Hexahedral Pin Miller Insert with Wedge Planes
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Solution Overview
Problem
Conventional pin miller inserts for machining crank shafts face challenges in achieving a large dish angle to minimize contact resistance and ensuring strong cutting edges and durable clamping screws.
Innovation Solution
A hexahedral pin miller insert with inclined wedge-shaped planes and arcuate surfaces allows for a dish angle and negative rake angle, enhancing cutting edge strength and securing stable clamping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a rectangular type insert with parallelogrammic rake face is used to allow a large dish, then the contact on the work-piece is decreased, but error proofing in manufacturing becomes difficult and positive axial rake angle is hard to achieve
Solution Approach 1:
The insert uses a symmetric parallelogrammic geometry with inclined planes that create asymmetric cutting surfaces relative to the workpiece. This allows the dish formation while maintaining manufacturing simplicity through symmetric fabrication processes. The symmetry in geometry compensates for the asymmetric cutting action, enabling error-proof manufacturing.
2Ease of manufacture
If a parallelogrammic type insert with rectangular rake face is used, then manufacturing is easier, but it does not provide a large dish and has large contact resistance on the work-piece
Solution Approach 1:
The insert introduces inclination in the axial dimension by creating inclined planes that are not parallel to the rake face. This additional dimensional feature (inclination angle) enables dish formation without changing the basic rectangular/parallelogrammic footprint geometry, thus maintaining manufacturing ease while reducing contact resistance through the created dish.
3Object-affected harmful factors
If the insert is designed to allow a large dish angle, then contact resistance is minimized, but the structure becomes more complex
Solution Approach 1:
The insert geometry is segmented into distinct functional surfaces: rake face, inclined planes, and abutting surfaces. Each segment serves a specific function - the rake face for chip flow, the inclined planes for dish formation, and the abutting surfaces for clamping. This segmentation allows complex dish geometry to be achieved through simple, well-defined surface intersections rather than complex curved surfaces.
Data Source
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AI summary
The present invention discloses a hexahedral insert having an opposed pair of top and bottom abutting faces an opposed pair of rake faces, and an opposed pair of side faces with a central hole passing through each central portion of the abutting faces, wherein arcuate corner portions with one-directional curvature are formed along the intersecting portions between the abutting faces and side faces; the central hole is substantially perpendicular to the abutting faces and parallel to the rake faces and side faces; the upper abutting face has a first wedge-shaped inclined plane adjoining and inclining toward a first rake face, the first wedge-shape having a base side at a cutting edge formed at the border to the first rake face and having a width starting at the border with a first corner portion and increasing gradually to a maximum at the border to a second corner portion and a second wedge-shaped inclined plane adjoining and inclining toward a second rake face, the second wedge-shape having a base side at a cutting edge formed at the border to the second rake face and having a width starting at the border with the second corner portion and increasing gradually to a maximum at the border to the first corner portion; and the second corner portion has a first inclined arcuate surface having continuity of gradient and width at the border to the first wedge-shaped inclined plane and the first corner portion has a second inclined arcuate surface having continuity of gradient and width at the border to the second wedge-shaped inclined plane, wherein the wedge-shaped inclined planes and the inclined arcuate surfaces are formed on the abutting faces and corner portions in top-and-bottom symmetricity such that the first rake face has a larger width on the side of the first corner portion whereas the second rake face has a larger width on the side of the second corner portion.