Air Damper Piston Recess Air Pocket Elimination

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Solution Overview

Problem

Conventional air dampers with pistons made of synthetic resin suffer from a 'damper inactive zone' due to air pocket formation, leading to incomplete damping effect and potential sink or deformation issues during molding.

Innovation Solution

The air damper design incorporates a cylindrical piston with a recess portion and a protruding arc or circular rib on the cylinder bottom, which reduces air accumulation and eliminates the idling distance by ensuring the piston maintains contact, thus maintaining a consistent damping effect throughout its stroke.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a recess portion is provided on the piston end surface to prevent sink during molding, then sink or deformation is prevented, but air pocket is formed in the recess portion causing damper inactive zone

Engineering Contradiction:

Improvepiston shape accuracyVSAvoiddamping function continuity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention extracts the harmful air pocket from the recess portion by introducing a protruding portion from the cylinder bottom that physically removes the air trapped during piston movement, thereby eliminating the damper inactive zone while preserving the recess portion needed for preventing sink during molding

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The protruding portion acts as an intermediary element between the cylinder bottom and the recess portion, facilitating the removal of air pockets and enabling continuous damping function without compromising the piston's structural integrity during molding

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the piston is formed in a solid shape without recess portion, then air pocket formation is prevented, but sink or deformation occurs during molding

Engineering Contradiction:

Improvedamping function continuityVSAvoidpiston shape accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention segments the piston structure by providing a recess portion in the piston body, which is necessary for preventing sink during molding, while simultaneously introducing a protruding portion in the cylinder bottom to segment and remove the harmful air pocket, thus achieving both objectives

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If air pocket expands in the recess portion when cover opens, then air resistance is not generated in the initial phase, but damper inactive zone is created

Engineering Contradiction:

Improvecover opening smoothnessVSAvoiddamping response timing

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The protruding portion is pre-positioned in the cylinder bottom to act on the air pocket in the recess portion before the cover opens and before the piston moves, preventing air accumulation and eliminating the damper inactive zone, thereby ensuring immediate damping response from the start of piston movement

Inventive Principle:

Principle #10Preliminary action

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

This design ensures a consistent and effective damping action throughout the piston's stroke, preventing sudden openings and enhancing the quality of operation while preventing sink or deformation, and increasing the structural strength of the piston.

Implementation Method 1

air moves between the two chambers via the orifice. When the cover opens and the O-ring moves, the groove is closed and air moves between the two chambers via the orifice. Accordingly, it is possible to provide an air damper in which damper effect is obtained through the orifice when the cover opens

Methodology Applied

Scientific EffectAir flow resistance: Drag

Implementation Method 2

When the cover is closed and the O-ring moves, air moves between the two chambers via the groove. Accordingly, it is possible to provide an air damper in which damper effect is obtained through the orifice when the cover opens, and resistance becomes small due to air passing through the groove when the cover is closed

Methodology Applied

Scientific EffectAir flow:

Implementation Method 3

A protruding portion is provided on the bottom of the cylinder, and protrudes into the recess portion when the piston moves into the cylinder to a maximum extent... air is not accumulated in the recess portion to a large extent. Accordingly, it is possible to reduce an idling distance (interval in which damper effect is not obtained)

Methodology Applied

Scientific EffectAir displacement:

Data Source

PatentUS7353922B2Air damper

Publication Date: 2008.04.08 NIFCO INC

AI summary

An air damper includes a cylinder having a bottom, a piston received inside the cylinder to move freely back and forth coaxially, and an orifice provided in the piston. The piston is formed of a synthetic resin, and has a piston rod extending toward a side of the cylinder opposite to the bottom, and a recess portion provided on a portion facing the bottom in order to prevent sink or the like during molding of the piston. A protruding portion is provided on the bottom of the cylinder to protrude into the recess portion when the piston is fully moved into the cylinder.