability of the intake throttle valve opening degree is reduced due to correspondingly low resolution
Solution Approach 1:
The patent introduces a differential pressure generating valve as an intermediary device between the intake throttle valve and the pressure sensor. This valve actively generates a differential pressure that amplifies the pressure signal, allowing a low-accuracy pressure sensor to effectively measure small pressure changes that would otherwise require a high-accuracy sensor. The intermediary device bridges the gap between limited sensor capability and the need for precise control.
2Reliability
If a target value of differential pressure between exhaust passage and intake passage is set to be larger than actually necessary, then EGR gas introduction is reliable, but intake throttle quantity increases and pumping loss increases
Solution Approach 1:
The patent employs dynamic control of the differential pressure generating valve opening degree based on real-time operating conditions. Instead of using a fixed, conservative target differential pressure value that would always ensure reliable EGR introduction but cause excessive pumping loss, the system dynamically adjusts the valve opening to generate just enough differential pressure for reliable EGR gas introduction under current engine conditions. This dynamic adjustment minimizes unnecessary throttling and reduces pumping loss while maintaining reliability.
3Ease of operation
If intake throttle valve opening degree is manipulated according to pressure detected by pressure sensor, then EGR gas can be introduced, but high-accuracy pressure sensor is needed and cost increases
Solution Approach 1:
The patent changes the pressure parameter by actively generating a differential pressure across the intake throttle valve using the differential pressure generating valve. This parameter transformation converts small, difficult-to-measure pressure drops into larger, more easily measurable differential pressure values. By changing the pressure parameter in this way, the system enables effective EGR gas introduction control using a low-accuracy, low-cost pressure sensor instead of requiring an expensive high-accuracy sensor.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An internal combustion engine includes an intake passage of the internal combustion engine, an exhaust passage of the internal combustion engine, and 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 an intake air quantity toward a downstream side of the connected part, and an intake throttle valve provided upstream of the connected part to the EGR passage in the intake passage. In a control device of the internal combustion engine, an opening degree of the intake throttle valve is determined on the basis of an opening degree of the throttle valve.