Foldable Hinge Structure With Angle-Dependent Torque Control

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Solution Overview

Problem

Conventional hinge structures for foldable electronic devices, such as notebook computers, require users to apply force with both hands to unfold the screen due to insufficient torque support, compromising user experience and increasing device weight when attempting to reduce screen weight.

Innovation Solution

A hinge structure with a shaft sleeve and two rotating shafts that generate different torque outputs based on the angle of the device's bodies, allowing for one-handed unfolding and stable operation by adjusting torque levels as the device transitions from a folded to an unfolded state, using a position-limiting mechanism to manage rotation angles and torque distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the torque generated by the hinge structure is increased to provide sufficient supporting force for the screen, then the screen stability is improved, but it becomes difficult to unfold the screen with one hand and the keyboard base weight increases

Engineering Contradiction:
Improvescreen stabilityVSAvoidunfolding ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The hinge structure dynamically adjusts torque output based on the unfolding angle. When the angle is less than the first angle, the hinge provides first torque that is less than screen gravity, enabling easy one-handed unfolding. When the angle exceeds the first angle, the hinge provides second torque that is greater than screen gravity, ensuring screen stability during use. This dynamic torque adjustment resolves the contradiction between ease of operation and screen stability.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the screen weight is reduced to enable one-handed unfolding, then the unfolding ease is improved, but the screen becomes unstable and may fall during use

Engineering Contradiction:
Improveunfolding easeVSAvoidscreen stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Instead of relying on reduced screen weight, the hinge structure dynamically adjusts its torque output. During unfolding (angle < first angle), the hinge provides lower torque (first torque) that allows easy manipulation. Once unfolded (angle > first angle), the hinge automatically increases torque to (second torque) that exceeds screen gravity, preventing screen fall. This dynamic adjustment maintains screen stability without requiring heavy screens.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the keyboard base weight is increased to provide sufficient support for the screen, then the screen stability is improved, but the overall device weight increases making it inconvenient to carry

Engineering Contradiction:
Improvescreen stabilityVSAvoidkeyboard base weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The hinge structure changes the torque parameter dynamically based on the unfolding angle. By using a position-limiting mechanism with different torque characteristics at different angle ranges, the hinge provides high torque (second torque) when the device is unfolded to ensure screen stability, and low torque (first torque) when folding to enable easy operation. This eliminates the need to increase keyboard base weight while maintaining screen support capability.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the hinge torque is reduced to enable one-handed unfolding, then the unfolding ease is improved, but the screen may fall during use because the hinge cannot provide sufficient support

Engineering Contradiction:
Improveunfolding easeVSAvoidscreen support capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The hinge structure is designed with dynamic torque adjustment capability through a position-limiting mechanism. When the unfolding angle is less than the first angle, the hinge operates in a state providing first torque that facilitates easy one-handed unfolding. When the angle exceeds the first angle, the position-limiting mechanism triggers a torque increase to second torque, which is greater than screen gravity, ensuring the screen remains stable and does not fall during use.

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

Enables one-handed unfolding of foldable electronic devices while maintaining stability in the unfolded state without increasing overall weight, enhancing user convenience and device usability.

Implementation Method 1

the first rotating shaft frictionally fits the shaft sleeve when being rotated relative to the shaft sleeve... first torque is generated due to friction between the first rotating shaft and the shaft sleeve

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the second rotating shaft frictionally fits the shaft sleeve... third torque is generated when the second rotating shaft frictionally fits the shaft sleeve

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4023895B1Hinge structure and foldable electronic device
Publication Date: 2024.10.30 HUAWEI TECH CO LTD
  • EP4023895B1 patent drawingFigure 1~3
  • EP4023895B1 patent drawingFigure 4~6
  • EP4023895B1 patent drawingFigure 7~8

AI summary

A hinge structure and a foldable electronic device are provided. The hinge structure may be used in the foldable electronic device, and include a shaft sleeve (31), a first rotating shaft (32), and a second rotating shaft (33). The shaft sleeve (31) is configured to connect to a first body (10) of the foldable electronic device, and the first rotating shaft (32) is configured to connect to a second body (20) of the foldable electronic device. The first rotating shaft (32) stretches into the shaft sleeve (31) to frictionally fit the shaft sleeve (31), and the second rotating shaft (33) stretches into the shaft sleeve (31) to fit the shaft sleeve (31). In a process in which the foldable electronic device changes from a folded state to an unfolded state, first torque is generated when the first rotating shaft (32) is rotated relative to the shaft sleeve (31). When an included angle between the first body (10) and the second body (20) falls within a range that is less than or equal to a first angle, it is convenient to unfold the foldable electronic device with one hand. When the included angle between the first body (10) and the second body (20) falls within a range that is greater than the first angle and less than a second angle, the hinge structure outputs second torque greater than the first torque, and a screen of the foldable electronic device does not easily fall, to provide convenience for a user.