Chain Pin Diameter Zoning for Precise Link Chain Length Control
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Solution Overview
Problem
Existing methods for controlling the chain length of articulated chains, such as those used in bicycle drives, are complex due to the deformation of outer link plates caused by cylindrical pins with constant diameters, leading to non-uniform deformation and difficulty in adjusting chain length.
Innovation Solution
A bolt set with varying joint diameters, where the joint diameter differs from the joint areas, allowing for selection of pins with specific diameters to achieve the desired chain length without altering the joint areas, resulting in consistent deformation and simplified chain length control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If cylindrical pins with constant diameter are used to control chain length, then the chain length can be adjusted by changing pin diameter, but the outer link plates deform non-uniformly causing complex adjustment procedures
Solution Approach 1:
The pin is designed with different diameters in different regions: a larger diameter in the joint area (contacting inner chain links) and a smaller diameter in the pressing areas (contacting outer link plates). This local differentiation allows the joint area dimensions to be precisely controlled for accurate chain length, while the smaller pressing areas minimize deformation of the outer link plates, simplifying the adjustment procedure.
2Manufacturing precision
If pin diameter is increased to control chain length, then chain length adjustment is achieved, but the interference fit between openings and pin increases causing outer plate deformation
Solution Approach 1:
The pin features a larger diameter joint area for precise chain length control and smaller diameter pressing areas to minimize interference fit with the outer link plates. This reduces the deformation of the outer plates while maintaining the required chain length adjustment capability through the joint area dimensions.
Solution Approach 2:
The pin is segmented into distinct functional zones: a central joint area with larger diameter for dimensional control and chain length determination, and end pressing areas with smaller diameter for minimal deformation during assembly. This segmentation allows each zone to perform its specific function optimally without interfering with the other.
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
This approach enables easier and more effective chain length control by minimizing the impact of pin diameter changes on outer link plate deformation, allowing for precise adjustment and improved fatigue strength.
Implementation Method 1
the ends of the bolts are cylindrical. With these ends, the bolts are pressed into openings in the link plates of the outer chain links
Implementation Method 2
The interference fit between the openings and the pin causes the outer plates to be deformed. The bolts displace the material of the outer plates.
Data Source
Figure 1~2
AI summary
The present invention relates to a method for controlling the chain length of a link chain of a chain type comprising alternately arranged inner and outer chain links connected to one another by means of a chain link, wherein each outer chain link has two outer plates, each with two openings, and two pins pressed into the openings of the outer plates. The pins of the outer chain links each have a joint area in contact with the inner chain links, with a joint diameter, and two joining areas pressed into the openings of the outer plates, with a joining diameter. The object of the present invention is to provide such a method, which avoids the disadvantages known from the prior art and, in particular, leads to simpler chain length control.According to the invention, the method comprises the following steps: providing a set of bolts comprising a plurality of bolts, wherein at least two of the bolts from the set have different joint diameters of the joint areas, and in at least one of the bolts from the set, the joint diameter of the joint area differs from the joining diameter of the joining areas; determining the joint diameter of the joint area of the bolts required for a given chain length; selecting the bolts with the determined joint diameter of the joint area from the set of bolts; pressing the joining areas of the bolts into the openings in the outer plates; and completing the link chain. Furthermore, the invention also relates to the use of a bolt in such a method and to a set of bolts for such a method.