Synchronization control device, construction machinery, and synchronization control method

Abstract

The present invention provides a technology that enables raising a bucket device while minimizing the deviation in a physical quantity correlated with the payout amount of two winch ropes connected to the bucket device, and raising the bucket device while minimizing the deviation in the tension acting on the two winch ropes. [Solution] The synchronization control device includes a controller that can select between power synchronization control to reduce the deviation between a physical quantity correlated with the amount of the first winch rope unwound and a physical quantity correlated with the amount of the second winch rope unwound when raising the bucket device, and tension synchronization control to reduce the tension deviation, which is the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope when raising the bucket device.

Description

[Technical Field]

[0001] This disclosure relates to the technology of a construction machine equipped with a bucket device. [Background technology]

[0002] Conventionally, construction machines equipped with a bucket device are known (for example, Patent Documents 1-3). The construction machine comprises a first winch rope and a second winch rope connected to the bucket device, a first winch drum for paying out and reeling in the first winch rope, and a second winch drum for paying out and reeling in the second winch rope. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-327497 [Patent Document 2] Japanese Patent Publication No. 2023-23811 [Patent Document 3] Japanese Patent Publication No. 2023-23812 [Overview of the project] [Problems that the invention aims to solve]

[0004] When the bucket device is raised, there are two cases in which it is desirable to prioritize minimizing the deviation between a physical quantity correlated with the amount of the first winch rope paid out and a physical quantity correlated with the amount of the second winch rope paid out, and cases in which it is desirable to prioritize minimizing the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope. [Means for solving the problem]

[0005] The present disclosure aims to provide a technology that can raise a bucket device while reducing the deviation of a physical quantity correlated with the payout amount of two winch ropes connected to the bucket device, and raise the bucket device while reducing the deviation of the tension acting on the two winch ropes.

[0006] The synchronization control device according to the first embodiment is a control device for a construction machine. The construction machine comprises a machine body, a luffing member that can be raised and lowered relative to the machine body, a first winch drum for paying out and reeling in a first winch rope hanging from the luffing member, a second winch drum for paying out and reeling in a second winch rope hanging from the luffing member, and a bucket device to which the first winch rope and the second winch rope are connected and which can be raised and lowered in accordance with the operation of the first winch drum and the operation of the second winch drum. The synchronization control device includes a controller that can select either power synchronization control for reducing the deviation between a physical quantity correlated with the amount of the first winch rope unwound and a physical quantity correlated with the amount of the second winch rope unwound when raising the bucket device, or tension synchronization control for reducing the tension deviation, which is the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope when raising the bucket device.

[0007] In the first embodiment, when the controller selects and executes the power synchronization control, the deviation between the physical quantity correlated with the payout amount of the first winch rope and the physical quantity correlated with the payout amount of the second winch rope becomes smaller when the bucket device is raised. On the other hand, when the controller selects and executes the tension synchronization control, the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope becomes smaller when the bucket device is raised. Therefore, in this first embodiment, it is possible to raise the bucket device while reducing the deviation of the physical quantities correlated with the payout amounts of the two winch ropes connected to the bucket device, and to raise the bucket device while reducing the deviation of the tension acting on the two winch ropes.

[0008] A synchronization control device according to a second embodiment preferably comprises the following additional configurations in addition to that of a synchronization control device according to a first embodiment. That is, in the second embodiment, the controller preferably performs feedback control in the power synchronization control based on the deviation between a physical quantity correlated with the payout amount of the first winch rope and a physical quantity correlated with the payout amount of the second winch rope. This makes it possible to effectively reduce the deviation between the physical quantity correlated with the payout amount of the first winch rope and the physical quantity correlated with the payout amount of the second winch rope when the bucket device is raised in the power synchronization control.

[0009] A synchronization control device according to a third embodiment preferably further comprises the following configuration in addition to the synchronization control device according to the first or second embodiment. That is, in the third embodiment, the construction machine includes a first winch motor which is a variable displacement hydraulic motor for operating the first winch drum, a second winch motor which is a variable displacement hydraulic motor for operating the second winch drum, a first constant horsepower control valve for adjusting the capacity of the first winch motor in accordance with the load acting on the first winch motor to keep the output of the first winch motor constant, a second constant horsepower control valve for adjusting the capacity of the second winch motor in accordance with the load acting on the second winch motor to keep the output of the second winch motor constant, and the winding of the first winch drum The controller further comprises a first winding proportional valve that outputs a pilot pressure for controlling the winding operation, a second winding proportional valve that outputs a pilot pressure for controlling the winding operation of the second winch drum, a first winch operating device that receives a first winding operation for winding the first winch rope onto the first winch drum, and a second winch operating device that receives a second winding operation for winding the second winch rope onto the second winch drum, wherein the controller preferably inputs the same current command value to the first winding proportional valve and the second winding proportional valve in the tension synchronization control.

[0010] In this third embodiment, the controller does not perform feedback control based on the deviation between a physical quantity correlated with the payout amount of the first winch rope and a physical quantity correlated with the payout amount of the second winch rope in the tension synchronization control, but instead inputs the same current command value to the first winding proportional valve and the second winding proportional valve. As a result, the first winch drum and the second winch drum perform a winding operation to wind up the first winch rope and the second winch rope, respectively, and the bucket device rises. When the bucket device rises, the tension acting on the first winch rope and the tension acting on the second winch rope are mechanically adjusted by the first constant horsepower control valve and the second constant horsepower control valve, respectively. Therefore, the controller can raise the bucket device while reducing the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope by performing the tension synchronization control, which involves inputting the same current command value to the first and second winch proportional valves.

[0011] The synchronization control device according to the fourth embodiment preferably further comprises the following configuration in addition to the synchronization control device according to any one of the first to third embodiments. That is, in the fourth embodiment, the construction machine further comprises an input device capable of receiving input from an operator, and the controller preferably selects either the power synchronization control or the tension synchronization control based on the input received by the input device and executes the selected control.

[0012] The construction machine according to the fifth embodiment comprises the machine body, the luffing member, the first winch drum, the second winch drum, the bucket device, and a synchronization control device according to any one of the first to fourth embodiments.

[0013] The synchronization control method according to the sixth aspect is a control method for construction machinery. The construction machinery includes a machine body, a lifting member that can be lifted with respect to the machine body, a first winch drum that pays out and winds up a first winch rope hanging down from the lifting member, a second winch drum that pays out and winds up a second winch rope hanging down from the lifting member, a bucket device that is connected to the first winch rope and the second winch rope and can be lifted and lowered according to the operations of the first winch drum and the second winch drum. The synchronization control method includes the controller selecting either power synchronization control for reducing the deviation between a physical quantity correlated with the payout amount of the first winch rope and a physical quantity correlated with the payout amount of the second winch rope when lifting the bucket device, or tension synchronization control for reducing the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope when lifting the bucket device.

Effect of the Invention

[0014] As described above, according to the present disclosure, there is provided a technique capable of lifting the bucket device while reducing the deviation of the physical quantity correlated with the payout amount of the two winch ropes connected to the bucket device, and lifting the bucket device while reducing the deviation of the tension acting on the two winch ropes.

Brief Description of the Drawings

[0015] [Figure 1] It is a side view showing a crane equipped with a synchronization control device according to an embodiment of the present disclosure. [Figure 2] It is a block diagram showing a first winch, a second winch, and a bucket device in the crane and main components related thereto. [Figure 3] It is a diagram showing a portion related to the first winch and the second winch among the hydraulic circuits provided in the crane. [Figure 4]This is a diagram illustrating the opening and closing operation of the bucket device provided by the crane. [Figure 5] This is an example of a map showing the relationship between the amount of winding operation performed by the winch operating device and the target pilot pressure. [Figure 6] This is an example of a map showing the relationship between the target pilot pressure and the commanded current value. [Figure 7] This figure shows an example of an input device that can receive input from an operator. [Figure 8] This flowchart shows an example of the calculation process performed by the controller of the aforementioned synchronization control device. [Figure 9] This is a block diagram showing the controller and related main components of a tuning control device according to a modified embodiment of the above-described embodiment. [Figure 10] This flowchart shows an example of the calculation process performed by the controller according to the modified example described above. [Figure 11] This is a circuit diagram showing an example of a constant horsepower control valve. [Modes for carrying out the invention]

[0016] Embodiments of this disclosure will be described with reference to the drawings.

[0017] Figure 1 shows a crane 100, which is a construction machine according to this 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 plurality of winches arranged on the upper slewing body 102, and a bucket device 10.

[0018] The lower body 101 is a self-propelled lower traveling body equipped with a traveling device such as a crawler traveling device. However, the lower body in this disclosure may be a structure such as a support base that rotatably supports the upper rotating body 102 and is not self-propelled.

[0019] The upper slewing body 102 comprises a slewing frame 103 rotatably mounted on the lower body 101, a cabin 114 supported at the front of the slewing frame 103, and a counterweight 115 supported at the rear of the slewing frame 103. The lower body 101 and the upper slewing body 102 are examples of the machine body in this disclosure. However, if the lower body is the structure such as the support base, the machine body in this disclosure may consist of the structure and the upper slewing body.

[0020] The luffing member 104 includes a boom that is luffably supported on the slewing frame 103. However, the luffing member in this disclosure may also include a boom and a jib (not shown) that is rotatably supported on the upper end of the boom. The luffing member 104 includes a luffing member body 104A and a plurality of sheaves. The luffing member body 104A is the portion of the upper slewing body 102 that is positioned to protrude from the slewing frame 103 and constitutes the majority of the luffing member 104. In the specific example shown in Figure 1, the luffing member body 104A is composed of a boom having a lattice structure. The plurality of sheaves include a first point sheave 105, a second point sheave 106, a first idler sheave 112, and a second idler sheave 113, which are attached to the upper end of the luffing member body 104A as shown in Figure 1.

[0021] 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 upper end 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 R3 is wrapped around the lower spreader 110 and the upper spreader 109.

[0022] The aforementioned plurality of winches include a first winch WC1, a second winch WC2, and a luffing winch WC3. The first winch WC1 has a first winch drum DR1 for paying out and winding in the first winch rope R1 (wire rope). The second winch WC2 has a second winch drum DR2 for paying out and winding in the second winch rope R2 (wire rope). The luffing winch WC3 has a luffing winch drum DR3 for paying out and winding in the luffing rope R3 (wire rope).

[0023] The first winch WC1 and the second winch WC2 open and close the bucket device 10 and raise and lower it.

[0024] The luffing rope R3 extends from the luffing winch drum DR3 to the lower spreader 110 and is wrapped around the lower spreader 110 and the upper spreader 109. 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 R3. As this distance decreases or increases, the luffing member 104 rumbles. In other words, the luffing winch WC3 can make the luffing member 104 rumble relative to the upper slewing body 102 by winding in or unwinding the luffing rope R3.

[0025] Figure 2 is a block diagram showing the first winch WC1, the second winch WC2, and the bucket device 10 of the crane 100, and the main components related thereto. Figure 3 is a diagram showing the parts of the hydraulic circuit of the crane 100 that are related to the first winch WC1 and the second winch WC2.

[0026] As shown in Figures 1 to 3, the first winch WC1 includes 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 40, and a reduction gear 47. Similarly, the second winch WC2 includes 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 40, and a reduction gear 47.

[0027] The first winch rope R1 is an opening / 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 for paying out and reeling in the first winch rope R1 as the opening / closing rope, and the second winch drum DR2 is a support drum for paying out and reeling in the second winch rope R2 as the support rope.

[0028] The first winch drum DR1 is supported by a support member (not shown) on the upper slewing body 102 so as to be rotatable around a horizontal axis, enabling the first winch rope R1 to be paid out and retracted. The second winch drum DR2 is supported by a support member (not shown) on the upper slewing body 102 so as to be rotatable around a horizontal axis, enabling the second winch rope R2 to be paid out and retracted.

[0029] The first winch drum DR1 and the second winch drum DR2 are positioned at different locations from each other. In this embodiment, the first winch drum DR1 and the second winch drum DR2 are located behind the luffing member 104, and the second winch drum DR2 is located behind the first winch drum DR1. However, the first winch drum DR1 may be located behind the second winch drum DR2.

[0030] The longitudinal direction is based on the orientation of the upper rotating body 102. Specifically, the horizontal direction from the counterweight 115 toward the cabin 114 is forward, and the opposite direction is backward. The lateral direction is the horizontal direction perpendicular to the longitudinal direction.

[0031] The first point sheave 105 and the second point sheave 106 are arranged side by side and attached to the upper end of the undulating member 104. The first idler sheave 112 and the second idler sheave 113 are arranged side by side and attached to the upper end of the undulating member 104. The first idler sheave 112 is located behind the first point sheave 105, and the second idler sheave 113 is located behind the second point sheave 106.

[0032] The first winch rope R1 extends from the first winch drum DR1 to the upper end of the luffing member 104, hangs down from the upper end, and is connected to the bucket device 10. Specifically, the first winch rope R1 is supported by the first idler sheave 112 and the first point sheave 105, and hangs down from the first point sheave 105. The second winch rope R2 extends from the second winch drum DR2 to the upper end of the luffing member 104, hangs down from the upper end, and is connected to the bucket device 10. Specifically, the second winch rope R2 is supported by the second idler sheave 113 and the second point sheave 106, and hangs down from the second point sheave 106. The lower ends (tips) of the first winch rope R1 and the second winch rope R2 are each connected to the bucket device 10.

[0033] The bucket device 10 is a working device known as a clamshell bucket. The bucket device 10 has buckets 13, 13 to which a first winch rope R1 and a second winch rope R2 are connected, and which can be opened and closed and raised and lowered in accordance with the operation of the first winch drum DR1 and the second winch drum DR2.

[0034] Specifically, as shown in Figure 4, 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. The right side of Figure 4 shows the open state in which the buckets 13, 13 of the bucket device 10 are open, and the left side of Figure 4 shows the closed state in which the buckets 13, 13 of the bucket device 10 are closed.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] The first winch rope R1 (the opening / closing rope) is wrapped 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 (the support rope) is fixed to the upper member 11.

[0039] The first winch motor 34 and the second winch motor 35 are variable displacement hydraulic motors connected to a 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 or 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 or 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).

[0040] 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.

[0041] The first clutch brake 40 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 unwound from the first winch drum DR1 by the weight of the bucket device 10. The first clutch brake 40 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.

[0042] Similarly, the second clutch brake 40 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 40 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.

[0043] The aforementioned connection state allows the first winch rope R1 and the second winch rope R2 to be unwound and wound up by the driving force of the first winch motor 34 and the second winch motor 35. That is, when the first winch motor 34 and the second winch motor 35 are driven in the aforementioned connection state, the driving force of the first winch motor 34 and the second winch motor 35 is transmitted to the first winch drum DR1 and the second winch drum DR2, respectively, via the reduction gears 47, 47. When the first winch drum DR1 and the second winch drum DR2 rotate, the first winch rope R1 and the second winch rope R2 are unwound or wound up.

[0044] The free state is a state in which the first winch rope R1 and the second winch rope R2 can be unfurled from the first winch drum DR1 and the second winch drum DR2 by the tension of the first winch rope R1 and the second winch rope 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 winch rope R1 and the second winch rope R2 can be unfurled from the first winch drum DR1 and the second winch drum DR2 without rotating the first winch motor 34 and the second winch motor 35 in the unfurling direction of the first winch rope R1 and the second winch rope R2.

[0045] Furthermore, the first clutch brake 40 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 40 can apply a second braking force to the second winch drum DR2, that is, it can brake the second winch drum DR2.

[0046] 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 40 and the second braking force of the second clutch brake 40 are sufficient to keep the bucket device 10 stationary without free-falling, and to stop the bucket device 10 if it is free-falling.

[0047] In this embodiment, each of the first clutch brake 40 and the second clutch brake 40 is a so-called wet brake and comprises 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 lubricating oil.

[0048] 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 40 and the second clutch brake 40 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 40 and the second clutch brake 40 each enter the connected state when the multiple brake discs 41 come into contact with each other.

[0049] More specifically, each of the first clutch brake 40 and the second clutch brake 40 is equipped with a spring 46, and each of the first clutch brake 40 and the second clutch brake 40 has a pair of oil chambers 43, 44 formed therein, and the piston 42 has a flange 45 separating 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.

[0050] The crane 100 includes a first control valve 32, a second control valve 33, a first payout proportional valve 61A, a first retraction proportional valve 61B, a second payout proportional valve 63A, a second retraction proportional valve 63B, a first brake proportional valve 62, a second brake proportional valve 64, and a plurality of operating devices. In this embodiment, each of the proportional valves 61A, 61B, 62, 63A, 63B, and 64 is an electromagnetic proportional pressure reducing valve.

[0051] 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 control valve 32 and the second control valve 33 is composed of a hydraulic pilot switching valve having a pair of pilot ports.

[0052] The pair of pilot ports are an unwinding pilot port and a winding pilot port. When no pilot pressure is applied to either pilot port, the first control valve 32 and the second control valve 33 are held in a neutral position, shutting off the winch motor corresponding to the control valve (hereinafter referred to as the "corresponding winch motor") from the hydraulic pump 31. When pilot pressure is applied to the unwinding pilot port, the first control valve 32 and the second control valve 33 open 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. When pilot pressure is applied to the winding pilot port, the first control valve 32 and the second control valve 33 open to form an oil passage for rotating the corresponding winch motor in the winding direction, that is, an oil passage for supplying hydraulic fluid from the hydraulic pump 31 to the corresponding winch motor in the winding direction. The opening degrees of the first control valve 32 and the second control valve 33 increase with increasing pilot pressure to allow the hydraulic fluid to flow at a flow rate corresponding to the pilot pressure input to the control valve.

[0053] The first pay-out proportional valve 61A outputs a pilot pressure to control the pay-out operation of the first winch drum DR1. The first pay-out proportional valve 61A is interposed between a pilot hydraulic power source (not shown) and the pay-out pilot port of the first control valve 32. When a first pay-out command (current command value), which is an electrical signal, is input to the proportional valve 61A from the controller 70 (described later), the valve opens to allow a pilot pressure proportional to the first pay-out command to be input to the pay-out pilot port.

[0054] The first winding proportional valve 61B outputs a pilot pressure to control the winding operation of the first winch drum DR1. The first winding proportional valve 61B is interposed between the pilot hydraulic power source and the winding pilot port of the first control valve 32, and opens to allow a pilot pressure proportional to the first winding command to be input to the winding pilot port when a first winding command (current command value), which is an electrical signal, is input to the proportional valve 61B from the controller 70.

[0055] The second pay-out proportional valve 63A outputs a pilot pressure to control the pay-out operation of the second winch drum DR2. The second pay-out proportional valve 63A is interposed between a pilot hydraulic power source (not shown) and the pay-out pilot port of the second control valve 33, and opens to allow a pilot pressure proportional to the second pay-out command to be input to the pay-out pilot port when a second pay-out command (current command value), which is an electrical signal, is input to the proportional valve 63A from the controller 70.

[0056] The second winding proportional valve 63B outputs a pilot pressure to control the winding operation of the second winch drum DR2. The second winding proportional valve 63B is interposed between the pilot hydraulic power source and the winding pilot port of the second control valve 33, and opens to allow a pilot pressure proportional to the second winding command to be input to the winding pilot port when a second winding command (current command value), which is an electrical signal, is input to the proportional valve 63B from the controller 70.

[0057] The first proportional brake valve 62 is interposed between the pilot hydraulic power source P and the first clutch brake 40. When a first brake command (current command value), 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 40. As a result, the first proportional brake valve 62 can switch the state of the first clutch brake 40 between the free state and the connected state.

[0058] Similarly, the second proportional brake valve 64 is interposed between the pilot hydraulic power source P and the second clutch brake 40. When a second brake command (current command value), 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 40. As a result, the second proportional brake valve 64 can switch the state of the second clutch brake 40 between the free state and the connected state.

[0059] As shown in Figures 1 to 3, the multiple operating devices include a first winch operating device 51, a second winch operating device 53, a first brake operating device 52, a second brake operating device 54, and a luffing operating device 55 (see Figure 1).

[0060] As shown in Figure 2, the first winch operating device 51 includes a first winch operating lever 51A and a first lever input detector 51B. The second winch operating device 53 includes a second winch operating lever 53A and a second lever input detector 53B. The first brake operating device 52 includes a first brake operating pedal 52A and a first pedal input detector 52B. The second brake operating device 54 includes a second brake operating pedal 54A and a second pedal input detector 54B. As shown in Figure 1, the luffing operating device 55 includes a luffing operating lever 55A and a luffing lever input detector 55B.

[0061] The first winch operating lever 51A is an operating member to which an operator performs a first lever operation to specify the rotation direction and rotation speed of the first winch drum DR1. Specifically, the first winch operating lever 51A is provided with either a first payout operation to rotate the first winch drum DR1 in the payout direction to pay out 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 lever operation.

[0062] The first lever input detector 51B detects the amount of the first lever operation (extend or retract operation) applied to the first winch operating lever 51A, and inputs the detection result to the controller 70.

[0063] Similarly, the second winch operating lever 53A is an operating member to which a second lever operation is performed by an operator to specify the rotation direction and rotation 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 lever operation.

[0064] The second lever input detector 53B detects the amount of operation of the second lever (extension operation or winding operation) applied to the second winch operating lever 53A, and inputs the detection result to the controller 70.

[0065] The first brake operation pedal 52A is an operating member to which a first pedal operation is performed by an operator to specify a first braking force on the first winch drum DR1. The first pedal input detector 52B detects the amount of the first pedal operation applied to the first brake operation pedal 52A and inputs the detection result to the controller 70.

[0066] The second brake operation pedal 54A is an operating member to which a second pedal operation is performed by the operator to specify a second braking force on the second winch drum DR2. The second pedal input detector 54B detects the amount of the second pedal operation applied to the second brake operation pedal 54A and inputs the detection result to the controller 70.

[0067] The luffing lever 55A is an operating member that allows an operator to perform luffing operations to specify the rotation direction and rotation speed of the luffing winch drum DR3. Specifically, the luffing lever 55A is provided with either a lowering operation to rotate the luffing winch drum DR3 in the unwinding direction to unwind the luffing rope R3, or an uprighting operation to rotate the luffing winch drum DR3 in the winding direction to wind up the luffing rope R3.

[0068] The luffing lever input detector 55B detects the amount of luffing operation (lowering operation or raising operation) applied to the luffing operation lever 55A and inputs the detection result to the controller 70.

[0069] When the luffing lever 55A is lowered, hydraulic fluid discharged from the hydraulic pump 31 is supplied to the luffing motor, which is a hydraulic motor not shown in the figure. As a result, the luffing member 104 performs a lowering operation in which the luffing angle θ, described later, gradually decreases. When the luffing lever 55A is raised, hydraulic fluid discharged from the hydraulic pump 31 is supplied to the luffing motor. As a result, the luffing member 104 performs a raised operation in which the luffing angle θ gradually increases. The luffing operation includes the lowering operation and the raised operation.

[0070] The crane 100 includes a luffing member angle detector 22, a first drum rotation detector 81, and a second drum rotation detector 82.

[0071] The luffing member angle detector 22 detects the luffing angle θ of the luffing member 104 and inputs the detection result to the controller 70. In this embodiment, the luffing member angle detector 22 detects the boom angle, which is the angle of the boom of the luffing member 104, as the luffing angle θ. The luffing angle θ is the angle of the luffing member 104 with respect to a predetermined reference. The reference may be, for example, a horizontal line or a horizontal plane, another straight line or another plane, the upper slewing body 102, or the lower body 101.

[0072] The first drum rotation detector 81 detects a first rotation amount ωm, which is the amount of rotation of the first winch drum DR1, and inputs the detection result to the controller 70. The second drum rotation detector 82 detects a second rotation amount ωa, which is the amount of rotation of the second winch drum DR2, and inputs the detection result to the controller 70.

[0073] Next, the synchronization control device 200 according to this embodiment will be described.

[0074] The synchronization control device 200 is a control device for the crane 100. In this embodiment, the synchronization control device 200 is provided on the crane 100.

[0075] The synchronization control device 200 includes a controller 70. The controller 70 can select either power synchronization control or tension synchronization control. The power synchronization control is a control to reduce the deviation between a physical quantity correlated with the amount of payout of the first winch rope R1 and a physical quantity correlated with the amount of payout of the second winch rope R2 when raising the bucket device 10. The tension synchronization control is a control to reduce the tension deviation, which is the deviation between the tension T1 (see Figure 4) acting on the first winch rope R1 and the tension T2 (see Figure 4) acting on the second winch rope R2 when raising the bucket device 10.

[0076] In this embodiment, when the controller 70 selects and executes the power synchronization control, the deviation between the physical quantity correlated with the amount of the first winch rope R1 extended and the physical quantity correlated with the amount of the second winch rope R2 extended becomes smaller when the bucket device 10 is raised. This makes it easier to maintain the open and closed states of the buckets 13, 13.

[0077] On the other hand, when the controller 70 selects and executes the tension synchronization control, the difference (the tension deviation) between the tension T1 acting on the first winch rope R1 and the tension T2 acting on the second winch rope R2 when the bucket device 10 is raised becomes smaller. This tension synchronization control is effective when the load on the bucket device 10 is large when it is raised (winding operation), specifically, for example, when the weight of the object being transported held by the bucket device 10 is large. When the load on the bucket device 10 is large when it is raised, if the tension deviation becomes large, the bucket device 10 may rotate around its vertical axis when it is raised. When the controller 70 executes the tension synchronization control and the tension deviation becomes smaller, the rotation of the bucket device 10 when it is raised is suppressed.

[0078] The controller 70 comprises a computer having an arithmetic processing unit and memory. The power synchronization control and tension synchronization control performed by the controller 70 are realized by the arithmetic processing unit executing a control program stored in the memory.

[0079] In the power synchronization control, it is preferable that the controller 70 performs feedback control based on the deviation between a physical quantity correlated with the payout amount of the first winch rope R1 and a physical quantity correlated with the payout amount of the second winch rope R2. This makes it possible to effectively reduce the deviation between the physical quantity correlated with the payout amount of the first winch rope R1 and the physical quantity correlated with the payout amount of the second winch rope R2 when the bucket device 10 is raised in the power synchronization control.

[0080] In the aforementioned power synchronization control, the deviation between the physical quantity correlated with the payout amount of the first winch rope R1 and the physical quantity correlated with the payout amount of the second winch rope R2 is preferably zero from the viewpoint of maintaining the open and closed states of the buckets 13, 13. The physical quantity correlated with the payout amount of the first winch rope R1 may be the payout amount of the first winch rope R1 itself, or it may be the lifting height value of the first winch rope R1 as described later. Similarly, the physical quantity correlated with the payout amount of the second winch rope R2 may be the payout amount of the second winch rope R2 itself, or it may be the lifting height value of the second winch rope R2 as described later. Therefore, the power synchronization control may be a control to reduce the payout amount deviation Ek(z), which is the difference between the payout amount of the first winch rope R1 and the payout amount of the second winch rope R2, or it may be a control to reduce the lift value deviation Ey(z), which is the difference between the lift value of the first winch rope R1 and the lift value of the second winch rope R2. Furthermore, the power synchronization control may be a control to reduce the power synchronization deviation E(z), which is calculated using the payout amount deviation Ek(z) and the lift value deviation Ey(z), as described later.

[0081] The controller 70 can calculate the amount of the first winch rope R1 to be unwound based on a first rotation amount ωm input from the first drum rotation detector 81. The controller 70 can also calculate the amount of the second winch rope R2 to be unwound based on a second rotation amount ωa input from the second drum rotation detector 82.

[0082] The controller 70 may calculate the lifting height of the first winch rope R1 and the lifting height of the second winch rope R2 as follows, for example.

[0083] The lifting height values ​​of the winch ropes (the lifting height values ​​of the first winch rope R1 and the second winch rope R2, respectively) are physical quantities correlated with the amount of winch rope unwound, and are values ​​that take into account the influence of changes in the luffing angle θ of the luffing member 104. When the position of a predetermined part of the winch rope in the reference state is taken as the reference (zero position), the amount of change in the position of the predetermined part of the winch rope relative to this reference is called the lifting height value of the winch rope. The predetermined part of the winch rope may be, for example, the tip of the winch rope, or it may be any other part of the winch rope. The reference state is, for example, a state in which the winch rope has been unwound a predetermined length from the winch drum, and the luffing angle θ of the luffing member 104 is a predetermined angle θs.

[0084] More specifically, the reference state may be, for example, the state in which the winch rope is fully extended from the winch drum and the luffing angle θ of the luffing member 104 is 45 degrees. In this case, the lifting value of the first winch rope R1 is as follows. That is, with the position of the tip of the first winch rope R1 as the reference point in the state in which the first winch rope R1 is fully extended from the first winch drum DR1 and the luffing angle θ of the luffing member 104 is 45 degrees, the lifting value of the first winch rope R1 is the amount of change in the position of the tip of the first winch rope R1 relative to this reference point. Similarly, the lifting value of the second winch rope R2 is as follows. In other words, the lifting height of the second winch rope R2 is the amount of change in the position of the tip of the second winch rope R2 relative to the reference position when the second winch rope R2 is fully extended from the second winch drum DR2 and the luffing angle θ of the luffing member 104 is 45 degrees.

[0085] The lifting height 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 angle θ of the luffing member 104. Similarly, the lifting height 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 angle θ of the luffing member 104.

[0086] The controller 70 uses information such as specification data including the length of the luffing member 104, data on 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 on the relative position of the second winch drum DR2 with respect to the said specific part of the luffing member 104, as well as detection results input to the controller 70 from drum rotation detectors 81 and 82, and the luffing angle θ of the luffing member 104 input to the controller 70 from the luffing member angle detector 22, to calculate the lifting height values ​​of the first winch rope R1 and the second winch rope R2, respectively.

[0087] Here, the distance from the first winch drum DR1 to the upper end P1 of the luffing member 104 is defined as the first distance L. top-m The distance from the second winch drum DR2 to the upper end P2 of the luffing member 104 is called the second distance L. top-a The controller 70 is located at a first distance L relative to the reference state. top-m The lifting height value Lh1 of the first winch rope R1 may be calculated based on the change in ΔL1, the change in the height position of the upper end P1 of the luffing member 104 relative to the reference state ΔH1, and the change in the amount of the first winch rope R1 extended relative to the reference state ΔR1. The controller 70 may calculate the lifting height value Lh1 of the first winch rope R1 using, for example, the following equation (1).

[0088] The lifting height of the first winch rope R1 is Lh1 = -(ΔL1 + ΔH1 + ΔR1) (1)

[0089] Similarly, the controller 70 controls the second distance L relative to the reference state. top-a The lifting height value Lh2 of the second winch rope R2 may be calculated based on the change in ΔL2, the change in the height position of the upper end P2 of the luffing member 104 relative to the reference state ΔH, and the change in the amount of the second winch rope R2 extended relative to the reference state ΔR2. The controller 70 may calculate the lifting height value Lh2 of the second winch rope R2 using, for example, the following equation (2).

[0090] The lifting height of the second winch rope R2 is Lh2 = -(ΔL2 + ΔH2 + ΔR2) (2)

[0091] Here, we assume that the upper end P1 and the upper end P2 of the luffing member 104 are at the same height, and that the amount of the first winch rope R1 and the amount of the second winch rope R2 are both zero during the process in which the luffing angle θ of the luffing member 104 changes from θ1 to θ2. In this case, the lift value deviation Ey(z), which is the difference between the lift value Lh1 of the first winch rope R1 and the lift value Lh2 of the second winch rope R2 when the luffing angle θ changes from θ1 to θ2, can be expressed, for example, by the following equation (3). That is, when the luffing angle θ of the luffing member 104 changes from θ1 to θ2 with the first winch drum DR1 and the second winch drum DR2 stopped, the lift value deviation Ey(z) can be expressed, for example, by the following equation (3).

[0092] Ey(z) = ΔL2 - ΔL1 (3)

[0093] The following describes an example of a method by which the controller 70 calculates the power synchronization error E(z) using the head value error Ey(z) and the payout error Ek(z).

[0094] The controller 70 may calculate the power synchronization error E(z) by using a calculation formula that constructs a complementary filter of these deviations using the head value deviation Ey(z) and the payout deviation Ek(z). Such a calculation formula for the power synchronization error E(z) may be, for example, the following formula (4).

[0095]

number

[0096] G in equation (4) LPF (z) is a low-pass filter. The low-pass filter may be a digital filter. The digital filter may be an FIR filter (FIR: Finite Impulse Response), such as a moving average filter, or an IIR filter (IIR: Infinite Impulse Response). The low-pass filter may also be a low-pass filter containing a capacitor and a resistor, or a low-pass filter containing an inductor and a capacitor.

[0097] According to equation (4) above, the controller 70 can calculate the power synchronization error E(z).

[0098] Next, the controller 70 takes the power synchronization error E(z) as input and performs filtering, obtaining the output of the filtering process. This output is used as a feedback control value for the target speed. Since the controlled object can be considered as an integrator with a delay in the hydraulic equipment, the filter for the filtering process is determined by designing the feedback control system to ensure the stability of the integrator. The filtering process involves strengthening or weakening a specific frequency band while maintaining that specific frequency band. The frequency characteristics of the filtering process are designed appropriately according to the characteristics of the hydraulic equipment. The dynamic characteristics (controlled object) of the crane 100 controlled by the controller 70 are the amount of deviation caused by the speed difference determined by the two proportional valve current command values ​​for the two proportional valves (first winding proportional valve 61B and second winding proportional valve 63B). Since the speed difference becomes a deviation when integrated, the controlled object can be considered as an integrator. The delay in the hydraulic equipment means that the speed becomes a steady value with a certain delay in the hydraulic equipment. The delay of the hydraulic equipment includes, for example, the response delay of a proportional valve. The delay of the hydraulic equipment is represented, for example, by a transfer function that represents the delay. The feedback control system may be represented, for example, by multiplying the integrator by the transfer function.

[0099] Next, the controller 70 determines the ratio of the feedback control value to the first winch rope R1 and the second winch rope R2.

[0100] For example, when the bucket device 10 is raised, i.e., during hoisting, if the hoisting speed of the first winch rope R1 is relatively slower than that of the second winch rope R2, that is, if the hoisting speed of the first winch rope R1 needs to be relatively increased, it is possible to reduce the power synchronization error E(z) by either increasing the hoisting speed of the first winch rope R1 or decreasing the hoisting speed of the second winch rope R2.

[0101] The controller 70 may determine the increasing component of the winding speed of the first winch rope R1 and the decreasing component of the winding speed of the second winch rope R2 based on the amount of winding operation performed on the first winch operating lever 51A of the first winch operating device 51 at that time.

[0102] Specifically, if the amount of winding operation applied to the first winch operating lever 51A is in the full lever range where the winding speed cannot be increased, the controller 70 reduces the power synchronization error E(z) by reducing the winding speed of the second winch rope R2. On the other hand, if the amount of winding operation applied to the first winch operating lever 51A is in the slow speed range where the winding speed cannot be decreased, the controller 70 reduces the power synchronization error E(z) by increasing the winding speed of the first winch rope R1. With this allocation, the controller 70 can determine the target speed such that the power synchronization error E(z) decreases smoothly in any lever range. The target winding speed of the first winch rope R1 and the target winding speed of the second winch rope R2 are expressed by the following equations (5) and (6).

[0103]

number

[0104]

number

[0105] In equations (5) and (6), v FB This is a feedback control value calculated based on the power synchronization deviation E(z), and v main This is the feedback component of the target speed of the first winch rope R1, and v aux is the feedback component of the target speed of the second winch rope R2, and α is the allocation rate.

[0106] The controller 70 determines the allocation rate α at that time based on a predetermined map such as a relational expression or lookup table that represents the relationship between the operating direction and amount of the first winch operating lever 51A and the allocation rate α.

[0107] Next, the controller 70 calculates the pilot pressure corresponding to the target speed of the first winch rope R1 based on a predetermined map such as a relational expression representing the relationship between the target speed and the pilot pressure, or a lookup table. Then, the controller 70 calculates the current command value (first current command value) corresponding to the pilot pressure based on a predetermined map such as a relational expression representing the relationship between the pilot pressure and the current command value, or a lookup table. Similarly, the controller 70 calculates the pilot pressure corresponding to the target speed of the second winch rope R2 based on a predetermined map, and calculates the current command value (second current command value) corresponding to the pilot pressure based on a predetermined map. Then, the controller 70 inputs the first current command value to the first winding proportional valve 61B and the second current command value to the second winding proportional valve 63B.

[0108] The controller 70 can reduce the power synchronization deviation E(z) when raising the bucket device 10 by performing power synchronization control including the feedback control described above. As the power synchronization deviation E(z) decreases, the payout deviation Ek(z) also decreases, and the lifting value deviation Ey(z) also decreases.

[0109] In the above example, the controller 70 calculates the pilot pressure corresponding to the target speed as an intermediate calculated value correlated with the current command value, but it is not limited to the above example. The controller 70 may also calculate the target speed of the winch rope or the target speed of the winch drum as an intermediate calculated value correlated with the current command value, or it may calculate the target motor flow rate, which is the flow rate of the hydraulic fluid flowing into the winch motor, as an intermediate calculated value correlated with the current command value.

[0110] The crane 100 further comprises a first constant horsepower control valve 65 and a second constant horsepower control valve 66. As shown in Figure 3, the first constant horsepower control valve 65 is connected to conduits 34A and 34B, which are respectively connected to a pair of ports of the first winch motor 34. The second constant horsepower control valve 66 is connected to conduits 35A and 35B, which are respectively connected to a pair of ports of the second winch motor 35.

[0111] The first constant horsepower control valve 65 is a control valve that adjusts the capacity of the first winch motor 34 in accordance with the load acting on the first winch motor 34 to keep the output of the first winch motor 34 constant. In other words, the first constant horsepower control valve 65 adjusts the capacity of the first winch motor 34 in accordance with the differential pressure between the pressure in pipeline 34A and the pressure in pipeline 34B to keep the output (horsepower) of the first winch motor 34 constant.

[0112] The second constant horsepower control valve 66 is a control valve that adjusts the capacity of the second winch motor 35 in accordance with the load acting on the second winch motor 35 to keep the output of the second winch motor 35 constant. In other words, the second constant horsepower control valve 66 adjusts the capacity of the second winch motor 35 in accordance with the differential pressure between the pressure in pipeline 35A and the pressure in pipeline 35B to keep the output (horsepower) of the second winch motor 35 constant.

[0113] Figure 11 is a circuit diagram showing an example of a first constant horsepower control valve 65. The first constant horsepower control valve 65 is connected to pipelines 34A and 34B. The first constant horsepower control valve 65 includes a pressure compensation valve 36 connected to pipelines 34A and 34B, a spool valve 37 connected to the pressure compensation valve 36, and a tilt angle control device 38 connected to the spool valve 37 and pipeline 34B for controlling the tilt angle of the first winch motor 34. The first constant horsepower control valve 65 operates to maintain the differential pressure ΔP between the pressure PA in pipeline 34A and the pressure PB in pipeline 34B at a predetermined set pressure. The first constant horsepower control valve 65 increases the motor capacity when the differential pressure ΔP is about to exceed the set pressure, and decreases the motor capacity when the differential pressure ΔP is about to exceed the set pressure. Through this operation, the first constant horsepower control valve 65 controls the horsepower (output) of the first winch motor 34 to a constant level, thereby maintaining a constant output (horsepower) of the first winch motor 34. The second constant horsepower control valve 66 has the same structure as the first constant horsepower control valve 65.

[0114] In the tension synchronization control, the controller 70 inputs the same current command value to the first winding proportional valve 61B and the second winding proportional valve 63B. In the tension synchronization control, the controller 70 does not perform feedback control (i.e., feedback control like the power synchronization control) based on the deviation between the amount of the first winch rope R1 paid out and the amount of the second winch rope R2 paid out, and inputs the same current command value to the first winding proportional valve 61B and the second winding proportional valve 63B.

[0115] In the tension synchronization control described above, the controller 70 inputs the same current command value to the first winding proportional valve 61B and the second winding proportional valve 63B, causing the first winch drum DR1 and the second winch drum DR2 to perform a winding operation to wind up the first winch rope R1 and the second winch rope R2, respectively, so that the bucket device 10 rises. When the bucket device 10 rises, the tension T1 acting on the first winch rope R1 and the tension T2 acting on the second winch rope R2 are mechanically adjusted by the first constant horsepower control valve 65 and the second constant horsepower control valve 66, respectively. In other words, the load acting on the first winch motor 34 is a value correlated with tension T1, and the load acting on the second winch motor 35 is a value correlated with tension T2. ​​Therefore, tensions T1 and T2 are controlled to approximately the same value by the first constant horsepower control valve 65 and the second constant horsepower control valve 66. Accordingly, the controller 70 can raise the bucket device 10 while reducing the deviation between the tension T1 acting on the first winch rope R1 and the tension T2 acting on the second winch rope R2 by performing the tension synchronization control which involves inputting the same current command value to the first winding proportional valve 61B and the second winding proportional valve 63B. Specifically, this is as follows.

[0116] When the tension T1 acting on the first winch rope R1 increases and the load acting on the first winch motor 34 increases, the first constant horsepower control valve 65 increases the capacity of the first winch motor 34, so the rotational speed of the first winch drum DR1 decreases. On the other hand, when the tension T1 acting on the first winch rope R1 decreases and the load acting on the first winch motor 34 decreases, the first constant horsepower control valve 65 decreases the capacity of the first winch motor 34, so the rotational speed of the first winch drum DR1 increases.

[0117] Similarly, when the tension T2 acting on the second winch rope R2 increases and the load acting on the second winch motor 35 increases, the second constant horsepower control valve 66 increases the capacity of the second winch motor 35, so the rotational speed of the second winch drum DR2 decreases. On the other hand, when the tension T2 acting on the second winch rope R2 decreases and the load acting on the second winch motor 35 decreases, the second constant horsepower control valve 66 decreases the capacity of the second winch motor 35, so the rotational speed of the second winch drum DR2 increases.

[0118] Therefore, for example, if the rotational speed of the first winch drum DR1 is greater than that of the second winch drum DR2, causing the tension T1 acting on the first winch rope R1 to increase and the tension T2 acting on the second winch rope R2 to decrease, the capacity of the first winch motor 34 increases, causing the rotational speed of the first winch drum DR1 to decrease, while the capacity of the second winch motor 35 decreases, causing the rotational speed of the second winch drum DR2 to increase. As a result, the tension T1 acting on the first winch rope R1 decreases and the tension T2 acting on the second winch rope R2 increases. In other words, the first constant horsepower control valve 65 and the second constant horsepower control valve 66 operate to reduce the deviation between the tension T1 acting on the first winch rope R1 and the tension T2 acting on the second winch rope R2 when the bucket device 10 is raised. Therefore, the controller 70 can raise the bucket device 10 while reducing the difference between the tension T1 acting on the first winch rope R1 and the tension T2 acting on the second winch rope R2 by performing the tension synchronization control when raising the bucket device 10.

[0119] In the tension synchronization control described above, the controller 70 may determine a current command value in response to the first winding operation and input the determined current command value to the first winding proportional valve 61B and the second winding proportional valve 63B. Alternatively, in the tension synchronization control described above, the controller 70 may determine a current command value in response to the second winding operation and input the determined current command value to the first winding proportional valve 61B and the second winding proportional valve 63B.

[0120] Figure 5 is an example of a map showing the relationship between the amount of winding operation received by the winch operating device and the target pilot pressure. Figure 6 is an example of a map showing the relationship between the target pilot pressure and the command current value. In the tension synchronization control, the controller 70 may determine a target pilot pressure corresponding to the amount of the first winding operation based on the amount of the first winding operation input from the first lever input detector 51B and the map shown in Figure 5, and then determine a current command value corresponding to the target pilot pressure based on the determined target pilot pressure and the map shown in Figure 6, and input the determined current command value to the first winding proportional valve 61B and the second winding proportional valve 63B.

[0121] The crane 100 further includes an input device 23 (see Figure 2) capable of receiving input from an operator. Based on the input received by the input device 23, the controller 70 selects either the power synchronization control or the tension synchronization control and executes the selected control. The input device 23 switches the power synchronization control on and off (the feedback control on and off) based on the operator's input. That is, when the controller 70 receives a signal from the input device 23 indicating that the power synchronization control has been selected, it executes the power synchronization control, and when the controller 70 receives a signal from the input device 23 indicating that the tension synchronization control has been selected (a signal indicating that the power synchronization control has not been selected), it executes the tension synchronization control.

[0122] Figure 7 shows an example of the display screen of the input device 23. When the operator selects one of the two options displayed on the display screen shown in Figure 7, namely the power synchronization control selection button and the tension synchronization control selection button, the input device 23 inputs a signal corresponding to the operator's selection to the controller 70. Based on this signal, the controller 70 selects either the power synchronization control or the tension synchronization control and executes the selected control. Note that in Figure 7, the color or image of the button selected by the operator changes. The input device 23 may be the operator setting device 21, which will be described later.

[0123] Figure 8 is a flowchart showing an example of the calculation process for power synchronization control performed by the controller 70.

[0124] When the control mode of the crane 100 is set to power synchronization mode, the controller 70 performs the calculation processing shown in the flowchart of Figure 8. When the control mode is set to power synchronization mode, the controller 70 performs power synchronization control or tension synchronization control. Power synchronization control and tension synchronization control, respectively, are controls that synchronize the operation of the first winch drum DR1 and the operation of the second winch drum DR2 with simple operation by the operator.

[0125] The controller 70 may, for example, set the control mode of the crane 100 to the power-synchronized mode based on a mode input entered by the operator into the input device 23 to select a control mode. Alternatively, the controller 70 may set the control mode of the crane 100 to the power-synchronized mode based on the state of the mode switches 90 and 91, as shown in the modified example described later.

[0126] In step S11, the controller 70 determines whether or not to apply feedback control in the power synchronization mode. If the signal input from the input device 23 is a signal corresponding to the power synchronization control, that is, if feedback control is to be applied in the power synchronization mode (YES in step S11), the controller 70 performs the processing in steps S12 to S16 (the power synchronization control). On the other hand, if the signal input from the input device 23 is a signal corresponding to the tension synchronization control, that is, if feedback control is not to be applied in the power synchronization mode (NO in step S11), the controller 70 performs the processing in step S17 (the tension synchronization control).

[0127] In step S12, the controller 70 calculates the power synchronization error E(z).

[0128] In step S13, the controller 70 performs filtering on the calculated deviation as input and obtains a feedback control value of the target speed as its output.

[0129] In step S14, the controller 70 determines the application ratio (allocation rate α) of the feedback control value.

[0130] In step S15, the controller 70 converts the target speed into pilot pressure.

[0131] In step S16, the controller 70 inputs a current command value to the proportional valve.

[0132] In step S17, the controller 70 performs the tension synchronization control. In step S17, the controller 70 inputs the same current command value to the first winding proportional valve 61B and the second winding proportional valve 63B. That is, the controller 70 does not perform the feedback control. The controller 70 sets the feedback control value to zero and converts the amount of winding operation received by the winch operating device into pilot pressure, or converts the target speed corresponding to the amount of winding operation into pilot pressure. Then, the controller 70 converts the pilot pressure into a current command value and inputs the current command value to the proportional valves 61B and 63B, respectively.

[0133] The main features of the tuning control device 200 according to this embodiment are as described above. Below, modifications including other features of the tuning control device 200 will be described, but the tuning control device in this disclosure is not limited to the following modifications.

[0134] Figure 9 is a block diagram showing the controller 70 and related main components of the tuning control device 200 according to a modified example of this embodiment. Figure 10 is a flowchart showing an example of the calculation processing performed by the controller 70 of the tuning control device 200 according to a modified example.

[0135] The basic configuration of the modified synchronization control device 200 and the basic configuration of the crane 100 equipped with the modified synchronization control device 200 are the same as those of the configuration of the synchronization control device 200 and the crane 100 described with reference to Figures 1 to 8 in the above embodiment. The modified synchronization control device 200 selects one mode from a predetermined number of modes based on predetermined conditions and sets the control mode of the crane 100 to the selected mode.

[0136] As shown in Figure 9, the modified crane 100 includes an operator setting device 21, a first drum rotation detector 81, a second drum rotation detector 82, a luffing member angle detector 22, at least one mode switch, lever input detectors 51B, 53B, 55B, pedal input detectors 52B, 54B, load value detector 94, and a setting memory 95 (previous setting memory).

[0137] The first drum rotation detector 81, the second drum rotation detector 82, the undulation member angle detector 22, the lever input detectors 51B, 53B, 55B, and the pedal input detectors 52B, 54B are the same as those described above for the embodiment.

[0138] The operator setting device 21 is an input device for the operator to input various settings necessary for the operation of the crane 100 according to the modified example. The operator setting device 21 receives input from the operator for making the various settings. The operator setting device 21 may be located, for example, inside the cabin 114. The operator setting device 21 may include, for example, a monitor touch panel. The various settings may include, for example, specification data for the main components constituting the construction machine, such as the luffing member 104, winch drums DR1 and DR2, and bucket device 10. The various settings may include, for example, the winding state of the winch ropes of the winch drums DR1 and DR2 at the start of work (for example, a value indicating how much of the winch rope is wound on the winch drum).

[0139] The at least one mode switch may include, for example, an on / off mode switch 90 and an assist mode switch 91.

[0140] The load value detector 94 detects a load value that correlates with the bucket weight, which is the weight of the bucket device 10. The load value detector 94 may be, for example, a load cell. The load value detector 94 may be attached to the lower spreader 110, for example, as shown in Figure 1, to detect the load value acting on the luffing rope R3. However, the mounting position of the load value detector 94 is not limited to the lower spreader 110. For example, the load value detector 94 may be attached to the upper spreader 109 to detect the load value acting on the luffing rope R3. Alternatively, the load value detector 94 may detect the load value acting on the guy line 108.

[0141] The setting memory 95 stores the weight of the bucket device 10 calculated by the bucket weight calculation unit 73, which will be described later. Specifically, the setting memory 95 may store the bucket weight as the previous setting value when the power to the controller 70 is turned off. Then, in the next operation, the controller 70 may use the previous setting value stored in the setting memory 95 as the bucket weight.

[0142] In this modified example, the controller 70 sets the control mode of the crane 100 to one of several modes based on a preset determination condition. The multiple control modes may include an assist mode and a non-assist mode. The assist mode includes a bucket opening / closing mode, a power synchronization mode, and a free synchronization mode.

[0143] The assist mode is a control mode in which the controller 70 performs assist control to enable the operator to make the bucket device 10 perform predetermined operations with simple operations. The non-assist mode is a control mode in which the above-mentioned assist control is not performed (no-control mode).

[0144] In this modified example, the controller 70 sets the control mode to assist mode when the assist mode switch 91 is ON, and sets the control mode to non-assist mode when the assist mode switch 91 is OFF. In assist mode, the controller 70 sets the control mode to bucket opening / closing mode when the opening / closing mode switch 90 is ON, and sets the control mode to synchronized control mode when the opening / closing mode switch 90 is OFF. The synchronized mode includes power synchronized mode and free synchronized mode. Specifically, these are as follows.

[0145] The assist mode switch 91 is a switch for setting the control mode of the crane 100 to assist mode. When the assist mode switch 91 is turned on by the operator, it inputs an on command signal corresponding to the on operation to the controller 70, and the controller 70 sets the control mode to assist mode. If the assist mode switch 91 is not turned on, the controller 70 does not set the control mode to assist mode, but sets the control mode to another predetermined control mode (for example, non-assist mode).

[0146] The opening / closing mode switch 90 is a switch for setting the control mode of the controller 70 to the bucket opening / closing mode. When the control mode is set to assist mode and an ON operation for the bucket opening / closing mode is given to the opening / closing mode switch 90 by the operator, the opening / closing mode switch 90 inputs an ON command signal corresponding to the ON operation to the controller 70, and the controller 70 sets the control mode to the bucket opening / closing mode. When the control mode is set to assist mode and the ON operation is not given to the opening / closing mode switch 90, the controller 70 sets the control mode to synchronized control mode.

[0147] The controller 70 sets the control mode to one of the following: bucket opening / closing mode, power synchronization mode, free synchronization mode, or non-assist mode, by performing calculation processing as shown in the flowchart in Figure 10, for example.

[0148] The bucket opening / closing mode is a control mode that allows the bucket device 10 to perform operations, including changing the open / closed state of a pair of buckets 13, 13, based on a specific pre-set operation. When the control mode is set to bucket opening / closing mode, the controller 70 performs non-synchronized control such as bucket stationary closing control, bucket stationary opening control, and excavation control, which will be described later.

[0149] When the control mode is set to the power synchronization mode, the controller 70 performs the power synchronization control described later. When the control mode is set to the free synchronization mode, the controller 70 performs the free synchronization control described later.

[0150] The controller 70 includes a computer that includes a processing unit and memory. In the modified example shown in Figure 9, the controller 70 includes a lifting value calculation unit 71, an operation state determination unit 72, a bucket weight calculation unit 73, a wire tension determination unit 74, an assist mode determination unit 75, a target pilot pressure calculation unit 76, and a valve command current value calculation unit 77. Each of these functions is realized by the processing unit executing a control program stored in the memory.

[0151] The lifting height calculation unit 71 calculates the lifting height of the first winch rope R1 and the lifting height of the second winch rope R2, respectively, based on the setting data input from the operator setting device 21 to the controller 70, the detection results input from the drum rotation detectors 81 and 82 to the controller 70, and the luffing angle θ of the luffing member 104 input from the luffing member angle detector 22 to the controller 70.

[0152] The setting data input from the operator setting device 21 to the controller 70 may include, for example, specification data including the length of the luffing member 104, and may further include data relating to the relative position of the first winch drum DR1 with respect to the specific part of the luffing member 104, and data relating to the relative position of the second winch drum DR2 with respect to the specific part of the luffing member 104.

[0153] The operation state determination unit 72 determines the lever operation state for the first winch operation lever 51A and the second winch operation lever 53A, respectively, based on the detection results input to the controller 70 from the first lever input detector 51B and the second lever input detector 53B. Specifically, the operation state determination unit 72 determines, based on the detection results, whether the lever operation state is a winding operation state (rewinding operation state), a lowering operation state (unwinding operation state), or a neutral state.

[0154] The operation state determination unit 72 may determine that the lever operation state is a winding operation state if the amount of winding operation applied to each of the first winch operation lever 51A and the second winch operation lever 53A is equal to or greater than the operation amount threshold. The operation state determination unit 72 may also determine that the lever operation state is a lowering operation state if the amount of unwinding operation applied to each of the first winch operation lever 51A and the second winch operation lever 53A is equal to or greater than the operation amount threshold.

[0155] The operation state determination unit 72 may determine the pedal operation state for the first brake operation pedal 52A and the second brake operation pedal 54A, respectively, based on the detection results input to the controller 70 from the first pedal input detector 52B and the second pedal input detector 54B. Specifically, the operation state determination unit 72 may determine, based on the detection results, whether the pedal operation state is a brake state or a free state.

[0156] The bucket weight calculation unit 73 calculates the weight of the bucket device 10. Specifically, the bucket weight calculation unit 73 may calculate the weight of the bucket device 10 based on the load value detected by the load value detector 94 at the time an operator performs an input operation on the bucket weight setting device (not shown in the figure). The bucket weight setting device may include, for example, a touch panel on a monitor.

[0157] The wire tension determination unit 74 determines whether the bucket device 10 is touching the ground or not based on the load value detected by the load value detector 94 and the bucket weight. For example, the wire tension determination unit 74 may determine that the bucket device 10 is touching the ground if the load value detected by the load value detector 94 at that time is less than or equal to a predetermined first threshold that is less than the bucket weight (for example, less than or equal to 30% of the bucket weight). For example, the wire tension determination unit 74 may determine that the bucket device 10 is not touching the ground if the load value detected by the load value detector 94 at that time is greater than or equal to a predetermined second threshold that is greater than the first threshold (for example, more than or equal to 70% of the bucket weight).

[0158] The assist mode determination unit 75 determines the control mode of the crane 100. Specifically, the assist mode determination unit 75 may determine whether the control mode is bucket opening / closing mode, power synchronization mode, free synchronization mode, or non-assist mode (no control mode) by performing calculation processing as shown in the flowchart of Figure 10, which will be described later.

[0159] The target pilot pressure calculation unit 76 recognizes the current control mode (bucket opening / closing mode, power synchronization mode, free synchronization mode, or non-assist mode) based on the determination result made by the assist mode determination unit 75, and calculates the target pilot pressure to be input to the first control valve 32 and the second control valve 33, respectively, according to the control mode.

[0160] The valve command current value calculation unit 77 calculates command current values ​​to be input to the first dispensing proportional valve 61A, the first retracting proportional valve 61B, the second dispensing proportional valve 63A, and the second retracting proportional valve 63B, respectively, based on the target pilot pressure calculated by the target pilot pressure calculation unit 76. Specifically, for example, the valve command current value calculation unit 77 may calculate the command current values ​​using the target pilot pressure calculated by the target pilot pressure calculation unit 76 and a map representing the relationship between the target pilot pressure and the command current values, as shown in Figure 6, for example. The controller 70 inputs the calculated command current values ​​to the proportional valves 61A, 61B, 63A, and 63B, respectively. The controller 70 may also calculate command current values ​​to be input to various switching valves included in the hydraulic circuit of the crane 100 and input the calculated command current values ​​to the switching valves.

[0161] Figure 10 is a flowchart showing an example of the calculation process performed by the controller 70 in the modified example.

[0162] In step S101, the controller 70 determines whether predetermined bucket opening / closing mode conditions are met. The bucket opening / closing mode conditions are conditions for determining whether or not to set the control mode to bucket opening / closing mode. Specifically, for example, the bucket opening / closing mode conditions may be that the opening / closing mode switch 90 is ON and the luffing operation lever 55A is not operated.

[0163] If the bucket opening / closing mode conditions are met (YES in step S101), specifically, if the opening / closing mode switch 90 is ON and the luffing operation lever is not operated, the controller 70 sets the control mode to the bucket opening / closing mode in step S102. If the bucket opening / closing mode conditions are not met (NO in step S101), the controller 70 performs the process in step S103.

[0164] In step S103, the controller 70 determines whether a predetermined power synchronization mode condition is met. The power synchronization mode condition is a condition for determining whether or not to set the control mode to power synchronization mode. The power synchronization mode condition may be, for example, the condition that the first winch operating lever 51A is being operated.

[0165] If the power synchronization mode condition is met (YES in step S103), specifically, if the first winch operating lever 51A is operated, the controller 70 sets the control mode to power synchronization mode in step S104. If the power synchronization mode condition is not met (NO in step S103), the controller 70 performs the process in step S105.

[0166] In step S105, the controller 70 determines whether a predetermined free-synchronization mode condition is met. The free-synchronization mode condition is a condition for determining whether or not to set the control mode to free-synchronization mode. The free-synchronization mode condition may be, for example, a neutral free mode and a main hoist free operation. Specifically, the crane 100 has a neutral free mode and a neutral brake mode as control modes. In neutral brake mode, even when the brake pedal is released and not pressed, the winch drum remains connected to the power side. That is, the winch drum will not move without lever operation. By pressing the free switch while the brake pedal is pressed in neutral brake mode, the system enters neutral free mode. By releasing the brake pedal, the winch drum is disconnected from the power side, and the drum rotates due to gravity. "Main hoist free operation" refers to a state where the brake pedal is released, and the brake pressure is such that the drum is disconnected from the power side, meaning the winch drum is driven by the brake pedal. This is detected by a pressure sensor that detects pedal pressure.

[0167] If the free tuning mode condition is met (YES in step S105), specifically in neutral free mode and when there is a main winding free operation, the controller 70 sets the control mode to free tuning mode in step S106. If the free tuning mode condition is not met (NO in step S105), the controller 70 sets the control mode to non-assist mode (no control mode) in step S107.

[0168] [Bucket opening / closing mode] Next, we will explain the bucket opening and closing modes.

[0169] When the control mode is set to bucket opening / closing mode, the controller 70 performs non-synchronized control such as bucket stationary closing control, bucket stationary opening control, and excavation control.

[0170] Bucket stationary closing control is a control method used in the bucket opening / closing mode to close the buckets 13, 13 while the bucket device 10 is stationary in the air. In bucket stationary closing control, the second winch operating lever 53A is in the neutral position, and the second brake operating pedal 54A is pressed down, meaning that the second winch drum DR2 is braked to prevent its rotation, and a winding operation is applied to the first winch operating lever 51A. This allows the first winch rope to be wound up without paying out or winding up the second winch rope, and the bucket device 10 can be operated in the closing direction while maintaining its height in the air.

[0171] Bucket stationary opening control is a control method used in the bucket opening / closing mode to open and operate the buckets 13, 13 while the bucket device 10 is stationary in the air. In bucket stationary opening control, the second winch operating lever 53A is in the neutral position, and the second brake operating pedal 54A is pressed down, meaning that the second winch drum DR2 is braked to prevent its rotation. The first brake operating pedal 52A is then operated to reduce (weaken) the first brake force. This allows the first winch rope R1 to be extended and its tension to be released without extending or retracting the second winch rope, enabling the bucket device 10 to be operated in the opening direction while maintaining its height in the air. This aerial opening operation is used, for example, in soil removal operations, such as removing soil or other materials held in the closed bucket device 10 onto a destination (e.g., the bed of a truck).

[0172] Excavation control is the control that causes the bucket device 10 to perform an excavation operation in the bucket opening and closing mode. In excavation control, the second winch drum DR2 is left free, and the first winch rope R1 is wound up with the first winch drum DR1, thereby loosening the tension of the second winch rope R2 and causing the bucket device 10 to perform the action of closing the bucket device 10. As a result, during the process of closing the bucket device 10 in the excavation operation, the bucket device 10 sinks down as the material to be excavated, such as soil, is excavated, allowing more material to be stored inside the bucket device 10.

[0173] [Power synchronization mode] Next, we will explain the power synchronization mode. The power synchronization mode is a mode that synchronizes the operation of the first winch drum DR1 with the operation of the second winch drum DR2.

[0174] When the control mode is set to power synchronization mode, the controller 70 performs power synchronization control such as opening down control, closing down control, opening up control, and closing up control. In power synchronization mode, the controller 70 controls the operation of the first winch drum DR1 and the operation of the second winch drum DR2 based on the first lever operation applied to the first winch operating lever 51A. The power synchronization control and tension synchronization control by the controller 70 are performed when the control mode is set to power synchronization mode. The lifting operation performed by the bucket device 10 is performed, for example, in the closing up control or the opening up control of the power synchronization control.

[0175] Specifically, when the control mode is set to power synchronization mode and an extension operation is applied to the first winch operating lever 51A, the controller 70 performs the following opening-down control or closing-down control. In opening-down control, the controller 70 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 state of the bucket device 10. In closing-down control, the controller 70 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 closed state of the bucket device 10.

[0176] Furthermore, when the control mode is set to power synchronization mode and a winding operation is applied to the first winch operating lever 51A, the controller 70 performs the following opening-up control or closing-up control. In opening-up control, the controller 70 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 state of the bucket device 10. In closing-up control, the controller 70 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 closed state of the bucket device 10.

[0177] [Free tune mode] Next, I will explain the free tuning mode.

[0178] When the control mode is set to free synchronization mode, the controller 70 performs free synchronization control to adjust the first braking force and the second braking force of the first clutch brake 40 and the second clutch brake 40 based on the amount of operation of the first pedal applied to the first brake operation pedal 52A (pedal operation amount).

[0179] The controller 70 adjusts the first brake force and the second brake force. When the control mode is set to free synchronization mode, a first brake operation that reduces the first brake force is applied to the first brake operation pedal 52A, and the bucket device 10 is in the open state, the controller 70 performs the following opening down control. In this opening down control, the controller 70 adjusts the first brake force and the second brake force so that the bucket device 10 descends by its own weight while maintaining the open state of the bucket device 10. Such opening down control performed in response to an operation applied to the brake operation pedal is an example of free synchronization control.

[0180] Furthermore, when the control mode is set to free synchronization mode, a first brake operation that reduces the first brake force is applied to the first brake pedal 52A, and the bucket device 10 is in the closed state, the controller 70 performs the following closing down control. In this closing down control, the controller 70 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. This closing down control, which is performed in response to an operation applied to the brake pedal, is an example of free synchronization control. A first brake operation that reduces the first brake force is, for example, an operation that reduces the amount of pedal operation (depression amount) applied to the first brake pedal 52A.

[0181] The controller 70 may determine the open or closed state of the bucket device 10. That is, the controller 70 may determine whether the bucket device 10 is in an open state or a closed state. The controller 70 may determine the open or closed state of the bucket device 10 based on a first rotation amount ωm and a second rotation amount ωa.

[0182] This disclosure is not limited to the embodiments described above. This disclosure includes, for example, the following forms:

[0183] (A) Regarding the specifications of the crane The crane according to the embodiment shown in Figure 1 does not have a jib and struts, but the specifications of the crane are not limited to those shown in Figure 1. The crane according to this disclosure may be a luffing crane equipped with a jib, front struts and rear struts, or it may be a fixed jib crane equipped with a jib and one strut. Furthermore, the crane according to this disclosure may be a crane equipped with a mast instead of a gantry (for example, a large crane).

[0184] 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.

[0185] (B) Regarding winch ropes and winch drums In the above embodiment, the first winch rope R1 is the opening / closing rope, the second winch rope R2 is the support rope, the first winch drum DR1 is the opening / closing drum, and the second winch drum DR2 is the support drum. However, these configurations may be reversed. That is, the first winch rope R1 may be the support rope, the second winch rope R2 may be the opening / closing rope, the first winch drum DR1 may be the support drum, and the second winch drum may be the opening / closing drum.

[0186] (C) About the synchronization control device In the above embodiment, the synchronization control device 200 is provided on the crane 100, but the synchronization 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 synchronization control device is configured to be able to send and receive information between the synchronization control device and the construction machine via a network such as the internet or a mobile phone network.

[0187] (D) Regarding the operating device The operating device according to the present disclosure may be appropriately selected according to the types of the first and second winches and their driving devices. For example, the lever input detectors 51B and 53B of the first winch operating device 51 and the second winch operating device 53 shown in FIGS. 2 and 3, and the pedal input detectors 52B and 54B of the first brake operating device 52 and the second brake operating device 54 may each be replaced with a device including a remote control valve that outputs a pilot pressure according to an operation and a pressure sensor that detects the pilot pressure. In this case, the proportional valves 61A and 61B may be respectively interposed between the remote control valve of the first winch operating device 51 and a pair of pilot ports of the first control valve, and the proportional valves 63A and 63B may be respectively interposed between the remote control valve of the second winch operating device 53 and a pair of pilot ports of the second control valve 33. Further, the proportional valve 62 may be interposed between the remote control valve of the first brake operating device 52 and the first clutch brake 40, and the proportional valve 64 may be interposed between the remote control valve of the second brake operating device 54 and the second clutch brake 40.

[0188] (E) Regarding the winch The first and second winches according to the present disclosure may be, for example, electric winches. In this case, the hydraulic circuit shown in FIG. 3 can be replaced with an electric circuit (for example, a circuit including an inverter) that drives the electric winch.

[0189] (F) Regarding the filter processing The transfer function K d (z) of the digital filter may be represented, for example, by the following equation (7).

[0190] [Equation] <www.downloadslide.com

[0191] In the above equation (7), "a l " and "b k " are filter coefficients. "a l " is mainly a coefficient related to the filter output, and "bk " are coefficients mainly related to the filter input. These coefficients are determined so that the desired characteristics are obtained in the digital filter. -l " and "z -k Each of these is a delay element.

[0192] The above transfer function K d While there are no particular limitations on the specific calculation method for a digital filter that can realize the characteristics of (z), the direct type of IIR filter can be expressed, for example, by the following equation (8).

[0193]

number

[0194] In equation (8) above, "y" is the filter output (output signal) that is output from the filter, "u" is the filter input (input signal) that is input to the filter, and "t s " is the filter update period (control period). "y(t)" is the filter output at that point in time (the current time), and "y(t-lt s )" is "lt s This is the filter output before the period, and "u(t-kt s )」 is "kt s This is the filter input before the period. Note that when "k=0", "u(t-kt s )" is "u(t)", and represents the filter input at that point in time (the current time). [Explanation of Symbols]

[0195] 10: Bucket device 23: Input device 34: First winch motor 35: Second winch motor 51: First winch operating device 53: Second winch operating device 61A: First dispensing proportional valve 61B: First winding proportional valve 63A: Second proportional valve for dispensing 63B: Second proportional valve for winding 65: First constant horsepower control valve 66: Second constant horsepower control valve 70: Controller 100: Crane 200: Synchronization control device DR1: First winch drum DR2: Second winch drum R1: First winch rope R2: Second winch rope T1: Tension acting on the first winch rope T2: Tension acting on the second winch rope

Claims

1. A synchronization control device for a construction machine comprising: a machine body; a luffing member that can be raised and lowered relative to the machine body; a first winch drum for paying out and reeling in a first winch rope hanging from the luffing member; a second winch drum for paying out and reeling in a second winch rope hanging from the luffing member; and a bucket device to which the first winch rope and the second winch rope are connected, and which can be raised and lowered in accordance with the operation of the first winch drum and the operation of the second winch drum, wherein A synchronization control device comprising a controller capable of selecting either power synchronization control for reducing the deviation between a physical quantity correlated with the amount of the first winch rope unwound and a physical quantity correlated with the amount of the second winch rope unwound when raising the bucket device, or tension synchronization control for reducing the tension deviation, which is the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope when raising the bucket device.

2. The synchronization control device according to claim 1, wherein the controller performs feedback control based on the deviation in the power synchronization control.

3. The construction machine includes a first winch motor, which is a variable displacement hydraulic motor for operating the first winch drum; a second winch motor, which is a variable displacement hydraulic motor for operating the second winch drum; a first constant horsepower control valve for adjusting the capacity of the first winch motor in accordance with the load acting on the first winch motor to keep the output of the first winch motor constant; and a second winch motor for adjusting the capacity of the second winch motor in accordance with the load acting on the second winch motor to keep the output of the second winch motor constant. The system further comprises a second constant horsepower control valve, a first winding proportional valve that outputs pilot pressure for controlling the winding operation of the first winch drum, a second winding proportional valve that outputs pilot pressure for controlling the winding operation of the second winch drum, a first winch operating device that receives a first winding operation to cause the first winch drum to wind the first winch rope, and a second winch operating device that receives a second winding operation to cause the second winch drum to wind the second winch rope. The synchronization control device according to claim 1, wherein the controller inputs the same current command value to the first winding proportional valve and the second winding proportional valve in the tension synchronization control.

4. The aforementioned construction machine further comprises an input device capable of receiving input from an operator, The synchronization control device according to claim 1, wherein the controller selects either the power synchronization control or the tension synchronization control based on the input received by the input device and executes the selected control.

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

6. A synchronization control method for a construction machine comprising: a machine body; a luffing member that can be raised and lowered relative to the machine body; a first winch drum for paying out and reeling in a first winch rope hanging from the luffing member; a second winch drum for paying out and reeling in a second winch rope hanging from the luffing member; and a bucket device to which the first winch rope and the second winch rope are connected, and which can be raised and lowered in accordance with the operation of the first winch drum and the operation of the second winch drum, wherein A synchronization control method comprising the controller selecting either power synchronization control for reducing the deviation between a physical quantity correlated with the amount of the first winch rope unwound and a physical quantity correlated with the amount of the second winch rope unwound when raising the bucket device, or tension synchronization control for reducing the tension deviation, which is the deviation between the tension acting on the first winch rope and the tension acting on the second winch rope when raising the bucket device.

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