Engine Cylinder Deactivation via Intake Valve Timing Advancement

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Solution Overview

Problem

Existing engine systems face challenges in efficiently deactivating cylinders to conserve fuel while maintaining engine torque, as continuous air flow through deactivated cylinders can degrade exhaust gas aftertreatment system performance and increase noise, vibration, and harshness.

Innovation Solution

The method involves holding exhaust valves closed and operating intake valves during engine rotation, while advancing intake valve timing to reduce intake manifold pressure pulsations, thereby preventing air flow through deactivated cylinders and improving engine efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If intake valves and exhaust valves of deactivated cylinders continue to operate while combustion is ceased, then air flow through deactivated cylinders can be maintained, but oxygen is pumped to the exhaust gas after treatment system which degrades its performance

Engineering Contradiction:

Improveexhaust gas after treatment system performanceVSAvoidoxygen flow to exhaust system

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent extracts the harmful function (oxygen pumping) from the deactivated cylinder by closing the exhaust valve, while maintaining the beneficial function (intake valve operation) to prevent harmful air flow accumulation. This selective valve control removes the problematic oxygen flow to the aftertreatment system without requiring complete valve deactivation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different operational states to different valves within the same cylinder - the exhaust valve is closed while the intake valve continues to operate. This local differentiation allows the system to prevent harmful oxygen flow through the exhaust path while maintaining intake functionality, resolving the contradiction between maintaining air flow and preventing oxygen pumping.

Inventive Principle:

Principle #3Local quality

2Productivity

If all intake and exhaust valves of deactivated cylinders are held closed to stop air flow, then oxygen pumping to exhaust system is prevented, but manufacturing cost becomes prohibitive

Engineering Contradiction:

Improveexhaust gas after treatment system performanceVSAvoidvalve control system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies partial action by closing only the exhaust valve of deactivated cylinders while leaving the intake valve operational. This partial deactivation is sufficient to prevent harmful oxygen flow to the aftertreatment system, while avoiding the excessive complexity and cost of completely deactivating both valves or implementing full cylinder deactivation systems.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the operational parameter of the exhaust valve from open to closed state in deactivated cylinders, while maintaining the intake valve in its operational state. This parameter change selectively prevents oxygen pumping without requiring complete valve deactivation, thereby reducing system complexity and manufacturing costs while maintaining aftertreatment performance.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If intake valves of deactivated cylinders continue to operate with exhaust valves closed, then air flow through deactivated cylinders increases, but intake manifold pressure pulsations increase causing noise and vibration

Engineering Contradiction:

Improveair flow through deactivated cylindersVSAvoidintake manifold pressure pulsations

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful effect of increased air flow through deactivated cylinders into a beneficial outcome by carefully controlling exhaust valve timing. The closed exhaust valve prevents oxygen from reaching the aftertreatment system, while the controlled air flow through the cylinder is used to maintain engine braking effects and reduce overall intake manifold pressure variations, thereby reducing noise and vibration.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Use of energy by moving object

If cylinder deactivation is implemented to conserve fuel, then fuel consumption is reduced, but exhaust gas after treatment system efficiency degrades due to excess oxygen

Engineering Contradiction:

Improvefuel consumptionVSAvoidexhaust gas after treatment system efficiency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent segments the valve control functions within deactivated cylinders, applying different control strategies to intake and exhaust valves. The exhaust valve is closed to prevent oxygen flow to the aftertreatment system, while the intake valve continues to operate to maintain proper air management. This segmentation allows fuel savings from cylinder deactivation while preserving aftertreatment system efficiency.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10107208B2System and method to operate an engine

Publication Date: 2018.10.23 FORD GLOBAL TECH LLC

AI summary

Systems and methods for controlling operation of deactivated engine cylinders are presented. In one example, intake valve timing of deactivated engine cylinders is advanced to reduce amplitudes of intake pressure pulsations while exhaust valves of the deactivated engine cylinders are held closed. Further, intake valve timing of deactivated cylinders may be advanced responsive to output of an intake manifold pressure sensor.