Crane remote control system, remote control terminal, and crane

Abstract

To provide a crane remote control system with good operability in remote control.SOLUTION: A remote control system of a crane (100) includes: turn operation units (6, 70) that output turn operation signals for a crane; and a turn drive unit (HC1) that turns the crane based on an output value of the turn operation signal of the crane output from the turn operation unit. The turn operation unit has: a first output unit (6) provided on the crane and outputs a first signal which is a turn operation signal of the crane; and a second output unit (70) capable of being connected to the crane via a communication line and outputting a second signal which is a turn operation signal of the crane. The turn drive unit turns the crane so that a turning speed of the crane relative to an output value of the first signal varies according to a first characteristic (L1), and turns the crane so that the turning speed of the crane relative to an output value of the second signal varies according to a second characteristic (L2) which is different from the first characteristic.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a remote operation system for a crane, a remote operation terminal, and a crane.

Background Art

[0002] As background art in this technical field, for example, Patent Document 1 describes a technique in which an operator operates a remote control device to operate a machine such as a crane.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When remotely operating a large machine such as a crane, the operating feeling may be different from that of operating in the driver's cab or operating by automatic driving (ordinary crane operation). Therefore, when an operator operates a remote control device (remote operation terminal) of a crane with the same feeling as an ordinary crane operation, there may be a sense of discomfort.

[0005] Therefore, an object of the present invention is to provide a remote operation system for a crane, a remote operation terminal, and a crane that have good operability in remote operation.

Means for Solving the Problems

[0006] To achieve the above object, a typical invention of the present invention is a remote control system for a crane, comprising: a slewing operation unit that outputs a slewing operation signal of the crane; and a slewing drive unit that slews the crane based on an output value of the slewing operation signal of the crane output from the slewing operation unit. The slewing operation unit includes: a first output unit provided on the crane that outputs a first signal which is a slewing operation signal of the crane; and a second output unit that can be connected to the crane via a communication line and outputs a second signal which is a slewing operation signal of the crane. The slewing drive unit slews the crane such that the slewing speed of the crane with respect to the output value of the first signal changes according to a first characteristic, and also slews the crane such that the slewing speed of the crane with respect to the output value of the second signal changes according to a second characteristic different from the first characteristic. The maximum slewing speed of the crane with respect to the output value of the second signal is smaller than the maximum slewing speed of the crane with respect to the output value of the first signal, and the same maximum slewing speed is not set for the first output unit and the second output unit It is characterized by the above.

[0007] According to the present invention, in the remote control of a crane, a crane operation with good operability can be performed. In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the crane according to the present invention will be described with reference to the drawings.

[0010] FIG. 1 is a side view of a crane 100 according to an embodiment of the present invention. The crane 100 is a crawler crane and includes a traveling body 101, a slewing body 103 rotatably provided on the traveling body via a slewing ring 102, and a boom 104 pivotally supported on the slewing body 103. The traveling body 101 has a truck frame 101a and crawlers 101b attached to the truck frame 101a.

[0011] The slewing body 103 is provided with a driver's cab 109, and in addition to an engine 107 which is a prime mover, a winch drum 105 which is a winch device and a rear winch drum 106 are mounted. A hoisting rope 105a is wound around the hoisting drum 105, and by driving the hoisting drum 105, the hoisting rope 105a is wound up or paid out, and the hook 110 moves up and down. A luffing rope 106a is wound around the rear winch drum 106, and by driving the rear winch drum 106, the luffing rope 106a is wound up or paid out, and the boom 104 luffs.

[0012] The slewing body 103 is slewing-driven by a slewing hydraulic motor 1 (see FIG. 4) via a slewing ring 102, the hoisting drum 105 is driven by a hoisting hydraulic motor (not shown), and the rear winch drum 106 is driven by a rear winch hydraulic motor (not shown). Although not shown in detail, when assembling the crane 100, the slewing body 103 and the traveling body 101 can be fixed by a slewing lock pin 108 which is an example of a fixing means so that the slewing body 103 does not slew.

[0013] FIG. 2 is a perspective view showing the entire cab 109. As shown in FIG. 2, the cab 109 is provided with a driver's seat 201 on which an operator sits, a right lever group (travel lever, winch operation lever, etc.) 210 that is operated by the operator sitting on the driver's seat 201 with the right hand, a left lever (swing lever) 221 that is operated by the operator sitting on the driver's seat 201 with the left hand, and a wireless communication antenna 50 for communication. Further, a display device 231 is provided at the left front of the driver's seat 201, and various information such as the operating state and warnings of the crane 100 is displayed thereon.

[0014] On the floor of the cab 109, there are provided a hoisting drum brake pedal 251 for braking the hoisting drum 105, a rear drum brake pedal 252 for braking the rear winch drum 106, an accelerator pedal 261 for increasing or decreasing the rotational speed of the engine 107, and a swing brake pedal 262 for braking the swing body 103.

[0015] The left lever, that is, the swing lever 221, is an operating lever for swing-driving the swing body 103 by swinging it in the front-rear direction. As shown in FIG. 3, the swing lever 221 has a gripping portion 221d that is gripped by the operator sitting on the driver's seat 201. The swing lever 221 is provided with an accelerator grip 221a and a swing brake switch 221b.

[0016] The accelerator grip 221a is an operating device for increasing or decreasing the rotational speed of the engine 107 by rotating it clockwise or counterclockwise when viewed from above while the operator holds it with the left hand. The accelerator grip 221a is integrated with the swing lever 221, and the operator can operate the swing lever 221 while operating the accelerator grip 221a with one hand. In this embodiment, in addition to operating the accelerator grip 221a, the rotational speed of the engine 107 can also be increased or decreased by operating the accelerator pedal 261.

[0017] The slewing brake switch 221b is a switch for selecting whether to apply a slewing brake that holds the slewing body 103 so that it does not slew.

[0018] Also, as shown in FIG. 2, a gate lock lever 215 is provided in the driver's cab 109. The gate lock lever 215 is operable vertically between a lock release position that blocks the entrance and exit of the driver's cab 109 and a lock operation position that opens the entrance and exit of the driver's cab 109. The gate lock lever 215 disables all operations of the crane 100 in the lock operation position. That is, when the gate lock lever 215 is in the lock operation position, all operations such as the lifting operation, traveling operation, and slewing operation of the crane 100 become impossible.

[0019] Next, a hydraulic drive circuit for driving the slewing body 103 of the crane 100 will be described. FIG. 4 is a diagram showing a hydraulic circuit HC1 for driving a slewing hydraulic motor 1. As shown in FIG. 4, the hydraulic circuit HC1 is a neutral-free slewing hydraulic circuit that connects a slewing hydraulic pump (hereinafter simply referred to as the hydraulic pump 8) and a slewing hydraulic motor (hereinafter simply referred to as the hydraulic motor 1) with a direction control valve 7.

[0020] The hydraulic circuit (slewing drive unit) HC1 includes a variable displacement type hydraulic pump 8 driven by an engine 107 (see FIG. 1), a hydraulic motor 1 rotated by the pressure oil discharged from the hydraulic pump 8, a slewing brake device 20 that brakes the rotation of the hydraulic motor 1, and a relief valve 9 that defines the maximum pressure of the pressure oil discharged from the hydraulic pump 8. Further, the hydraulic circuit HC1 includes a direction control valve 7 that controls the flow of pressure oil from the hydraulic pump 8 to the hydraulic motor 1, a pilot pump 12 driven by the engine 107, a slewing lever device 6, and a relief valve 11 that defines the maximum pressure of the pilot pressure oil discharged from the pilot pump 12.

[0021] The swing lever device 6 includes a swing lever 221 (see FIG. 4) and pilot valves 6a, 6b connected to the pilot pump 12. The swing lever device (swing operation unit / first output unit) 6 generates an operation pilot pressure (swing operation signal / first signal) for instructing the swing operation of the swing body 103 by the pilot valves 6a, 6b according to the operation direction and operation amount of the swing lever 221, and outputs it to the pilot pressure input parts 7a, 7b of the direction control valve 7, thereby performing a swing operation of the swing body 103.

[0022] Piping lines 30a, 30b through which pressure oil discharged from the hydraulic pump 8 is supplied to the hydraulic motor 1 via the direction control valve 7 are connected. The rotational force of the hydraulic motor 1 is transmitted to the swing ring 102 (see FIG. 1) via a planetary reduction mechanism (not shown).

[0023] The direction control valve 7 is a control valve having a neutral free position (N) and is inserted in the oil passage between the hydraulic pump 8 and the hydraulic motor 1. The position of the spool of the direction control valve 7 is controlled by the operation pilot pressure (pressure of pilot pressure oil) generated by the pilot valves 6a, 6b according to the operation of the swing lever 221 provided in the driver's cab 109.

[0024] When the operator operates the swing lever 221 to the forward rotation side, the operation pilot pressure output from the pilot valve 6a acts on the pilot pressure input part 7a of the direction control valve 7, and the direction control valve 7 switches to the forward rotation position (A) side. As a result, the pressure oil discharged from the hydraulic pump 8 is supplied to the hydraulic motor 1 via the piping line 30b, the hydraulic motor 1 rotates forward, and the swing body 103 swings in the forward direction (for example, left swing).

[0025] When the operator operates the swing lever 221 to the reverse rotation side, the operation pilot pressure output from the pilot valve 6b acts on the pilot pressure input part 7b of the direction control valve 7, and the direction control valve 7 switches to the reverse rotation position (B) side. As a result, the pressure oil discharged from the hydraulic pump 8 is supplied to the hydraulic motor 1 via the piping line 30a, the hydraulic motor 1 rotates in reverse, and the swing body 103 swings in the reverse direction (for example, right swing).

[0026] When the operator returns the swivel lever 221 from the swivel operation position to the neutral position, the direction control valve 7 switches to the neutral free position (N), and the pipeline 30a and the pipeline 30b are in a communicating state. Therefore, the hydraulic motor 1 becomes rotatable under an external force. Accordingly, the swivel body 103 becomes in a free state where it can rotate by inertia. This state is also called neutral free. When it is in the neutral free state, the swivel brake device 20 described later can be operated to generate a braking force on the swivel body 103 to stop the swiveling of the swivel body 103. Also, the swivel body 103 can be stopped by operating the swivel lever 221 to the side opposite to the swiveling direction of the swivel body 103.

[0027] The swivel brake device 20 includes a hydraulic cylinder (hereinafter referred to as the brake release cylinder 2) having a pad 2p that presses against a swivel brake disk (not shown) provided on the output shaft of the hydraulic motor 1, and a swivel brake valve 13 that controls the flow of pressure oil supplied from the pilot pump 12 to the brake release cylinder 2.

[0028] The swivel brake device 20 is a so-called negative brake. When the brake release cylinder 2 communicates with the tank, the pad 2p is pressed against the swivel brake disk (not shown) by the spring force, the swivel brake operates, and a braking force on the swivel body 103 is generated. When a release pressure acts on the brake release cylinder 2, the swivel brake device 20 is released. When the swivel brake device 20 is released, a gap is formed between the swivel brake disk (not shown) and the pad 2p, so that no braking force on the swivel body 103 is generated.

[0029] The swing brake valve 13 is provided between the pilot pump 12 and the brake release cylinder 2. The swing brake valve 13 is an electromagnetic switching valve that allows the flow of pressure oil from the pilot pump 12 to the brake release cylinder 2 in the release position (C) and prohibits the flow of pressure oil from the pilot pump 12 to the brake release cylinder 2 in the operating position (D). When the swing brake valve 13 is switched to the operating position (D), the brake release cylinder 2 communicates with the tank, and the pressure in the oil chamber of the brake release cylinder 2 becomes the tank pressure.

[0030] The hydraulic circuit HC1 includes a gate lock valve 10 provided between the pilot pump 12 and the pilot valves 6a, 6b. The gate lock valve 10 is an electromagnetic switching valve that allows the flow of pressure oil from the pilot pump 12 to the pilot valves 6a, 6b in the communication position (E) and prohibits the flow of pressure oil from the pilot pump 12 to the pilot valves 6a, 6b in the cutoff position (F).

[0031] The pilot pump 12 is connected to the swing brake valve 13 via the gate lock valve 10. When the gate lock valve 10 is switched to the cutoff position (F), even if the swing brake valve 13 is switched to the release position (C), no pressure oil is supplied to the brake release cylinder 2, so the swing brake device 20 is in the operating state (i.e., the state where braking force is generated). That is, when the gate lock valve 10 is switched to the cutoff position (F), the operation of the swing lever 221 becomes impossible. The swing brake device 20 is released when the gate lock valve 10 is switched to the communication position (E) and the swing brake valve 13 is switched to the release position (C).

[0032] Furthermore, in the present embodiment, the pilot pump 12 and the pilot pressure input portions 7a are connected via a branch pipeline 40a, and a solenoid valve 41a and a high-pressure selection shuttle valve 42a are provided in the branch pipeline 40a. Similarly, the pilot pump 12 and the pilot pressure input portion 7b are connected via a branch pipeline 40b, and a solenoid valve 41b and a high-pressure selection shuttle valve 42b are provided in the branch pipeline 40b.

[0033] Since the solenoid valves 41a and 41b are normally closed (non-excited state), the pilot pressure oil discharged from the pilot pump 12 is not supplied to the pilot pressure input portions 7a and 7b of the direction control valve 7. On the other hand, when the solenoid valves 41a and 41b are excited and the solenoid valves 41a and 41b open, the pilot pressure oil discharged from the pilot pump 12 is input to the high-pressure selection shuttle valves 42a and 42b as the operating pilot pressure. Then, the high-pressure side operating pilot pressure selected by the high-pressure selection shuttle valves 42a and 42b is input to the pilot pressure input portions 7a and 7b of the direction control valve 7.

[0034] As described above, since the solenoid valves 41a and 41b are normally closed, the direction control valve 7 usually switches only by operating the swing lever 221. However, when the solenoid valves 41a and 41b open according to a command from a remote operation terminal 70 described later, the direction control valve 7 can be switched without operating the swing lever 221. That is, in the present embodiment, the rotational drive of the hydraulic motor 1 (the swing operation of the crane 100) can be performed not only by operating the swing lever 221 but also by a command from the remote operation terminal 70.

[0035] Also, as shown in FIG. 4, the crane 100 is provided with a controller 3. The controller 3 includes an arithmetic processing unit having a CPU, a ROM and a RAM which are storage devices, and other peripheral circuits. The controller 3 is a control device that controls each part of the crane 100 based on signals from various sensors. The controller 3 is provided in the cab 109 and can perform wireless communication with the remote operation terminal 70 via the wireless communication antenna 50. Of course, the controller 3 and the remote operation terminal 70 may be connected via a wired communication line, and the type of the communication line is not particularly limited. For example, in the case of wireless communication, it may be wifi communication, Bluetooth (registered trademark) communication, or any other method.

[0036] The controller 3 is electrically connected to the slewing brake valve 13 and the gate lock valve 10. The controller 3 is electrically connected to a slewing brake switch 221b provided on the slewing lever 221, and based on a signal from the slewing brake switch 221b, switches the slewing brake valve 13 to the release position (C) or the operating position (D). Further, the controller 3 switches the gate lock valve 10 to the communication position (E) or the cutoff position (F) based on the operation of a gate lock lever 215 (see FIG. 2) provided in the cab 109.

[0037] More specifically, when the slewing brake switch 221b is operated to the off (closed) position, current is supplied from the power source (not shown) of the controller 3 to the solenoid of the slewing brake valve 13, and the solenoid is excited, whereby the slewing brake valve 13 is switched to the release position (C). When the slewing brake switch 221b is operated to the on (open) position, the supply of current from the power source (not shown) of the controller 3 to the solenoid of the slewing brake valve 13 is cut off, and the solenoid is demagnetized, whereby the slewing brake valve 13 is switched to the operating position (D) by the spring force.

[0038] When the gate lock lever 215 is operated to the unlock position, current is supplied from the power supply (not shown) of the controller 3 to the solenoid of the gate lock valve 10, and the solenoid is excited, so that the gate lock valve 10 is switched to the communication position (E). When the gate lock lever 215 is operated to the lock operation position, the supply of current from the power supply (not shown) of the controller 3 to the solenoid of the gate lock valve 10 is cut off, and the solenoid is demagnetized (de-excited), so that the gate lock valve 10 is switched to the shut-off position (F) by the spring force.

[0039] Although not shown in FIG. 4, the gate lock valve 10 is also provided between the pilot pump 12 and the right lever group 210. Therefore, in a state where the gate lock lever 215 is in the lock operation position, all operations such as the lifting operation, traveling operation, and slewing operation of the crane 100 become impossible. That is, in the present embodiment, when the gate lock valve 10 is switched to the shut-off position (F) by the controller 3, all operations of the crane 100 stop.

[0040] Next, a remote operation terminal 70 that communicates with the controller 3 and issues a command for remote operation of the crane 100 will be described. FIG. 5 is an external configuration diagram of the remote operation terminal 70, and FIG. 6 is an internal configuration diagram (block diagram) of the remote operation terminal 70.

[0041] As shown in FIG. 5, the remote operation terminal (slewing operation unit / second output unit) 70 has a wireless communication antenna 51, and transmits various signals (commands) to the controller 3 via the wireless communication antenna 51. Although not shown, the remote operation terminal 70 includes an arithmetic processing device having a CPU, a ROM and a RAM which are storage devices, and other peripheral circuits.

[0042] The remote operation terminal 70 is formed in a box shape, and on its surface, there are a swing brake switch 71, a power switch 72, an engine emergency stop switch 73, a horn switch 74, a swing operation dial 75, a hydraulic pump flow rate adjustment dial 76, an accelerator adjustment dial 77, and a mode setting switch 78. Here, switches 71 to 74 are toggle switches, and the mode setting switch 78 is a slide switch, but the type of switch is not limited. Also, dials 75 to 77 are configured to be able to adjust the operation amount by rotation, but a configuration that can adjust the operation amount by sliding instead of a dial may be used, or one having other adjustment functions may be used.

[0043] The swing brake switch 71 is for operating the swing brake device 20 and has the same function as the swing brake switch 221b provided on the swing lever 221.

[0044] The power switch 72 is a switch for turning on / off the power of the remote operation terminal 70. When the power switch 72 is on, the gate lock valve 10 switches to the communication position (E). When the power switch 72 is off, the gate lock valve 10 switches to the cutoff position (F).

[0045] The engine emergency stop switch 73 is a switch for stopping the engine 107 in an emergency.

[0046] The horn switch 74 is a switch for emitting a warning sound. When the horn switch 74 is turned on, a warning sound is emitted from the speaker provided on the crane 100. Note that a speaker may be mounted on the remote operation terminal 70.

[0047] The swing operation dial 75 is for performing the swing operation of the swing body 103 and is a dial that turns left for left swing and right for right swing. The swing speed of the swing body 103 changes according to the operation amount (rotation amount) of the swing operation dial 75. The change in the swing speed follows the swing characteristics L2 and L3 (see FIG. 7) described later.

[0048] The hydraulic pump flow rate adjustment dial 76 is a dial for adjusting the pump swash plate angle (for example, the swash plate tilt angle) of the hydraulic pump 8. The pump swash plate angle of the hydraulic pump 8 is changed according to the operation amount of the hydraulic pump flow rate adjustment dial 76.

[0049] The accelerator adjustment dial 77 is a dial for increasing or decreasing the rotational speed of the engine 107, and has the same function as the accelerator grip 221a provided on the turning lever 221.

[0050] The mode setting switch 78 is a switch for setting the turning mode (turning characteristics) of the crane 100. When it is slid to the left, the remote normal mode is set, and when it is slid to the right, the low speed mode is set. The remote normal mode and the low speed mode are modes in which the turning speed (change rate) of the slewing body 103 with respect to the operation amount of the turning operation dial 75 is different from each other (details will be described later).

[0051] Also, as shown in FIG. 6, the remote operation terminal 70 includes an input unit 81, a processing unit 82, a first-order lag processing unit 86, and an output unit 87.

[0052] The input unit 81 receives operation signals from the above-described turning brake switch 71, power switch 72, engine emergency stop switch 73, horn switch 74, turning operation dial 75, hydraulic pump flow rate adjustment dial 76, accelerator adjustment dial 77, and mode setting switch 78.

[0053] The processing unit 82 includes a mode determination unit 83, a current command value determination unit 84, and a current command value table 85. The mode determination unit 83 determines whether it is the remote normal mode or the low speed mode based on the operation signal from the mode setting switch 78. The current command value table 85 stores in advance a remote normal mode table 85a corresponding to the remote normal mode and a low speed mode table 85b corresponding to the low speed mode.

[0054] The table 85a for the remote normal mode is a table that defines the current command values for the solenoid valves 41a and 41b with respect to the operation amount of the turning operation dial 75 so as to achieve the turning speed of the crane 100 (the slewing body 103) according to the turning characteristic L2 described later.

[0055] The table 85b for the low-speed mode is a table that defines the current command values for the solenoid valves 41a and 41b with respect to the operation amount of the turning operation dial 75 so as to achieve the turning speed of the crane 100 according to the turning characteristic L3 described later.

[0056] The current command value determination unit 84 refers to the tables 85a and 85b corresponding to the turning mode determined by the mode determination unit 83, and determines the current command values to be output to the solenoid valves 41a and 41b.

[0057] The first-order lag processing unit 86 applies a first-order lag filter to the signal of the current command value determined by the current command value determination unit 84, and outputs the signal of the first-order lag processed current command value to the output unit 87 (see FIG. 9). In this embodiment, for example, a first-order lag filter with a time constant of 1.5 seconds can be used.

[0058] The output unit (second output unit) 87 transmits the signal of the current command value (turning operation signal / second signal, third signal) that has been first-order lag processed by the first-order lag processing unit 86 to the controller 3 via the wireless communication antenna 51. Of course, the output unit 87 also transmits various operation signals received by the input unit 81 to the controller 3. Note that the signal of the current command value corresponding to the remote normal mode corresponds to the "second signal" of the present invention, and the signal of the current command value corresponding to the low-speed mode corresponds to the "third signal" of the present invention.

[0059] The controller 3 that has received the signal of the current command value from the remote operation terminal 70 energizes either the solenoid valve 41a or the solenoid valve 41b based on the operation direction of the swivel operation dial 75, and controls the solenoid valves 41a and 41b to a predetermined opening degree according to the current command value. Then, the operation pilot pressure corresponding to the opening degrees of the solenoid valves 41a and 41b is input to the pilot pressure input parts 7a and 7b of the direction control valve 7, and the direction control valve 7 switches to the forward rotation position (A) or the reverse rotation position (B). Thus, the swivel body 103 can swivel at a predetermined swivel speed according to the operation of the swivel operation dial 75.

[0060] Next, the swivel characteristics of the crane 100 according to the swivel mode will be described. FIG. 7 is a diagram showing the swivel characteristics of the crane 100. In FIG. 7, the horizontal axis represents the operation amount of the swivel operation dial 75 or the swivel lever 221, and the vertical axis represents the operation pilot pressure input to the pilot pressure input parts 7a and 7b of the direction control valve 7. In the figure, the right side from the center of the horizontal axis shows the swivel characteristics during the right swivel of the crane 100, and the left side shows the swivel characteristics during the left swivel of the crane 100. Since the swivel characteristics are the same for the left swivel and the right swivel, in the following description, the swivel characteristics during the right swivel will be described, and the description of the swivel characteristics during the left swivel will be omitted.

[0061] Note that since there is a correlative relationship between the operation pilot pressure and the swivel speed of the crane 100 (swivel body 103), the relationship between the operation pilot pressure with respect to the operation amount of the swivel operation dial 75 is equal to the relationship between the swivel speed with respect to the operation amount of the swivel operation dial 75. Therefore, the operation pilot pressure on the vertical axis is synonymous with the swivel speed of the crane 100. That is to say, it can also be said that FIG. 7 shows the relationship between the swivel speed of the crane 100 with respect to the operation amount of the swivel operation dial 75 or the swivel lever 221.

[0062] FIG. 7 shows three turning characteristics L1, L2, and L3. In FIG. 7, the solid line represents the turning characteristic L1 (first characteristic) during normal operation of the crane 100 (during operation by operating the turning lever 221), the one-dot chain line represents the turning characteristic L2 (second characteristic) when the turning mode is set to the remote normal mode, and the two-dot chain line represents the turning characteristic L3 (third characteristic) when the turning mode is set to the low-speed mode.

[0063] The turning characteristic L1 has a characteristic that the operating pilot pressure (turning speed) increases linearly in proportion to the operation amount of the turning lever 221. The range of the turning lever 221 from the neutral position to the operation amount S11 is the play portion, and the slewing body 103 does not turn even if the turning lever 221 is operated. In the range where the turning lever 221 is from the operation amount S11 to the maximum operation amount S13, as the operation amount of the turning lever 221 increases, the operating pilot pressure increases linearly from zero to P1. In other words, the turning speed of the slewing body 103 increases linearly from zero to the turning speed V1 in response to the operation of the turning lever 221. Note that the turning characteristic L1 (first characteristic) corresponds to the turning operation used in normal lifting operations.

[0064] The turning characteristic L2 has a characteristic in which the change rate of the turning speed of the turning body 103 changes in two stages with respect to the operation amount of the turning operation dial 75. Since the range of the turning operation dial 75 from zero (neutral position) to S11 is the play part, the turning body 103 does not turn even if the turning operation dial 75 is operated. When the operation amount of the turning operation dial 75 reaches S11, the operation pilot pressure becomes P5 and the turning speed becomes V5. That is, when the operator operates the turning operation dial 75 from the neutral position to S11, the turning body 103 starts turning at the speed V5. And in the range where the operation amount of the turning operation dial 75 is from S11 to S12 (predetermined value), as the operation amount increases, the operation pilot pressure (turning speed) increases with the first slope, and when the operation amount reaches S12, the operation pilot pressure becomes P3 (turning speed becomes V3). Also, in the range where the operation amount of the turning operation dial 75 is from S12 to S13, as the operation amount increases, the operation pilot pressure (turning speed) increases with the second slope. And when the operation amount of the turning operation dial 75 reaches S13 (maximum), the operation pilot pressure becomes P2 (turning speed becomes V2).

[0065] Here, the first slope is gentler than the second slope. That is, the change rate of the turning speed of the turning body 103 in the range from S11 to S12 (the first half of the operation) is smaller than the change rate of the turning speed of the turning body 103 in the range from S12 to S13 (the second half of the operation). Therefore, when the turning body 103 turns according to the turning characteristic L2, in the range where the operation amount of the turning operation dial 75 is from S11 to S12, the turning body 103 turns slowly at the turning speed corresponding to the first slope, and in the range where the operation amount of the turning operation dial 75 is from S12 to S13, it turns a little faster at the turning speed corresponding to the second slope.

[0066] The turning characteristic L3 has the characteristic that the change rate of the turning speed of the turning body 103 is constant with respect to the operation amount of the turning operation dial 75. Since the range of the turning operation dial 75 from zero (neutral position) to S11 is the play part, the turning body 103 does not turn even if the turning operation dial 75 is operated. When the operation amount of the turning operation dial 75 reaches S11, the operation pilot pressure becomes P5 and the turning speed becomes V5. Then, in the range where the operation amount of the turning operation dial 75 is from S11 to S13 (maximum), as the operation amount increases, the operation pilot pressure (turning speed) linearly increases with the third slope. When the operation amount reaches S13 (maximum), the operation pilot pressure becomes P4 (turning speed becomes V4).

[0067] Here, the differences between the turning characteristics L1, L2, and L3 will be described. The maximum turning speed of the turning body 103 in the turning characteristic L1 is the largest among the three turning characteristics L1, L2, and L3. Next, the maximum turning speed of the turning characteristic L2 is large, and the maximum turning speed of the turning characteristic L3 is the smallest. That is, the turning speeds are V1 > V2 > V4. Therefore, it is not possible to turn the turning body 103 at a turning speed greater than V2 using the remote operation terminal 70.

[0068] The turning characteristics L2 and L3 are the characteristics applied when turning the turning body 103 by the remote operation terminal 70. The maximum turning speed of the turning body 103 is greater for the turning characteristic L2 than for the turning characteristic L3 (turning speed V2 > V3). And throughout the entire range of the operation amount of the turning operation dial 75, the turning speed of the turning characteristic L2 is greater than that of the turning characteristic L3. Therefore, when turning by the remote operation terminal 70, the turning characteristic L2 (remote normal mode) can turn the turning body 103 at a higher speed than the turning characteristic L3 (very slow mode).

[0069] Also, the change rate (slope) of the turning speed of the turning characteristic L2 is greater than that of the turning characteristic L3. Therefore, when the operator rotates the turning operation dial 75 to a predetermined position, the turning body 103 turns more slowly in the very slow mode than in the remote normal mode.

[0070] Next, the control of the remote operation by the remote operation terminal 70 will be described. FIG. 8 is a flowchart showing the procedure of the control process of the turning operation of the crane 100 by the remote operation terminal 70. The process shown in FIG. 8 starts when the power switch 72 of the remote operation terminal 70 is turned on, and is repeatedly executed at a predetermined cycle (for example, every several tens of milliseconds).

[0071] As shown in FIG. 8, the input unit 81 acquires the operation amount of the turning operation dial 75 (S1). Next, the mode determination unit 83 determines whether the turning mode set by the mode setting switch 78 is the low-speed mode (S2). When the mode determination unit 83 determines that it is the low-speed mode (S2 / Yes), the current command value determination unit 84 refers to the low-speed mode table 85b to determine the current command values of the solenoid valves 41a and 41b (S3), and the output unit 87 transmits a signal of the current command value to the controller 3 via the wireless communication antenna 51 (S4). In this case, the processing by the first-order lag processing unit 86 is not performed.

[0072] The controller 3 receives the signal of the current command value via the wireless communication antenna 50, and excites the solenoid valves 41a and 41b based on the received current command value. In this way, the turning operation of the crane 100 based on the operation amount and the operation direction of the turning operation dial 75 of the remote operation terminal 70 is performed. At this time, the revolving body 103 revolves at a revolving speed according to the revolving characteristic L3 corresponding to the low-speed mode.

[0073] On the other hand, when the mode determination unit 83 determines in S2 that it is not in the very low speed mode (S2 / No), the current command value determination unit 84 refers to the remote normal mode table 85a to determine the current command values for the solenoid valves 41a and 41b (S5), and outputs a signal of the current command value to the first-order lag processing unit 86. Then, the first-order lag processing unit 86 determines whether or not the change rate of the operation amount of the turning operation dial 75 is equal to or greater than the allowable value (S6). When the change rate of the operation amount of the turning operation dial 75 is equal to or greater than the allowable value (S6 / Yes), that is, when the operator suddenly operates the turning operation dial 75, the first-order lag processing unit 86 performs a first-order lag process on the signal of the current command value output from the current command value determination unit 84 (S7). Thereafter, the output unit 87 transmits the signal of the current command value that has been first-order lag processed to the controller 3 via the wireless communication antenna 51 (S8).

[0074] On the other hand, when the change rate of the operation amount of the turning operation dial 75 is less than the allowable value (S6 / No), the output unit 87 transmits a signal of the current command value to the controller 3 via the wireless communication antenna 51 (S8). In this case, the process by the first-order lag processing unit 86 is not performed.

[0075] The controller 3 receives the signal of the current command value via the wireless communication antenna 50, and excites the solenoid valves 41a and 41b based on the received current command value. In this case, the revolving body 103 revolves at a revolving speed according to the revolving characteristic L2 corresponding to the remote normal mode.

[0076] Here, the first-order lag process of S7 will be described in detail with reference to FIG. 9. FIG. 9 is an explanatory diagram of the first-order lag process and is a timing chart showing the rise / fall of the output signal of the current command value. As shown in FIG. 9, when the operator suddenly operates the swing operation dial 75 at time t1, the output signal of the current command value suddenly rises at the timing of time t1. Then, when the operator suddenly returns the swing operation dial 75 to its original state at time t3, the output signal of the current command value suddenly falls at the timing of time t3 (output). On the other hand, when first-order lag control is applied to the output signal, the output signal gradually rises from time t1 to time t2, and the output signal gradually falls from time t3 to time t4 (first-order lag control).

[0077] In this way, by the first-order lag processing unit 86 performing a first-order lag process (filter process) on the output signal, even when the swing operation dial 75 is suddenly operated, the swing body 103 operates with a predetermined delay, so that a sudden change (acceleration / deceleration) in the swing speed of the swing body 103 can be prevented.

[0078] As described above, according to the present embodiment, the following operational effects are achieved.

[0079] When the crane 100 is swing-operated by the remote operation terminal 70, the swing speed will follow the swing characteristics L2 and L3. Therefore, the crane can be remotely operated in a feeling similar to normal crane operation. More specifically, the change rate of the swing speed in the swing characteristics L2 and L3 is smaller than the change rate of the swing speed in the swing characteristics L1. Therefore, even if the swing operation dial 75 and the swing lever 221 are operated by the same operation amount, the increase in the swing speed of the swing operation dial 75 is gentler. Since the swing operation dial 75 is small, if the swing speed suddenly increases with just a little operation, it will feel different from normal crane operation, and the operator will feel a sense of discomfort in the operability. In particular, in the swing operation of the crane, this sense of discomfort is prominent. However, by controlling the swing speed according to the swing characteristics L2 and L3 as in the present embodiment, the crane 100 can be remotely operated in a feeling similar to normal crane operation.

[0080] In other words, when remotely operating the crane, the operator cannot feel the slewing behavior of the crane. Therefore, if the slewing characteristics during remote operation are made the same as those during operation in the operator's cab 109, the operator will feel uncomfortable with the crane operation. In this regard, in the present embodiment, when performing remote operation, the slewing operation of the crane can be performed according to slewing characteristics L2 and L3 different from the slewing characteristic L1 during normal operation, so the operability when remotely operating the crane is improved.

[0081] Also, in remote operation, since the slewing speed is slow in the initial stage when the slewing body 103 starts to slew, even if the operator does not sensuously feel the behavior of the crane 100 in the initial slewing stage, it is easy to visually understand that it is slewing.

[0082] Also, since the change rate of the slewing speed of the slewing characteristic L2 changes in two stages according to the range of the operation amount of the slewing operation dial 75, it is convenient for the operator to use in remote operation. Moreover, the working efficiency of remote operation is also good. When it is desired to quickly move the slewing body 103 during slewing, if the operation amount of the slewing operation dial 75 is increased, the slewing speed can be quickly increased. Therefore, the working efficiency is enhanced.

[0083] Also, since the slewing characteristic L3 slews the slewing body 103 at a lower speed than the slewing characteristic L2, it is suitable when it is desired to slowly slew the slewing body 103. For example, as will be described later, when assembling the crane 100 on site, there is a step of fixing the slewing body 103 to the traveling body 101 with a slewing lock pin 108 (see FIG. 1). In this step, when slewing the slewing body 103 in the slewing characteristic L3 (very low speed mode), it becomes easier to align for the insertion of the slewing lock pin 108, so the workability is improved.

[0084] Also, even when the slewing operation dial 75 is suddenly operated, since the primary delay processing unit 86 causes a delay in the output signal, the slewing body 103 does not suddenly slew following the operation of the slewing operation dial 75. Thus, the operability and safety are improved.

[0085] In addition, since the maximum turning speeds of the turning characteristics L2 and L3 are smaller than the maximum turning speed of the turning characteristic L1, when the remote operation terminal 70 is used for operation, the crane 100 can be turned slowly. Therefore, in the process of assembling the crane 100 on-site, work can be performed more safely. Also, in the assembly operations that require remote operation, there is no need to increase the speed compared to normal crane operations. Therefore, by operating using the remote operation terminal 70 with the turning characteristics L2 and L3 set as in this embodiment, there is also an effect of preventing the slewing body 103 from turning too fast.

[0086] Here, the assembly process of the crane 100 (mainly the process of attaching the crawler 101b to the truck frame 101a of the traveling body 101) will be specifically described.

[0087] (Step 1) Transport the slewing body 103 of the crane 100 and the truck frame 101a of the traveling body 101 (hereinafter referred to as the main body) to a predetermined position by a trailer.

[0088] (Step 2) The operator boards the cab 109 and starts the engine 107. When a start switch for the engine 107 is provided on the remote operation terminal 70, the engine 107 may be started by the remote operation terminal 70.

[0089] (Step 3) The operator jacks up the main body, lifts it from the trailer's gantry, and moves the trailer.

[0090] (Step 4) In order for the operator to attach the crawler 101b to the truck frame 101a of the traveling body 101, the operator operates the slewing operation dial 75 of the remote control terminal 70 to slowly slew the slewing body 103 relative to the traveling body 101 to a predetermined angle (for example, 90 degrees). At this time, it is advisable to set it to the remote normal mode (slewing characteristic L2). Depending on the model, in this step, the crawler 101b may be suspended and slewed by an auxiliary lifting device or the like attached to the lower part of the boom 104 of the crane 100, slowly moved close to the truck frame 101a, and then proceed to Step 6.

[0091] (Step 5) In order for the operator to insert the slewing lock pin 108, the operator slowly slews the slewing body 103 until it reaches a predetermined position. At this time, it is advisable to set it to the very low speed mode (slewing characteristic L3). When the alignment between the slewing body 103 and the traveling body 101 is achieved, insert the slewing lock pin 108 to fix the slewing body 103 and the traveling body 101. Then, stop the engine 107. The engine 107 may be stopped inside the cab 109, or may be stopped by the engine emergency stop switch 73 of the remote control terminal 70.

[0092] (Step 6) Once the slewing lock pin 108 is attached, the operator attaches the crawler 101b to the truck frame 101a. Thus, the assembly work of attaching the crawler 101b to the truck frame 101a is completed.

[0093] In such an assembly process, since the crane 100 can be slewed by operating the remote control terminal 70, the assembly can be carried out with good workability. When slewing the slewing body 103 to a predetermined angle, setting it to the remote normal mode enables the slewing body 103 to be slewed quickly, thus improving workability. Also, when inserting the slewing lock pin 108, the slewing body 103 can be slewed at a very low speed in the very low speed mode, so the insertion work of the slewing lock pin 108 is simple. In this way, by appropriately setting the mode setting switch 78 to perform the assembly work, the work efficiency can be improved.

[0094] (Reference to Other Embodiments) Note that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. All technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments are illustrative examples. Those skilled in the art can realize various alternative examples, modified examples, variations, or improved examples from the content disclosed in this specification, and these are included in the technical scope described in the appended claims.

[0095] For example, in the above-described embodiment, a configuration in which two turning modes (turning characteristics), i.e., the remote normal mode and the slow speed mode, are set at the remote operation terminal 70 is illustrated. However, the number of configurable turning modes is not limited to two. The number of configurable turning modes may be one, or three or more. When the number of turning modes is one, the mode setting switch 78 is not necessary, and the current command value table may also be one.

[0096] Also, in the turning characteristic L2, a configuration in which the change rate of the turning speed changes in two stages is illustrated. However, a configuration in which the change rate does not change, or a configuration in which the change rate changes in three or more stages may also be used. Also, in the turning characteristic L3, the change rate of the turning speed may change in a plurality of stages.

[0097] Also, in the above-described embodiment, a configuration in which a current command value corresponding to the turning mode is transmitted from the remote operation terminal 70 to the controller 3, and the controller 3 controls the solenoid valves 41, 41b according to the received current command value is illustrated. However, instead of this configuration, a configuration in which the controller 3 determines the current command value for the solenoid valves 41a, 41b and controls the solenoid valves 41a, 41b may be used. Specifically, the remote operation terminal 70 includes only the functions of the input unit 81 and the output unit 87, and the controller 3 includes the processing unit 82 and the first-order lag processing unit 86. Then, the controller 3 determines the current command value with reference to the current command value table 85 based on the information on the turning mode transmitted from the remote operation terminal 70 and the information on the operation amount of the turning operation dial 75, and controls the solenoid valves 41a, 41b based on the determination.

[0098] Also, when there is one turning mode, the controller 3 may set a flag based on an input signal from the remote operation terminal 70, and when there is a flag, the revolving body 103 may be revolved with turning characteristics different from those of the normal crane 100 during turning operation.

[0099] Also, the turning lever device 6 may be configured by an electric turning lever, and may generate and output an electric signal (first signal) according to the operation direction and operation amount of the electric turning lever. For example, FIG. 10 is a hydraulic circuit diagram for driving a turning hydraulic motor when using an electric turning lever. As shown in FIG. 10, when the electric turning lever 206 and the controller 3 are electrically connected and the controller 3 outputs an excitation signal to the input parts 207a, 207b of the electromagnetic direction control valve 207 according to the operation of the turning lever 206, the same operational effects as those of the above-described embodiment can be obtained. Further, in the case of automatic operation in which the controller 3 automatically generates and outputs an electric signal to perform a turning operation, the controller 3 functions as a turning lever device (turning operation part) and turns according to the first characteristics.

[0100] Also, the first-order lag processing unit 86 may be provided as necessary. When the first-order lag processing unit 86 is not provided, the output unit 87 may output the signal (second signal, third signal) of the current command value determined by the current command value determination unit 84 to the controller 3 as it is.

[0101] Also, as an example of the crane, a crawler crane has been exemplified, but the present invention is not limited thereto, and in addition to other mobile cranes such as a wheel crane, a truck crane, a rough terrain crane, and an all terrain crane, it can be applied to all cranes such as a tower crane, a ceiling crane, a jib crane, a retractable crane, a stacker crane, a gantry crane, a unloader, and a foundation machine such as an earth drill.

Explanation of Reference Numerals

[0102] 1 Turning hydraulic motor 3 Controller 6 Swing Lever Device (Swing Operation Section / First Output Section) 6a, 6b Pilot Valves (First Output Section) 7 Direction Control Valve 8 Swing Hydraulic Pump 10 Gate Lock Valve 12 Pilot Pump 13 Swing Brake Valve 20 Swing Brake Device 50 Wireless Communication Antenna 51 Wireless Communication Antenna 70 Remote Operation Terminal (Swing Operation Section / Second Output Section) 71 Swing Brake Switch 72 Power Switch 73 Engine Emergency Stop Switch 74 Horn Switch 75 Swing Operation Dial 76 Hydraulic Pump Flow Rate Adjustment Dial 77 Accelerator Adjustment Dial 78 Mode Setting Switch 81 Input Section 82 Processing Section 83 Mode Judgment Section 84 Current Command Value Determination Section 85 Current Command Value Table 85a Table for Remote Normal Mode 85b Table for Micro Speed Mode 86 First-Order Lag Processing Section 87 Output Section (Second Output Section) 100 Crane 101 Traveling Body 102 Swing Wheel 103 Swing Body 104 Boom 105 Hoisting Drum (Winch Device) 106 Rear Winch Drum (Winch Device) 107 Engine 108 Swing Lock Pin 109 Driver's Cab 110 Hook 215 Gate Lock Lever 221 Swing Lever 221a Accelerator grip 221b Steering brake switch 221c Touch sensor 221d Gripping part 231 Display device 251 Hoisting drum brake pedal 252 Rear drum brake pedal 261 Accelerator pedal 262 Steering brake pedal HC1 Hydraulic circuit (steering drive unit) L1 First characteristic L2 Second characteristic L3 Third characteristic

Claims

1. A remote control system for a crane, comprising: A slewing operation unit that outputs a slewing operation signal for the crane; A slewing drive unit that slews the crane based on an output value of the slewing operation signal for the crane output from the slewing operation unit, The slewing operation unit includes: A first output unit provided on the crane that outputs a first signal which is a slewing operation signal for the crane; A second output unit that can be connected to the crane via a communication line and outputs a second signal which is a slewing operation signal for the crane, The slewing drive unit includes: Slewing the crane such that the slewing speed of the crane with respect to the output value of the first signal changes according to a first characteristic; Slewing the crane such that the slewing speed of the crane with respect to the output value of the second signal changes according to a second characteristic different from the first characteristic; A remote control system for a crane, characterized in that the maximum slewing speed of the crane with respect to the output value of the second signal is smaller than the maximum slewing speed of the crane with respect to the output value of the first signal, and the maximum slewing speed is not set to be the same by the first output unit and the second output unit.

2. In the remote control system for a crane according to Claim 1, A remote control system for a crane, characterized in that the magnitude relationship of the slewing speed of the crane is reversed between the second characteristic and the first characteristic with a predetermined value in the range of the output value of the first signal or the second signal as a boundary.

3. In the remote control system for a crane according to Claim 2, A remote control system for a crane, characterized in that the change rate of the slewing speed of the crane in the second characteristic includes a part where it is larger when the range of the output value of the second signal exceeds a predetermined value than when it is below the predetermined value.

4. In the remote control system for a crane according to any one of Claims 1 to 3, The second output unit outputs a third signal which is a slewing operation signal for the crane, A remote control system for a crane, characterized in that the slewing drive unit slews the crane such that the slewing speed of the crane with respect to the output value of the third signal changes according to a third characteristic different from the second characteristic.

5. In the remote control system for a crane according to Claim 4, A remote control system for a crane, characterized in that the third characteristic has a smaller change rate of the slewing speed of the crane compared to the second characteristic.

6. In the remote operation system of a crane according to claim 4 or 5, The third characteristic is that the turning speed of the crane with respect to the output value of the turning operation signal of the crane is smaller than that of the second characteristic, and the remote operation system of the crane is characterized in that.

7. In the remote operation system of a crane according to any one of claims 1 to 6, The remote operation system of a crane is characterized in that the turning speed of the crane operates with a predetermined delay with respect to the output of the turning operation signal of the crane from the second output unit.

8. A remote operation terminal used in the remote operation system of a crane according to any one of claims 1 to 7, and having the second output unit.

9. A crane, Comprising a turning drive unit that turns the crane so that the turning speed changes according to a first characteristic based on an operation of an operator on the crane or an instruction of a controller mounted on the crane, The turning drive unit turns the crane so that the turning speed changes according to a second characteristic different from the first characteristic based on an instruction from a remote operation terminal that can be connected via a communication line from outside the crane, The maximum turning speed of the crane in the second characteristic is smaller than the maximum turning speed of the crane in the first characteristic, and the crane is characterized in that the same maximum turning speed is not set between the first characteristic and the second characteristic.

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