Sewing Control Device Dynamic Upper Feed Adjustment
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Solution Overview
Problem
Conventional sewing machines cannot dynamically adjust the upper feed amount during sewing, leading to issues like sewing slippage and damage to the change mechanism, as the feed amount is typically set before sewing and cannot be changed in response to cloth thickness or sewing speed.
Innovation Solution
A sewing control device that includes a control system with a lower feed amount setting motor, an upper feed amount change motor, and sensors to detect sewing speed, cloth thickness, and operation amounts, allowing for real-time adjustment of the upper feed amount during sewing by changing the link ratio and using a phase sensor to differentiate between feed execution and non-execution ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the upper feed amount is changed during sewing, then the sewing precision and adaptability to cloth thickness/speed are improved, but the risk of damaging the change mechanism increases
Solution Approach 1:
The patent implements dynamic adjustment of the upper feed amount during sewing operations. The control unit receives operation amounts from operation units and dynamically changes the upper feed amount based on these inputs, allowing the system to adapt to different cloth types, thicknesses, and sewing speeds while maintaining mechanical reliability through controlled timing of adjustments.
Solution Approach 2:
The system incorporates operation units that provide feedback on desired feed amount changes, and the control unit processes this feedback to adjust the upper feed amount accordingly. This closed-loop feedback mechanism ensures precise control while preventing damage by coordinating changes with the sewing cycle timing.
2Adaptability or versatility
If the upper feed amount is changed during sewing, then the adaptability to different sewing conditions is improved, but the mechanism complexity increases
Solution Approach 1:
The control unit serves multiple functions: it controls the sewing machine's basic operations, processes operation amounts from various operation units, determines timing of feed amount changes, and coordinates with the feed mechanism. This multi-functional design allows adaptability to different sewing conditions without proportionally increasing overall system complexity.
Solution Approach 2:
The control unit acts as an intermediary between the operation units (user input) and the feed mechanism (execution). It receives diverse operation inputs, processes them according to sewing conditions, and translates them into appropriate feed amount adjustments, simplifying the interface between user needs and mechanical execution.
3Adaptability or versatility
If the upper feed amount is changed during sewing, then the response to cloth thickness and sewing speed is improved, but the risk of mechanical stress and damage increases
Solution Approach 1:
The control unit determines the timing of upper feed amount changes in advance based on the sewing cycle and operation inputs. By planning and executing changes at predetermined safe timing points during the sewing cycle, the system responds adaptively to cloth conditions while preventing mechanical stress that would occur with abrupt or poorly-timed adjustments.
4Device complexity
If the feed amount is set before sewing only, then the mechanism simplicity is maintained, but the sewing slippage occurs
Solution Approach 1:
The patent transitions from static feed amount setting (before sewing only) to dynamic feed amount adjustment (during sewing). The control unit continuously monitors operation inputs and adjusts the upper feed amount in real-time based on actual sewing conditions, eliminating sewing slippage while maintaining reasonable system simplicity through integrated control logic.
Data Source
AI summary
A sewing control device includes in a sewing machine having upper feed function a control device which controls feed of an object to be sewn. A lower feed amount setting motor sets a feed amount of a lower feed dog and an upper feed amount change motor changes a feed amount of an upper feed dog. A feed execution range, in which the feed of the object to be sewn is executed by an appropriate feed amount while the object to be sewn is sandwiched between the lower feed dog and the upper feed dog, and a feed non-execution range, in which the feed of the object to be sewn is not executed in a state in which the feed dogs do not act on the object to be sewn, are present. The feed amount of the upper feed dog can be changed only in the feed non-execution range during sewing.