Vehicle Vacuum Pressure Control via Intake Valve Timing
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Solution Overview
Problem
Conventional methods for generating sufficient vacuum pressure for vehicle braking, such as using electric or mechanical vacuum pumps, lead to increased costs and reduced fuel efficiency, and alternative controls like IVC advance and A/C cut result in unstable idling and cooling performance due to inconsistent vacuum pressure management.
Innovation Solution
A method that dynamically controls the valve control system, air conditioner, and alternator to manage engine and booster vacuum pressures, ensuring sufficient vacuum for braking without excessive pump usage, by performing intake valve closing, A/C cut, or alternator control only when necessary, and employing low vacuum assist when other controls fail.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vacuum pump is used to generate sufficient vacuum pressure for braking, then vacuum pressure is ensured, but cost increases (electric vacuum pump) or fuel efficiency deteriorates (mechanical vacuum pump)
Solution Approach 1:
The engine's intake system itself is utilized to generate vacuum pressure during deceleration and idle states, eliminating the need for external vacuum pumps. The engine's natural intake vacuum during these states is harnessed to provide braking vacuum pressure, making the system self-sufficient without additional energy-consuming components.
Solution Approach 2:
The invention dynamically adjusts valve timing parameters (intake valve closing advance) to optimize vacuum pressure generation. By changing the valve timing parameters based on engine operating conditions, the system maximizes vacuum pressure during deceleration and idle states without requiring additional energy input.
2Reliability
If IVC advance control or A/C cut control is performed to reduce engine idle load, then vacuum pressure is improved, but unstable idling or cooling performance deterioration occurs due to excessive control frequency
Solution Approach 1:
The system continuously monitors vacuum pressure levels and engine operating conditions, and only activates IVC advance control or A/C cut control when vacuum pressure falls below predetermined thresholds during deceleration or idle states. This feedback-based selective activation prevents excessive control frequency while ensuring vacuum pressure is maintained when necessary.
Solution Approach 2:
The control strategy dynamically adapts to engine operating conditions by selectively applying IVC advance or A/C cut only during deceleration and idle states when vacuum pressure is needed, rather than applying continuous control. This dynamic approach maintains idling stability while providing vacuum pressure when required.
3Reliability
If IVC advance control or A/C cut control is excessively performed, then vacuum pressure is improved, but cooling performance deteriorates
Solution Approach 1:
The system monitors both vacuum pressure levels and A/C system status, and only implements A/C cut control when vacuum pressure is insufficient and cooling demand is low. This selective feedback control ensures vacuum pressure is maintained while preventing excessive A/C cut frequency that would deteriorate cooling performance.
Solution Approach 2:
The control strategy dynamically adjusts A/C compressor operation based on real-time vacuum pressure requirements and cooling demands. By adapting A/C cut control to actual system needs rather than applying it continuously, the system maintains cooling performance while providing sufficient vacuum pressure for braking.
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 ensures stable vacuum pressure for braking while reducing the need for vacuum pumps, preventing unstable idling and cooling issues, and improving fuel efficiency by minimizing unnecessary system operations.
Implementation Method 1
controlling the valve control system when the valve control system is operable, and controlling an air conditioner (A/C) or an alternator of the vehicle when the valve control system is inoperable. The controlling the valve control system may be performed for intake valve closing (IVC) advance control of the valve control system.
Implementation Method 2
a booster that amplifies the force applied to the brake pedal using the difference between the negative pressure (vacuum pressure) generated in an engine and the atmospheric pressure
Implementation Method 3
a master cylinder that switches the force applied to the brake pedal to a hydraulic pressure
Implementation Method 4
a brake that substantially generates the braking force by the hydraulic pressure supplied from the master cylinder
Data Source
AI summary
A method of controlling vacuum pressure for vehicle braking may include checking whether a vehicle is idle or enters a deceleration state, comparing an engine vacuum pressure and a booster vacuum pressure of the vehicle with a preset reference value, checking whether a valve control system of the vehicle is operable when the engine vacuum pressure and the booster vacuum pressure are lower less than the preset reference value, controlling the valve control system when the valve control system is operable; and controlling an air conditioner (A/C) or an alternator of the vehicle when the valve control system is inoperable.