Spindle Length Measuring Rod for Controlled Threaded Insertion

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Solution Overview

Problem

Conventional processing machines are rigid and cannot accurately track the spindle movement during screwing and unscrewing operations, leading to potential damage to the workpiece and machine, especially when dealing with threaded components.

Innovation Solution

A 'soft' measuring system with a movable rod, such as a pneumatic cylinder piston rod, allows for distance measurements from the spindle and enables controlled screwing of screws and threaded inserts by applying a defined force, eliminating the need for separate probes and reducing the risk of collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid spindle drive is used for machining, then manufacturing precision is improved, but the machine cannot safely perform screwing operations with threaded components

Engineering Contradiction:
Improveworkpiece toleranceVSAvoidscrewing operation capability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The system separates the spindle drive function from the measurement function. The spindle maintains its rigid positioning for machining, while a separate measuring rod with flexible contact capability performs the screwing operations. This segmentation allows each component to optimize its specific function without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The measuring rod acts as an intermediary between the rigid spindle system and the workpiece during screwing operations. It provides a compliant interface that can safely contact the workpiece and detect thread engagement without transmitting damaging forces back to the spindle or workpiece.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the spindle is rigidly coupled to the tool, then manufacturing precision is improved, but tracking of spindle movement during screwing becomes difficult

Engineering Contradiction:
Improvespindle positioning accuracyVSAvoidspindle tracking difficulty
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The measuring rod serves as an intermediary measurement element that directly contacts the workpiece during screwing operations. It provides real-time feedback on workpiece position and thread engagement status without requiring direct coupling or tracking of the spindle movement, thereby simplifying the measurement task while preserving spindle positioning accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If a conventional processing machine is used for screwing, then machining capability is maintained, but damage to workpiece and machine occurs due to unforeseeable collisions

Engineering Contradiction:
Improvemachining capabilityVSAvoidcollision damage risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The measuring rod is designed with inherent compliance and controlled contact force capability. Before actual screwing begins, the system can safely establish contact with the workpiece surface and detect proper positioning. The rod's design allows it to absorb unexpected collisions without transmitting damaging forces to the workpiece or machine, providing a cushioning effect against potential harm.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The measuring rod provides continuous feedback on contact force and position during the approach and screwing operations. This feedback mechanism allows the control system to detect proper thread engagement and adjust parameters in real-time, preventing over-tightening or damaging collisions that could occur with rigid spindle-driven screwing.

Inventive Principle:
Principle #23Feedback

4Ease of manufacture

If the hollow bore of the spindle is used only for coolant, then coolant delivery is simple, but the measuring rod cannot be guided

Engineering Contradiction:
Improvecoolant system simplicityVSAvoidmeasuring rod guidance requirement
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The system merges two functions into the single hollow bore structure: coolant delivery and measuring rod guidance. The hollow bore serves dual purposes - transporting coolant to the machining point and providing a guided path for the measuring rod. This eliminates the need for separate guidance mechanisms while maintaining coolant delivery functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hollow bore of the spindle is designed as a multi-functional element. It simultaneously performs coolant delivery and acts as a guide sleeve for the measuring rod. This universal design reduces the overall number of components needed in the system while maintaining both cooling and measurement capabilities.

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

This solution expands the machine's capabilities to safely screw in screws and threaded inserts, ensuring accurate tracking and minimizing damage, while allowing for quick processing times and reproducible measurements.

Implementation Method 1

the rod is designed as a piston rod of a pneumatic cylinder and can be moved with the aid of compressed air

Methodology Applied
Scientific EffectPneumatic pressure: Pressurisation

Data Source

PatentEP3292952B1Processing machine with improved length measuring system
Publication Date: 2021.05.12 FILL GMBH
  • EP3292952B1 patent drawingFigure 1

AI summary

The invention relates to a processing machine (1) with a housing (2), a spindle (4) which is rotatably mounted in the housing (2) and can be driven by a motor (3) and has a hollow bore, as well as a spindle (4) in or on arranged tool holder (5). In addition, the processing machine (1) comprises a rod (10) which can be moved in the hollow bore of the spindle (4) and is connected to a length measuring system (9). The invention also relates to an operating method for such a processing machine (1).