Sheave Device Tension Control During Crane Retraction
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Solution Overview
Problem
Existing methods for retracting and unfolding sheave devices in cranes often result in excessively high rope tension, which can lead to damage and safety risks.
Innovation Solution
A method that includes a sheave device retracting and unfolding step, a tension information detecting step, and a tension information using step, where the rope tension is monitored and adjustments are made to the winch operation based on detected tension information to prevent excessive tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the winch winds the rope at high speed during sheave device retraction, then the retraction speed is improved, but the rope tension becomes excessively high
Solution Approach 1:
The patent implements a feedback control system where a tension sensor continuously monitors rope tension during sheave device retraction. The controller receives tension information and automatically adjusts the winch winding speed to maintain tension within a safe range, preventing excessive tension while achieving efficient retraction.
Solution Approach 2:
The patent dynamically changes the winch winding speed parameter based on real-time tension conditions. When tension approaches the upper limit, the controller reduces the winding speed; when tension is within the safe range, the controller maintains or increases the winding speed, thereby optimizing retraction speed while preventing excessive tension.
2Speed
If the winch unwinds the rope at high speed during sheave device unfolding, then the unfolding speed is improved, but the rope tension becomes excessively high
Solution Approach 1:
The feedback control system operates bidirectionally, monitoring rope tension during both retraction and unfolding operations. The controller adjusts the winch unwinding speed based on real-time tension information, preventing excessive tension buildup during rapid unfolding while maintaining efficient operation.
Solution Approach 2:
The patent dynamically adjusts the winch unwinding speed parameter in response to tension conditions. When tension approaches the upper limit during unfolding, the controller reduces the unwinding speed; when tension is within the safe range, the controller maintains or increases the unwinding speed, thereby optimizing unfolding speed while preventing excessive tension.
3Ease of operation
If the winch winding speed is not adjusted according to sheave device movement speed, then the operation simplicity is improved, but the rope tension becomes excessively high
Solution Approach 1:
The patent implements a self-regulating system where the controller automatically adjusts the winch speed based on real-time tension information from the tension sensor. This eliminates the need for manual speed adjustment by the operator, maintaining operational simplicity while preventing excessive tension through automated control.
Solution Approach 2:
The feedback mechanism provides automatic speed regulation without requiring operator intervention. The tension sensor continuously monitors rope tension and the controller autonomously adjusts the winch winding/unwinding speed to maintain safe tension levels, combining ease of operation with tension control.
Data Source
AI summary
A sheave device retracting and unfolding step includes winding and unwinding a rope by a winch, with a lifting side sheave device lifted by an assist crane. A tension information detecting step includes detecting rope state information on the rope when the sheave device retracting and unfolding step is performed. A tension information using step includes performing at least one of notification to a worker and drive control of the winch based on the rope state information detected in the tension information detecting step