Strip Feed Roller Torque Control for Precise Pilot Pin Positioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing machine tools that process strips of material require complex and expensive feed devices for precise control, which are maintenance-intensive due to the need for intermediate ventilation of feed rollers to achieve small tolerances.

Innovation Solution

A method where the material strip is permanently clamped between feed rollers, with controlled holding torque adjustments and the use of servo motors to precisely position the strip without intermediate ventilation, allowing for high-precision feeding by synchronizing the movement profiles of the feed rollers and press ram.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If intermediate release of feed rollers is used to achieve precise strip positioning, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvestrip positioning precisionVSAvoidfeed device complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the holding torque of the feed rollers during the feeding cycle. The holding torque is reduced or removed temporarily to allow pilot pin insertion and strip repositioning, then restored to maintain strip position. This torque parameter modulation enables precise positioning without complex mechanical release mechanisms, resolving the contradiction between positioning precision and device complexity.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If intermediate release of feed rollers is used to insert pilot pins, then manufacturing precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvestrip positioning precisionVSAvoidfeed device operation
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The feed rollers are equipped with servomotors that automatically adjust the holding torque according to the process phase. During pilot pin insertion, the system self-adjusts to reduce or remove holding torque without manual intervention, then automatically restores it. This automated self-adjustment eliminates the need for manual operation changes while maintaining precise positioning, resolving the contradiction between precision and ease of operation.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If holding torque is temporarily removed for pilot pin retraction, then ease of operation is improved, but reliability deteriorates due to potential strip movement

Engineering Contradiction:
Improvepilot pin retractionVSAvoidstrip position stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The holding torque is periodically adjusted according to the process phase: maintained during feeding, reduced/removed during pilot pin insertion and retraction, then restored. This periodic torque modulation is precisely timed and controlled, ensuring the strip remains stable when torque is restored while allowing smooth pilot pin retraction when torque is reduced, resolving the contradiction between ease of operation and reliability.

Inventive Principle:
Principle #19Periodic action

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 enables high-precision belt feed without complex intermediate ventilation mechanisms, reducing maintenance and operational costs while maintaining precise alignment and positioning of the material strip.

Implementation Method 1

The feed rollers are driven by one or more servomotors, with the servomotor(s) and thus the feed rollers driven by them being controlled by a controller per feed interval according to a predefined target movement and standstill profile

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

The material strip is permanently clamped between at least one pair of feed rollers and advanced intermittently by the intermittent rotation of the feed rollers

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4200092B1Method for supplying a material strip to the working zone of a machine tool
Publication Date: 2024.08.14 BRUDERER AG
  • EP4200092B1 patent drawingFigure 1~1G
  • EP4200092B1 patent drawingFigure 2~2G
  • EP4200092B1 patent drawingFigure 3~3F

AI summary

The invention relates to a method for supplying a material strip to the machining zone of a punching press, wherein the material strip is clamped between a pair of feed rollers and is advanced at intervals by means of the rotation, at intervals, of the feed rollers, and wherein the following steps are carried out after every advance of the material strip and before the next advance of the material strip in a feed pause when the material strip is stationary and clamped between the feed rollers: a) holding the material strip by holding the feed rollers with a particular holding torque; b) temporarily reducing or increasing the holding torque of the feed rollers; c) positioning the material strip with reduced or increased holding torque of the feed rollers by introducing one or more pilot pins into allocated pilot openings in the material strip, wherein the material strip is advanced by the pilot pin or pilot pins and the feed rollers are rotated by the material clamped between them when the material strip is displaced, the reduced holding torque being overcome as necessary; and d) removing the pilot pin or pilot pins from the pilot openings of the material strip. With the method according to the invention, it is possible to achieve an extremely precise strip advance without complex piloting mechanisms.