Forming Machine Stroke Timing for Wobble and Tilt Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Elastically mounted forming machines experience wobbling and tilting movements due to inertial forces and moments of inertia, leading to increased mechanical stress and non-compliance with dimensional tolerances, which existing compensation methods attempt to address with increased equipment expenditure.

Innovation Solution

A method that records and adjusts kinematic variables of the forming machine's rigid body movement to counteract inertial forces and moments of inertia by synchronizing the initiation of the working stroke with the instantaneous phase position of these variables, using sensors to detect and control the movement, thereby reducing the amplitude of wobbling or tilting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If compensation devices with movable mass parts are attached to the forming machine, then the rigid body movement and vibrations are reduced, but the device complexity and equipment expenditure increase significantly

Engineering Contradiction:
Improverigid body movement stabilityVSAvoidequipment expenditure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The forming machine uses its own drive system to generate counteracting inertial forces during normal operation, rather than requiring separate compensation devices. The control unit coordinates the drive and ram device to automatically compensate for vibrations and rigid body movements during forming operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the operational parameters of the drive system, specifically timing the initiation of the working stroke to specific phases of the drive cycle and adjusting the drive speed, to generate inertial forces that counteract unwanted movements without adding physical compensation mass.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the initiation time of the working stroke is precisely synchronized with the phase position of kinematic variables, then the inertial forces counteract the rigid body movement and reduce vibrations, but the control complexity increases

Engineering Contradiction:
Improvevibration reductionVSAvoidcontrol complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The control unit continuously monitors the phase position of the drive and adjusts the initiation timing of the working stroke based on real-time kinematic variables, creating a closed-loop control system that automatically optimizes vibration compensation during operation.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If additional sensors and control systems are installed to detect and counteract rigid body movement, then the manufacturing precision improves, but the device complexity and cost increase

Engineering Contradiction:
Improvedimensional tolerancesVSAvoidsensor and control equipment
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The forming machine utilizes its existing drive system components and operational parameters to achieve vibration compensation and improved precision, rather than requiring additional external sensors and control equipment. The drive system itself generates the counteracting forces needed for precision forming.

Inventive Principle:
Principle #25Self-service

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 reduces the deflection of the forming machine, allowing for faster cycle sequences and increased service life of bearings, without the need for significant additional equipment, enabling more precise and efficient operation.

Implementation Method 1

an elastically mounted forming machine (1) with respect to a supporting foundation (9)

Methodology Applied
Scientific EffectVibration isolation: Damping

Data Source

PatentEP4188686B1Method for operating an elastically mounted forming machine, in particular a press
Publication Date: 2024.01.31 LISEGA SE
  • EP4188686B1 patent drawingFigure 1~2
  • EP4188686B1 patent drawingFigure 3
  • EP4188686B1 patent drawingFigure 4a

AI summary

The invention relates to a method for operating an elastically mounted forming machine which is path-bound or force-dependent, in which method a working stroke of a ram device operatively connected to the drive is initiated by means of a drive, and a predefined forming process is carried out on a workpiece by moving the ram device during said working stroke, in particular due to the interaction of an upper tool located on the ram device with a lower tool located on a tool table, wherein the inertial forces and/or moments of inertia occurring during operation owing to the initiation of the working stroke and/or owing to an imbalance in the drive are at least partially compensated. The method according to the invention is characterised in that at least one kinematic variable (s(t),v(t),a(t)) of a rigid body motion of the elastically mounted forming machine is detected during the operation thereof, wherein the time at which the working stroke is initiated is adapted to an instantaneous phase position of the at least one kinematic variable (s(t),v(t),a(t)) of the rigid body motion in order to generate inertial forces and/or moments of inertia so as to counteract the rigid body motion of the forming machine.