Pneumatic Fender Cord Angle Design for Shape Stability

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Solution Overview

Problem

Pneumatic fenders experience distortion at the boundary between the body and hemispherical portions when expanded, leading to an unstable shape due to differing cord angles in the reinforcing layers, resulting in inadequate expansion of the hemispherical portions compared to the body portion.

Innovation Solution

The pneumatic fender features reinforcing layers with cord angles set between 15° to 45° in both the body and hemispherical portions, allowing the cord angles to increase to a stable static angle when pressurized, enabling greater expansion of the body and hemispherical portions, thus correcting distortion and achieving a more uniform shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the cord angle of the reinforcing layer in the hemispherical portion is set to the same extent as the body portion (54° to 55°) in a neutral state, then the hemispherical portion maintains structural stability, but the hemispherical portion does not expand greatly when pressurized, causing distortion at the boundary between the body portion and hemispherical portions

Engineering Contradiction:
Improvestructural stability of hemispherical portionVSAvoiddistortion at boundary between body portion and hemispherical portions
Core Design Contradiction:
Stability of the object's compositionVSShape

Solution Approach 1:

The patent applies different cord angles to different regions of the fender. The body portion uses a cord angle of 54° to 55° in the neutral state for structural stability, while the hemispherical portion uses a smaller cord angle of 15° to 45° in the neutral state to enable greater expansion. This local differentiation resolves the contradiction by allowing each region to have optimal properties for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a dynamic expansion behavior where the hemispherical portion expands more than the body portion during pressurization. By setting the cord angle in the hemispherical portion to 15° to 45° in the neutral state (smaller than the body portion's 54° to 55°), the structure is designed to undergo greater deformation when pressurized, transforming from a static uniform configuration to a dynamic differential expansion state that prevents boundary distortion.

Inventive Principle:
Principle #15Dynamics

2Volume of moving object

If the cord angle of the reinforcing layer in the body portion is set to from 15° to 45° in a neutral state, then the body portion expands more greatly when pressurized, but the hemispherical portion does not expand proportionally, leading to shape instability

Engineering Contradiction:
Improveexpansion of body portionVSAvoidshape stability of fender
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent applies different cord angles to different regions of the fender. The body portion uses a cord angle of 54° to 55° in the neutral state for structural stability, while the hemispherical portion uses a smaller cord angle of 15° to 45° in the neutral state to enable greater expansion. This local differentiation resolves the contradiction by allowing each region to have optimal properties for its specific function.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the fender is designed to expand greatly during use, then compactness during storage and transportation is improved, but distortion occurs at the boundary between the body portion and hemispherical portions when expanded

Engineering Contradiction:
Improveexpansion ratio during useVSAvoiddistortion at boundary between body portion and hemispherical portions
Core Design Contradiction:
Volume of moving objectVSShape

Solution Approach 1:

The patent applies different cord angles to different regions of the fender. The body portion uses a cord angle of 54° to 55° in the neutral state for structural stability, while the hemispherical portion uses a smaller cord angle of 15° to 45° in the neutral state to enable greater expansion. This local differentiation resolves the contradiction by allowing each region to have optimal properties for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a dynamic expansion behavior where the hemispherical portion expands more than the body portion during pressurization. By setting the cord angle in the hemispherical portion to 15° to 45° in the neutral state (smaller than the body portion's 54° to 55°), the structure is designed to undergo greater deformation when pressurized, transforming from a static uniform configuration to a dynamic differential expansion state that prevents boundary distortion.

Inventive Principle:
Principle #15Dynamics

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 fender expands more significantly during use while maintaining compactness when not in use, reducing storage space and transportation needs, and improves cushioning performance by ensuring a stable and similar overall shape, enhancing prediction accuracy and efficiency of compression elasticity.

Implementation Method 1

the body portion is configured by layering a plurality of reinforcing layers between an inner layer rubber and an outer layer rubber. Each of the plurality of reinforcing layers is a cord layer formed by aligning a number of cords in parallel

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

when the interior of the fender is filled with air to be set to a specified internal pressure

Methodology Applied
Scientific EffectPressure Increase: Pressure Increase

Data Source

PatentEP3653794B1Pneumatic fender
Publication Date: 2022.02.23 THE YOKOHAMA RUBBER CO LTD
  • EP3653794B1 patent drawingFigure 1
  • EP3653794B1 patent drawingFigure 2
  • EP3653794B1 patent drawingFigure 3

AI summary

Provided is a pneumatic fender that can expand more greatly during use than when the pneumatic fender is not in use, such as when stored, transported, or the like, and that can correct distortion at or near a boundary between a body portion and each of hemispherical portions at both ends to expand an overall shape more similarly than in the related art. Reinforcing layers (3) of a body portion (2) and reinforcing layers (5) of a predetermined range (4A) in the longitudinal direction of a fender near a boundary between each hemispherical portion (4) and the body portion (2) are formed by aligning a number of cords (3a, 3b) and cords (5a, 5b) in parallel, and in a neutral state without expansion, the cords (3a, 3b) of the reinforcing layers (3) layered adjacent to each other meet each other and the cords (5a, 5b) of the reinforcing layers (5) layered adjacent to each other meet each other, and cord angles A and B are each set to from 15° to 45° with respect to the longitudinal direction of the fender. When the interior of the fender 1 is filled with air to be set to a specified internal pressure, the cord angles A and B increase to the extent of a static angle, and the body portion (2) and the predetermined range (4A) of each hemispherical portion (4) are greatly enlarged in diameter and expand.