Twist Drill Chisel Edge Concave Recesses Feed Force Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing twist drills require high power and torque to move through workpieces due to the chisel edge's cutting function, leading to increased power consumption and material removal challenges.
Innovation Solution
A twist drill design featuring a cutting head with a chisel edge and two concave recesses on either side, reducing the negative cutting angle and enhancing material flow, thereby decreasing feed force and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the web and chisel edge are made larger to maintain structural integrity, then the drill tip stability is improved, but power consumption and torque requirements increase
Solution Approach 1:
The web is segmented into multiple sections with varying thicknesses - thicker at the heel for stability and thinner at the tip for reduced power consumption. The chisel edge is also segmented with relief grooves that create discrete cutting zones rather than a continuous thick structure.
Solution Approach 2:
Different portions of the web have different thicknesses optimized for their specific functions - the heel portion maintains greater thickness for structural support and stability, while the tip portion is thinned to reduce power consumption and torque requirements during drilling operation.
2Use of energy by moving object
If the chisel edge length is reduced to lower power consumption, then power and torque consumption decrease, but material removal capability is worsened
Solution Approach 1:
Relief grooves are introduced as intermediary features between the chisel edge and the web. These grooves facilitate material flow and chip evacuation, enabling effective material removal even with a reduced chisel edge length, thereby maintaining productivity while reducing power consumption.
Solution Approach 2:
The design adds a dimensional feature (relief grooves) that run longitudinally along the web, creating a three-dimensional material flow path. This allows material to be efficiently redirected and evacuated without requiring a longer chisel edge, thus maintaining material removal capability with reduced power consumption.
3Force
If the chisel edge is made sharper to reduce feed force, then power consumption decreases, but the negative cutting angle increases causing material flow problems
Solution Approach 1:
The relief grooves introduce curved surfaces that guide material flow smoothly around the chisel edge. This curvature compensates for the increased negative cutting angle by providing a gradual material flow path, preventing material pile-up and facilitating efficient chip evacuation while maintaining reduced feed force.
Data Source
Figure 1~2
Figure 3a~3b
Figure 3c
AI summary
A twist drill (21) includes a cutting head (25) including a drill tip (27). The drill tip (27) includes a chisel edge (41) defining the forwardmost area of the cutting head, and two main cutting edges (43a, 43b), each main cutting edge (43a, 43b) extending between the chisel edge (41) and an outer end (45a, 45b) of the main cutting edge. The chisel edge (41) forms an acute angle (θ) with a line (L) extending between the top outer ends (45a, 45b) of the main cutting edges (43a, 43b). The drill tip (27) further includes two concave recesses (47a, 47b), one concave recess (47a, 47b) of the two concave recesses (47a, 47b) being disposed on each side of the chisel edge (41), the line (L) intersecting the two concave recesses (47a, 47b).