Engine Cylinder Deactivation via Dynamic Intake Valve Control

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Solution Overview

Problem

Multi-cylinder internal combustion engines face significant pumping losses when deactivating cylinders to reduce fuel consumption, as keeping intake valves closed during intake stages leads to inefficient operation and increased energy loss.

Innovation Solution

Implementing a control system that keeps intake valves of deactivated cylinders partly open during the discharge stage to allow burnt gases to escape, then closes them before fresh air enters, minimizing pumping losses by controlling the intake valves electronically to manage cylinder deactivation and fuel supply.

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 pumping losses increase due to closed intake valves during intake stages

Engineering Contradiction:

Improvefuel consumptionVSAvoidpumping losses

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The intake valves of deactivated cylinders are kept dynamically open during the discharge stage instead of being statically closed, allowing burnt gases to escape into the intake conduit. This dynamic valve control reduces pumping losses while maintaining fuel efficiency benefits of cylinder deactivation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system maintains continuous useful action by allowing burnt gases to flow continuously from deactivated cylinders through open intake valves during the discharge stage, preventing energy loss and maintaining thermodynamic efficiency without requiring maximum power operation.

Inventive Principle:

Principle #20Continuity of useful action

2Device complexity

If intake valves are kept closed during intake stages in deactivated cylinders, then deactivation control is simplified, but thermodynamic efficiency deteriorates due to increased pumping losses

Engineering Contradiction:

Improvevalve control complexityVSAvoidpumping losses

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The valve control system transitions from a simple closed-state control to a dynamic control that keeps intake valves open during the discharge stage in deactivated cylinders. This dynamic approach reduces pumping losses while maintaining manageable system complexity through electronic control.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameter of intake valve position from purely closed to a variable state that remains open during the discharge stage. This parameter change optimizes thermodynamic efficiency by reducing pumping losses while maintaining deactivation control.

Inventive Principle:

Principle #35Parameter changes

3Power

If all cylinders are kept active to maintain power output, then power delivery is improved, but fuel consumption increases

Engineering Contradiction:

Improvepower outputVSAvoidfuel consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The engine system is segmented into active and deactivated cylinder groups, allowing selective operation. By deactivating specific cylinders while maintaining others active, the system reduces fuel consumption while maintaining sufficient power output for non-maximum load conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the number of active cylinders based on power demands. During non-maximum power conditions, some cylinders are deactivated with optimized valve control to reduce fuel consumption, while maintaining the ability to activate all cylinders when maximum power is required.

Inventive Principle:

Principle #15Dynamics

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 reduces fuel consumption while maintaining power output by minimizing pumping losses and optimizing thermodynamic efficiency, especially when only a subset of cylinders is deactivated.

Implementation Method 1

part of the burnt gases generated during the operation prior to the deactivation flows into the respective intake conduits (4) during the discharge stage of each cylinder

Methodology Applied

Scientific EffectGas flow:

Implementation Method 2

minimizing pumping losses by controlling the intake valves electronically to manage cylinder deactivation and fuel supply

Methodology Applied

Scientific EffectThermodynamic efficiency optimization:

Data Source

PatentUS8909460B2Internal combustion engine with cylinders that can be de-activated, with exhaust gas recirculation by variable control of the intake valves, and method for controlling an internal combustion engine

Publication Date: 2014.12.09 CENTRO RICERCHE FIAT SCPA

AI summary

A multi-cylinder internal combustion engine is provided with a system for the variable actuation of the intake valves. At least one part of the engine cylinders is deactivated, cutting off fuel supply to said cylinders, under operating conditions that do not require the maximum power of the engine and in which one wants to reduce fuel consumption. The intake valves of the deactivated cylinders are kept at least partly open during at least one part of the discharge stages in the deactivated cylinders, hence, in the deactivated cylinders, part of the burnt gases generated during the operation prior to the deactivation flows into the respective intake conduits during the discharge stage of each cylinder. The intake valves are closed after the discharge stage. The intake valves of the deactivated cylinders are further kept closed during the compression and expansion stages in each deactivated cylinder.