Auger Feed Screw and Spur Design for Fast, Clean Hole Drilling
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Solution Overview
Problem
Existing augers are inefficient in cutting holes at faster speeds, leading to longer drilling times and potential chipping around the edges of the holes, while also producing less clean cutting results.
Innovation Solution
The auger design includes a feed screw with a high pitch and nonsymmetrical thread profile, a cutting edge with a sharp primary angle, and a spur that extends past the cutting edge, facilitating faster rotation and cleaner hole cutting by scoring the hole before material removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the auger rotates at higher speeds to minimize drilling time, then productivity is improved, but chipping occurs around the edges of the holes and manufacturing precision deteriorates
Solution Approach 1:
The spur performs a preliminary action by scoring the hole outline before the cutting edge removes material. This pre-scoring prevents chipping during high-speed rotation while maintaining clean hole edges, resolving the contradiction between drilling speed and hole quality
Solution Approach 2:
The cutting head is segmented into distinct functional elements: the spur for scoring, the cutting edge for material removal, and the feed screw for engagement. This segmentation allows each element to perform its specific function optimally, enabling high-speed drilling without compromising hole quality
2Productivity
If the auger rotates at higher speeds to minimize drilling time, then productivity is improved, but the cutting hole becomes less clean
Solution Approach 1:
The spur scores the hole outline in advance before the cutting edge engages, creating a clean boundary that prevents material chipping during high-speed rotation. This preliminary scoring action ensures clean holes even at maximum drilling speeds
Solution Approach 2:
The helical flute provides continuous material removal and chip evacuation throughout the drilling process. This continuous action prevents material buildup and maintains clean hole walls during high-speed operation, resolving the contradiction between speed and cleanliness
Data Source
AI summary
An auger includes a body having a first end, a second end, a stem that defines an axis of rotation, and a flute helically wrapped around the stem. The auger also includes a shank at the first end of the body and a cutting head at the second end of the body. The cutting head includes a cutting edge, a cutting face adjacent the cutting edge, and a back taper surface extending from the cutting edge in a direction opposite the cutting face. The back taper surface defines a back taper angle between an axis perpendicular to the axis of rotation and the back taper surface. The back taper angle is a non-zero angle. The cutting head further includes a feed screw extending from the stem along. The feed screw includes a thread having a pitch and a depth. The pitch is larger than the depth of the thread.