Method and an equipment for adjusting rock drilling

• US 5,458,207 A
• Filed: 10/13/1993
• Issued: 10/17/1995
• Est. Priority Date: 04/25/1991
• Status: Expired due to Term

• Current Assignee: Tamrock Oy (Sandvik AB)
• Original Assignee: Tamrock Oy (Sandvik AB)
• Inventors: Mattero, Unto
• Primary Examiner(s): MELIUS, TERRY L
• Application Number:
  US08/133,130
• Time in Patent Office: 734 Days
• Field of Search: 175/27, 175/26, 175/24, 175/40, 175/114, 73/151.5, 173/6
• US Class Current: 175/27
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions

Abstract

A method for optimizing rock drilling, wherein the drilling is adjusted by means of one or more adjustable parameters such as the feed rate and the rotation rate. In the method, a set value (H_s) of each adjustable parameter is deviated in accordance with a sinusoidal curve while integrating a change caused by the deviation in the penetration rate (x) and adding it to the set value (H_s) so that the set value (H_s) shifts closer to an optimum penetration rate (x_opt).

Claims

1. A method of optimizing rock drilling wherein a penetration rate of a drill bit of a drilling machine into a rock is measured and at least first and second operating parameters of a drilling equipment are adjusted to maximize the penetration rate, comprising the steps of:

causing a substantially continuous deviation to occur symmetrically on both sides of a set value of said first operating parameter to be adjusted, while maintaining said second parameter constant;

measuring a change in the penetration rate caused by said substantially continuous deviation on both sides of said set value of said first operating parameter to be adjusted; and

when the measured change caused by the deviation in the penetration rate is different on opposite sides of said set value of said first operating parameter, adjusting the set value of said first operating parameter on the basis of said measurement in a direction in which the penetration rate increases.

2. A method according to claim 1 including:

when a maximum value of the penetration rate is substantially achieved by adjusting said first operating parameter, causing a continuous deviation to occur symmetrically on both sides of a set value of said second operating parameter to be adjusted while maintaining said first parameter constant;

measuring a change in the penetration rate caused by the deviation of said second operating parameter; and

when the change caused by the deviation in the penetration rate of said second operating parameter is different on opposite sides of said set value thereof, adjusting the set value of said second operating parameter on the basis of said measurement in a direction in which the penetration rate increases.

3. A method according to claim 1 wherein the step of deviating includes deviating the set value of the first operating parameter as a sinusoidal curve.

4. A method according to claim 2 wherein the steps of deviating include deviating the set values of said first and second operating parameters as sinusoidal curves.

5. A method according to claim 2 wherein said first and second operating parameters to be adjusted are the feed force of the drilling machine and the rotation rate of the drill bit, respectively, said drilling machine including percussion machinery, and maintaining the percussion power of the percussion machinery substantially constant during said deviations.

6. A method according to claim 2 including providing a set value for each of said first and second operating parameters, combining with the set value of each parameter a deviation curve during adjustment of each parameter to deviate said set value, adding a change caused by the deviation in the penetration rate to the set value such that when the set value deviates from a maximum value of the penetration rate, the set value shifts automatically towards a set value corresponding to the maximum penetration rate, while maintaining the other operating parameter substantially constant.

7. Rock drilling apparatus for maximizing the rate of penetration of a drill bit into rock comprising:

control devices for providing set values of at least two operational parameters for the drilling apparatus;

means for measuring a penetration rate of the drill bit into the rock;

said control devices including automatically operated adjusting means for deviating one of said two parameters at a time from and on opposite sides of a set value; and

a measuring device to measure variation in the penetration rate resulting from a deviation of said one parameter on opposite sides of said set value;

said control device further including means for shifting the set value of said one parameter in response to the measured variation and in a direction in which the penetration rate increases;

said adjusting means being operable to change an operating parameter being deviated to another operating parameter to be deviated when the set value of the operating parameter being adjusted is adjusted to a value substantially corresponding to a maximum penetration rate of the drill bit.

8. Rock drilling apparatus according to claim 7 wherein said adjusting means comprises a first control means for sequentially deviating the set values for a feed force and a rotation rate of the drill bit.

9. Rock drilling apparatus according to claim 8 wherein said adjusting means comprises a second separate control means for adjusting the set value of both the feed force and the rotation rate, said penetration rate measuring means being arranged to control both said first and second control means, and said adjusting means further including a separate changeover control which alternately switches from one to another of said first and second control means into deviation operation for adjusting the respective set values.