Variable Compression Engine Lubrication Using Piston Position Feedback

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Solution Overview

Problem

Existing engine systems with variable compression mechanisms face challenges in ensuring consistent lubricating fluid supply to the cylinder, particularly when the compression ratio changes, leading to potential insufficient lubrication.

Innovation Solution

An engine system equipped with a fluid chamber, a supply device for lubricating fluid, a detection device for piston position information, and a control device that adjusts the lubricating fluid supply timing and amount based on the piston's position, ensuring consistent lubrication across varying compression ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the compression ratio is changed by moving the piston rod, then the compression ratio is adjusted, but the supply position of the lubricating fluid varies causing insufficient lubrication

Engineering Contradiction:
Improvecompression ratio adjustmentVSAvoidlubricating fluid supply consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The lubricating fluid supply timing is made dynamic by adjusting it according to the piston rod position. The control device changes the supply timing based on the detected piston position, ensuring that lubrication is consistently supplied to the cylinder regardless of compression ratio changes. This dynamic adjustment resolves the contradiction by making the supply system adaptive to position changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A detection device detects the piston rod position and provides feedback to the control device, which then adjusts the lubricating fluid supply timing accordingly. This feedback mechanism ensures that the supply position remains consistent even when the compression ratio changes, resolving the reliability issue while maintaining adaptability.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the piston rod position is fixed, then the lubricating fluid supply timing is simple, but the compression ratio cannot be adjusted

Engineering Contradiction:
Improvesupply timing controlVSAvoidcompression ratio variability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system transitions from a fixed supply timing to a dynamic supply timing that adjusts with piston rod position. The control device modifies the supply timing based on detected position, enabling compression ratio adjustment while maintaining manageable complexity through automated control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses the detection device to automatically detect piston position and the control device to automatically adjust supply timing without manual intervention. This self-adjusting mechanism handles the complexity of variable compression ratio control while maintaining lubrication consistency.

Inventive Principle:
Principle #25Self-service

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 system ensures reliable and consistent lubrication by synchronizing the lubricating fluid supply with the piston's position, maintaining optimal lubrication even at high compression ratios, thus preventing insufficient lubrication.

Implementation Method 1

a fluid chamber to which a pressurized working fluid is supplied so that a piston rod connected to a piston is moved in a high compression ratio direction

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the detection device may be configured to have a sensor unit that detects a movement of a detection target fixed to the piston rod in a non-contact manner

Methodology Applied
Scientific EffectNon-contact detection:

Data Source

PatentEP3722574B1Engine system
Publication Date: 2022.12.07 IHI CORP
  • EP3722574B1 patent drawingFigure 1
  • EP3722574B1 patent drawingFigure 2
  • EP3722574B1 patent drawingFigure 3~5

AI summary

An engine system includes a variable compression device having a fluid chamber to which a pressurized working fluid is supplied so that a piston rod connected to a piston is moved in a high compression ratio direction, a supply device that supplies a lubricating fluid to a cylinder portion on which the piston slides, a detection device that outputs a signal including position information of the piston, and a control device that controls the supply device based on the signal.