Cylinder Liner Protrusion Layout for Void-Resistant Insert Casting

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Solution Overview

Problem

The joining strength between a cylinder liner and a cylinder block is insufficient due to voids formed at the joint portion, particularly in gravity casting and low-pressure permanent mold casting, where the casting material fails to adequately distribute to protrusion-to-protrusion areas on the outer periphery of the cylinder liner.

Innovation Solution

The cylinder liner features a specific arrangement of protrusions on its outer periphery, with a molten metal running index (YI) between 2.2 and 14.5, controlling the distance between adjacent protrusions, the area of top portions, and the space between them, ensuring effective distribution of molten metal and reducing voids at the interface with the cylinder block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If protrusions are provided on the outer periphery of the cylinder liner to improve joining strength, then the joining strength with the cylinder block is improved, but voids are formed at the joint portion due to insufficient distribution of casting material

Engineering Contradiction:
Improvejoining strengthVSAvoidvoid formation
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the geometric parameters of the protrusions by introducing the molten metal running index YI, which combines the distance between adjacent protrusions (P), the area of top portions (St), and the space between top portions (V). By optimizing these parameters within specific ranges (YI: 2.2-14.5, St: 8-35%, Pav: 0.7-2.3mm), the casting material can adequately fill the protrusion-to-protrusion areas while maintaining strong joining strength, preventing void formation at the joint portion.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the distance between adjacent protrusions is reduced to improve metal distribution, then the joining strength is improved, but the area of top portions decreases reducing the mechanical interlocking

Engineering Contradiction:
Improvecasting material distributionVSAvoidmechanical interlocking
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The invention optimizes the balance between distance between protrusions (P) and area of top portions (St) through the molten metal running index YI = P² × St / V. This parameter combination ensures that even when protrusions are closely spaced (small P), sufficient top portion area (St) is maintained to provide mechanical interlocking, while the small spacing allows adequate casting material distribution to fill the spaces between protrusions.

Inventive Principle:
Principle #35Parameter changes

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 arrangement enhances the joining strength between the cylinder liner and the cylinder block by minimizing voids and improving heat transfer, even in challenging casting methods like gravity casting.

Implementation Method 1

the casting material poured into the mold is sometimes not sufficiently distributed to a protrusion-to-protrusion area on the outer periphery of the cylinder liner base. Such phenomena particularly tend to occur when gravity casting or low-pressure permanent mold casting is carried out

Methodology Applied
Scientific EffectMolten metal flow:

Implementation Method 2

improve the joining strength and adhesion with a cylinder block by focusing on protrusions having a constricted shape

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3957415B1Cylinder liner for insert casting
Publication Date: 2023.08.09 TEIKOKU PISTON RING CO LTD
  • EP3957415B1 patent drawingFigure 1
  • EP3957415B1 patent drawingFigure 2
  • EP3957415B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a cylinder liner for insert casting that can improve the joining strength between a cylinder liner and a cylinder block by reducing voids generated between the cylinder liner and the cylinder block. The above-described problem can be solved when the molten metal running index YI defined by the following Formula (1) is from 2.2 to 14.5. MoltenmetalrunningindexYI=arearatioSt%oftopportionsofprotrusions×moltenmetalinfiltrationvolumeVmm3/surfaceareaAmm2ofcylinderlinerbase/averagesurface-to-surfacedistancePavbetweentopportionsofprotrusionsmm