Tension Generating Roller Position Control for Web Conveyance

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Solution Overview

Problem

Existing web conveying systems face challenges in maintaining consistent tension during web conveyance, especially at the beginning of the process, due to variations in web width, material, and printing conditions, leading to image forming failures and reduced printing quality.

Innovation Solution

A web conveying device with a tension generating mechanism that includes a rotationally driven tension generating roller, sensors for detecting its position and the tension applied, and a control unit that adjusts the roller's position based on web width and previous operational data to maintain optimal tension, using a correction coefficient to set the initial operational position for subsequent conveyances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If printing speed is increased, then productivity is improved, but web conveyance accuracy deteriorates

Engineering Contradiction:

Improveprinting speedVSAvoidweb conveyance accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system performs preliminary actions by detecting web width and ream weight before conveyance begins, pre-calculating the optimal rotational position of the tension generating roller to ensure accurate web conveyance from the start of high-speed printing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from sensors that detect web width and ream weight to dynamically adjust the rotational position of the tension generating roller, maintaining web conveyance accuracy even at increased printing speeds

Inventive Principle:

Principle #23Feedback

2Productivity

If printing speed is increased, then productivity is improved, but web conveyance stability deteriorates

Engineering Contradiction:

Improveprinting speedVSAvoidweb conveyance stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The system performs preliminary actions by detecting web width and ream weight before conveyance begins, pre-calculating the optimal rotational position of the tension generating roller to ensure stable web conveyance from the start of high-speed printing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Inventive Principle:

Principle #23Feedback

3Area of moving object

If web width increases, then area of moving object is improved, but conveyance load fluctuation increases

Engineering Contradiction:

Improveweb widthVSAvoidconveyance load stability

Core Design Contradiction:

Area of moving objectVSStability of the object's composition

Solution Approach 1:

The system applies local quality by detecting the specific web width and ream weight to determine the appropriate rotational position of the tension generating roller, tailoring the tension application to each specific web configuration to prevent load fluctuations

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes parameters by adjusting the rotational position of the tension generating roller based on detected web width and ream weight, optimizing tension application for different web sizes to maintain conveyance stability

Inventive Principle:

Principle #35Parameter changes

4Force

If load applied to web is increased, then force is improved, but web directionality deteriorates

Engineering Contradiction:

Improveconveyance loadVSAvoidweb directionality

Core Design Contradiction:

ForceVSStability of the object's composition

Solution Approach 1:

The system changes parameters by optimizing the rotational position of the tension generating roller based on web width and ream weight detection, applying the appropriate amount of load to maintain both conveyance force and web directionality

Inventive Principle:

Principle #35Parameter changes

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 solution ensures consistent and appropriate tension at the start of web conveyance, reducing image forming failures and improving printing quality by dynamically adjusting the tension generating roller's position and using a correction coefficient to account for variations in web conditions.

Implementation Method 1

a tension generating roller configured to be rotationally driven by a motor about a rotation shaft eccentrically positioned; a pressing roller configured to press the web to the tension generating roller

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9352922B2Web conveying device, printing apparatus, and tension control method

Publication Date: 2016.05.31 RICOH CO LTD

AI summary

A control unit allows a rotational position of a tension generating roller to be changed depending on a width of a web at time of the beginning of conveyance of the web, controls a motor according to a detection signal of a second sensor such that a tension guide maintains its position within a predetermined range during conveyance of the web, causes position data at time of keeping the same value of the position data of the motor for a predetermined period to be stored, calculates an initial operational position of the tension generating roller using the position data and a predetermined correction coefficient, and sets the calculated initial operational position as an initial operational position of the tension generating roller at time of the beginning of next conveyance of web.