| 摘要 |
PURPOSE: A drilling device is provided which allows a maintenance of an optimum adjustment of a maximum allowable torque over an entire operating range at the pressure surface without a technical complexity and preventing a head loss at the hydraulic circuit feeding a motor for driving a tool in rotation by the variable property of a head loss as a function of a temperature and hydraulic flow. CONSTITUTION: A drilling device comprises a drilling unit (1) the tool of which(2) is driven in rotation from a hydraulic motor (15) associated with an injection timing gear (8) for generating a pressure force of the drilling unit on the ground, the different actuating members (3, 8, 15) being driven by at least a hydraulic pump (10), through an assembly of hydraulic directional control valves (12, 13, 14) and an assembly of branches (16, 17, 18), such as flexible joints, the two branches (18) supplying the injection timing gear of the drilling system being equipped with a reverser (19) of the direction of the fluid in the injection timing device. On one of the branches of the supply circuit (17) of the hydraulic motor driving in rotation the tool is mounted a fluid measuring device (22, 37), permanently supplying information to a compensating device (23, 38, 39, 49) for subtracting the computed head loss generated by the assembly of the elements of the circuit between two known points of this circuit located on either side of the motor, from the difference of pressure measured between these same two points, the result of this operation actuating the reverser (19) of the direction of the working fluid, if the value exceeds a predetermined value.
|
