Warp Beam Replacement Threading in Warp Knitting Machines
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Solution Overview
Problem
The existing methods for changing warp beams in warp knitting machines are cumbersome and time-consuming, often resulting in downtimes, damage to knitting tools, and inconsistent thread connections that can impede production due to manual thread handling and unfavorable connection methods.
Innovation Solution
A method where old warp threads are connected to new warp threads using a device, with the warp beam set in rotation by a motor-driven warp beam drive, allowing the old threads to pull the new threads through guide needles, synchronized with the fabric take-off process to ensure smooth thread delivery and minimize stress on the threads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual thread handling and connection methods are used for warp beam replacement, then the process can be completed with simple equipment, but the replacement becomes cumbersome and time-consuming
Solution Approach 1:
The fabric take-off device automatically performs the thread drawing-in function during normal operation, eliminating the need for separate manual drawing-in operations. The system uses its own existing motion to serve the additional function of thread replacement, making the process self-service and significantly reducing downtime.
Solution Approach 2:
The connection between old and new warp threads is established before the fabric take-off begins. By preparing the thread connection in advance and then utilizing the predetermined motion of the fabric take-off device, the system performs the drawing-in action preliminarily planned, avoiding time-consuming manual operations during the replacement process.
2Extent of automation
If manual drawing-in of warp threads is performed, then no additional automation equipment is needed, but the process becomes cumbersome and requires significant personnel involvement
Solution Approach 1:
The fabric take-off device, which normally serves to remove finished fabric from the knitting machine, is made multi-functional by also enabling it to perform the thread drawing-in function during warp beam replacement. This universal approach automates the process without requiring separate dedicated equipment, thus increasing automation while controlling complexity.
Solution Approach 2:
The existing fabric take-off device performs the additional function of drawing in new warp threads, making the system self-sufficient. No external drawing-in mechanism or additional automation equipment is required - the system uses its own operational capacity to accomplish the thread replacement task.
3Reliability
If traditional connection methods are used to join old and new warp threads, then the connection can be made with simple tools, but the connection point creates unfavorable changes in thread properties that can impede passage through guide needles
Solution Approach 1:
The harmful connection point is extracted or removed from the thread path. Instead of allowing a bulky knotted connection to pass through the guide needles, the system cuts the threads at the connection point and uses the fabric take-off motion to draw the new threads through, effectively taking out the problematic connection zone from the critical passage path.
Solution Approach 2:
The fabric take-off device acts as an intermediary mechanism that facilitates the passage of new warp threads through guide needles without requiring the problematic knotted connection to pass through. The fabric take-off motion mediates the thread transition, allowing clean thread ends to be drawn through rather than forcing a bulky connection point through the narrow eyelets.
4Speed
If the warp beam is not set in rotation during thread drawing-in, then the thread feeding process is simpler, but the old warp threads cannot effectively pull the new warp threads through the eyelets
Solution Approach 1:
The warp beam rotation is continuously maintained during the thread drawing-in process, ensuring uninterrupted thread supply. This continuous rotation works in conjunction with the continuous fabric take-off motion to create a synchronized, continuous useful action that efficiently feeds new threads through the guide needles without interruption or manual intervention.
Solution Approach 2:
The system establishes a feedback relationship between warp beam rotation and fabric take-off motion. The rotation speed and take-off speed are coordinated so that the thread feeding rate matches the drawing-in rate, creating a self-regulating system where the motion of one component feedback-controls the other to maintain optimal thread tension and feeding.
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 method significantly reduces downtime, personnel requirements, and yarn consumption while ensuring a low error rate in thread drawing, enabling rapid and reliable thread changes with improved thread compatibility and reduced risk of tool damage.
Implementation Method 1
the old warp threads pull the interchangeable warp threads through the eyelets of the guide needles
Implementation Method 2
setting the warp beam in rotation by means of a warp beam drive of the warp knitting machine, so that the alternating warp threads are actively released by the warp beam
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method for threading after changing the warp beam in a warp knitting machine (1), comprising the steps of: connecting old warp threads, which are guided through eyelets (9) of punching needles attached to a laying bar of the warp knitting machine (1) and form a knitted fabric drawn into a fabric take-off device (3) of the warp knitting machine (1), with replacement warp threads belonging to a warp beam newly exchanged in the warp knitting machine (1); threading the replacement warp threads by having the fabric take-off device (3) pull off the knitted fabric, so that the old warp threads pull the replacement warp threads through the eyelets (9) of the punching needles (8); and, during the threading of the replacement warp threads, setting the warp beam into rotation by means of a warp beam drive of the warp knitting machine (1), so that the replacement warp threads are actively released through the warp beam.The invention further relates to a warp knitting machine (1) with a function for yarn insertion after the warp beam change, with a fabric take-off device (3), with a warp beam, with a warp beam drive coupled to the warp beam and with a control device, wherein the control device is configured to perform the following steps: receiving a command for yarn insertion, after receiving the command for yarn insertion, controlling the fabric take-off device (3) for yarn insertion, so that the fabric take-off device (3) takes off the knitted fabric by means of the fabric take-off device (3), thereby drawing in warp threads connected with the knitted fabric, and, during the control of the fabric take-off device (3) for yarn insertion, controlling the warp beam drive so that the warp beam is set into rotation and actively releases change warp threads wound onto the warp beam.