Percussion Drill Bit Convex Face Button Recess Spacing
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Solution Overview
Problem
Existing drill bits for percussion drilling face challenges in improving drilling performance and extending the life of the drill bit, particularly in maintaining button strength and preventing accidental removal during drilling.
Innovation Solution
The drill bit design features a front surface with a convex shape, comprising a first circular area, a second area extending at an angle α, and a third area extending at an angle β, with buttons arranged in circular recesses. This design increases the distance between button recesses, enhancing the drill bit's strength and preventing button loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If buttons are arranged in a flat face surface, then the manufacturing is simple, but the distance between recesses is reduced which weakens the drill bit strength and allows accidental button removal
Solution Approach 1:
The face surface is designed with a convex curvature instead of being flat. The first area has a first radius of curvature, the second area has a second radius of curvature, and the third area has a third radius of curvature, where the first radius is greater than the second radius which is greater than the third radius. This curved geometry increases the distance between recesses while maintaining structural integrity and preventing button removal.
2Productivity
If the number and radius of buttons are increased to improve drilling performance, then the drilling efficiency improves, but the drill bit strength is reduced due to more closely spaced recesses
Solution Approach 1:
The convex curved face surface with varying radii of curvature allows for increased number and radius of buttons while maintaining adequate spacing between recesses. The curvature distributes the buttons across a larger effective area, enabling higher productivity without compromising structural strength.
3Duration of action of stationary object
If buttons are arranged in a flat face, then the manufacturing precision requirement is low, but the button wear is uneven and drill bit life is reduced
Solution Approach 1:
The convex face surface with specifically designed varying radii of curvature (first radius > second radius > third radius) creates optimal button distribution and contact geometry. This curvature design promotes more uniform button wear patterns and extends drill bit operational life, while the radii ranges provide guidance for manufacturing precision.
Data Source
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AI summary
The present invention relates to a drill bit (100) for percussion drilling comprising: a drill bit body (101) intended to extend along an axis A and comprising a front surface (105), said front surface comprises a first circular area (110) arranged transverse and coaxially to axis A, a second area surface (111) surrounding said first area surface (110), said second area surface (111) is extending in an angle α in relation to a plane transverse to axis A, and a third area surface (112) surrounding said second area surface (111), said third area surface (112) is extending in an angle β in relation to a plane transverse to axis A such that the front surface (105) will have a substantially convex shape; and a number (n) of buttons (200) arranged in said second area surface (111) and third area surface (112), said buttons (200) have a button body (201) extending along an axis B and a length L along axis B, said button body (201) has a circular cross-sectional shape transverse to axis B, a rear end surface (203) and a forward end surface (204), wherein the angle α is within the range of 5 -15°, the angle β is within the range of 30 - 45° and the buttons 200 are arranged in circular recesses (120) extending substantially transverse from the second surface (111) and third area surface (112) into the drill bit body (101), said recesses (120) have a radius corresponding to the button body radius (Rb) and a depth corresponding to the length L of the button body (201) such that the button bodies (201) are fitted within the drill bit body (101) with the forward end surface (204) exposed in the second area surface (111) and third area surface (112).