Piezoelectric Power Generator With Shared Magnetic Path

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Solution Overview

Problem

Existing power generation devices using vibration for electric power generation face inefficiencies due to the impact of magnetic forces on the vibrating elements, which can reduce vibrational amplitude and power generation efficiency.

Innovation Solution

The power generation device incorporates a movable element with a magnetic material that moves between two positions, attracting and separating from piezoelectric vibrating elements, causing them to vibrate and generate electric power. This design includes a shared magnetic path to reduce the impact of magnetic forces on the vibrating elements, enhancing power generation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a movable element with magnetic material is used to attract and separate from piezoelectric vibrating elements, then power generation efficiency is improved, but magnetic forces may negatively impact the vibrational amplitude of the vibrating elements

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidvibrational amplitude
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

A magnetic body is introduced as an intermediary component that mediates the magnetic interaction between the movable element and the vibrating elements. The magnetic body is positioned to attract/repel the vibrating elements indirectly through magnetic field interaction, rather than direct contact or strong magnetic attraction. This intermediary approach allows the movable element to control the vibration state while minimizing detrimental magnetic forces on the vibrational amplitude.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the movable element moves between two positions to generate electric power, then energy generation is achieved, but the magnetic attraction may reduce the vibrational amplitude needed for efficient power generation

Engineering Contradiction:
Improveelectric power generationVSAvoidvibrational power
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The system dynamically adjusts the position of the movable element between two positions to control the magnetic field interaction. By carefully designing the movement range and positioning, the system ensures that during the vibration generation phase, the movable element is positioned to minimize magnetic attraction on the vibrating elements, thereby maintaining high vibrational amplitude and power generation efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The movable element performs periodic movement between two positions, creating cyclic magnetic field changes that induce vibration in the piezoelectric elements. The periodic nature of this movement allows the system to generate electric power continuously while maintaining optimal vibrational conditions during each cycle, as the magnetic attraction is only strong during specific phases of the cyclic movement.

Inventive Principle:
Principle #19Periodic 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

The device achieves improved power generation efficiency by minimizing the impact of magnetic forces on the vibrating elements, allowing for consistent and enhanced electric power generation during both movement directions of the movable element.

Implementation Method 1

The power generation unit has a cantilever shape and vibrates to thereby generate electric power

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a movable element with a magnetic material that moves between two positions, attracting and separating from piezoelectric vibrating elements

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP4047808B1Power generation device and input device
Publication Date: 2025.02.19 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4047808B1 patent drawingFigure 1
  • EP4047808B1 patent drawingFigure 2
  • EP4047808B1 patent drawingFigure 3

AI summary

A power generation device includes: a first power generation element that vibrates to generate electric power; a second power generation element that is located lower than the first power generation element to vibrate and thereby generates electric power; and a movable element that attracts the first power generation element downward when the movable element is moving downward, and attracts the second power generation element upward when the movable element is moving upward. The first power generation element vibrates as a result of the downward movement of the movable element, and the second power generation element vibrates as a result of the upward movement of the movable element.