Multi-Chamber Tool Mounting for Stiff, Repeatable Clamping

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Solution Overview

Problem

Existing tool mounting assemblies for machine tools lack sufficient stiffness and repeatability for handling high process forces and operating in challenging conditions, with existing clamping systems experiencing instability due to fluid migration in annular chambers.

Innovation Solution

A tool mounting assembly with at least three independently expandable chambers within the mount, allowing for individual pressure adjustment of a flowable material to achieve high stiffness and stability, and an end plate for additional tool retention, preventing separation under high loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single annular chamber is used for clamping, then the structure is simple, but fluid migration causes instability and inadequate stiffness

Engineering Contradiction:
Improvechamber structureVSAvoidclamping stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single annular chamber is divided into multiple independent chambers (at least three) that are radially offset from each other. Each chamber can be pressurized independently, preventing fluid migration and providing stable, controllable clamping forces. This segmentation resolves the contradiction by maintaining structural simplicity while eliminating the instability caused by fluid migration in a single chamber.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If existing clamping systems are used, then the structure is simple, but positional accuracy repeatability is inadequate for high precision requirements

Engineering Contradiction:
Improveclamping system structureVSAvoidtool positioning repeatability
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The clamping system uses dynamically adjustable pressure in each chamber to achieve precise tool positioning. By independently controlling the pressure in each chamber, the system can compensate for variations and achieve micron-level repeatability. This dynamic control resolves the contradiction between simple structure and high precision positioning requirements.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If conventional clamping assemblies are used, then the design is simple, but stiffness is inadequate for handling high process forces

Engineering Contradiction:
Improvemounting assembly designVSAvoidinterface stiffness
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The engagement surface is divided into multiple local contact points, each controlled by a separate chamber. This allows localized adjustment of clamping forces at different positions, optimizing the distribution of process forces and increasing overall interface stiffness. The local quality principle resolves the contradiction by enabling precise force distribution without requiring a fundamentally complex assembly design.

Inventive Principle:
Principle #3Local quality

4Force

If high clamping forces are applied to ensure tool retention, then tool security is improved, but positional accuracy and repeatability deteriorate due to deformation

Engineering Contradiction:
Improveclamping forceVSAvoidtool positioning accuracy
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The clamping force is segmented into multiple independent chambers that can be pressurized individually. This allows the total clamping force to be distributed across multiple contact points, preventing localized deformation that would compromise positional accuracy. The segmentation principle enables high clamping forces to be applied while maintaining precision through balanced force distribution.

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 assembly provides micron-level repeatability and high stiffness, enabling the transmission of large process forces while maintaining tool stability and safety, even under high-speed and high-pressure conditions.

Implementation Method 1

an increase in the pressure within the chamber above a predetermined threshold expands the chamber, which causes the coupled portion of the engagement surface to move in a radial direction

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Data Source

PatentEP3481573B1Tool mounting assemblies and methods of operation thereof
Publication Date: 2023.06.28 FIVES LANDIS
  • EP3481573B1 patent drawingFigure 1~2
  • EP3481573B1 patent drawingFigure 3
  • EP3481573B1 patent drawingFigure 4

AI summary

A tool mounting assembly (4) for coupling a tool (2) to a rotary drive of a machine tool. The assembly comprises a mount (6) having a longitudinal axis (10) and defining an engagement surface (22) for engaging with a tool to be rotated about the longitudinal axis, and at least three independently expandable chambers (20) within the mount for receiving a flowable material. Each chamber is mechanically coupled to a respective portion of the engagement surface, such that an increase in the pressure within the chamber above a predetermined threshold expands the chamber, which causes the coupled portion of the engagement surface to move in a radial direction relative to the longitudinal axis.