Shrink-Fit Tool Provisioning With Gripper Handling and Spindle Cooling

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Solution Overview

Problem

High-speed machine tools face challenges with shrink-fitting and measurement processes due to thermal expansion of spindles, leading to reduced measurement accuracy and complexity in tool handling.

Innovation Solution

An apparatus with a spindle-driven rotation system, integrated heating and cooling devices, and a gripper system for automated provisioning of complete tools, including a cooling element to counteract thermal expansion and a gripper for simplified tool handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a spindle is used for holding and rotating the toolholder during shrink-fitting and measurement processes, then automated tool provisioning and measurement are enabled, but thermal expansion of the spindle occurs leading to reduced measurement accuracy

Engineering Contradiction:

Improveautomated tool provisioningVSAvoidmeasurement accuracy

Core Design Contradiction:

Extent of automationVSMeasurement precision

Solution Approach 1:

A gripper system is introduced as an intermediary component to hold and position the toolholder during automated provisioning, replacing the spindle's holding function for this specific task. This separates the automated handling function from the measurement function, allowing the spindle to remain cool and stable during measurement while still enabling automation through the gripper-assisted workflow.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The automated tool provisioning process is segmented into separate stages: initial toolholder positioning by the gripper system, shrink-fitting operations, and final measurement by the measuring device. This segmentation allows different components to optimize their functions independently, with the spindle dedicated to stable measurement rather than handling tasks that generate heat.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple shrink-fitting and measurement processes are performed within a short time, then productivity increases, but heat input into the spindle increases leading to thermal expansion and reduced measurement accuracy

Engineering Contradiction:

Improvethroughput of shrink-fitting and measurement processesVSAvoidmeasurement accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system implements periodic cooling cycles for the spindle between measurement tasks. The measuring device is equipped with cooling capabilities that activate during intervals between measurements, periodically removing heat from the spindle to maintain thermal stability even during high-volume production runs.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The toolholder is pre-positioned and pre-heated by the gripper system and heating device before being mounted on the spindle for measurement. This preliminary preparation reduces the time the spindle needs to be actively heated or adjusted during measurement, minimizing heat input into the spindle while maintaining process throughput.

Inventive Principle:

Principle #10Preliminary action

3Extent of automation

If a tool chuck changer and separate tool gripper are used to move the toolholder and tool, then automated tool provisioning is achieved, but device complexity increases

Engineering Contradiction:

Improveautomated tool provisioningVSAvoidcomplexity of tool handling system

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The gripper system is designed to perform multiple functions: it holds and positions the toolholder during insertion, assists with tool changes, and works coordination with the measuring device. By merging these handling functions into a single integrated gripper system rather than using separate tool chuck changers and grippers, the automation capability is maintained while reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances measurement accuracy and efficiency by reducing thermal expansion and simplifying the provisioning process, allowing for higher throughput and improved repeatability in tool preparation.

Implementation Method 1

the holder is heated, for instance by using an inductive heating device or a heating blower, until the receiving opening has expanded sufficiently for the tool to be inserted

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a cooling device configured for cooling at least one of said spindle or the complete tool held on said spindle

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 3

the holder is heated, for instance by using an inductive heating device or a heating blower

Methodology Applied

Scientific EffectInductive heating: Induction Heating

Data Source

PatentUS11633792B2Apparatus for providing a complete tool

Publication Date: 2023.04.25 FRANZ HAIMER MASCHINENBAU KG

AI summary

An apparatus for provisioning, in particular automatically, a complete tool having a toolholder and a tool, in particular a drilling and/or milling tool. The apparatus has a spindle that can be driven in rotation by a driving device. The spindle has a holding device for holding a toolholder. A measuring device, in particular an optical measuring device, measures a complete tool, held on the spindle. A heating device in the region of the spindle heats a shrink-fit chuck of the toolholder held on the spindle. A cooling device, in particular a cooling device associated with the spindle, enables the spindle and/or the complete tool held on the spindle, to be cooled.