Control device for drilling machine and drilling machine

Abstract

To provide a control device of a boring machine for achieving automatic control capable of avoiding redundant control at low cost.SOLUTION: A pressure sensor 25 that measures a flushing pressure which is a pressure of compressed air discharged by the flushing mechanism 18, and a control unit 21 that sets operations of the striking mechanism 9, the rotation mechanism 10, the feed mechanism 11, and the flushing mechanism 18, wherein three or less types of operation patterns are set for each of the mechanisms, further, at least four types of control levels, which are a normal control level for normal drilling and a first control level, a second control level, and a third control level that are applied when an appropriate drilling condition is different from that at the time of normal drilling, are set as a set of control levels in which one operation pattern is assigned to each mechanism, and the control unit sets the operation of each mechanism by selecting the control level based on only the flushing pressure.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device for a drilling machine and a drilling machine equipped with the control device for the drilling machine. [Background technology]

[0002] Rock drills equipped with a striking mechanism and a rotation mechanism have been used to drill blast holes in rock. Generally, such rock drills are mounted on a guide shell equipped with a feed mechanism. The guide shell is mounted on a traveling vehicle equipped with an operator's cabin via a boom that can change its position within a predetermined range at the front of the vehicle. A flushing mechanism is also connected to the guide shell to discharge cuttings from the blast hole during drilling, forming a well-known drilling machine.

[0003] This type of drilling machine drills a hole to the desired depth by transmitting the impact and rotational forces generated by the rock drill to a rod equipped with a bit at its tip while the rock drill is advanced along the drilling direction on the guide shell. If the length of the leading rod equipped with a bit is shorter than the desired drilling depth, the rock drill is reversed from its forward position to a predetermined position, a rod without a bit is connected to the rear end of the leading rod, and the rock drill is advanced again to extend the rod length and continue drilling. After repeating this process to drill the blast hole to the desired depth, the reverse operation of the rod extension is performed to pull out the leading rod while disconnecting it, completing the drilling process.

[0004] The flushing mechanism is a mechanism for discharging the cuttings generated when the bit crushes the rock during such drilling operations from inside the blast hole. A known flushing mechanism is one in which compressed air is supplied from a compressor mounted on the vehicle to the tip of the bit through the inside of the rod, generating a powerful airflow from the tip of the blast hole toward the ground surface, thereby discharging the cuttings. In addition to the flushing mechanism, drilling machines are also known that are equipped with a collection device that collects the cuttings discharged to the surface and moves them to a location away from the blast hole opening, such as the rear of the traveling vehicle.

[0005] When drilling using such drilling machines, parameters such as the hardness and water content of the rock to be drilled vary greatly depending on the geology of the area being drilled in. Furthermore, even in geologically homogeneous areas, the actual parameters vary depending on the drilling location and even the drilling depth. Therefore, the operator of the drilling machine must monitor the operating status of the impact mechanism, rotation mechanism, rock drill feed mechanism, and flushing mechanism, and also use the vibration and drilling noise of the rock drill as criteria to set the optimal operating conditions.

[0006] When setting the operating conditions, if the amount of crushing energy input is not commensurate with the rock mass, work efficiency will decrease, and if excessive crushing energy is input, equipment wear will be accelerated. Also, if cuttings are not discharged properly, the bit or rod may become stuck and jam, not only stopping the drilling operation but also making it difficult to retrieve the rod.

[0007] As such, the task of drilling blast holes relies heavily on the skill of the operator, and given the situation in which it is becoming increasingly difficult to secure skilled operators, many technologies have been proposed to reduce the labor required for drilling machines and automate them (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-61368 Summary of the Invention [Problem to be solved by the invention]

[0009] The technology of Patent Document 1 is to provide a sensor for each mechanism that constitutes the drilling machine, and to control the constituent equipment based on the detection values ​​of each sensor, thereby fully automatically controlling the drilling work. Therefore, the technology of Patent Document 1 has the problem of high costs because it requires the installation of many sensors and the use of dedicated equipment to be controlled.

[0010] Furthermore, even if the component equipment is controlled based on the detection values ​​of each sensor, the conditions inside the rock are extremely complex and change every moment, making it difficult to accurately grasp them.In addition, there are countless patterns for the relationships between control parameters, making it difficult to select appropriate operating conditions.As a result, the reality is that complete automation of drilling operations has not yet become widespread.

[0011] On the other hand, fully automated drilling machines such as those in Patent Document 1 tend to be avoided as redundant control because, as mentioned above, it is necessary to set operating conditions on the safe side to compensate for the difficulties inherent in fully automatic control, and this may slow down the progress of work for relatively skilled operators.

[0012] Therefore, the present invention has been made with an eye on the above-mentioned problems with drilling machines, and its object is to provide a control device for a drilling machine that is low-cost and realizes automatic control that can avoid redundant control. [Means for solving the problem]

[0013] In order to solve the above problems, the control device for a drilling machine of the present invention is provided with a drilling machine having an impact mechanism, a rotation mechanism, a feed mechanism, and a flushing mechanism, and is equipped with a pressure sensor that measures the flushing pressure, which is the pressure of the compressed air discharged by the flushing mechanism, and a drilling condition setting means that sets the operation of each mechanism, and each of the mechanisms is set with three or less operating patterns, and further, at least four control levels are set, each of which is assigned one of the operating patterns, including a normal control level for normal drilling, and a first control level, a second control level, and a third control level that are applied when the appropriate drilling conditions are different from those for normal drilling, and the drilling condition setting means sets the operation of each of the mechanisms by selecting the control level based only on the flushing pressure. [Effects of the Invention]

[0014] According to the present invention, the drilling conditions are determined using only the flushing pressure as a parameter for determining the state inside the rock mass, thereby providing a control device for a drilling machine that realizes automatic control at low cost and avoids redundant control. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an explanatory view of the entire drilling machine showing a control device for a drilling machine of the present invention; [Figure 2] 1 is a diagram showing a guide shell, which is a main component of a drilling machine illustrating a control device for a drilling machine according to the present invention. [Figure 3] 1 is a diagram showing the configuration of a control device for a drilling machine according to the present invention; [Figure 4] FIG. 2 is a diagram showing a control matrix of the control device of the drilling machine of the present invention. [Figure 5] FIG. 2 is a diagram showing a control flow of the control device of the drilling machine of the present invention. [Figure 6] FIG. 2 is a diagram showing a control flow of the control device of the drilling machine of the present invention. [Figure 7] FIG. 2 is a diagram showing a control flow of the control device of the drilling machine of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings are schematic. Therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. differ from the actual ones, and the drawings also include portions where the relationship and ratio of dimensions differ from each other. Furthermore, the embodiments described below are intended to exemplify devices and methods for embodying the technical ideas of the present invention, and the technical ideas of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0017] <Structure of drilling machine> The structure of the drilling machine will be described with reference to FIG. The drilling machine 1 comprises a traveling carriage 2 and a guide shell 7 . The traveling carriage 2 comprises a carriage body 3, a track frame 4 and an operator cabin 5. The carriage body 3 is equipped with an engine (not shown) that is the power source of the drilling machine 1, a flushing mechanism 18, a dust collector 19, a hydraulic pump Pp (FIG. 3), and various other hydraulic and pneumatic devices that are hydraulic and pneumatic devices, and a control device 20 that controls these hydraulic and pneumatic devices. Details of these hydraulic and pneumatic devices will be described later. A boom 6 is provided at the front of the traveling carriage 2. The rear end of the boom 6 is supported by the traveling carriage 2 and the tip of the boom 6 is connected to a guide shell 7. The boom 6 supports the guide shell 7 so that its position can be changed within a predetermined range.

[0018] <Structure of guide shell and flushing mechanism> The structures of the guide shell 7 and the flushing mechanism 18 will be described with reference to FIGS. In FIG. 3, solid arrows indicate hydraulic connections and mechanical energy transmission relationships between the components, dashed arrows indicate electrical signal connections, and dashed dotted lines indicate compressed air connections.

[0019] As shown in FIG. 1, a rock drill 8 is provided in the guide shell 7 so as to be able to move back and forth by a feed mechanism 11 that generates a propulsive force in the excavation direction. A rod 12 is attached to the rock drill 8, and a drilling bit 13 is attached to the tip of the rod 12. The bit 13 is a part fixed to the tip of the rod 12 to break up the rock mass, and is only provided on the lead rod. In other words, it is not provided on the other rods 12 that are added on to extend the drilling depth. Therefore, when it is necessary to distinguish between them hereinafter, the rod 12 with the bit 13 fixed to its tip will be called the lead rod 12a, and the other rods will be called extension rods 12b.

[0020] A rod changer 14 and a rod magazine 15 are provided on the side of the guide shell 7. A plurality of extension rods 12b are loaded in the rod magazine 15. When an extension rod 12b is to be added, the rod changer 14 takes out the extension rod 12b from the rod magazine 15 and moves it to a position where it is connected to the rock drill 8.

[0021] As shown in Figure 2, the rock drill 8 is equipped with an impact mechanism 9 that generates impact force and a rotation mechanism 10 that generates rotational force. An open / close centralizer 16 is provided at the tip of the guide shell 7, and a suction cap 17 is provided that can move back and forth along the drilling direction. In Figure 2, only the axes of the leading rod 12a and bit 13 are shown by dashed lines to clearly show the structure of the guide shell 7. The centralizer 16 supports the rod 12 at the tip end side of the guide shell 7 and maintains the state in which the axial direction of the rod 12 is aligned with the feed direction of the rock drill 8 . The suction cap 17 covers the opening of the blast hole BH during drilling work to prevent the discharged cuttings from scattering around. It is also connected to a pipe to the dust collector 19 shown in Figure 1. The dust collector 19 sucks and collects the cuttings from the suction cap 17 via piping and discharges them from the rear of the machine body.

[0022] The flushing mechanism 18 is composed of a series of devices shown in Figure 3 that send compressed air supplied from a compressor (not shown) to the bit 13, spraying it into the blast hole BH being drilled, and generating an airflow to expel the cuttings outside the blast hole BH.

[0023] The compressed air is generated by a compressor (not shown) mounted on the carriage body 3 taking in and compressing the air around the carriage body 3, and is stored in the receiver tank Rt. The compressed air discharged from the receiver tank Rt is sent to the blowhole (not shown) of the bit 13 via the pneumatic modular 18a, air piping 18b, rock drill 8 and air passage 18c formed inside the rod 12, and is sprayed from the bit 13 into the inside of the blast hole BH.

[0024] <Configuration of the control device for the drilling machine> The configuration of the control device 20 will be described with reference to FIG. The control device 20 is composed of a control unit 21, which is a drilling condition setting means provided in the operator cabin 5, known drilling equipment consisting of a pilot modular 22, a main valve 23 and a feed modular 24 provided on the carriage body 3, and a pressure sensor 25, which is a pressure detection unit added according to the present invention. The pressure sensor 25 is configured to be detachable from the drilling machine 1.

[0025] The control unit 21 receives an operation signal from the operator via the console 5a, as well as a flushing pressure, which is the measured pressure of the compressed air detected by the pressure sensor 25. Hereinafter, the flushing pressure input to the control unit 21 will be referred to as the measured value P. The control unit 21 performs operation control processing for the rock drill 8 and the flushing mechanism 18 based on these input signals. Specifically, it outputs a control signal generated by the program 21a to the pneumatic modular 18a and the pilot modular 22. Upon receiving the control signal, the pneumatic modular 18a controls the amount and pressure of compressed air supplied from the receiver tank Rt based on a signal sent from the control unit 21, which will be described later, and the pilot modular 22 operates the spool (not shown) of the main valve 23.

[0026] <Operation pattern setting method using a control device> [Assignment of operation patterns for each control level] With reference to FIG. 4, the allocation of operation patterns of the impact mechanism 9, the rotation mechanism 10, the feed mechanism 11 and the flushing mechanism 18 for each control level will be described. Figure 4 shows the relationship between the measurement value P detected by the pressure sensor 25 and the control level, as well as the operating patterns of the impact mechanism 9, rotation mechanism 10, feed mechanism 11, and flushing mechanism 18 at each control level in a matrix.

[0027] In this embodiment, three types of operation patterns are set for the impact mechanism 9 and the feed mechanism 11, and two types of operation patterns are set for the rotation mechanism 10 and the flushing mechanism 18. In the following explanation, components for which no particular operating pattern is mentioned will maintain the operating mode for normal drilling. Specifically, the impact mechanism 9 is in normal drilling mode, the rotation mechanism 10 is in normal speed rotation mode, the feed mechanism 11 is in normal feed mode, and the flushing mechanism 18 is in the initial setting at the start of drilling work. Furthermore, the "counterbore drilling mode", which is a special operation of the impact mechanism 9, is an operation pattern in which the impact mechanism 9 is operated with a lower impact pressure than during normal drilling, thereby reducing the impact force.

[0028] In this embodiment, a total of four control levels are set, each of which is assigned one operation pattern to each mechanism. Specifically, the normal control level is selected during normal drilling and sets the impact mechanism 9 to the normal drilling mode, the rotation mechanism 10 to the normal speed rotation mode, the feed mechanism 11 to the normal feed mode, and the flushing mechanism 18 to the initial settings at the start of drilling work, and the first control level, Level 1, second control level 2, and third control level 3 are applied when the appropriate drilling conditions differ from those during normal drilling.

[0029] The operation patterns of each control level other than the normal control level are set as follows so as not to overlap with the assignments of other control levels. The first control level Lv.1 sets the impact mechanism 9 to the countersink drilling mode and the flushing mechanism 18 to the strong flushing mode. The second control level Lv.2 operates the impact mechanism 9 in countersink drilling mode for a predetermined time and then sets it to impact stop mode, operates the rotation mechanism 10 in normal speed rotation mode for a predetermined time and then sets it to high speed rotation mode, sets the feed mechanism 11 to feed stop mode, and sets the flushing mechanism 18 to strong flushing mode. The third control level Lv.3 operates the impact mechanism 9 in countersink drilling mode for a predetermined time and then sets it to impact stop mode, operates the rotation mechanism 10 in normal speed rotation mode for a predetermined time and then sets it to high speed rotation mode, sets the feed mechanism 11 to feed backward mode, and sets the flushing mechanism 18 to strong flushing mode.

[0030] Each of these control levels has a set pressure range to which it applies. Specifically, the normal control level is set to a pressure range that includes the initial flushing pressure setting and is lower than any of the other control levels, with the first control level Level 1, the second control level Level 2, and the third control level Level 3 being set to have increasingly higher pressures in this order.

[0031] The threshold value that determines the pressure range for each control level varies depending on the initial state of the flushing mechanism 18 . Although details will be described later, the initial state of the flushing mechanism 18 is the operating mode of the flushing mechanism 18 set during the loop of the repetitive control. Specifically, when the initial state of the flushing mechanism 18 is the weak flushing mode, the set threshold value P1 is used. When the initial state of the flushing mechanism 18 is the strong flushing mode, the reference threshold value P0 and the value obtained by adding the adjustment value a or the adjustment value b to the reference threshold value P0 are used.

[0032] The reference threshold value P0 is corrected as follows according to the number N of rods 12 added by the rod changer 14. P0 = P2 + dP × N P2: Set reference value dP: Increased pressure per rod N: Number of rods [[ID=第十七]]

[0033] [[ID=第十八]] [[ID=第十九]]Here, the relationship between the set threshold value P1 and the reference threshold value P0 is usually P0 > P1. [[ID=第二十]] [[ID=第二十一]]And the selection of the control level is also performed by the value obtained by adding the adjustment values a and b to the reference threshold value P0. Note that the adjustment value a and the adjustment value b are set so that a < b. [[ID=第二十二]] [[ID=第二十三]]Details regarding the setting of the control level will be described next. [[ID=第二十四]] [[ID=第二十五]]

[0034] [[ID=第二十六]] [[ID=第二十七]][Details of the setting of the control level][[ID=第二十八]] [[ID=第二十九]]Referring to FIGS. 5 to 7, the flow when the control device 20 according to the present invention sets the operation pattern will be described. [[ID=第三十]] [[ID=第三十一]]When the drilling operation is started, first, common processing not related to the initial setting of the flushing mechanism 18 shown in FIG. 5 is executed. Note that the drilling machine 1 at the start of the drilling operation is automatically set to the normal control level. [[ID=第三十二]] [[ID=第三十三]]

[0035] [[ID=第三十四]]<00001……>[[ID=第三十五]]In step S01, the loop count C to be used later is reset and the process proceeds to step S02. [[ID=第三十六]] In step S02, it is determined whether weak flushing mode or strong flushing mode is selected as the initial state of the flushing mechanism 18. If weak flushing mode is selected, the process proceeds to step S03 (FIG. 6), and if strong flushing mode is selected, the process proceeds to step S04 (FIG. 7).

[0036] [Initial setting weak flushing mode] First, with reference to FIG. 6, the case where the process proceeds to step S03 will be described. In step S03, the measured value P is compared with the set threshold value P1. If the measured value P is smaller than the set threshold value P1, the process returns to step S02. <P1 S03:NO) That is, this is the process when the inside of the blast hole BH is not clogged and there is no need to change the operation pattern. Therefore, the operation pattern is not changed while the measurement value P is smaller than the set threshold value P1. If the measured value P has increased to a value equal to or greater than the set threshold value P1 (P≧P1 S03: YES), the process proceeds to step S11.

[0037] Here, a step group S10 consisting of a series of processes from step S11 to step S18, which will be explained below, corresponds to the operation content of the first control level Lv.1 of the present invention. The step group S10 shares some of the processing when the initial setting of the flushing mechanism 18 is the weak flushing mode and when it is the strong flushing mode. That is, since the thresholds are a mixture of the set threshold P1 and the reference threshold P0, steps are incorporated to deal with each case.

[0038] In step S11, the first control level is set to Lv. 1. After setting, the process proceeds to step S12. In step S12, it is again determined whether weak flushing mode or strong flushing mode has been selected as the initial state of the flushing mechanism 18. If weak flushing mode has been selected, the process proceeds to step S13, and if strong flushing mode has been selected, the process proceeds to step S50 (FIG. 7) described below.

[0039] In step S13, the reference threshold P0 and the set threshold P1 are compared. When the reference threshold P0 is less than or equal to the set threshold P1 (P1≧P0, S13: NO), the process proceeds to step 40 described later. When the reference threshold P0 is greater than the set threshold P1 (P1<P0, S13: YES), the process proceeds to step S14. When the initial setting is in the weak flashing mode and the relationship between the reference threshold P0 and the set threshold P1 is normal, it is necessary to confirm whether the measured value P is lower than the set threshold P1 suitable for the weak flashing mode. Therefore, the process from step S14 is performed, and it is necessary to reset the mode from the strong flashing mode set at the first control level Lv.1 to the weak flashing mode. However, when the reference threshold P0 is smaller than the set threshold P1 (P0<P1), the processes from step S14 to step S18 can be skipped in order to prevent drilling in the weak mode with an incorrect setting.

[0040] In step S14, it is determined whether n1 seconds, which is the first set time, has elapsed since step S11 was executed. While n1 seconds has not elapsed (S14: NO), the process returns to step S03. That is, the setting of the first control level Lv.1 is maintained for at least n1 seconds. When n1 seconds has elapsed (S14: YES), the process proceeds to step S15.

[0041] In step S15, if the loop count C has not reached the loop upper limit count X (C<X, S15: YES), the process proceeds to step S16. If the loop count C has reached the loop upper limit count X (C = X, S15: NO), the process proceeds to step S40 described later. In step S16, the flashing mechanism 18 is operated in the weak flashing mode and the process proceeds to step S17. In step S17, it is determined whether n2 seconds, which is the second set time, has elapsed since step S16 was executed. While n2 seconds has not elapsed (S17: NO), the process returns to step S16. That is, the operation in the weak flashing mode is maintained for n2 seconds. When n2 seconds has elapsed (S17: YES), the process proceeds to step S18. In step S18, add 1 to the loop count C and proceed to step S40 described below.

[0042] In step S40, compare the measured value P with the set threshold value P1. Even if the operations in the series of step groups S10 are performed, if the measured value P is still greater than or equal to the set threshold value P1 (P≧P1 S40:NO), return to step S02. If the measured value P has decreased below the set threshold value P1 (P<P1 S40:YES), proceed to step S60 shown in FIG. 5.

[0043] Step S60 is a common process that is executed regardless of the initial settings of the flushing mechanism 18, performs a return process to the normal punching mode, and proceeds to step S70. In step S70, determine whether bit 13 has reached the target punching depth. If it has not reached the target punching depth (S70:NO), the punching operation continues while repeating the above-described process. If it has reached the target punching depth (S70:YES), end the punching operation and perform the recovery of the rod described above.

[0044] [In the case of the initial setting strong flushing mode] Referring to FIG. 7, the case where step S04 is entered will be described. First, in step S04, compare the measured value P with the reference threshold value P0. If the measured value P is less than or equal to the reference threshold value P0 (P≦P0 S04:NO), return to step S02. This process is the same as the process in step S03 described above. If the measured value P is greater than the reference threshold value P (P>P0 S04:YES), proceed to step S05.

[0045] In step S05, use the adjusted threshold value P0+a, which is the sum of the reference threshold value P0 and the adjustment value a. Specifically, compare the measured value P with the adjusted threshold value P0+a. If the measured value P is greater than the adjusted threshold value P0+a (P>P0+a S05:YES), proceed to step S6, and if the measured value P is less than or equal to the adjusted threshold value P0+a (P≦P0+a S05:NO), proceed to step S11 (FIG. 5). This process determines whether the problem can be dealt with at the first control level Lv. 1 or whether it is necessary to set the control level to the second control level Lv. 2. If the first control level Lv. 1 is set, the assigned operation pattern is set (S11) and then the process proceeds to step S50 (S12: strong flashing mode).

[0046] In step S06, an adjustment threshold P0+b, which is the sum of the reference threshold P0 and the adjustment value b, is used. Specifically, the measurement value P is compared with the adjustment threshold P0+b. If the measurement value P is greater than the adjustment threshold P0+b (P>P0+b S06: NO), proceed to step S07. If the measurement value P is equal to or less than the adjustment threshold P0+b (P≦P0+a S06: YES), proceed to step S21. This process determines whether the problem can be dealt with at the second control level Lv. 2 or whether it is necessary to set the control level to the third control level Lv. 3.

[0047] [When set to second control level Lv.2] First, the case where the process proceeds to step S21 will be described. Here, the step group S20 consisting of steps S21 to S23, which will be described below, corresponds to the operation content of the second control level Lv.2 of the present invention.

[0048] In step S21, the initial state of the second control level Lv. 2 is set, so that the impact mechanism 9 is set to the countersink drilling mode and the rotation mechanism 10 is set to the normal rotation mode. In step S22, it is determined whether n3 seconds, which is the third set time, have elapsed since step S21 was executed. If n3 seconds have not elapsed (S22: NO), the process returns to step S06. If n3 seconds have elapsed (S22: YES), the process proceeds to step S23. In step S23, the impact mechanism 9 is set to the impact stop mode, and the rotation mechanism 10 is reset to the high-speed rotation mode, and the process proceeds to step S50, which will be described later.

[0049] [When set to the third control level Lv.3] Next, the case where the process proceeds to step S07 will be described. Here, a step group S30 consisting of steps S31 to S33 to be described below corresponds to the operation content of the third control level Lv.3 of the present invention. In step S07, the measured value P is compared with the adjusted threshold value P0 + b. If the measured value P is greater than the adjusted threshold value P0 + b (P > P0 + b, S07: YES), the process proceeds to step 31. If the measured value P is less than or equal to the adjusted threshold value P0 + b (P ≤ P0 + b, S07: NO), the process returns to step S02. The content of the determination in this process is substantially the same as that in step S06. However, depending on the determination result of step S32 to be described below, the repetitive process may be performed while maintaining the third control level Lv.3, and this is provided for the purpose of executing control to check the measured value and determine whether to make a setting change each time in the loop.

[0050] In step S31, the initial state of the third control level Lv.3 is set. Therefore, the striking mechanism 9 is set to the countersink drilling mode, and the rotating mechanism 10 is set to the normal rotation mode. In step S32, it is determined whether n4 seconds, which is the fourth setting time, has elapsed since step S31 was executed. While n4 seconds has not elapsed (S32: NO), the process returns to S'07, and when n4 seconds has elapsed, the process proceeds to step S33. In step S33, the striking mechanism 9 is stopped, the rotating mechanism 10 is operated in the high-speed rotation mode, and the process proceeds to step S50.

[0051] In step S50, the measured value P is compared with the reference threshold value P0. If the measured value P is lower than the reference threshold value P0 (P < P0, S50: YES), the process proceeds to step S60 (FIG. 5) described above. If the measured value P is greater than or equal to the reference threshold value P0 (P ≥ P0, S50: NO), the process returns to step S02.

[0052] <Operating Example of Control Device of Drilling Machine> Next, the operation of the drilling machine 1 in the drilling operation will be described with an example. When drilling the blast hole BH shown in Figure 1, the internal condition of the bedrock R may vary in the depth direction. The internal condition of the bedrock R can be classified into hard rock HR, soft rock SR, fractured zone FZ, and clay layer CL, and the excavation properties and cuttings properties differ. Hard rock HR and soft rock SR are generally called stable rocks, and are known to be layers where the load during excavation and the properties of the cuttings tend to be stable. Fractured zone FZ and clay layer CL are called unstable rocks, and are known to be unstable in the load during excavation and the properties of the cuttings produced, and are prone to problems during excavation.

[0053] As a first example, the operation when the bit 13 enters a layer of unstable rock from a layer of stable rock during drilling will be described with reference to Figures 1 and 5 to 7. In the first example, it is assumed that the initial setting of the flushing pressure is weak.

[0054] While the bit 13 is drilling through a layer of stable rock, the size of the cuttings tends to be stable, and the cuttings can be easily discharged with a constant flushing pressure. Therefore, the measured value P often becomes lower than the set threshold value P1 (S03: NO). However, if the cuttings are not properly discharged from the blast hole BH and become clogged inside the blast hole BH, the compressed air passage inside the blast hole BH becomes narrow, and the flushing pressure increases.

[0055] When the measured value P becomes equal to or greater than the preset threshold value P1 (S03: YES), the normal control level is changed to the first control level Lv. 1 (S10). By changing the operation in this way, the amount of new cuttings generated is reduced, and the strong flushing mode eliminates clogging of the blast hole BH.

[0056] Thereafter, the set threshold value P1 is compared with the reference threshold value P0 (S13). This process determines whether the control level should be switched using the weak flushing mode, which is the initial setting, or whether the strong flushing mode should remain set. If the set threshold P1 is equal to or greater than the reference threshold P0, the measurement value P is compared with the set threshold P1 while maintaining the strong flushing mode (S40). If the set threshold P1 is smaller than the reference threshold P0, the weak flushing mode is reset after n1 seconds have elapsed (S16). Then, after n2 seconds have elapsed since the weak flushing mode was reset, the measured value P is compared with the set threshold value P1 (S40). In either case, if the measured value P falls below the set threshold value P1 (S40: YES), that is, if the properties of the cuttings have stabilized and the blockage in the blast hole has been resolved, the control level is reset to the normal control level (S60).Then, the above process is repeated until the target drilling depth is reached (S70).

[0057] If the measurement value P does not become lower than the set threshold value P1 even when the weak flushing mode is set, the strong flushing mode is set again and the process is repeated (S40: NO, S11). If the measurement value P does not become lower than the set threshold value P1 even after resetting to the weak flushing mode a predetermined number of times and comparing the measurement value P with the set threshold value P1, it is determined that perforation in the weak flushing mode is not suitable, and the strong flushing mode setting is maintained until the measurement value P becomes lower than the set threshold value P1.

[0058] As a second example, a case where the initial setting of the flushing pressure is set to strong when the rock type changes as in the first example will be described. Under these conditions, if the measured value P becomes greater than the adjustment threshold value P0+a (S05, FIG. 5) and is equal to or less than the adjustment threshold value P0+b (S06: YES), the control level is set to second control level Lv. 2 (S20). By setting it in this way, excavation is temporarily stopped to prevent the generation of new cuttings, and the cuttings in the blast hole BH are crushed to make them easier to discharge. Then, the cuttings are discharged using the strong flushing mode.

[0059] This setting is maintained for n3 seconds, and if the measured value P is equal to or less than the adjustment threshold value P0+b during that time (S22: NO, S06: YES), the impact mechanism 9 is set to impact stop mode and the rotation mechanism 10 is set to high-speed rotation mode (S23). By changing the setting in this way, the rod 12 is rotated at high speed, making it easier for the rod to be ejected from the blast hole BH. Furthermore, if the measured value P becomes greater than the adjustment threshold value P0+b during the n3 seconds, that is, if the cuttings are still not properly discharged from the blast hole, the third control level Lv.3 is set (S30).

[0060] If the measurement value P becomes lower than the reference threshold value P0 as a result of this operation, a process of returning to the normal operation level is executed (S60 in FIG. 5). If the measured value P is greater than the reference threshold value P0 (S50: NO), the above operation is repeated to discharge the cuttings.

[0061] If the measurement value P is greater than the reference threshold value P0 and the adjustment value b (S06: NO, S07: YES), the third control level Lv. 3 is set. Since the adjustment value b is set to a larger value than the adjustment value a, the adjustment threshold value P0+b is set to be larger than the adjustment threshold value P0+a. In other words, the adjustment threshold value P0+b is selected when the blockage in the blast hole BH is at its most advanced state. Therefore, by setting the third control level to Lv.3, the cuttings stuck inside the blast hole BH are stirred and crushed, making it easier to discharge from inside the blast hole BH.

[0062] This setting is maintained for a maximum of n4 seconds. If the measured value P falls below the adjusted threshold value P0+b during that time, the process is repeated from the comparison between the measured value P and the reference threshold value P0 (S07: NO, S04). If n4 seconds have passed (S32: YES) after the setting has been changed (S31), the impact mechanism 9 is stopped and the rotation mechanism 10 is reset to the high-speed rotation mode (S33). If the measurement value P decreases below the standard threshold value P0 due to the setting change (S50: YES), that is, if the cuttings are properly discharged and the blockage in the blast hole BH is cleared, the setting is returned to the normal control level and drilling continues (S60, S70). If the measurement value P remains greater than the reference threshold value P0 even after the feed mechanism 11 is moved backward (S50: NO), the process is repeated from the comparison of the measurement value P with the reference threshold value P0 (S04).

[0063] As explained above, the control device 20 according to the present invention selects and sets appropriate drilling conditions based on the flushing pressure. That is, while the flushing pressure is appropriate, it determines that cuttings are being discharged appropriately and selects a normal control level that does not reduce the working speed, and controls the drilling conditions to reduce the working speed only when the flushing pressure increases, so that control is automatically performed to prevent the working speed from being stopped more than necessary.

[0064] <Effects of the present invention> Unlike drilling machines in which sensors are installed in each piece of equipment, such as the configuration disclosed in Patent Document 1, the present invention requires only a pressure sensor 25, making it possible to configure an automatic control system at low cost.

[0065] Furthermore, according to the present invention, only flushing pressure is used as a parameter for determining the state inside the rock mass, and the drilling conditions are determined by limiting the number of operating patterns of each mechanism as a control parameter, thereby implementing very simple drilling control and avoiding redundant control.

[0066] The control concept of the present invention will be considered with regard to avoiding redundant control. Various drilling controls have been proposed for drilling machines to date, and representative examples include so-called RF control, which controls the operation of the feed mechanism using the rotational pressure of the rotation mechanism as a reference parameter, and so-called FP control, which controls the operation of the impact mechanism using the feed pressure of the feed mechanism as a reference parameter.

[0067] The RF control, FP control, and the drilling control of the present invention all share the same objective of preventing jamming and protecting the drill tool. However, there is a significant difference between them in that RF control and FP control place emphasis on improving the straightness of the drilling hole and the rock crushing efficiency by reducing excessive pressure and impact, whereas the present invention places emphasis on improving the discharge of cuttings and maintaining a good finish on the blasthole wall.

[0068] Furthermore, when we look at the relationship between the reference parameters and the water content of the rock in RF control, FP control, and the drilling control of the present invention, we see that the rotational pressure and feed pressure do not respond well to changes in the water content of the rock, whereas the flushing pressure, which is directly affected by the cuttings properties, responds very well to changes in the water content of the rock. Therefore, the controllability of the present invention when the bit passes through a clay layer CL, where the water content fluctuates greatly, is far superior to that of RF control or FP control.

[0069] Furthermore, when focusing on the pressure medium of the reference parameter in RF control, FP control, and the drilling control of the present invention, there is a difference in that the pressure medium in RF control and FP control is hydraulic, while the pressure medium in the present invention is pneumatic. Although it is generally said that pneumatic pressure as a pressure medium of the reference parameter is inferior to hydraulic pressure in terms of responsiveness and precision, when the control content is switched in stages using a matrix of conditions and operations as in the present invention, the characteristics of pneumatic pressure, which is insensitive to changes in input compared to mechanical connections and hydraulic pressure, are less likely to cause vibration when the control content is switched, and can therefore be said to be preferable.

[0070] The above describes embodiments of the present invention with reference to the drawings, but the drilling machine of the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other modifications and changes to each component are permitted without departing from the spirit of the present invention, and the configurations of the above-mentioned embodiments can also be combined as appropriate. [Explanation of symbols]

[0071] 1 Drilling machine 2 Traveling cart 3. Cart body 4 Track Frame 5 Operator Cabin 5a Console 6. Boom 7 Guide Shell 8 Rock Drill 9. Striking mechanism 10 Rotation mechanism 11 Feeding mechanism 12 rods 12a Leading rod 13-bit 14 Rod Changer 15 Rod Magazine 16 Centralizer 17 Suction cap 18 Flushing mechanism 18a Pneumatic Modular 19 Dust Collector 20 control device 20 21 Control Unit 21a Program 22 Pilot Modular 23 Main valve 24 Feed Modular 25 Pressure Sensor Pp Hydraulic Pump Rt Receiver Tank P measurement value P1 Setting threshold P0 reference threshold P0+a Adjustment Threshold P0+b adjustment threshold P2 setting reference value dp Increased pressure per rod N Number of rods a, b adjustment value C Loop Count X loop limit n1~n4 setting time R Bedrock BH blast hole HR hard rock SR soft rock FZ shatter zone CL clay layer

Claims

1. A control device for a drilling machine equipped with a striking mechanism, a rotating mechanism, a feeding mechanism, and a flushing mechanism, a pressure sensor for measuring a flushing pressure, which is the pressure of the compressed air discharged by the flushing mechanism; and a drilling condition setting means for setting the operation of each mechanism, Each of the mechanisms is set with three or less types of operation patterns, Furthermore, at least four types of control levels are set by assigning one of the operation patterns to each of the mechanisms, including a normal control level for normal drilling, and a first control level, a second control level, and a third control level that are applied when the appropriate drilling conditions are different from those for normal drilling, A control device for a drilling machine, characterized in that the drilling condition setting means sets the operation of each of the mechanisms by selecting the control level based only on the flushing pressure.

2. 2. The control device for a drilling machine according to claim 1, wherein the operating patterns of the impact mechanism are three types: a normal drilling mode, a countersinking drilling mode, and a stop mode after countersinking, which stops operation after a predetermined time in the countersinking drilling mode.

3. 3. The control device for a drilling machine according to claim 1 or 2, wherein the operation pattern of the rotation mechanism is of two types: a normal speed rotation mode and a high speed rotation mode in which the rotation mechanism is rotated at a higher speed than the normal speed rotation mode.

4. 3. The control device for a drilling machine according to claim 1, wherein the operation patterns of the feed mechanism include three types: a normal feed mode, a feed stop mode, and a feed reverse mode.

5. 3. The control device for a drilling machine according to claim 1, wherein the operation patterns of the flushing mechanism include two types: a weak flushing mode and a strong flushing mode.

6. 3. The control device for a drilling machine according to claim 1, wherein the pressure sensor is detachable from the drilling machine.

7. A drilling machine comprising the control device for a drilling machine according to claim 1.

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