Chamfered Single-Lip Drill Geometry for Straighter Deep Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing single-lip drills face challenges in producing boreholes with low hole straightness deviation and require complex, expensive grinding processes for maintaining the cutting edge, leading to high production costs and limited regrinding capabilities.
Innovation Solution
The design incorporates an inner and outer rake face with the outer rake face positioned below the rake face plane, allowing for easy production using standard grinding wheels and extending the drill's service life by reducing the need for frequent regrinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If axial structures are mounted on the rake face to shape chips, then chip shaping is improved and higher feed is allowed, but the production becomes very complicated and expensive requiring special grinding wheels for each diameter
Solution Approach 1:
The invention changes the geometric parameters of the rake face by positioning the outer rake face below the rake face plane, creating a chamfered configuration. This geometric parameter change achieves favorable chip shaping without requiring complex axial structures, thereby maintaining productivity while simplifying the production process and eliminating the need for diameter-specific grinding wheels.
Solution Approach 2:
Instead of adding axial structures upward from the rake face plane to shape chips, the invention inverts the approach by positioning the outer rake face below the rake face plane. This inverted configuration achieves chip shaping through the chamfered geometry itself, simplifying the device while maintaining or improving productivity.
2Productivity
If a chip former extends parallel to the outer edge with width significantly greater than 1 mm, then favorable chip shaping is achieved, but the drill must be ground by an amount equal to the width of the chip former, making re-sharpening time-consuming and expensive
Solution Approach 1:
The invention changes the vertical position parameter of the outer rake face, positioning it below the rake face plane. This creates a chamfered configuration that provides favorable chip shaping with a much smaller effective width than traditional chip formers, thereby reducing the amount of material that must be removed during regrinding and significantly decreasing regrinding time.
3Manufacturing precision
If the outer rake face is positioned below the rake face plane, then hole straightness deviation is reduced and production is simplified, but the cutting edge geometry becomes more complex
Solution Approach 1:
The invention segments the rake face into an inner rake face positioned at the rake face plane and an outer rake face positioned below the rake face plane. This segmentation creates a chamfered configuration that improves hole straightness while keeping each segment's geometry relatively simple, avoiding the need for complex overall rake face geometry.
Data Source
AI summary
The invention relates to a single-lip drill with an inner and an outer rake face. Very good hole straightness deviation values and endurance are obtained with the ground face according to the invention.