Tangential Circular Saw Blade Geometry for More Resharpening
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Solution Overview
Problem
Conventional circular saw blades face limitations in the number of resharpening intervals due to the tangential alignment of cutting parts, leading to decreased clearance angles and increased friction, which can result in tool or workpiece damage, and require complex repositioning for effective sharpening.
Innovation Solution
The circular saw blade design features a cutting piece with a first angle of 50° to 90° and a second angle of 30° to 80°, where the radial length of the cutting piece is greater than its tangential length, allowing for increased resharpening without altering the utility properties and maintaining a stable tooth thickness by reversing the sharpening ratio, enabling up to three times more removal on the rake face than the flank.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the cutting piece is aligned essentially tangentially to increase the resharpening zone on the rake face, then the resharpening capacity is improved, but the clearance angle decreases with each sharpening process which increases friction on the flank face
Solution Approach 1:
The cutting piece is divided into functionally distinct surfaces: a rake face for material removal and flank faces (first and second) with different angular relationships to the rake face. This segmentation allows independent optimization of each surface's function, enabling the rake face to be resharpened multiple times while the flank faces maintain appropriate clearance angles.
Solution Approach 2:
The first flank face is positioned at a first angle to the rake face while the second flank face is positioned at a second angle, creating an asymmetric configuration. This asymmetry ensures that as the rake face is resharpened and its geometry changes, the flank faces maintain different angular relationships that prevent both surfaces from simultaneously developing excessive friction or interference.
2Duration of action of moving object
If the cutting piece is aligned essentially tangentially to allow increased resharpening on the rake face, then the service life is extended, but the rear end of the flank may strike the workpiece causing noise and damage
Solution Approach 1:
The geometry of the cutting piece is pre-configured with specific angular relationships between the rake face and both flank faces before any resharpening occurs. This preliminary geometric design ensures that even after multiple resharpening operations reduce the rake face dimensions, the flank faces are positioned at angles that prevent them from striking the workpiece, thereby eliminating noise and damage issues before they can occur.
3Device complexity
If only the rake face is resharpened to simplify the sharpening process, then the sharpening complexity is reduced, but the clearance angle decreases which increases friction
Solution Approach 1:
The cutting piece geometry is segmented into a rake face designed for resharpening and separate flank faces with built-in clearance angles. This segmentation allows the sharpening process to focus exclusively on the rake face without needing to address the flank faces, simplifying the process while the separate flank geometry inherently maintains appropriate clearance angles to prevent friction increase.
4Shape
If the cutting piece has equal radial and tangential lengths for balanced geometry, then the structural symmetry is improved, but the resharpening capacity is limited by the shorter dimension
Solution Approach 1:
The cutting piece employs asymmetric dimensions where the radial length and tangential length differ, with the larger dimension oriented in the direction that maximizes resharpening capacity. This asymmetric geometry allows the cutting piece to accommodate more material removal cycles on the rake face before reaching the limit of usable geometry, thereby increasing the number of resharpening intervals while maintaining functional effectiveness.
Data Source
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AI summary
A circular saw blade with a support body (1) and a plurality of recesses (1.0) provided in its circumference, which form a seat surface (1.1) and a back surface (1.2) and into which a cutting element (2) with a rake surface (2.3) pointing in the direction of rotation (D) and a clearance surface (2.1) pointing radially outwards is inserted, wherein the clearance surface (2.1) extends at a first angle (β) to the rake surface (2.3), and the cutting element (2) has a second clearance surface (2.2) which extends at a second angle (β') to the rake surface (2.3), wherein the first angle (β) is greater than the second angle (β'), is characterized in that the first length (b) of the cutting element (2) projected in the tangential direction (T) is greater than its second length (a) projected in the radial direction (R), and that the first angle (β) in the region of 50° to 90° and the second angle (β') is in the range of 30° to 80°.