Variable Displacement Engine Valve Deactivation Sequence

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Solution Overview

Problem

Engines operating in variable displacement modes face inefficiencies due to engine pumping losses and oil consumption, despite cylinder deactivation techniques, as existing methods do not optimally manage valve deactivation sequences to minimize these issues.

Innovation Solution

The method involves deactivating the intake valve before the exhaust valve in certain conditions to reduce engine pumping losses and deactivating the exhaust valve before the intake valve in other conditions to minimize oil consumption, allowing for selective achievement of improved efficiency and reduced oil use based on engine operating modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If cylinders are deactivated to reduce fuel consumption, then fuel efficiency is improved, but engine pumping losses increase

Engineering Contradiction:

Improvefuel consumptionVSAvoidpumping losses

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by deactivating the intake valve before the exhaust valve during cylinder deactivation. This preliminary closure of the intake valve prevents air from entering the cylinder during the exhaust stroke, thereby reducing the volume of air that must be pumped out and reducing pumping losses while maintaining the fuel efficiency benefits of cylinder deactivation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of valve deactivation sequence from the conventional order (exhaust valve first) to an inverted order (intake valve first). This parameter change fundamentally alters the pressure dynamics within the cylinder during deactivation, reducing pumping losses while maintaining fuel economy improvements

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If cylinders are deactivated for extended periods, then fuel efficiency is improved, but engine oil consumption increases

Engineering Contradiction:

Improvefuel efficiencyVSAvoidoil consumption

Core Design Contradiction:

Use of energy by moving objectVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by deactivating the exhaust valve before the intake valve during extended cylinder deactivation periods. This sequence maintains higher pressure within the cylinder by preventing air ingress through the intake valve, which in turn reduces oil consumption while preserving the fuel efficiency benefits of extended cylinder deactivation

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If conventional valve deactivation sequence is used, then implementation is simple, but engine efficiency and oil consumption are not optimally managed

Engineering Contradiction:

Improveimplementation simplicityVSAvoidengine efficiency

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the valve deactivation sequence adaptive rather than fixed. The control system dynamically adjusts the valve deactivation order based on real-time engine operating conditions, allowing the system to optimize between fuel efficiency and oil consumption management while maintaining relatively simple implementation through existing valve control mechanisms

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11788480B2System and method for deactivating engine cylinders

Publication Date: 2023.10.17 FORD GLOBAL TECH LLC

AI summary

Systems and methods for determining which of an intake valve and an exhaust valve is to be deactivated first when an engine is operated in a variable displacement mode. In one example, an exhaust valve of the cylinder is deactivated before an intake valve of the cylinder when the engine is operated in a static variable displacement operating mode.