Active Crankcase Ventilation Flow Control via Solenoid Valve
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Solution Overview
Problem
Existing engine systems face challenges in coordinating throttle bypass flows, particularly during idle conditions, where standard PCV valve configurations restrict crankcase ventilation flow, leading to inadequate ventilation and oil separation efficiency, especially in cold weather or during gasoline direct injection engines with fuel dilution.
Innovation Solution
An electrically controlled crankcase ventilation valve is introduced to selectively enable crankcase ventilation flow based on desired engine air and fuel flow rates, current contributions from a brake booster, and fuel vapor purge system, using a solenoid valve and variable pressure control to optimize flow rates and prevent excessive air or fuel flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a standard PCV valve with small orifice is used to limit crankcase ventilation flow during idle conditions, then engine air consumption is reduced and idle air flow rate is limited, but crankcase ventilation adequacy deteriorates and oil separation efficiency decreases
Solution Approach 1:
The patent applies dynamics by transitioning from a static PCV valve with fixed orifice sizes to a dynamic system with an electrically controllable crankcase ventilation valve. This valve can actively adjust its opening degree based on real-time engine operating conditions (idle, warm-up, cold weather), enabling the system to optimize crankcase ventilation flow dynamically rather than being constrained by fixed flow limitations.
Solution Approach 2:
The patent implements parameter changes by modifying the crankcase ventilation valve's opening degree as a controllable parameter. The electrically controllable valve responds to signals from the engine control system, adjusting the valve opening parameter to achieve desired ventilation flow rates under different operating conditions, thereby resolving the contradiction between limiting air consumption and ensuring adequate ventilation.
2Ease of operation
If a standard PCV valve with small orifice is used to limit crankcase ventilation flow, then idle air flow rate is controlled, but oil separation efficiency deteriorates due to low velocity through the oil separator
Solution Approach 1:
The system applies dynamics by using an electrically controllable valve that can adjust the crankcase ventilation flow rate in real-time. During idle conditions, the valve can be positioned to provide optimal flow that maintains both idle air flow control and sufficient velocity through the oil separator for effective separation, unlike the fixed small orifice design.
Solution Approach 2:
The patent changes the flow rate parameter dynamically through electrical control of the crankcase ventilation valve. By adjusting the valve opening degree parameter, the system can optimize the balance between idle air flow control and oil separation efficiency, ensuring adequate flow velocity through the oil separator while maintaining proper idle characteristics.
3Quantity of substance
If crankcase ventilation flow is limited through a small orifice during idle conditions, then engine air flow budget is preserved for other flows, but fuel dilution increases during cold weather or short engine use
Solution Approach 1:
The patent applies dynamics by implementing an electrically controllable crankcase ventilation valve that can adjust flow rates based on engine operating conditions. During cold weather or short engine use, the system can increase ventilation flow to prevent fuel dilution, while during normal idle conditions, it can limit flow to preserve air flow budget, thereby resolving the contradiction through dynamic adaptation.
Solution Approach 2:
The system implements parameter changes by varying the crankcase ventilation flow rate parameter in response to different operating conditions. The electrically controllable valve adjusts this parameter to increase flow during cold weather/short use (reducing fuel dilution) and decrease flow during normal idle (preserving air flow budget), thus resolving the contradiction.
4Device complexity
If a standard PCV valve configuration with fixed orifices is used, then device complexity is minimized, but adaptability to different operating conditions deteriorates
Solution Approach 1:
The patent applies dynamics by replacing the static fixed-orifice PCV valve design with a dynamic electrically controllable crankcase ventilation valve. This dynamic valve can adapt its opening degree to different operating conditions (idle, warm-up, cold weather), significantly improving adaptability while adding only moderate complexity through the incorporation of an electrically actuated mechanism and control system integration.
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 solution increases crankcase ventilation and oil separation efficiency, reduces fuel dilution, and ensures adequate engine performance during cold weather or short engine use by actively controlling ventilation flow rates, prioritizing crankcase ventilation when necessary.
Implementation Method 1
The electrically controlled crankcase ventilation valve may include a solenoid valve
Implementation Method 2
A large orifice is arranged in series with a variable pressure control valve
Data Source
AI summary
Methods and systems are provided for coordinating throttle bypass flows from brake booster vacuum reservoir, a fuel vapor purge system, and a crankcase ventilation system via active, electrical control of a crankcase ventilation valve. In one example, a method may include actively opening the crankcase ventilation valve to allow crankcase ventilation flow into the engine during conditions in which doing so will not result in engine air flow rate and/or engine fuel flow rate exceeding desired rates. Priority is given first to brake booster replenishment, then to fuel vapor purging, and then to crankcase ventilation during conditions where all three throttle bypass flows are desired.