Variable Cone Angle Braiding for Composite Connecting Rods

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for manufacturing composite material connecting rods are inadequate in producing components with varying mechanical qualities, as they require complex and expensive processes to add material locally, especially at ends subjected to higher stresses, and existing braiding machines are not compatible with large mechanical components.

Innovation Solution

A braiding method that includes a reconfiguration step to modify the angle of the cone formed by reinforcing fibers and adjust the mandrel feed rate and reel rotation speed, allowing for different fiber inclinations and mechanical properties in various regions of the connecting rod.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If material is added locally at the ends to increase mechanical strength and fatigue resistance, then the mechanical qualities of the connecting rod are improved, but the manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvemechanical strength and fatigue resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies local quality by varying the fiber inclination angle along the length of the connecting rod. The ends (yokes) have a first inclination angle optimized for multidirectional stresses, while the main body has a second inclination angle optimized for longitudinal stresses. This allows different mechanical properties in different regions without adding material or using complex manufacturing processes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of fiber inclination angle along the longitudinal axis of the connecting rod. By controlling the angle of the cones formed by fibers during braiding, the mechanical properties are optimized for different regions: higher inclination at ends for multidirectional strength, lower inclination in the body for longitudinal strength, eliminating the need for additional material.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a braiding machine with programmable parameters is used to vary fiber density along the tube, then the mechanical qualities can be varied along the component, but the machine cost and complexity increase and it is incompatible with large mechanical components

Engineering Contradiction:
Improveability to vary mechanical qualitiesVSAvoidmachine complexity and cost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the connecting rod into distinct regions (ends/yokes and main body) with different mechanical requirements. Each region is braided with fibers at different inclination angles achieved through different cone angles during the braiding process, allowing region-specific optimization without requiring a complex programmable braiding machine.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses dynamic adjustment of the cone angle during the braiding process to vary fiber inclination along the length of the connecting rod. By changing the angle at which fibers converge on the mandrel, the system dynamically adapts fiber orientation to match the mechanical requirements of different regions, achieving versatility with a simple braiding machine.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2655713B1Process for braiding reinforcing fibres with inclinasion variation of the braided fibres
Publication Date: 2018.07.18 AIRCELLE SA
  • EP2655713B1 patent drawingFigure 1~3
  • EP2655713B1 patent drawingFigure 4A~5C
  • EP2655713B1 patent drawingFigure 6A~7C

AI summary

A method of braiding reinforcing fibers on a mandrel (8) with a machine having a ring (9) carrying at least two series of reels of fibers, by moving the mandrel at a predetermined forward speed while moving the two series of reels along the ring (9) so that they cross while rotating in opposite directions and at a predetermined speed of rotation about an axis (AX) of the ring. The braid is formed on the mandrel (8) in the vicinity of a region of convergence (R) of the fibers that together define a conical shape (C). The method comprises: a step of reconfiguring the machine in which the angle (a2) at the apex of the cone (C) defined by the fibers takes on a new value (a2); and a step of restarting braiding in which the movement of the reels along the ring (9) and the forward movement of the mandrel (8) are re-established with a new speed of rotation and a new speed of advance.