Connecting Rod Check Valve Captive Element Design

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Solution Overview

Problem

Internal combustion engines with fixed compression ratios face inefficiencies during part-load operations due to the inability to adjust compression ratios without causing engine knocking, limiting the potential for improved efficiency in the partial load range.

Innovation Solution

A connecting rod with a check valve featuring a pin-shaped captive element that secures the valve closing body within the valve housing, allowing for cost-effective design and reduced flow resistance, enabling adjustable compression ratios without hydraulic fluid backflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional check valve with sealing cover is used to secure the valve closing body, then the valve closing body is reliably secured, but the flow resistance increases and manufacturing costs rise

Engineering Contradiction:
Improvesecuring of valve closing bodyVSAvoidmanufacturing cost and assembly effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and removes the sealing cover component from the conventional check valve design. Instead of using a separate sealing cover to secure the valve closing body, the valve housing itself is designed with an integrated retaining structure that directly holds the valve closing body, eliminating the need for the additional sealing cover component and reducing assembly complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the functions of the valve housing and the securing mechanism into a single integrated structure. The valve housing incorporates retaining elements (such as retaining ribs or integrated retention features) that directly secure the valve closing body, combining what were previously separate components (valve housing + sealing cover) into one unified structure, thereby reducing part count and manufacturing cost

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a sealing cover is used to secure the valve closing body, then the valve is reliably assembled, but the flow resistance increases when the valve is open

Engineering Contradiction:
Improveassembly reliabilityVSAvoidflow resistance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sealing cover is extracted and removed from the design. The valve closing body is secured directly within the valve housing using integrated retaining features, eliminating the physical barrier that the sealing cover would create to hydraulic fluid flow, thereby reducing flow resistance while maintaining securing reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a separate cover element to secure the valve closing body from the outside, the invention inverts the approach by having the valve housing itself provide internal retaining structures (such as retaining ribs or integrated features) that secure the valve closing body from within, allowing unobstructed fluid flow paths

Inventive Principle:
Principle #13The other way round (Inversion)

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 enables a cost-effective and efficient adjustment of compression ratios, reducing production costs and assembly effort while maintaining hydraulic fluid flow, thus enhancing engine efficiency across various load ranges.

Implementation Method 1

the check valve comprises a valve housing and a valve closing body that can be displaced axially in the valve housing along a longitudinal valve axis

Methodology Applied
Scientific EffectCheck valve mechanism: Valve

Implementation Method 2

the captive element securing the valve closing body in the valve housing and limiting a stroke of the valve closing body

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Fastener

Data Source

PatentEP3361069B1Connecting rod of a combustion engine with variable compression with a check valve
Publication Date: 2019.12.25 ECO HLDG 1 GMBH
  • EP3361069B1 patent drawingFigure 1
  • EP3361069B1 patent drawingFigure 2~5

AI summary

The invention relates to a connecting rod (1) for a variable-compression internal combustion engine with at least one hydraulic chamber (4, 5) which can be connected to a supply port, a bearing shell, or a tank of the connecting rod (1) by means of a check valve (9, 10), wherein the check valve (9, 10) comprises a valve housing (21) and a valve closing element (22) which is axially displaceable in the valve housing along a longitudinal axis (L) of the valve and which can be positioned against a valve seat (23) and is arranged in the valve housing in a captive manner. According to the invention, a pin-shaped anti-capture element (24) is provided which secures the valve closing element (22) in the valve housing (21) and limits a stroke (33) of the valve closing element (22).