Underground boring machine and method for controlling underground boring

Abstract

A method and system for controlling a horizontal directional drilling machine having a boring tool. A rate of rotation and a rate of thrust are selected by an operator. Controls allow an automatic boring operation mode to be initiated to maintain the selected rate of rotation and thrust without further input from the operator. Periodically, when the rotation and thrust are interrupted, such as to modify the drill string, the automatic boring operation mode is interrupted. The automatic boring operation mode may be resumed without requiring the operator to select the rate of rotation and rate of thrust. The rate of rotation is resumed before the rate of thrust to reduce drill string shock loads and increase drilling performance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows:

FIG. 1 illustrates a horizontal directional drilling machine;

FIG. 2 illustrates the operator control station of a horizontal directional drilling machine according to the principles of the present invention;

FIG. 3 illustrates a control lever of the operator control station of FIG. 2;

FIG. 4 illustrates a label identifying the function of the controls found on the control lever of FIG. 3;

FIG. 5 illustrates controls found on the right side of the operator control station of FIG. 2;

FIG. 6 illustrates a display according to the principles of the present invention;

FIG. 7 illustrates the rates of increase of rotational movement and axial thrust when a boring process is resumed; and

FIG. 8 is a flow diagram of a method of resuming automatic control of boring functions.

Claims

1. A method for controlling an underground boring tool as it passes through a formation, comprising: (i) setting a rate of rotation of the boring tool;(ii) setting an axial thrust of the boring tool;(iii) interrupting the set rates of rotation and axial thrust of the boring tool; and(iv) resuming the set rate of rotation of the boring tool before resuming the set axial thrust of the boring tool at a set rate.

2. The method of controlling an underground boring tool of claim 1, wherein the step of resuming the axial thrust of the boring tool comprises linear increases in the rate of axial thrust from zero to the set axial thrust.

3. The method of controlling an underground boring tool of claim 2, wherein the axial thrust is increased by about 25 percent of the set axial thrust per second for about three seconds followed by increasing the axial thrust by about 12.5 percent of the set axial thrust per second for about two seconds.

4. The method of controlling an underground boring tool of claim 1, wherein the steps are performed in order.

5. The method of claim 1, wherein the step of setting the rate of rotation of the boring tool comprises: (i) providing a controller that controls the rotation and axial thrust of the boring tool in response to control signals;(ii) providing a control device that produces a control signal to the controller that varies in proportion to a position of the control device;(iii) providing a control switch that produces a control signal to the controller to set the rate of rotation at the rate corresponding to the position of the control device;(iv) positioning the control device to a position that produces a control signal to the controller of the desired rate of rotation;(v) activating the control switch to produce a control signal to the controller that sets the rate of rotation to the rate set by the control device; and(vi) releasing the control device.

6. The method of claim 5, wherein the step of setting the rate of rotation of the boring tool further comprises: (i) providing a switch having a first position wherein a control signal is sent to the controller that increments the set rate of rotation and having a second position wherein a control signal is sent to the controller that decrements the set rate of rotation; and(ii) adjusting the set rate of rotation to a desired rate of rotation setting by moving said switch to the first or the second position.

7. The method of claim 1, wherein the step of setting the axial thrust of the boring tool comprises: (i) providing a controller that controls the rate of axial movement of the boring tool in response to control signals;(ii) providing a control device that produces a control signal to the controller that varies in proportion to a position of the control device;(iii) providing a control switch that produces a control signal to the controller to set the axial thrust force at the thrust force level that is present at the time the control switch is pressed as affected by the position of the control device and the formation;(iv) positioning the control device to a position that produces a control signal to the controller of the desired rate of axial movement;(v) activating the control switch to produce a control signal to the controller that sets the axial thrust to the force set by the control device; and(vi) releasing the control device.

8. The method of claim 7, wherein the step of setting the axial thrust of the boring tool further comprises: (i) providing a switch having a first position wherein a control signal is sent to the controller that increments the set axial thrust and having a second position wherein a control signal is sent to the controller that decrements the set axial thrust; and(ii) adjusting the set axial thrust to a desired axial thrust setting by moving said switch to the first or the second position.

9. The method of claim 1, wherein the step of resuming the set rate of rotation and thrust of the boring tool further includes: (i) providing a resume switch that produces a control signal to a controller that returns the rate of rotation and axial thrust of the boring tool to the set rate of rotation and set axial thrust; and(ii) activating the resume switch to return the rate of rotation and axial thrust of the boring tool to the set rate of rotation.

10. A system for controlling an underground boring tool, comprising: (i) a hydraulic system for imparting rotational motion and thrusting motion to a boring tool in response to rotational motion and thrusting motion control signals;(ii) controls for generating a rotational motion setting signal and a thrusting motion setting signal in response to the position of the controls;(iii) controls for generating an automatic boring mode signal;(iv) controls for generating an automatic boring mode cancel signal; and(v) a controller for receiving input signals including rotational motion and thrusting motion setting signals, automatic boring mode signals, and automatic boring mode cancel signals from the controls, for generating rotational motion and thrusting motion control signals in response to the input signals, and for communicating the motion control signals to operatively control the hydraulic system.

11. A system for controlling an underground boring tool, comprising: (a) a power system arranged and configured to impart rotational motion and a thrust motion to a boring tool in response to rotational motion and thrusting motion control signals;(b) a first operator actuated control, wherein a rotational motion setting signal is determined in response to the position of the first operator control;(c) a second operator actuated control, wherein a thrusting motion setting signal is determined in response to the position of the second operator control;(d) a third operator actuated control for generating a signal for incrementing and decrementing a rotational motion setting;(e) a fourth operator actuated control for generating a signal for incrementing and decrementing a thrust motion setting; and(f) a controller arranged and configured to receive receiving the signals from the first, second, third, and fourth operator actuated controls, for determining rotational motion and thrusting motion control signals in response to the signals, and for communicating the motion control signals to operatively control the power system.

12. The system for controlling an underground boring tool of claim 11, wherein the power system is hydraulic.

13. The system for controlling an underground boring tool of claim 12, wherein the hydraulic power system includes hydraulic pumps and hydraulic motors operatively connected thereto.

14. The system for controlling an underground boring tool of claim 13, wherein the hydraulic power system further includes a hydraulic fluid reservoir.

15. The system for controlling an underground boring tool of claim 11, wherein the first, second, third and fourth operator actuated controls are all located in physical proximity to one another.

16. The system for controlling an underground boring tool of claim 15, further comprising an operator console, and wherein the first, second, third and fourth operator actuated controls are located on the operator console.

17. The system for controlling an underground boring tool of claim 11, wherein the controller is arranged and configured to resume a set rate of rotation of the boring tool and then resume a set axial thrust of the boring tool at a set rate after an interruption of the set rates of rotation and axial thrust of the boring tool.

18. The system for controlling an underground boring tool of claim 17, wherein the controller resumes the axial thrust of the boring tool according to linear increases in the rate of axial thrust from zero to the set axial thrust.

19. The system for controlling an underground boring tool of claim 18, wherein the axial thrust is increased by about 25 percent of the set axial thrust per second for about three seconds followed by increasing the axial thrust by about 12.5 percent of the set axial thrust per second for about two seconds.

20. A method for controlling an underground boring tool as it passes through a formation comprising: (i) pumping fluid through a drill string to the boring tool;(ii) setting a rate of rotation of the boring tool;(iii) setting an axial thrust of the boring tool;(iv) stopping the fluid flow to the boring tool and stopping the rotation and axial thrust of the boring tool; and(v) resuming the fluid flow and set rate of rotation of the boring tool before resuming the set axial thrust of the boring tool at a set rate.