Bucket control device and construction machinery

Abstract

This invention provides a bucket control device that allows users to understand the status of a bucket device even in work sites where it is difficult to visually inspect the bucket device. [Solution] The controller 70, which controls the opening, closing, and raising / lowering of the bucket device 10, determines the open / closed state of the bucket device 10 and notifies the operator of the determined open / closed state of the bucket device 10 via a monitor 120 or the like. Therefore, even in work sites where it is difficult to visually inspect the bucket device 10, the operator can understand the status of the bucket device 10.

Description

Technical Field

[0001] The present disclosure relates to a bucket control device that opens, closes, raises, and lowers a bucket device mounted on a construction machine such as a crane.

Background Art

[0002] Patent Document 1 and Patent Document 2 describe a bucket control device mounted on a construction machine, which includes a first winch drum that pays out and winds up a first winch rope, a second winch drum that pays out and winds up a second winch rope, and a bucket device that is connected to the first winch rope and the second winch rope and can be opened, closed, raised, and lowered according to the rotation of the first winch drum and the rotation of the second winch drum.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, at a work site where it is difficult to visually check the state of the bucket device, it is difficult to grasp the current state of the bucket device, so there is room for improvement.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a bucket control device that can grasp the state of the bucket device even at a work site where it is difficult to visually check the bucket device.

Means for Solving the Problems

[0006] A bucket control device according to the first embodiment is a bucket control device for a construction machine comprising: a first winch drum for paying out and winding up a first winch rope; a second winch drum for paying out and winding up a second winch rope; and a bucket device connected to the first winch rope and the second winch rope, which can be opened and closed and raised and lowered in accordance with the rotation of the first winch drum and the second winch drum, the bucket control device comprising a controller for determining the open / closed state of the bucket device and notifying the operator of the determined open / closed state of the bucket device.

[0007] According to the first embodiment, the open / closed state of the bucket device determined by the controller is communicated to the operator, so that the operator can understand the status of the bucket device even in work sites where it is difficult to visually inspect the bucket device.

[0008] A bucket control device according to a second embodiment preferably has the following additional features compared to a bucket control device according to a first embodiment. That is, in a bucket control device according to a second embodiment, the construction machine includes a first detector that detects a first payout amount, which is the amount of the first winch rope paid out, or a first lifting value of the first winch rope, and a second detector that detects a second payout amount, which is the amount of the second winch rope paid out, or a second lifting value of the second winch rope, and the controller determines the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope, when the bucket device is in a fully open state. The degree of opening and closing of the bucket device is calculated based on the first reference value, which is the difference, and the second reference value, which is the difference when the bucket device is in a fully closed state. Alternatively, the controller calculates the degree of opening and closing of the bucket device based on the difference in lift values ​​between the first lift value of the first winch rope and the second lift value of the second winch rope, the first lift reference value, which is the difference in lift values ​​when the bucket device is in the fully open state, and the second lift reference value, which is the difference in lift values ​​when the bucket device is in the fully closed state.

[0009] According to the second embodiment, a first reference value for when the bucket device is fully open and a second reference value for when the bucket device is fully closed are set in advance, and the degree of opening and closing of the bucket device can be calculated in real time by detecting the first payout amount of the first winch rope and the second payout amount of the second winch rope as needed. Alternatively, a first lifting height reference value for when the bucket device is fully open and a second lifting height reference value for when the bucket device is fully closed are set in advance, and the degree of opening and closing of the bucket device can be calculated in real time by detecting the first lifting height value of the first winch rope and the second lifting height value of the second winch rope as needed.

[0010] A bucket control device according to a third embodiment preferably has the following additional features compared to a bucket control device according to a second embodiment. That is, in a bucket control device according to a third embodiment, the controller presets the first reference value and the second reference value, or the first lifting reference value and the second lifting reference value, and the controller calculates the first reference value from the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in the open state, calculates the second reference value from the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in the closed state, calculates the first lifting reference value from the difference in lifting values ​​between the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in the open state, and calculates the second lifting reference value from the difference in lifting values ​​between the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in the closed state.

[0011] According to the third embodiment, for example, by pre-setting the first reference value and the second reference value before performing the work, the first reference value and the second reference value are set to appropriate values ​​according to the work site, and the accuracy of the calculation of the degree of opening and closing is improved. Similarly, for example, by pre-setting the first lifting height reference value and the second lifting height reference value before performing the work, the first lifting height reference value and the second lifting height reference value are set to appropriate values ​​according to the work site, and the accuracy of the calculation of the degree of opening and closing is improved.

[0012] A bucket control device according to a fourth embodiment preferably further comprises the following features in addition to the bucket control device according to a third embodiment. That is, in a bucket control device according to a fourth embodiment, the first reference value is set to the average of a first reference value set when the lifting height of the bucket device is at a predetermined maximum lifting height and a first reference value set when the lifting height of the bucket device is at a predetermined minimum lifting height; the second reference value is set to the average of a second reference value set when the lifting height of the bucket device is at the maximum lifting height and a second reference value set when the lifting height of the bucket device is at the minimum lifting height; the first lifting height reference value is set to the average of a first lifting height reference value set when the lifting height of the bucket device is at the maximum lifting height and a first lifting height reference value set when the lifting height of the bucket device is at the minimum lifting height; and the second lifting height reference value is set to the average of a second lifting height reference value set when the lifting height of the bucket device is at the maximum lifting height and a second lifting height reference value set when the lifting height of the bucket device is at the minimum lifting height.

[0013] According to the fourth aspect, the first reference value, second reference value, first lifting height reference value, and second lifting height reference value are all set to the average value of the value set when the bucket device is at its maximum lifting height and the value set when the bucket device is at its minimum lifting height. This reduces the influence of changes in the effective radius of the first and second winch drums due to changes in the winding layers of the first and second winch drums. As a result, the calculation accuracy of the opening and closing degree of the bucket device is further improved.

[0014] A bucket control device according to the fifth embodiment preferably has the following additional features in addition to the bucket control device according to any of the first to fourth embodiments. That is, in the bucket control device according to the fifth embodiment, the controller calculates a first change amount which is the difference between the first payout amount of the first winch rope when the bucket device is in the open state and the first payout amount of the first winch rope when the bucket device is in the closed state, and a second change amount which is the difference between the second payout amount of the second winch rope when the bucket device is in the open state and the second payout amount of the second winch rope when the bucket device is in the closed state. If the first change amount is greater than the second change amount, the controller determines that the first winch rope is the rope responsible for opening and closing the bucket device, and if the first change amount is less than the second change amount, the controller determines that the second winch rope is the rope responsible for opening and closing the bucket device.

[0015] According to the fifth embodiment, the rope responsible for opening and closing the bucket device can be determined from the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in a fully open state, and the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in a fully closed state.

[0016] A bucket control device according to the sixth embodiment preferably has the following additional features compared to a bucket control device according to any of the first to fourth embodiments. That is, in a bucket control device according to the sixth embodiment, the controller calculates a first lift change amount, which is the difference between the first lift value of the first winch rope when the bucket device is in the fully open state and the first lift value of the first winch rope when the bucket device is in the fully closed state, and a second lift change amount, which is the difference between the second lift value of the second winch rope when the bucket device is in the fully open state and the second lift value of the second winch rope when the bucket device is in the fully closed state. If the first lift change amount is greater than the second lift change amount, the controller determines that the first winch rope is responsible for opening and closing the bucket device, and if the first lift change amount is less than the second lift change amount, the controller determines that the second winch rope is responsible for opening and closing the bucket device.

[0017] According to the sixth aspect, the rope responsible for opening and closing the bucket device can be determined from the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in a fully open state, and from the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in a fully closed state.

[0018] A construction machine equipped with a bucket control device according to the seventh embodiment comprises the first winch drum, the second winch drum, the bucket device, and a bucket control device according to any of the first to sixth embodiments.

[0019] According to the seventh embodiment, a construction machine equipped with a bucket control device is provided, in which the open / closed state of the bucket device determined by the controller is notified to the operator, and the operator can grasp the status of the bucket device even in a work site where it is difficult to visually inspect the bucket device. [Effects of the Invention]

[0020] According to the present disclosure, it is possible to provide a bucket control device and a construction machine that can grasp the state of the bucket device even at a work site where the bucket device is difficult to visually observe.

Brief Description of the Drawings

[0021] [Figure 1] It is a side view showing a crane equipped with a bucket control device according to an embodiment of the present disclosure. [Figure 2] It is a block diagram showing an outline of the functional configuration of the crane. [Figure 3] It is a diagram showing a hydraulic circuit provided in the crane. [Figure 4] It is a diagram for explaining the opening and closing operation of the bucket device provided in the crane. [Figure 5] It is a block diagram explaining a main part of the control function of the controller. [Figure 6] It is a diagram showing the state of the bucket device in the fully open state and the fully closed state. [Figure 7] It is a diagram showing an example of the change in the opening and closing degree of the bucket device during the operation of the crane. [Figure 8] It is an example of a screen showing the opening and closing degree of the bucket device displayed on the monitor. [Figure 9] It is an example of an image displayed on the monitor when setting the fully open state and the fully closed state of the bucket device. [Figure 10] It is a diagram showing the state where the bucket device is at the maximum lifting height and the state where the bucket device is at the minimum lifting height. [Figure 11] It is an example of an image displayed on the monitor when moving the bucket device to the maximum lifting height and the minimum lifting height. [Figure 12] It is a flowchart showing the control operation executed when determining the rope responsible for opening and closing the bucket device. [Figure 13] It is an example of an image displayed on the monitor when checking whether the determination result of the rope responsible for opening and closing is correct. [Figure 14]This flowchart explains the controller's control operations, which are performed when setting the maximum and minimum relative differences, and when determining the rope responsible for opening and closing the bucket device. [Modes for carrying out the invention]

[0022] Preferred embodiments of this disclosure will be described with reference to the drawings.

[0023] [First Embodiment] Figure 1 shows a crane 100, which is a construction machine according to the above embodiment. This crane 100 comprises a lower body 101, an upper slewing body 102 that is rotatably supported on the lower body 101, a luffing member 104 that is luffably supported on the upper slewing body 102, a first point sheave 105 and a second point sheave 106 attached to the tip of the luffing member 104, a plurality of winches arranged on the lower body 101 or the upper slewing body 102, a bucket device 10, and a bucket control device.

[0024] The lower body 101 is equipped with a travel device, such as a crawler track, and is configured to be self-propelled. However, the lower body may be composed of a structure such as a support base that rotatably supports the upper slewing body 102 and is not self-propelled. The upper slewing body 102 comprises a slewing frame 103 rotatably attached to the lower body 101, a cabin supported at the front of the slewing frame 103, and a counterweight supported at the rear of the slewing frame 103. The plurality of winches include a first winch WC1, a second winch WC2, and a luffing winch WC3.

[0025] The luffing member 104 consists of a boom supported on a slewing frame 103 so as to be luffable. However, the luffing member may also include a boom and a jib rotatably supported at the tip of the boom. A gantry 107 is erected on the slewing frame 103. A lower spreader 110 is positioned at the upper end of the gantry 107. One end of a guy line 108 is connected to the tip of the luffing member 104, and the other end of the guy line 108 is connected to an upper spreader 109. The lower spreader 110 and the upper spreader 109 are spaced apart from each other. A luffing rope 111 is wrapped around the lower spreader 110 and the upper spreader 109. The luffing winch WC3 is positioned on the slewing frame 103 and has a winch drum DR3 around which the luffing rope 111 is wound. The luffing winch WC3 reduces or increases the distance between the upper spreader 109 and the lower spreader 110 by winding in or unwinding the luffing rope 111. The luffing member 104 is raised or lowered in accordance with the reduction or increase in this distance.

[0026] Figure 2 is a block diagram showing the functional configuration of the bucket control device. Figure 3 is a diagram showing the hydraulic circuit provided by the crane 100.

[0027] The first winch WC1 and the second winch WC2 are driven to open, close, and raise the bucket device 10. Specifically, as shown in Figures 1 to 3, the first winch WC1 has a first winch drum DR1 around which the first winch rope R1 is wound, a first winch motor 34 connected to the first winch drum DR1, a first clutch brake 40A, and a reduction gear 47. Similarly, the second winch WC2 has a second winch drum DR2 around which the second winch rope R2 is wound, a second winch motor 35 connected to the second winch drum DR2, a second clutch brake 40B, and a reduction gear 47. The first winch rope R1 is an opening and closing rope for opening and closing the bucket device 10, and the second winch rope R2 is a support rope for supporting the bucket device 10. The first winch drum DR1 is an opening / closing drum that pays out and retracts the first winch rope R1 (opening / closing rope), and the second winch drum DR2 is a support drum that pays out and retracts the second winch rope R2 (support rope).

[0028] The first winch drum DR1 is supported by a support member (not shown) so as to be rotatable around a horizontal axis, allowing for the unwinding and winding of the first winch rope R1. The second winch drum DR2 is supported by a support member (not shown) so as to be rotatable around a horizontal axis, allowing for the unwinding and winding of the second winch rope R2.

[0029] The first point sheave 105 and the second point sheave 106 are arranged side by side and attached to the tip of the luffing member 104. The first winch rope R1 is wound around the first point sheave 105 and hangs down from the first point sheave 105. The second winch rope R2 is wound around the second point sheave 106 and hangs down from the second point sheave 106. The lower ends (tips) of the first and second winch ropes R1 and R2 are connected to the bucket device 10.

[0030] The bucket device 10 is a working device known as a clamshell bucket. The bucket device 10 is connected to the first winch rope R1 and the second winch rope R2, and can be opened and closed and raised and lowered in accordance with the rotation of the first winch drum DR1 and the second winch drum DR2. The right diagram of Figure 4 shows the bucket device 10 in the open state, and the left diagram of Figure 4 shows the bucket device 10 in the closed state. The bucket device 10 comprises an upper member 11, a lower member 16 positioned below the upper member 11, a pair of link members 12, 12, a pair of buckets 13, 13, a lower sheave 14, and an upper sheave 15.

[0031] The pair of link members 12, 12 are arranged horizontally, spaced apart from each other. The upper ends of the pair of link members 12, 12 are connected to the upper member 11 so as to be rotatable around a horizontal axis. One lower end of the pair of link members 12, 12 is connected to one of the pair of buckets 13, 13 so as to be rotatable around a horizontal axis, and the other lower end of the pair of link members 12, 12 is connected to the other of the pair of buckets 13, 13 so as to be rotatable around a horizontal axis.

[0032] The lower sheave 14 is supported by the lower member 16 so as to be rotatable around a horizontal axis. Each of the pair of buckets 13, 13 has a supported portion that is supported by the lower member 16 so as to be rotatable around a horizontal axis. The upper sheave 15 is supported by the upper member 11 so as to be rotatable around a horizontal axis.

[0033] The pair of buckets 13, 13 have a storage space capable of accommodating materials to be transported, such as soil and sand. The pair of buckets 13, 13 can rotate around the supported part, allowing them to be displaced between a state where the lower ends of the buckets 13, 13 are adjacent to each other (the closed state) and a state where the lower ends of the buckets 13, 13 are separated horizontally (the open state). The pair of link members 12, 12 support the buckets 13, 13 and rotate relative to the upper member 11 in accordance with the displacement of the buckets 13, 13. By maintaining the closed state, the pair of buckets 13, 13 can hold the materials to be transported contained in the storage space. By switching from the closed state to the open state, the pair of buckets 13, 13 can discharge the materials to be transported from the storage space to the outside of the buckets 13, 13.

[0034] The first winch rope R1 is routed around the lower sheave 14 and the upper sheave 15, and the end of the first winch rope R1 is fixed to either the upper member 11 or the lower member 16. The end of the second winch rope R2 is fixed to the upper member 11.

[0035] The first and second winch motors 34 and 35 are variable displacement hydraulic motors connected to the hydraulic pump 31. The first winch motor 34 operates by receiving hydraulic fluid discharged from the hydraulic pump 31 to rotate the first winch drum DR1 in either the forward or reverse direction, i.e., the unwinding direction and the winding direction. Similarly, the second winch motor 35 operates by receiving hydraulic fluid discharged from the hydraulic pump 31 to rotate the second winch drum DR2 in either the forward or reverse direction, i.e., the unwinding direction and the winding direction. This enables the opening and closing and raising and lowering of the bucket device 10 through the cooperation of the first winch WC1 and the second winch WC2. The hydraulic pump 31 is driven by a power source such as an engine (not shown).

[0036] The reduction gear 47 of the first winch WC1 reduces the rotational speed of the first winch motor 34 and transmits the driving force (rotational force) from the first winch motor 34 to the first winch drum DR1. The reduction gear 47 of the second winch WC2 reduces the rotational speed of the second winch motor 35 and transmits the driving force (rotational force) from the second winch motor 35 to the second winch drum DR2. These reduction gears 47 each have, for example, a planetary gear mechanism.

[0037] The first clutch brake 40A can switch between a connected state, in which the driving force of the first winch motor 34 can be transmitted to the first winch drum DR1, and a free state, in which the first winch rope R1 can be unfurled from the first winch drum DR1 by the weight of the bucket device 10. The first clutch brake 40A can adjust the degree of connection between the first winch motor 34 and the first winch drum DR1 between the connected state and the free state.

[0038] Similarly, the second clutch brake 40B can switch between a connected state, in which the driving force of the second winch motor 35 can be transmitted to the second winch drum DR2, and a free state, in which the second winch rope R2 can be unfurled from the second winch drum DR2 by the weight of the bucket device 10. The second clutch brake 40B can adjust the degree of connection between the second winch motor 35 and the second winch drum DR2 between the connected state and the free state.

[0039] The aforementioned connection state is one in which the first and second winch ropes R1 and R2 can be unwound and wound up by the driving force of the first and second winch motors 34 and 35. That is, when the first and second winch motors 34 and 35 are driven in the aforementioned connection state, the driving force of the first and second winch motors 34 and 35 is transmitted to the first and second winch drums DR1 and DR2, respectively, via the reduction gears 47 and 47. When the first and second winch drums DR1 and DR2 rotate, the first and second winch ropes R1 and R2 are unwound or wound up.

[0040] The free state is a state in which the first and second winch ropes R1 and R2 can be unfurled from the first and second winch drums DR1 and DR2 by the tension of the first and second winch ropes R1 and R2, that is, a state in which the bucket device 10 can free fall. In other words, the free state is a state in which the first and second winch ropes R1 and R2 can be unfurled from the first and second winch drums DR1 and DR2 without rotating the first and second winch motors 34 and 35 in the unfurling direction of the first and second winch ropes R1 and R2.

[0041] Furthermore, the first clutch brake 40A can apply a first braking force to the first winch drum DR1, that is, it can brake the first winch drum DR1. Similarly, the second clutch brake 40B can apply a second braking force to the second winch drum DR2, that is, it can brake the second winch drum DR2.

[0042] When the first braking force against the rotation of the first winch drum DR1 exceeds a predetermined magnitude, the first winch drum DR1 is braked, making it impossible to pay out the first winch rope R1 from the first winch drum DR1. Similarly, when the second braking force against the rotation of the second winch drum DR2 exceeds a predetermined magnitude, the second winch drum DR2 is braked, making it impossible to pay out the second winch rope R2 from the second winch drum DR2. Therefore, the first braking force of the first clutch brake 40A and the second braking force of the second clutch brake 40B are sufficient to maintain the bucket device 10 in a stationary state without free fall, and to stop the bucket device 10 if it is free-falling.

[0043] In this embodiment, the first clutch brake 40A and the second clutch brake 40B are each so-called wet brakes and include a piston 42 driven by hydraulic pressure supplied from a pilot hydraulic power source P, 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 fluid.

[0044] The multiple brake discs 41 can be switched between a state in which the multiple brake discs 41 are in contact with each other and a state in which the multiple brake discs 41 are separated from each other by the operation of the piston 42. The first clutch brake 40A and the second clutch brake 40B each enter the free state when the multiple brake discs 41 are separated from each other, thereby allowing the bucket device 10 to descend (free fall) by its own weight. The first clutch brake 40A and the second clutch brake 40B each enter the connected state when the multiple brake discs 41 come into contact with each other.

[0045] More specifically, each of the first clutch brake 40A and the second clutch brake 40B is equipped with a spring 46, and each of the first clutch brake 40A and the second clutch brake 40B has a pair of oil chambers 43, 44 formed therein, and the piston 42 has a flange 45 that separates the pair of oil chambers 43, 44. When the hydraulic pressure applied to the pair of oil chambers 43, 44 from the pilot hydraulic power source P is the same, the spring 46 biases the piston 42 so that the multiple brake discs 41 come into contact with each other. When the hydraulic pressure applied to one oil chamber 44 from the pilot hydraulic power source P becomes greater than the hydraulic pressure applied to the other oil chamber 43 by a predetermined amount or more, the multiple brake discs 41 come apart from each other.

[0046] The bucket control device is a device for opening, closing, and raising / lowering the bucket device 10 by controlling the drive of the first winch drum DR1 and the second winch drum DR2. This bucket control device comprises a first control valve 32, a second control valve 33, a first payout proportional valve 61A, a first winding proportional valve 61B, a second payout proportional valve 63A, a second winding proportional valve 63B, a first brake proportional valve 62, a second brake proportional valve 64, a plurality of operating devices, and a controller 70. In this embodiment, each of the proportional valves 61A, 61B, 62, 63A, 63B, and 64 is an electromagnetic proportional pressure reducing valve.

[0047] The first control valve 32 is interposed between the hydraulic pump 31 and the first winch motor 34, and the second control valve 33 is interposed between the hydraulic pump 31 and the second winch motor 35. Each of the first and second control valves 32 and 33 is composed of a hydraulic pilot switching valve having a pair of pilot ports.

[0048] The pair of pilot ports are a pay-out pilot port and a retraction pilot port. When no pilot pressure is applied to either of the pilot ports, the first and second control valves 32 and 33 are held in a neutral position, disconnecting the winch motor corresponding to the control valve (hereinafter referred to as the "corresponding winch motor") among the first and second winch motors 34 and 35 from the hydraulic pump 31.

[0049] Each of the first and second control valves 32 and 33 opens when pilot pressure is applied to the unwinding pilot port to form an oil passage for rotating the corresponding winch motor in the unwinding direction, that is, an oil passage for supplying hydraulic fluid from the hydraulic pump 31 to the corresponding winch motor in the unwinding direction. Each of the first and second control valves 32 and 33 opens when pilot pressure is applied to the rewinding pilot port to form an oil passage for rotating the corresponding winch motor in the rewinding direction, that is, an oil passage for supplying hydraulic fluid from the hydraulic pump 31 to the corresponding winch motor in the rewinding direction. The opening degree of each of the first and second control valves 32 and 33 increases with increasing pilot pressure to allow hydraulic fluid to flow at a flow rate corresponding to the pilot pressure input to the control valve.

[0050] The first dispensing proportional valve 61A is interposed between a pilot hydraulic power source (not shown) and the dispensing pilot port of the first control valve 32. When a first dispensing command, which is an electrical signal, is input to the proportional valve 61A from the controller 70, the valve opens to allow a pilot pressure proportional to the first dispensing command to be input to the dispensing pilot port. The first retracting proportional valve 61B is interposed between the pilot hydraulic power source and the retracting pilot port of the first control valve 32. When a first retracting command, which is an electrical signal, is input to the proportional valve 61B from the controller 70, the valve opens to allow a pilot pressure proportional to the first retracting command to be input to the retracting pilot port.

[0051] Similarly, the second dispensing proportional valve 63A is interposed between a pilot hydraulic power source (not shown) and the dispensing pilot port of the second control valve 33, and opens to allow a pilot pressure proportional to the second dispensing command to be input to the dispensing pilot port when the controller 70 inputs a second dispensing command, which is an electrical signal, to the proportional valve 63A. The second retracting proportional valve 63B is interposed between the pilot hydraulic power source and the retracting pilot port of the second control valve 33, and opens to allow a pilot pressure proportional to the second retracting command to be input to the retracting pilot port when the controller 70 inputs a second retracting command, which is an electrical signal, to the proportional valve 63B.

[0052] As described above, the first control valve 32, the first dispensing proportional valve 61A, and the first retracting proportional valve 61B constitute a first speed controller that changes the flow rate and direction of the hydraulic fluid flowing into the first winch motor 34 in response to commands input to the proportional valves 61A and 61B. In other words, the first speed controller changes the speed at which the first winch motor 34 rotates the first winch drum DR1. Similarly, the second control valve 33, the second dispensing proportional valve 63A, and the second retracting proportional valve 63B constitute a second speed controller that changes the flow rate and direction of the hydraulic fluid flowing into the second winch motor 35 in response to commands input to the proportional valves 63A and 63B. In other words, the second speed controller changes the speed at which the second winch motor 35 rotates the second winch drum DR2.

[0053] The first brake proportional valve 62 is interposed between the pilot hydraulic power source P and the first clutch brake 40A. When the first brake command, which is an electrical signal, is input to the proportional valve 62 from the controller 70, the valve opens to allow hydraulic pressure (first pilot pressure) proportional to the first brake command to be input to the oil chamber 43 of the first clutch brake 40A. As a result, the first brake proportional valve 62 can switch the state of the first clutch brake 40A between the free state and the connected state.

[0054] Similarly, the second brake proportional valve 64 is interposed between the pilot hydraulic power source P and the second clutch brake 40B. When a second brake command, which is an electrical signal, is input to the proportional valve 64 from the controller 70, the valve opens to allow hydraulic pressure (second pilot pressure) proportional to the second brake command to be input to the oil chamber 43 of the second clutch brake 40B. As a result, the second brake proportional valve 64 can switch the state of the second clutch brake 40B between the free state and the connected state.

[0055] The multiple operating devices include a first winch operating device 51, a second winch operating device 53, a first brake operating device 52, and a second brake operating device 54. The first winch operating device 51 has a first winch operating lever 51A and a first winch operating device body 51B. The second winch operating device 53 has a second winch operating lever 53A and a second winch operating device body 53B. The first brake operating device 52 has a first brake operating pedal 52A and a first brake operating device body 52B. The second brake operating device 54 has a second brake operating pedal 54A and a second brake operating device body 54B.

[0056] In the following description, the first winch rope R1 may be referred to as the main hoisting rope, the second winch rope R2 as the auxiliary hoisting rope, the first winch drum DR1 as the main hoisting drum, and the second winch drum DR2 as the auxiliary hoisting drum. Also, the first winch operating lever 51A may be referred to as the main hoisting lever, and the second winch operating lever 53A as the auxiliary hoisting lever. Also, the first brake operating pedal 52A may be referred to as the main hoisting pedal, and the second brake operating pedal 54A as the auxiliary hoisting pedal. In the crane 100, instead of the bucket device 10, a main hoisting hook (not shown) may be attached to the end of the first winch rope R1 (main hoisting rope), and an auxiliary hoisting hook (not shown) may be attached to the end of the second winch rope R2 (auxiliary hoisting rope). "Main slings" are primarily used for heavy loads, such as for lifting heavy loads, while "supplementary slings" are primarily used as auxiliary slings for lifting lighter loads.

[0057] The first winch operating lever 51A is an operating member to which a first rotational operation is performed by the operator to specify the drive speed (rotational speed) of the first winch drum DR1. Specifically, the first winch operating lever 51A is provided with either a first unwinding operation to rotate the first winch drum DR1 in the unwinding direction to unwind the first winch rope R1, or a first winding operation to rotate the first winch drum DR1 in the winding direction to wind up the first winch rope R1, as the first rotational operation.

[0058] The first winch operating device body 51B inputs a command signal to the controller 70 to command a rotational speed corresponding to the amount of operation (lever operation amount) of the first rotation operation (first payout operation or first winding operation) applied to the first winch operating lever 51A.

[0059] Similarly, the second winch operating lever 53A is an operating member to which a second rotational operation is performed by the operator to specify the drive speed (rotational speed) of the second winch drum DR2. Specifically, the second winch operating lever 53A is provided with either a second payout operation to rotate the second winch drum DR2 in the payout direction to pay out the second winch rope R2, or a second winding operation to rotate the second winch drum DR2 in the winding direction to wind up the second winch rope R2, as the second rotational operation.

[0060] The second winch operating device body 53B inputs a command signal to the controller 70 to command a rotational speed corresponding to the amount of operation (lever operation amount) of the second rotation operation (second payout operation or second winding operation) applied to the second winch operating lever 53A.

[0061] The first brake operation pedal 52A is an operating member to which the operator performs a pedal operation (an example of a first brake operation) to specify the first brake force to the first winch drum DR1. The first brake operation device body 52B inputs a command signal to the controller 70 to command a brake force of a magnitude corresponding to the amount of the first pedal operation (pedal operation amount) applied to the first brake operation pedal 52A.

[0062] The second brake operation pedal 54A is an operating member to which the operator performs a pedal operation (an example of a second brake operation) to specify the second brake force applied to the second winch drum DR2. The second brake operation device body 54B inputs a command signal to the controller 70 to command a brake force of a magnitude corresponding to the amount of the second pedal operation (pedal operation amount) applied to the second brake operation pedal 54A.

[0063] The bucket control device further includes, as shown in Figure 2, a first rotation sensor 81, a second rotation sensor 82, and a control mode setting unit. In this embodiment, the control mode setting unit includes a non-synchronized control mode switch 90 (single-sided on / off switch 90) and a bucket assist mode switch 91.

[0064] The first rotation sensor 81 generates a first detection signal for the first rotation amount nm, which is the amount of rotation of the first winch drum DR1, and inputs it to the controller 70. The second rotation sensor 82 generates a second detection signal for the second rotation amount na, which is the amount of rotation of the second winch drum DR2, and inputs it to the controller 70. The first rotation amount nm and the second rotation amount na are rotation amounts from a set reference value, respectively. Note that the first rotation sensor 81 may be a sensor that generates a detection signal for the amount of rotation of the first point sheave 105 instead of the amount of rotation of the first winch drum DR1, and the second rotation sensor 82 may be a sensor that generates a detection signal for the amount of rotation of the second point sheave 106 instead of the amount of rotation of the second winch drum DR2.

[0065] In this embodiment, the controller 70 sets the control mode of the controller 70 to one of a predetermined number of control modes based on a command signal input from the control mode setting unit. In this embodiment, the number of control modes includes a bucket assist mode and a non-assist mode, and the bucket assist mode includes a synchronized control mode and a non-synchronized control mode. The number of control modes may further include other control modes.

[0066] The bucket assist mode is a control mode in which the controller 70 performs assist control to enable the operator to perform at least one of the operations of opening / closing and raising / lowering the bucket device 10 with simple operation. The non-assist mode is a control mode in which the above-mentioned assist control is not performed. Assist control includes main auxiliary synchronization control and free synchronization control.

[0067] In this embodiment, the control mode is set to bucket assist mode when the bucket assist mode switch 91 is ON, and the control mode is set to non-assist mode when the bucket assist mode switch 91 is OFF. In bucket assist mode, the control mode is set to non-synchronized control mode when the non-synchronized control mode switch 90 is ON, and the control mode is set to synchronized control mode when the non-synchronized control mode switch 90 is OFF.

[0068] In this embodiment, synchronization control such as main and auxiliary synchronization control and free synchronization control is performed in the synchronization control mode. The operation of the bucket device 10 in the synchronization control mode includes the operation of "closed up," which is the operation of raising the bucket device 10 in the closed state; the operation of "opened up," which is the operation of raising the bucket device 10 in the open state; the operation of "opened down," which is the operation of lowering the bucket device 10 in the open state; and the operation of "closed down," which is the operation of lowering the bucket device 10 in the closed state. In the non-synchronized control mode, the above-mentioned main and auxiliary synchronization control and free synchronization control are not performed. That is, in the non-synchronized control mode, the raising and lowering and opening and closing of the bucket device 10 are performed by manual operation by the driver.

[0069] Figure 5 is a block diagram illustrating the main components of the control function of the controller 70. The controller 70 controls the driving of the first winch WC1 and the second winch WC2 to open, close, and raise / lower the bucket device 10. The controller 70 has a computer including a central processing unit (such as a CPU) and a storage unit 78 consisting of ROM and RAM, and performs various processes including opening, closing, and raising / lowering the bucket device 10. The controller 70 has an opening / closing state determination unit 71, a screen display control unit 72, a brake force adjustment unit 75, a drum operation control unit 76, a condition setting unit 77, a storage unit 78, and an opening / closing rope determination unit 79. These functions are performed by the processing unit executing a control program stored in the storage unit 78.

[0070] The controller 70 receives various command signals, including the first rotation amount nm of the first winch drum DR1 detected by the first rotation sensor 81, the second rotation amount na of the second winch drum DR2 detected by the second rotation sensor 82, an ON command signal that switches the control mode output from the non-synchronized control mode switch 90 to non-synchronized control mode, an ON command signal that switches the control mode output from the bucket assist mode switch 91 to bucket assist mode, and an ON command signal that activates the monitor 120 (described later) output from the monitor switch 92.

[0071] Furthermore, the controller 70 receives command signals corresponding to the operator's operations (operator operations in Figure 5). Specifically, the controller 70 receives command signals corresponding to the operator's lever operation amount output from the first winch operating device body 51B, command signals corresponding to the operator's lever operation amount output from the second winch operating device body 53B, command signals corresponding to the operator's brake operation amount output from the first brake operating device body 52B, and command signals corresponding to the operator's brake operation amount output from the second brake operating device body 54B (see Figure 2).

[0072] The controller 70 outputs command signals to various proportional valves (61A, 61B, 62, 63A, 63B, 64) calculated by the brake force adjustment unit 75 and the drum motion control unit 76, as well as command signals related to the screen display of the monitor 120.

[0073] [Method for calculating the degree of opening / closing α] The controller 70 has the function of determining the open / closed state of the bucket device 10 and notifying the operator of the determined open / closed state of the bucket device 10. The open / closed state of the bucket device 10 is determined based on the degree of open / closed α of the bucket device 10. The open / closed state determination unit 71 calculates the degree of open / closed α of the bucket device 10 and determines the open / closed state of the bucket device 10. The open / closed state determination unit 71 calculates the degree of open / closed α from the following equation (1). In equation (1), ΔL is the difference between the first payout amount Lm of the first winch rope R1 and the second payout amount La of the second winch rope R2 (hereinafter, relative difference ΔL), and is calculated from the following equation (2). In the following explanation, the first payout amount Lm of the first winch rope R1 and the second payout amount La of the second winch rope R2 are assumed to be positive when the bucket device 10 is lowered (i.e., when the bucket device 10 is descending), and the signs of the first payout amount Lm and the second payout amount La are assumed to be negative when the bucket device 10 is raised (i.e., when the bucket device 10 is ascending).

[0074] α=(ΔL-ΔLmin) / (ΔLmax-ΔLmin)×100 (1) ΔL = Lm - La ···(2)

[0075] In equation (1), ΔLmax is the relative difference (hereinafter referred to as the maximum relative difference ΔLmax) between the amount Lm of the first winch rope R1 and the amount La of the second winch rope R2 when the bucket device 10 is fully open (hereinafter referred to as the fully open state). Also, ΔLmin is the relative difference (hereinafter referred to as the minimum relative difference ΔLmin) between the amount Lm of the first winch rope R1 and the amount La of the second winch rope R2 when the bucket device 10 is fully closed (hereinafter referred to as the fully closed state). The maximum relative difference ΔLmax and the minimum relative difference ΔLmin are values ​​set in advance by the operator.

[0076] The opening / closing state determination unit 71 calculates the degree of opening / closing α of the bucket device 10 by applying the relative difference ΔL, which is calculated as needed, the maximum relative difference ΔLmax, which is set when the bucket device 10 is in a fully open state, and the minimum relative difference ΔLmin, which is set when the bucket device 10 is in a fully closed state, to equation (1). From equation (1), it is normalized so that when the relative difference ΔL is the maximum relative difference ΔLmax, the degree of opening / closing α is 100%, and when the relative difference ΔL is the minimum relative difference ΔLmin, the degree of opening / closing α is 0%.

[0077] Figure 6 shows the state of the bucket device 10 in the fully open and fully closed states. The right diagram in Figure 6 shows the fully open state, and the left diagram in Figure 6 shows the fully closed state. In the fully open state of the bucket device 10 shown in the right diagram of Figure 6, the first winch rope R1 is loose, and the bucket device 10 is supported by the second winch rope R2. At this time, the lower ends of the pair of buckets 13 of the bucket device 10 are furthest apart. As the first winch rope R1 is wound up from this state, the first winch rope R1 becomes taut, and as the first winch rope R1 is further wound up, the bucket device 10 is gradually closed. When the bucket device 10 is completely closed, it is in the state shown in the left diagram of Figure 6, where the first winch rope R1 is taut, while the second winch rope R2 is loose. At this time, the bucket device 10 is supported by the first winch rope R1, and the lower ends of the pair of buckets 13 of the bucket device 10 are adjacent to each other. The relative difference ΔL increases as the bucket device 10 transitions from a closed state to an open state, and the maximum relative difference ΔLmax in the fully open state becomes greater than the minimum relative difference ΔLmin in the fully closed state.

[0078] Here, it is preferable that the maximum relative difference ΔLmax is set based on the state in which the bucket device 10 is fully open as shown in the right diagram of Figure 6, and there is almost no slack in the first winch rope R1. It is also preferable that the minimum relative difference ΔLmin is set based on the state in which the bucket device 10 is fully closed as shown in the left diagram of Figure 6, and there is almost no slack in the second winch rope R2. The maximum relative difference ΔLmax and the minimum relative difference ΔLmin are set in advance by the operator and then stored, for example, in a memory unit 78 built into the controller 70. Alternatively, the maximum relative difference ΔLmax and the minimum relative difference ΔLmin may be stored in a memory unit provided separately from the controller 70. The method for setting the maximum relative difference ΔLmax and the minimum relative difference ΔLmin will be described later. Note that the maximum relative difference ΔLmax corresponds to the first reference value of this disclosure, and the minimum relative difference ΔLmin corresponds to the second reference value of this disclosure.

[0079] The first payout amount Lm of the first winch rope R1 is estimated from the following equation (3). In equation (3), Rm is the design effective radius of the first winch drum DR1. In equation (3), nm is the first rotation amount, which is the number of rotations of the first winch drum DR1 from a reference. In equation (3), once the effective radius Rm is set, the first payout amount Lm of the first winch rope R1 is calculated from the first rotation amount nm of the first winch drum DR1 detected by the first rotation sensor 81. Since the first payout amount Lm is calculated from the first rotation amount nm of the first winch drum DR1 detected by the first rotation sensor 81, the first rotation sensor 81 functions as a first detector for detecting the first payout amount in this disclosure.

[0080] Lm = Rm × nm ... (3)

[0081] The second payout amount La of the second winch rope R2 is estimated from the following equation (4). In equation (4), Ra is the design effective radius of the second winch drum DR2. In equation (4), na is the second rotation amount, which is the number of rotations of the second winch drum DR2 from the reference. In equation (4), once the effective radius Ra is set, the second payout amount La of the second winch rope R2 is calculated from the second rotation amount na of the second winch drum DR2 detected by the second rotation sensor 82. Since the second payout amount La is calculated from the second rotation amount na of the second winch drum DR2 detected by the second rotation sensor 82, the second rotation sensor 82 functions as a second detector for detecting the second payout amount in this disclosure.

[0082] La = Ra × na ···(4)

[0083] As a result, the first payout amount Lm of the first winch rope R1 calculated from equation (3) and the second payout amount La of the second winch rope R2 calculated from equation (4) are applied to equation (2) to calculate the relative difference ΔL. Furthermore, the degree of opening and closing α is obtained by applying the relative difference ΔL to equation (1).

[0084] Figure 7 shows an example of the change in the degree of opening / closing α of the bucket device 10 during operation, calculated by equation (1). In Figure 7, the horizontal axis represents time t [sec] and the vertical axis represents the degree of opening / closing α [%]. A degree of opening / closing α of 100% corresponds to the bucket device 10 being fully open and the relative difference ΔL being the preset maximum relative difference ΔLmax. A degree of opening / closing α of 0% corresponds to the bucket device 10 being fully closed and the relative difference ΔL being the preset minimum relative difference ΔLmin.

[0085] In Figure 7, as the bucket device 10 is opened, that is, as the first winch rope R1 is paid out, the first payout amount Lm increases and the degree of opening / closing α increases toward 100%. When the degree of opening / closing α reaches 100%, the bucket device 10 is fully open, and the relative difference ΔL becomes the maximum relative difference ΔLmax. If the bucket device 10 is operated further in the opening direction from this state, that is, as the first winch rope R1 is paid out, slack occurs in the first winch rope R1, and the relative difference ΔL exceeds the maximum relative difference ΔLmax, resulting in an over-open state.

[0086] Furthermore, as the bucket device 10 is closed, that is, as the first winch rope R1 is wound up, the first payout amount Lm decreases and the degree of opening / closing α decreases toward 0%. When the degree of opening / closing α reaches 0%, the bucket device 10 is in a fully closed state, and the relative difference ΔL becomes the minimum relative difference ΔLmin. If the bucket device 10 is operated further in the closing direction from this state, that is, as the first winch rope R1 is wound up, slack occurs in the second winch rope R2, and the relative difference ΔL becomes smaller than the minimum relative difference ΔLmin, resulting in an over-closed state.

[0087] In the over-open state described above, the first winch rope R1 becomes excessively loose, and in the over-closed state described above, the second winch rope R2 becomes excessively loose, which may cause the ropes to become tangled and twisted. Although the over-open and over-closed states can be prevented by visually inspecting the bucket device 10, in some work sites, obstacles may prevent visual inspection of the bucket device 10, making it impossible to ascertain its condition.

[0088] In contrast, in this embodiment, in order to understand the open / closed state of the bucket device 10 even at a work site where the bucket device 10 cannot be seen, the controller 70 notifies the operator of the degree of open / closed state α of the bucket device 10. Specifically, the controller 70 notifies the operator of the open / closed state of the bucket device 10 by displaying the degree of open / closed state α of the bucket device 10 on the monitor 120. The monitor 120 may be, for example, a monitor located inside the cab, or a monitor located outside the cab. For example, when the crane 100 is remotely operated, it is displayed on a monitor located in the remote operation room.

[0089] The screen display control unit 72 acquires the degree of opening / closing α of the bucket device 10 determined (calculated) by the opening / closing state determination unit 71, and displays the acquired degree of opening / closing α of the bucket device 10 on the monitor 120, thereby informing the operator of the degree of opening / closing α of the bucket device 10.

[0090] Figure 8 shows an example of a screen displayed on the monitor 120 based on the control of the screen display control unit 72. The monitor 120 displays the degree of opening / closing α, which is calculated in real time by the opening / closing state determination unit 71. The left side of Figure 8 shows an example of the bucket device 10 with an opening / closing degree α of 60%. The monitor 120 displays the degree of opening / closing α as a number (60%). The monitor 120 also displays the magnitude of the degree of opening / closing α graphically. For example, as shown in Figure 8, the degree of opening / closing α is displayed using a gauge (bar graph). In Figure 8, the longer the gauge is to the right, the larger the degree of opening / closing α is.

[0091] The right-hand diagram in Figure 8 shows an example where the degree of opening / closing α is 110%. The monitor 120 displays the degree of opening / closing α as a number (110%). The magnitude of the degree of opening / closing α is also displayed as a gauge (bar graph) at the top of the monitor 120. As shown in the right-hand diagram in Figure 8, since the degree of opening / closing α is 110%, the gauge display exceeds 100%. In such an over-open state where the degree of opening / closing α exceeds 100%, the operator may be notified of the over-open state by changing the color of the gauge display or flashing the gauge, compared to when the degree of opening / closing α is between 0% and 100%. Similarly, in the case of an over-closed state where the degree of opening / closing α is less than 0%, the operator may be notified of the over-closed state by changing the color of the gauge or flashing the gauge. Furthermore, the screen display control unit 72 may notify the operator that the bucket device 10 is in an over-open or over-closed state by generating a warning sound or voice from the alarm device 126.

[0092] As described above, the display of the opening / closing degree α on the monitor 120 allows the operator to understand the status of the bucket device 10 from the monitor 120, even in work sites where the bucket device 10 cannot be visually inspected. Furthermore, the display of the opening / closing degree α as a diagram makes it easier for the operator to understand the status of the bucket device 10. In addition, if the opening / closing degree α exceeds 100% (over-opening) or the opening / closing degree α falls below 0% (over-closed), the display is changed or an audible alert is generated, allowing the operator to quickly recognize the occurrence of the over-opening or over-closed condition.

[0093] The brake force adjustment unit 75 adjusts the first brake force and the second brake force. When the control mode is set to synchronized control mode, a first brake operation that reduces the first brake force is applied to the first brake operation pedal 52A, and the open / closed state determination unit 71 determines that the bucket device 10 is in the open state, the brake force adjustment unit 75 performs the following open-down control. In the open-down control, the first brake force and the second brake force are controlled so that the bucket device 10 descends by its own weight while maintaining the open state of the bucket device 10. Furthermore, when the control mode is set to synchronized control mode, a first brake operation that reduces the first brake force is applied to the first brake operation pedal 52A, and the open / closed state determination unit 71 determines that the bucket device 10 is in the closed state, the brake force adjustment unit 75 performs the following closed-down control. In the closed-down control, the brake force adjustment unit 75 adjusts the first brake force and the second brake force so that the bucket device 10 descends while maintaining the closed state of the bucket device 10.

[0094] The drum operation control unit 76 controls the operation of the first winch drum DR1 and the second winch drum DR2. In the main auxiliary synchronization control in synchronization control mode, the operation of the first winch drum DR1 and the second winch drum DR2 are controlled based on the first rotational operation given to the first winch operating device 51.

[0095] Specifically, when the control mode is set to synchronized control mode and a first unwinding operation is applied to the first winch operating lever 51A of the first winch operating device 51, the drum operation control unit 76 controls the operation of the first winch drum DR1 and the second winch drum DR2 so that the bucket device 10 descends while maintaining the open / closed state of the bucket device 10. Also, when the control mode is set to synchronized control mode and a first winding operation is applied to the first winch operating lever 51A of the first winch operating device 51, the drum operation control unit 76 controls the operation of the first winch drum DR1 and the second winch drum DR2 so that the bucket device 10 rises while maintaining the open / closed state of the bucket device 10.

[0096] [Initial Conditions Setting] Next, the method for setting the maximum relative difference ΔLmax and the minimum relative difference ΔLmin will be explained. The condition setting unit 77 has the function of setting the maximum relative difference ΔLmax and the minimum relative difference ΔLmin, which are used when the opening / closing degree α is calculated by the opening / closing state determination unit 71.

[0097] When the condition setting unit 77 receives an ON command signal from the monitor switch 92, for example, to activate the monitor 120, it starts setting the maximum relative difference ΔLmax and the minimum relative difference ΔLmin. The condition setting unit 77 outputs a command to the screen display control unit 72 to start setting the maximum relative difference ΔLmax when the bucket device 10 is at a predetermined lifting height. Upon receiving the above command, the screen display control unit 72 displays an image on the monitor 120 as shown in the left diagram of Figure 9.

[0098] The left image in Figure 9 is an example of an image displayed on the monitor 120 when setting the maximum relative difference ΔLmax. At the bottom of the monitor 120, text instructions are displayed stating that the bucket device 10 should be opened (to the fully open state) to the extent that the first winch rope R1 and the second winch rope R2 do not slacken. Also, on the left side of the monitor 120, an image diagram shows a preferred example (right) and an unpredictable example (left) of the bucket device 10 being in the fully open state. The preferred example is when the bucket device 10 is fully open and the first winch rope R1 and the second winch rope R2 are not slack. The unpredictable example is when the bucket device 10 is fully open and the first winch rope R1 is slack. Also, the left image in Figure 9 shows the OK button 122, which is selected when the adjustment of the bucket device 10 is complete, and the BACK button 124, which returns to the previous setting, side by side.

[0099] The operator operates the first winch operating lever 51A of the first winch operating device 51 and the second winch operating lever 53A of the second winch operating device 53 in accordance with the display on the monitor 120 so that the bucket device 10 is fully open. When the operator confirms that the bucket device 10 is fully open with the first winch rope R1 and the second winch rope R2 not slackening, the operator selects the OK button 122. When the OK button 122 is selected, the condition setting unit 77 obtains the first payout amount Lm of the first winch rope R1 and the second payout amount La of the second winch rope R2 in this state and calculates the relative difference ΔL from equation (2). The condition setting unit 77 sets the calculated relative difference ΔL to the maximum relative difference ΔLmax. The condition setting unit 77 stores the set maximum relative difference ΔLmax in the storage unit 78.

[0100] Next, the condition setting unit 77 starts setting the minimum relative difference ΔLmin. The condition setting unit 77 outputs a command to the screen display control unit 72 to start setting the minimum relative difference ΔLmin when the bucket device 10 is at a predetermined lifting height. Upon receiving the above command, the screen display control unit 72 displays an image on the monitor 120 as shown in the right-hand figure of Figure 9.

[0101] The right-hand diagram in Figure 9 shows an example of an image displayed on the monitor 120 when setting the minimum relative difference ΔLmin. At the bottom of the monitor 120, text instructions are displayed indicating that the bucket device 10 should be closed (fully closed) to the extent that the first winch rope R1 and the second winch rope R2 do not slacken. On the left side of the monitor 120, an image diagram shows a preferred example (right) and an unpredictable example (left) of the bucket device 10 being fully closed. The preferred example is when the bucket device 10 is fully closed and the first winch rope R1 and the second winch rope R2 are not slack. The unpredictable example is when the bucket device 10 is fully closed and the second winch rope R2 is slack. The right-hand diagram in Figure 9 also shows the OK button 122, which is selected when the adjustment of the bucket device 10 is complete, and the BACK button 124, which returns to the previous setting.

[0102] The operator operates the first winch lever 51A and the second winch lever 53A according to the display on the monitor 120 so that the bucket device 10 is fully closed. When the operator confirms that the bucket device 10 is fully closed with the first winch rope R1 and the second winch rope R2 not slackening, the operator selects the OK button 122. When the OK button 122 is selected, the condition setting unit 77 obtains the first payout amount Lm of the first winch rope R1 and the second payout amount La of the second winch rope R2 in this state and calculates the relative difference ΔL from equation (2). The condition setting unit 77 sets the calculated relative difference ΔL as the minimum relative difference ΔLmin. The condition setting unit 77 also stores the set minimum relative difference ΔLmin in the storage unit 78.

[0103] Incidentally, the winding layers of the first winch rope R1 in the first winch drum DR1 change according to the first rotation amount nm of the first winch rope R1. In connection with this, the actual effective radius Rm of the first winch drum DR1 also changes according to the first rotation amount nm. As a result, there is an error Δrm in the effective radius Rm of the first winch drum DR1. The effective radius Rmer considering the error Δrm is shown in equation (5) below. For similar reasons, there is also an error Δra in the effective radius Ra of the second winch drum DR2. The effective radius Raer considering the error Δra is shown in equation (6) below.

[0104] Rmer = Rm + Δrm ... (5) Raer = Ra + Δra ···(6)

[0105] To reduce the effects of these errors Δrm and Δra, the maximum relative difference ΔLmax (hereinafter referred to as the maximum relative difference ΔLmaxre) and the minimum relative difference ΔLmin (hereinafter referred to as the minimum relative difference ΔLminre), taking into account the above errors Δrm and Δra, are determined as follows.

[0106] The maximum relative difference ΔLmaxre is set as the average of the maximum relative difference ΔLmax(Hhigh) set when the bucket device 10 is at its highest lift height Hhigh and the maximum relative difference ΔLmax(Hlow) set when the bucket device 10 is at its lowest lift height Hlow. Specifically, the maximum relative difference ΔLmaxre is calculated from equation (7) below. The minimum relative difference ΔLminre is set as the average of the minimum relative difference ΔLmin(Hhigh) set when the bucket device 10 is at its highest lift height Hhigh and the minimum relative difference ΔLmin(Hlow) set when the bucket device 10 is at its lowest lift height Hlow. Specifically, the minimum relative difference ΔLminre is calculated from equation (8) below.

[0107] ΔLmaxre=(ΔLmax(Hhigh)+ΔLmax(Hlow)) / 2 ···(7) ΔLminre=(ΔLmin(Hhigh)+ΔLmin(Hlow)) / 2 ···(8)

[0108] Figure 10 shows the bucket device 10 at its maximum lift height Hhigh and at its minimum lift height Hlow. The maximum lift height Hhigh is the highest position the bucket device 10 can reach. That is, the maximum lift height Hhigh is the value at which the rotation amounts nm and na of each winch drum DR1 and DR2 are minimized, and the distance between the bucket device 10 and the ground G is maximized. The minimum lift height Hlow is the lowest position the bucket device 10 can reach from the ground G. That is, the minimum lift height Hlow is the position at which the rotation amounts nm and na of each winch drum DR1 and DR2 are maximized within the range where the bucket device 10 is away from the ground G. Note that in defining the maximum lift height Hhigh and minimum lift height Hlow of the bucket device 10, the luffing member angle θ (boom angle θ) of the luffing member 104 with respect to the horizontal line is predetermined as a reference angle (for example, 45 degrees).

[0109] As described above, by using the average values ​​of the maximum relative difference ΔLmaxre and minimum relative difference ΔLminre, which are set for the maximum head Hhigh and minimum head Hlow, the effects of errors Δrm and Δra can be reduced.

[0110] When setting the maximum relative difference ΔLmax and the minimum relative difference ΔLmin, the condition setting unit 77 outputs a command to prompt the operator to move the bucket device 10 to, for example, the maximum lift height Hhigh. Specifically, the condition setting unit 77 issues a command to the screen display control unit 72 to display on the monitor 120 an instruction for the operator to move the bucket device 10 to the maximum lift height Hhigh.

[0111] The screen display control unit 72 receives the above command from the condition setting unit 77 and displays an image on the monitor 120 as shown in the left diagram of Figure 11. In the upper right corner of the monitor 120, a text instruction is displayed to raise the bucket device 10, that is, to move the bucket device 10 to the maximum lifting height Hhigh. Also, on the left side of the monitor 120, a simple diagram illustrating the above instruction is displayed. Furthermore, in the lower right corner of the monitor 120, the OK button 122, which is selected when the adjustment of the position of the bucket device 10 is complete, and the BACK button 124, which returns to the previous setting, are displayed side by side.

[0112] The operator raises the bucket device 10 to the maximum lift height Hhigh according to the display on the monitor 120, and then selects the OK button 122. After the OK button 122 is selected, the condition setting unit 77 sets the maximum relative difference ΔLmax(Hhigh) and the minimum relative difference ΔLmin(Hhigh) at the maximum lift height Hhigh.

[0113] Next, the condition setting unit 77 outputs a command to prompt the operator to move the bucket device 10 to the lowest lifting height, Hlow. Specifically, the condition setting unit 77 issues a command to the screen display control unit 72 to display on the monitor 120 an instruction for the operator to move the bucket device 10 to the lowest lifting height, Hlow.

[0114] The screen display control unit 72 receives the above command from the condition setting unit 77 and displays an image on the monitor 120 as shown in the right-hand diagram of Figure 11. In the upper right corner of the monitor 120, a text instruction is displayed to lower the bucket device 10, that is, to move the bucket device 10 to the lowest lifting height, Hlow. Also, on the left side of the monitor 120, a simplified diagram illustrating the above instruction is displayed. Furthermore, in the lower right corner of the monitor 120, the OK button 122, which is selected when the adjustment of the position of the bucket device 10 is complete, and the BACK button 124, which returns to the previous setting, are displayed side by side.

[0115] The operator lowers the bucket device 10 to the minimum lift height Hlow according to the display on the monitor 120, and then selects the OK button 122. After the OK button 122 is selected, the condition setting unit 77 sets the maximum relative difference ΔLmax(Hlow) and the minimum relative difference ΔLmin(Hlow) at the minimum lift height Hlow.

[0116] By performing the above operations, the maximum relative difference ΔLmax(Hhigh) and minimum relative difference ΔLmin(Hhigh) at the highest head height Hhigh, and the maximum relative difference ΔLmax(Hlow) and minimum relative difference ΔLmin(Hlow) at the lowest head height Hlow are obtained. Then, the condition setting unit 77 calculates the maximum relative difference ΔLmaxre and minimum relative difference ΔLminre from equations (7) and (8), taking into account the errors Δrm and Δra. When calculating the degree of opening / closing α, the use of the above maximum relative difference ΔLmaxre and minimum relative difference ΔLminre reduces the influence of the errors Δrm and Δra, improving the calculation accuracy of the degree of opening / closing α.

[0117] [Determination of the rope responsible for opening and closing] Furthermore, the opening / closing rope determination unit 79 has the function of determining whether the rope responsible for opening and closing the bucket device 10 is the first winch rope R1 (main winding rope) or the second winch rope R2 (auxiliary winding rope). Depending on how the winch ropes R1 and R2 are connected to the bucket device 10, the first winch rope R1 (main winding rope) may become the rope responsible for opening and closing the bucket device 10, or the second winch rope R2 (auxiliary winding rope) may become the rope responsible for opening and closing the bucket device 10. For example, it is possible that the rope responsible for opening and closing the bucket device 10 may be different from the rope intended by the operator. Therefore, the opening / closing rope determination unit 79 determines the rope responsible for opening and closing the bucket device 10 in accordance with the settings of the maximum relative difference ΔLmax and minimum relative difference ΔLmin described above.

[0118] The opening / closing rope determination unit 79 calculates the first change amount ΔLm and the second change amount ΔLa without changing the lifting height of the bucket device 10. Specifically, the opening / closing rope determination unit 79 calculates, for example, the first change amount ΔLm of the first payout amount Lm of the first winch rope R1 and the second change amount ΔLa of the second payout amount La of the second winch rope R2 when the bucket device 10 is at its lowest lifting height Hlow. The first change amount ΔLm is calculated from the following equation (9). In equation (9), Lmopn is the first payout amount Lm when the bucket device 10 is in the fully open state, and Lmcls is the first payout amount Lm when the bucket device 10 is in the fully closed state. The second change amount ΔLa is calculated from the following equation (10). In equation (10), Laopn is the second payout amount La when the bucket device 10 is fully open, and Lacls is the second payout amount La when the bucket device 10 is fully closed. From equation (9), the first change ΔLm is the difference between the first payout amount Lmopn of the first winch rope R1 when the bucket device 10 is fully open and the first payout amount Lmcls of the first winch rope R1 when the bucket device 10 is fully closed. Also, from equation (10), the second change ΔLa is the difference between the second payout amount Laopn of the second winch rope R2 when the bucket device 10 is fully open and the second payout amount Lacls when the bucket device 10 is fully closed.

[0119] ΔLm = Lmopn - Lmcls ···(9) ΔLa = Laopn - Lacls ···(10)

[0120] The opening / closing rope determination unit 79 calculates the first change amount ΔLm and the second change amount ΔLa, and then determines whether the calculated first change amount ΔLm is greater than the second change amount ΔLa. If the first change amount ΔLm is greater than the second change amount ΔLa, the opening / closing rope determination unit 79 determines that the first winch rope R1 is responsible for opening and closing the bucket device 10, and the second winch rope R2 is responsible for supporting the bucket device 10. On the other hand, if the first change amount ΔLm is less than the second change amount ΔLa, the unit determines that the second winch rope R2 is responsible for opening and closing, and the first winch rope R1 is responsible for supporting the bucket device 10.

[0121] Figure 12 is a flowchart illustrating the control operations performed by the opening / closing rope determination unit 79 when determining the rope responsible for opening and closing the bucket device 10. The flowchart in Figure 12 is performed during the initial setup, for example, when the bucket device 10 is at its lowest lifting height, Hlow.

[0122] First, the opening / closing rope determination unit 79 calculates the change in the first payout amount Lm of the first winch rope R1, ΔLm, from the first payout amount Lmopn of the first winch rope R1 when the bucket device 10 is fully open, and the first payout amount Lmcls of the first winch rope R1 when the bucket device 10 is fully closed (step S10). Next, the opening / closing rope determination unit 79 calculates the change in the second payout amount La of the second winch rope R2, ΔLa, from the second payout amount Laopn of the second winch rope R2 when the bucket device 10 is fully open, and the second payout amount Lacls of the second winch rope R2 when the bucket device 10 is fully closed (step S20). Next, the opening / closing rope determination unit 79 determines whether the change in ΔLm calculated in step S10 is greater than the change in ΔLa calculated in step S20 (step S30). If the change amount ΔLm is greater than the change amount ΔLa (Yes in step S30), the opening / closing rope determination unit 79 determines that the first winch rope R1 is the rope responsible for opening and closing the bucket device 10 (step S40). On the other hand, if the change amount ΔLm is less than the change amount ΔLa (No in step S30), the opening / closing rope determination unit 79 determines that the second winch rope R2 is the rope responsible for opening and closing the bucket device 10 (step S50).

[0123] Based on the flowchart in Figure 12, if, for example, the first winch rope R1 is determined to be the rope responsible for opening and closing the bucket device 10, the opening / closing rope determination unit 79 issues a command to the screen display control unit 72 to display an image as shown in Figure 13 on the monitor 120 in order to confirm whether this determination is what the operator intended. The screen display control unit 72 displays an image as shown in Figure 13 on the monitor 120 in accordance with the above command. If the rope responsible for opening and closing the bucket device 10 is determined to be the first winch rope R1, the connection destination of the rope responsible for opening and closing will be displayed as "main winding (first winch rope R1)" as shown in Figure 13. If the rope responsible for opening and closing the bucket device 10 is determined to be the second winch rope R2, the connection destination of the rope responsible for opening and closing will be displayed as "auxiliary winding (second winch rope R2)".

[0124] If the display on monitor 120 matches the operator's intention, the operator selects the OK button 122. On the other hand, if, for example, the display on monitor 120 does not match the operator's intention, the operator selects the BACK button 124 and reconfirms the rope connection destination. This operation prevents the operator from using the wrong rope to open and close the bucket device 10.

[0125] Figure 14 is a flowchart illustrating the control operations of the controller 70, which are performed when the maximum relative difference ΔLmax and minimum relative difference ΔLmin are set, and when the rope responsible for opening and closing the bucket device 10 is determined. In Figure 14, the areas enclosed by dashed lines correspond to the control operations performed when the bucket device 10 is at its maximum lifting height Hhigh, and the areas enclosed by dashed lines correspond to the control operations performed when the bucket device 10 is at its minimum lifting height Hlow.

[0126] To perform the initial setup, first, the controller 70 displays the left diagram of Figure 11 on the monitor 120 in order to move the bucket device 10 to the maximum lifting height Hhigh (step S100). The operator moves the bucket device 10 to the maximum lifting height Hhigh according to the display on the monitor 120. Next, the controller 70 determines whether the OK button 122 or the BACK button 124 displayed in the left diagram of Figure 11 was selected. If the BACK button 124 is selected (NO in step S110), the controller 70 completes the initial setup and then runs the initial setup again from the beginning. If the OK button 122 is selected in step S110 (YES in S110), the controller 70 displays the left diagram of Figure 9 on the monitor 120 (step S120). The operator fully opens the bucket device 10 according to the display on the monitor 120. Next, the controller 70 determines which of the OK button 122 and the BACK button 124 displayed on the monitor 120 has been selected (step S130). If the BACK button 124 is selected (NO in step S130), the controller 70 returns to step S100. If the OK button 122 is selected (YES in S130), the controller 70 stores the maximum relative difference ΔLmax(Hhigh) calculated when the bucket device 10 is in the fully open state in the storage unit 78 (step S140). Next, the controller 70 displays the right diagram of Figure 9 on the monitor 120 (step S150). The operator closes the bucket device 10 in the fully closed state according to the display on the monitor 120. Next, the controller 70 determines which of the OK button 122 and the BACK button 124 displayed on the monitor 120 has been selected (step S160). If the BACK button 124 is selected (NO in step S160), the controller 70 returns to S120. If the OK button 122 is selected (YES in step S160), the controller 70 causes the storage unit 78 to store the minimum relative difference ΔLmin(Hhigh) calculated when the bucket device 10 is in a fully closed state (step S170).

[0127] Next, in order to move the bucket device 10 to the lowest lift height (Hlow), the controller 70 displays the right diagram of Figure 11 on the monitor 120 (step S180). The operator moves the bucket device 10 to the lowest lift height (Hlow) according to the display on the monitor 120. Next, the controller 70 determines which of the OK button 122 and BACK button 124 displayed on the monitor 120 was selected (step S190). If the BACK button 124 was selected (NO in S190), the controller 70 returns to step S150. If the OK button 122 was selected (YES in step S190), the controller 70 displays the left diagram of Figure 9 on the monitor 120 (step S200). The operator fully opens the bucket device 10 according to the display on the monitor 120. Next, the controller 70 determines which of the OK button 122 and BACK button 124 displayed on the monitor 120 was selected (step S210). If the BACK button 124 is selected (NO in step S210), the controller 70 returns to step S180. If the OK button 122 is selected (YES in step S210), the controller 70 stores the maximum relative difference ΔLmax(Hlow) calculated when the bucket device 10 is fully open in the storage unit 78. Furthermore, the controller 70 stores the first payout amount Lmopn of the first winch rope R1 and the second payout amount Laopn of the second winch rope R2 in the storage unit 78 when the bucket device 10 is fully open. Next, the controller 70 displays the right diagram of Figure 9 on the monitor 120 (step S230). The operator closes the bucket device 10 according to the display on the monitor 120. Next, the controller 70 determines which of the OK button 122 and BACK button 124 displayed on the monitor 120 was selected (step S240). If the BACK button 124 is selected (NO in step S240), the controller 70 returns to step S200. If the OK button 122 is selected (YES in step S240), the controller 70 stores the minimum relative difference ΔLmin(Hlow) calculated when the bucket device 10 is in a fully closed state in the storage unit 78 (step S250).Furthermore, the controller 70 stores the first payout amount Lmcls of the first winch rope R1 and the second payout amount Lacls of the second winch rope R2 in the storage unit 78 when the bucket is fully closed (step S250). Next, the controller 70 calculates the final maximum relative difference ΔLmaxre and minimum relative difference ΔLminre using equations (7) and (8) (step S260). Then, the controller 70 determines which rope is responsible for opening and closing the bucket device 10 according to the flowchart in Figure 12 described above, and then completes the initial setup.

[0128] [Second Embodiment] In the first embodiment described above, the degree of opening / closing α of the bucket device 10 was calculated using the relative difference ΔL (=Lm-La) between the first payout amount Lm and the second payout amount La. Alternatively, the opening / closing state determination unit 71 may calculate the degree of opening / closing α using the difference in lifting values ​​ΔLF (=ΔLFm-ΔLFa), which is the difference between the lifting value of the first winch rope R1 (first lifting value LFm) and the lifting value of the second winch rope R2 (second lifting value LFa).

[0129] The lifting height value LF referred to here is different from the lifting height of the bucket device 10 (height from the ground G), and corresponds to the change in lifting height based on a specific state. For example, a specific state may be set to a state where the first winch drum DR1 is at 0 rotations, the second winch drum DR2 is at 0 rotations, and the luffing member angle θ (boom angle θ) of the luffing member 104 with respect to the horizontal line is 45 degrees. The state of "first winch drum DR1 at 0 rotations" is the state in which the first winch rope R1 has been fully extended from the first winch drum DR1. The state of "second winch drum DR2 at 0 rotations" is the state in which the second winch rope R2 has been fully extended from the second winch drum DR2. When the lifting height value of the first winch rope R1 in this specific state is taken as the reference (zero), the first lifting height value LFm is the change in lifting height from that reference. Similarly, when the lifting height of the second winch rope R2 in the aforementioned specific state is taken as the baseline (zero), the second lifting height value LFa is the amount of change in lifting height from that baseline.

[0130] The controller 70 can calculate the first lifting height value LFm of the first winch rope R1 based on the amount of rotation nm of the first winch drum DR1 detected by the first rotation sensor 81 and the luffing member angle θ detected by the luffing member angle detector 83 (see Figure 10). Similarly, the controller 70 can calculate the second lifting height value LFa of the second winch rope R2 based on the amount of rotation na of the second winch drum DR2 detected by the second rotation sensor 82 and the luffing member angle θ. Specifically, it is as follows.

[0131] The first lifting height value LFm of the first winch rope R1 changes not only according to the amount of the first winch rope R1 unfurled from the first winch drum DR1, but also according to the luffing member angle θ of the luffing member 104. Similarly, the second lifting height value LFa of the second winch rope R2 changes not only according to the amount of the second winch rope R2 unfurled from the second winch drum DR2, but also according to the luffing member angle θ of the luffing member 104.

[0132] The controller 70 may pre-store specification data including the length of the luffing member 104, data relating to the relative position of the first winch drum DR1 with respect to a specific part of the luffing member 104 (for example, the base end of the luffing member 104), and data relating to the relative position of the second winch drum DR2 with respect to the said specific part of the luffing member 104. In this case, the controller 70 can calculate a first distance and a second distance that change according to the luffing member angle θ from the geometric positional relationship of the luffing member 104, the first winch drum DR1, and the second winch drum DR2. The first distance is the distance from the first winch drum DR1 to a predetermined first part of the luffing member 104 (for example, the upper end of the luffing member 104). The second distance is the distance from the second winch drum DR2 to a predetermined second part of the luffing member 104 (for example, the upper end of the luffing member 104). Furthermore, the controller 70 may pre-store a relational expression representing the relationship between the luffing member angle θ and the first distance, and a relational expression representing the relationship between the luffing member angle θ and the second distance. In this case, the controller 70 may calculate the first distance and the second distance using the luffing member angle θ detected by the luffing member angle detector 83 and the two relational expressions described above.

[0133] The controller 70 uses information such as specification data including the length of the luffing member 104, data regarding the relative position of the first winch drum DR1 with respect to the specific part of the luffing member 104, and data regarding the relative position of the second winch drum DR2 with respect to the specific part of the luffing member 104, as well as detection results input to the controller 70 from the rotation sensors 81 and 82, and the luffing member angle θ of the luffing member 104 input to the controller 70 from the luffing member angle detector 83, to calculate the first lifting height value LFm of the first winch rope R1 and the second lifting height value LFa of the second winch rope R2, respectively.

[0134] Specifically, for example, the controller 70 may calculate the first lifting height value LFm of the first winch rope R1 based on the change in the first distance ΔL1 for the specific state, the change in the height position of the upper end of the luffing member 104 ΔH1 for the specific state, and the change in the amount of the first winch rope R1 extended ΔR1 for the specific state. The controller 70 may also calculate the first lifting height value LFm of the first winch rope R1 using, for example, the following equation (11).

[0135] First head value LFm = -(ΔL1 + ΔH1 + ΔR1) ... (11)

[0136] Similarly, the controller 70 may calculate the second lifting height value LFab of the second winch rope R2 based on the change in the second distance ΔL2 for the specific state, the change in the height position of the upper end of the luffing member 104 ΔH2 for the specific state, and the change in the amount of the second winch rope R2 extended ΔR2 for the specific state. The controller 70 may calculate the second lifting height value LFab of the second winch rope R2 using, for example, the following equation (12).

[0137] Second head value LFab = -(ΔL2 + ΔH2 + ΔR2) ... (12)

[0138] In the second embodiment, the opening / closing state determination unit 73 calculates the degree of opening / closing α using the following equation (13). In equation (13), the maximum lift value difference ΔLFmax and the minimum lift value difference ΔLFmin are preset values. The maximum lift value difference ΔLFmax is the difference in lift values ​​between the first lift value LFm of the first winch rope R1 and the second lift value LFa of the second winch rope R2 when the bucket device 10 is in the fully open state, and is preset in the same way as the maximum relative difference ΔLmax described above. The minimum lift value difference ΔLFmin is the difference in lift values ​​between the first lift value LFm of the first winch rope R1 and the second lift value LFa of the second winch rope R2 when the bucket device 10 is in the fully closed state, and is preset in the same way as the minimum relative difference ΔLmin described above. The opening / closing state determination unit 73 calculates the degree of opening / closing α of the bucket device 10 by applying the lifting height difference ΔLF, the maximum lifting height difference ΔLFmax, and the minimum lifting height difference ΔLFmin, which are calculated as needed, to equation (13). The maximum lifting height difference ΔLFmax corresponds to the first lifting height reference value of this disclosure, and the minimum lifting height difference ΔLFmin corresponds to the second lifting height reference value of this disclosure.

[0139] α=(ΔLF-ΔLFmin) / (ΔLFmax-ΔLFmin)×100 (13)

[0140] Furthermore, in order to improve the calculation accuracy of the degree of opening α, the maximum head difference ΔLFmax may be the average of the maximum head difference ΔLFmax(Hhigh) set when the head of the bucket device 10 is at the highest head height Hhigh and the minimum head difference ΔLFmin(Hlow) set when the head of the bucket device 10 is at the lowest head height Hlow. Similarly, the minimum head difference ΔLFmin may be the average of the minimum head difference ΔLFmin(Hhigh) set when the head of the bucket device 10 is at the highest head height Hhigh and the minimum head difference ΔLFmin(Hlow) set when the head of the bucket device 10 is at the lowest head height Hlow. This further improves the calculation accuracy of the degree of opening α.

[0141] Furthermore, the opening / closing state determination unit 73 may determine whether the bucket device 10 is in an over-open state or an over-closed state based on the lifting height difference ΔLF, the maximum lifting height difference ΔLFmax, and the minimum lifting height difference ΔLFmin. Specifically, the opening / closing state determination unit 73 determines that the bucket device 10 is in an over-open state if the lifting height difference ΔLF is greater than the maximum lifting height difference ΔLFmax, and determines that the bucket device 10 is in an over-closed state if the lifting height difference ΔLF is less than the minimum lifting height difference ΔLFmin.

[0142] Alternatively, the opening / closing rope determination unit 79 may determine which of the first winch rope R1 and the second winch rope R2 is responsible for opening and closing the bucket device 10, using the first lifting height value LFm of the first winch rope R1 and the second lifting height value LFa of the second winch rope R2.

[0143] Specifically, the opening / closing rope determination unit 79 calculates a first lift change amount ΔLFm, which is the difference (=LFmopn-LFmcls) between the first lift value LFmopn of the first winch rope R1 when the bucket device 10 is in a fully open state and the first lift value LFmcls of the first winch rope R1 when the bucket device 10 is in a fully closed state. Furthermore, the opening / closing rope determination unit 79 calculates a second lift change amount ΔLFa, which is the difference (=LFaopn-LFacls) between the second lift value LFabapn of the second winch rope R2 when the bucket device 10 is in a fully open state and the second lift value LFacls of the second winch rope R2 when the bucket device 10 is in a fully closed state. If the calculated first lift change amount ΔLFm is greater than the second lift change amount ΔLFa, the opening / closing rope determination unit 79 determines that the first winch rope R1 is the rope responsible for opening and closing the bucket device 10. Furthermore, the opening / closing rope determination unit 79 determines that the second winch rope R2 is responsible for opening and closing the bucket device 10 if the calculated first lifting height change amount ΔLFm is smaller than the second lifting height change amount ΔLFa. In this way, the opening / closing degree α and the determination of which rope is responsible for opening and closing the bucket device 10 can also be performed using the first lifting height value LFm of the first winch rope R1 and the second lifting height value LFa of the second winch rope R2, and the same operation and effect as in the first embodiment can be obtained. That is, the opening / closing degree α calculated based on the lifting height value LF is displayed on the monitor 120, and the opening / closing degree α of the bucket device 10 is notified to the operator via the monitor 120. As a result, even when it is difficult to visually inspect the bucket device 10, the status of the bucket device 10 can be grasped.

[0144] [Differentiation] In the above embodiment, the degree of opening / closing α was displayed as a gauge (bar graph), but this disclosure is not limited to a gauge. For example, the degree of opening / closing α may be displayed as a pie chart, or as a meter. In other words, any display that allows the operator to grasp the degree of opening / closing α visually is acceptable. Furthermore, it is not necessarily required to display the degree of opening / closing α using a diagram such as a gauge; the degree of opening / closing α may be displayed only as a numerical value on the monitor 120.

[0145] In the above embodiment, the bucket device 10 is first moved to the highest lifting height Hhigh, and the maximum relative difference ΔLmax(Hhigh) and minimum relative difference ΔLmin(Hhigh) are calculated. Then, the bucket device 10 is moved to the lowest lifting height Hlow, and the maximum relative difference ΔLmax(Hlow) and minimum relative difference ΔLmin(Hlow) are calculated. However, this order may be reversed. That is, in the flowchart of Figure 14, the controller 70 may first execute the control operations from step S180 to step S250, and then execute the control operations from step S100 to step S170.

[0146] In the above embodiment, the rope responsible for opening and closing the bucket device 10 was determined from the change in the first payout amount Lm of the first winch rope R1 and the change in the second payout amount La of the second winch rope R2 when the bucket device 10 is at its lowest lifting height Hlow (ΔLm). However, this disclosure is not limited thereto. For example, the rope responsible for opening and closing the bucket device 10 may be determined from the change in the first payout amount Lm of the first winch rope R1 and the change in the second payout amount La of the second winch rope R2 when the bucket device 10 is at its highest lifting height Hhigh (ΔLm). Alternatively, the rope responsible for opening and closing the bucket device 10 may be determined at a predetermined position different from both the highest lifting height Hhigh and the lowest lifting height Hlow.

[0147] In the above embodiment, the final maximum relative difference ΔLmax and minimum relative difference ΔLmin were determined from the average values ​​of the maximum relative difference ΔLmax and minimum relative difference ΔLmin when the bucket device 10 is at its highest lift height Hhigh and when the bucket device 10 is at its lowest lift height Hlow, but the disclosure is not limited thereto. For example, the maximum relative difference ΔLmax(Hhigh) and minimum relative difference ΔLmin(Hhigh) may be set based on the bucket device 10 being at a predetermined lift height. Similarly, the maximum lift value difference ΔLFmax and minimum lift value difference ΔLFmin may also be set based on the bucket device 10 being at a predetermined lift height.

[0148] In the above embodiment, the degree of opening / closing α was displayed on the monitor 120 to inform the operator of the open / closed state of the bucket device 10. However, other means may be used as long as they can inform the operator of the open / closed state. For example, the degree of opening / closing α may be announced audibly from a sound-generating device such as a speaker. Alternatively, both the monitor 120 and the sound-generating device may be used to inform the operator of the open / closed state of the bucket device 10.

[0149] In the above embodiment, the initial setup was initiated when the monitor switch 92 for activating the monitor 120 was selected, but this disclosure is not limited thereto. For example, an initial setup switch for initiating the initial setup may be set, and the initial setup may be initiated when the initial setup switch is selected.

[0150] In the above embodiment, the bucket device 10 was mounted on a crane 100 as a construction machine, but this disclosure is not limited to cranes. This disclosure applies to any construction machine that includes a bucket device that is openable and closable and raised and lowered in accordance with the rotation of the first winch drum and the rotation of the second winch drum, and which includes a first winch drum for paying out and winding up a first winch rope and a second winch drum for paying out and winding up a second winch rope.

[0151] In the above embodiment, the storage unit 78 was built into the controller 70, but the storage unit 78 may be located separately from the controller 70.

[0152] In the above embodiment, the control mode of the bucket device 10 was configured to be switchable between assist mode, non-assist mode, synchronized control mode, and non-synchronized control mode. However, this disclosure is not limited to embodiments that include the above control modes. That is, this disclosure is also applicable to conventional cranes that do not have the above control modes.

[0153] In the above embodiment, the bucket control device is provided on the crane 100, but the bucket control device in this disclosure does not necessarily have to be provided on a construction machine such as the crane 100, and may be located at a location away from the construction machine. In this case, the bucket control device is configured to be able to send and receive information between the bucket control device and the construction machine via a network such as the internet or a mobile phone network.

[0154] In the above embodiment, the luffing member 104 shown in Figure 1 is a boom having a lattice structure (lattice boom), but the luffing member may include a boom having a lattice structure and a jib having a lattice structure, or it may be an extendable boom (telescopic boom). The construction machine may be placed on the ground, on a structure, or on a ship. In any of these cases, the lower body of the construction machine may have a crawler running device as shown in Figure 1, a running device including tires, or it may be composed of a structure such as a support platform that cannot move on its own. [Explanation of Symbols]

[0155] 10: Bucket device 70: Controller 81: First rotation sensor (first detector) 82: Second rotation sensor (second detector) 100: Crane (construction machinery) DR1: First winch drum DR2: Second winch drum R1: First winch rope R2: Second winch rope

Claims

1. A bucket control device for a construction machine, comprising: a first winch drum for paying out and reeling in a first winch rope; a second winch drum for paying out and reeling in a second winch rope; and a bucket device connected to the first and second winch ropes, which is openable and closable and raised and lowered in accordance with the rotation of the first and second winch drums, A bucket control device comprising a controller that determines the open / closed state of the bucket device and notifies the operator of the determined open / closed state of the bucket device.

2. In the bucket control device according to claim 1, The aforementioned construction machine, A first detector for detecting the first payout amount, which is the amount of the first winch rope that is paid out, or the first lifting height value of the first winch rope, The system includes a second detector for detecting the second payout amount, which is the amount of the second winch rope that is paid out, or the second lifting height value of the second winch rope, The controller calculates the degree of opening or closing of the bucket device based on the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope, a first reference value which is the difference when the bucket device is in a fully open state, and a second reference value which is the difference when the bucket device is in a fully closed state, or The controller is a bucket control device that calculates the degree of opening and closing of the bucket device based on the difference in lifting values ​​between the first lifting value of the first winch rope and the second lifting value of the second winch rope, a first lifting reference value which is the difference in lifting values ​​when the bucket device is in the fully open state, and a second lifting reference value which is the difference in lifting values ​​when the bucket device is in the fully closed state.

3. In the bucket control device according to claim 2, The controller presets the first reference value and the second reference value, or the first head reference value and the second head reference value. The aforementioned controller, The bucket device calculates the first reference value from the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in the fully open state. The bucket device calculates the second reference value from the difference between the first payout amount of the first winch rope and the second payout amount of the second winch rope when the bucket device is in the fully closed state. The bucket device calculates a first lifting reference value from the difference in lifting values ​​between the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in the fully open state. A bucket control device that calculates a second lifting reference value from the difference in lifting values ​​between the first lifting value of the first winch rope and the second lifting value of the second winch rope when the bucket device is in the fully closed state.

4. In the bucket control device according to claim 3, The first reference value is set as the average of the first reference value set when the lifting height of the bucket device is at a predetermined maximum lifting height and the first reference value set when the lifting height of the bucket device is at a predetermined minimum lifting height. The second reference value is set as the average of the second reference value set when the lifting height of the bucket device is at the maximum lifting height and the second reference value set when the lifting height of the bucket device is at the minimum lifting height. The first lifting height reference value is set as the average of the first lifting height reference value set when the lifting height of the bucket device is at the maximum lifting height and the first lifting height reference value set when the lifting height of the bucket device is at the minimum lifting height. A bucket control device in which the second lifting reference value is set to the average value of the second lifting reference value set when the lifting height of the bucket device is at the maximum lifting height and the second lifting reference value set when the lifting height of the bucket device is at the minimum lifting height.

5. In the bucket control device according to any one of claims 2 to 4, The aforementioned controller, The first change is the difference between the first payout amount of the first winch rope when the bucket device is in the fully open state and the first payout amount of the first winch rope when the bucket device is in the fully closed state, The second change is calculated as the difference between the second payout amount of the second winch rope when the bucket device is in the fully open state and the second payout amount of the second winch rope when the bucket device is in the fully closed state. A bucket control device that determines that the first winch rope is responsible for opening and closing the bucket device when the first change is greater than the second change, and determines that the second winch rope is responsible for opening and closing the bucket device when the first change is less than the second change.

6. In the bucket control device according to any one of claims 2 to 4, The aforementioned controller, The first lifting height change is the difference between the first lifting height of the first winch rope when the bucket device is in the fully open state and the first lifting height of the first winch rope when the bucket device is in the fully closed state, The second lifting height change is calculated as the difference between the second lifting height of the second winch rope when the bucket device is in the fully open state and the second lifting height of the second winch rope when the bucket device is in the fully closed state. A bucket control device that determines that the first winch rope is responsible for opening and closing the bucket device when the first change in lifting height is greater than the second change in lifting height, and determines that the second winch rope is responsible for opening and closing the bucket device when the first change in lifting height is less than the second change in lifting height.

7. The first winch drum and, The aforementioned second winch drum, The aforementioned bucket device, A construction machine comprising a bucket control device according to any one of claims 1 to 4.

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