Turbocharger Auxiliary Air Source for Low-Speed Cylinder Deactivation

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Solution Overview

Problem

Diesel engines face limitations in the operational range of cylinder deactivation (CDA) due to insufficient intake combustion air flow at low engine speeds and loads, which restricts the air-to-fuel ratio (AFR) below a threshold, limiting the efficiency and emissions compliance of CDA.

Innovation Solution

Integrating an auxiliary air source with a turbocharger to increase intake combustion air flow, using an electrically or mechanically driven mechanism to enhance the turbocharger's capability, thereby expanding the CDA operating range by maintaining an optimal AFR.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cylinder deactivation is used to improve fuel economy and emissions, then fuel economy and emissions compliance are improved, but the operational range is limited due to insufficient intake combustion air flow at low engine speeds and loads

Engineering Contradiction:

Improvefuel economyVSAvoidoperational range

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The auxiliary air source is activated before or during cylinder deactivation to pre-establish the necessary intake air flow conditions. This ensures that when cylinders are deactivated and displacement is reduced, sufficient air is already available to maintain proper air-to-fuel ratios and combustion efficiency across a broader operational range including low engine speeds and loads.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the air-to-fuel ratio parameter by introducing additional air through the auxiliary air source. This parameter change enables the engine to maintain optimal combustion conditions during cylinder deactivation across varying operating conditions, thereby expanding the operational range where CDA can be effectively applied.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the number of active cylinders is decreased to improve combustion efficiency, then combustion efficiency and fuel economy are improved, but intake combustion air flow becomes insufficient at low engine speeds and loads

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidintake combustion air flow

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The auxiliary air source acts as an intermediary component that bridges the gap between reduced cylinder displacement and required air flow. By introducing additional air through this intermediary system, the patent maintains sufficient intake combustion air flow even when the number of active cylinders is decreased, thereby preserving both combustion efficiency and adequate air supply.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The auxiliary air source is activated in advance or concurrently with cylinder deactivation to pre-establish the necessary air flow conditions. This preliminary action ensures that when cylinders are deactivated, the air flow requirement is already met through the combined output of the turbocharger and auxiliary air source.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the air-to-fuel ratio is increased to maintain efficiency during CDA, then combustion efficiency is improved, but additional air flow is required that exceeds turbocharger capability at low engine speeds and loads

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidintake air flow capability

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The patent combines the output of two air delivery systems: the turbocharger and the auxiliary air source. This merging of capabilities allows the system to achieve the higher air flow rates necessary for maintaining optimal air-to-fuel ratios during cylinder deactivation, particularly at low engine speeds and loads where the turbocharger alone would be insufficient.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

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

The auxiliary air source enables CDA operation at low engine speeds and above low engine loads, enhancing combustion efficiency and fuel economy while ensuring emissions compliance by maintaining an optimal AFR.

Implementation Method 1

a turbocharger operative to receive exhaust gas from the diesel engine and supply charged intake air to the diesel engine

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

sending at least one signal to cause an auxiliary air source integrated with a turbocharger to add torque to a shaft of the turbocharger

Methodology Applied

Scientific EffectTorque: Torque

Data Source

PatentUS12523184B2Cylinder deactivation expanded operational range with additional air source integrated with turbocharger

Publication Date: 2026.01.13 PACCAR INC

AI summary

Providing additional mass air flow to an engine of a vehicle to expand an operating range of cylinder deactivation (CDA) is provided. Aspects of the present disclosure describe a method and system to provide additional mass air flow to an engine using an auxiliary air source coupled to a turbocharger. When a low air-to-fuel ratio state is determined in association with operating the vehicle in CDA mode, the auxiliary air source is activated to assist the turbocharger with increase the supply of supercharged intake air to the engine. Accordingly, the operating range of CDA is expanded.