AU2012101783A4 - A drill rig - Google Patents

Abstract

A mobile drill rig wherein the penetration rate is determined by a hydraulic flow into or out of a transverse cylinder 0~22 o 24 - - --. 23 =13 o o 25

Description

P/00/012 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: "A DRILL RIG" The following statement is a full description of this invention, including the best method of performing it known to me/us: TITLE "A DRILL RIG" FIELD OF THE INVENTION This invention relates to a drill rig. In particular the invention 5 relates to a mobile drill rig that enables the penetration rate of the drill head to be accurately determined. BACKGROUND OF THE INVENTION Mobile drill rigs are used throughout the world for mineral exploration. The majority of mobile drill rigs include a traverse cylinder that 10 is connected to a rotation head through a rope and pulley system, chain and sprocket system or directly coupled. The rotation head is connected to the drill bit via a drill string. A hydraulic circuit controls the operation of the traverse cylinder. The hydraulic circuit includes a pull down pressure valve, hold back pressure valve and micro feed flow rate valve. The operation of 15 each of these valves determines to two features in drilling namely, the bit weight and the rate of penetration. One method of calculating the penetration rate is to directly measure the head travel distance with a stop watch. However this is time consuming and requires human input. The accuracy of this particular 20 method is also unsatisfactory. A further method of measuring penetration rate is to mark the pulley ropes to see how quickly they move past marks made on the mast to determine penetration rate. Again this is an extremely inaccurate method of measuring penetration rate. An alternative to the above methods which removes human 25 error is to fit linear transducers directly onto the transverse cylinder. Linear transducers are expensive to purchase and are difficult to maintain especially in extreme environments in which mobile drill rigs are used. Further, linear transducers do not provide a precise relative measurement for the purposes of controlling the-traverse cylinder. 30 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

2 OBJECT OF THE INVENTION It is an object of the invention to overcome and or alleviate one or more of the above disadvantages or to provide the consumer with a 5 useful and/or commercial choice. SUMMARY OF THE INVENTION In one form although not necessarily the only or broadest form the invention resides in a drill rig wherein the penetration rate is determined by a hydraulic flow into or out of a traverse cylinder. 10 In another form the invention resides in a mobile drill rig comprising: a hydraulic ram including a hydraulic piston and a hydraulic cylinder, the hydraulic ram operatively connected to a rotation head; a flow rate meter to measure the flow rate of hydraulic fluid 15 that is being fed into or out of the traverse hydraulic cylinder; and a visual display unit to display an output based on the measured flow rate of hydraulic fluid provided by the flow rate meter. The flow rate meter may be measure the amount of hydraulic fluid that flows from a rod end of the hydraulic cylinder. That is, where the 20 piston extends through the cylinder. The mobile drill rig may further include a diverter to protect the flow rate meter from an excessive flow rate of hydraulic fluid. In yet another form, the invention resides in a method of determining the penetration rate of a drill bit of a drill rig, the method 25 including the steps of: measuring the flow rate of hydraulic fluid being fed into or out of a transverse hydraulic cylinder; and transforming the amount of flow rate of the hydraulic fluid into a penetration rate. 30 The method may further include the step of displaying the penetration rate.

3 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of a mobile drill rig that includes a penetration rate measuring systems; Figure 2A is a hydraulic circuit diagram of a penetration rate 5 block in a closed position; Figure 2B is a hydraulic diagram of the penetration rate block of Figure 2A in an open position; Figure 2C is a hydraulic diagram of a penetration rate block of Figure 2B when the flow rate to the flow metre exceeds a predetermined 10 flow rate. PREFERED EMBODIMENT OF THE INVENTION Figure 1 shows a schematic representation of a mobile drill rig 10 which includes a penetration measuring system 100. The mobile drill rig 10 includes a hydraulic ram 11 which is 15 connected to a rope and pulley system 12 which both lowers and raises a rotation head 13. The rotation head 13 is connected to a drill bit 14 via drill string 15. The hydraulic ram 11 includes a hydraulic cylinder 16 and a hydraulic piston 17 which moves within the-hydraulic cylinder 16 due to the 20 flow of fluid into and out of the hydraulic cylinder 16. The hydraulic ram 11 is controlled by a hydraulic circuit 20 to reciprocate the hydraulic piston 17 within the hydraulic cylinder 16 to move the rotation head 13 up and down. A rod end of the hydraulic cylinder 16 is fluidly connected to a reservoir 21 via a hold back valve 22, the penetration rate measuring 25 system 100 and micro feed selector valve 23. The piston end of the hydraulic cylinder 16 is fluidly connected to the reservoir 21 via a micro feed rate valve 24, pull down valve 25 and micro feed selector valve 23. A pump 26 is able to pump hydraulic fluid to either end of the hydraulic cylinder 16 depending on the position of micro feed selector valve 23 which is 30 determined by a micro feed selector 27. Figure 1 shows the pump 26 supplying fluid to the piston end of the hydraulic cylinder 16.

4 The penetration rate measuring system 100 includes a penetration rate block switch 101, a penetration rate block 102, a flow meter 103, transducer 104 and visual display unit (VDU) 105. The penetration rate block 102 and flow meter 103 are located within the hydraulic circuit 20 5 between the hold back valve 22 and the micro selector valve 23. Accordingly, when hydraulic fluid is pumped from the reservoir 21 by the pump 26 via the pull down valve 25 and micro feed rate valve 24, this causes the hydraulic piston 17 to move upwardly causing hydraulic fluid to flow through the hold back valve 22, penetration rate block 102, flow meter 10 103 and back into the reservoir 21. The penetration rate block switch 101 is connected to the penetration rate block 101 to cause hydraulic fluid to flow through the flow meter 103. The flow meter 103 is connected to the transducer 104 which is then connected to the visual display unit 105. Accordingly, the flow of 15 hydraulic fluid out of the rod end of the cylinder 16 is measured by the flow rate meter 103. This measurement is subsequently transformed by the transducer into a penetration rate which is displayed on a visual display unit 105. It should be appreciated that the output from either the flow 20 rate meter or the transducer can be fed into a programmable logic controller, microprocessor or similar device to control the penetration rate given a drill rate set point. Accordingly it may be possible to automatically control the advancement of the hydraulic piston 17 within the transverse cylinder 16 automatically given specified parameters. 25 The operation of penetration rate block 102 is shown in more detail in Figures 2A, 2B, 2C. A hydraulic circuit 110 is shown which is representative of a hydraulic circuit located within the penetration rate block 102. The hydraulic circuit 110 includes an activation valve 111 to allow fluid to pass through the flow rate meter and a diverter valve 112 to protect the 30 flow rate meter from an excessive flow rate of hydraulic fluid. The hydraulic circuit also include two non-return valves 113 and 114 for normal protection purposes.

5 Figure 2A shows the hydraulic circuit 110 in which hydraulic fluid flow through the inlet, through the activation value 111 which is in an "off position" and through the outlet. That is, no fluid flows through the flow rate meter 103. 5 To enable to visual display unit to display the penetration rate, the activation valve is switched to an "on position" using the penetration rate switch 101 which causes hydraulic fluid to flow from the inlet through the activation valve 111 which then subsequently flows through the priority protection valve 113 and through the flow rate meter 103. The flow rate that 10 is passing through the flow rate meter is measure and subsequently transformed by the transducer 104 to be presented on the visual display unit 105. If the flow rate to the flow meter 103 is above a predetermined limit (which is typically above 6 liters per minute) this causes a back 15 pressure within the line that extends from the priority protection valve 112 to the flow rate meter 103. This back pressure causes the protection valve 112 to switch hydraulic fluid flow from flowing through the flow rate meter directly through the outlet which protects the flow rate meter 103 from being damaged. 20 In an alternative design to the hydraulic circuit 110, when the flow is large, priority protection valve 112 could be configured to allow hydraulic fluid to also flow to a second flow rate meter. The two flow rate measurements of the two flow rate meters could then be combined by the transducer 104 to provide a penetration rate through a full feed range if 25 required. Alternatively, for an application where less accuracy, is required a larger flow rate meter could be used. This case typically could be where the system is fitted to an RC drill rig which does rotary hammer holes only. 30 The penetration rate measuring system provides a low cost yet accuracy way in which the penetration rate of a drill bit on a mobile drill rig can be obtained. Further, the penetration rate measuring system could 6 be adapted to provide the feedback necessary for operation as part of an automated drilling system. In this specification, the terms "comprise", "comprises", "comprising" or similar terms are intended to mean a non-exclusive 5 inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed. It should be appreciate that various other changes and modifications may be made to the invention described without departing 10 from the spirit or scope of the invention.

Claims (5)

1. A mobile drill rig comprising: a hydraulic ram including a hydraulic piston and a hydraulic 5 cylinder, the hydraulic ram operatively connected to a rotation head; a flow rate meter to measure the flow rate of hydraulic fluid that is being fed into or out of the hydraulic cylinder; and a visual display unit to display an output based on the measured flow rate of hydraulic fluid provided by the flow rate meter. 10

2. The mobile drill rig of claim 1 in which the flow rate meter measure the flow rate of hydraulic fluid that flows from a rod end of the hydraulic cylinder.

3. The mobile drill rig of claim 1 or claim 2 further including a diverter to protect the flow rate meter from an excessive flow rate of hydraulic fluid. 15

4. A method of determining the penetration rate of a drill bit of a drill rig, the method including the steps of: measuring the flow rate of hydraulic fluid being fed into or out of a transverse hydraulic cylinder; and transforming the amount of flow rate of the hydraulic fluid into 20 a penetration rate.

5. The method of claim 4 further including the step of displaying the penetration rate.