Active Tool Vibration Damping With Piezoelectric Inertial Mass

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Solution Overview

Problem

Existing vibration control solutions in mechanical machining are limited by reduced versatility, excessive weight, and inability to be integrated into machines, leading to reduced maneuverability and increased operator fatigue and risk of accidents.

Innovation Solution

A device with a housing shell containing a rigid inertial mass, accelerometers, and piezoelectric actuators that actively damp vibrations by displacing the inertial mass against elastic resistance, providing improved rigidity/weight ratio, modularity, and versatility, while being lightweight and adaptable to various machines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If known vibration control solutions are applied, then vibrations are controlled within a predefined frequency range, but versatility is reduced and ad-hoc design is required for each machine

Engineering Contradiction:
Improvevibration control effectivenessVSAvoidapplicability to various machines
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The device is designed with a universal mounting structure that can be attached to different machine types without ad-hoc design. The housing shell includes a mounting plate with multiple mounting holes that can be positioned at various locations, allowing the same device to be adapted to different machines and frequency ranges through simple repositioning rather than redesign

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The device incorporates adjustable frequency tuning capabilities through variable stiffness elements. The mounting plate can be positioned at different locations and orientations, and the inertial mass can be adjusted, allowing the device to dynamically adapt to different frequency ranges and machine characteristics, transforming a static device into a dynamically adjustable solution

Inventive Principle:
Principle #15Dynamics

2Reliability

If known vibration control solutions are applied, then vibration damping is achieved, but weight becomes excessive compromising maneuverability

Engineering Contradiction:
Improvevibration damping effectivenessVSAvoiddevice weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The device utilizes composite construction with a lightweight housing shell made from materials optimized for strength-to-weight ratio. The inertial mass is precisely sized and shaped to provide the necessary vibration damping effect while minimizing excess weight. The combination of these elements creates a composite structure that achieves effective vibration control without the excessive weight of traditional solutions

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The device allows for adjustment of the inertial mass parameters and mounting configuration to optimize the weight-effectiveness ratio. By changing the mass value, distribution, and mounting position, the device can be tuned to achieve the minimum necessary weight for effective vibration control in different applications, rather than using a fixed heavy design

Inventive Principle:
Principle #35Parameter changes

3Reliability

If known vibration control solutions are applied, then vibration protection is provided, but volume increases and field of application is reduced

Engineering Contradiction:
Improvevibration protectionVSAvoiddevice volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The device features a compact nested structure where the inertial mass is contained within the housing shell, which in turn is mounted on the machine structure. This nested arrangement minimizes the overall volume footprint by efficiently utilizing internal space rather than requiring separate external components, allowing the device to be integrated into confined spaces on various machines

Inventive Principle:
Principle #7Nested doll (Nesting)

4Reliability

If known vibration control solutions are applied, then machine structure is protected from vibrations, but integration into the machine is difficult

Engineering Contradiction:
Improvemachine structure protectionVSAvoidintegration ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The device is segmented into distinct modular components: the housing shell, the inertial mass, the mounting plate, and fastening elements. This segmentation allows each component to be manufactured independently using standard processes, simplifying production and assembly. The mounting plate with pre-drilled holes provides a standardized interface that facilitates easy integration into different machine structures without complex custom fabrication

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 device effectively dampens vibrations across a wide range of frequencies, enhancing machine stability and operator safety with reduced weight and volume, and can be industrialized at competitive costs without substantial machine modifications.

Implementation Method 1

at least one piezoelectric actuator, in electrical connection with said at least one accelerometer and interposed between said at least one mass and said housing shell, and adapted to transform each of said electric voltages into an input applied to said at least one inertial mass and thus into a displacement of said inertial mass

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

at least one accelerometer adapted to generate, when subjected to vibrations, an electric voltage for each of said vibrations

Methodology Applied
Scientific EffectAccelerometer sensing: Accelerometer

Implementation Method 3

said component parts housed inside said housing shell comprise at least one flexible member interposed between said housing shell and said at least one inertial mass, so that each displacement of said inertial mass generated by said at least one piezoelectric actuator occurs against the elastic resistance exerted by said at least one flexible member

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3587030B1Device for actively controlling vibrations in a machine tool
Publication Date: 2022.08.31 UNIV DEGLI STUDI DI BRESCIA
  • EP3587030B1 patent drawingFigure 1
  • EP3587030B1 patent drawingFigure 2
  • EP3587030B1 patent drawingFigure 3

AI summary

A device (100) for actively controlling vibrations adapted to be interposed between the tool (202) of an operating machine (200) and the main structure (201) of said operating machine (200), said device (100) comprising a housing shell (101) in which component parts of said device (100) are housed, adapted to operate synergistically for actively controlling, in particular for reducing, the vibrations generated by said tool (202) during use of said operating machine (200) so that said vibrations are not transmitted to said main structure (201) of said operating machine (200).