Cylinder Liner Inner Diameter Reduction via Thermal Deformation

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Solution Overview

Problem

Conventional methods for repairing cylinder liners do not allow them to be reused in machines with the same inner diameter dimensional requirements, as they increase the inner diameter during remanufacturing, making them unsuitable for original applications.

Innovation Solution

A method and apparatus that involves placing a cylinder liner into a confinement with a cavity of matching outer diameter, heating it to induce plastic deformation, and cooling it to reduce the inner diameter, allowing for machining and reuse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If conventional remanufacturing methods (honing/grounding) are used to repair cylinder liners, then the inner surface can be restored, but the inner diameter increases and the liner cannot be reused in machines requiring original dimensional specifications

Engineering Contradiction:

Improvecylinder liner repairabilityVSAvoidinner diameter dimensional specification

Core Design Contradiction:

Ease of repairVSManufacturing precision

Solution Approach 1:

The patent applies thermal parameters (heating to austenite temperature range) and mechanical pressure parameters during forming to change the physical state and dimensions of the cylinder liner. Heating transforms the material structure while confining pressure induces plastic deformation that reduces the inner diameter, allowing restoration of original dimensional specifications after machining.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes thermal expansion by heating the cylinder liner to the austenite temperature range, causing the material to expand and become more formable. This thermal state change enables subsequent plastic deformation under confining pressure to effectively reduce the inner diameter, which would not be achievable at ambient temperature.

Inventive Principle:

Principle #37Thermal expansion

2Ease of repair

If material is removed from the inner diameter through honing or grinding, then the worn surface is restored, but additional material is lost and the inner diameter increases beyond original specifications

Engineering Contradiction:

Improveworn surface restorationVSAvoidmetal material loss

Core Design Contradiction:

Ease of repairVSLoss of substance

Solution Approach 1:

Instead of continuously removing material to restore the surface (conventional approach), the patent inverts the approach by first adding material through plastic deformation (forming process that increases wall thickness), then removing a controlled amount through machining to achieve the target dimension. This ensures the final inner diameter does not exceed original specifications.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent recovers the cylinder liner from wear damage by restoring its dimensional integrity. Although some material is removed during the final machining operation, the overall process recovers the liner's service life by restoring it to original specifications, preventing the complete loss of the component.

Inventive Principle:

Principle #34Discarding and recovering

3Shape

If the cylinder liner is heated to cause plastic deformation, then the inner diameter can be reduced, but the material structure must be transformed to austenite phase

Engineering Contradiction:

Improveinner diameter reductionVSAvoidheating to austenite temperature

Core Design Contradiction:

ShapeVSTemperature

Solution Approach 1:

The patent exploits the phase transition of the cylinder liner material to the austenite phase through controlled heating. This phase transition occurs at a specific temperature range and transforms the material structure, making it more ductile and formable. The phase transition is essential for enabling the plastic deformation that reduces the inner diameter.

Inventive Principle:

Principle #36Phase transitions

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

Enables the cylinder liner to be reused with a reduced inner diameter, providing additional material for machining to meet specification requirements, while accommodating manufacturing tolerances and maintaining structural integrity.

Implementation Method 1

heating it to induce plastic deformation

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

heating the cylinder liner to a temperature at which the cylinder liner undergoes plastic deformation

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10060529B2Method and apparatus for repairing cylinder liners

Publication Date: 2018.08.28 CATERPILLAR INC

AI summary

A method for repairing a cylinder liner includes: placing a cylinder liner having a first inner diameter and a first outer diameter into a cavity of a confinement, the cavity including a cavity inner diameter that is substantially the same as the first outer diameter of the cylinder liner; heating the cylinder liner to a temperature at which the cylinder liner undergoes plastic deformation, causing the first inner diameter of the cylinder liner to decrease; and cooling the cylinder liner. The cooled cylinder liner has a second inner diameter that is less than the first inner diameter. An apparatus for repairing a cylinder liner includes a confinement having a cavity and a fluid passageway for controlling the temperature of the confinement, and a heating block for heating the cylinder liner when the cylinder liner is inserted into the cavity.