Cutting Insert Clamp Geometry for Tolerance-Compensating Tool Holders
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Solution Overview
Problem
Existing tool systems face challenges in achieving reliable and secure clamping of cutting inserts with considerable geometrical tolerances, leading to uneven load distribution and requiring precise grinding of the upper surface.
Innovation Solution
The tool system employs an elongated clamping groove and two clamping protrusions with a convex supporting element and a concavely curved guide surface, allowing for balanced load distribution and tilting to compensate for tolerances, eliminating the need for elaborate grinding and ensuring secure clamping even with variations in geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional clamping system with a clamp acting on the upper surface of the cutting insert is used, then the cutting insert can be secured in the insert seat, but the load distribution on the cutting insert becomes uneven and tight tolerances are required for the clamping groove
Solution Approach 1:
The supporting element is designed with a spherical protruding portion that interacts with a correspondingly curved guide surface in the holder. This spherical geometry allows the clamp to automatically self-align and compensate for tolerances in the clamping groove position and orientation, eliminating the need for tight tolerances while maintaining reliable clamping and balanced load distribution on the cutting insert.
2Reliability
If the upper surface of the cutting insert is precisely ground to achieve secure clamping, then clamping reliability improves, but manufacturing cost and complexity increase
Solution Approach 1:
The clamping system is designed to be self-aligning through the spherical supporting element and curved guide surface interaction. This self-service mechanism automatically compensates for variations in the upper surface geometry of the cutting insert, allowing the use of as-sintered surfaces from powder metallurgy processes without requiring elaborate grinding operations, thereby reducing manufacturing complexity and cost.
3Adaptability or versatility
If the clamping groove geometry varies due to production tolerances, then manufacturing flexibility improves, but clamping security deteriorates
Solution Approach 1:
The spherical protruding portion of the supporting element interacts with the curved guide surface to provide self-aligning capability. This geometric configuration allows the clamp to automatically adjust to variations in the clamping groove's position and orientation caused by production tolerances, maintaining secure clamping and balanced load distribution despite geometric variations.
Solution Approach 2:
The system utilizes the degree of freedom provided by the spherical support element to change the spatial parameters (position and orientation) of the clamp relative to the cutting insert. This parameter adjustment allows the clamping system to adapt to varying groove geometries while maintaining reliable performance.
Data Source
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AI summary
A tool system (1) is provided, comprising: a holder (10) having an insert seat (11) for holding an exchangeable cutting insert (20), the insert seat (11) having a base seat surface (12) for supporting a lower side (22) of the cutting insert (20), a first lateral seat surface (13) for supporting a first lateral side (23) of the cutting insert (20), and a second lateral seat surface (14) for supporting a second lateral side (24) of the cutting insert (20), the first and second lateral seat surfaces (23, 24) enclosing an internal angle (α) smaller than 180°, and an exchangeable cutting insert (20) mounted in the holder (10) via a clamping mechanism. The clamping mechanism comprises a clamp (30) acting on an upper surface (21) of the cutting insert (20) and a fastening screw (40) for tightening the clamp (30). The upper surface (21) of the cutting insert (20) has an elongated clamping groove (25) extending obliquely to both the first lateral seat surface (13) and the second lateral seat surface (14). The clamp (30) has a through-hole (31) for receiving the fastening screw (40), at one side of the through-hole (31) has two clamping protrusions (32) engaging the clamping groove (25) of the cutting insert (20) at positions spaced from each other, and at the other side of the through-hole (31) comprises a supporting element (33). The holder (10) has a guide surface (15) guiding the supporting element (33) in a backwards direction (B) away from the cutting insert (20) upon tightening the fastening screw (40), the backwards direction (B) having at least a directional component (d1) normal to the first lateral seat surface (13) and a directional component (d2) normal to the second lateral seat surface (14)