Elevator Guide Rail Fishplate Positioning for Moment Reduction
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Solution Overview
Problem
In elevators with flexible hoistway structures, the large maximum moment generated at the fishplate position poses challenges for maintaining riding comfort and requires special bolts or surface treatments for joint surfaces, increasing costs.
Innovation Solution
A guide rail device with a fishplate position ratio of one-third or less of the rail fixing distance, reducing the moment acting on the fishplate and eliminating the need for special bolts or surface treatments, by strategically positioning fixing bodies in relation to the fishplate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the fishplate is installed at the intermediate position between two rail brackets to accommodate standard-length rails, then the rail installation is simplified, but the maximum moment becomes significantly large requiring special bolts or surface treatments
Solution Approach 1:
The patent applies asymmetry by positioning the fishplate at a specific asymmetric location relative to the rail brackets. The distance from the first rail bracket to the fishplate is set to one-third or less of the rail fixing distance (distance between first and second rail brackets), creating an asymmetric configuration that reduces the moment arm and thereby suppresses the maximum moment on the fishplate while maintaining practical installation feasibility
Solution Approach 2:
The patent changes the positional parameter of the fishplate from the conventional intermediate position (50% of rail length from bracket) to a specific position where the distance from the first rail bracket is one-third or less of the rail fixing distance. This parameter change optimizes the moment distribution and reduces the required joint strength
2Reliability
If special bolts or surface treatments are used to reduce moment on the fishplate, then the riding comfort is improved, but the material and installation costs increase
Solution Approach 1:
The patent changes the positional parameter of the fishplate to reduce the moment arm, which directly reduces the moment load on the fishplate joint. This parameter optimization allows the use of standard bolts and surface treatments instead of special high-strength fasteners, thereby reducing material and installation costs while maintaining sufficient riding comfort
Data Source
AI summary
Provided is a guide rail device for an elevator, which includes a plurality of fixing bodies. Among the plurality of fixing bodies, a fixing body that is the closest to a fishplate is referred to as a first fixing body, and a fixing body that is the second closest to the fishplate is referred to as a second fixing body. Further, a distance between a position of the first fixing body and a position of the second fixing body in a vertical direction is referred to as a rail fixing distance. In this case, a distance from the position of the first fixing body to a position of the fishplate in the vertical direction is one-third or less of the rail fixing distance.