Loom Let-off Control for Tension Stability During Temple Switching

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Solution Overview

Problem

The existing loom technology experiences issues with fabric quality and warp insertion faults due to sudden changes in warp tension when the temple position is switched between operating and standby positions during the transition between weave sections of different densities, leading to unstable warp let-off control.

Innovation Solution

A warp let-off control method that adjusts the let-off motor speed by applying tension correction to the basic speed based on detected tension deviations, using an automatic temple position switching mechanism to cancel out tension changes during the displacement of the temple between operating and standby positions, employing different control modes to compensate for changes in warp tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the temple position is switched between operating and standby positions to adapt to different weave sections, then the fabric quality is improved by preventing crimping in high density sections, but the warp tension changes suddenly causing fabric quality reduction and warp insertion faults

Engineering Contradiction:
Improvetemple position switchingVSAvoidwarp tension stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The control device detects the temple position switching in advance and proactively adjusts the let-off motor speed before the temple actually moves. By predicting the upcoming tension change and compensating for it beforehand, the system prevents sudden tension fluctuations rather than reacting to them after they occur, thus maintaining warp tension stability during temple position transitions

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors the temple position and let-off motor speed, using this feedback to dynamically adjust the let-off control. When temple position switching is detected, the system modifies the let-off motor speed based on the actual temple movement state, creating a closed-loop control that maintains stable warp tension despite temple position changes

Inventive Principle:
Principle #23Feedback

2Reliability

If the let-off motor speed is adjusted to compensate for temple position changes, then the warp tension stability is improved, but the control complexity increases

Engineering Contradiction:
Improvewarp tension stabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device automatically detects temple position switching and independently adjusts the let-off motor speed without requiring external intervention or complex manual control. The system serves itself by using its own sensors and processors to monitor temple position and autonomously compensate for tension changes, reducing the need for additional complex control mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control device adjusts the let-off motor speed parameter dynamically based on the temple position switching state. By changing the motor speed parameter in response to detected temple movement, the system simplifies the control approach to a single key parameter adjustment rather than requiring complex multi-parameter control systems

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2392706B1Let-off control method and let-off control device for loom including temple device having automatic temple position switching mechanism
Publication Date: 2016.09.21 TSUDAKOMA KOGYO KK
  • EP2392706B1 patent drawingFigure 1
  • EP2392706B1 patent drawingFigure 2
  • EP2392706B1 patent drawingFigure 3

AI summary

In a warp let-ff control method performed by a let-off device of a loom, the loom used for weaving a fabric (2a) having two or more weave sections with different densities, the loom including the let-off device that controls an amount of warp let-off by performing let-off control in which a let-off motor (5c) is driven in accordance with a detected tension and a target tension, and a temple device (40) including a temple (41) that is displaceable between an operating position and a standby position, the temple device automatically switching a position of the temple between the two positions in accordance with a weft density of one of the weave sections to be woven, the method includes controlling driving of a let-off motor with a control mode during a control period including a period during which the temple is displaced, the control mode adjusting an amount of warp let-off in a direction such that a change in a warp tension due to the displacement of the temple is cancelled out, the control mode being different from a control mode for performing let-off control in a normal operation of the loom after the control period.