Single-Lip Drill Rake-Face Grooves for Deep-Hole Chip Breaking
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Solution Overview
Problem
Conventional deep hole drills face challenges in machining tough and long-chipping materials, requiring high energy and leading to increased tool wear and stress, with existing chip breakers being difficult to manufacture, regrind, and having limited service life.
Innovation Solution
A deep hole drill design featuring two parallel longitudinal grooves on the rake face, which are relatively wide and recessed, forming a ridge that opens into the cutting tip, allowing for the creation of two chips that curl and break, reducing chip width and improving removal efficiency, and allowing for easier production and regrinding without the need for elevations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional chip breakers (elevations) are provided on the rake face, then chip breaking is achieved, but manufacturing and regrinding become difficult and service life is limited
Solution Approach 1:
Instead of providing elevations (protrusions) on the rake face as conventional chip breakers, the invention inverts the approach by providing recesses (longitudinal grooves) in the rake face. This inversion simplifies manufacturing and regrinding processes while achieving effective chip breaking through the formation of a compression zone at the bottom of the grooves.
2Reliability
If wide longitudinal grooves are provided in the rake face, then chip breaking is improved and manufacturing is easier, but the ridge becomes narrower
Solution Approach 1:
The invention changes the geometric parameters of the groove cross-section, specifically setting the groove width to at least 0.05 times the drill diameter and the groove depth to at least 0.1 times the drill diameter. These parameter changes create an optimized balance between effective chip breaking and maintaining sufficient ridge width for structural integrity.
3Productivity
If high drive power is used to machine tough materials, then material removal is achieved, but thermal load and tool wear increase
Solution Approach 1:
The invention changes the chip formation parameters by creating two separate chips through the longitudinal grooves instead of one wide chip. This parameter change in chip geometry reduces the contact area and friction between chip and tool, thereby reducing thermal load and tool wear while maintaining effective material removal.
Data Source
AI summary
The invention relates to single-lip drills in which two longitudinal grooves are formed in the rake face. They are arranged in the longitudinal direction of the tool, spaced apart from one another by a ridge and favor chip breaking.