Asymmetric Thread Rolls for Compact Axial Rolling Heads
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Solution Overview
Problem
Existing axial thread rolling heads require significant space for radial movement of thread rolls and actuation mechanisms, leading to processing errors and inaccuracies, especially when machining high-strength materials, due to springing of thread rolls and limited structural support.
Innovation Solution
An axial thread rolling head with asymmetrical thread rolls that are immovably held in the radial direction, featuring a pointed profile with specific flank angles and a non-opening design, which compensates for spring-back and ensures precise symmetrical thread formation without the need for a complex actuation mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thread rolls are allowed to move radially in opening rolling heads, then the thread rolls can be adjusted outwards to prevent engagement with the workpiece, but this requires large working space and complex actuating mechanisms
Solution Approach 1:
The invention extracts and eliminates the opening mechanism from the rolling head design. By making the rolling head non-opening with fixed thread rolls, the complex actuating mechanism and large radial movement space are removed, while thread formation accuracy is maintained through the asymmetric profile design that prevents roll springing.
Solution Approach 2:
Instead of allowing radial movement to prevent engagement, the invention inverts the approach by fixing the rolls radially and using asymmetric profiling to achieve the same protective effect. The asymmetric profile with different leading and trailing flank angles prevents the rolls from springing outwards during engagement, eliminating the need for opening mechanisms.
2Manufacturing precision
If structural support measures are increased to prevent thread roll springing, then manufacturing precision improves, but the device complexity and space requirements increase
Solution Approach 1:
The invention applies asymmetry to the thread roll profile by designing different flank angles: the leading flank angle (25°-35°) is smaller than the trailing flank angle (30°-40°). This asymmetric configuration creates inherent stability that prevents radial springing during the rolling process, achieving high manufacturing precision without complex structural support measures.
Solution Approach 2:
The invention changes the geometric parameters of the thread roll profile, specifically the flank angles. By optimizing the leading and trailing flank angles within specific ranges, the rolls achieve stable engagement without excessive springing, maintaining precision while avoiding complex support structures.
3Area of stationary object
If the axial thread rolling head is designed to be compact with small external dimensions, then space requirements are reduced, but the thread rolls have limited support against springing open
Solution Approach 1:
The asymmetric profile design with different leading and trailing flank angles provides inherent stability to the thread rolls. This prevents radial springing even in compact head designs, maintaining reliability without increasing head size. The asymmetric geometry creates a self-stabilizing effect during the rolling process.
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
Enables precise and reliable production of external threads on workpieces with relatively large diameters using an axial thread rolling head with small external dimensions, reducing space requirements and maintaining high dimensional accuracy even with high-strength materials.
Implementation Method 1
external threads are produced on generally cylindrical workpieces by cold forming
Data Source
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AI summary
The invention relates to an axial thread rolling head, comprising a head part, in which at least three thread rolls are rotatably mounted, wherein the thread rolls among themselves border an insertion section for a workpiece and wherein the thread rolls each have a profile for forming an outer thread on the workpiece, wherein the thread rolls are held non-adjustably in the radial direction in the head part, wherein the profile of the thread rolls is respectively designed asymmetrically such that the thread rolls with their asymmetrical profile form a symmetrical external thread on the workpiece. The invention also relates to a corresponding method.