Variable Speed Edge-Cutting Device for Corrugated Board

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Solution Overview

Problem

Existing edge-cutting devices in corrugating machines generate excessive defective sheets during order changes due to inadequate control over the time interval between edge cutting operations, leading to increased lengths of blank portions.

Innovation Solution

An edge-cutting device with a control system that calculates the order changing time and variably controls the rotation speed and time interval between first and second edge cutting operations, minimizing the distance between edge cuts and optimizing the length of blank portions based on center-cutting and slitter scorer-setting times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the edge-cutting device performs multi-cut type edge cutting with fixed rotation speed, then the cutting process is simple to control, but the length of blank portions increases excessively during order changes

Engineering Contradiction:
Improvecontrol simplicityVSAvoidlength of defective sheets
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The patent applies dynamics by making the rotation speed of the edge-cutting knife variable rather than fixed. The control device adjusts the rotation speed according to the timing of order changes and the required time interval between first and second edge cutting, allowing the system to adapt its operational parameters dynamically to minimize blank portion length while maintaining operational simplicity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the time interval between first edge cutting and second edge cutting is extended to accommodate order changes, then the cutting quality is maintained, but the length of blank portions increases

Engineering Contradiction:
Improvecutting qualityVSAvoidlength of blank portions
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies parameter changes by adjusting the rotation speed parameter of the edge-cutting knife based on the timing requirements of order changes. The control device calculates the appropriate rotation speed to ensure the time interval between first and second edge cutting meets the minimum requirement for reliable cutting, while minimizing the resulting blank portion length through optimized parameter selection.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the edge-cutting knife rotates at constant speed, then the mechanical control is simple, but the distance between edge cuts cannot be minimized during order changes

Engineering Contradiction:
Improvecontrol mechanism complexityVSAvoiddistance between edge cuts
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The patent applies feedback by implementing a control device that monitors the timing of order changes and adjusts the rotation speed of the edge-cutting knife accordingly. The control device receives information about when order changes occur and when center cutting is completed, then provides feedback control to optimize the rotation speed and minimize the distance between edge cuts while maintaining cutting quality.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3932634B1Edge-cutting device
Publication Date: 2023.04.05 MITSUBISHI HEAVY IND MACHINERY SYST LTD
  • EP3932634B1 patent drawingFigure 1
  • EP3932634B1 patent drawingFigure 2
  • EP3932634B1 patent drawingFigure 3

AI summary

An edge-cutting device (5) performs edge-cutting for cutting away trimmings of a corrugated cardboard sheet toward the front and back when switching between orders is to be performed in a corrugating machine (1). This edge-cutting device (5) has: an edge-cutting knife (51) that is provided so as to project from the outer circumference of a cylinder (51a) having an axis disposed in the width direction of the corrugating machine; and a control device (70) that, when switching between orders is to be performed, controls the edge-cutting device (5) to perform a first edge-cutting process for edge-cutting trimming of an old order at the first rotation of the edge-cutting knife (51) and a second edge-cutting process for edge-cutting trimming of a new order at the second rotation. The control device (70) is provided with a calculation means (72) for calculating the order switching time, and a variable control means (74) for variably controlling the time interval between the first edge-cutting process and the second edge-cutting process, within the order switching time.