Drilling control device, drilling machine, and method for controlling drilling machine

Abstract

To appropriately determine the landing of a hammer grab in both cases where it is necessary to take into consideration water in a casing during drilling work and where it is not necessary to take into consideration water in a casing.SOLUTION: A drilling control device includes a height detector for acquiring height information correlating with the height of a hammer grab 10, a load value detector for acquiring a load value correlating with the weight of the hammer grab 10, and a controller 101 for determining whether the hammer grab 10 has landed. When the landing determination takes into account water in a casing 11, the controller 101 determines whether the hammer grab 10 has landed using the height information, and when the landing determination does not take into account water in the casing 11, it determines whether the hammer grab 10 has landed using the load value.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a technique for controlling an excavating machine in an excavation operation using a hammer grab. [Background technology]

[0002] Conventionally, an excavation machine equipped with a hammer grab is known (for example, Patent Document 1). The hammer grab is an attachment used in hammer grab work using an all-casing construction method. This hammer grab work includes an excavation work for excavating soil and sand inside a casing (a cylindrical member) pushed into the ground, and an earth removal work for discharging the soil and sand excavated in this excavation work outside the casing. In the excavation work, the wire rope that suspends the hammer grab is unwound from the winch drum to drop the hammer grab to the bottom inside the casing, thereby excavating the soil and sand inside the casing. In this excavation work, for example, by allowing the hammer grab to fall freely inside the casing, the cycle time of the excavation work can be shortened, and the impact force when the hammer grab lands can be used to efficiently excavate the bottom. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-163885 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the hammer grab lands on the bottom at a high falling speed, the hammer grab stops suddenly at the bottom while the winch drum continues to rotate due to inertia, resulting in over-releasing, a state in which the wire rope is excessively reeled out from the winch drum. In order to prevent such over-releasing from occurring, the operator must apply the brakes (brake pedal operation) after the hammer grab lands to stop the rotation of the winch drum. However, since the excavation work is performed in a situation where the operator cannot visually check the hammer grab inside the casing, it is difficult for the operator to apply the brakes appropriately in response to the landing of the hammer grab. Therefore, it is desirable to develop a control device that can appropriately determine the landing of the hammer grab.

[0005] In addition, the underground conditions where the excavation work is performed are different for each work site. Specifically, the casing pushed into the ground may or may not contain water such as groundwater. However, the control device described in Patent Document 1 does not take into account the water in the casing, and therefore may not be able to properly determine the landing of the hammer grab. [Means for solving the problem]

[0006] The present disclosure aims to provide an excavation control device, an excavation machine, and a control method for an excavation machine that can appropriately determine the landing of a hammer grab in both cases where water in a casing needs to be taken into consideration during excavation operations and cases where water in the casing does not need to be taken into consideration.

[0007] The excavation control device according to the first aspect is an excavation control device for an excavation machine that performs excavation work in which a wire rope suspending a hammer grab is unwound from a winch drum to drop the hammer grab to the bottom inside a cylindrical casing, and is equipped with a height detector for acquiring height information correlating with the height of the hammer grab, a load value detector for acquiring a load value correlating with the weight of the hammer grab, and a controller for determining whether the hammer grab has landed, and when the landing determination takes water inside the casing into consideration, the controller determines whether the hammer grab has landed using the height information, and when the landing determination does not take water inside the casing into consideration, the controller determines whether the hammer grab has landed using the load value.

[0008] In the drilling control device of the first aspect, the controller makes a landing judgment appropriate for both the case where water in the casing is taken into account and the case where water in the casing is not taken into account, so that in either case, the controller can make an appropriate landing judgment for the hammer grab.

[0009] In the second aspect, the excavation control device according to the first aspect preferably further includes the following feature. That is, the excavation control device according to the second aspect preferably further includes a water information provider that provides the controller with water information, which is information about water in the casing, and the controller preferably sets the landing determination mode to a mode that takes into account water in the casing (water consideration mode) or a mode that does not take into account water in the casing (non-consideration mode) based on the water information. In this second aspect, the controller can set the landing determination mode to either the water consideration mode or the non-consideration mode based on the water information provided by the water information provider. Then, when the landing determination mode is set to the water consideration mode, the controller determines whether or not the hammer grab has landed using the height information, and when the landing determination mode is set to the non-consideration mode, the controller determines whether or not the hammer grab has landed using the load value.

[0010] The third aspect is preferably the excavation control device according to the first or second aspect, further comprising the following feature. That is, in the excavation control device according to the third aspect, when the water in the casing is not taken into consideration in the landing judgment, the controller preferably judges whether the hammer grab has landed or not using both the load value and the height information. In this third aspect, the controller can judge the landing of the hammer grab more appropriately than when judging the landing of the hammer grab using only the load value. Specifically, during the time period from when the hammer grab starts to fall in an excavation operation to when the hammer grab lands, the load value detected by the load value detector may temporarily decrease in the time period immediately after the start of the fall. Since the hammer grab is in a relatively high position in this time period, even if a temporary decrease in the load value occurs in the time period immediately after the start of the fall, the controller can distinguish between the temporary decrease in the load value and the decrease in the load value caused by the landing of the hammer grab by using the height information. Therefore, when the controller does not take water inside the casing into account in the landing judgment, the controller can more appropriately judge the landing of the hammer grab by using the load value as the main indicator for the landing judgment and the height information as a secondary indicator for the landing judgment.

[0011] When the controller determines that the hammer grab has landed, it may notify the operator of the determination result, and when the operator is notified of the determination result, the operator may perform a brake operation (brake pedal operation) to stop the rotation of the winch drum. However, as in the following fourth aspect, it is preferable that the control for braking the winch drum to stop the rotation of the winch drum is automatically performed by the controller. The fourth aspect is preferably an excavation control device according to any one of the first to third aspects, further comprising the following feature. That is, when the controller determines that the hammer grab has landed, it is preferable that the controller performs a brake control (landing brake control) to stop the rotation of the winch drum. In this fourth aspect, since the controller not only determines that the hammer grab has landed but also performs landing brake control, it is possible to further reduce the burden on the operator while suppressing the occurrence of over-reeling, which is a state in which the wire rope is excessively reeled out from the winch drum after the hammer grab has landed.

[0012] A fifth aspect may further include the following feature in the excavation control device according to any one of the first to fourth aspects. That is, in the excavation control device according to the fifth aspect, the height detector may include a drum rotation detector for detecting an amount of rotation of the winch drum, and the controller may calculate the height of the hammer grab using the amount of rotation. In this fifth aspect, the controller can calculate the height of the hammer grab using the amount of rotation of the winch drum (an example of height information) that correlates with the height of the hammer grab.

[0013] A sixth aspect is preferably the excavation control device according to the fifth aspect, further comprising the following features. That is, in the excavation control device according to the sixth aspect, when the water in the casing is taken into consideration in the landing determination, the controller preferably performs control to adjust the braking force on the winch drum so that the wire rope is prevented from slackening when the hammergrab falls through the water. In this sixth aspect, when the controller calculates the height of the hammergrab using the rotation amount, the controller can prevent an error in the calculated value caused by the slackness of the wire rope from increasing, so that the controller can more appropriately determine whether the hammergrab has landed. Specifically, for example, the controller may perform control to adjust the braking force on the winch drum so that the slack state of the wire rope falls within a predetermined slack tolerance range when the hammergrab falls through the water. Also, the controller may perform control to apply the brakes to the winch drum with a predetermined braking force when the hammergrab falls through the water, or may perform control to apply the brakes to the winch drum at a predetermined cycle.

[0014] The seventh aspect may further include the following feature in the excavation control device according to the fifth or sixth aspect. That is, in the excavation control device according to the seventh aspect, it is preferable that the controller determines the ground clearance height, which is the height position when the hammer grab leaves the bottom, based on a load value change in which the load value increases as the wire rope is wound around the winch drum from a state in which the hammer grab is in contact with the bottom, and calculates the height of the hammer grab using the ground clearance height and the amount of rotation. When excavation work is performed repeatedly, the relative position of the bottom with respect to the ground surface gradually shifts downward with each excavation work. Even in such a case, in the seventh aspect, the controller can update the ground clearance height, which is the height position when the hammer grab leaves the bottom, based on the load value change before the next excavation work, so that the height position of the hammer grab in the next excavation work can be obtained more accurately.

[0015] An eighth aspect is preferably the excavation control device according to any one of the first to seventh aspects, further comprising the following feature. That is, in the excavation control device according to the eighth aspect, when the water in the casing is not taken into consideration in the landing judgment, the controller preferably performs control to adjust the braking force on the winch drum so that the falling speed of the hammergrab falls within a predetermined speed tolerance range (impact force adjustment control). In this eighth aspect, for example, even if the falling distance of the hammergrab (the distance from the falling start height position to the bottom) is long during excavation work and the falling speed is likely to be high, the falling speed of the hammergrab can be prevented from becoming excessively high, and therefore damage to the hammergrab caused by the impact when the hammergrab lands can be prevented.

[0016] A ninth aspect is preferably the excavation control device according to any one of the first to eighth aspects, further comprising the following feature. That is, the excavation control device according to the ninth aspect preferably further comprises a weight setting input device that receives an input from an operator, and the controller sets the weight of the hammer grab using the load value at the time when the weight setting input device receives the input. In this ninth aspect, when the operator wants to set (update) the weight of the hammer grab, he or she can set the weight of the hammer grab in the controller by making a predetermined input to the weight setting input device.

[0017] A tenth aspect is preferably the excavation control device according to any one of the first to ninth aspects, further comprising the following feature. That is, in the excavation control device according to the tenth aspect, it is preferable that the controller determines the landing timing of the hammergrab and the ground-leaving timing of the hammergrab from the bottom by using the load value acquired by the load value detector, and acquires an initial value of the height of the hammergrab and a characteristic related to a delay of the load value detector by using a relative position of the height position of the hammergrab at the landing timing with respect to a reference height position, a relative position of the height position of the hammergrab at the ground-leaving timing with respect to the reference height position, and a change speed of the height of the hammergrab. In this tenth aspect, the controller can acquire the initial value of the height of the hammergrab and the characteristic related to a delay of the load value detector. Also, the controller can more accurately calculate the height of the hammergrab by taking into account the characteristic related to a delay of the load value detector.

[0018] An eleventh aspect may further include the following feature in the excavation control device according to any one of the first to ninth aspects. That is, in the excavation control device according to the eleventh aspect, the controller may determine the landing timing of the hammergrab and the ground separation timing of the hammergrab leaving the bottom by using the load value acquired by the load value detector, and may acquire an error caused by the wire rope length and a characteristic related to a delay of the load value detector by using a relative position of the height position of the hammergrab at the landing timing with respect to a reference height position, a relative position of the height position of the hammergrab at the ground separation timing with respect to the reference height position, and a changing speed of the height of the hammergrab.

[0019] The excavation machine according to a twelfth aspect includes a lower body, an upper rotating body rotatably supported on the lower body, a hoisting member supported on the upper rotating body so as to be capable of being raised and lowered, the wire rope, the winch drum, the hammergrab, and the excavation control device according to any one of the first to eleventh aspects. In the excavation machine according to the twelfth aspect, the controller performs a landing judgment appropriate for each of a case in which water in the casing is taken into consideration and a case in which water in the casing is not taken into consideration, so that the controller can appropriately perform the landing judgment of the hammergrab in either case.

[0020] A thirteenth aspect is preferably the excavation machine according to the twelfth aspect, further comprising the following features. That is, in the excavation machine according to the thirteenth aspect, the excavation control device preferably comprises a swivel angle detector for acquiring the swivel angle of the upper rotating body relative to the lower body, and a hoisting angle detector for acquiring the hoisting angle, which is the angle of the hoisting member relative to the upper rotating body, and the controller preferably determines whether the swivel angle and the hoisting angle are within an allowable operation range allowed in the excavation work. Since the hammergrab is supported by the hoisting member via a wire rope, the swivel angle and the hoisting angle are correlated with the position of the hammergrab. Therefore, in this thirteenth aspect, the controller can indirectly determine whether the hammergrab is located in a position suitable for excavation work, i.e., in a position corresponding to the casing, by using the swivel angle and the hoisting angle.

[0021] A 14th aspect is preferably the excavation machine according to the 13th aspect, further comprising the following feature. That is, in the excavation machine according to the 14th aspect, it is preferable that the controller allows automatic control of at least a part of the excavation operation when the swing angle and the hoisting angle are within the permissible operation ranges, and suspends execution of the automatic control when the swing angle and the hoisting angle are not within the permissible operation ranges. In this 14th aspect, the controller can decide whether to allow or suspend the automatic control based on a result of determining whether the swing angle and the hoisting angle are within the permissible operation ranges.

[0022] A fifteenth aspect is a method for controlling an excavating machine that performs excavation work in which a wire rope for suspending a hammergrab is unwound from a winch drum to drop the hammergrab to the bottom of a cylindrical casing, comprising: determining whether the hammergrab has landed using height information correlating with the height of the hammergrab when water in the casing is taken into consideration in the landing judgment of the hammergrab; and determining whether the hammergrab has landed using a load value correlating with the weight of the hammergrab when water in the casing is not taken into consideration in the landing judgment. In the method for controlling an excavating machine according to the fifteenth aspect, a landing judgment appropriate for each of the cases of taking water in the casing into consideration and not taking water in the casing into consideration is performed, so that the landing judgment of the hammergrab can be appropriately performed in either case. Effect of the Invention

[0023] As described above, according to the present disclosure, an excavation control device, an excavation machine, and a control method for an excavation machine are provided that can appropriately determine the landing of the hammer grab in both cases where it is necessary to take water into account in the casing during excavation work and cases where it is not necessary to take water into account in the casing. [Brief description of the drawings]

[0024] [Figure 1] 1 is a side view showing an excavation machine equipped with an excavation control device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram showing a hydraulic circuit of the excavation machine. [Diagram 3] FIG. 2 is a block diagram showing a functional configuration of the excavation control device. [Figure 4] 4 is a flowchart showing an example of a calculation control operation performed by a controller of the excavation control device. [Diagram 5]FIG. 13 is a diagram showing an example of changes in the height of the hammer grab and the load value over time during excavation work when there is no need to take water into account inside the casing. [Figure 6] FIG. 13 is a diagram showing an example of changes in the height of the hammer grab and the load value over time during drilling operations when water in the casing needs to be taken into consideration. [Figure 7] 6 is a flowchart showing another example of the arithmetic control operation performed by a controller of the excavation control device. [Figure 8] 13 is a diagram for explaining a method of acquiring an initial value of the height of the hammer grab and characteristics related to a delay of a load value detector. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] A preferred embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 shows an excavation machine 200 according to an embodiment. Fig. 2 is a diagram showing an example of a hydraulic circuit provided in the excavation machine 200. Fig. 3 is a block diagram showing an example of a functional configuration of an excavation control device 100 according to an embodiment.

[0026] The excavation machine 200 according to this embodiment is a crane. The excavation machine 200 can perform a hammer grab operation using an all-casing construction method. This hammer grab operation includes an excavation operation in which the hammer grab 10 is dropped to a bottom 12 in a casing 11, which is a cylindrical member pushed into the ground (underground) as the work target, to excavate soil and sand inside the casing 11, as shown in FIG. 1, and a discharge operation in which the hammer grab 10 holding the excavated soil and sand are raised to discharge the soil and sand outside the casing 11. The excavation machine 200 includes an excavation control device 100 (see FIG. 3) that controls the operation of the excavation machine 200.

[0027] 3, the excavation control device 100 according to this embodiment includes a controller 101, a drum rotation detector 102 that detects the amount of rotation of the winch drum that correlates with the height of the hammer grab 10, and a load value detector 108 that acquires a load value that correlates with the weight of the hammer grab 10. The drum rotation detector 102 is an example of a height detector, and the amount of rotation of the winch drum is an example of height information that correlates with the height of the hammer grab 10.

[0028] The controller 101 performs a landing judgment of the hammer grab 10 falling inside the casing 11. When the water inside the casing 11 is taken into consideration in the landing judgment, the controller 101 performs a landing judgment control that judges whether the hammer grab 10 has landed or not by using the rotation amount (the height information), and when the water inside the casing 11 is not taken into consideration in the landing judgment, the controller 101 performs a landing judgment control that judges whether the hammer grab 10 has landed or not by using the load value. In this excavation control device 100, the controller 101 performs a landing judgment appropriate for each of the cases where the water inside the casing 11 is taken into consideration and where the water inside the casing 11 is not taken into consideration, so that the controller 101 can appropriately perform the landing judgment of the hammer grab 10 in either case.

[0029] Specifically, when it is not necessary to take water in the casing 11 into consideration in determining whether the hammer grab 10 has landed, for example, when there is no water in the casing 11 or when the water level is low even if water is in the casing 11, the hammer grab 10 falling inside the casing 11 during drilling operation encounters almost no resistance from the water before it lands on the bottom 12, so the falling speed of the hammer grab 10 immediately before it lands on the bottom 12 becomes relatively large. In this case, the change in the load value between immediately before and immediately after the hammer grab 10 lands becomes large, so the load value detected by the load value detector 108 is useful as a main index for determining whether the hammer grab 10 has landed, and therefore the controller 101 can appropriately determine whether the hammer grab 10 has landed by using the load value.

[0030] On the other hand, when it is necessary to take water in the casing 11 into consideration in determining whether the hammer grab 10 has landed, for example, when water is stored in the casing 11 and the water level is relatively high, the hammer grab 10 falling inside the casing 11 during drilling work will land on the water before landing on the bottom 12, descend through the water, and continue to encounter resistance from the water until it lands on the bottom 12, so that the falling speed of the hammer grab 10 just before it lands on the bottom 12 will be smaller than when there is no water stored in the casing. In this case, the amount of change in the load value between just before and just after the hammer grab 10 lands will also be small, so it is not preferable to use the load value detected by the load value detector as the main index for determining whether the hammer grab 10 has landed. On the other hand, the members constituting the main parts of the hammergrab 10 are generally formed using materials such as metals whose specific gravity (specific gravity based on water) is considerably greater than 1, so even when the hammergrab 10 encounters water resistance as it descends through the water, the height of the hammergrab 10 decreases steadily until it lands. Therefore, when water has accumulated in the casing 11 and the water level is relatively high, height information correlating with the height of the hammergrab 10 is useful as a main index for determining whether the hammergrab 10 has landed, and therefore the controller 101 can appropriately determine whether the hammergrab 10 has landed by using the height information.

[0031] The excavation control device 100 according to this embodiment further includes a water information provider 91 (see FIG. 2) that provides water information, which is information related to the water in the casing 11, to the controller 101.

[0032] The controller 101 sets the landing determination mode to a mode that takes into account water in the casing 11 (water consideration mode) or a mode that does not take into account water in the casing 11 (non-consideration mode) based on the water information input from the water information provider 91. When the landing determination mode is set to the water consideration mode, the controller 101 determines whether or not the hammergrab 10 has landed using the height information, and when the landing determination mode is set to the non-consideration mode, the controller 101 determines whether or not the hammergrab 10 has landed using the load value.

[0033] The water information provider 91 may include the following specific examples. The water information provider 91 may include a water information input device capable of receiving input from an operator. In this case, the input from the operator may include an input for specifying that it is necessary to consider water in the casing 11 in the landing determination, and an input for specifying that it is not necessary to consider water in the casing 11 in the landing determination. The operator may grasp the water level in the casing 11 based on a preliminary survey such as a boring survey conducted before the drilling work. For example, when the water level in the casing 11 is zero or a relatively small value, the operator may provide an input to the water information input device to cause the controller 101 to execute a landing determination that does not consider water in the casing 11, and when the water level in the casing 11 is a relatively large value, the operator may provide an input to the water information input device to cause the controller 101 to execute a landing determination that considers water in the casing 11. The input may be, for example, an input to select whether or not to consider water in the casing 11, an input of the presence or absence of water, or an input of the water level. The water information input device outputs water information, which is information related to the input by the operator, to the controller 101, and the controller 101 can set the landing determination mode to a water consideration mode or a non-consideration mode based on the water information input from the water information input device.

[0034] Furthermore, the water information provider 91 may include a water level sensor capable of detecting the water level inside the casing 11. In this case, the water level sensor outputs water information, which is information related to the water level, to the controller 101, and the controller 101 can set the landing determination mode to a water consideration mode or a non-consideration mode based on the water information input from the water level sensor.

[0035] The main features of the excavation control device 100, the excavation machine 200, and the control method for the excavation machine 200 according to this embodiment have been described above.

[0036] Below, the excavation control device 100, the excavation machine 200, and the control method of the excavation machine 200 will be described in further detail using specific examples, but the excavation control device, the excavation machine, and the control method of the excavation machine in this disclosure are not limited to the specific examples below.

[0037] As shown in FIG. 1, the excavating machine 200 comprises a lower body 201, an upper rotating body 202 rotatably supported on the lower body 201, a hoisting member 204 supported on the upper rotating body 202 so as to be capable of being raised and lowered, a plurality of winches, and a hammer grab 10.

[0038] The lower body 201 is equipped with a traveling device such as a crawler traveling device and is configured to be self-propelled. However, the lower body only needs to support the upper rotating body 202 so that it can rotate, and may be configured as a structure such as a support base that is not self-propelled.

[0039] The upper rotating body 202 comprises a rotating frame 203 rotatably attached to the lower body 201, a cabin supported on the front part of the rotating frame 203, and a counterweight supported on the rear part of the rotating frame 203.

[0040] In this embodiment, the hoisting member 204 is composed of a boom supported on the revolving frame 203 so as to be capable of being hoisted. However, the hoisting member may include a boom and a jib (not shown) supported rotatably at the tip of the boom. A gantry 207 is erected on the revolving frame 203. A lower spreader 210 is disposed at the upper end of the gantry 207. One end of a guy line 208 is connected to the tip of the hoisting member 204, and an upper spreader 209 is connected to the other end of the guy line 208. The lower spreader 210 and the upper spreader 209 are disposed at a distance from each other. A hoisting wire rope 211 is wound around the lower spreader 210 and the upper spreader 209.

[0041] The multiple winches include a main winch WC1, an auxiliary winch WC2, and a hoisting winch WC3. In this embodiment, the multiple winches are supported by the upper rotating body 202, but at least one of the multiple winches may be supported by the hoisting member 204, for example.

[0042] The hoisting winch WC3 has a hoisting winch drum DR3 around which the hoisting wire rope 211 is wound. The hoisting winch WC3 winds or unwinds the hoisting wire rope 211 to reduce or increase the distance between the upper spreader 209 and the lower spreader 210. As the distance decreases or increases, the hoisting member 204 is hoisted.

[0043] The main winch WC1 is a device for winding and unwinding the main winding wire rope R1. The auxiliary winch WC2 is a device for winding and unwinding the auxiliary winding wire rope R2.

[0044] 1 and 2, the main winch WC1 has a main winding drum DR1, which is a winch drum around which the main winding wire rope R1 is wound, a main winding motor 34 that drives the main winding drum DR1, a main winding clutch brake 48, and a reducer 47. The main winding drum DR1 is an example of a winch drum in the present disclosure, and the main winding wire rope R1 is an example of a wire rope in the present disclosure.

[0045] The configuration of the auxiliary winch WC2 is substantially the same as that of the main winch WC1. Therefore, in the hydraulic circuit of Fig. 2, the configuration of the main winch WC1 is representatively depicted, and the configuration of the auxiliary winch WC2 is omitted. The auxiliary winch WC2 has an auxiliary winding drum DR2 around which the auxiliary winding wire rope R2 is wound, an auxiliary winding motor 35 that drives the auxiliary winding drum DR2, an auxiliary winding clutch brake 49, and a reducer 47.

[0046] As shown in Fig. 1, the hammer grab 10 includes a body 10A, a glove 10B, and a crown 10C. The glove 10B is attached to the lower part of the body 10A so as to be openable and closable. The crown 10C is a member for switching the glove 10B between an open state and a closed state. In the specific example of Fig. 1, the crown 10C is disposed above the body 10A.

[0047] A main winding point sheave 205 and an auxiliary winding point sheave 206 are attached to the tip of the hoisting member 204. The main winding wire rope R1 is wound around the main winding point sheave 205 and hangs down from the main winding point sheave 205. The auxiliary winding wire rope R2 is wound around the auxiliary winding point sheave 206 and hangs down from the auxiliary winding point sheave 206. The main winding wire rope R1 is a wire rope for suspending the body 10A and grab 10B of the hammer grabbing machine 10, and the auxiliary winding wire rope R2 is a wire rope for suspending the crown 10C.

[0048] The hammer grab 10 operates, for example, as follows. First, the main winding wire rope R1 is paid out from the main winding drum DR1, and the hammer grab 10 falls in the casing 11 to the bottom 12 of the ground, which is the work target (excavation target). The hammer grab 10 excavates the soil at the bottom 12 by utilizing the energy accompanying the fall. After that, the main winding wire rope R1 is wound up by the main winding winch WC1 and the grab 10B is closed, so that the soil is held in the grab 10B. Then, the main winding wire rope R1 is further wound up by the main winding winch WC1, and the hammer grab 10 rises and is taken out of the casing 11. The upper rotating body 202 rotates to move the hammer grab 10 above a predetermined position, and then the auxiliary winding wire rope R2 is paid out from the auxiliary winding drum DR2 of the auxiliary winch WC2. Then, the crown 10C fits into the body 10A of the hammer grab 10. As a result, the body 10A and crown 10C are suspended from the auxiliary hoisting wire rope R2, and the grab 10B is ready to be opened. In this state, the main hoisting wire rope R1 is paid out from the main hoisting drum DR1 of the main hoisting winch WC1, opening the grab 10B and discharging the soil from the hammer grab 10 to the specified position.

[0049] Each of the main winding motor 34 and the auxiliary winding motor 35 is a hydraulic motor and is connected to the hydraulic pump 31. The main winding motor 34 operates to rotate the main winding drum DR1 in either the pay-out direction or the winding direction by receiving a supply of hydraulic oil discharged from the hydraulic pump 31. Similarly, the auxiliary winding motor 35 operates to rotate the auxiliary winding drum DR2 in either the pay-out direction or the winding direction by receiving a supply of hydraulic oil discharged from the hydraulic pump 31. The hydraulic pump 31 is driven by a drive source such as an engine or an electric motor (not shown).

[0050] The reducer 47 of the main winch WC1 reduces the rotation speed of the main winding motor 34 and transmits power (rotational force) from the main winding motor 34 to the main winding drum DR1. The reducer 47 of the auxiliary winch WC2 reduces the rotation speed of the auxiliary winding motor 35 and transmits power (rotational force) from the auxiliary winding motor 35 to the auxiliary winding drum DR2. Each of these reducers 47 has, for example, a planetary gear mechanism.

[0051] The main winding clutch brake 48 can be switched between a connected state and a free state. The main winding clutch brake 48 can adjust the degree of coupling between the main winding motor 34 and the main winding drum DR1 between the connected state and the free state.

[0052] The connected state is a state in which the power of the main winding motor 34 can be transmitted to the main winding drum DR1. In other words, the connected state is a state in which the main winding wire rope R1 can be unwound and wound by the power of the main winding motor 34. Therefore, when the main winding motor 34 operates in the connected state, the power of the main winding motor 34 is transmitted to the main winding drum DR1 via the reducer 47, causing the main winding drum DR1 to rotate. When the main winding drum DR1 rotates, the main winding wire rope R1 is unwound or wound.

[0053] The free state is a state in which the main hoisting wire rope R1 can be unwound from the main hoisting drum DR1 by the weight of the hammer grab 10. In other words, the free state is a state in which the main hoisting wire rope R1 can be unwound from the main hoisting drum DR1 by the tension of the main hoisting wire rope R1, that is, a state in which the hammer grab 10 can freely fall. Therefore, in the free state, the main hoisting wire rope R1 can be unwound from the main hoisting drum DR1 even if the main hoisting motor 34 is not operated in the unwounding direction of the main hoisting wire rope R1.

[0054] Similarly, the auxiliary winding clutch brake 49 can be switched between a connected state and a free state, and the auxiliary winding clutch brake 49 can adjust the degree of coupling between the auxiliary winding motor 35 and the auxiliary winding drum DR2 between the connected state and the free state.

[0055] The connected state is a state in which the power of the auxiliary winding motor 35 can be transmitted to the auxiliary winding drum DR2. In other words, the connected state is a state in which the auxiliary winding wire rope R2 can be unwound and wound by the power of the auxiliary winding motor 35. Therefore, when the auxiliary winding motor 35 operates in the connected state, the power of the auxiliary winding motor 35 is transmitted to the auxiliary winding drum DR2 via the reducer 47, causing the auxiliary winding drum DR2 to rotate. When the auxiliary winding drum DR2 rotates, the auxiliary winding wire rope R2 is unwound or wound.

[0056] The free state is a state in which the auxiliary hoisting wire rope R2 can be unwound from the auxiliary hoist drum DR2 by the weight of the hammer grab 10. In other words, the free state is a state in which the auxiliary hoisting wire rope R2 can be unwound from the auxiliary hoist drum DR2 by the tension of the auxiliary hoisting wire rope R2. Therefore, in the free state, the auxiliary hoisting wire rope R2 can be unwound from the auxiliary hoist drum DR2 without operating the auxiliary hoist motor 35 in the unwound direction of the auxiliary hoisting wire rope R2.

[0057] The main winding clutch brake 48 is capable of applying a braking force to the main winding drum DR1, that is, of applying a brake to the main winding drum DR1. The main winding clutch brake 48 is capable of adjusting the braking force applied to the main winding drum DR1.

[0058] Similarly, the auxiliary winding clutch brake 49 is capable of applying a braking force to the auxiliary winding drum DR2, that is, of braking the auxiliary winding drum DR2. The auxiliary winding clutch brake 49 is capable of adjusting the braking force applied to the auxiliary winding drum DR2.

[0059] In this embodiment, each of the main winding clutch brake 48 and the auxiliary winding clutch brake 49 is a so-called wet brake, and includes a case 40, a piston 42 that is displaced relative to the case 40 by hydraulic pressure applied from the pilot pump 36, and a plurality of brake discs 41 (a plurality of clutch plates). Each of the plurality of brake discs 41 is, for example, a friction plate immersed in hydraulic oil.

[0060] The brake discs 41 can be switched between a state in which the brake discs 41 are in contact with one another and a state in which the brake discs 41 are separated from one another by the operation of the piston 42. Each of the main winding clutch brake 48 and the auxiliary winding clutch brake 49 is in the free state when the brake discs 41 are separated from one another. When the main winding clutch brake 48 is in the free state, the hammer grab 10 is allowed to descend (free fall) by its own weight. Also, each of the main winding clutch brake 48 and the auxiliary winding clutch brake 49 is in the connected state when the brake discs 41 are in contact with one another.

[0061] More specifically, each of the main winding clutch brake 48 and the auxiliary winding clutch brake 49 includes a spring 46. A pair of oil chambers 43, 44 are formed in each of the cases 40 of the main winding clutch brake 48 and the auxiliary winding clutch brake 49. The piston 42 has a partition 45 that separates the pair of oil chambers 43, 44. The spring 46 biases the piston 42 in a direction in which the multiple brake discs 41 approach each other.

[0062] For example, when the hydraulic pressure applied from the pilot pump 36 to the pair of oil chambers 43, 44 is the same, the piston 42 receiving the urging force of the spring 46 pushes the brake discs 41, so that the brake discs 41 come into contact with each other. When the hydraulic pressure applied from the pilot pump 36 to one oil chamber 44 becomes greater than the hydraulic pressure applied to the other oil chamber 43 by a predetermined amount or more, the brake discs 41 come into a state of being separated from each other. That is, in each of the main winding clutch brake 48 and the auxiliary winding clutch brake 49, the degree of contact of the brake discs 41 changes depending on the difference between the hydraulic pressure applied to the oil chamber 44 and the hydraulic pressure applied to the oil chamber 43. Therefore, the main winding clutch brake 48 can adjust the braking force applied to the main winding drum DR1 depending on the difference between the oil chamber 43 and the oil chamber 44, and the auxiliary winding clutch brake 49 can adjust the braking force applied to the auxiliary winding drum DR2 depending on the difference between the oil chamber 43 and the oil chamber 44.

[0063] As shown in Figures 2 and 3, the excavation control device 100 includes a plurality of operating devices, a plurality of valves, a controller 101, a drum rotation detector 102, a lever input detector 103, a rotation angle detector 104, a lifting angle detector 105, a pedal input detector 106, a monitor switch 107, a load value detector 108, and a monitor 115.

[0064] The multiple operating devices include a main winch operating device 51, an auxiliary winch operating device 53, a main winch brake operating device 52, and an auxiliary winch brake operating device 54.

[0065] The main winch operator 51 includes a main winch lever 51A to which the operator inputs the main winch operation. The lever input detector 103 detects the direction and amount of the main winch operation input to the main winch lever 51A, and inputs the detection result to the controller 101. The main winch operation includes a winding operation for winding up the main winch wire rope R1, and a reeling operation for reeling out the main winch wire rope R1.

[0066] The auxiliary winch operator 53 includes an auxiliary winch lever 53A to which an auxiliary winch operation by an operator is input. The lever input detector 103 detects the direction and amount of the auxiliary winch operation input to the auxiliary winch lever 53A, and inputs the detection result to the controller 101.

[0067] The main winding brake operating device 52 includes a main winding pedal 52A to which the main winding brake operation by the operator is input. The pedal input detector 106 detects the amount of main winding brake operation input to the main winding pedal 52A, and inputs the detection result to the controller 101.

[0068] The auxiliary brake operation device 54 includes an auxiliary pedal 54A to which an auxiliary brake operation by an operator is input. The pedal input detector 106 detects the amount of auxiliary brake operation input to the auxiliary pedal 54A and inputs the detection result to the controller 101.

[0069] The valves include a main winding valve group for controlling the operation of the main winding drum DR1, and an auxiliary winding valve group for controlling the operation of the auxiliary winding drum DR2. As shown in Fig. 2, the main winding valve group includes the main winding control valve 32, a payout proportional valve 61A, a take-up proportional valve 61B, a main winding brake control proportional valve 62, a main winding pedal proportional valve 67, a brake system change-over valve 65, a mode change-over valve 66, and an emergency brake change-over valve 69. The configuration of the auxiliary winding valve group is substantially the same as that of the main winding valve group. Therefore, in the hydraulic circuit of Fig. 2, the main winding valve group is representatively illustrated, and the auxiliary winding valve group is omitted. The auxiliary winding valve group includes the auxiliary control valve 33, a payout proportional valve 63A, a take-up proportional valve 63B, an auxiliary brake control proportional valve 64, an auxiliary winding pedal proportional valve 68, a brake system change-over valve 65, a mode change-over valve 66, and an emergency brake change-over valve 69.

[0070] The main winding control valve 32 is interposed between the hydraulic pump 31 and the main winding motor 34, and the auxiliary winding control valve 33 is interposed between the hydraulic pump 31 and the auxiliary winding motor 35. Each of the main winding control valve 32 and the auxiliary winding control valve 33 has a pay-out pilot port and a take-up pilot port.

[0071] When pilot pressure is not applied to both pilot ports, the main winding control valve 32 is held in a neutral position to shut off the main winding motor 34 from the hydraulic pump 31. When pilot pressure is applied to the pay-out pilot port, the main winding control valve 32 opens to form an oil path for rotating the main winding motor 34 in the pay-out direction. When pilot pressure is applied to the winding pilot port, the main winding control valve 32 opens to form an oil path for rotating the main winding motor 34 in the winding direction.

[0072] Similarly, when pilot pressure is not applied to both pilot ports, the auxiliary winding control valve 33 is held in a neutral position to shut off the auxiliary winding motor 35 from the hydraulic pump 31. When pilot pressure is applied to the pay-out pilot port, the auxiliary winding control valve 33 opens to form an oil passage for rotating the auxiliary winding motor 35 in the pay-out direction. When pilot pressure is applied to the winding pilot port, the auxiliary winding control valve 33 opens to form an oil passage for rotating the auxiliary winding motor 35 in the winding direction.

[0073] The payout proportional valve 61A is interposed between a hydraulic power source (not shown) and a payout pilot port of the main winding control valve 32. The payout proportional valve 61A is, for example, an electromagnetic proportional valve. The payout proportional valve 61A generates a pilot pressure, which is a secondary pressure, according to a main winding payout command input from the controller 101, and inputs the pilot pressure to the payout pilot port of the main winding control valve 32. As a result, the opening of the main winding control valve 32 is adjusted to a magnitude according to the main winding payout command, and the main winding motor 34 rotates in the payout direction at a speed according to the pilot pressure.

[0074] The winding proportional valve 61B is interposed between the hydraulic power source and a winding pilot port of the main winding control valve 32. The winding proportional valve 61B is, for example, an electromagnetic proportional valve. The winding proportional valve 61B generates a pilot pressure, which is a secondary pressure, according to a main winding command input from the controller 101, and inputs the pilot pressure to the winding pilot port of the main winding control valve 32. As a result, the opening of the main winding control valve 32 is adjusted to a magnitude according to the main winding command, and the main winding motor 34 rotates in the winding direction at a speed according to the pilot pressure.

[0075] Similarly, the payout proportional valve 63A is interposed between the hydraulic power source and the payout pilot port of the auxiliary winding control valve 33. The payout proportional valve 63A is, for example, an electromagnetic proportional valve. The payout proportional valve 63A generates a pilot pressure, which is a secondary pressure, in response to an auxiliary winding payout command input from the controller 101, and inputs the pilot pressure to the payout pilot port of the auxiliary winding control valve 33. As a result, the opening of the auxiliary winding control valve 33 is adjusted to a magnitude in response to the auxiliary winding payout command, and the auxiliary winding motor 35 rotates in the payout direction at a speed in response to the pilot pressure.

[0076] The winding proportional valve 63B is interposed between the hydraulic source and the winding pilot port of the auxiliary winding control valve 33. The winding proportional valve 63B is, for example, an electromagnetic proportional valve. The winding proportional valve 63B generates a pilot pressure, which is a secondary pressure, according to an auxiliary winding command input from the controller 101, and inputs the pilot pressure to the winding pilot port of the auxiliary winding control valve 33. As a result, the opening of the auxiliary winding control valve 33 is adjusted to a value according to the auxiliary winding command, and the auxiliary winding motor 35 rotates in the winding direction at a speed according to the pilot pressure. The hydraulic source may be the pilot pump 36, or may be a pump separate from the pilot pump 36.

[0077] The main winding brake control proportional valve 62 is interposed between the pilot pump 36 and the main winding clutch brake 48. The main winding brake control proportional valve 62 is, for example, an electromagnetic proportional valve. The main winding brake control proportional valve 62 generates a secondary pressure (main winding pilot pressure) according to a main winding brake command input from the controller 101, and this secondary pressure is input to the oil chamber 43 of the main winding clutch brake 48. In other words, the main winding brake control proportional valve 62 can generate a braking force in the main winding clutch brake 48 according to the main winding brake command input from the controller 101.

[0078] Similarly, the auxiliary brake control proportional valve 64 is interposed between the pilot pump 36 and the auxiliary clutch brake 49. The auxiliary brake control proportional valve 64 is, for example, an electromagnetic proportional valve. The auxiliary brake control proportional valve 64 generates a secondary pressure (auxiliary pilot pressure) according to an auxiliary brake command input from the controller 101, and this secondary pressure is input to the oil chamber 43 of the auxiliary clutch brake 49. In other words, the auxiliary brake control proportional valve 64 can generate a braking force in the auxiliary clutch brake 49 according to the auxiliary brake command input from the controller 101.

[0079] The main winding pedal proportional valve 67 is interposed between the pilot pump 36 and the main winding clutch brake 48. The main winding pedal proportional valve 67 generates a secondary pressure (main winding pilot pressure) corresponding to the amount of main winding brake operation input to the main winding pedal 52A by the operator, and this secondary pressure is input to the oil chamber 43 of the main winding clutch brake 48. In other words, the main winding pedal proportional valve 67 can generate a braking force in the main winding clutch brake 48 corresponding to the amount of main winding brake operation input by the operator.

[0080] Similarly, the auxiliary pedal proportional valve 68 is interposed between the pilot pump 36 and the auxiliary clutch brake 49. The auxiliary pedal proportional valve 68 generates a secondary pressure (auxiliary pilot pressure) corresponding to the amount of auxiliary brake operation input to the auxiliary pedal 54A by the operator, and this secondary pressure is input to the oil chamber 43 of the auxiliary clutch brake 49. In other words, the auxiliary pedal proportional valve 68 can generate, in the auxiliary clutch brake 49, a braking force corresponding to the amount of auxiliary brake operation input by the operator.

[0081] The mode switching valve 66 is a switching valve for switching between a state in which a bypass oil passage is formed and a state in which a proportional valve oil passage is formed. The mode switching valve 66 is interposed between the brake system switching valve 65 and the main winding clutch brake 48.

[0082] The bypass oil passage is an oil passage through which the pilot pump 36 is connected to the oil chamber 43 of the main winding clutch brake 48, bypassing the main winding brake control proportional valve 62 and the main winding pedal proportional valve 67. In other words, the bypass oil passage is an oil passage through which the pilot pump 36 is connected to the oil chamber 43 of the main winding clutch brake 48 without passing through these proportional valves 62, 67.

[0083] The proportional valve oil passage is an oil passage that connects the pilot pump 36 to the oil chamber 43 of the main winding clutch brake 48 via either the main winding brake control proportional valve 62 or the main winding pedal proportional valve 67. The proportional valve oil passage includes a brake control proportional valve oil passage and a pedal proportional valve oil passage. The brake control proportional valve oil passage is an oil passage that connects the pilot pump 36 to the oil chamber 43 of the main winding clutch brake 48 via the main winding brake control proportional valve 62. The pedal proportional valve oil passage is an oil passage that connects the pilot pump 36 to the oil chamber 43 of the main winding clutch brake 48 via the main winding pedal proportional valve 67.

[0084] Specifically, for example, the mode switching valve 66 may be a two-position solenoid switching valve having a spool that can be switched between a bypass oil passage forming position (right position in FIG. 2) at which a bypass oil passage is formed and a proportional valve oil passage forming position (left position in FIG. 2) at which a proportional valve oil passage is formed in response to a command input from the controller 101. In the specific example shown in FIG. 2, when the solenoid of the mode switching valve 66 is in a non-excited state, the spool of the mode switching valve 66 is disposed at the bypass oil passage forming position, and when the solenoid of the mode switching valve 66 is in an excited state, the spool of the mode switching valve 66 is disposed at the proportional valve oil passage forming position. However, the structure of the mode switching valve 66 is not limited to this specific example. The mode switching valve 66 may be configured such that the spool is disposed at the bypass oil passage forming position when the solenoid is in an excited state, and the spool is disposed at the proportional valve oil passage forming position when the solenoid is in a non-excited state.

[0085] The brake system switching valve 65 is a switching valve for switching between a state in which the brake control proportional valve oil passage is formed and a state in which the pedal proportional valve oil passage is formed. The brake system switching valve 65 is interposed between the proportional valves 62, 67 and the mode switching valve 66.

[0086] Specifically, for example, the brake system switching valve 65 may be a two-position solenoid switching valve having a spool that can be switched between a brake control proportional valve oil passage forming position (lower position in FIG. 2) at which a brake control proportional valve oil passage is formed and a pedal proportional valve oil passage forming position (upper position in FIG. 2) at which a pedal proportional valve oil passage is formed, in response to a command input from the controller 101. In the specific example shown in FIG. 2, when the solenoid of the brake system switching valve 65 is in a non-excited state, the spool of the brake system switching valve 65 is disposed at the pedal proportional valve oil passage forming position, and when the solenoid of the brake system switching valve 65 is in an excited state, the spool of the brake system switching valve 65 is disposed at the brake control proportional valve oil passage forming position. However, the structure of the brake system switching valve 65 is not limited to this specific example. The brake system switching valve 65 may be configured so that the spool is positioned at a pedal proportional valve oil passage forming position when the solenoid is in an excited state, and so that the spool is positioned at a brake control proportional valve oil passage forming position when the solenoid is in a non-excited state.

[0087] The mode changeover valve 66 of the auxiliary valve group is a changeover valve for switching between a state in which a bypass oil passage is formed and a state in which a proportional valve oil passage is formed. The brake system changeover valve 65 of the auxiliary valve group is a changeover valve for switching between a state in which the brake control proportional valve oil passage is formed and a state in which the pedal proportional valve oil passage is formed. The configurations of the brake system changeover valve 65 and the mode changeover valve 66 of the auxiliary valve group are substantially the same as the configurations of the brake system changeover valve 65 and the mode changeover valve 66 of the main winding valve group described above, so detailed explanations thereof will be omitted.

[0088] The emergency brake changeover valve 69 is a changeover valve for switching between a pump connection state in which the oil chamber 44 of the main winding clutch brake 48 is connected to the pilot pump 36, and a tank connection state in which the oil chamber 44 is connected to a tank. Specifically, for example, the emergency brake changeover valve 69 may be a two-position solenoid changeover valve having a spool that can be switched between a supply position (left position in FIG. 2) that allows the hydraulic oil from the pilot pump 36 to be supplied to the oil chamber 44, and a discharge position (right position in FIG. 2) that allows the hydraulic oil in the oil chamber 44 to be discharged from the oil chamber 44 to the tank.

[0089] In normal operation, as shown in FIG. 2, the controller 101 sets the spool of the emergency brake changeover valve 69 to the supply position, and the state of the emergency brake changeover valve 69 is the pump connected state. On the other hand, in an emergency, the controller 101 switches the spool of the emergency brake changeover valve 69 from the supply position to the discharge position. That is, the state of the emergency brake changeover valve 69 switches from the pump connected state to the tank connected state, and the oil chamber 44 is connected to the tank. As a result, a braking force is generated on the main winding drum DR1, that is, the main winding drum DR1 is braked, and the rotation of the main winding drum DR1 is decelerated and stopped. The configuration of the emergency brake changeover valve 69 of the auxiliary winding valve group is substantially the same as the configuration of the emergency brake changeover valve 69 of the main winding valve group described above, and therefore a detailed description thereof will be omitted.

[0090] The drum rotation detector 102 shown in FIG. 3 may include, for example, the main winding rotation sensor 102A and the auxiliary winding rotation sensor 102B shown in FIG. 2. The main winding rotation sensor 102A detects the main winding rotation amount ωm, which is the rotation amount of the main winding drum DR1, and inputs the detection result of the main winding rotation amount ωm to the controller 101. The auxiliary winding rotation sensor 102B detects the auxiliary winding rotation amount ωa, which is the rotation amount of the auxiliary winding drum DR2, and inputs the detection result of the auxiliary winding rotation amount ωa to the controller 101. Note that the main winding rotation sensor 102A may be a sensor that detects the movement of another member (for example, the rotation amount of the main winding point sheave 205) corresponding to the rotation amount of the main winding drum DR1. Similarly, the auxiliary winding rotation sensor 102B may be a sensor that detects the movement of another member (for example, the rotation amount of the auxiliary winding point sheave 206) corresponding to the rotation amount of the auxiliary winding drum DR2.

[0091] The monitor switch 107 is an example of a weight setting input device used to set the hammer grab weight, which is the weight of the hammer grab 10. When the operator wants to set the hammer grab weight, the operator presses the monitor switch 107, and the hammer grab weight is stored in the controller 101. The monitor switch 107 may be provided, for example, on a monitor (not shown) arranged in the cabin of the upper rotating body 202, or may be provided on a portable information terminal outside the upper rotating body 202 that can be operated by the operator.

[0092] Specifically, for example, the operator checks whether the state of the hammer grabbing device 10 satisfies a predetermined condition, and when the predetermined condition is satisfied, inputs the weight setting input device, which inputs a signal related to the input to the controller 101, and upon receiving the input of the signal, the controller 101 may set a value calculated using the load value detected by the load value detector 108 at that time and a relational expression stored in advance as the weight of the hammer grabbing device 10. In this case, the predetermined condition may include, for example, that the hammer grabbing device 10 is not on the ground. Also, the predetermined condition may include, for example, that the hammer grabbing device 10 is not on the ground and that no soil is held within the hammer grabbing device 10.

[0093] The load value detector 108 is a sensor capable of detecting a load value correlated to the hammer grab weight. In this embodiment, the load value detector 108 may include a load cell attached to the lower spreader 210. In this case, the load cell may be configured to be capable of detecting a load acting on the derricking wire rope 211 wound around the lower spreader 210. However, the load value detector 108 is not limited to a load cell attached to the lower spreader 210 as long as it is a sensor disposed at a position capable of detecting a load value correlated to the hammer grab weight. The load value detector 108 inputs the detection result of the load value to the controller 101. The controller 101 can obtain the load value correlated to the hammer grab weight based on the detection result input from the load value detector 108.

[0094] Generally, a crane is equipped with a moment limiter (overload prevention device). This moment limiter calculates the moment acting on the crane using information such as the length of the hoisting member including the boom, the angle (posture) of the hoisting member, and the tension of the rope, and when the calculated moment exceeds an allowable range, it stops the operation of the crane or issues an alarm. This moment limiter calculates the moment using the tension of the wire rope detected by a load value detector such as a load cell. The load value detector 108 of the excavating machine 200 according to this embodiment may also be used as a detector for calculating the moment.

[0095] The excavation control device 100 may be provided with a temporary cancel switch (not shown). The temporary cancel switch is an input device that is input by the operator when the operator wishes to temporarily cancel automatic control by the excavation control device.

[0096] The swing angle detector 104 detects the swing angle of the upper swing body 202 relative to the lower body 201. The hoisting angle detector 105 detects the hoisting angle of the hoisting member 204 relative to the upper swing body 202. The swing angle detector 104 inputs the swing angle detection result to the controller 101, and the hoisting angle detector 105 inputs the hoisting angle detection result to the controller 101. In this embodiment, the hoisting angle is the boom hoisting angle relative to the upper swing body 202.

[0097] The controller 101 (mechatronics controller) controls the operation of the excavating machine 200. The controller 101 includes a computer, and the computer includes an arithmetic processing device such as a CPU or an MPU, and a memory.

[0098] As shown in FIG. 3, the controller 101 includes a condition setting unit 111, a hammer grab state calculation unit 112, a screen display calculation unit 113, and a command current value calculation unit 114.

[0099] The condition setting unit 111 performs various settings necessary for performing excavation work. The condition setting unit 111 performs, for example, initial settings, setting of conditions other than the initial settings, and the like. Specifically, the condition setting unit 111 sets, for example, the weight of the hammer grab. The condition setting unit 111 may calculate the weight of the hammer grab using, for example, the load value detected by the load value detector 108. Specifically, the condition setting unit 111 may be configured to set a value calculated using the load value detected by the load value detector 108 at the time when the monitor switch 107 is pressed by the operator as the weight of the hammer grab, and to store the set hammer grab weight in a memory. Also, the condition setting unit 111 may set an input value (for example, a numerical value) input by the operator to the weight setting input device as the weight of the hammer grab.

[0100] The hammer grab state calculation unit 112 calculates various state quantities related to the operation of the hammer grab 10, such as the height of the hammer grab 10 and the falling speed of the hammer grab 10.

[0101] The hammer grab state calculation unit 112 calculates the number of layers of the main winding wire rope R1 wound around the main winding drum DR1 using the main winding rotation amount ωm detected by the main winding rotation sensor 102A of the drum rotation detector 102. The number of layers means the number of layers of the main winding wire rope R1 wound around the main winding drum DR1. Information such as the size of the main winding drum DR1, including the diameter and axial length of the main winding drum DR1, and the diameter of the main winding wire rope R1, is stored in advance in the controller 101. Therefore, the hammer grab state calculation unit 112 can obtain the number of rotations of the main winding drum DR1 from the reference position using the main winding rotation amount ωm, and can also calculate the number of layers (winding layers) of the main winding wire rope R1 at that time.

[0102] The hammer grab state calculation unit 112 calculates the number of layers of the auxiliary winding wire rope R2 wound around the auxiliary winding drum DR2 using the auxiliary winding rotation amount ωa detected by the auxiliary winding rotation sensor 102B of the drum rotation detector 102. The number of layers means the number of layers of the auxiliary winding wire rope R2 wound around the auxiliary winding drum DR2. Information such as the size of the auxiliary winding drum DR2, including the diameter and axial length of the auxiliary winding drum DR2, and the diameter of the auxiliary winding wire rope R2, is stored in advance in the controller 101. Therefore, the hammer grab state calculation unit 112 can obtain the number of rotations of the auxiliary winding drum DR2 from the reference position using the auxiliary winding rotation amount ωa, and can also calculate the number of layers (winding layers) of the auxiliary winding wire rope R2 at that time.

[0103] The hammer grab state calculation unit 112 calculates the height of the hammer grab 10 at that time point, using the bottom 12 of the hole in the work target (excavation target) at that time point as the origin. The height of the hammer grab 10 is a positive value when the hammer grab 10 is above the bottom 12. The hammer grab state calculation unit 112 periodically and repeatedly calculates the height of the hammer grab 10 during hammer grab work, thereby acquiring the height of the hammer grab 10 during hammer grab work in real time.

[0104] The hammer grab state calculation unit 112 can calculate the height of the hammer grab 10 (hammer grab height) using the detection result of the main winding rotation amount ωm input to the controller 101 from the main winding rotation sensor 102A of the drum rotation detector 102.

[0105] Specifically, for example, the hammer grab state calculation unit 112 can obtain a more accurate hammer grab height taking the number of layers into consideration by calculating the hammer grab height using the detection result of the main hoisting rotation amount ωm input from the main hoisting rotation sensor 102A to the controller 101 and the number of layers (winding layers) of the main hoisting wire rope R1. However, the hammer grab state calculation unit 112 may calculate the hammer grab height using the detection result of the main hoisting rotation amount ωm without taking the number of layers into consideration.

[0106] The hammer grab state calculation unit 112 can obtain the origin, which is the reference for the hammer grab height, i.e., the position of the bottom 12 of the hole, for example, as follows: The hammer grab state calculation unit 112 can determine the ground clearance height, which is the height position when the hammer grab 10 separates from the bottom 12, based on the load value change in which the load value detected by the load value detector 108 increases during the process in which the main hoisting wire rope R1 is wound by the main hoisting drum DR1 from a state in which the hammer grab 10 is in contact with the bottom 12 of the hole. The hammer grab state calculation unit 112 sets this ground clearance height as the origin at that time.

[0107] The hammer grab state calculation unit 112 uses the hammer grab height calculated as above to calculate the amount of decrease in the hammer grab height per unit time, that is, the falling speed of the hammer grab 10.

[0108] A screen display calculation unit 113 obtains the hammer grab height calculated by the hammer grab state calculation unit 112, a control state determined by a command current value calculation unit 114 described later, and the like, and displays on a monitor 115 information useful to the operator.

[0109] The command current value calculation unit 114 calculates a control command based on the state of the hammer grab 10, the detection results input from various sensors, operator settings, etc., and outputs the control command to controlled objects such as proportional valves 61A, 61B, 62, 63A, 63B, 64, 67, 68 and switching valves 65, 66, 69.

[0110] Specifically, for example, the command current value calculation unit 114 may determine the control state of the excavating machine 200 based on the state of the hammer grab 10, the detection results input from various sensors, the operator setting, etc., calculate a control command corresponding to the determined control state, and output the control command to the controlled object. Examples of the control state include a no control state, an impact force adjustment state, a landing brake control state, a loosening control state, a hoisting control state, a water landing speed control state, an underwater speed control state, and an assist function temporarily disabled state.

[0111] The no-control state is a state in which the proportional valve current command value is zero while the switching valve controls the hydraulic circuit by the proportional valve current command value. The impact force adjustment state is a state in which the brake is appropriately applied while the hammer grab 10 is free falling to adjust the falling speed, and / or the hammer grab 10 is temporarily stopped at a certain height to adjust the impact force at the time of landing. The landing brake control state is a state in which brake control is performed to stop the rotation of the winch drum when it is determined that the hammer grab 10 has landed.

[0112] The command current value calculation unit 114 executes impact force adjustment control when the control state is an impact force adjustment state. The command current value calculation unit 114 executes landing brake control when the control state is a landing brake control state. The command current value calculation unit 114 executes water landing speed control when the control state is a water landing speed control state. The command current value calculation unit 114 executes underwater speed control when the control state is an underwater speed control state. The command current value calculation unit 114 executes assist function disable control to temporarily disable the assist function when the control state is an assist function temporarily disabled state.

[0113] Moreover, the controller 101 according to this embodiment performs the above-mentioned landing judgment control. That is, when the water in the casing 11 is taken into consideration in the landing judgment, the controller 101 judges whether or not the hammer grab 10 has landed by using the rotation amount (the height information), and when the water in the casing 11 is not taken into consideration in the landing judgment, the controller 101 judges whether or not the hammer grab 10 has landed by using the load value.

[0114] FIG. 4 is a flowchart showing an example of a calculation control operation in the landing determination control performed by the controller 101 of the excavation control device 100.

[0115] In step S11 of Fig. 4, the controller 101 acquires water information, which is information about the water in the casing 11, from the water information provider 91. Specifically, if the water information provider 91 includes a water information input device capable of receiving input from an operator, the operator inputs water information to the water information input device, taking into consideration the water level in the casing 11 that has been determined in advance in a preliminary survey. The water information may be information about the presence or absence of water, may be the water level (numerical value), or may be information about whether water needs to be taken into consideration. The water information input device outputs the water information inputted to the water information input device to the controller 101, thereby enabling the controller 101 to acquire the water information.

[0116] In step S12, the controller 101 sets the landing determination mode to a water consideration mode that takes into account water in the casing 11 or a non-consideration mode that does not take into account water in the casing 11 based on the acquired water information. Specifically, for example, when the operator inputs water information indicating that there is no water in the casing 11, the controller 101 may set the landing determination mode to the non-consideration mode, and when the operator inputs water information indicating that there is water in the casing 11, the controller 101 may set the landing determination mode to the water consideration mode. Also, when the operator inputs the water level in the casing 11 to the water information input device as water information, or when the water level sensor inputs water information related to the water level in the casing 11 to the controller 101, the controller 101 may set the landing determination mode based on a comparison result between the water level and a predetermined water level threshold value. That is, the controller 101 may set the landing determination mode to a non-consideration mode when the water level is below the water level threshold, and may set the landing determination mode to a water consideration mode when the water level is equal to or greater than the water level threshold.

[0117] In step S13, the controller 101 determines whether the landing determination mode is the water consideration mode. If the landing determination mode is the water consideration mode (YES in step S13), the controller 101 performs the processes in steps S14 and after, and if the landing determination mode is the non-consideration mode (NO in step S13), the controller 101 performs the processes in steps S16 and after.

[0118] [Water Consideration Mode] When the landing judgment mode is the water consideration mode, the controller 101 acquires landing judgment indicators for the water consideration mode (step S14), and judges whether or not the landing judgment conditions for the water consideration mode are satisfied using the acquired landing judgment indicators (step S15). The landing judgment indicators for the water consideration mode need only include at least the hammergrab height, but in this embodiment, they include both the hammergrab height and the load value. When the landing judgment mode is the water consideration mode, the controller 101 uses the hammergrab height, i.e., the height information, as the main indicator for landing judgment, so that it is possible to appropriately judge the landing of the hammergrab 10. Also, in this embodiment, when the landing judgment mode is the water consideration mode, the controller 101 uses the height information as the main indicator for landing judgment and uses the load value as an auxiliary indicator for landing judgment, so that it is possible to more appropriately judge the landing of the hammergrab 10.

[0119] The landing determination condition in the water consideration mode may be, for example, the condition expressed by the following formula (1).

[0120]

number

[0121] Here, H hammer is the hammer grab height, and H OpenClose is the length of wire rope required to open and close the hammer grab 10, and W sensing is the load value (current load value) acquired in step S14, and W hammer is the weight of the hammergrab 10. α is a correction constant for taking buoyancy into account, and β1 is a positive number less than 1 that is set to appropriately determine the landing of the hammergrab 10 in the water consideration mode.

[0122] Wire rope length required for opening and closing the hammer grab 10 (H OpenClose ) is the length of wire rope that needs to be unwound from the main winding drum DR1 in order for the grab 10B of the hammer grab 10 to switch from a closed state to an open state. This wire rope length (HOpenClose When the wire rope length (H ) differs depending on the type of hammer grab 10, the operator must input the wire rope length (H OpenClose ) information is input to the controller 101 to control the wire rope length (H OpenClose In addition, when the type of the hammer grab 10 can be automatically detected, the controller 101 may set the wire rope length (H OpenClose ) may be set.

[0123] When the landing judgment condition in the water consideration mode is the condition shown in formula (1), the height threshold for landing judgment (first height threshold) is "-H OpenClose That is, the first height threshold is the wire rope length (H OpenClose ) with a negative sign. The load threshold for landing judgment (first load threshold) is "αβ1W hammer That is, the first load threshold is the weight (W hammer ) multiplied by the constants α and β1.

[0124] In step S15, the controller 101 controls the hammer grab height (H hammer ) is smaller than a first height threshold, and the current load value (W sensing) is smaller than a first load threshold is satisfied. If the first height condition is satisfied and the first load condition is satisfied (YES in step S15), the controller 101 determines that the hammergrab 10 has landed, and performs the process of step S18 (brake control described below). On the other hand, if at least one of the first height condition and the first load condition is not satisfied (NO in step S15), the controller 101 does not perform the process of step S18 (brake control). If at least one of the first height condition and the first load condition is not satisfied (NO in step S15), the controller 101 calls and executes the process of the flowchart shown in FIG. 4 (for example, the process after step S13) for each control period.

[0125] [Non-considerate mode] When the landing judgment mode is the non-consideration mode, the controller 101 acquires a landing judgment index for the non-consideration mode (step S16), and judges whether or not the landing judgment condition for the non-consideration mode is satisfied using the acquired landing judgment index (step S17). The landing judgment index for the non-consideration mode may include at least the load value, but in this embodiment, it includes both the load value and the hammer grab height (height information). When the landing judgment mode is the non-consideration mode, the controller 101 uses the load value as the main index for landing judgment and the hammer grab height as a supplementary index for landing judgment, so that the landing of the hammer grab 10 can be judged more appropriately.

[0126] The landing determination condition in the non-consideration mode may be, for example, the condition shown in the following formula (2).

[0127]

number

[0128] Here, H hammer is the hammer grab height, and H OpenClose is the length of wire rope required to open and close the hammer grab 10, and W sensingis the load value (current load value) acquired in step S16, and W hammer is the weight of the hammer grub 10. const is a constant equal to or greater than 0, and β2 is a positive constant less than 1 that is set to appropriately determine the landing of the hammergrab 10 in the non-consideration mode. const may be a constant greater than 0.

[0129] When the landing judgment condition in the non-consideration mode is the condition shown in formula (2), the height threshold for landing judgment (second height threshold) is "-H OpenClose +H const That is, the second height threshold is the wire rope length (H OpenClose ) with a negative sign and add the constant "H const " The load threshold for landing judgment (second load threshold) is "β2W hammer That is, the second load threshold is the weight (W hammer ) multiplied by a constant β2. Note that the constant β2 may be a value different from the constant β1 or may be the same value as the constant β1.

[0130] In step S17, the controller 101 controls the hammer grab height (H hammer ) is smaller than a second height threshold, and the current load value (W sensing) is smaller than a second load threshold is satisfied. If the second height condition is satisfied and the second load condition is satisfied (YES in step S17), the controller 101 determines that the hammergrab 10 has landed, and performs the process of step S18 (brake control described below). On the other hand, if at least one of the second height condition and the second load condition is not satisfied (NO in step S17), the controller 101 does not perform the process of step S18 (brake control). If at least one of the second height condition and the second load condition is not satisfied (NO in step S17), the controller 101 calls and executes the process of the flowchart shown in FIG. 4 (for example, the process after step S13) for each control period.

[0131] When the landing determination condition is satisfied (YES in step S15 or YES in step S17), the controller 101 performs brake control (step S18). That is, when the controller 101 determines that the hammer grab 10 has landed, it performs brake control to stop the rotation of the main hoisting drum DR1. In this embodiment, the controller 101 not only determines whether the hammer grab 10 has landed, but also performs brake control to stop the rotation of the main hoisting drum DR1, so that it is possible to further reduce the burden on the operator while suppressing the occurrence of over-reeling, which is a state in which the wire rope is excessively reeled out from the main hoisting drum DR1 after the hammer grab 10 has landed.

[0132] Specifically, the controller 101 outputs a command to the mode switching valve 66 to position the spool of the mode switching valve 66 at the proportional valve oil passage forming position (left position in FIG. 2), and outputs a command to the brake system switching valve 65 to position the spool of the brake control proportional valve oil passage forming position (lower position in FIG. 2). Then, the controller 101 inputs a main hoisting brake command (command current value) to the main hoisting brake control proportional valve 62 such that full braking is applied to the rotation of the main hoisting drum DR1. As a result, a large braking force is generated in the main hoisting clutch brake 48 immediately after the hammer grab 10 lands on the bottom 12, and excessive unwinding of the main hoisting wire rope R1 from the main hoisting drum DR1 is suppressed.

[0133] Next, the landing determination in the water consideration mode and the landing determination in the water non-consideration mode will be described in more detail with reference to FIGS.

[0134] 5 is a diagram showing an example of changes over time in the hammer grab height and the load value during excavation work when there is no need to take water into consideration inside the casing 11, i.e., when the landing determination mode is set to the non-consideration mode. In the specific example shown in (a) to (e) of FIG. 5, no water has accumulated inside the casing 11.

[0135] In FIG. 5, at time t0, the hammer grab 10 is in contact with the bottom of the casing 11, and the load value detected by the load value detector 108 is zero or a value close to zero. When the main hoisting wire rope R1 is wound up by being wound around the main hoisting drum DR1 from time t0, the controller 101 determines the ground clearance height based on the load value change that increases the load value. In this embodiment, the controller 101 sets the ground clearance height determined based on the load value change as the origin (zero point). In this embodiment, the controller 101 updates the origin based on the load value change before the next excavation operation. In the graph at the top of FIG. 5, the origin of the hammer grab height is the height position corresponding to the intersection of the vertical and horizontal axes of the graph.

[0136] Specifically, in the excavation work, the hammer grab 10 falls in the casing 11 with the grab 10B open (open state), so that when the excavation work is completed and the hammer grab 10 is grounded on the bottom 12 (for example, at time t0 in FIG. 5), the grab 10B is in the open state (open state) as shown in FIG. 5(a). At this time t0, the main hoisting wire rope R1 that suspends the hammer grab 10 has some slack. When the main hoisting wire rope R1 starts to be wound up from this time t0, the amount of slack in the main hoisting wire rope R1 gradually decreases. When the main hoisting wire rope R1 is further wound up with no slack in the main hoisting wire rope R1, the grab 10B closes while the hammer grab 10 is kept grounded as shown in FIG. 5(b). As a result, the soil is held in the grab 10B. Then, when the main hoisting wire rope R1 is further wound up, the hammer grab 10 comes off the ground as shown in Fig. 5(c), and the load value increases or increases rapidly at time t1. In this embodiment, the controller 101 determines that the hammer grab 10 has come off the ground at this point in time t1.

[0137] The controller 101 sequentially calculates the hammer grab height using the amount of rotation detected by the drum rotation detector 102, with the ground clearance height (origin) as a reference. When the hammer grab 10 is disposed above the ground clearance height (origin), the hammer grab height is a positive value greater than zero. In this embodiment, the controller 101 calculates the hammer grab height using the amount of rotation of the main hoisting drum DR1 detected by the drum rotation detector 102, so the hammer grab height can be a negative value. If the hammer grab height is a negative value when the hammer grab 10 is in contact with the bottom 12, this means that the wire rope is slackened by an amount equivalent to the absolute value of the negative value.

[0138] After the hammer grabbing 10 leaves the ground at time t1, the main hoisting wire rope R1 is further wound up, and at time t2, the hammer grabbing 10 is removed from the casing 11. If the hammer grabbing 10 holds soil, soil disposal is performed before the next excavation operation. This soil disposal operation is an operation for discharging the soil held by the hammer grabbing 10 from the hammer grabbing 10 to a predetermined place outside the casing 11. In this soil disposal operation, a rotating operation of the upper rotating body 202 is performed, so the rotation angle in the soil disposal operation (the rotation angle of the upper rotating body 202 relative to the lower body 201) is different from the rotation angle in the excavation operation. In addition, during soil removal operations, the upper rotating body 202 may rotate and the hoisting member 204 may be raised and lowered. In this case, the rotation angle and the hoisting angle during soil removal operations (the hoisting angle of the hoisting member 204 relative to the upper rotating body 202) are different from the rotation angle and the hoisting angle during excavation operations.

[0139] When the soil removal operation is completed, the hoisting angle of the hoisting member 204 and the rotation angle of the upper rotating body 202 are adjusted so that the hammer grab 10 is again positioned in a position corresponding to the casing 11 for the next excavation operation. At the start of the next excavation operation, it is preferable that at least a part of the hammer grab 10 is positioned inside the casing 11. In the specific example of Fig. 5, the next excavation operation is started at time t3.

[0140] In this drilling operation, the hammer grab 10 starts falling (e.g., free falling) at time t3, approaches the bottom 12 while falling within the casing 11 as shown in (d) of Figure 5, and lands on the bottom 12 at time t5 as shown in (e) of Figure 5.

[0141] When the landing judgment mode is set to the non-consideration mode, the hammer grab 10 falling inside the casing 11 during drilling operation does not or hardly encounters water resistance until it lands on the bottom 12, so the falling speed of the hammer grab 10 immediately before it lands on the bottom 12 becomes relatively large. In this case, as shown by the load value change in the time period from time t5 to time t6 in the lower graph of Fig. 5, the change in the load value immediately before and immediately after the hammer grab 10 lands becomes large, so the load value detected by the load value detector 108 is useful as a main index for judging the landing of the hammer grab 10, and therefore the controller 101 can appropriately judge whether the hammer grab 10 has landed or not by using the load value.

[0142] When the controller 101 determines that the hammer grabbing device 10 has landed, it performs brake control to stop the rotation of the main hoisting drum DR1, specifically, brake control to apply full brake to the main hoisting drum DR1 to stop the rotation of the main hoisting drum DR1. As a result, the rotation of the main hoisting drum DR1 stops at time t6, and the excavation work is completed. This limits the time during which the main hoisting wire rope R1 is paid out from the main hoisting drum DR1 after the hammer grabbing device 10 has landed to a short period from time t5 to time t6, thereby preventing over-payout, which is a state in which the main hoisting wire rope R1 is excessively paid out from the main hoisting drum DR1 after the hammer grabbing device 10 has landed. Moreover, the operator does not need to perform a brake operation after the hammer grabbing device 10 has landed, so the burden on the operator is reduced.

[0143] During the time period from time t3 when the hammer grab 10 starts to fall to time t5 when the hammer grab 10 lands in an excavation operation, in the time period immediately after the start of the fall, the load value detected by the load value detector 108 may temporarily decrease, as shown in the lower graph of Fig. 5. In the specific example of Fig. 5, the load value detected by the load value detector 108 is a value corresponding to the weight of the hammer grab 10 until the start of the fall, but after temporarily decreasing immediately after the start of the fall, it increases again to a value corresponding to or close to the weight of the hammer grab 10 before the hammer grab 10 lands, and then decreases to zero or close to zero as the hammer grab 10 lands on the bottom 12 at time t5.

[0144] Therefore, in this embodiment, when the controller 101 does not take into account the water in the casing 11 in the landing judgment, the controller 101 uses the load value as the main indicator for the landing judgment and uses the height information as an auxiliary indicator for the landing judgment to judge whether the hammer grab 10 has landed or not.

[0145] As shown in the upper graph of Fig. 5, the time period immediately after the start of the fall is a time period in which the hammer grab 10 is in a relatively high position, in other words, the vertical distance between the hammer grab height and the height off the ground (origin) is large. Therefore, even if a temporary decrease in the load value occurs in the time period immediately after the start of the fall, the controller 101 can use the height information to distinguish between the temporary decrease in the load value and a decrease in the load value caused by the hammer grab 10 landing. In other words, the height information as an auxiliary index is intended to exclude the temporary decrease in the load value from the criteria for determining whether the hammer grab has landed.

[0146] In this embodiment, the second height threshold is "-H OpenClose +H const " for the following reasons:

[0147] The ground clearance height (origin) is updated when the grab 10B of the hammergrab 10 is closed as shown in Fig. 5(b) and (c), whereas the grab 10B of the hammergrab 10 is in an open state when the hammergrab 10 is falling during excavation work (Fig. 5(d)) and when the hammergrab 10 lands on the ground (Fig. 5(e)). In the hammergrab 10 according to this embodiment, in order for the grab 10B to switch from a closed state to an open state, the main hoisting wire rope R1 needs to be unwound by a predetermined length from the main hoisting drum DR1. This predetermined length is the wire rope length (H OpenClose ) The hammer grab height, which is the variable on the vertical axis of the graph at the top of FIG. 5, is a converted value calculated using the amount of rotation of the main hoist drum DR1 detected by the drum rotation detector 102. Therefore, the amount of rotation of the main hoist drum DR1 when the hammer grab 10 actually lands during excavation work, i.e., when the hammer grab 10 reaches the height off the ground (origin) during excavation work, is longer than the amount of rotation of the main hoist drum DR1 when the hammer grab 10 was positioned at the time the origin was updated before the excavation work, and is therefore longer than the wire rope length (H OpenClose 5, the hammer grab height (converted value) calculated using the rotation amount when the grab 10B is in the open state is larger by the wire rope length (H OpenClose ) is smaller than the wire rope length (H OpenClose The hammer grab 10 lands at a time t5 at which the converted value corresponds to a height position obtained by subtracting

[0148] As described above, when the landing judgment mode is the non-consideration mode, the height information is not intended to judge whether the hammergrab 10 actually lands, but is intended to exclude a temporary decrease in the load value immediately after the start of the fall from the landing judgment criteria. Therefore, when the landing judgment mode is the non-consideration mode, the second height threshold is "-HOpenClose ", but above that "-H OpenClose +H const ". In other words, the second height threshold is set to 100% of the first height threshold (-H OpenClose ) In other words, the height position corresponding to the second height threshold is set higher than the height position corresponding to the first height threshold, and is not a position corresponding to the bottom 12, but a position higher than the bottom 12.

[0149] In the specific example shown in FIG. 5, the hammer grab height "H hammer ” at time t4 is the second height threshold “-H OpenClose +H const ", but the primary decrease in the load value immediately after the start of the fall occurs in the time period before time t4, i.e., in the time period when the hammer grab height is equal to or greater than the second height threshold, and thereafter, the load value increases again to a value corresponding to or close to the value corresponding to the weight of the hammer grab 10 before the hammer grab height falls below the second height threshold. Therefore, the controller 101 determines whether or not the condition that the hammer grab height is smaller than the second height threshold (second height condition) is satisfied, and calculates the current load value (W sensing By determining whether the condition (second load condition) that the first load threshold value is smaller than the second load threshold value is satisfied, it is possible to appropriately determine whether the hammer grab 10 has landed while excluding the temporary decrease in the load value immediately after the start of the fall from the criteria for determining the landing.

[0150] 6 is a diagram showing an example of changes over time in the hammer grab height and the load value during excavation work when it is necessary to take into account water in the casing 11, i.e., when the landing determination mode is set to the water consideration mode. In the specific example shown in (a) to (e) of FIG. 6, a relatively large amount of water has accumulated in the casing 11.

[0151] The procedure for updating the ground clearance height (origin) performed before the next excavation operation in the water consideration mode shown in Fig. 6 is the same as the procedure for updating in the non-water consideration mode described with reference to Fig. 5. Specifically, when the main hoisting wire rope R1 is wound up by being wound around the main hoisting drum DR1 from time t0 in Fig. 6, the load value increases or increases rapidly at time t11. The controller 101 determines that the hammer grab 10 has left the ground at time t11. The controller 101 sets the ground clearance height determined based on the change in the load value as the origin (zero point). In the upper graph of Fig. 6, the origin of the hammer grab height is the height position corresponding to the intersection of the vertical axis and the horizontal axis of the graph.

[0152] After the hammer grabbing 10 leaves the ground at time t11, the main hoisting wire rope R1 is further wound up, and at time t12, the hammer grabbing 10 is taken out of the casing 11. If the hammer grabbing 10 holds earth and sand, an earth removal operation is performed before the next excavation operation. The reason why the load value detected by the load value detector 108 is larger than the load value corresponding to the weight of the hammer grabbing 10 in the first half of the time period from time t11 to time t12 is that the hammer grabbing 10 receives resistance from the water when it rises in the water. Therefore, when the hammer grabbing 10 goes out of the water into the air in the second half of the time period from time t11 to time t12, the load value detected by the load value detector 108 decreases to the load value corresponding to the weight of the hammer grabbing 10. In the specific example of FIG. 6, the next excavation operation is started at time t13.

[0153] In this drilling operation, the hammer grab 10 starts falling (e.g., free fall) at time t13, lands on the water at time t14, and from time t14 onwards, approaches the bottom 12 while falling through the water within the casing 11 as shown in (d) of Figure 6, and lands on the bottom 12 at time t15 as shown in (e) of Figure 6.

[0154] When the controller 101 determines that the hammer grabbing device 10 has landed, it performs brake control to stop the rotation of the main hoisting drum DR1, specifically, for example, brake control to apply full brake to the main hoisting drum DR1 to stop the rotation of the main hoisting drum DR1, and as a result, the rotation of the main hoisting drum DR1 stops at time t16, and the excavation work is completed. This limits the time during which the main hoisting wire rope R1 is paid out from the main hoisting drum DR1 after the hammer grabbing device 10 has landed to a short period from time t15 to time t16, thereby preventing over-payout, which is a state in which the main hoisting wire rope R1 is excessively paid out from the main hoisting drum DR1 after the hammer grabbing device 10 has landed. Moreover, the operator does not need to perform a brake operation after the hammer grabbing device 10 has landed, so the burden on the operator is reduced.

[0155] When the landing judgment mode is set to the water consideration mode, the hammer grab 10 falling inside the casing 11 during drilling work lands on water before landing on the bottom 12, descends through the water, and continues to encounter resistance from the water until it lands on the bottom 12, so that the falling speed of the hammer grab 10 just before it lands on the bottom 12 is smaller than when there is no water in the casing 11 or the water level is relatively low. Also, because the hammer grab 10 encounters resistance from the water when it falls through the water, the load value detected by the load value detector 108 is smaller than when there is no water in the casing 11 or the water level is relatively low. In this case, as shown by the change in the load value from time t14 to time t16 in the lower graph of FIG. 6, the amount of change in the load value immediately before and immediately after the hammer grab 10 lands also becomes small, so it is not preferable to use the load value detected by the load value detector 108 as the main index for determining whether the hammer grab 10 has landed.

[0156] On the other hand, the members constituting the main parts of the hammergrab 10 are usually formed using materials such as metals whose specific gravity (specific gravity based on water) is considerably greater than 1, so even if the hammergrab 10 encounters water resistance while descending in the water, the height of the hammergrab will steadily decrease until the hammergrab 10 lands, as shown in the upper graph of Fig. 6. Therefore, when water has accumulated in the casing 11 and the water level is relatively high, height information correlating with the hammergrab height is useful as a main index for determining whether the hammergrab 10 has landed, and therefore the controller 101 can appropriately determine whether the hammergrab 10 has landed using the height information.

[0157] In this embodiment, the first height threshold is "-H OpenClose The first height threshold (-H OpenClose ) is the second height threshold (-H OpenClose +H const ) The height position corresponding to the first height threshold is set lower than the height position corresponding to the second height threshold, and is a position corresponding to the bottom 12. This is because when the landing determination mode is set to the water consideration mode, the hammer grab height, i.e., height information, is used as the main index for landing determination.

[0158] Similarly, when the landing judgment mode is set to the water consideration mode, the hammer grab height (converted value) calculated using the rotation amount when the grab 10B of the hammer grab 10 is in the open state is calculated by multiplying the actual height position of the hammer grab 10 by the wire rope length (H OpenClose ) is smaller than the value. Therefore, the controller 101 calculates the distance from the ground height (origin) to the wire rope length (H OpenClose At time t15 when the converted value becomes a height position obtained by subtracting (or less than) the height position of the hammer grab 10, it is determined that the hammer grab 10 has landed.

[0159] The operator setting 109 and the previous setting stored value 110 in FIG. 3 are outlined below.

[0160] The operator setting 109 (operator setting device) may be configured to perform various settings and input the set information to the controller 101. The various settings include, for example, setting whether the hammer grab 10 is connected to the main hoisting wire rope or the auxiliary hoisting wire rope, setting the position of the casing 11 (setting the height of the top position of the casing 11, the swivel angle, the hoisting angle, etc.), setting the hammer grab weight, the wire rope length (H OpenClose The controller 101 may include some or all of the following settings: setting of the presence or absence of water, setting of the water surface height, impact force adjustment function setting (setting of the function to activate the brakes while the hammer grab is descending), ON / OFF setting of each function (for example, setting to turn ON / OFF assist control such as braking control at landing), and buzzer lever vibration setting (setting to warn the operator by sound or lever vibration). The controller 101 may perform various controls based on information input from the operator setting device.

[0161] The previous setting storage value 110 (previous setting storage device) may be a storage device for storing the above-mentioned various settings even when the key of the work machine is turned off. The controller 101 may write the various settings to the previous setting storage device (e.g., a non-volatile memory) when the key is turned off, and may read the various settings from the previous setting storage device the next time the key is turned on to perform various controls.

[0162] [Variation 1] Next, an excavation control device 100 according to a first modified example of this embodiment will be described. In this first modified example, the controller 101 judges whether or not the swivel angle and the hoisting angle are within an allowable operation range permitted in excavation work. Since the hammergrab 10 is supported by the hoisting member 204 via a wire rope (main hoisting wire rope R1), the swivel angle and the hoisting angle correlate with the position of the hammergrab 10. Therefore, in this first modified example, the controller 101 can indirectly judge whether or not the hammergrab 10 is located at a position suitable for excavation work, that is, at a position corresponding to the casing 11, by using the swivel angle and the hoisting angle.

[0163] Specifically, the excavation control device 100 may further include a reference input device 92 (see FIG. 2) that receives an input from an operator. When the reference input device 92 receives an input from the operator (e.g., a switch operation), it inputs a signal corresponding to the input to the controller 101. When the controller 101 receives a signal from the reference input device 92, it stores the swing angle at that time as a reference swing angle and stores the hoisting angle at that time as a reference hoisting angle. Specifically, for example, the operator performs an input to the reference input device 92 when the hammer grabbing device 10 is disposed in a position suitable for excavation work. The position of the hammer grabbing device 10 suitable for excavation work may be, for example, a position where at least a part of the hammer grabbing device 10 is disposed inside the casing 11.

[0164] Fig. 7 is a flowchart showing an example of a calculation control operation performed by the controller 101 of the excavation control device 100 according to the first modification. The flowchart shown in Fig. 7 differs from the flowchart shown in Fig. 4 in that it further includes the processes of steps S21 to S24. The processes of steps S11 to S18 in the flowchart shown in Fig. 7 are the same as the processes of steps S11 to S18 in the flowchart shown in Fig. 4. Therefore, the processes of steps S21 to S24 will be mainly described below.

[0165] In this modified example 1, in step S21, the controller 101 determines whether the turning angle and the hoisting angle are within the permissible range for operation. Specifically, the controller 101 determines whether the actual turning angle (θ senkai ) and the reference turning angle (θ casing ) is a predetermined turning angle threshold value (ε θ ) or not. In addition, the controller 101 determines whether the actual elevation angle (γ boom ) and the reference undulation angle (γ casing ) is a predetermined undulation angle threshold value (ε γ) or not. This allows the controller 101 to indirectly determine the relative position of the hammer grab 10 with respect to the casing 11 using the swing angle and the elevation angle.

[0166]

number

[0167]

number

[0168] If both the turning angle difference is less than the turning angle threshold and the descent angle difference is less than the descent angle threshold (YES in step S21), the controller 101 sets the assist function possible flag to "ON" (step S22). On the other hand, if at least one of the turning angle difference is less than the turning angle threshold and the descent angle difference is less than the descent angle threshold is not satisfied (NO in step S21), the controller 101 sets the assist function possible flag to "OFF" (step S23).

[0169] In step S24, the controller 101 determines whether the assist function enable flag is ON. If the assist function enable flag is set to ON (YES in step S24), the controller 101 executes the processes in steps S13 and after. That is, if the slewing angle and the hoisting angle are within the permissible work ranges, the controller 101 permits the processes in steps S13-S18 (automatic control of at least a part of the excavation work) and executes these processes.

[0170] On the other hand, if the assist function enable flag is set to OFF (NO in step S24), the controller 101 does not execute the processes in steps S13 and after. In other words, if the turning angle and the hoisting angle are not within the permissible work range, the controller 101 performs control (assist function disable control) to suspend execution of the processes in steps S13-S18 (the automatic control).

[0171] [Variation 2] Next, a description will be given of the excavation control device 100 according to Modification 2 of the present embodiment. In Modification 2, the controller 101 calculates an initial value of the hammer grab height and acquires the characteristics (delay characteristics) related to the delay of the load value detector 108.

[0172] The controller 101 determines the timing of the hammer grab 10 landing and the timing of the hammer grab 10 leaving the bottom 12 using the load value acquired by the load value detector 108, and acquires the initial value of the height of the hammer grab 10 and the delay-related characteristics of the load value detector 108 using the relative position of the height position of the hammer grab 10 to the reference height position at the landing timing, the relative position of the height position of the hammer grab 10 to the reference height position at the leaving timing, and the changing speed of the height of the hammer grab 10 (the moving speed of the hammer grab 10). Specifically, it is as follows.

[0173] FIG. 8 is a schematic diagram for explaining a method for acquiring the initial value of the hammer grab height and the delay characteristic of the load value detector 108. In this method, the landing of the hammer grab 10 and the lifting off of the hammer grab 10 are repeated, the timing of the landing and the timing of the lifting off of the hammer grab are read by the load value detector 108, the controller 101 calculates the lift value at each timing, and estimates the initial value of the hammer grab height and the delay characteristic of the load value detector 108 using the calculated lift values. The landing and lifting off of the hammer grab 10 may be performed automatically by the controller 101 or may be performed manually by the operator operating a lever. The lift value is a value representing the relative position of the height position of the hammer grab 10 with respect to a predetermined reference height position (for example, the difference between the reference height position and the height position of the hammer grab 10). The reference height position is a reference that is determined in advance before the method is executed, and may be, for example, the height position of the ground (ground level) or another height position. Specifically, the reference height position may be the position of a specific part when the hoisting angle of the hoisting member (the hoisting angle of the boom) is a specific angle and the rotation angle of the upper rotating body is a specific angle. The specific part may be, for example, the tip of the hoisting member (the tip of the boom) or another part of the hoisting member.

[0174] In this method, under the assumption that landing and ground release occur at the same height and that the delay of the load value detector 108 is small compared to the change in speed of the hammer grab 10 and has small variation, the controller 101 calculates the initial value of the hammer grab height and the delay characteristic of the load value detector 108 using, as an example, the least squares method.

[0175] Here, "x*" included in the formula described later is the lift value at the true timing of landing or the lift value at the true timing of taking off from the ground, "x" is the lift value at the time when the controller 101 recognizes the landing or taking off from the ground of the hammer grab 10, "v" is the speed of the hammer grab 10 at the time when the controller 101 recognizes the landing or taking off from the ground, and "Δt" is the delay of the load value detector 108. The unit of the delay Δt of the load value detector 108 is time. Due to the delay of the load value detector 108, the timing when the controller 101 recognizes the landing or taking off from the ground (the timing shown by the solid line in FIG. 8) is shifted later than the true timing of landing or taking off from the ground shown by the dashed line in FIG. 8.

[0176] Based on the above, the following equation (5) holds: Here, the upward direction is the positive direction in the coordinate system, but the same equation holds even if the downward direction is the positive direction in the coordinate system.

[0177]

number

[0178] In addition, there are two patterns, landing and taking off the ground, and if the number of repetitions is N, then the following formula (6) holds. Note that among the subscripts attached to "x" and "v", "i=1" indicates taking off the ground, "i=2" indicates landing, and "j" indicates that the number of repetitions is the jth ("i=1,2" and "J=1,2,...,N").

[0179]

number

[0180] Therefore, the sum of squares of the error Se when “x*” and “Δt” are defined is expressed by the following equation (7).

[0181]

number

[0182] The least squares solution can be found from the following equation (8).

[0183]

number

[0184] "x*" is expressed by the following equation (9), and "Δt" is expressed by the following equation (10).

[0185]

number

[0186]

number

[0187] In addition, “D” in equations (9) and (10) is a value expressed by the following equation (11).

[0188]

number

[0189] In this modified example 2, the controller 101 can acquire the initial value of the height of the hammer grab 10 and the characteristics related to the delay of the load value detector 108. Also, the controller 101 can more accurately calculate the height of the hammer grab 10 by taking into account the characteristics related to the delay of the load value detector 108. Note that in this modified example 2, the initial value of the hammer grab height is used as the origin in the first excavation operation. Also, the delay of the load value detector 108 acquired in this modified example 2 is used to correct the detection timing by the amount of the delay in the subsequent excavation operations.

[0190] [Variation 3] In the above-mentioned modified example 2, the controller 101 uses the above-mentioned formulas (5) to (11) to calculate the initial value "x*" of the hammer grab height (i.e., the lifting height value at the true timing of landing and / or the lifting height value at the true timing of leaving the ground) and obtains the characteristic "Δt" related to the delay of the load value detector 108, but as in modified example 3 described below, the controller 101 can also obtain the error (ΔH) due to the wire rope length and the delay (Δt) of the load value detector 108 using a method similar to that of modified example 2. Specifically, it is as follows.

[0191] In this third modification, the controller 101 determines the timing of the hammer grab 10 landing and the timing of the hammer grab 10 leaving the bottom 12, respectively, using the load value acquired by the load value detector 108, and acquires an error ΔH caused by the wire rope length and a delay Δt of the load value detector 108, using the relative position of the height position of the hammer grab 10 to the reference height position at the landing timing, the relative position of the height position of the hammer grab 10 to the reference height position at the ground leaving timing, and the rate of change in the height of the hammer grab 10. The error ΔH is calculated by, for example, calculating the wire rope length (H OpenClose ) may be an error caused by the

[0192] When the error ΔH due to the wire rope length and the delay Δt of the load value detector 108 are taken into consideration, the error Δx between the actual timing of landing or leaving the ground and the timing at which the controller 101 recognizes that the hammer grab 10 has landed or left the ground can be expressed by the following equation (12) using ΔH and Δt.

[0193] Δx=ΔH+vΔt (12) Here, "v" is the speed of the hammergrab 10 at the time when the controller 101 recognizes the landing or leaving the ground.

[0194] This equation (12) can be rewritten as the following equation (13). ΔH=Δx-vΔt (13)

[0195] Equation (13) has the same form as equations (5) and (6) described in Modification 2. Therefore, the controller 101 can obtain the error (ΔH) caused by the wire rope length and the delay (Δt) of the load value detector 108 by using the least squares method given as an example in Modification 2 (specifically, by using equations (7) to (11)). That is, in this Modification 3, in equations (7) to (11) in Modification 2, "x*" is replaced with "ΔH" and "x" is replaced with "Δx", and the same calculation as in Modification 2 is performed.

[0196] In this variant example 3, the controller 101 may obtain the error (ΔH) due to the wire rope length and the delay (Δt) of the load value detector 108 by calculating the above equations (5) to (11) during each excavation operation, and may correct the detection error by the load value detector 108 using the obtained error (ΔH) and the delay (Δt) of the load value detector 108.

[0197] In the above-mentioned variants 2 and 3, a calculation method using the least squares method has been described as an example, but an adaptive signal processing algorithm may be used instead of or together with the least squares method.

[0198] [Variation 4] Next, an excavation control device 100 according to a fourth modified example of this embodiment will be described. In this fourth modified example, when the water in the casing 11 is taken into consideration in the landing judgment, the controller 101 performs control (underwater speed control) to adjust the brake force on the main hoisting drum DR1 so that the occurrence of slack in the main hoisting wire rope R1 is suppressed when the hammer grabs 10 fall through the water. Specifically, for example, the controller 101 may perform control to adjust the brake force on the main hoisting drum DR1 so that the slack state of the wire rope during the fall of the hammer grabs 10 falls within a predetermined slack allowable range. The controller 101 may determine the slack state of the main hoisting wire rope R1 during the fall of the hammer grabs 10 using a load value input from the load value detector 108. In this case, the controller 101 may determine the slack state of the main hoisting wire rope R1 during the fall of the hammer grabs 10 using a relationship between the load value and the slack state obtained by performing a simulation, an experiment, or the like.

[0199] In the case where the water in the casing 11 needs to be taken into consideration in the landing judgment, for example, when water is accumulated in the casing 11 and the water level is relatively high, the hammer grab 10 falling inside the casing 11 during the excavation work will land on the water before landing on the bottom 12, descend through the water, and encounter resistance from the water until it lands on the bottom 12. Therefore, if the falling speed of the hammer grab 10 becomes slower than the payout speed of the main hoisting wire rope R1 paid out from the main hoisting drum DR1, the wire rope may become slack during the fall of the hammer grab 10. On the other hand, when the controller 101 adjusts the braking force on the main hoisting drum DR1 so that the slack state of the wire rope falls within a predetermined slack allowable range, the controller 101 can use the rotation amount to more accurately calculate the height of the hammer grab 10, thereby more appropriately judging whether the hammer grab 10 has landed or not.

[0200] In this fourth modification, when the control state is the underwater speed control state, the controller 101 inputs a main hoisting brake command to the main hoisting brake control proportional valve 62 so that the slack state of the wire rope falls within a predetermined slack tolerance range. This allows the balance between the payout speed of the main hoisting wire rope R1 paid out from the main hoisting drum DR1 and the falling speed of the hammer grab 10 to be appropriately adjusted.

[0201] [Variation 5] Next, an excavation control device 100 according to a fifth modified example of this embodiment will be described. In this fifth modified example, when the water in the casing 11 is not taken into consideration in the landing judgment, the controller 101 performs control (impact force adjustment control) to adjust the braking force on the main hoist drum DR1 so that the falling speed of the hammer grab 10 falls within a predetermined speed allowable range. In this fifth modified example, even if the falling distance of the hammer grab 10 is long and the falling speed is likely to be high during excavation work, for example, the falling speed of the hammer grab 10 can be prevented from becoming excessively high, so that damage to the hammer grab 10 caused by the impact when the hammer grab 10 lands can be prevented.

[0202] In this modification 5, when the control state is the impact force adjustment state, the controller 101 inputs a main hoist brake command to the main hoist brake control proportional valve 62 so that the falling speed of the hammer grab 10 falls within a predetermined speed allowable range. This prevents the falling speed of the hammer grab 10 from becoming excessively high.

[0203] [Other variations] The present disclosure is not limited to the above-described embodiment. The present disclosure includes, for example, the following aspects.

[0204] (A) Landing Judgment Indicators When it is necessary to take water in the casing into consideration (when the landing judgment mode is set to the water consideration mode), the controller may determine whether the hammer grab has landed using the height information without using the load value. Also, when it is not necessary to take water in the casing into consideration (when the landing judgment mode is set to the non-consideration mode), the controller may determine whether the hammer grab has landed using the load value without using the height information.

[0205] (B) Height detector In the above embodiment, the height detector includes a drum rotation detector 102 that detects the amount of rotation of the winch drum that correlates with the height of the hammer grab 10. However, the height detector is not limited to the drum rotation detector 102 as long as it can obtain height information that correlates with the height of the hammer grab.

[0206] (C) Specifications of excavation machinery (cranes) The excavation machine according to the embodiment shown in FIG. 1 does not have a jib and a strut, but the specifications of the excavation machine are not limited to those shown in FIG. 1. The excavation machine according to the present disclosure may be a luffing crane equipped with a jib, a front strut, and a rear strut, or may be a fixed jib crane equipped with a jib and one strut. The excavation machine according to the present disclosure may be a crane equipped with a mast instead of a gantry (e.g., a large crane). The excavation machine according to the present disclosure may be a crane equipped with a telescopic boom. Examples of cranes equipped with a telescopic boom include rough terrain cranes equipped with tires and telescopic boom crawler cranes equipped with crawlers.

[0207] (D) About the controller The operating device according to the present disclosure may be appropriately selected depending on the type of the main winch and the auxiliary winch and their drive devices. For example, each of the main winch lever input detector 51B of the main winch operating device 51 and the auxiliary winch lever input detector 53B of the auxiliary winch operating device 53 shown in Figures 2 and 3 may be composed of a remote control valve that outputs a pilot pressure according to the lever operation and a pressure sensor that detects the secondary pressure of this remote control valve.

[0208] (E) About winches The main winch and the auxiliary winch according to the present disclosure may be, for example, electric winches. In this case, the hydraulic circuit shown in Fig. 1 can be replaced with an electric circuit (for example, a circuit including an inverter) that drives the electric winch.

[0209] (F) Main and auxiliary volumes In the above embodiment, the body 10A and the grab 10B of the hammer grabbing device 10 are suspended from the main hoisting wire rope R1 that is reeled out from the main hoisting drum DR1, but they may be suspended from the auxiliary hoisting wire rope R2 that is reeled out from the auxiliary hoisting drum DR2. In this case, the crown 10C of the hammer grabbing device 10 is suspended from the main hoisting wire rope R1. In other words, the excavation control device according to the present disclosure also includes modified examples in which components related to "auxiliary hoisting" perform the functions performed by components related to "main hoisting" in the above embodiment.

[0210] (G) Water landing speed control The controller 101 may further perform water landing speed control to reduce the impact when the hammer lands on water. Specifically, for example, when the landing judgment mode is the water consideration mode, the controller 101 performs control to adjust the braking force on the main hoisting drum DR1 so that the falling speed of the hammer grabbing device 10 falls within a predetermined water landing speed allowable range (impact force adjustment control). [Explanation of symbols]

[0211] 10: Hammer Grab 10B: Glove 11: Casing 12: Bottom 100: Excavation control device 101: Controller 102: Drum rotation detector 102A: Main winding rotation sensor 104: Rotation angle detector 105: Elevation angle detector 107: Monitor switch 108: Load value detector 200: Excavation machinery 201: Lower body 202: Upper rotating body 204: Undulating members DR1: Main hoist drum (winch drum in this disclosure) R1: Main winding wire rope (wire rope in this disclosure)

Claims

1. 1. An excavation control device for an excavation machine that performs excavation work in which a wire rope for suspending a hammer grab is unwound from a winch drum to drop the hammer grab to the bottom of a cylindrical casing, a height detector for obtaining height information correlating to the height of the hammergrab; a load value detector for acquiring a load value correlated to the weight of the hammer grab; A controller for determining whether the hammer grab has landed, The controller: When the water in the casing is taken into consideration in the landing judgment, it is judged whether or not the hammer grab has landed using the height information, When the water inside the casing is not taken into consideration in the landing determination, the excavation control device determines whether or not the hammer grab has landed using the load value.

2. a water information provider that provides water information, which is information about the water in the casing, to the controller; The excavation control device according to claim 1 , wherein the controller sets the landing determination mode to a mode that takes into account water in the casing or a mode that does not take into account water in the casing based on the water information.

3. 2. The excavation control device according to claim 1, wherein the controller determines whether the hammer grab has landed by using both the load value and the height information when water in the casing is not taken into consideration in the landing determination.

4. The excavation control device according to claim 1 , wherein the controller performs brake control to stop rotation of the winch drum when it is determined that the hammer grab has landed.

5. The height detector includes a drum rotation detector for detecting an amount of rotation of the winch drum, The excavation control device according to claim 1 , wherein the controller calculates a height of the hammer grab using the amount of rotation.

6. 6. The excavation control device according to claim 5, wherein when water in the casing is taken into account in the landing determination, the controller performs control to adjust a braking force on the winch drum so as to suppress slack in the wire rope when the hammer grab falls through the water.

7. The controller: determining a ground clearance height, which is a height position when the hammer grab leaves the bottom, based on a load value change caused by the wire rope being wound around the winch drum from a state in which the hammer grab is in contact with the bottom; The excavation control device according to claim 5 , wherein the height of the hammer grab is calculated using the height above ground and the amount of rotation.

8. The excavation control device according to claim 1, wherein when the water in the casing is not taken into account in the landing determination, the controller performs control to adjust the braking force on the winch drum so that the falling speed of the hammer grab falls within a predetermined speed tolerance range.

9. A weight setting input unit is further provided for receiving an input from an operator, The excavation control device according to claim 1 , wherein the controller sets a weight of the hammer grab using the load value at the time when the weight setting input device receives the input.

10. 2. The excavation control device according to claim 1, wherein the controller determines a timing of landing of the hammer grab and a timing of leaving the ground when the hammer grab leaves the bottom by using the load value acquired by the load value detector, and acquires an initial value of the height of the hammer grab and a characteristic related to a delay of the load value detector by using a relative position of the height position of the hammer grab at the timing of landing with respect to a reference height position, a relative position of the height position of the hammer grab at the timing of leaving the ground with respect to the reference height position, and a rate of change of the height of the hammer grab.

11. 2. The excavation control device according to claim 1, wherein the controller determines a timing of the hammer grab landing and a timing of the hammer grab leaving the bottom by using the load value acquired by the load value detector, and acquires an error caused by a wire rope length and a characteristic related to a delay of the load value detector by using a relative position of a height position of the hammer grab at the landing timing with respect to a reference height position, a relative position of a height position of the hammer grab at the ground leaving timing with respect to the reference height position, and a rate of change of a height of the hammer grab.

12. The lower body and An upper rotating body rotatably supported on the lower body; A raising and lowering member supported on the upper rotating body so as to be capable of raising and lowering; The wire rope; The winch drum; The hammer grab; An excavation machine comprising: an excavation control device according to any one of claims 1 to 11.

13. The excavation control device includes: a rotation angle detector for acquiring a rotation angle of the upper rotating body relative to the lower body; a hoisting angle detector for acquiring a hoisting angle which is an angle of the hoisting member relative to the upper rotating body, The excavating machine according to claim 12 , wherein the controller determines whether or not the swing angle and the hoisting angle are within an allowable operation range permitted for the excavating operation.

14. 14. The excavating machine according to claim 13, wherein the controller allows automatic control of at least a part of the excavation operation when the swing angle and the hoisting angle are within the permissible operation ranges, and suspends execution of the automatic control when the swing angle and the hoisting angle are not within the permissible operation ranges.

15. A method for controlling an excavating machine that performs excavation work in which a wire rope for suspending a hammer grab is unwound from a winch drum to drop the hammer grab to the bottom of a cylindrical casing, comprising: When water in the casing is taken into consideration in determining whether the hammer grab has landed, height information correlating with the height of the hammer grab is used to determine whether the hammer grab has landed; when water in the casing is not taken into consideration in the landing determination, determining whether or not the hammer grab has landed using a load value correlated with a weight of the hammer grab.

Images