Turbocharger Turbine Housing Segmentation for Casting Formability

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Solution Overview

Problem

Downsizing turbochargers poses challenges in forming the inner wall shape of the turbine housing, particularly in the throat portion of the scroll flow passage, which has a smaller width, leading to decreased formability and feasibility of the core.

Innovation Solution

A turbine housing configuration where the throat forming portion is a separate piece from the main housing, forming the hub-side and shroud-side wall surfaces of the throat portion, and a heat shield portion with interposed gaps between heat-shielding plates to suppress heat radiation, enhancing formability and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the turbocharger is downsized, then the size of the turbocharger is reduced, but the formability of the inner wall shape of the turbine housing decreases

Engineering Contradiction:
Improvesize of turbochargerVSAvoidformability of inner wall shape
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The turbine housing is divided into two separate parts: the main turbine housing and the throat forming portion. The throat forming portion is provided as a separate piece that can be attached to the turbine housing. This segmentation allows the complex throat portion with small axial width to be formed independently, improving core formability during casting while enabling overall turbocharger downsizing.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If the throat portion width is reduced for downsizing, then the turbocharger size is reduced, but the feasibility of the core for casting decreases

Engineering Contradiction:
Improvethroat portion widthVSAvoidcore feasibility
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The throat forming portion is separated from the main turbine housing and provided as an independent component. This allows the throat portion to be formed with appropriate dimensions for core feasibility while the overall turbocharger size is reduced. The separate throat forming portion can be designed with optimal geometry for casting core formation.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the throat forming portion is made as a separate piece, then the formability of the inner wall shape is improved, but the device complexity increases

Engineering Contradiction:
Improveformability of inner wall shapeVSAvoidnumber of parts
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The turbine housing is segmented into the main housing and the throat forming portion. While this increases the number of parts, it significantly improves manufacturability by enabling core formation for the complex throat geometry. The separate throat forming portion can be manufactured independently and attached to the main housing, facilitating mass production and quality control.

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

Facilitates the formation of the inner wall shape during casting, improves formability, and reduces heat radiation, thereby enhancing the turbocharger's efficiency and durability.

Implementation Method 1

a heat shield portion positioned on an opposite side of the outlet portion in an axial direction across at least one of the turbine impeller or a scroll flow passage communicating with the turbine impeller

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Data Source

PatentEP3705699B1Turbine and turbocharger comprising same
Publication Date: 2023.04.26 MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD
  • EP3705699B1 patent drawingFigure 1
  • EP3705699B1 patent drawingFigure 2
  • EP3705699B1 patent drawingFigure 3

AI summary

A turbine includes a turbine impeller, a turbine housing disposed so as to cover the turbine impeller and internally forming a scroll flow passage through which an exhaust gas flows, and a throat forming portion which is provided as a separate piece from the turbine housing. The throat forming portion is disposed to face a section of the turbine housing and forms a hub-side wall surface of a throat portion of the scroll flow passage in an axial direction, the section forming a shroud-side wall surface of the throat portion.