Open-End Spinning Rotor Piecing Speed Control

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Solution Overview

Problem

The existing open end spinning process experiences delays and irregularities in fiber supply during the piecing process, leading to thin points in the thread due to delayed startup and speed adjustments of the opening roller, which affect yarn uniformity and reproducibility.

Innovation Solution

The method involves driving the opening roller at a piecing speed above its normal operating speed during the piecing process to ensure consistent fiber supply and faster fiber buildup in the spinning rotor, followed by a drawing in accumulation process to compensate for delays, with independent speed control using single motor drives and a control mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the opening roller is driven at normal operating speed during piecing, then energy consumption is reduced, but fiber supply delay occurs causing thin points in the thread

Engineering Contradiction:

Improveyarn uniformityVSAvoidpiecing process time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The opening roller speed is dynamically adjusted during the piecing process. The control mechanism increases the opening roller speed to a piecing speed above normal operating speed during piecing operations to ensure timely fiber supply, then reduces it to normal speed during normal spinning operations. This dynamic speed adjustment resolves the contradiction by providing high speed only when needed for piecing while maintaining energy efficiency during normal operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The operating parameters of the opening roller are changed during piecing operations. Specifically, the speed parameter is increased from normal operating speed to a higher piecing speed. This parameter change enables the opening roller to compensate for the delayed startup and speed adjustments inherent in piecing operations, ensuring consistent fiber supply and preventing thin points in the thread.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the opening roller speed is increased during piecing, then fiber throughput is improved, but energy consumption increases

Engineering Contradiction:

Improvefiber throughputVSAvoidopening roller energy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The high-speed operation of the opening roller is limited to specific periodic intervals - only during piecing operations - rather than continuous operation. This periodic high-speed action allows the system to achieve high fiber throughput when necessary while minimizing overall energy consumption during normal spinning operations.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If the opening roller is controlled independently with single motor drive, then speed adjustment flexibility is improved, but device complexity increases

Engineering Contradiction:

Improvespeed control flexibilityVSAvoiddrive system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The drive system is segmented into independent motor drives for the spinning rotor and the opening roller. This segmentation allows each component to be controlled independently, providing flexibility in speed adjustment during piecing operations. The control mechanism can adjust the opening roller speed independently from the spinning rotor speed, enabling optimal performance during piecing without requiring complex coordinated control.

Inventive Principle:

Principle #1Segmentation

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 ensures reproducible fiber supply and improved piecing behavior, maintaining yarn uniformity by increasing fiber throughput and preventing thin points, thus enhancing the quality of the spun yarn.

Implementation Method 1

the opening roller, which continues to run, still releases fibers at this time from the tuft

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

a fiber ring formed in the spinning rotor

Methodology Applied

Scientific EffectCentrifugal Force: Centrifugal Force

Implementation Method 3

a subsequent drawing in accumulation, which is used to reduce a thin point in the thread following the piecing

Methodology Applied

Scientific EffectMechanical Accumulation: Mechanical Accumulator

Data Source

PatentUS7644570B2Method for operating an open-end spinning device

Publication Date: 2010.01.12 SAURER SPINNING SOLUTIONS GMBH & CO KG

AI summary

The invention relates to a method for operating an open-end spinning device (1), comprising a spinning rotor (2) and an opening roller (12), which can be controlled so as to be driven individually independently of one another, wherein after an interruption in the spinning process takes place as a result of the detection of the absence of a thread, a piecing operation is initiated, comprising a piecing process, in which an upper thread passes through a fiber ring formed in the spinning rotor (2) and is connected to the latter, and a subsequent drawing-in accumulating process which serves to reduce a thin point in the thread following the piecer, wherein during the piercing operation, the opening roller (12) is temporarily driven at a piecing speed which is higher than the operating speed of the opening roller (12).