Thread Forming Tool With Ogival Lobes for Accurate Profile Measurement

Solution Overview

Problem

Existing methods for producing and measuring ball threads with high accuracy are time-consuming and inadequate, particularly for internal threads, as known stylus instruments struggle to accurately measure the profile of cold forming tabs with polygonally formed thread grooves.

Innovation Solution

A tool with a shaping region featuring radially projecting pressing lobes arranged in a spiral forming curve, where the profile of the lobes is designed to be round arched or ogival, allowing better access for stylus instruments and enhancing measurement accuracy, enabling precise calculation of the thread shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If stylus instruments are used to measure polygonally formed thread grooves, then measurement can be performed, but measurement accuracy is insufficient

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidaccess difficulty

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The pressing lobes are designed with round arched or ogival profiles instead of polygonal shapes. This curvature allows the stylus instrument probe to smoothly access and measure the thread profile without obstruction, significantly improving measurement accuracy while maintaining the cold forming function

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Productivity

If cold forming tabs with polygonal pressing lobes are used, then thread production is efficient, but the profile cannot be measured with sufficient accuracy

Engineering Contradiction:

Improveproduction efficiencyVSAvoidprofile measurement accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The pressing lobes are designed with round arched or ogival profiles instead of polygonal shapes. This curvature allows the stylus instrument probe to smoothly access and measure the thread profile without obstruction, significantly improving measurement accuracy while maintaining the cold forming function

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Manufacturing precision

If high accuracy thread production is pursued, then measurement and rework are needed, but the process becomes time-consuming

Engineering Contradiction:

Improvethread accuracyVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The pressing lobes are pre-formed with the correct round arched or ogival profile during tool manufacturing. This preliminary action ensures that the thread is produced with high accuracy in the first pass, eliminating or reducing the need for subsequent measurement and rework operations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pressing lobes are designed with round arched or ogival profiles instead of polygonal shapes. This curvature allows the stylus instrument probe to smoothly access and measure the thread profile without obstruction, significantly improving measurement accuracy while maintaining the cold forming function

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 tool enables high-accuracy, chipless production and reworking of threads, suitable for scanning with stylus instruments, reducing time expenditure and improving thread wear resistance.

Implementation Method 1

the thread is produced without cutting by means of forming the workpiece; so-called pressing lobes, also known as forming wedges or teeth, use pressure to cause cold deformation of the workpiece

Methodology Applied

Scientific EffectCold deformation: Cold-forming

Implementation Method 2

The advantage of these tools is that the deformation of the surface and the associated hardening increases the hardness of the material in the region of the thread profile, thus creating a thread that is more wear-resistant than with chipping thread generation

Methodology Applied

Scientific EffectHardening:

Data Source

PatentUS11571760B2Tool for chipless production or finishing of a thread, method for producing the tool and method for producing a thread

Publication Date: 2023.02.07 EMUGE WERK RICHARD GLIMPEL GMBH & CO KG FABRIK FUER PRAEZISIONSWERKZEUGE

AI summary

A tool for the chipless production of a thread in a workpiece comprises at least one shaping region which can be rotated about a tool axis (A) for the chipless production or finishing of the thread. The shaping region comprises a plurality of pressing lobes projecting radially outwardly from the tool axis (A) for producing the thread by pressing the pressing lobes into the workpiece surface. The pressing lobes are successively arranged along a forming curve which substantially spirals around the tool axis (A), and the pitch of the forming curve essentially corresponds to the pitch of the thread to be produced or reworked. The forming curve has a helix angle (a), and a profile of at least one pressing lobe is designed in such a way that a thread produced in an axial section containing the tool axis is at least in sections round-arched or ogival.