Rock Step Drill Inserts for Wear Resistance and Dust Extraction
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Solution Overview
Problem
Existing step drills used for drilling in concrete or reinforced concrete experience high wear on their cutting edges, leading to reduced service life and efficiency, particularly when used with hammer, impact, and rotary drilling devices.
Innovation Solution
The use of separate cutting inserts for both the pre-drilling and drilling stages, arranged on a base body surrounding the drill head, allows for the incorporation of harder materials, reducing wear and enabling cost-effective production while improving drilling speed and service life. Additionally, the suction channel arrangement is optimized to internal suction, minimizing drilling dust and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the cutting edges are made from the main body material of the step drill, then the manufacturing is simpler and more cost-effective, but the wear resistance is insufficient and service life is reduced
Solution Approach 1:
The cutting edges are segmented from the main body and implemented as separate replaceable inserts. This allows the cutting inserts to be made from hard, wear-resistant materials while the main body can be made from more ductile, easier-to-manufacture materials. The cutting inserts are mounted in receptacles on the base body, enabling independent material optimization for each component.
2Reliability
If harder materials are used for the cutting edges, then wear resistance and service life are improved, but manufacturing complexity and cost increase
Solution Approach 1:
By separating the cutting edges into independent inserts, the patent enables the use of harder, more wear-resistant materials specifically where needed, without requiring the entire drill to be made from such materials. This segmented approach localizes the complexity to only the cutting inserts while keeping the main body simple.
Solution Approach 2:
The cutting inserts are designed to be replaceable rather than permanent. When the cutting inserts wear out, they can be discarded and replaced with new ones, extending the overall service life of the drill tool. This allows the main body to remain in use for extended periods while only the consumable inserts are replaced.
3Device complexity
If drilling dust is discharged through external helical flutes, then the structure is simpler, but dust extraction efficiency is reduced and environmental impact increases
Solution Approach 1:
The extraction channels are nested within the interior of the drill shaft, with extraction openings positioned on the outer circumference. This internal channel arrangement allows dust to be evacuated through the drill structure itself rather than requiring external flutes, containing the dust flow path within the drill geometry and improving extraction efficiency.
Data Source
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AI summary
The invention relates to a step drill, in particular a rock step drill, with a drill shaft (2) having a shank (3) and a drill head (4) arranged at the end of the drill shaft (2) facing away from the shank (3), wherein the drill head (4) has a pre-drilling stage (5) for drilling a borehole with a first diameter and at least one enlargement stage (6) for widening a borehole drilled with the pre-drilling stage (5) to a larger diameter, wherein the enlargement stage (6) is arranged offset from the pre-drilling stage (5) along a longitudinal axis (B) of the drill, wherein the step drill (1) has at least one extraction channel arrangement (7) with at least one extraction channel (8) which leads from at least one extraction opening (9, 9a, 9b) of the drill head (4) through the interior of the drill shaft (2) to an outlet opening (10) for conveying drilling dust to a suction device (11).It is proposed that a cutting edge (12) of the pre-drilling stage (5) is formed by at least one cutting insert (13), that a cutting edge (14) of the reaming stage (6) is formed by at least one separate cutting insert (15), and that the cutting inserts (13, 15) are arranged on a base body (16) encompassing the drill head (4).