JP7699452B2 - Remote operation system for crane, remote operation terminal, and crane - Google Patents

Description

The present invention relates to a crane remote control system, a remote control terminal, and a crane.

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

Special Publication No. 2010-524802

When remotely operating large machinery such as a crane, the operating feel can be different from operating from inside the cab or when using automatic operation (normal crane operation). For this reason, an operator may feel uncomfortable when operating the crane's remote control device (remote control terminal) in the same way as when operating a normal crane.

The present invention aims to provide a crane remote control system, a remote control terminal, and a crane that are easy to operate remotely.

In order to achieve the above-mentioned object, a representative aspect of the present invention is a remote operation system for a crane, comprising: a swing operation unit that outputs a swing operation signal for the crane; and a swing drive unit that swings the crane based on an output value of the swing operation signal for the crane output from the swing operation unit, wherein the swing operation unit is provided on the crane and includes a first output unit that outputs a first signal that is a swing operation signal for the crane, and a second output unit that is connectable to the crane via a communication line and outputs a second signal that is a swing operation signal for the crane, wherein the swing drive unit swings the crane such that the swing speed of the crane relative to the output value of the first signal changes in accordance with a first characteristic, and swings the crane such that the swing speed of the crane relative to the output value of the second signal changes in accordance with a second characteristic that is different from the first characteristic, and wherein a maximum swing speed of the crane relative to the output value of the second signal is smaller than the maximum swing speed of the crane relative to the output value of the first signal, and the first output unit and the second output unit are not set to the same maximum swing speed .

According to the present invention, it is possible to perform remote crane operation with good operability. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiment.

FIG. 1 is a side view of a crane according to an embodiment of the present invention. FIG. 2 is a perspective view showing the entire operator's cab. FIG. 13 is a diagram showing the left lever (swivel lever). FIG. 4 is a hydraulic circuit diagram for driving a rotation hydraulic motor. FIG. 2 is a diagram showing the external configuration of a remote control terminal. FIG. 2 is a block diagram showing the internal configuration of a remote control terminal; FIG. 4 is a diagram showing the rotation characteristics of a crane. 10 is a flowchart showing a procedure for a control process of a crane rotation operation by a remote control terminal. FIG. 4 is an explanatory diagram of a first-order lag process. FIG. 11 is a hydraulic circuit diagram for driving a hydraulic motor for turning when an electric turning lever is used.

Below, an embodiment of a crane according to the present invention will be described with reference to the drawings.

Figure 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 has a running body 101, a rotating body 103 that is rotatably mounted on the running body via a slewing ring 102, and a boom 104 that is rotatably supported on the rotating body 103. The running body 101 has a track frame 101a and a crawler 101b that is attached to the track frame 101a.

The rotating body 103 is provided with a cab 109, and is equipped with an engine 107 as a prime mover, as well as a hoist drum 105 and a rear winch drum 106 as winch devices. A hoist rope 105a is wound around the hoist drum 105, and the hoist rope 105a is wound or unwound by driving the hoist drum 105, raising or lowering the hook 110. A hoisting rope 106a is wound around the rear winch drum 106, and the hoisting rope 106a is wound or unwound by driving the rear winch drum 106, raising or lowering the boom 104.

The rotating body 103 is driven to rotate by a rotating hydraulic motor 1 (see FIG. 4) via a rotating 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, the rotating body 103 and the running body 101 are structured to be fixed with a swing lock pin 108, which is an example of a fixing means, so that the rotating body 103 does not rotate when assembling the crane 100.

Figure 2 is a perspective view showing the entire cab 109. As shown in Figure 2, the cab 109 is provided with a driver's seat 201 where the operator sits, a right-side group of levers (travel lever, winch operation lever, etc.) 210 that the operator sitting in the driver's seat 201 operates with his right hand, a left-side lever (swing lever) 221 that the operator sitting in the driver's seat 201 operates with his left hand, and a wireless communication antenna 50 for communication. In addition, a display device 231 is provided to the left front of the driver's seat 201, which displays various information such as the operating status of the crane 100 and warnings.

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

The left lever, i.e., the slewing lever 221, is an operating lever for driving the slewing body 103 to rotate by swinging it in the forward and backward directions. As shown in FIG. 3, the slewing lever 221 has a grip 221d that is held by an operator seated in the driver's seat 201. The slewing lever 221 is provided with an accelerator grip 221a and a slewing brake switch 221b.

The accelerator grip 221a is an operating device for increasing or decreasing the rotation speed of the engine 107 by rotating it clockwise or counterclockwise when viewed from above while the operator holds it with his left hand. The accelerator grip 221a is integrated with the turning lever 221, so that the operator can operate the turning lever 221 while operating the accelerator grip 221a with one hand. Note that in this embodiment, in addition to operating the accelerator grip 221a, the rotation speed of the engine 107 can also be increased or decreased by operating the accelerator pedal 261.

The slewing brake switch 221b is a switch for selecting whether or not to apply the slewing brake, which keeps the slewing body 103 from slewing.

As shown in FIG. 2, the driver's cab 109 is provided with a gate lock lever 215. The gate lock lever 215 can be operated in the vertical direction between an unlocked position that blocks the entrance to the driver's cab 109 and a locked position that opens the entrance to the driver's cab 109. When the gate lock lever 215 is in the locked position, it disables all operations of the crane 100. In other words, when the gate lock lever 215 is in the locked position, all operations of the crane 100, such as lifting, traveling, and swinging, are disabled.

Next, the hydraulic drive circuit that drives the rotating body 103 of the crane 100 will be described. Figure 4 is a diagram showing a hydraulic circuit HC1 for driving the rotation hydraulic motor 1. As shown in Figure 4, the hydraulic circuit HC1 is a neutral free rotation hydraulic circuit that connects the rotation hydraulic pump (hereinafter simply referred to as hydraulic pump 8) and the rotation hydraulic motor (hereinafter simply referred to as hydraulic motor 1) with a directional control valve 7.

The hydraulic circuit (slewing drive section) HC1 includes a variable displacement 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 swing brake device 20 that brakes the rotation of the hydraulic motor 1, and a relief valve 9 that determines the maximum pressure of the pressure oil discharged from the hydraulic pump 8. The hydraulic circuit HC1 also includes a directional 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 swing lever device 6, and a relief valve 11 that determines the maximum pressure of the pilot pressure oil discharged from the pilot pump 12.

The swivel lever device 6 includes a swivel lever 221 (see FIG. 4) and pilot valves 6a, 6b connected to the pilot pump 12. The swivel lever device (swivel operation unit/first output unit) 6 is a swivel operation device that performs the swivel operation of the swivel body 103 by generating an operating pilot pressure (swivel operation signal/first signal) by the pilot valves 6a, 6b according to the operation direction and operation amount of the swivel lever 221, and outputting it to the pilot pressure input units 7a, 7b of the directional control valve 7.

The hydraulic motor 1 is connected to pipelines 30a and 30b, which are supplied with pressurized oil discharged from the hydraulic pump 8 via a directional control valve 7. The rotational force of the hydraulic motor 1 is transmitted to the slewing ring 102 (see FIG. 1) via a planetary reduction mechanism (not shown).

The directional control valve 7 is a control valve that has a neutral free position (N) and is inserted in the oil passage between the hydraulic pump 8 and the hydraulic motor 1. The directional control valve 7 has a spool position controlled by the operating pilot pressure (pressure of the pilot pressure oil) generated by the pilot valves 6a and 6b in response to the operation of the turning lever 221 provided in the driver's cab 109.

When the operator operates the rotation lever 221 to the forward rotation side, the operating pilot pressure output from the pilot valve 6a acts on the pilot pressure input section 7a of the directional control valve 7, and the directional control valve 7 switches to the forward rotation position (A). As a result, the pressure oil discharged from the hydraulic pump 8 is supplied to the hydraulic motor 1 via the pipeline 30b, the hydraulic motor 1 rotates forward, and the rotating body 103 rotates in the forward direction (for example, left rotation).

When the operator operates the rotation lever 221 to the reverse side, the operating pilot pressure output from the pilot valve 6b acts on the pilot pressure input section 7b of the directional control valve 7, and the directional control valve 7 switches to the reverse position (B). As a result, the pressure oil discharged from the hydraulic pump 8 is supplied to the hydraulic motor 1 via the pipe 30a, the hydraulic motor 1 rotates in the reverse direction, and the rotating body 103 rotates in the opposite direction (for example, to the right).

When the operator returns the slewing lever 221 from the slewing operation position to the neutral position, the directional control valve 7 switches to the neutral free position (N), and the pipelines 30a and 30b are connected, so that the hydraulic motor 1 can receive an external force and rotate. Therefore, the slewing body 103 is in a free state in which it can rotate by inertia. This state is also called neutral free. When the slewing body 103 is in the neutral free state, the slewing of the slewing body 103 can be stopped by operating the slewing brake device 20 described later and generating a braking force on the slewing body 103. The slewing body 103 can also be stopped by operating the slewing lever 221 in the opposite direction to the slewing direction of the slewing body 103.

The swing brake device 20 is equipped with a hydraulic cylinder (hereinafter referred to as the brake release cylinder 2) having a pad 2p that presses against a swing brake disc (not shown) provided on the output shaft of the hydraulic motor 1, and a swing brake valve 13 that controls the flow of pressurized oil supplied from the pilot pump 12 to the brake release cylinder 2.

The swing brake device 20 is a so-called negative brake, and when the brake release cylinder 2 is connected to the tank, the spring force presses the pad 2p against the swing brake disc (not shown), the swing brake is activated, and a braking force is generated on the swing structure 103. When release pressure is applied to the brake release cylinder 2, the swing brake device 20 is released. When the swing brake device 20 is released, a gap is formed between the swing brake disc (not shown) and the pad 2p, so no braking force is generated on the swing structure 103.

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 pressurized oil from the pilot pump 12 to the brake release cylinder 2 in the release position (C) and prohibits the flow of pressurized oil from the pilot pump 12 to the brake release cylinder 2 in the actuated position (D). When the swing brake valve 13 is switched to the actuated position (D), the brake release cylinder 2 is connected to the tank, and the pressure in the oil chamber of the brake release cylinder 2 becomes the tank pressure.

The hydraulic circuit HC1 is equipped with a gate lock valve 10 provided between the pilot pump 12 and the pilot valves 6a and 6b. The gate lock valve 10 is an electromagnetic switching valve that allows the flow of pressurized oil from the pilot pump 12 to the pilot valves 6a and 6b in the communication position (E) and prohibits the flow of pressurized oil from the pilot pump 12 to the pilot valves 6a and 6b in the cut-off position (F).

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 shutoff position (F), even if the swing brake valve 13 is switched to the release position (C), pressurized oil is not supplied to the brake release cylinder 2, so the swing brake device 20 is in an activated state (i.e., a state in which braking force is generated). In other words, when the gate lock valve 10 is switched to the shutoff position (F), the swing lever 221 cannot be operated. 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).

Furthermore, in this embodiment, the pilot pump 12 and the pilot pressure input section 7a are connected via a branch line 40a, and the branch line 40a is provided with a solenoid valve 41a and a high-pressure selection shuttle valve 42a. Similarly, the pilot pump 12 and the pilot pressure input section 7b are connected via a branch line 40b, and the branch line 40b is provided with a solenoid valve 41b and a high-pressure selection shuttle valve 42b.

Since the solenoid valves 41a and 41b are normally closed (de-energized state), the pilot pressure oil discharged from the pilot pump 12 is not supplied to the pilot pressure input parts 7a and 7b of the directional control valve 7. On the other hand, when the solenoid valves 41a and 41b are energized and 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 parts 7a and 7b of the directional control valve 7.

As described above, the solenoid valves 41a and 41b are normally closed, and therefore the directional control valve 7 is usually switched only by operating the swing lever 221. However, when the solenoid valves 41a and 41b are opened by a command from the remote control terminal 70 (described later), the directional control valve 7 can be switched without operating the swing lever 221. In other words, in this 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 control terminal 70.

As shown in FIG. 4, the crane 100 is also equipped with a controller 3. The controller 3 is configured to include an arithmetic processing device having a CPU, memory devices such as ROM and RAM, 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 is capable of wireless communication with the remote control terminal 70 via a wireless communication antenna 50. Of course, the controller 3 and the remote control terminal 70 may be connected via a wired communication line, and the type of communication line is not particularly limited. For example, when wireless communication is performed, WiFi communication, Bluetooth (registered trademark) communication, or other methods may be used.

The controller 3 is electrically connected to the swing brake valve 13 and the gate lock valve 10. The controller 3 is electrically connected to the swing brake switch 221b provided on the swing lever 221, and switches the swing brake valve 13 to the release position (C) or the operation position (D) based on a signal from the swing brake switch 221b. The controller 3 also switches the gate lock valve 10 to the communication position (E) or the cut-off position (F) based on the operation of the gate lock lever 215 (see FIG. 2) provided in the driver's cab 109.

More specifically, when the slewing brake switch 221b is operated to the off (closed) position, current is supplied from the power supply (not shown) of the controller 3 to the solenoid of the slewing brake valve 13, and the solenoid is excited, switching the slewing brake valve 13 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 supply (not shown) of the controller 3 to the solenoid of the slewing brake valve 13 is cut off, and the solenoid is demagnetized, switching the slewing brake valve 13 to the actuated position (D) by the spring force.

When the gate lock lever 215 is operated to the unlocked 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, switching the gate lock valve 10 to the connected position (E). When the gate lock lever 215 is operated to the locked 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-energized), switching the gate lock valve 10 to the blocked position (F) by the spring force.

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, when the gate lock lever 215 is in the locking position, all operations of the crane 100, such as lifting, traveling, and swinging, are disabled. That is, in this embodiment, when the gate lock valve 10 is switched to the shutoff position (F) by the controller 3, all operations of the crane 100 are stopped.

Next, we will explain the remote control terminal 70 that communicates with the controller 3 to issue commands for remote operation of the crane 100. Figure 5 is an external configuration diagram of the remote control terminal 70, and Figure 6 is an internal configuration diagram (block diagram) of the remote control terminal 70.

As shown in FIG. 5, the remote control terminal (swivel control 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. The remote control terminal 70 includes a processor (not shown) having a CPU, ROM and RAM as storage devices, and other peripheral circuits.

The remote control terminal 70 is formed in a box shape, and on its surface are provided 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 mode setting switch 78 is a slide switch, but the type of switch is not important. Also, dials 75 to 77 are configured to adjust the amount of operation by rotation, but a configuration in which the amount of operation can be adjusted by sliding instead of dials may be used, or switches with other adjustment functions may be used.

The slewing brake switch 71 is used to activate the slewing brake device 20 and has the same function as the slewing brake switch 221b provided on the slewing lever 221.

The power switch 72 is a switch for turning the power of the remote control terminal 70 on and off. 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 blocking position (F).

The engine emergency stop switch 73 is a switch for stopping the engine 107 in the event of an emergency.

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 a speaker provided on the crane 100. The remote control terminal 70 may also be equipped with a speaker.

The turning operation dial 75 is used to turn the rotating body 103; turning it to the left turns left, and turning it to the right turns right. The turning speed of the rotating body 103 changes according to the amount of operation (amount of rotation) of the turning operation dial 75. The change in turning speed follows turning characteristics L2 and L3 (see FIG. 7) described below.

The hydraulic pump flow rate adjustment dial 76 is a dial for adjusting the pump tilt angle (e.g., the tilt angle of the swash plate) of the hydraulic pump 8. The pump tilt angle of the hydraulic pump 8 is changed depending on the amount of operation of the hydraulic pump flow rate adjustment dial 76.

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

The mode setting switch 78 is a switch for setting the rotation mode (rotation characteristics) of the crane 100; sliding it to the left sets the remote normal mode, and sliding it to the right sets the slow speed mode. The remote normal mode and the slow speed mode are modes in which the rotation speed (rate of change) of the rotating body 103 in response to the amount of operation of the rotation operation dial 75 differ from each other (described in detail below).

As shown in FIG. 6, the remote control terminal 70 includes an input unit 81, a processing unit 82, a first-order delay processing unit 86, and an output unit 87.

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

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 the mode is remote normal mode or slow speed mode based on an operation signal from the mode setting switch 78. The current command value table 85 prestores a remote normal mode table 85a corresponding to the remote normal mode and a slow speed mode table 85b corresponding to the slow speed mode.

The remote normal mode table 85a is a table that specifies the current command values of the solenoid valves 41a and 41b in response to the operation amount of the rotation operation dial 75 so that the rotation speed of the crane 100 (rotating body 103) conforms to the rotation characteristic L2 described below.

The slow speed mode table 85b is a table that specifies the current command values for the solenoid valves 41a and 41b in response to the amount of operation of the rotation operation dial 75 so that the rotation speed of the crane 100 conforms to the rotation characteristic L3, which will be described later.

The current command value determination unit 84 determines the current command value to be output to the solenoid valves 41a and 41b by referring to tables 85a and 85b corresponding to the rotation mode determined by the mode determination unit 83.

The first-order lag processing unit 86 applies a first-order lag filter to the current command value signal determined by the current command value determination unit 84, and outputs the first-order lag processed current command value signal 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.

The output unit (second output unit) 87 transmits the current command value signal (swing operation signal/second signal, third signal) that has been subjected to first-order delay processing by the first-order delay 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. The current command value signal corresponding to the remote normal mode corresponds to the "second signal" of the present invention, and the current command value signal corresponding to the slow speed mode corresponds to the "third signal" of the present invention.

The controller 3 receives a current command value signal from the remote control terminal 70, and excites either the solenoid valve 41a or the solenoid valve 41b based on the operation direction of the slewing operation dial 75, and controls the solenoid valves 41a and 41b to a predetermined opening degree according to the current command value. Then, an operation pilot pressure according to the opening degree of the solenoid valves 41a and 41b is input to the pilot pressure input parts 7a and 7b of the directional control valve 7, and the directional control valve 7 switches to the forward rotation position (A) or the reverse rotation position (B). In this way, the rotating body 103 can rotate at a predetermined rotation speed according to the operation of the slewing operation dial 75.

Next, the rotation characteristics of the crane 100 according to the rotation mode will be described. Figure 7 is a diagram showing the rotation characteristics of the crane 100. In Figure 7, the horizontal axis is the operation amount of the rotation operation dial 75 or the rotation lever 221, and the vertical axis is the operation pilot pressure input to the pilot pressure input parts 7a and 7b of the directional control valve 7. In the figure, the right side of the center of the horizontal axis shows the rotation characteristics when the crane 100 is rotating to the right, and the left side shows the rotation characteristics when the crane 100 is rotating to the left. Since the rotation characteristics are the same for left and right rotation, the following explanation will explain the rotation characteristics when rotating to the right, and will omit the explanation of the rotation characteristics when rotating to the left.

In addition, since the operating pilot pressure and the rotation speed of the crane 100 (rotating body 103) are correlated, the relationship of the operating pilot pressure to the operation amount of the rotation operation dial 75 is equal to the relationship of the rotation speed to the operation amount of the rotation operation dial 75. Therefore, the operating pilot pressure on the vertical axis is synonymous with the rotation speed of the crane 100. In other words, it can also be said that Figure 7 shows the relationship of the rotation speed of the crane 100 to the operation amount of the rotation operation dial 75 or the rotation lever 221.

Figure 7 shows three rotation characteristics L1, L2, and L3. In Figure 7, the solid line shows rotation characteristic L1 (first characteristic) during normal operation of the crane 100 (operation by operating the rotation lever 221), the dashed line shows rotation characteristic L2 (second characteristic) when the rotation mode is set to the remote normal mode, and the dashed double-dashed line shows rotation characteristic L3 (third characteristic) when the rotation mode is set to the slow speed mode.

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

The turning characteristic L2 has a characteristic that the rate of change of the turning speed of the rotating body 103 changes in two stages with respect to the amount of operation of the turning operation dial 75. The range of the turning operation dial 75 from zero (neutral position) to S11 is a play portion, so the turning body 103 does not turn even if the turning operation dial 75 is operated. When the amount of operation of the turning operation dial 75 becomes S11, the operating pilot pressure becomes P5 and the turning speed becomes V5. In other words, when the operator operates the turning operation dial 75 from the neutral position to S11, the turning body 103 starts turning at a speed V5. Then, in the range of the amount of operation of the turning operation dial 75 from S11 to S12 (predetermined value), as the amount of operation increases, the operating pilot pressure (turning speed) increases at a first slope, and when the amount of operation becomes S12, the operating pilot pressure becomes P3 (the turning speed is V3). In addition, when the amount of operation of the turning operation dial 75 is in the range from S12 to S13, the operating pilot pressure (turning speed) increases at a second gradient as the amount of operation increases. Then, when the amount of operation of the turning operation dial 75 becomes S13 (maximum), the operating pilot pressure becomes P2 (turning speed is V2).

Here, the first tilt is gentler than the second tilt. In other words, the rate of change of the rotation speed of the rotating body 103 in the range from S11 to S12 (first half of the operation) is smaller than the rate of change of the rotation speed of the rotating body 103 in the range from S12 to S13 (second half of the operation). Therefore, when the rotating body 103 rotates according to the rotation characteristic L2, when the operation amount of the rotation operation dial 75 is in the range from S11 to S12, the rotating body 103 rotates slowly at a rotation speed corresponding to the first tilt, and when the operation amount of the rotation operation dial 75 is in the range from S12 to S13, the rotating body 103 rotates slightly faster at a rotation speed corresponding to the second tilt.

The rotation characteristic L3 has a characteristic in which the rate of change of the rotation speed of the rotating body 103 is constant with respect to the amount of operation of the rotation operation dial 75. The range of the rotation operation dial 75 from zero (neutral position) to S11 is a play portion, so the rotating body 103 does not rotate even if the rotation operation dial 75 is operated. When the amount of operation of the rotation operation dial 75 becomes S11, the operating pilot pressure becomes P5 and the rotation speed becomes V5. Then, in the range of the amount of operation of the rotation operation dial 75 from S11 to S13 (maximum), as the amount of operation increases, the operating pilot pressure (rotation speed) increases linearly with a third slope. When the amount of operation becomes S13 (maximum), the operating pilot pressure becomes P4 (rotation speed is V4).

Here, the difference between the rotation characteristics L1, L2, and L3 will be explained. The maximum rotation speed of the rotating body 103 in the rotation characteristic L1 is the greatest among the three rotation characteristics L1, L2, and L3, followed by the maximum rotation speed of the rotation characteristic L2, and the maximum rotation speed of the rotation characteristic L3 is the smallest. In other words, the rotation speeds are V1>V2>V4. Therefore, the rotating body 103 cannot be rotated at a rotation speed greater than the rotation speed V2 using the remote control terminal 70.

The rotation characteristics L2 and L3 are characteristics that are applied when rotating the rotating body 103 using the remote control terminal 70, and the maximum rotation speed of the rotating body 103 is greater for the rotation characteristic L2 than for the rotation characteristic L3 (rotation speed V2>V3). Moreover, over the entire range of the operation amount of the rotation operation dial 75, the rotation speed of the rotation characteristic L2 is greater than that of the rotation characteristic L3. Therefore, when operating the rotating body 103 using the remote control terminal 70, the rotation characteristic L2 (remote normal mode) allows the rotating body 103 to rotate faster than the rotation characteristic L3 (slow speed mode).

In addition, the rate of change (slope) of the rotation speed of the rotation characteristic L2 is greater than the rate of change of the rotation speed of the rotation characteristic L3. Therefore, when the operator rotates the rotation operation dial 75 to a specified position, the rotating body 103 rotates more slowly in the slow speed mode than in the remote normal mode.

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

As shown in FIG. 8, the input unit 81 acquires the amount of operation 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 slow speed mode or not (S2). If the mode determination unit 83 determines that it is the slow speed mode (S2/Yes), the current command value determination unit 84 determines the current command value of the solenoid valves 41a, 41b by referring to the slow speed mode table 85b (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 first-order delay processing unit 86 does not perform processing.

The controller 3 receives a current command value signal 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 crane 100 is rotated based on the amount and direction of operation of the rotation operation dial 75 of the remote control terminal 70. At this time, the rotating body 103 rotates at a rotation speed according to the rotation characteristic L3 corresponding to the slow speed mode.

On the other hand, if the mode determination unit 83 determines in S2 that the slow speed mode is not selected (S2/No), the current command value determination unit 84 determines the current command value of the solenoid valves 41a and 41b by referring to the remote normal mode table 85a (S5), and outputs a signal of the current command value to the first-order delay processing unit 86. Then, the first-order delay processing unit 86 determines whether the rate of change of the operation amount of the turning operation dial 75 is equal to or greater than the allowable value (S6). If the rate of change of the operation amount of the turning operation dial 75 is equal to or greater than the allowable value (S6/Yes), that is, if the operator has suddenly operated the turning operation dial 75, the first-order delay processing unit 86 performs first-order delay processing on the signal of the current command value output from the current command value determination unit 84 (S7). After that, the output unit 87 transmits the signal of the current command value subjected to first-order delay processing to the controller 3 via the wireless communication antenna 51 (S8).

On the other hand, if the rate of change in the amount of operation 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, no processing is performed by the first-order delay processing unit 86.

The controller 3 receives a current command value signal 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 rotating body 103 rotates at a rotation speed according to the rotation characteristic L2 corresponding to the remote normal mode.

Now, the first-order delay processing of S7 will be described in detail with reference to FIG. 9. FIG. 9 is an explanatory diagram of the first-order delay processing, 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 abruptly operates the turning operation dial 75 at time t1, the output signal of the current command value rises abruptly at the timing of time t1. Then, when the operator abruptly returns the turning operation dial 75 to its original position at time t3, the output signal of the current command value falls abruptly at the timing of time t3 (output). On the other hand, when the first-order delay control is applied to the output signal, the output signal rises gradually from time t1 to time t2, and falls gradually from time t3 to time t4 (first-order delay control).

In this way, the primary delay processing unit 86 performs primary delay processing (filter processing) on the output signal, so that even if the rotation operation dial 75 is operated suddenly, the rotating body 103 operates with a predetermined delay, preventing a sudden change (acceleration/deceleration) in the rotation speed of the rotating body 103.

As described above, this embodiment provides the following advantages:

When the crane 100 is operated to rotate using the remote control terminal 70, the rotation speed follows the rotation characteristics L2 and L3, so the remote operation of the crane can be performed with a feeling similar to that of a normal crane operation. To explain in more detail, the rate of change of the rotation speed in the rotation characteristics L2 and L3 is smaller than the rate of change of the rotation speed in the rotation characteristic L1. Therefore, even if the rotation operation dial 75 and the rotation lever 221 are operated by the same amount of operation, the rotation speed of the rotation operation dial 75 increases more slowly. Since the rotation operation dial 75 is small, if the rotation speed increases suddenly with just a small operation, the feeling is different from that of normal crane operation, and the operator feels uncomfortable with the operability. This feeling is particularly noticeable in the rotation operation of a crane. However, by controlling the rotation speed according to the rotation characteristics L2 and L3 as in this embodiment, the remote operation of the crane 100 can be performed with a feeling similar to that of a normal crane operation.

In other words, when a crane is operated remotely, the operator cannot feel the crane's rotation behavior. Therefore, if the rotation characteristics during remote operation were the same as those when operating from inside the cab 109, the operator would feel uncomfortable operating the crane. In this regard, in this embodiment, when operating remotely, the crane can be rotated according to rotation characteristics L2, L3 that are different from the rotation characteristic L1 during normal operation, improving operability when operating the crane remotely.

In addition, since the rotation speed of the rotating body 103 is slow in the initial stage of rotation when remotely operated, the operator can easily visually understand that the crane 100 is rotating, even if he or she does not intuitively feel the behavior of the crane 100 in the initial stage of rotation.

In addition, the rotation characteristic L2 allows the rate of change of the rotation speed to change in two stages depending on the range of the amount of operation of the rotation operation dial 75, making it easy for the operator to use remote control. Moreover, the work efficiency of remote control is also good. And when it is desired to move the rotating body 103 quickly mid-rotation, the rotation speed can be quickly increased by increasing the amount of operation of the rotation operation dial 75. This improves work efficiency.

In addition, the rotation characteristic L3 rotates the rotating body 103 at a slower speed than the rotation characteristic L2, and is therefore suitable when it is desired to rotate the rotating body 103 slowly. For example, as described below, when assembling the crane 100 on-site, there is a process of fixing the rotating body 103 to the running body 101 with the rotation lock pin 108 (see FIG. 1). In this process, if the rotating body 103 is rotated with the rotation characteristic L3 (slow speed mode), it becomes easier to align the position for inserting the rotation lock pin 108, improving workability.

In addition, even if the rotation operation dial 75 is operated suddenly, the output signal is delayed by the first-order delay processing unit 86, so the rotating body 103 does not rotate suddenly in response to the operation of the rotation operation dial 75. This improves operability and safety.

In addition, since the maximum rotation speed of the rotation characteristics L2 and L3 is smaller than the maximum rotation speed of the rotation characteristic L1, the crane 100 can be rotated slowly when operated by the remote control terminal 70. This allows safer work to be performed in the process of assembling the crane 100 on-site. Furthermore, in assembly operations that require remote operation, there is no need to increase the speed compared to normal crane operation. Therefore, operating the crane 103 using the remote control terminal 70 with the rotation characteristics L2 and L3 set as in this embodiment also has the effect of preventing the rotating body 103 from rotating excessively quickly.

Here, we will explain in detail the assembly process of the crane 100 (mainly the process of attaching the crawler 101b to the track frame 101a of the running body 101).

(Step 1) The rotating body 103 of the crane 100 and the track frame 101a of the running body 101 (hereafter referred to as the main body) are transported to a designated location by trailer.

(Step 2) The operator gets into the cab 109 and starts the engine 107. If the remote control terminal 70 is provided with a start switch for the engine 107, the engine 107 may be started by the remote control terminal 70.

(Step 3) The operator jacks up the main body, lifts it off the trailer stand, and moves the trailer.

(Step 4) In order to attach the crawler 101b to the track frame 101a of the running body 101, the operator operates the rotation operation dial 75 of the remote control terminal 70 to slowly rotate the rotating body 103 to a predetermined angle (e.g., 90 degrees) relative to the running body 101. At this time, it is recommended to set the remote normal mode (rotation characteristic L2). Depending on the model, in this step, the crawler 101b is suspended and rotated by an auxiliary lifting device or the like attached to the bottom of the boom 104 of the crane 100, and then it is slowly moved close to the track frame 101a before proceeding to step 6.

(Step 5) To insert the swing lock pin 108, the operator slowly swings the swing unit 103 until it is in the specified position. At this time, it is recommended to set the slow speed mode (swing characteristic L3). Then, once the swing unit 103 and the running unit 101 are aligned, the swing lock pin 108 is inserted to fix the swing unit 103 and the running unit 101 in place. Then, the engine 107 is stopped. The engine 107 may be stopped in the cab 109 or by using the emergency engine stop switch 73 on the remote control terminal 70.

(Step 6) Once the swivel lock pin 108 is attached, the operator attaches the crawler 101b to the track frame 101a. This completes the assembly work of attaching the crawler 101b to the track frame 101a.

In this assembly process, the crane 100 can be rotated by operating the remote control terminal 70, allowing assembly to be performed with good workability. When rotating the rotating body 103 to a specified angle, the remote normal mode can be set, allowing the rotating body 103 to be rotated quickly, improving workability. In addition, when inserting the rotation lock pin 108, the rotating body 103 can be rotated at a slow speed in the slow speed mode, making it easy to insert the rotation lock pin 108. In this way, by appropriately setting the mode setting switch 78 and performing the assembly work, work efficiency can be improved.

Reference to other embodiments
The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention, and all technical matters included in the technical ideas described in the claims are the subject of the present invention. The above-described embodiment shows a preferred example, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the attached claims.

For example, in the above embodiment, a configuration was exemplified in which two turning modes (turning characteristics), a remote normal mode and a slow speed mode, were set on the remote control terminal 70, but the number of turning modes that can be set is not limited to two. The number of turning modes that can be set may be one, or three or more. When there is one turning mode, the mode setting switch 78 is not required, and only one current command value table is required.

In addition, in the turning characteristic L2, a configuration in which the rate of change of the turning speed changes in two stages has been exemplified, but a configuration in which the rate of change does not change, or a configuration in which it changes in three or more stages, is also acceptable. In addition, the rate of change of the turning speed in turning characteristic L3 may also change in multiple stages.

In the above embodiment, the remote control terminal 70 transmits a current command value corresponding to the rotation mode to the controller 3, and the controller 3 controls the solenoid valves 41 and 41b according to the received current command value. However, instead of this configuration, the controller 3 may determine a current command value for the solenoid valves 41a and 41b and control the solenoid valves 41a and 41b. Specifically, the remote control terminal 70 is configured to have only the functions of the input unit 81 and the output unit 87, and the controller 3 is configured to have a processing unit 82 and a first-order delay processing unit 86. The controller 3 then determines a current command value by referring to the current command value table 85 based on the rotation mode information transmitted from the remote control terminal 70 and the information on the operation amount of the rotation operation dial 75, and controls the solenoid valves 41a and 41b based on the determination.

In addition, when there is only one rotation mode, the controller 3 may set a flag based on an input signal from the remote control terminal 70, and when the flag is set, the rotating body 103 may be rotated with rotation characteristics different from those of the normal rotation operation of the crane 100.

The swivel lever device 6 may also be configured with an electric swivel lever, which generates and outputs an electric signal (first signal) according to the direction and amount of operation of the electric swivel lever. For example, FIG. 10 is a hydraulic circuit diagram for driving a hydraulic motor for swivel when an electric swivel lever is used. As shown in FIG. 10, if the electric swivel lever 206 and the controller 3 are electrically connected and the controller 3 is configured to output an excitation signal to the input parts 207a and 207b of the electromagnetic directional control valve 207 in response to the operation of the swivel lever 206, the same effect as in the above embodiment can be achieved. In addition, in the case of automatic operation in which the controller 3 automatically generates and outputs an electric signal to perform the swivel operation, the controller 3 functions as a swivel lever device (swivel operation part) and swivels according to the first characteristic.

The first-order delay processing unit 86 may be provided as necessary. If the first-order delay processing unit 86 is not provided, the output unit 87 may simply output the current command value signal (second signal, third signal) determined by the current command value determination unit 84 to the controller 3 as is.

Although a crawler crane has been given as an example of a crane, the present invention is not limited to this and can be applied to any type of cranes, including other mobile cranes such as wheel cranes, truck cranes, rough terrain cranes, and all-terrain cranes, as well as tower cranes, overhead cranes, jib cranes, retractable cranes, stacker cranes, gantry cranes, unloaders, and foundation machines such as earth drills.

1 Swing hydraulic motor 3 Controller 6 Swing lever device (swing operation unit/first output unit)
6a, 6b Pilot valve (first output part)
7 Directional 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 control terminal (swing operation unit/second output unit)
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 determination section 84 Current command value determination section 85 Current command value table 85a Remote normal mode table 85b Slow speed mode table 86 First order lag processing section 87 Output section (second output section)
100 Crane 101 Traveling body 102 Swivel ring 103 Swivel 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 Swing brake switch 221c Touch sensor 221d Grip 231 Display device 251 Hoist drum brake pedal 252 Rear drum brake pedal 261 Accelerator pedal 262 Swing brake pedal HC1 Hydraulic circuit (swing drive unit)
L1 First characteristic L2 Second characteristic L3 Third characteristic

Claims (9)

A crane remote control system, comprising:
A rotation operation unit that outputs a rotation operation signal for the crane;
a rotation drive unit that rotates the crane based on an output value of the rotation operation signal of the crane output from the rotation operation unit,
The turning operation unit is
A first output unit provided in the crane and configured to output a first signal which is a rotation 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 that is a rotation operation signal for the crane,
The turning drive unit is
Rotating the crane so that a rotation speed of the crane relative to an output value of the first signal varies in accordance with a first characteristic;
Rotating the crane so that a rotation speed of the crane relative to an output value of the second signal changes according to a second characteristic different from the first characteristic ;
A crane remote control system characterized in that a maximum rotation speed of the crane for an output value of the second signal is smaller than a maximum rotation speed of the crane for an output value of the first signal, and the first output unit and the second output unit are not set to the same maximum rotation speed . The crane remote control system according to claim 1,
a crane remote control system, characterized in that the magnitude relationship of the rotation speed of the crane is reversed between the second characteristic and the first characteristic at a predetermined value in the range of the output value of the first signal or the second signal . The crane remote control system according to claim 2,
a rate of change of the rotation speed of the crane in the second characteristic includes a portion which is larger when the range of the output value of the second signal exceeds a predetermined value than when the range of the output value is equal to or smaller than the predetermined value. The crane remote control system according to any one of claims 1 to 3 ,
The second output unit outputs a third signal which is a rotation operation signal for the crane,
A crane remote control system characterized in that the rotation drive unit rotates the crane so that a rotation speed of the crane relative to an output value of the third signal changes according to a third characteristic different from the second characteristic. The crane remote control system according to claim 4 ,
A crane remote control system, wherein the third characteristic has a smaller rate of change in the rotation speed of the crane than the second characteristic. The crane remote control system according to claim 4 or 5 ,
A crane remote control system, characterized in that the third characteristic is a smaller rotation speed of the crane relative to an output value of a rotation operation signal of the crane than the second characteristic. The crane remote control system according to any one of claims 1 to 6 ,
A remote control system for a crane, characterized in that the rotation speed of the crane is controlled with a predetermined delay in response to the output of a rotation operation signal for the crane from the second output section. A remote control terminal used in the crane remote control system according to any one of claims 1 to 7 , comprising the second output section. A crane,
a rotation drive unit that rotates the crane so that a rotation speed changes according to a first characteristic based on an operation of an operator on board the crane or an instruction of a controller mounted on the crane,
The slewing drive unit rotates the crane so that a slewing speed changes according to a second characteristic different from the first characteristic based on an instruction from a remote control terminal that can be connected from outside the crane via a communication line ,
A crane characterized in that a maximum rotation speed of the crane in the second characteristic is smaller than a maximum rotation speed of the crane in the first characteristic, and the same maximum rotation speed is not set for the first characteristic and the second characteristic .

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