Urethane Rebound Stopper with Asymmetric Protrusions

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Solution Overview

Problem

Conventional urethane-made rebound stoppers in automobile suspensions produce significant hitting noise due to their high hardness and small initial compression amount.

Innovation Solution

The design incorporates approximately cylindrical urethane-made rebound stoppers with protruding portions at each end, arranged in a specific pattern to increase the initial compression amount, and optionally features penetration holes and circular grooves to enhance deformation and reduce noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a urethane-made rebound stopper with high hardness is used, then durability is improved, but hitting noise increases due to small initial compression amount

Engineering Contradiction:
ImprovedurabilityVSAvoidhitting noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The rebound stopper is divided into multiple protruding portions (first, second, third protruding portions) arranged circumferentially, creating space portions between them. This segmentation allows localized deformation in the space portions while maintaining overall structural integrity and durability of the urethane material.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The protruding portions are arranged asymmetrically in the circumferential direction, with each protruding portion having a specific shape and position that creates unequal space portions. This asymmetric arrangement allows for optimized deformation patterns that reduce hitting noise while maintaining durability.

Inventive Principle:
Principle #4Asymmetry

2Strength

If the rebound stopper is made with high hardness material, then strength is improved, but initial compression amount decreases leading to noise

Engineering Contradiction:
ImprovestrengthVSAvoidinitial compression amount
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The invention introduces circumferential dimension variations through protruding portions arranged around the rod. Instead of uniform compression along the axial direction only, the protruding portions create circumferential space portions that enable multi-dimensional deformation, increasing the effective initial compression amount while maintaining material strength.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Different regions of the rebound stopper have different functional qualities: the protruding portions maintain high strength and structural integrity, while the space portions between them are designed to deform and compress. This local differentiation allows the hard urethane material to maintain strength while enabling sufficient initial compression in specific regions.

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 solution effectively reduces hitting noise by increasing the initial compression amount and improving the concentricity of the rebound stopper, while maintaining durability.

Implementation Method 1

the rebound stopper absorbs impact by being compressed as being sandwiched by the rebound sheet and the rod guide

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2600029B1Rebound stopper
Publication Date: 2016.01.27 NOK CORP
  • EP2600029B1 patent drawingFigure 1~2
  • EP2600029B1 patent drawingFigure 3~4
  • EP2600029B1 patent drawingFigure 5

AI summary

The present invention provides a rebound stopper which achieves reduction of hitting noise. In an approximately cylindrical urethane-made rebound stopper 100 which is attached to an outer circumference of a rod 500 arranged reciprocably in a cylinder 600 while being arranged as having one end side faced to a rebound sheet 510 and having the other end side faced to a rod guide 610 and which absorbs impact as being compressed by the rebound sheet 510 and the rod guide 610 as the other end side hitting the rod guide 610 when the rod 500 is moved in a direction in which the rebound sheet 510 approaches to the rod guide 610, a plurality of protruding portions is arranged at each end side while the protruding portions at one end side and the protruding portions at the other end side are arranged at positions as being shifted in the circumferential direction.