Down-the-hole Drill Bit Protrusions for Soil Penetration
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Solution Overview
Problem
Conventional down-the-hole drilling devices are inefficient in drilling various soil types, particularly hard clay and sand, due to their rock drill bit design, which leads to slow penetration and potential breakage, and also experience jamming and vibration issues in boulders and moraine formations due to the long distance between cutting inserts.
Innovation Solution
The addition of narrow protrusions at the trailing edges of the flushing channel grooves on the pilot drill bit surface enhances cutting efficiency, allowing for effective soil penetration and flushing, even with smaller grooves, and can be easily integrated into existing drill bit manufacturing processes without significant modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rock drill bit design with a large and flat drilling surface is used, then the drill bit is suitable for drilling rock, but the impact energy reflects backwards and breaks the drill bit when drilling hard clay and sand, and penetration is slow
Solution Approach 1:
The drill bit surface is divided into different zones with distinct functions: the pilot portion has a conical shape with cutting inserts for penetrating hard clay and sand, while the reamer portion has a cylindrical shape with cutting edges for reaming the hole. This local differentiation allows each zone to be optimized for its specific function, improving both adaptability and reliability.
Solution Approach 2:
The drill bit is segmented into two main components: a pilot drill bit for initial penetration and a reamer for hole enlargement. The pilot can be detached and removed after drilling, allowing the reamer to complete the hole. This segmentation enables the system to handle different soil types effectively while maintaining durability through specialized design of each segment.
2Productivity
If the depth of flushing grooves on the drilling surface is increased to improve clay and sand drilling efficiency, then drilling performance in clay and sand improves, but jamming and vibration issues occur in boulders and moraine formations
Solution Approach 1:
The flushing grooves are positioned specifically on the pilot drill bit surface in zones optimized for clay and sand removal. The grooves have varying depths and orientations in different areas, with deeper grooves in regions where clay and sand accumulation is most problematic, while maintaining shallower features in areas prone to boulder jamming.
Solution Approach 2:
The drill bit system allows for dynamic adjustment of drilling parameters and can switch between different drilling modes. The pilot drill bit with optimized groove configuration handles clay and sand formations, while the reamer with its own cutting pattern handles boulders and moraine, providing adaptive response to different ground conditions.
3Ease of manufacture
If the distance between cutting inserts is increased to reduce manufacturing complexity, then manufacturing becomes simpler, but jamming and vibration issues occur in boulders and moraine formations
Solution Approach 1:
Cutting inserts are strategically positioned with different spacing patterns in different zones of the drill bit. The pilot portion has closely spaced cutting inserts to prevent jamming in boulders and moraine, while the reamer portion has spacing optimized for its reaming function. This localized optimization maintains manufacturing simplicity while ensuring reliability across different formations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient drilling across different soil types with reduced manufacturing costs, faster hole completion, lower fuel consumption, and decreased CO2 emissions, eliminating the need for multiple drill bits for varying ground conditions.
Implementation Method 1
a flushing flow arrangement (6) for feeding of a pressurized flushing medium onto a drilling surface P of the drilling arrangement by a feed flow arrangement (6a) and for discharging the same from the drilling surface together with drilling waste backwards with respect to the drilling direction by an exhaust flow arrangement (6b)
Implementation Method 2
The drilling surfaces P1, P2 of the first and second drilling means 4, 5 are provided with cutting inserts 10a submerged therein
Implementation Method 3
A consequence of the above is that the penetration is slow, and the echoing impact energy has the tendency to break the drill bit
Data Source
Figure 1a~1b
Figure 2
Figure 3a~3d
AI summary
The invention relates to a down-the-hole drilling device (1) for drilling to be performed with a casing pipe, wherein the drilling device comprises in its drilling head: a drilling arrangement having first drilling means for drilling a center hole and second drilling means for reaming the center hole for the casing pipe; and a flushing flow arrangement for feeding of a pressurized flushing medium onto a drilling surface of the drilling arrangement by a feed flow arrangement that is arranged to lead the flushing medium for drilling onto the drilling surface (P1) of the first drilling means at a flushing channel assembly (6a1) therein in essentially radial direction. The drilling surfaces of the first and second drilling means are provided with cutting inserts (10a) submerged therein. The drilling surface (P1) of the first drilling means comprises a protrusion assembly (PT) in order to enhance drilling efficiency and to guide drilling waste at the flushing channel assembly (6a1).