Drill Body Fluid-Hole Geometry for Coolant Flow and Tip Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drill designs face challenges in effectively supplying cutting fluid to the cutting region while maintaining stiffness, especially when a removable cutting edge member is mounted, as the leading end part requires both fluid supply and structural integrity.
Innovation Solution
A drill body design featuring a fluid hole with a changing cross-sectional shape from circular to non-circular, longer in the circumferential direction, which passes through an inter-groove solid part, and a recessed mounting part for the cutting edge member, allowing efficient fluid flow and maintaining stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a flow hole is provided inside the drill body to supply cutting fluid to the cutting region, then cutting fluid supply is improved, but stiffness of the leading end part deteriorates
Solution Approach 1:
The hole cross section is designed to be non-circular and elongated in the circumferential direction specifically in the region where the hole passes through the inter-groove solid part. This local geometric modification allows the hole to provide adequate flow area for cutting fluid supply while minimizing the impact on the structural stiffness of the leading end part.
Solution Approach 2:
The hole cross section transitions from a circular shape to a non-circular shape that is longer in the circumferential direction. This dimensional change in the hole geometry allows the flow path to be optimized for fluid supply while the hole is positioned and shaped to preserve the structural integrity of the surrounding inter-groove solid part.
2Ease of repair
If a mounting part is provided in the leading end part for mounting a removable cutting edge member, then cutting edge replacement is improved, but stiffness of the leading end part deteriorates
Solution Approach 1:
The leading end part is segmented into a mounting part for the removable cutting edge member and an inter-groove solid part that provides structural support. The fluid hole is specifically positioned to pass through the inter-groove solid part rather than through the mounting part, separating the functional requirements of cutting edge replacement and structural stiffness.
3Ease of manufacture
If the hole cross section is circular, then manufacturing is simplified, but fluid flow efficiency deteriorates
Solution Approach 1:
The hole cross section parameters are changed from a standard circular shape to a non-circular shape that is elongated in the circumferential direction. This parameter modification optimizes the hole geometry for fluid flow efficiency while the patent acknowledges this increases manufacturing complexity compared to simple circular holes.
Data Source
AI summary
A drill body is provided which includes a flow hole capable of appropriately supplying a cutting region with a cutting fluid while securing stiffness of a leading end part. The drill body includes: a body part which extends in a rod shape from a base end part toward a leading end part; a discharge groove which is provided around a central axis of the body part in order to discharge chips; a fluid hole which is provided such that at least a part thereof passes through an inside, of the body part, of an inter-groove solid part of the discharge groove and which causes a fluid to flow from a side of the base end part toward a side of the leading end part; and a mounting part which is provided in the leading end part and which is for mounting a removable cutting edge member, wherein the mounting part has a recessed part which is provided along the central axis of the body part from an end surface of the leading end part, and a hole cross section of the fluid hole changes from a circular shape to a non-circular shape which is longer in a circumferential direction than in a radial direction in an axial cross section of the body part midway along a path of the fluid hole from the base end part toward the leading end part and assumes a non-circular shape in a portion which passes a side part of the recessed part.