FIELD OF THE INVENTION

This invention relates to rock drill testing. In particular, the invention relates to a rock drill test device.

BACKGROUND OF THE INVENTION

The inventor is aware of pneumatic and hydraulic rock drills used in mines. However, there is no method of testing the functional operation of such rock drills.

It is an object of the invention to provide a device for testing all operational characteristics of a rock drill.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, there is provided a rock drill test device, which includes

a mechanical rig onto which a rock drill can be mounted;

a sensor pack, which contains sensors to test operational parameters of the rock drill to be mounted onto the mechanical rig; and

a processor module connected to the sensor pack, operable to read inputs from the sensor pack and to compare the operational parameters from the rock drill with acceptable operational parameters for the rock drill.

The term rock drill in this specification can refer to a handheld rock drill used in mining applications and to a rock drill component that is mountable on a rock drill rig.

The mechanical rig may include an acoustic noise and oil mist chamber into which the rock drill can be mounted, operable to reduce acoustic noise and contain oil mist when the rock drill is tested to reduce health risks such as hearing damage and oil mist inhalation. The sensor pack may include any one or more of the following sensors:

• a rotational speed sensor for measuring the rotation speed of the rock drill chuck and/or the drill steel;

• a torque sensor to measure the torque applied onto the drill by a brake mechanism

• a pressure sensor for measuring a driving fluid pressure in a feed line of the rock drill;

• a thrust/pressure sensor for measuring thrust exerted onto the rock drill

• an impact sensor for measuring the impact force exerted by the rock drill;

• a percussion rate sensor measuring the percussion rate of the rock drill

• a flow sensor for measuring the flow rate of a driving fluid in a feed line of the rock drill;

• an acoustic noise sensor measuring sound pressure level of the rock drill, calculated by a special formula for enclosed sound pressure level measurements; and

• a temperature sensor for measuring temperature of a rock drill casing, air exit or air inlet to or from the rock drill.

The processor module may include signal conditioning circuitry the inputs of which are connected to the respective sensors, the signal conditioning circuitry operable to adjust the electronic signal values which are to be read by any one of a digital and an analogue input of a data acquisition module, the data acquisition module connected to outputs of the signal conditioning circuitry.

The processor module may contain algorithms and formulas to do data processing to record and note any one or more of the following: rate of penetration of the drill under test; hammering power; acoustic pressure level; speed and torque relationships; impact force and percussion rate relationships; thrust-speed; thrust-torque; thrust-impact; thrust-percussion rate and trust penetration rate relationships.

The processor module may include a data capturing computer, operable to read inputs from the data acquisition module. The data capturing computer may host a database of the acceptable operational parameters The rock drill test device may include an incremental brake mechanism to incrementally exert a braking force and torque onto the drill rotation.

The rock drill device may include an incremental thrust mechanism to incrementally exert a thrust force onto the rock drill or rock drill steel which will increase or decrease impact force.

The rock drill test device may include an operator console, operable to receive inputs from an operator and to display outputs to the operator. The operator console may be operable to monitor and control the test device in an automated way from the inputs from the operator by controlling the flow of driving fluid to the drill through pneumatic, servo or solenoid valve technology. The test device may include a lubrication system, operable to apply lubricant to the drill through automated controlling of lubricant through pneumatic, servo or solenoid valve technology. The test device may be controlled by a servo motor and a stepper motor to increase or decrease the braking torque and thrust force. Data is captured automatically through software control of the processor module, the data acquisition module and data storing capability on hard disk as well as a Structured Query language (SQL) database.

The rock drill test device may contain an equipment number scanner being any one of a barcode, an RFID, a NFC transceiver, an optical communication device, wireless technology such as Bluetooth, LORA, Wi-Fi, Li-Fi or any other communication technology. The equipment number scanner may be operable to interface with an active- or passive identity module mounted on a rock drill.

The rock drill test device may contain a data scanning device to transfer any data captured onto the rock drill during operation from the rock drill onto the test device.

The rock drill test device may be connectable to a remote database, such as a Structured Query language (SQL) database, or the like. The rock drill test device may include switchgear, connectable to an output of the data acquisition module, the switchgear operable to control inputs to the mechanical rig. The brake torque, the impact thrust, the lubricant flow, the flow of the driving fluid, the electrical power, warnings to the operator, drill cleaning and flushing, acoustic chamber and drill covers may be controlled by switchgear from the test device. The switchgear may include a relay interface.

In use, the rock drill test device may test a rotational speed in the range of 0 rpm to 1000 rpm by means of any one of an the optical, magnetic, induction and reflective speed sensor.

In use, the rock drill test device may test a rotational torque in the range of 0 Nm to 500 Nm rpm by means of load cells or torque sensor.

In use, the rock drill test device may test an impact force in the range of 0 g.msec to 400 g.msec by means of an impulse sensor, accelerometer, or force sensor.

In use, the rock drill test device may test an impact frequency in the range of 0 Hz to 200 Hz by means of an impulse sensor, accelerometer, force sensor or acoustic sensor.

In use, the rock drill test device may test a drill noise sound pressure in the range of 80 dB to 120 dB by means of an acoustic sensor; a microphone or a sound pressure level meter.

The invention extends to a method of testing a rock drill test device, the method including

installing a rock drill onto a mechanical rig;

activating a rock drill;

reading inputs from a sensor pack, the inputs representing operational parameters of the rock drill;

comparing the operational parameters of the rock drill with acceptable operational parameters for the rock drill; and generating an acceptance test report on which the measured operational parameters are compared with the acceptable operational parameters.

Generating an acceptance test report may include providing a print-out of the acceptance test report.

The invention is now described, by way of non-limiting examples, with reference to the accompanying figures:

FIGURE(S)

In the figure(s):

Figure 1 shows a functional block diagram of a rock drill test device in accordance with one aspect of the invention; and

Figure 2 shows a print-out of an acceptance test report generated by the rock drill test device of Figure 1 .

In the figures, like reference numerals denote like part of the invention unless otherwise indicated.

EMBODIMENT OF THE INVENTION

Figure 1 shows a functional block diagram of a rock drill test device (10) in accordance with the invention.

The rock drill test device (10) includes a mechanical rig (12) onto which a rock drill (not shown) can be mounted, a sensor pack (14), which contains sensors to test operational parameters of the rock drill to be mounted onto the mechanical rig (12). The sensor pack (14) include a rotational speed sensor (14.1 ) for measuring the rotation speed of the rock drill chuck and or drill steel (jomper), a pressure sensor (14.2) for measuring a driving fluid pressure in a feed line of the rock drill, an impact sensor (14.3) for measuring the impact force exerted by a rock drill and a flow sensor (14.4) for measuring the flow rate of a driving fluid in a feed line of the rock drill. The rock drill test device (10) further includes a processor module (16) connected to the sensor pack (14), operable to read inputs from the sensor pack and to compare the operational parameters from the rock drill with acceptable operational parameters for the rock drill.

The processor module (16) includes signal conditioning circuitry (16.1 ) the inputs of which are connected to the respective sensors, the signal conditioning circuitry adjusting the electronic signal values to be read by any one of a digital and an analogue input of a data acquisition module (16.2), the data acquisition module (16.2) connected to outputs of the signal conditioning circuitry.

The signal conditioning circuitry includes a conditioning circuit (16.1.1 ) for the speed sensor (14.1 ), a conditioning circuit (16.1.2) for the pressure sensor (14.2), a conditioning circuit (16.1 .3) for the impact force sensor (14.3) and a conditioning circuit (16.1.4) for the flow sensor (14.4).

Not shown on the block diagram is an acoustic noise chamber and oil mist chamber into which the rock drill can be mounted, operable to reduce acoustic noise when the rock drill is tested.

The processor module (16) includes a data capturing computer (16.3), operable to read inputs from the data acquisition module (16.2). The data capturing computer (16.3) hosts a database of acceptable operational parameters.

The rock drill test device (10) further includes an operator console (18), operable to receive inputs from an operator and to display outputs to an operator.

The rock drill test device is connectable to a remote database (20), such as a Structured Query Language (SQL) database, or the like.

The rock drill test device (10) includes switchgear in the form of a relay interface (22), connectable to an output of the data acquisition module (16.2), the switchgear operable to control inputs to the mechanical rig, such as the brake torque, the impact thrust, the lubricant flow, the driving fluid flow, the electrical power, warnings to the operator; drill cleaning and flushing, acoustic chamber and drill covers are controlled by switchgear from the test device.

In use, the rock drill test device can test a rotational speed in the range of 0 rpm to 1000 rpm by means of any one of an the optical, magnetic, induction and reflective speed sensor, a rotational torque in the range of 0 Nm to 500 Nm rpm by means of load cells or torque sensor, an impact force in the range of 0 g.msec to 400 g.msec by means of an impulse sensor, accelerometer, or force sensor, an impact frequency in the range of 0 Hz to 200 Hz by means of an impulse sensor, accelerometer, force sensor or acoustic sensor, and a drill noise sound pressure in the range of 80 dB to 120 dB by means of an acoustic sensor; a microphone or a sound pressure level meter.

In use, the rock drill test device (10) implements a method of testing a rock drill test device, which includes installing a rock drill (not shown) onto a mechanical rig (12), activating a rock drill in the mechanical rig (12), reading inputs from the sensor pack (14), the inputs representing operational parameters of the rock drill, comparing the operational parameters of the rock drill with acceptable operational parameters for the rock drill and generating an acceptance test report on which the measured operational parameters are compared with the acceptable operational parameters. The rock drill test device implements a method of downloading data from the rock drill, which captured drill operational data during underground operation.

The step of generating an acceptance test report includes providing a print- out of the acceptance test report.

Figure 2 shows a print-out (30) of the acceptance test report.

In the report, an operator name is printed at (32), a rock drill number at (34), the type of test performed at (36) and the date at (38).

The report may contain data as captured and transferred from the rock drill, as well as display a time stamped or non-time stamped total operation drilling hours, on- collar and off-collar operational hours, number of holes drilled, drilling angles of each hole, shafts, sections, stopes and panels at which have been drilled as identified by a unique drill operator identification number.

A graph, showing various torque/speed curves is printed at (40).

An indication that the drill has passed is done at (54) or that it failed at (56).

A graph showing impact force over time is printed at (42). A calculated rate of penetration is shown at (44), as is shown at (46) and a drill Sound Pressure level (SPL) is shown at (48).

Sound Pressure or acoustic pressure is the local pressure deviation from the ambient (average, or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured by use of a microphone, and in water by use of a hydrophone. The SI unit of sound pressure is the pascal (Pa).

Sound pressure level (SPL) or acoustic pressure level is a logarithmic measure of the effective pressure of a sound relative to a reference value. Sound pressure level denoted Lp and measured in dB, is defined by

Where

• p is the root mean square sound pressure;

• po is the reference sound pressure ;

• 1 Np is the neper;

• 1 B = (1/2 In 10) Np is the bel;

• 1 dB = (1/20 In 10) Np is the decibel.

The commonly used reference sound pressure in air is

Po = 20 mRa

which is often considered as the threshold of human hearing (roughly the sound of a mosquito flying 3 m away). The proper notations for sound pressure level using this reference are L _P /(20 mRά) or L _P { re 20 mRά) , but the suffix notations dB SPL, dB(SPL), dBSPL, or dBSPL are very common, even if they are not accepted by the SI.

The test operator signs the acceptance test certificate at (50) and dates it at (52).

The rock drill can be tested at a full dynamic range regarding rotational speed and torque as well as impact force and percussion rate which indicate penetration rate. Advantageously, use of an acoustic noise chamber will reduce prolonged noise exposure to the test operators. Oil fumes/vapour will be contained in the enclosed drill rig to minimise inhaling by the operators while testing. Acceptance test data will be captured, stored and printed as proof of rock drill refurbished performance. An acceptance test performance baseline can be obtained from the data to establish how many drills failed, how many drills passed and which operator tested/refurbished the drill. Drill and fleet of drills reliability-, maintainability-as well as drill performance data can be obtained from the stored data. A representative air supply provides a similar interface to the drill and represents the underground drilling condition. Drills can be sent back to the shafts with confidence and proof of their performance against a fixed performance, maintenance and reliability baseline.

The invention provides a new rock drill test device and a new method of testing a rock drill, which does not exist to date. Use of the rock drill test device will ensure that each rock drill is tested against a known standard for compliance with standards, before the rock drill is deployed. This will lead to improved operation time and will reduce workshop repair costs.