Draft Device Cam Control for Roller Cleaning Separation
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Solution Overview
Problem
In draft devices, fiber pieces tend to accumulate between top rollers and cleaning modules due to short separation times at high rotation speeds, leading to inefficiencies in fiber removal.
Innovation Solution
The draft device incorporates control members on the rotation shafts of top rollers with adjustable angles for separating and contacting cleaning modules, ensuring longer separation times and preventing fiber accumulation, even at high speeds, by using cams with specific angles and attachment methods to manage the timing and position of cleaning module interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the top roller rotation speed is increased to improve productivity, then the cleaning efficiency should improve, but the separation time between cleaning module and top roller becomes too short causing fiber accumulation
Solution Approach 1:
The cam mechanism transforms the uniform rotational motion of the top roller into non-uniform angular displacement of the cleaning module. By designing the cam profile with specific curvature variations, the system achieves dynamic adjustment of separation and contact durations, allowing extended separation time at high rotation speeds while maintaining effective cleaning contact time.
Solution Approach 2:
The invention changes the angular displacement parameters of the cleaning module by using a cam with specifically designed profile. The cam converts the constant rotational speed into variable angular position over time, effectively increasing the separation angle and duration without reducing the top roller rotation speed, thus resolving the time loss issue while maintaining productivity.
2Reliability
If the separation angle is increased to prevent fiber accumulation, then the separation time improves, but the contacting time for cleaning may be reduced
Solution Approach 1:
The cam mechanism enables dynamic optimization of both separation and contact phases. The cam profile is designed to provide sufficient separation angle for fiber drop-off while maintaining adequate contact angle for effective cleaning. The non-uniform angular displacement ensures that both phases receive appropriate duration based on the cam geometry rather than being constrained by uniform rotation.
3Ease of manufacture
If all cams are configured with the same separation angle to simplify the device, then the manufacturing is easier, but fiber pieces accumulate at high rotation speeds
Solution Approach 1:
The invention applies different cam configurations to different top rollers based on their specific operational requirements. The downstream cam is designed with larger separation angle characteristics suitable for high-speed operation where fiber accumulation is more problematic, while upstream cams may have different profiles optimized for their local conditions. This localized optimization ensures reliable fiber removal at each position in the drafting system.
Data Source
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AI summary
To provide a draft device capable of preventing fiber pieces from being accumulated between a top roller and a cleaning module, and a spinning machine equipped with such a draft, device. The draft device includes a plurality of pairs of rollers (14, 15, 16, and 17), and a cleaning module (64) arranged to make contact with and separate from a middle top roller (16b). The cleaning module (64) is separated from the middle top roller (16b) within a first angle (P) of 50° or more and 300° or less around the rotation shaft of the middle top roller (16b), and is brought into contact with the middle top roller (16b) within a second angle obtained by subtracting the first angle from 360° around the rotation shaft of the middle top roller (16b).