CBN Cutting Insert with Internal Coolant Path for Edge Cooling
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Solution Overview
Problem
The existing throwaway cutting inserts are ineffective in cooling due to an inclined coolant supply hole design that reduces coolant ejection towards the cutting edge, leading to inadequate cooling of the cutting edge during machining.
Innovation Solution
A cutting insert with a coolant flow path inside the cutting edge portion, where the rake face is inclined towards the bottom surface, ensuring a decreasing distance to the coolant ejection outlet, facilitating effective coolant supply to the cutting edge, and featuring a cutting edge formed of sintered material with cubic boron nitride particles for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the coolant supply hole is inclined so that the distance from the coolant supply hole to the bottom surface increases gradually toward its opening in the breaker surface, then the structure is simplified and manufacturing is easier, but coolant ejection toward the cutting edge is reduced and cooling effectiveness deteriorates
Solution Approach 1:
Instead of inclining the coolant hole away from the cutting edge as in conventional designs, the patent inverts this approach by positioning the coolant hole such that it inclines toward the cutting edge, with the distance from the hole to the bottom surface decreasing gradually toward the opening. This inversion enables coolant to be ejected directly toward the cutting edge, achieving effective cooling while maintaining manufacturing simplicity.
2Device complexity
If coolant ejection is directed away from the cutting edge for structural stability, then the coolant flow path is simplified, but cooling effectiveness at the cutting edge deteriorates
Solution Approach 1:
The patent applies local quality by creating a localized coolant ejection zone directly at the cutting edge area. The coolant hole is positioned and inclined specifically in the region where cooling is most needed, with its opening facing the cutting edge. This localized configuration ensures that coolant is delivered precisely where temperature control is critical, without requiring complex overall flow path design.
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 design enables efficient cooling of the cutting edge, suppressing temperature increases and maintaining performance in high-productivity processing of difficult-to-cut materials by ensuring consistent and effective coolant supply to the cutting edge.
Implementation Method 1
A coolant flow path is formed in an inside of the cutting edge portion. The coolant flow path includes a coolant ejection outlet that is open in the rake face.
Implementation Method 2
The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge. A distance from the coolant flow path to the bottom surface is constant or decreases gradually toward the coolant ejection outlet.
Data Source
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AI summary
A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge. A coolant flow path is formed in an inside of the cutting edge portion. The coolant flow path includes a coolant ejection outlet that is open in the rake face. A distance from the coolant flow path to the bottom surface is constant or decreases gradually toward the coolant ejection outlet.