Deep Hole Drill Stiffness Control for 3D Vibration Damping

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Solution Overview

Problem

Current deep hole drilling systems lack effective three-dimensional vibration damping, particularly in the radial direction, which affects machining precision and accuracy, especially as drilling depth increases, and there is a need for localization technology to reduce dependence on imported equipment.

Innovation Solution

A deep hole drilling system with a stiffness control mechanism using MR fluid that includes a vibration detection sensor, a stiffness controller, and a controller to adjust the viscosity of the MR fluid, allowing for independent control of MR fluid storage spaces along the axial direction to damp both axial and radial vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional drilling methods are used for deep holes, then drilling depth can be achieved, but vibration in axial and radial directions increases, reducing machining precision

Engineering Contradiction:
Improvemachining precisionVSAvoidvibration
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameter of the drill system by controlling the viscosity of MR fluid through magnetic field strength adjustment. This dynamically alters the stiffness of the drill, allowing the system to adapt to vibration conditions at different depths, thereby reducing vibration while maintaining machining precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a dynamic vibration damping system where the stiffness of the drill is not fixed but can be adjusted in real-time based on vibration detection. The controller modifies magnetic field strength according to drilling depth and vibration levels, making the drill adaptable to changing conditions throughout the deep hole drilling process.

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If drilling depth increases, then deeper holes can be machined, but vibration damping efficiency of conventional systems decreases

Engineering Contradiction:
Improvedrilling depthVSAvoidvibration damping efficiency
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent utilizes parameter changes in MR fluid viscosity through magnetic field control to maintain vibration damping efficiency at increased drilling depths. By adjusting the magnetic field strength, the system compensates for the reduced damping efficiency that naturally occurs with greater depth, ensuring reliable vibration control throughout the entire drilling process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where vibration sensors detect axial and radial vibrations, and the controller adjusts magnetic field strength accordingly. This closed-loop system ensures that vibration damping efficiency is maintained regardless of drilling depth, as the system continuously adapts to the changing conditions.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If MR fluid storage spaces are divided along axial direction with independent control, then three-dimensional vibration damping improves, but device complexity increases

Engineering Contradiction:
Improvethree-dimensional vibrationVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent divides the MR fluid storage space into multiple segments along the axial direction, each with independent magnetic field control. This segmentation allows different regions of the drill to be optimized for specific vibration directions (axial vs. radial), enabling comprehensive three-dimensional vibration damping through coordinated control of multiple segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs the divided MR fluid storage spaces to serve multiple functions: each segment can independently damp vibrations in different directions, and collectively they provide comprehensive three-dimensional vibration control. This multi-functionality justifies the increased device complexity by delivering superior vibration damping performance.

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

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 system achieves efficient three-dimensional vibration damping regardless of drilling depth, improving machining precision and surface quality by controlling the stiffness of the drill through real-time feedback from acceleration sensors and viscosity adjustments of the MR fluid.

Implementation Method 1

controls the stiffness of the drill by controlling the viscosity of MR fluid

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Implementation Method 2

vibration detection sensor which is provided on the drill body and detects vibration of the drill head

Methodology Applied
Scientific EffectAcceleration sensing: Accelerometer

Data Source

PatentEP4063050A1Deep hole drilling system with three-dimensional vibration damping function using tool stiffness control
Publication Date: 2022.09.28 KOREA INST OF MACHINERY & MATERIALS
  • EP4063050A1 patent drawingFigure 1~2
  • EP4063050A1 patent drawingFigure 3
  • EP4063050A1 patent drawingFigure 4

AI summary

The present disclosure relates to a deep hole drilling system (1000) which processes a deep hole having a depth 10 times to 150 times or more greater than a diameter of the hole, and more particularly to a deep hole drilling system which is equipped with a stiffness control means (D) capable of controlling the stiffness of a drill such that axial and radial vibrations of the drill are reduced, so that the deep hole drilling system has a high machinability, a precise and accurate straightness, and roundness.