Drill Tip Thinning Geometry for Axial Chip Removal
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Solution Overview
Problem
Existing drilling tools face challenges in achieving efficient chip removal with low machining forces and high production costs, particularly in maintaining effective chip removal near the center of the drill.
Innovation Solution
A drilling tool design featuring two main cutting edges with an arc-shaped course, connected via a cross cutting edge, and a thinning introduced into the drill face with a specific opening angle between 85° and 95°, ensuring axial chip removal and reduced friction, along with a method for producing the tool using surface grinding that extends the thinning into the center for enhanced chip guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional chip groove design is used, then chip removal is achieved, but chip removal near the center is ineffective and machining forces are high
Solution Approach 1:
The patent applies local quality by creating a point thinning with a specific opening angle (85°-95°) concentrated at the center region of the drill tip. This localized geometric modification optimizes chip flow specifically in the central area where conventional designs fail, without altering the overall drill geometry. The thinning starts at the transition point and connects to the main cutting edge without a kink, creating a smooth chip path that reduces friction and machining forces.
2Manufacturing precision
If multiple grinding operations are performed to achieve precise thinning geometry, then manufacturing precision is improved, but production cost increases
Solution Approach 1:
The patent merges multiple grinding operations into a single surface grinding process. By defining the thinning geometry through specific parameters (opening angle of 85°-95°, starting at the transition point, connecting without kink), the complex multi-step grinding process is consolidated into one operation, reducing manufacturing complexity and cost while maintaining precise geometric control.
Solution Approach 2:
The invention uses parameter changes by specifying the opening angle of the point thinning within a precise range (85°-95°) and defining its geometric characteristics (starting position at transition point, smooth connection to main cutting edge). These controlled parameter variations enable accurate thinning geometry to be achieved through a simplified single-grinding process, balancing precision with manufacturing ease.
Data Source
Figure 1a~1c
Figure 1d
Figure 2a~2b
AI summary
Drilling tool with two main cutting edges (2) with at least a partially arc-shaped profile, which are connected to each other via a transverse cutting edge (6), a drill face (4), a drill longitudinal axis (L) about which the drilling tool (1) is rotatable in a direction of rotation (R), a drill tip (3) lying on the drill longitudinal axis (L), two flutes (5) extending along the drill longitudinal axis (L), webs (7) formed between the flutes (5) which form a back (8) circumferentially, a point (12) formed in the drill face (4), wherein, with reference to a frontal view of the drill face (4), an opening angle (cp) of a flute (5) is formed on the drill face (4), which: in the case of a conical grinding of the drill face (4) is defined as being clamped between - an imaginary connection of the drill tip (3) with a cutting edge corner (9) of the main cutting edge (2) and - an imaginary connection of the drill tip (3) to a rear corner (10),which is formed on the back (8) at the transition of the clearance surface (11) into the chip groove (5), is defined in a surface grinding of the drill face (4) as being clamped between - an imaginary connection of the drill tip (3) with a cutting edge (9) of the main cutting edge (2) and - a radially outward extending section of a contour (14) of the pointing (12), which has an opening angle (cp) between 85° and 95°, and the pointing (12) is introduced into the drill face (4) such that a normal distance (NA) of an internal point of the pointing (12) to an imaginary connection of the drill tip (3) with a cutting edge (9) is less than or equal to the normal distance (NU) of a transition point (U) between the main cutting edge (2) adjoining the pointing (12) and the chisel edge (6) to the imaginary connection of the drill tip (3) with a cutting edge (9),wherein the pointed end (12) starts at the transition point (U) and connects to the adjacent main cutting edge (2) without a kink.