Engine Block Seal with Inclined Core for Uniform Contact Pressure

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Solution Overview

Problem

Seals between engine blocks and weakly rigid components face challenges in maintaining optimal and durable sealing due to deformation issues caused by temperature changes and vibrations, with existing solutions struggling to balance elastic recovery and compressive strength, leading to uneven contact pressure and potential leaks.

Innovation Solution

A seal design featuring a rigid and inclined core with extensions at contact zones, allowing for adjustable compressive strength and improved elastic recovery, ensuring homogeneous contact pressure across the joint circumference, using a single thickness of material and incorporating elastomeric coatings for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the number of sealing ribs is multiplied to improve elastic recovery, then the contact pressure is divided and deformation amplitude is reduced, but the compressive strength of the seal is increased which can be unfavorable for weakly rigid components

Engineering Contradiction:
Improveelastic recoveryVSAvoidcompressive strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by varying the cross-sectional geometry of different ribs within the same seal. Specifically, ribs at curved portions of the joint have different dimensions than ribs at straight portions. This allows each rib to be optimized for its local mechanical environment, providing higher elastic recovery where needed without unnecessarily increasing compressive strength across the entire seal, thus resolving the contradiction between reliability and strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes geometric parameters of the sealing ribs to balance elastic recovery and compressive strength. By adjusting rib height, thickness, and cross-sectional area at different locations, the seal achieves optimal performance: ribs with greater height and thinner sections provide elastic recovery, while ribs with appropriate dimensions maintain compressive strength. This parameter optimization resolves the contradiction by showing that both properties can coexist through careful design.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If straight ribs and curved ribs of identical dimensions are used, then manufacturing is simplified, but uneven distribution of contact pressure occurs leading to variations in sealing efficiency

Engineering Contradiction:
Improverib dimensions consistencyVSAvoidsealing efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent implements local quality by specifying that ribs at curved portions of the joint have different cross-sectional dimensions than ribs at straight portions. This acknowledges that curved and straight sections experience different stress distributions and requires tailored rib geometries to achieve uniform contact pressure. While this increases manufacturing complexity slightly, it significantly improves sealing reliability by ensuring homogeneous pressure distribution across the entire joint circumference.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If a seal is designed with uniform rib dimensions, then manufacturing precision is easier to maintain, but the seal cannot compensate for losses of elastic recovery in individual ribs

Engineering Contradiction:
Improverib dimension uniformityVSAvoidelastic recovery compensation
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent resolves this contradiction by applying local quality principles: ribs are designed with different cross-sectional dimensions based on their location. Ribs at curved portions have optimized dimensions for their specific mechanical environment, while ribs at straight portions have different dimensions. This location-specific design allows the seal to compensate for elastic recovery losses in any individual rib while maintaining reasonable manufacturing precision through standardized production methods for each rib type.

Inventive Principle:
Principle #3Local quality

4Strength

If the compressive strength of the seal is increased to prevent leaks under high pressure, then sealing effectiveness is improved, but the contact pressure distribution becomes uneven and some areas may still leak

Engineering Contradiction:
Improvecompressive strengthVSAvoidcontact pressure homogeneity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent addresses this contradiction through local quality by designing ribs with location-specific cross-sectional dimensions. Ribs at curved portions and ribs at straight portions have different geometries optimized for their respective stress conditions. This ensures that compressive strength is appropriately distributed throughout the seal, preventing both overall failure and localized leakage while maintaining homogeneous contact pressure distribution across the joint circumference.

Inventive Principle:
Principle #3Local quality

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 seal achieves efficient and regular sealing by distributing contact pressure uniformly, maintaining effective sealing under deformation and temperature changes, while allowing for easy adjustment of mechanical properties to suit different joint configurations.

Implementation Method 1

a seal, in particular for mounting a weakly rigid component on said engine block, capable of being incorporated between a first surface and a second surface to be sealed, having a good capacity for elastic recovery

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2202431B1Engine block joint, in particular for installing a slightly rigid component on said engine block
Publication Date: 2012.02.29 CARL FREUDENBERG KG
  • EP2202431B1 patent drawingFigure 1
  • EP2202431B1 patent drawingFigure 2
  • EP2202431B1 patent drawingFigure 3~4

AI summary

The joint (10) has a core inclined with respect to flat and parallel surfaces to be sealed, where the core has two contact zones in contact with the respective surfaces. A portion of the core includes an extension (30) at the level of the contact zones, where the extension does not extend on entire portion of the core to locally increase compression resistance and to homogenize contact pressure on the surfaces. An inner end (16) of a section of the core in a transverse plane contacts one of the surfaces and defines an inner contour (Cint) of the joint.