Variable Valve Timing Control for Foreign Object Removal

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Solution Overview

Problem

In hybrid vehicles equipped with variable valve timing mechanisms, intermittent engine operation control can lead to engine stalling during foreign object removal processes, which complicates failure judgment and increases costs, especially when the engine is stopped mid-process, and existing solutions are inadequate for vehicles that actively stop engine operation to improve fuel efficiency.

Innovation Solution

An engine control device that judges abnormalities in the variable valve timing mechanism and prohibits intermittent operation control during the abnormality recovery process, allowing for the completion of foreign object removal without engine shutdown, by alternately rotating the rotor to the advance or lag angle and maintaining higher hydraulic pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If intermittent operation control is executed to improve fuel consumption, then fuel efficiency is improved, but the engine may stop during foreign object removal process causing failure judgment

Engineering Contradiction:

Improvefuel consumptionVSAvoidfailure judgment accuracy

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The control device prohibits intermittent operation control before the foreign object removal process completes. By detecting that the engine is in the middle of foreign object removal (through monitoring camshaft phase angle adjustments), the system prevents engine shutdown in advance, ensuring the removal process can complete successfully without interruption.

Inventive Principle:

Principle #10Preliminary action

2Loss of energy

If engine is stopped during foreign object removal process, then fuel consumption is reduced, but the removal process cannot be properly executed

Engineering Contradiction:

Improveenergy loss during removal processVSAvoidforeign object removal completion

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The control device detects the foreign object removal process status by monitoring camshaft phase angle changes and prohibits engine shutdown before removal completes. This preliminary prevention ensures the removal process has sufficient time and uninterrupted operation to successfully remove foreign objects.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device dynamically adjusts engine operation status based on real-time detection of foreign object removal progress. By continuously monitoring camshaft phase angle and comparing it with expected values, the system dynamically prohibits or permits intermittent operation control to match the current operational state.

Inventive Principle:

Principle #15Dynamics

3Loss of time

If foreign object removal process is executed with time limit, then compliance with laws is improved, but premature failure judgment occurs when engine stops mid-process

Engineering Contradiction:

Improvetime limit for removal processVSAvoidfailure judgment accuracy

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

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

Prevents engine stalling during foreign object removal, ensuring reliable recovery of the variable valve timing mechanism and preventing premature failure judgment, thus reducing costs and compliance with time-sensitive degradation laws.

Implementation Method 1

when hydraulic control is used for changing the phase angle of the cam shaft

Methodology Applied

Scientific EffectHydraulic control: Hydraulic Press

Implementation Method 2

lubricant oil which is used for lubricating a piston or power transmission system in the engine

Methodology Applied

Scientific EffectLubrication: Lubrication

Data Source

PatentUS8483938B2Control device for an engine

Publication Date: 2013.07.09 TOYOTA JIDOSHA KK

AI summary

In an engine having a variable valve timing mechanism to which an intermittent operation control is applied, appropriate execution of a foreign object removal process for the variable valve timing mechanism is enabled. An engine control device (16) which can execute intermittent operation control for an engine (12) having a variable valve timing mechanism (80) comprises a judging part which judges an abnormality in the variable valve timing mechanism (80) (step S10), a foreign object removal process executing part which causes a foreign object removal process to be executed for the variable valve timing mechanism (80) when the judging part judges that there is an abnormality in the variable valve timing mechanism (80) during an engine operation (step S12), and an intermittent operation control prohibiting part which prohibits the intermittent operation control of the engine (12) during execution of the foreign object removal process of the variable valve timing mechanism (80) (step S16).