Turbocharger Inlet Port Wall Thickness Design

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Solution Overview

Problem

Internal combustion engine inlet ports experience reduced strength due to high-temperature exhaust gas exposure, leading to strain on peripheral components like catalytic converters, as existing reinforcement methods uniformly increase rigidity, causing uneven thermal expansion stress.

Innovation Solution

The design incorporates a turbocharger inlet port with a thick-walled portion for high-temperature reinforcement and a thin-walled portion upstream to absorb thermal expansion stress, while maintaining coolant proximity to reduce temperature and maintain strength, and a gradual thickness transition to minimize stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rigidity of the inlet port is uniformly increased by providing a reinforcing portion, then the strength of the inlet port is improved, but the strain on peripheral members increases

Engineering Contradiction:

Improvestrength of inlet portVSAvoidstrain on peripheral member

Core Design Contradiction:

StrengthVSStress or pressure

Solution Approach 1:

The inlet port is designed with non-uniform wall thickness, featuring a thick-walled portion at the location most exposed to high-temperature exhaust gas and a thin-walled portion upstream. This local differentiation allows the thick-walled section to provide necessary strength and heat resistance where needed, while the thin-walled section accommodates thermal expansion with less constraint, thereby reducing strain on peripheral members.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The wall thickness parameter of the inlet port is varied along its length to optimize performance. The thick-walled portion (with greater pipe wall thickness) is positioned at the high-temperature exposure zone to maintain strength, while the thin-walled portion (with smaller pipe wall thickness) is positioned upstream to allow thermal expansion, thus resolving the contradiction between strength and strain reduction.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the pipe wall thickness is increased to resist high temperature, then the strength is improved, but the thermal expansion stress becomes uneven

Engineering Contradiction:

Improvepipe wall strengthVSAvoiduniformity of thermal expansion

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

Different sections of the inlet port have different wall thicknesses tailored to their specific thermal and mechanical requirements. The thick-walled portion resists high temperature and maintains structural integrity, while the thin-walled portion allows for uniform thermal expansion, preventing stress concentration and deformation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The inlet port is segmented into distinct thick-walled and thin-walled portions, each serving a specific function. This segmentation allows the structure to handle both high-temperature resistance and thermal expansion uniformly, avoiding the problems of uneven stress distribution that would occur with uniform wall thickness.

Inventive Principle:

Principle #1Segmentation

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 configuration ensures sufficient strength of the inlet port and reduces strain on peripheral members by concentrating thermal expansion stress within the inlet port, preventing deformation and protecting connected components.

Implementation Method 1

the temperature of a continuous portion extending from a collector of the exhaust manifold to a portion that defines a turbine scroll passage, that is, an inlet port of the turbocharger, is likely to become particularly high. Thus, in the turbocharger according to JP 2013-189921 A, in order to reduce strain due to the thermal expansion of the inlet port

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the thin-walled portion is smaller in pipe wall thickness than the thick-walled portion. The thin-walled portion is located upstream of the thick-walled portion in a direction of exhaust gas flow

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10107181B2Internal combustion engine

Publication Date: 2018.10.23 TOYOTA JIDOSHA KK

AI summary

An internal combustion engine includes: a cylinder block including multiple cylinders; a cylinder head; and a turbocharger including an inlet port connected to an exhaust outlet of the cylinder head. The inlet port includes a first wall portion located between one cylinder out of the two outermost cylinders and the central axis of the inlet port in the cylinder array direction, and a second wall portion located on the opposite side of the central axis of the inlet port from the first wall portion. The first wall portion includes a thick-walled portion that is greater in thickness than the second wall portion, and a thin-walled portion that is smaller in thickness than the thick-walled portion and is located upstream of the thick-walled portion in the direction of exhaust gas flow.