| 摘要 |
Drilling device, of the type possessing a drilling unit of which the tool is driven to rotate from a hydraulic motor associated with an advancing device enabling a bearing force of the drilling unit on the ground to be created, the various actuating members being driven from at least one hydraulic pump via a set of hydraulic distributors and a set of tubes, such as hoses, the two feed tubes of the advancing device of the drilling system being equipped with a switch for reversing the direction of circulation of the fluid in the advancing device. Mounted on one of the branches of the feed circuit of the hydraulic motor for driving the tool in rotation is a fluid measurement device constantly supplying information to a compensation device for subtracting the calculated loss of head created by all the members of the circuit between two known points in that circuit, situated on either side of the motor, from the pressure difference measured between those same two points, the result of this operation actuating the switch for reversing the direction of circulation of the advancing fluid if the value exceeds a given value. |
