Shrink-Fit Tool Provisioning With Spindle Cooling for Accurate Measurement

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Solution Overview

Problem

Existing shrink-fitting and measuring processes on rotary spindles in machine tools result in thermal expansion due to high heat input, leading to reduced measuring accuracy and complexity from using tool chuck changers and separate grippers.

Innovation Solution

A cooling device associated with the rotary spindle, such as an annular cooling element, is used to air-cool the spindle, combined with a gripper that can handle both tool holders and tools, and a system that includes heating, measuring, and balancing stations for automated tool provisioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-speed shrink-fitting and measuring operations are performed on a rotary spindle, then productivity is improved, but thermal expansion of the spindle increases leading to reduced measurement precision

Engineering Contradiction:
Improvenumber of shrink-fitting and measuring operations per unit timeVSAvoidmeasuring accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The harmful heat generated during high-speed operations is extracted from the rotary spindle through a dedicated cooling device. The cooling device includes cooling channels that circulate coolant through the spindle structure, actively removing thermal energy and preventing thermal expansion that would compromise measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the thermal parameters of the rotary spindle by implementing active cooling. The cooling device maintains the spindle temperature within a controlled range despite high-speed operations, thereby preventing thermal expansion and maintaining measurement accuracy while preserving high productivity.

Inventive Principle:
Principle #35Parameter changes

2Extent of automation

If a tool chuck changer and separate tool gripper are used for automated tool handling, then automation extent is improved, but device complexity increases

Engineering Contradiction:
Improveautomated tool holder and tool moving capabilityVSAvoidcomplexity of tool chuck changer and tool gripper system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The invention merges the functions of the tool holder moving device and the tool moving device into a single integrated system. The gripper is designed to handle both the tool holder and the tool simultaneously, eliminating the need for separate tool chuck changers and reducing overall system complexity while maintaining full automation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gripper is designed as a universal device that can handle both tool holders and tools. It features a first gripping element for the tool holder and a second gripping element for the tool, allowing a single device to perform multiple functions that previously required separate specialized components.

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

Enhances measuring accuracy and simplifies the process by reducing thermal expansion, allowing for higher throughput of complete tools with high repeatability and flexibility.

Implementation Method 1

a cooling device associated with the rotary spindle is provided, by means of which the rotary spindle can be air-cooled

Methodology Applied
Scientific EffectAir cooling: Convection

Implementation Method 2

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

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

As the tool holder cools, possibly with the aid of a cooling device, it shrinks and clamps the tool securely and reliably on all sides

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP3791998B1Device for in particular automated provision of a complete tool
Publication Date: 2026.03.18 FRANZ HAIMER MASCHINENBAU KG
  • EP3791998B1 patent drawingFigure 1
  • EP3791998B1 patent drawingFigure 2~3
  • EP3791998B1 patent drawingFigure 4~5

AI summary

The invention relates to a device for the, in particular automated, provision of a complete tool (3) consisting of a tool holder (5) and a tool (7), in particular a drilling and/or milling tool, with a rotary spindle (45) that can be driven by a drive unit, wherein the rotary spindle (45) has a holding device (47) for holding a tool holder (5), wherein a measuring device (49), in particular optical, for measuring a complete tool (3) held on the rotary spindle (45) and a heating device (55) for heating a shrink-fit chuck (79) of a tool holder (5) held on the rotary spindle (45) are arranged in the area of ​​the rotary spindle (45). According to the invention, a cooling device (63), in particular associated with the rotary spindle, is provided by means of which the rotary spindle (45) and/or a complete tool (3) held on the rotary spindle (45) can be cooled.