| 摘要 |
The rotary rock drilling device comprises chiefly a body (1), a rotary cutting disc (2) and a counter-reaction member (3). The body (1), is fitted with means (101) for connection to a suitable rotary drive system, and it is traversed in the height direction by a conduit (102), (103) opening into orifices (104), (105), provided for the circulation of a drilling fluid. The cutting disc (2) is arranged on one side of the lower part of the body (1), the face of the disc (2) being orientated towards the concave bottom (501) and the cylindrical wall (502) of the hole (5). The counter-reaction member (3) is arranged on the side of the body (1) away from that carrying the cutting disc (2). The maximum radial projection from the axis of rotation (A) of the body (1) of any part of the counter-reaction member (3) is less than the radius of the hole (5). The surface of contact (301) between the counter-reaction member (3) and the hole (5) is situated below the line at which the concave bottom (501) of the hole (5) meets the cylindrical wall (502) of the hole (5). The lowest point (B) of the surface of contact (301), which closely matches the concave surface of the bottom (501) of the hole (4), is separated from the axis of rotation (A) by a distance (C) greater than the distance (D) from the lowest point (E) of the cutting disc (2) to the same axis (A). |
