Folding Roller Control for Stepper Motor Phase Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Stepper motors used in sheet-processing apparatuses can become out of phase due to large friction forces between folding rollers and sheets or folding blades, leading to inaccurate folding and reduced productivity.
Innovation Solution
A control unit is implemented to stop or decelerate the rotation of folding rollers when the thrusting member is pulled out of the folding position, using a stepper motor as the driving member, and determining the control actions based on image-forming conditions such as the number of sheets and paper weight to manage friction forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a stepper motor is used as the driving source of the folding rollers to improve folding accuracy, then the sheet can be located on an accurate position, but the stepper motor may be stepped out of phase when there is large friction force between the folding roller and the sheet or between the sheet and the folding blade
Solution Approach 1:
The control unit stops the folding rollers in advance before the folding blade is completely pulled out, preventing the large friction force that would cause the stepper motor to step out of phase. This preliminary stopping action eliminates the harmful friction effect before it occurs.
Solution Approach 2:
The system dynamically adjusts the rotation state of the folding rollers based on the real-time position of the folding blade. The control unit monitors the blade position and controls the rollers to stop when the blade is at a specific position, creating a dynamic control strategy that prevents motor steppout while maintaining folding accuracy.
2Productivity
If the folding rollers continue rotating after the thrusting member is pulled out, then productivity is maintained, but large friction force occurs between the folding roller and the sheet or between the sheet and the folding blade causing the stepper motor to step out of phase
Solution Approach 1:
The control unit stops the folding rollers in advance before the folding blade is completely pulled out, preventing the large friction force that would cause the stepper motor to step out of phase. This preliminary stopping action eliminates the harmful friction effect before it occurs.
Solution Approach 2:
The control unit monitors the position of the folding blade and uses this feedback information to control the rotation state of the folding rollers. Based on the detected blade position, the control unit determines whether to stop or continue rotating the rollers, creating a closed-loop control system that prevents motor steppout while maintaining productivity.
3Reliability
If the folding rollers are stopped when the thrusting member is pulled out, then the stepper motor remains in phase, but additional control complexity is introduced
Solution Approach 1:
The control unit monitors the position of the folding blade and uses this feedback information to control the rotation state of the folding rollers. Based on the detected blade position, the control unit determines whether to stop or continue rotating the rollers, creating a closed-loop control system that prevents motor steppout while maintaining productivity.
Data Source
AI summary
In a saddle-stitching apparatus, when a sheet is transported to a center-folding unit, a folding blade moves from a retrieved position to a nip position between a pair of folding rollers. A forward end of the folding blade comes into contact with a fold of the sheet, so that the sheet is folded along the fold. When the sheet is attached to the nip position between the folding rollers, the folding rollers start rotating and then, the folding blade inserts the center-folded sheet between the folding rollers. After the center-fold finishing is completed, the rotations of the folding rollers stop in timing at which the folding blade is pulled out of the nip position between the folding rollers. When pulling the folding blade out of the nip position between the folding rollers, the rotations of the folding rollers restart.