Cutting Tool Insert Seat Layout for Deflection and Chatter Suppression
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Solution Overview
Problem
Cutting tools used for grooving in hole bottom surfaces face issues with reduced ejection performance of chips and interference between the cutting material and the cutting insert, leading to damage of the cutting edge due to insufficient support stiffness, particularly during inner-diameter machining.
Innovation Solution
The design includes an insert seat with a deep seat portion and a shallow seat portion, along with rotation suppression portions and an engagement projected part, which increases the thickness of the body on the opposite side of the cutting edge, enhancing support stiffness without altering the tool's size, thereby reducing deflection and chatter during machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the body is elongated to increase the distance from the fulcrum to the load, then the deflection of the cutting edge is suppressed, but the body itself deflects due to its own insufficient stiffness
Solution Approach 1:
The insert seat is segmented into a deep seat portion and a shallow seat portion. The deep seat portion (depth L1) is positioned at the leading end side to support the cutting insert, while the shallow seat portion (depth L2, where L2 < L1) is positioned at the base end side. This segmentation allows the deep seat portion to provide adequate support for suppressing cutting edge deflection, while the shallow seat portion maintains body thickness and stiffness without requiring overall body elongation.
Solution Approach 2:
Different depths of the seat portions are applied at different locations along the axial direction. The deep seat portion is localized at the leading end side where maximum support is needed for the cutting insert, while the shallow seat portion is localized at the base end side where maintaining body stiffness is critical. This local differentiation resolves the contradiction by providing targeted support exactly where needed without compromising overall structural rigidity.
2Strength
If the depth of the insert seat is increased to improve support stiffness, then the cutting insert is better supported, but the thickness of the body is reduced
Solution Approach 1:
The insert seat depth is segmented into two distinct portions: a deep seat portion with depth L1 at the leading end side and a shallow seat portion with depth L2 at the base end side, where L2 < L1. This segmentation enables the deep seat portion to provide sufficient support stiffness for the cutting insert while the shallow seat portion preserves adequate body thickness, thereby resolving the contradiction between support stiffness and body thickness.
Solution Approach 2:
Instead of uniformly increasing the insert seat depth along the entire axial direction, the invention varies the depth in the axial dimension, creating a stepped structure. This dimensional variation allows the seat depth to be increased only where necessary (at the leading end side) while maintaining adequate body thickness elsewhere (at the base end side), effectively resolving the trade-off between support stiffness and body thickness.
Data Source
AI summary
A body of a cutting tool and a cutting insert which can further improve support stiffness of the cutting insert are provided.A body of a cutting tool includes an insert seat provided on a leading end part of the body, a screw hole with which a fastening screw is screwed, a deep seat portion provided at a deep part in the insert seat in an axial direction of the screw hole, a receiving portion receiving a contact portion of the cutting insert, a wall portion having a base-end side rotation suppression portion which stops rotation of the cutting insert, and a shallow seat portion, the depth of a seat thereof being shallower than a part with the receiving portion, wherein the base-end side rotation suppression portion is positioned not to overlap the deep seat portion when viewed along a screw-hole axis.