Rotational Sheet Metal Forming With Inner-Region Clamping Concentricity

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Solution Overview

Problem

Existing methods for producing rotationally symmetrical bodies, such as pressure accumulator housings, face challenges in achieving precise concentricity due to the need for complex clamping tools that can cause unintentional deformation, making them unsuitable for critical applications like automatic transmission components.

Innovation Solution

A method where the sheet metal blank is clamped only in its radial inner region between an inner mandrel and pre-setters, eliminating the need for a rotating clamping tool and ensuring perfect concentricity by forming the hub-shaped projection after the cup-shaped preform, using a single setup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a circumferential clamping tool is used to hold the peripheral edge during hub formation, then the sheet metal blank can be securely held, but the clamping tool causes unintentional deformation of the bent peripheral edge and prevents perfect concentricity

Engineering Contradiction:
Improvesecure holding of sheet metal blankVSAvoidconcentricity of peripheral edge
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention removes the circumferential clamping tool entirely from the process. Instead of clamping the peripheral edge, the sheet metal blank is held only in the radial inner region between the inner mandrel and pre-setter, eliminating the source of deformation and enabling perfect concentricity while maintaining secure holding through the pre-setter arrangement

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention inverts the conventional clamping approach by not clamping the outer peripheral edge at all. Instead, the holding action is applied only to the radial inner region, reversing the typical clamping location and methodology to achieve both secure holding and perfect concentricity

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If the hub is formed first followed by the cup-shaped region, then the production sequence is established, but material in the hub region will crack

Engineering Contradiction:
Improveproduction sequenceVSAvoidintegrity of hub region
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The invention applies preliminary action by forming the cup-shaped region first to create a stable geometric base with proper material distribution, and only then forming the hub projection. This sequence prevents material cracking by ensuring the underlying structure is properly prepared before adding the hub feature

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a rotating clamping tool is used to hold the peripheral edge, then the sheet metal blank can be secured during forming, but the process complexity increases and unwanted deformation occurs

Engineering Contradiction:
Improvesecuring of sheet metal blankVSAvoidclamping tool mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the rotating clamping tool mechanism entirely from the system. The sheet metal blank is secured through a simpler arrangement using only the pre-setter and inner mandrel, eliminating mechanical complexity while maintaining reliable securing during the forming process

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach simplifies the production process, ensures precise concentricity, and eliminates unwanted deformation, making it suitable for components requiring exact concentricity without the need for additional machining.

Implementation Method 1

the sheet metal blank is clamped in the axial direction only in its radial inner region between the inner mandrel and at least one pre-setter

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

in a first pressing process the sheet metal blank is formed into a cup-shaped preform

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 3

the central pre-setter is moved axially in the direction of the inner mandrel in order to clamp the sheet metal blank in its radial inner region against the inner mandrel

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 4

the outer pre-setter is moved axially outwards away from the inner mandrel

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 5

subsequently the hub-shaped projection is formed around the central pre-setter

Methodology Applied
Scientific EffectPlasticity: Plasticity

Data Source

PatentEP3504014B1Method for the chipless production of a rotationally symmetrical body from a circular sheet metal blank
Publication Date: 2025.08.13 WINKELMANN POWERTRAIN COMPONENTS GMBH & CO KG
  • EP3504014B1 patent drawingFigure 1~2
  • EP3504014B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for the chipless production of a rotationally symmetrical body (17) from a circular sheet metal blank. The circular sheet metal blank (8) is shaped into a pot-shaped body (10) by pressing or pressure rolling about an inner mandrel (2), and a hub-shaped protrusion (16) which protrudes outwards from the base of the pot-shaped body (10) is molded on the body by pressing about a central projection (3). The aim of the invention is to improve the method, in particular simplify the production process and ensure a flawless concentricity of the shaped regions. This is achieved in that the circular sheet metal blank (8) is clamped only in the radial inner region of the blank in the axial direction between the inner mandrel (2) and at least one projection (3) during the entire shaping process.