Vehicle Valve Stop Control Apparatus Intake Pressure Management
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Solution Overview
Problem
During valve stop inertial running, excessive engine torque causes vibrations when the vehicle mode returns to valve operation running due to increased intake passage pressure, leading to deteriorated drivability.
Innovation Solution
A control apparatus that includes a valve stop mode control unit to stop intake and exhaust valves, control the throttle valve to idling or less, and sets the clutch engaged, along with an intake pressure control unit using a vacuum pump to supply negative pressure to the intake passage, reducing pressure and preventing excessive fuel supply during mode transition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fuel supply control supplies fuel according to increased intake passage pressure during mode transition, then fuel supply accuracy is improved, but excessive engine torque is generated causing vibrations
Solution Approach 1:
The control device performs preliminary action by detecting the valve stop running state and proactively reducing fuel supply amount before the mode transition completes. This prevents the intake passage pressure from causing excessive fuel injection, thereby avoiding vibrations while maintaining accurate fuel control during the transition to normal running state
Solution Approach 2:
The control device uses feedback by continuously monitoring the running state (valve stop vs. normal) and adjusting fuel supply amount accordingly. When valve stop running is detected, the fuel supply is reduced; when normal running is detected, fuel supply returns to standard levels, ensuring accurate fuel control without causing vibrations
2Use of energy by moving object
If valve stop inertial running is executed to improve fuel efficiency, then fuel consumption is reduced, but intake passage pressure increases causing drivability deterioration
Solution Approach 1:
The control device applies preliminary action by preemptively reducing fuel supply amount when valve stop running state is detected. This prevents the buildup of excessive intake passage pressure that would occur during mode transition, thereby maintaining smooth drivability while still achieving fuel efficiency benefits during valve stop inertial running
Solution Approach 2:
The control device changes the fuel supply parameter based on the running state. During valve stop running, fuel supply amount is reduced to a specific value lower than the standard amount corresponding to intake pressure, preventing drivability deterioration while maintaining fuel efficiency improvements
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 effectively suppresses vibrations caused by excessive engine torque by maintaining low intake passage pressure during mode transitions, improving drivability and fuel efficiency.
Implementation Method 1
an intake pressure control unit using a vacuum pump to supply negative pressure to the intake passage, reducing pressure and preventing excessive fuel supply during mode transition
Data Source
AI summary
A vehicle having a valve stop mode control unit configured such that an intake valve and an exhaust valve are stopped in a closed state during rotation of an output shaft, supply of fuel to an engine is stopped, a clutch is made to be in an engaged state, and pistons are driven by rotational forces from driving wheels through the output shaft. When there is a request for valve stop inertial running, a negative pressure is supplied to an intake passage by a vacuum pump.