Foldable Hinge Damping Mechanism for Smooth Rotation

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Solution Overview

Problem

Foldable electronic devices experience poor hand feeling and a short service life due to the poor smoothness of rotation in hinges, which are exacerbated by excessive stress during form switching.

Innovation Solution

A damping mechanism is introduced with a damping fluid cavity and a movable blocking member, where a damping fluid circulation port controls the flow speed of damping fluid, providing a damping force to ensure smooth movement and prevent structural impact during form switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a hinge is provided in the foldable electronic device to enable form switching, then the device can achieve folded and unfolded forms, but the hand feeling is poor and the service life is short due to poor smoothness of rotation

Engineering Contradiction:
Improvehand feelingVSAvoidservice life
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a damping mechanism that utilizes hydraulic principles by filling damping fluid (oil) into a damping fluid cavity. The damping fluid flows through damping fluid circulation ports during hinge rotation, creating resistance that smooths the motion. This hydraulic approach transforms the rough mechanical rotation into smooth controlled movement, directly improving hand feeling while reducing impact on structural components to extend service life.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of manufacture

If the hinge structure is simplified for ease of manufacture, then the device can be produced more easily, but the smoothness of rotation deteriorates leading to poor hand feeling

Engineering Contradiction:
Improveease of manufactureVSAvoidsmoothness of rotation
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The damping mechanism is nested within the existing hinge structure. The damping fluid cavity is formed by enclosing the movable blocking member in the chamber, and the damping fluid circulation ports are integrated into the chamber and/or movable blocking member. This nested design allows the damping function to be incorporated without significantly complicating the overall hinge structure, maintaining ease of manufacture while achieving smooth rotation.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If the damping force is increased to improve hand feeling, then the smoothness of movement is improved, but excessive stress may impact the structure of the foldable electronic device

Engineering Contradiction:
Improvesmoothness of movementVSAvoidstructural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent employs parameter changes by adjusting the viscosity of the damping fluid and modifying the size and number of damping fluid circulation ports. These parameter adjustments allow fine-tuning of the damping force to achieve optimal smoothness of movement. The damping force is controlled to be sufficient for smoothing rotation but not excessive to cause structural damage, thus protecting the integrity of the foldable electronic device.

Inventive Principle:
Principle #35Parameter changes

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 damping mechanism improves the hand feeling and extends the service life of foldable electronic devices by ensuring smooth form transitions and protecting the device structure from excessive stress.

Implementation Method 1

the damping fluid circulation port can limit the flow speed of the damping fluid, thereby providing a damping force to the movement of the power assembly

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP4174270B1Foldable electronic device comprising a hinge with a damping mechanism
Publication Date: 2026.02.11 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4174270B1 patent drawingFigure 1
  • EP4174270B1 patent drawingFigure 2
  • EP4174270B1 patent drawingFigure 3

AI summary

The present invention relates to a damping mechanism (100), a hinge (900) and a foldable electronic device (1000). The damping mechanism (100) includes a chamber (10), a movable blocking member (20) and a power assembly (30). At least part of the movable blocking member (20) is in the chamber (10) and cooperates with an inner wall face of the chamber (10) to closes a damping fluid cavity (110); at least one of the chamber (10) and the movable blocking member (20) defines a damping fluid circulation port (11) in communication with the damping fluid cavity (110); and the power assembly (30) is abutted against the movable blocking member (20), and configured to drive the movable blocking member (20) to move relative to the chamber (10) to change a volume of the damping fluid cavity (110).