Turning Insert Recess Structure for Stable Back Metal Support
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Solution Overview
Problem
Existing turning tools face challenges in extending the life of the tool main body and achieving stable fixation of cutting inserts due to deformation issues caused by point contact between the back metal and the cutting insert during cutting operations.
Innovation Solution
The design incorporates a protrusion on the back metal with a shape resembling the recesses on the cutting insert, allowing for surface contact instead of point contact, which disperses the load and increases the wall thickness of the back metal, thereby enhancing stability and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the back metal is made thin to reduce material usage and simplify structure, then the device complexity and material consumption are reduced, but the back metal deforms under cutting load due to point contact, reducing reliability and service life
Solution Approach 1:
The invention transitions from point contact (zero-dimensional contact) to surface contact (two-dimensional contact) by providing a protrusion on the back metal that fits into a recess on the cutting insert. This dimensional change increases the contact area, distributing the cutting load across a larger surface area of the back metal, thereby preventing deformation even when the back metal is made thin.
2Reliability
If the back metal wall thickness is increased to prevent deformation, then the reliability and service life are improved, but the device complexity and material consumption increase
Solution Approach 1:
Instead of increasing wall thickness in all directions, the invention introduces a protrusion feature that creates surface contact with the cutting insert's recess. This allows the back metal to maintain thin walls overall while having localized reinforcement through the protrusion, distributing loads efficiently without adding significant material or complexity.
3Ease of manufacture
If point contact is used between back metal and cutting insert, then the structure is simpler and material usage is reduced, but the cutting load is concentrated causing back metal deformation and reduced service life
Solution Approach 1:
The invention changes the contact geometry from point contact to surface contact by providing a protrusion on the back metal that fits into a recess on the cutting insert. This increases the contact area, distributing the cutting load across a larger surface area, thereby preventing deformation even with a relatively simple back metal structure.
4Productivity
If the cutting insert has an equilateral triangular shape for 120-degree rotation usability, then the productivity and versatility are improved, but the back metal becomes thin and prone to deformation
Solution Approach 1:
The invention introduces a protrusion with a shape resembling the recesses on the cutting insert. This protrusion creates surface contact that distributes loads across the back metal, enabling the use of thin-walled back metals even with equilateral triangular cutting inserts that require 120-degree rotation for multi-position usability.
Data Source
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AI summary
A cutting insert 2 includes an upper surface 6, a lower surface 7 on a side opposite to the upper surface 6, and a peripheral side surface 8 connecting the upper surface 6 and the lower surface 7. A cutting edge 61 is formed in at least a part of a first ridgeline 60 where the upper surface 6 and the peripheral side surface 8 intersect. At least one bottomed recess 10 recessed from the lower surface 7 to the upper surface 6 is formed in an outer peripheral portion of the lower surface 7. Each of the recesses 10 is formed in a substantially triangular shape having a first vertex P, a second vertex Q, and a third vertex R. The first vertex P and the second vertex Q are respectively positioned on a second ridgeline 70 where the lower surface 7 and the peripheral side surface 8 intersect. The third vertex R is positioned on the lower surface 7 and separated from the second ridgeline 70.