Method for steering a mining machine cutter

Description of the invention

Background of the invention

[0001] This disclosure relates to a method of controlling a mining machine cutter, the mining machine being of the type having a body adapted to move along the face of the mineral to be mined, the body having at each end a pivot arm pivotally mounted on the body, each the arm supports the rotating cutting drum. Such a machine is known as a double-sided pivoting drum cutter.

[0002] Many means are known for notching and extracting the desired mineral, but one commonly used form, especially for coal extraction, is the use of a tilt drum machine having pivot arms at each end, the cutting drum having a plurality of cutting posts being rotated. at the end of each pivot arm which is pivotally attached to the machine body. The machine body is moved along the surface and each rotating drum cleaves material from the surface.

[0003] Such a machine is controlled so as to allow the drum to always bite into the mine surface by adjusting the pivoting control of the swing arms. Skilled operators who observe the drum and deck operations can do this manually, but automatic means may also be used as dust formation and water spraying can impair the visibility of the drum to operators.

[0004] Such a machine carries a number of sensors mounted on the machine, the sensors being adapted to measure various parameters of the mining operation and to generate electrical signals representing said parameters. For example, some sensors may be adapted to take measurements along a surface, pitch, or roll. roll) by the machine, other sensors may be adapted to measure the displacement and direction of the machine, and still other sensors may be adapted to measure the positions of the front and rear pivot arms relative to the machine. When controlling a cutting machine, it is important to ensure that the machine will not wander into layers on either side of the mining deck surface. In order to ensure this, it is normal to leave a few inches of workpiece to form the roof and the subsoil such that any slight variation in the path of the cutting machine only changes the thickness of the roof and the subsoil and does not scrape adjacent layers.

[0005] The walkway ends of the longwall surface are typically taller above the excavation substrate than the remainder of the excavation surface because the conveyor bed must climb the conveyor drives at the walkway ends.

-2 working surface. This causes the cutter to rise at the ends of the pavement. As a result, the cutter operator has to rotate the swing arm lower at the ends of the walkway to continue to effectively extract the coal from the excavation surface.

[0006] A problem may arise when the operator leaves the swing arm in the lowered position and also tries to exit the walkway end area. If this is the case, then the swing arm is below the undercut and the cutting machine may bite into the excavation bed, possibly damaging the machine.

[0007] US 4822105 A discloses a two-sided pivoting cutter with a cutter body, a pair of drums and detectors for detecting the displacement position of the cutter body and the inclination of the cutter body in the displacement position and the height of the drums in the displaced position. US 4822105 A thus discloses a method of controlling a mining machine which comprises a body adapted to translate along a machined surface of the mineral, the body having at each end a pivot arm pivotally mounted on the body, and each arm supporting a rotating cutting drum; a plurality of sensors mounted on the machine and adapted to measure various parameters of the cutting operation and to generate signals representative of said parameters, the first of said sensors being adapted to measure the positions of each of said arms relative to the machine, the second of said sensors being adapted to measure the displacement and the direction of the machine, the method comprising the steps of: determining, on the basis of sensors, indicating the position of the pivot arm relative to the excavation ground, and determining the current position of at least one pivot arm.

The essence of the invention

[0008] It is an object of the present disclosure to provide an improved method of controlling the rear drum of a mining machine to assist in limiting the likelihood of undercutting by the material operator below the mine surface.

[0009] It is also an object of the present disclosure to limit the amount of undercutting at a location other than at the ends (referred to as a walkway, such as the front end of the walkway and the rear end of the walkway) of the face, hereinafter referred to as the face path, while simultaneously allowing full undercutting at the pavement ends. These objectives are achieved by a method for controlling a mining machine according to claim 1. The control system monitors the angle of each swing arm relative to the main frame of the machine. While the machine is in the defined area along the face, if the arm angle is changed by the operator to a lower value than defined by the parameter, the set point is referred to as the undercutting limit, the control system does not allow the arm to further lower. When entering the face path from either end of the pavement, if any of the swing arms are below a predetermined point, the cutter will stop moving horizontally and a beacon will flash to warn the operator that he must raise the arm before the cutter can be allowed to move horizontally .

The machine includes a tilt arm inclinometer, a tilt and lateral tilt sensor, and transmission sensors.

Brief description of the figures of the drawing

[0011]

Fig. 1 is a perspective view of a cutting machine known as a longwall cutter illustrated as it moves along an armored face conveyor.

Fig. 2 is a perspective view of the cutter shown in Fig. 1, with arrows indicating the lateral tilt and tilt of the machine as well as the position of the pivot arm relative to the machine.

Fig. 3 is a schematic illustration of the face of the wall face.

Fig. 4 is a diagram illustrating an anti-undercutting program 64.

Fig. 5 is a schematic diagram of the face end process 70 shown in Fig. 4.

Fig. 6 is a diagram of the drag process 76 for the swivel angle shown in Fig. 5.

Fig. 7 is a schematic diagram of the tractor drag blocking process 78 shown in Fig. 5.

Fig. 8 is a schematic diagram of a process 73 for limiting the deflection of the left boom shown in Fig. 7.

Fig. 9 is a schematic diagram of a process 74 for limiting the deflection of the right boom shown in Fig. 7.

[0012] Before one embodiment of the disclosure is described in detail, it should be understood that this disclosure is not limited to its application to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or carried out in various ways. It should also be understood that the phraseology and terminology used in this document are intended to be descriptive and should not be considered limiting. The use of the terms "including" and "comprising" as well as their inflected forms in this document is intended to include the elements listed thereafter and their equivalents as well as additional elements. The use of the term "consisting of" and variants thereof is intended to cover only the element listed thereafter and their equivalents. Moreover, it should be understood that terms such as "forward", "backward", "left", "right", "up", "down" etc. are for convenience and should not be interpreted as limiting.

Description of the preferred embodiment

[0013] Fig. 1 illustrates one type of coal mining apparatus 11 comprising a movable mining or cutting machine in the form of a cutter 26 that has a rotating cutter or mining head 34 provided with a plurality of cutters 38

-4 adapted to move coal away from seam (not shown). The cutter 34 is attached to a movable boom system 42 which allows the position of the cutter 34 to be adjusted relative to the mine floor. As the cutter 34 is rotated and moved forward into the seam, the coal is displaced from the face of the excavation and is collected on the collecting and conveying apparatus 36 of the coal mining apparatus 11. The conveyor apparatus 36 discharges the cut material into a separate free-standing or mobile conveyor apparatus (not shown) for final discharge from the mine. The front cutter 34 cuts the top of the seam and the rear cutter extracts the debris. The cutting machine is dragged along the armored conveyor in the conventional manner as it processes the material.

[0014] In some instances, an operator (not shown) manually moves the cutter along the surface of the excavation 60 (see Fig. 3) and also controls the position of the swing arms 42. The operator interacts with the machine by ensuring that the operator input signals to the machine or system controller control 52. The machine controller 52, in conjunction with the anti-undercut protection program 64 (see Fig. 4), it then causes horizontal displacement of the machine (dragging) and displacement of the pivot arm.

[0015] In order to limit damage to the cutting machine 26, this disclosure provides a method of limiting accidental contact of the mining head 34 with the excavation substrate or other parts of the longwall system (not shown). This method is implemented by software in the machine controller 52 and uses the operating diagrams shown in Figs. 4 to 9.

[0016] In summary, anti-undercut program 64 defines what constitutes the undercut limit for a specific machine on a specific paving area, which is the value initially set by the machine operator. It then determines the position of the swing arm relative to the machine by determining the position of the swing arm relative to the machine, by determining the lateral tilt of the machine, and by determining the displacement and direction of the machine. If the machine leaves the face end and the swing arm position is below the scoring limit, machine travel is stopped.

[0017] Roof jackets 68 (shown schematically in Fig. 3) covering and protecting the wall cutting machine 26 are aligned along the surface of the excavation. The number of shields is known, as are the shields that are present near the face ends of the longwall face is also known. Covers between the face and the face ends are also known and define the point where the face ends and the face ends start and vice versa.

[0018] More specifically, the mining machine 26 comprises a plurality of sensor means mounted on the machine and adapted to measure various parameters of the mining operation, and to generate electrical signals representing said parameters. The first sensor means it provides

- an inclinometer 56 mounted at the pivoting point of each of the pivot arms 42 is adapted to measure the positions of each of the arms relative to the machine 26, while the second sensor means, which is a sensor 55 mounted on the drive gears of the cutter, is adapted to measure the movement and direction of the machine 26. A third of said sensor means, which is the tilt and lateral tilt sensor 54, is adapted to take measurements along the lateral tilt of the face (see Fig. 2) of the machine 26. If necessary, the tilt of the machine may also be taken into account (not shown) in determining the position of the swivel arm in relation to the excavation ground.

[0019] Even more specifically, the method comprises the steps of locating the first and second sensor means, indicating the machine direction of travel and machine position relative to the mineral surface by signals, electrical signals indicating the machine travel direction, and the machine position relative to the mineral surface, and electric signals indicating the position of the pivot arm relative to the machine and processing by the machine controller the electric signals to determine whether the machine is leaving the face and, if the position of the pivot arm is below the scoring limit, stopping the machine from moving.

[0020] Figures 4 to 9 further illustrate details of the undercutting protection program according to this disclosure. More specifically, setting the initial parameter to one initially starts the anti-undercutting program 64. When this parameter is set, the program runs and determines whether the cutter is on the face run. This is done by comparing the current roof sheath number to the sheath numbers present at the ends of the face face (CurrentSupport> = HeadgateUndercutShield) as shown in Fig. 3. If the cutter 26 is on a plane, then the program restricts the swing arm or the boom to traverse below the scoring limit by executing the left boom swing limit process 73 and the right boom swing limit process 74. If the cutter is not on the face run, then the program executes face end process 70.

[0021] When program 64 is executing the face end process 70, the program first checks in which direction the cutter is proceeding. If the cutter 26 leaves the end of the face, as determined by checking the number of the particular support roof cover, then the drag process 76 for the swing angle and the drag process 78 are initiated by the tractor. The drag process 76 for the swing angle is performed first and checks the position of the swing arm (LeftBoomAngle) for the initial offset value (LeftBoomOffset), corrected for the machine sideline (MachineRollAngle + RollOffSet). This value is then compared to the undercutting limit (MaxUndercutAngle), and if the value falls below this limit, the hauling or movement of the cutting machine is stopped. The program then executes the process of blocking the haul by the tractor, in which the boom swing angle is checked again until the boom swing angle no longer falls below the undercutting limit. If the boom swing angle no longer falls out

- 6 below the scoring limit, the drag lock is removed and the machine can continue to run to the end face.

[0022] If the software stops the machine, a message from the Cutter Status screen explains that the undercut limit has been exceeded. It is also possible for a light to flash somewhere on the machine, but not all machine has lighting. The machine will operate normally, but will not resume drag until the swing arm is raised above the parameter limit. The alarm message is "drag disabled, swing arm below scoring limit". The auxiliary text is from the control system which has detected that the swing arm has reached the undercut limit while it is in the course of the end face. The maximum scoring angle is defined by the parameter.

[0023] Possible reasons for the controller to indicate an undercutting situation are that the operator has lowered the swing arm too much, or the tilt-arm inclinometer is not calibrated or the lateral / longitudinal tilt sensor is not calibrated. The invention is defined as in the claims that follow.

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