Elevator Rope Break Detection via Car-Mounted Sensor
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Solution Overview
Problem
Elevator devices require a complex configuration with multiple sensors and signal lines to detect wire or strand breaks in ropes, especially in systems with many sheaves, leading to increased complexity and potential inaccuracies.
Innovation Solution
A break detection system that uses a sensor with output signals varying due to rope vibrations, detection means for abnormal variations, storage for associating position data with detection events, and arithmetic means to determine the presence of breaks based on a determination score, simplifying the configuration and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors are installed at each sheave position to detect wire or strand breaks, then detection accuracy is improved, but device complexity increases due to multiple sensors and extended signal lines
Solution Approach 1:
The patent extracts the break detection function from multiple sheave positions and concentrates it at a single location. By using a detection member that moves with the car to detect breaks at the suspension sheave, the system eliminates the need for sensors at every sheave position, thereby reducing device complexity while maintaining detection accuracy.
Solution Approach 2:
The detection member serves multiple functions: it detects wire breaks, strand breaks, and monitors rope condition all through a single sensor location. This multi-functional approach eliminates the need for separate detection systems at each sheave, reducing overall system complexity.
2Reliability
If multiple sensors are installed around the main rope path, then break detection capability is improved, but installation and maintenance difficulty increase
Solution Approach 1:
The patent consolidates multiple detection functions into a single detection member that moves with the car. This extraction of the detection function to one location simplifies installation and maintenance procedures while maintaining comprehensive break detection capability through the suspension sheave monitoring point.
3Measurement precision
If sensors are positioned at suspension sheave of counterweight, then break detection coverage is improved, but signal line length increases
Solution Approach 1:
The patent positions the detection member at the suspension sheave of the counterweight, extracting the detection function to this strategic location. This provides comprehensive break detection coverage for the entire rope system while the signal line length is managed through this centralized detection point.
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
The system effectively detects wire or strand breaks with high accuracy and simplicity, reducing the need for multiple sensors and signal lines, particularly in systems with many sheaves.
Implementation Method 1
a sensor (14) having an output signal, the output signal varying when vibration is generated in a main rope (4)
Data Source
AI summary
A break detection device includes a sensor, an abnormal variation detection unit (22), a storage unit (20), an arithmetic unit (23), and a break determination unit (24). The arithmetic unit (23) increases a determination score when the abnormal variation detection unit (22) detects occurrence of an abnormal variation when a car (1) passes a position stored in the storage unit (20). The arithmetic unit (23) decreases the determination score when the abnormal variation detection unit (22) does not detect the occurrence of the abnormal variation when the car (1) passes the position. The break determination unit (24) determines whether or not a broken portion is present in a rope on the basis of the determination score.