Technical Information技術的な案内
How material, water, speed and pressure change drilling speed and bit life.
Harder materials are less abrasive. They are cut into fine particles that don't wear the segment, so new diamonds aren't exposed: coring slows and bit life goes up.
Softer materials are ripped apart by the diamonds. The coarse cuttings get through quicker but shorten bit life.
Small pieces take less time to core through, but the aggregate chips into sharp edges and the segment drops diamonds.
Large aggregate takes longer to core, but the finer cuttings cause less segment wear.
Abrasion wears the segment and exposes more diamonds, which may fall out before they wear out.
Less abrasion slows segment wear and exposes fewer new diamonds: the bit lasts longer but cuts slower.
Steel is tough and dense compared with concrete and wears a bit quickly. Less steel means better cutting.
To cut heavy reinforcement, increase pressure or rpm, or reduce water flow or add sharp silica sand. All of these reduce bit life.
A harder bond slows the controlled erosion that exposes new diamonds.
Faster bond erosion shortens bit life: diamonds fall out before they wear out.
Cuttings stay in the hole and expose more diamonds: faster coring, shorter life.
Too much water slows segment erosion and may lead to bit glazing.
Slurry is not cleared, exposing new diamond edges that cut fast and wear fast. Diamonds stay in contact with the concrete longer.
Above the recommended rpm the segment glazes and contact time drops, so cutting slows.
Low pressure lets the bit glaze. Bit life goes up, performance goes down.
High pressure exposes new cutting edges, but diamonds may fall out early. Excessive pressure can collapse the crown.
Source: Shibuya Overview Catalogue, Technical Information.
