Abrasive Machining Tool for Composite Material Tapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Machining composite material parts, particularly those with organic matrices, is challenging due to susceptibility to delamination and fiber tearing, making drilling and tapping operations difficult and potentially weakening the mechanical strength, especially in complex geometries and large-sized parts.
Innovation Solution
A machining tool with projecting annular ribs covered in abrasive grains, designed to abrade the material without cutting teeth, allowing for single-pass or minimal-pass hole tapping without delamination or fiber degradation, ensuring mechanical strength and reducing the need for external reinforcement or increased material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If drilling and tapping operations are performed on CMO material parts, then fixing plates can be installed on compressor casings, but the mechanical strength of the part is weakened due to fiber tearing and delamination
Solution Approach 1:
The patent replaces traditional cutting taps with a rubbing tool that has an abrasive surface. Instead of using cutting teeth that remove material through mechanical cutting forces, the rubbing tool creates threads by friction and abrasion against the CMO material, significantly reducing cutting forces and avoiding fiber tearing and delamination.
Solution Approach 2:
The patent changes the machining mechanism from cutting-based to abrasion-based. The rubbing tool's abrasive surface progressively wears down the CMO material through friction, allowing thread formation with much lower forces compared to traditional tapping, thereby preserving the mechanical integrity of the composite material.
2Strength
If reinforcement material is added to compensate for machining weakening, then the mechanical strength is maintained, but the mass of the turbine engine increases
Solution Approach 1:
By replacing cutting taps with a rubbing tool, the patent eliminates the need for reinforcement measures. The abrasion-based machining preserves the original mechanical strength of the CMO material, avoiding the need to add reinforcement material that would increase the engine's mass.
3Manufacturing precision
If traditional taps with cutting teeth are used for tapping holes in CMO material, then thread formation is achieved, but significant cutting forces cause deformation, heating, delamination, and fiber bursts
Solution Approach 1:
The patent substitutes the cutting mechanism with an abrasion mechanism. The rubbing tool's abrasive surface creates threads through friction and material removal by abrasion rather than cutting, dramatically reducing the forces applied to the CMO material and eliminating the harmful effects of deformation, heating, delamination, and fiber bursts.
Solution Approach 2:
The abrasive surface acts as an intermediary between the tool and the CMO material. Instead of direct cutting contact that causes high stresses, the abrasive grains progressively wear away material through friction, mediating the interaction to reduce harmful effects while still achieving thread formation.
4Strength
If multiple passes are used to tap holes in CMO material, then material health is preserved, but machining time and productivity are reduced
Solution Approach 1:
The rubbing tool with abrasive surface can perform tapping in a single pass while preserving material health. The low cutting forces generated by abrasion allow the tool to continuously remove material and form threads without causing delamination or fiber tearing, eliminating the need for multiple passes required by traditional tapping methods.
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 tool effectively taps holes in composite materials with reduced fiber tearing and resin degradation, ensuring material health and mechanical strength, while minimizing machining forces and costs by allowing large chip removal volumes in a single pass.
Implementation Method 1
The outer surface of which is covered with abrasive grains... proceed progressively for the digging of the grooves... by abrasion of said material by means of the ribs of the rotating tool
Data Source
Figure 1~2
Figure 3~4
AI summary
A tool for machining a wall of a workpiece, in particular made from a composite material. According to the invention, the tool (1) for machining a wall (P) of a workpiece, in particular made from a composite material, intended for cutting a groove (S) in said wall (P), said tool (1) comprising a head (3) mounted integrally with a rod (2) having a longitudinal axis L-L and capable of being driven in rotation about the latter, said head (3) comprising at least one main protruding annular rib (5), whereof the outer surface is covered with abrasive grains of predetermined particle size and whereof the radial height (h) corresponds to the depth of said groove (S) to be cut, and at least one auxiliary protruding annular rib (6), whereof the outer surface is covered with abrasive grains of predetermined particle size and whereof the radial height is less than the radial height of a main rib (5), is characterised in that said auxiliary rib comprises two circular ridges separated by a ring band (8) that is flat and preferably conical in shape.