JP2010521603A - Rock drill control method and apparatus and rock drill - Google Patents

Abstract

The method and apparatus according to the present invention is a power supply control method and apparatus for a rock drill (2) movable back and forth on a feed beam (3) provided with an impact device and a rotary motor for providing a rotational moment. , Parameters relating to the rotational moment are monitored, the power supply is controlled by flow control according to variations in the value of the parameter, and the supply flow rate to the fluid motor means providing the power supply is increased by a rotational moment higher than the first level. Is reduced in proportion to the change in the parameter value corresponding to. For parameter values corresponding to rotational moments lower than the first level, the power supply is controlled by pressure control according to fluctuations in parameter values, and the supply pressure to the fluid motor means corresponds to an increase in rotational moment. It is reduced in proportion to the change of the parameter value. The present invention also relates to a rock drill and a rock rig.
[Selection] Figure 1

Description

  The present invention relates to a method and a device for controlling the power supply of a rock drill as described in the preamble of each independent claim.

  During impact rock drilling, a shock wave is generated that is transmitted through the shank adapter and drill string to the drill bit. When the shock wave reaches the drill bit, the hard metal stud is pushed into the rock and a strong force is generated that destroys the rock. For hard metal pins that will come into contact with undestructed rock after striking, the drill steel is rotated using a rotating device with a rotary motor and transducer (often hydraulically driven).

  The rock drill itself is provided on a slide which can be moved back and forth on the feed beam. The rock drill and slide are driven against the rock along the feed beam by a power supply motor in the form of a hydraulic cylinder or chain feeder, for example.

  When it comes to rock drilling, there is always a risk that the drill will hit the stack. This results in a difficulty in releasing the drill string and causes production to be reduced due to lost production time and lost drill string. The need to pull out the drill string in the drill hole is a difficult problem to solve, in addition to the cost of the string and drill bit, in connection with the loading of the broken rock, There is also a risk that lost or equipped drill bits can damage the grinder.

  According to the prior art, when the rock drill tends to hit the stack, a higher moment is required to rotate the drill bit, thus increasing the rotational pressure on the rotary motor.

  When the excavation operation is started, the rotational pressure is increased and, in the normal case, the pressure level is between “idle rotational pressure” and “rotational pressure target value”. If the rock drill tends to hit the stack during excavation, the rotational pressure will be increased. When the rotational pressure exceeds the “required rotational pressure” level, the supply pressure is reduced in proportion to the rotational pressure to a certain level, ie, “minimum supply pressure for excavation”. This pressure level is generally just as large as the level to overcome friction and move the rock drill. This is done to reduce the pressure between the rock and the drill bit and to reduce the risk of the rock drill hitting the stack.

In spite of this, if the rotational pressure continues to rise to a level corresponding to “Drill Stack Limit”, the protection function against stack excavation is activated and the rotational pressure is lower than the level corresponding to “Limit after Drill Stack”. Until then, the drill slide is fed backwards and the impactor pressure is reduced to "pressure at start of excavation". The drill slide is inverted by the set value of “time for reverse feed during drill stacking” (tf). If the drill stack does not end within the set time (tf), all rock drilling functions are stopped.
International patent publication WO1997 / 49895 can be described as a representative example of the prior art.

International Patent Publication No. WO1997 / 49895 International Patent Publication WO2006 / 108918

  The problem with the prior art is that excavation can be a convulsive experience. When the rotational pressure rises above the “drill stack limit” and the protection function for the drill stack is activated, the jackhammer is suddenly drawn backwards, often causing an unpleasant experience and even against the jackhammer. Can be harmful.

  International Patent Publication No. WO 2006/108918 relates to a method for controlling a rock drilling process, and controls the feed of a rock drill using the pressure difference of a rotary motor. When the rotational resistance increases until the pressure difference exceeds the threshold value, the feed is switched to reverse motion. In this method, when the pressure lower than the threshold value increases, a feed control valve controlled by a separate feed adjustment valve is provided to reduce the feed motor flow rate. The problem with this configuration is that the control by the system is inaccurate, specifically, the control at the start of the control process is inaccurate.

  It is an object of the present invention to provide a method and apparatus that eliminates or at least reduces the problems of the prior art.

  This object is obtained with the method and device described above through the features of the independent claims.

  The basic concept according to the present invention is to provide a combination of pressure control and flow control for power supply to the feed motor, when the rock driller tries to excavate the stack, in other words, the rotational pressure is at the first level. The goal is to obtain smoother and more flexible control when increasing higher. The first level may be an experimentally determined value for a parameter when the rotational moment (torque) and thereby the rotational resistance increases above a value that can be considered to correspond to a normal rock drilling operation. . By controlling the pressure at the start of the control process, a great advantage is achieved that the direct action of the system with reduced play and reduced delay is achieved. The combination of these different principles yields characteristics that are not anticipated by those skilled in the art that can take advantage of each control principle and avoid its disadvantages.

  More particularly, the advantage of this control principle is that adjustment of the drill bit strength against the rock can be achieved through pressure control using parameter values below the first level. By switching to flow control when the first level is exceeded, it is possible to control the speed of the rock drilling machine with the same maximum yield strength during the entire process.

  Preferably, the supply pressure and the supply flow rate are each reduced or increased in proportion to the change of the parameter value corresponding to the rotational moment of each region, which can be realized using reliable simple components. .

  Also preferably, the supply flow rate is reduced to bear a negative value corresponding to the reverse feed for a parameter value corresponding to a rotational moment higher than the second level. Therefore, to change the direction, the rock drill will move backward at an increased speed when the rotational resistance further increases. This reduces the demand for the drill stack function.

  According to an embodiment of the present invention, the drill stack function includes preset rock drill parameters that are activated at parameter values corresponding to rotational moments higher than the third level. Compared to the known prior art, according to the present invention, this drill stack function is activated in the rare situation during excavation, and there is an advantage that productivity is improved and operation efficiency is improved. It is done. Furthermore, even if the drill stack function has to be activated after all, this change becomes quite smooth since the rock drill has already started moving backwards when this function is activated. This reduces the burden experienced by the operator and also reduces the load on the rock drill and drill steel. Another advantage is that the drilling machine has already begun to move backwards before the drill stack function is activated, and this direction reduces the condition of the severe drill stack, which can result in a “drill stack limit” There is.

  Preferably, the parameter relating to the rotational moment is one of a group of rotational pressure, moment detected by the rotor transducer, and rotational speed. Specifically, since the rotational pressure is easy to measure and monitor and can be predicted in direct relation to rotational resistance, the parameter is preferably rotational pressure.

  In general, it is not desirable to limit the forward feed of a rock drill during excavation. For that reason, the corresponding valves are adjusted so that they do not have any flow restriction on the supply flow rate. The effective supply flow rate will be determined by the supply motor, which is usually well below the flow rate that can pass through the valve. Therefore, if the change is executed so that the pressure control is terminated at the same time as the flow control is started during the change from the pressure control to the flow control, the flow control valve has a dead zone, that is, has play and control. There is a risk that will become inaccurate.

  By overlapping the power supply flow control and pressure control with each other in the range of the parameter value in the first level region, this problem is avoided, further reducing play and deadband in the system Elimination is achieved. In practice, this overlap will cause the valve to move in the closing direction so that when changes between control principles occur, the valve settings will be adapted to the actual flow rate and will not affect the system during the overlap. It can be achieved by controlling. The length of the overlap may be determined through experimentally determined values or based on measurements of actual flow rate, excavation speed or any other suitable parameter. The adjustment of the valve may be manual or automatic.

  Preferably, during normal excavation between the idle rotational pressure and the rotational pressure target value, power supply control is not performed, and the supply pressure and the supply flow rate are kept constant. As a result, the system appropriately shifts to pressure control when the rotational pressure target value is exceeded.

  Corresponding advantages are obtained by the claims relating to the corresponding device.

1 diagrammatically shows a drilling rig equipped with a device according to the invention with a control system. It is a graph which shows the supply pressure proportional to a rotation pressure. It is a graph which shows the supply flow rate proportional to a rotation pressure. It is a figure which shows the flow of a method with the form of a flowchart. It is a figure which shows the hydraulic circuit for demonstrating the difference between flow control and pressure control.

  The invention is explained in more detail below by means of several embodiments with reference to the accompanying drawings.

  In FIG. 1, the code | symbol 1 has shown the rock drilling rig for rock drilling, and this rock drilling rig 1 is supporting the feed beam 3 on a drill arm. The rock drill 2 can move back and forth on the feed beam 3 and acts on a drill string 4 having a drill bit 5 attached to the tip, as in the prior art.

  The rock drill 2 is provided with a rotating device (not shown) for rotating the drill string 4 during excavation by a known method. The rotary motor is hydraulically driven by the rotary flow coming out of the pump 7 via the conduit 8. The pressure in the conduit 8 is a rotational pressure and is sensed by the pressure sensor 9.

  The rock drill 2 is driven by a feed force F during its reciprocating motion using a supply motor (not shown) that is hydraulically driven at a supply flow rate supplied by a pump 10 via a supply conduit 11. The pressure in the supply conduit 11 is the supply pressure and is sensed by the pressure sensor 12. Reference numeral 6 denotes a central processing unit (CPU) that receives signals from pressure sensors 9 and 12 and monitors the pressure in these conduits. The CPU 6 communicates with the pumps 7 and 10 in addition to the rock drill 2 when it is in the controlled state. Furthermore, the CPU 6 preferably also has other functions, which are not the subject of the present invention and will not be described here.

Figure 2 is a graph showing the supply pressure P _M as a function of the rotation pressure P _R. Figure 3 is a graph showing the supply flow rate as a function of the rotation pressure P _R. During normal excavation, the rotational pressure is between the “idle rotational pressure” _Pi and the “rotational pressure target value” _PRB . This gives "supply pressure drilling" and "flow drilling".

  When the rotational pressure increases beyond a limit value appropriately set so as to become the “rotational pressure target value”, the supply pressure is reduced in proportion to the continuous increase of the rotational pressure. The supply pressure is suitably reduced to the “minimum supply pressure drilling” level. The level of “minimum supply pressure drilling” may preferably be the pressure required to overcome the friction between the feed beam and the slide, but may be higher.

  If the rotational pressure continues to increase higher than the first level P1, the control principle is switched from pressure control to flow control. In doing so, the flow to the rock drill is reduced in proportion to the increase in rotational pressure, and at the same time the supply pressure is kept constant at the level of “minimum supply pressure excavation”.

Rotation pressure P _R is, continued to increase to a second level P2 corresponding to the reduction rate of the rock drill is adjusted until the zero, resulting switching of the pressure, so that the rotation pressure P _R is increased more Then, the jackhammer begins to be sent backwards. The supply pressure level is then defined as “rear feed pressure”. If an arm with a chain feeder is used, this pressure level will be roughly “minimum supply pressure drilling”, but if a cylinder feeder is used, the rear drive area will drive forward. This pressure level is considerably higher because it is not as large as the area.

When the rotation pressure P _R continues to increase, the flow rate is increased as opposed to the previous direction, the rock drilling machine, will move at a higher rearward speed.

If the rotational pressure continues to increase further, the rotational pressure reaches the third rotational pressure level P3 “Drill Stack Limit”. This means that the drill stack protection function is activated, thereby setting certain predetermined rock drill parameters. The drill slide is then fed backwards until the rotational pressure is below the “post-drill stacking limit”. The “limit after drill stack” is a value set with a lower rotational pressure than the “drill stack limit”. During the retracting motion, the impactor pressure is reduced to color the pressure. Drill stack protection function, to activate the "reversal time for the feed at the time of the drill stack" t _f. If the drill stack is not yet stopped, all drill functions are terminated.

  In addition to the drill stack protection function, the method according to the invention can be fully softwareized and all parameters can be set and modified by the operator or maintenance personnel.

  FIG. 4 shows the sequence of the method in the form of a flowchart.

Position 19 indicates the start of the sequence.
Position 20 indicates normal excavation using a rotational pressure between “idle rotational pressure” and “rotational pressure target value”. In this normal excavation, “supply pressure excavation” and “supply flow excavation” are performed, in which the function is completely inactive and no adjustment is made. During the rotation pressure monitors, rotation pressure P _R is the pressure P _RB, i.e., whether or not increased higher than the rotation pressure target value is observed. When the rotation pressure P _R is not higher than the rotation pressure target value P _RB, the system returns to position 20. However, when the rotation pressure _{P R} is higher than the rotation pressure target value _{P RB,} the system switches to position 21.

At the position 21, the rotational pressure is increased higher than the limit value “rotational pressure target value”. The system switches to the supply pressure control, it continues to monitor the rotation pressure P _R. Rotation pressure P _R is greater than the pressure P1 corresponding to the increase in the rotational motion exceeds the first level, according to the present invention, the system is switched to position 22.

Position 22 means a shift to rock drill feed flow control, where the flow to the rock drill feed is reduced in proportion to the increase in rotational pressure, and at the same time the supply pressure is , Held at a “minimum supply pressure drilling” level. When continuously monitors the high rotational pressure than the first level, the rotation pressure P _R is the pressure P2, i.e., whether it exceeds the second level is determined. When the rotation pressure P _R is not greater than the second level P2, the system directly cut into the process after the position 21換Ru. However, if the rotation pressure P _R is greater than the second level P2, the system is switched to position 23.

  At position 23, a shift is made with the supply pressure to the rock drill feed, with the result that the rock drill is moved backwards. The flow rate to the jackhammer feed remains changed in proportion to the change in rotational pressure.

When the rotation pressure is continuously monitored, whether the rotation pressure P _R is greater than the pressure P3 is determined. The pressure P3 is the third level of rotational pressure which means the limit for the drill stack. If the rotation pressure P _R is not greater than the third level P3, the system is directly returned to the process after the position 22. However, when the rotation pressure P _R is greater than the third level P3, the system is switched to position 24.

Position 24 means the activation of the drill stack protection function.
When the drill stack protection function is activated, specific preset rock drill data is activated over a predetermined time “time for reverse feed during drill stack” tf. When tf has elapsed, whether left rotation pressure P _R exceeds a third level P3 is determined. When the rotation pressure P _R is not greater than the third level P3, the system directly, is switched to the process after the position 23. However, the rotation pressure P _R is, when the remains above the third level P3, the system is switched to position 25.

  At position 25, when the drill string with the drill bit considers it to drill the stack to a length that cannot be released through this function of the rock drill, the rock drill stop process is initiated. The excavation is then switched to manual control by the operator.

  Position 26 indicates the end of the sequence.

  The present invention can be modified within the scope of the claims and is not limited to the above-described embodiments. Therefore, even if the proportional flow control described above is preferable, the adjustment can be performed by a method other than the proportional flow control. All limit values and levels can be adjusted according to the situation being implemented and existing equipment, for example, flow control may be initiated when the rotational pressure exceeds a “rotational pressure target value”.

  The processing of position 21 can be finished so that the supply pressure is reduced when the value of the parameter is increased within the time interval for the value of the parameter below the first level. The supply pressure can be reduced in proportion to the increase in the value of the parameter, or it can be reduced at the moment when the value of the parameter is increased. FIG. 2 shows an example in which the supply pressure is decreased proportionally when the “rotation pressure target value” is exceeded. Instead, the supply pressure is almost instantaneously until “minimum supply pressure excavation”. It can also be reduced. The supply pressure for “minimum supply pressure drilling” is the same as the supply pressure that is effective during the main part of the flow control, as described with respect to FIG. In this case, the graph of FIG. 2 is instantaneously lowered to “minimum supply pressure excavation”, that is, a trajectory different from that shown in FIG. 2 is passed.

  Also, in addition to the rotational pressure, the parameter to be monitored and measured can be sensed instantaneously in the rotor transmission, for example with a known torque sensor, and the rotational speed can be sensed with a rotational speed sensor. .

  The means for providing the inventive action in the device according to the invention are the known conventional adjustment devices and control devices.

  The means for monitoring the parameters relating to the rotational moment and controlling the supply force in response to changes in the values of the parameters is suitably a CPU combined with a sensor on the one hand and a CPU combined with a flow control device on the other hand. It is.

  The means for reducing or increasing the supply force by changing the supply flow rate to the fluid motor means for supplying in relation to the change of the parameter value is suitably a CPU combined with a fluid regulator. .

  The means for activating the drill stack function with preset rock drill parameters is suitably implemented through a CPU combined with mechanical setting means.

  In another embodiment of the above-described drill stack function, the rock drill is simply and quickly fed backwards without another auxiliary function. The present invention assumes no drill stack function in its superordinate concept.

  Advantageously, the supply flow control and the supply pressure control overlap each other within the interval of the value of the parameter within the first level. Specifically, depending on the experimental flow rate value, measured supply flow rate, or measured or estimated excavation speed group, the valve that adjusts the supply flow rate is in the closing direction before the pressure control is finished. It can begin to be adjusted. Through the overlap, the play and dead zone that can be in the system can be further reduced and even eliminated completely. In practice, the overlap can be achieved by a valve to be adjusted in the valve closing direction, so that when switching occurs between the control principles, the valve setting becomes more adapted to the actual flow rate.

  The adjustment of the valve can be performed manually or automatically. Referring to FIG. 3, the irregular graph shows the actual flow rate during actual excavation. Reference numeral 39 indicates the progress of the flow rate during the flow rate control. By applying the overlap principle described above, the flow rate control is started before the pressure control is finished, and the graph is shown at 40. The dead zone where the control shown by section 41 becomes unstable can be avoided through this variant of the invention, where the control becomes clear and over the entire control region, in particular the switch between control principles. It becomes more accurate at the time. Explaining the principle of overlap with respect to the “first level”, the pressure control is continued beyond this time when the flow control is started, and conversely, the flow control is the “first level”. Begun some time ago.

Reference is now made to FIG. 5 to illustrate the difference between flow control and pressure control. For flow control, a pressure compensation valve can be used, and the pressure difference between the inside and outside of the main valve 27 of the supply motor 29 is adjusted by the valve 28. The purpose of this adjustment is to keep the pressure difference as constant as possible.
Since the flow rate is expressed by the following equation, the flow rate only depends on the setting of the valve that gives the opening area.
(Formula) Flow rate = Opening area x √ Pressure difference

  For pressure control, a pressure limiter 30, for example, an electronically controlled pressure limiter is used. When the pressure exceeds a predetermined level, the valve opens into the tank and the pressure in the conduit is reduced so that valve 28 is closed.

  Another solution for controlling the flow rate is to adjust the flow rate from a pump 31 having either a rotational speed control hydraulic pump or a hydraulic pump capable of controlling the amount of displacement. Although FIG. 5 is independent from FIG. 1, the pump 31 in FIG. 5 corresponds to the pump 10 in FIG.

Claims (23)

A power supply control method for a rock drill (2) movable back and forth on a feed beam (3) provided with an impact device and a rotary motor for providing a rotational moment,
Parameters related to rotational moments are monitored,
The power supply is controlled by flow control according to the variation of the parameter value,
In the power supply control method, the supply flow rate to the fluid motor means for providing power supply is reduced in proportion to the change of the parameter value corresponding to the increase of the rotational moment higher than the first level.
For parameter values corresponding to rotational moments lower than the first level, the power supply is controlled by pressure control in response to variations in the parameter values,
The power supply control method, wherein the supply pressure to the fluid motor means is reduced in proportion to a change in parameter value corresponding to an increase in rotational moment. The method of claim 1, wherein the supply pressure is reduced or increased in proportion to a change in parameter value corresponding to a rotational moment below the first level. The method according to claim 1 or 2, characterized in that the supply flow rate is reduced or increased in proportion to a change in parameter value corresponding to a rotational moment higher than the first level. The supply flow rate is reduced to bear a negative value corresponding to the rearward power supply for a parameter corresponding to a rotational moment higher than the second level. The method described. The method according to claim 1, wherein the drill stack protection function with preset rock drill parameters is activated when the parameter value corresponds to a rotational moment higher than the third level. 6. The parameter according to any one of claims 1 to 5, wherein the parameter relating to the rotational moment is one of a group of rotational pressure, a sensed moment in a rotor transducer, and a rotational speed. the method of. The method according to claim 1, wherein the flow control and the pressure control of the power supply overlap each other within the interval of the value of the parameter in the first level region. . The supply flow adjustment valve begins to adjust in the valve closing direction before pressure control is stopped, depending on any one of the group of experimental flow values, measured supply flow, measured or estimated drilling speed The method according to claim 7. The method of claim 1, wherein the supply pressure is instantaneously reduced while the parameter value is increasing. The power supply control is not performed on the rotational pressure value corresponding to the normal excavation between the idle rotational pressure and the rotational pressure target value, and the supply pressure and the supply flow rate are kept constant. Item 10. The method according to any one of Items 1 to 9. The method according to claim 10, wherein the system switches to pressure control when the rotational pressure target value is exceeded. A power supply control device for a rock drill (2) movable back and forth on a feed beam (3) provided with an impact device and a rotary motor providing a rotational moment,
Monitoring means for monitoring parameters relating to rotational moments;
By reducing the supply flow rate to the fluid motor device that provides the power supply in proportion to the change in the parameter value corresponding to the increase of the rotational moment higher than the first level, the power supply is adjusted according to the variation of the parameter value. A power supply control device comprising a flow rate control means for controlling,
For a parameter value corresponding to a rotational moment lower than the first level, the pressure control means for controlling the power supply according to the variation of the parameter value,
A power supply control device, characterized in that the supply pressure to the fluid motor means is reduced in proportion to a change in parameter value corresponding to an increase in rotational moment. The apparatus of claim 12, wherein the pressure control means is configured to reduce or increase the supply pressure in proportion to a change in parameter value corresponding to a rotational moment below a first level. The fluid control means is configured to reduce or increase a supply flow rate in proportion to a change in a parameter value corresponding to a rotational moment higher than a first level. apparatus. The flow rate control means is configured to reduce the supply flow rate so as to bear a negative value corresponding to the rearward power supply for a parameter corresponding to a rotational moment higher than the second level. Item 15. The apparatus according to any one of Items 12 to 14. 16. A drill stack protection function having a preset rock drill parameter configured to be activated at a parameter value corresponding to a rotational moment higher than the third level. A device according to claim 1. 17. The parameter according to claim 12, wherein the parameter related to the rotational moment is one of a group of a rotational pressure, a sensed moment in the rotor converter, and a rotational speed. Equipment. The flow rate control means and the pressure control means are configured to overlap the flow rate control and the pressure control within an interval of the parameter value in the first level region. The apparatus as described in any one of 12-17. Depending on one of the group of experimental flow value, measured supply flow rate, measured or estimated excavation speed, the supply flow adjustment valve will supply the supply flow rate in the valve closing direction before pressure control is stopped. The apparatus according to claim 18, further comprising means for initiating control of the valve to adjust the pressure. The rotary pressure value corresponding to the normal excavation between the idle rotational pressure and the rotational pressure target value is not adjusted, and means for holding the supply pressure and the supply flow rate is provided. Item 20. The method according to any one of Items 12 to 19. 21. The method of claim 20, comprising means for switching the system to pressure control when the rotational pressure target value is exceeded.   A rock drill comprising the device according to any one of claims 12 to 21.   A rock drilling rig comprising the rock drilling machine according to claim 22.

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