Loom Driving Control Device Reduces Main-Shaft Load

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Solution Overview

Problem

Looms face excessive load on the main-shaft driving device during startup, leading to potential defects in fabric weaving and premature device damage due to high rotational speed requirements and short start-up times, which can result in weaving bars or light filling bars if weft insertion is not adequately performed.

Innovation Solution

A driving control method for looms that sets a start-up rotational speed lower than the set rotational speed, at least 25% of it, and gradually increases to the set speed through intermediate speeds, accompanied by weft insertion during startup, to reduce load on the main-shaft driving device and ensure sufficient beating force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotational speed of the main shaft is raised to the set rotational speed in a short start-up time, then the productivity is improved, but the load applied to the main-shaft driving device becomes excessive

Engineering Contradiction:
Improvestart-up timeVSAvoidload on main-shaft driving device
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The patent applies dynamics by making the rotational speed profile adjustable and adaptable to different weaving conditions. The control device allows selection between different acceleration patterns (first pattern with higher acceleration, second pattern with lower acceleration), enabling the system to dynamically adjust its behavior based on real-time conditions rather than following a fixed speed curve.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of rotational speed acceleration profile from a fixed pattern to a selectable pattern. By allowing the operator to choose between different acceleration patterns based on weaving conditions, the system can optimize between start-up time and load application, effectively managing the contradiction through parameter variation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the set rotational speed is high and the start-up time is short, then the productivity is improved, but an excessive load may be applied to the main-shaft driving device

Engineering Contradiction:
Improvestart-up timeVSAvoidmain-shaft driving device
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the acceleration pattern based on weaving conditions. When high set rotational speed is required, the operator can select the second acceleration pattern which provides lower acceleration, thereby protecting the main-shaft driving device from excessive load while still achieving the desired high speed operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent allows changing the acceleration parameter from the first pattern to the second pattern based on the set rotational speed and weaving conditions. This parameter change enables the system to maintain reliability by reducing acceleration stress when operating at high speeds.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the number of frames used in a shedding device is large or a large force is required for driving heald frames, then the manufacturing precision is maintained, but the load on the main-shaft driving device at start-up is large

Engineering Contradiction:
Improveweaving qualityVSAvoidload on main-shaft driving device
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The patent applies dynamics by allowing the acceleration pattern to be adjusted according to the specific weaving configuration. When large numbers of frames or high forces are required, the second acceleration pattern can be selected to reduce start-up load, while still achieving the required weaving precision once operational speed is reached.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system allows parameter change of the acceleration profile to match the mechanical demands of the shedding device. For configurations requiring large forces, the lower acceleration second pattern reduces the peak load during start-up while maintaining the ability to achieve precise weaving at operating speed.

Inventive Principle:
Principle #35Parameter changes

4Force

If the rotational speed of the main shaft is linearly increased in a long start-up time, then the load on the main-shaft driving device is reduced, but a weaving bar may occur in the fabric

Engineering Contradiction:
Improveload on main-shaft driving deviceVSAvoidfabric quality
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by allowing dynamic selection between acceleration patterns. The first acceleration pattern provides faster acceleration that prevents weaving bars by ensuring sufficient beating force, while the second pattern provides lower acceleration that reduces load. The operator can select the appropriate pattern based on the specific weaving conditions and fabric requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the acceleration parameter to match the specific weaving conditions. When there is a risk of weaving bars, the first acceleration pattern is selected to ensure sufficient beating force. When load reduction is the priority and fabric quality is less sensitive, the second pattern is used.

Inventive Principle:
Principle #35Parameter changes

5Force

If the rotational speed of the main shaft is low during start-up, then the load on the main-shaft driving device is reduced, but the beating force is insufficient and light filling bars may occur

Engineering Contradiction:
Improveload on main-shaft driving deviceVSAvoidfabric quality
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by allowing the acceleration pattern to be adjusted based on the specific weaving conditions. When sufficient beating force is critical to prevent light filling bars, the first acceleration pattern is selected. When load reduction is the priority and the fabric is less sensitive to beating force variations, the second pattern is used.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the acceleration parameter to balance load reduction with sufficient beating force. The first acceleration pattern provides higher acceleration that ensures adequate beating force for sensitive fabrics, while the second pattern provides lower acceleration for less sensitive applications.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3530788B1Driving control method of loom and driving control device of loom
Publication Date: 2020.12.30 TSUDAKOMA KOGYO KK
  • EP3530788B1 patent drawingFigure 1
  • EP3530788B1 patent drawingFigure 2
  • EP3530788B1 patent drawingFigure 3

AI summary

A start-up rotational speed that is less than or equal to a rotational speed that is determined by considering a load of the main-shaft driving device, and that is set so as to be greater than or equal to 25% of the set rotational speed is previously set; and a start-up of a loom is performed while being accompanied by a weft insertion in a start-up period for one or more cycles of the loom, and control of the driving motor from when the start-up is started is performed in accordance with the start-up rotational speed, and, when and after the rotational speed of the main shaft has reached the start-up rotational speed, control of the driving of the driving motor is performed in accordance with a predetermined rotational-speed increase mode.