Evaporated Fuel Processing Device with Ejector for Supercharged Engine Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing evaporated fuel processing devices for vehicles with superchargers lack control over the supply amount of evaporated fuel when the supercharger is running, affecting the air-fuel ratio and air supply, especially when the downstream pressure is close to atmospheric pressure.
Innovation Solution
An evaporated fuel processing device with a canister, purge passage, purge control valve, and ejector that branches into first and second passages, allowing precise control of evaporated fuel supply to the intake pipe based on pressure measurements, enabling accurate flow rate determination and adjustment through tables and correction coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If evaporated fuel is supplied to the intake pipe through the second passage when the supercharger is running, then the evaporated fuel can be supplied during positive pressure conditions, but the supply amount of evaporated fuel cannot be controlled
Solution Approach 1:
The patent controls the supply amount of evaporated fuel by changing the opening degree of the purge control valve, which adjusts the flow characteristics and pressure differential across the valve. This parameter change enables precise control of fuel supply rate while maintaining the ability to operate under positive pressure conditions through the second passage.
2Device complexity
If a purge control valve is installed only on the first passage, then the structure is simpler, but the supply amount of evaporated fuel cannot be controlled when supplying through the second passage
Solution Approach 1:
The purge control valve installed on the common portion of the purge passage serves both passages (first and second passages) for controlling evaporated fuel supply. By positioning the valve upstream of the branch point, a single valve实现对 both supply routes control capability, reducing device complexity while maintaining precise control functionality.
3Productivity
If the downstream pressure of the supercharger is close to atmospheric pressure, then the air supply amount by supercharger is reduced, but the air-fuel ratio control becomes more critical and difficult
Solution Approach 1:
The system uses feedback from pressure sensors to detect the downstream pressure of the supercharger and adjusts the purge control valve opening degree accordingly. When downstream pressure is close to atmospheric pressure, the control unit increases control precision of the purge valve to maintain accurate air-fuel ratio, compensating for reduced supercharger effectiveness.
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
Enables precise control of the evaporated fuel supply to the internal combustion engine, improving the air-fuel ratio and accommodating varying pressure conditions, ensuring accurate fuel delivery even when the supercharger transitions or operates near atmospheric pressure.
Implementation Method 1
An ejector is connected to the intake pipe in parallel to the supercharger at positions of the intake pipe on upstream and downstream sides of the supercharger. A negative pressure generated by the ejector is used to supply the evaporated fuel to the intake pipe
Implementation Method 2
a canister configured to adsorb the fuel evaporated in the fuel tank
Data Source
AI summary
An intake pipe of an evaporated fuel processing device is provided with a throttle valve downstream of a supercharger, and an ejector in parallel to the supercharger. A purge passage is branched into first and second branch passages, which connect to the intake pipe at a position downstream of the throttle valve and to a suction port of the ejector, respectively. In the ejector, its intake port is connected to the intake pipe at a position between the supercharger and the throttle valve, and its exhaust port is connected to the intake pipe at a position upstream of the supercharger. A flow rate of purge gas in the second branch passage is obtained based on at least two of a first pressure downstream of the throttle valve, a second pressure between the supercharger and the throttle valve, and a third pressure upstream of the supercharger.