Sealed-Pore Sintered Alloy Valve Guide for High-Temperature Anti-Adhesion

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Solution Overview

Problem

Existing sintered alloy valve guides face issues with valve adhesion and abnormal wear in high-temperature environments due to lubricating oil leakage and reduced oil retention.

Innovation Solution

A sintered alloy valve guide with pores sealed on the outer circumferential surface is impregnated with lubricating oil, using a method that includes molding, sintering, impregnation, and sealing to retain the oil and prevent adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the compression ratio is increased to improve combustion efficiency, then fuel consumption and emissions are reduced, but engine temperature increases causing lubricating oil to leak out and valve adhesion occurs

Engineering Contradiction:
Improveexhaust lossVSAvoidvalve adhesion resistance
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The valve guide utilizes a sintered alloy structure with controlled porosity to retain lubricating oil within its matrix. The porous structure allows the material to absorb and hold oil, which then transfers to the valve surface during operation, providing continuous lubrication even at high temperatures where traditional oil delivery methods fail.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention changes the physical and chemical parameters of the valve guide material by using sintered alloy with specific density (6.55 g/cm³) and controlled pore structure. This material parameter change enables superior oil retention capability compared to traditional solid valve guides, allowing the system to maintain reliability under high-temperature conditions.

Inventive Principle:
Principle #35Parameter changes

2Strength

If silicone resin is impregnated into pores to reduce lubricating oil discharge, then wear resistance improves, but valve adhesion still occurs when lubricating oil amount is reduced

Engineering Contradiction:
Improvewear resistanceVSAvoidvalve adhesion resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The valve guide employs a sintered alloy structure with controlled porosity to retain lubricating oil within its matrix. The porous structure allows the material to absorb and hold oil, which then transfers to the valve surface during operation, providing continuous lubrication even at high temperatures where traditional oil delivery methods fail.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention uses a composite structure combining sintered alloy matrix with embedded lubricating oil. This composite approach creates a self-lubricating system where the porous sintered alloy acts as an oil reservoir, continuously supplying lubrication to prevent adhesion while maintaining wear resistance.

Inventive Principle:
Principle #40Composite materials

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 solution effectively inhibits valve adhesion and abnormal wear in high-temperature environments by retaining a sufficient amount of lubricating oil, thereby enhancing the wear resistance of the valve guide.

Implementation Method 1

a sintered alloy valve guide used in an internal combustion engine, and a method of producing the same... the density and the powder grain size of the sintered alloy are adjusted to control the air permeability in a specific range, and a silicone resin is impregnated into pores to attain excellent wear resistance and seizure resistance and to reduce the discharge of an impregnated lubricating oil

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

consequently discovered that the above-described problem can be solved by performing a sealing treatment of pores on the outer circumferential surface of a valve guide in a state where the valve guide retains the lubricating oil

Methodology Applied
Scientific EffectPore sealing:

Implementation Method 3

the sintering step of sintering the molded body... the valve guide prior to being impregnated with the lubricating oil preferably has a density of 6.55 g/cm³

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP4130444B1Sintered alloy valve guide, and method for manufacturing sintered alloy valve guide
Publication Date: 2025.04.16 TEIKOKU PISTON RING CO LTD
  • EP4130444B1 patent drawingFigure 1
  • EP4130444B1 patent drawingFigure 2
  • EP4130444B1 patent drawingFigure 3

AI summary

The present invention addresses the problem of providing a sintered alloy valve guide capable of inhibiting valve adhesion even in a high-temperature environment. The problem can be solved by a sintered alloy valve guide impregnated with a lubricating oil including pores that are sealed on the valve guide outer circumferential surface. More particularly, the problem is solved by the sealing step of performing a sealing treatment of pores on the outer circumferential surface of a sintered body impregnated with a lubricating oil.