Damper Thin Wall Portion Elastic Deformation Demolding

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Solution Overview

Problem

Conventional dampers experience torque instability due to curling issues during demolding, which affects the fitting state and performance, and existing manufacturing methods limit design flexibility and lead to tapered shapes.

Innovation Solution

A damper design featuring a housing member with a thin wall portion between the groove and bottom portions, allowing elastic deformation during demolding to prevent curling, and a manufacturing method that molds this thin wall portion to ensure precise fitting and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the outer part is demolded from the core pin before it is completely hardened to shorten molding time, then productivity is improved, but the edge of the outer part curls up causing torque instability

Engineering Contradiction:
Improvemolding timeVSAvoidfitting state stability
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a thin-walled portion specifically at the groove portion of the outer part. This localized thin-walled structure allows the groove area to be more flexible and resistant to curling during premature demolding, while the rest of the outer part maintains its structural integrity. The thin-walled portion is formed by controlling the molding process to create varying wall thickness in a specific location, enabling the outer part to be demolded before complete hardening without causing edge curling.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If a taper enlarging in diameter is used in the forming die to prevent curling, then the fitting state is stabilized, but the molded article becomes tapered limiting design flexibility

Engineering Contradiction:
Improvefitting state stabilityVSAvoiddesign flexibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

Instead of applying a taper to the entire molded article, the patent uses local quality by creating a thin-walled portion only at the groove area. This localized approach prevents curling at the critical fitting interface without imposing a tapered shape on the entire outer part, thereby maintaining design flexibility for other portions of the component.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the wall thickness of the outer part, creating a thin-walled portion at the groove area while maintaining normal wall thickness elsewhere. This segmentation allows the groove region to have different mechanical properties (more flexible, resistant to curling) while the rest of the structure maintains its original design specifications, avoiding the need for a global taper.

Inventive Principle:
Principle #1Segmentation

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 stabilizes the shearing torque by preventing curling and ensuring precise fitting between components, improving the damper's performance and reducing molding time and costs.

Implementation Method 1

a thin wall portion which is thinner than the outer cylinder portion is formed between the groove portion and the bottom portion in the outer cylinder portion

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3260727B1Damper and damper production method
Publication Date: 2020.11.04 NIFCO INC
  • EP3260727B1 patent drawingFigure 1(a)~1(b)
  • EP3260727B1 patent drawingFigure 2
  • EP3260727B1 patent drawingFigure 3(a)~3(b)

AI summary

A damper is formed by a housing member wherein an outer cylinder portion and an inner cylinder portion that are cylindrically formed are concentrically disposed, and respective lower ends are connected to each other at a bottom portion, and at an upper end of the outer cylinder portion, an open end portion is formed, and a groove portion is formed on an inner periphery; and a lid member provided with a rotor inserted from the open end portion, and housed in the housing member, and formed with a projection portion engaging the groove portion. A thin wall portion which is thinner than the outer cylinder portion is formed in a vicinity of a groove portion side in the outer cylinder portion.