JP2024104769A - Cable crane, transportation method and construction method - Google Patents

Abstract

To enable a hoisting device such as a bucket to be stopped when a traverse trolley stops, even if the distance from the traverse trolley to the hoisting device changes while the traverse trolley is decelerating.
[Solution] A cable crane 20 includes a traverse trolley 22 installed on the main ropes 21 so as to move along the main ropes 21, a winch 23 for driving the traverse trolley 22, a hoisting device 29 suspended from the traverse trolley 22, a first position measuring device 31 for measuring the position of the traverse trolley 22, a second position measuring device 32 for measuring the position of the hoisting device 29, and a control device 40. If the sway angle of the hoisting device 29 is equal to a target value, the control device 40 maintains the deceleration of the traverse trolley 22, if the sway angle of the hoisting device 29 is greater than the target value, the control device 40 reduces the deceleration of the traverse trolley 22, and if the sway angle of the hoisting device 29 is smaller than the target value, the control device 40 increases the deceleration of the traverse trolley 22.
[Selected Figure] Figure 1

Description

The present invention relates to a cable crane, a transportation method, and a construction method.

Cable cranes that are erected between mountains are used to construct concrete structures such as dam embankments in valleys. A cable crane is equipped with a main rope, a traverse trolley, and a bucket. The main rope is stretched across the mountains, the traverse trolley runs along the main rope, and the bucket is suspended from the traverse trolley, into which concrete is loaded.

When a cable crane is used to transport concrete from a mountain to a valley, the traveling trolley slows down and stops above the valley, causing the bucket to swing. After the bucket swing stops, the bucket is lowered from the traveling trolley. The concrete is then dropped from the bucket. Because of this procedure, the bucket swing causes the concrete pouring cycle to become longer, which ultimately causes the construction period of concrete structures to be longer.

To solve these problems, the technology described in Patent Document 1 has been proposed. Patent Document 1 discloses a technology in which the bucket sway angle and its angular velocity are measured by a measuring device, and the deceleration of the traverse trolley is controlled by a control device based on the sway angle and angular velocity, taking into account the braking distance of the traverse trolley, so that the bucket sway is offset. With the technology in Patent Document 1, the bucket sway stops when the traverse trolley stops.

JP 2022-154200 A

The technology of Patent Document 1 is effective under the condition that the distance from the traverse trolley to the center of gravity of the bucket is constant during deceleration of the traverse trolley. However, if the distance from the traverse trolley to the center of gravity of the bucket changes during deceleration of the traverse trolley, the technology of Patent Document 1 does not necessarily stop the bucket from swinging when the traverse trolley stops.
Therefore, an object of the present invention is to enable the hoisting device, such as a bucket, to be stopped when the traverse trolley stops, even if the distance from the traverse trolley to the hoisting device changes while the traverse trolley is decelerating.

According to a first aspect of the present invention for solving the above problems, a cable crane comprises a main rope stretched between the peaks above a valley between the peaks, a traverse trolley installed on the main rope so as to move along the main rope, a drive unit for driving the traverse trolley, a sling suspended from the traverse trolley, a first position measuring device for measuring the position of the traverse trolley, a second position measuring device for measuring the position of the sling, and a control device for controlling the drive unit to control the speed of the traverse trolley, and when the control device decelerates the traverse trolley, the control device controls the speed of the traverse trolley measured by the first position measuring device. The control device calculates the swing angle of the hoisting device based on the position measured by the second position measuring device, and the control device compares the calculated swing angle of the hoisting device with a target value. If the swing angle of the hoisting device is equal to the target value, the control device decelerates the traverse trolley to maintain the deceleration of the traverse trolley. If the swing angle of the hoisting device is greater than the target value, the control device decelerates the traverse trolley to reduce the deceleration of the traverse trolley. If the swing angle of the hoisting device is smaller than the target value, the control device decelerates the traverse trolley to increase the deceleration of the traverse trolley.

According to a second aspect of the present invention, the control device calculates the target value based on the distance from the position measured by the first position measuring device to the destination.

According to a third aspect of the present invention, the control device calculates the target value to be smaller as the distance from the position measured by the first position measuring device to the destination becomes smaller.

According to a fourth aspect of the present invention, the cable crane further includes a lifting winch that raises and lowers the hoisting device, and when the control device decelerates the traverse trolley, the control device operates the lifting winch to lower the hoisting device.

According to a fifth aspect of the present invention, there is provided a method of transporting a load held by a hoist using a cable crane equipped with a main rope stretched between mountains above a valley between the mountains, a traverse trolley installed on the main rope so as to move along the main rope, and a hoist suspended from the traverse trolley, the method comprising: measuring the positions of the traverse trolley and the hoist; and adjusting the speed of the hoist based on the measured positions of the traverse trolley and the hoist; The swing angle of the sling is calculated, and the calculated swing angle of the sling is compared with a target value. If the swing angle of the sling is equal to the target value, the traverse trolley is decelerated to maintain the deceleration of the traverse trolley. If the swing angle of the sling is greater than the target value, the traverse trolley is decelerated to reduce the deceleration of the traverse trolley. If the swing angle of the sling is smaller than the target value, the traverse trolley is decelerated to increase the deceleration of the traverse trolley.

According to a sixth aspect of the present invention, a construction method is provided for constructing a structure in the valley by using the transportation method to transport ready mixed concrete as the suspended load to the valley.

According to the present invention, even if the distance from the traverse trolley to the hoisting device changes while the traverse trolley is decelerating, the hoisting device stops when the traverse trolley stops.

FIG. 1 is a perspective view of a cable crane at a construction site. FIG. 2 is a block diagram of a cable crane. FIG. 3 is a side view of the traverse trolley and hoisting gear of the cable crane. FIG. 4 is a diagram showing the trajectory of the sling. FIG. 5 is a graph showing the change in speed of the traverse trolley. FIG. 6 is a graph showing the relationship between the distance from the traverse trolley to the destination and the target value, and the relationship between that distance and the swing angle. FIG. 7 is a graph showing the relationship between the distance from the traverse trolley to the destination and the target value.

The following describes embodiments with reference to the drawings. The features and technical effects of the embodiments can be understood from the following detailed description and drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. The drawings are provided for illustrative purposes only, and therefore the scope of the present invention is not limited to the illustrations in the drawings.

[1. Overview of the construction system]
FIG. 1 is a perspective view of a construction system 1.
The construction system 1 constructs a structure 99, such as a dam embankment, in a valley 93 between mountains 91 and 92. The construction system 1 transports materials, such as ready mixed concrete, from the mountain 91 or mountain 92 to the valley 93 for the construction of the structure 99. The construction system 1 may transport materials that are no longer needed in the valley 93 from the valley 93 to the mountain 91 or mountain 92.

The construction system 1 includes a concrete supply facility 10 and a cable crane 20.

The concrete supply equipment 10 is constructed on the side of the mountain 92. The concrete supply equipment 10 produces ready-mix concrete and supplies the produced ready-mix concrete to the cable crane 20. Note that another concrete supply equipment may be constructed on the side of the mountain 92 together with the concrete supply equipment 10 or instead of the concrete supply equipment 10.

Cable crane 20 is installed between peaks 91 and 92. Cable crane 20 receives ready-mixed concrete from concrete supply equipment 10 and transports the ready-mixed concrete to valley 93. Cable crane 20 may transport materials other than ready-mixed concrete to valley 93. Cable crane 20 may transport materials from peak 92 to valley 93. Cable crane 20 may transport materials that are no longer needed in valley 93 from valley 93 to peak 91 or peak 92. Hereinafter, objects such as ready-mixed concrete and materials transported by cable crane 20 are referred to as suspended loads.

[2. Concrete supply equipment]
The concrete supply facility 10 comprises a batcher plant 11, a bunker track 12 and a transport vehicle 13.

The batcher plant 11 is constructed on the side of a mountain 92. The batcher plant 11 mixes cement, water, and aggregate to produce ready-mix concrete.

The bunker track 12 is laid along the valley 93 from the batcher plant 11 on the side of the mountain 92.

.
The transport vehicle 13 is configured by, for example, a transfer car or a bucket cart. The transport vehicle 13 is capable of traveling on the bunker track 12 along the bunker track 12. The transport vehicle 13 repeatedly performs the following operations.
First, the transport vehicle 13 receives a supply of ready-mixed concrete at the batcher plant 11 and loads the ready-mixed concrete. The transport vehicle 13 transports the ready-mixed concrete from the batcher plant 11 to the transfer location P1 along the bunker track 12. Next, the transport vehicle 13 transfers the ready-mixed concrete to a hoisting tool 29 described below at the transfer location P1. Next, the transport vehicle 13 returns to the batcher plant 11 to receive the ready-mixed concrete.
The transfer location P1 is located along the bunker track 12 and below the main ropes 21 described below. In other words, when looking at the bunker track 12 and the main ropes 21 from above, the point where the bunker track 12 and the main ropes 21 intersect is the transfer location P1.

[3. Cable Crane]
The cable crane 20 will be described in detail with reference to Figures 1 to 3. Figure 2 is a block diagram of the control configuration of the cable crane 20. Figure 3 is a side view of the traverse trolley 22 and the hoisting device 29 of the cable crane 20.

The cable crane 20 is a one-sided mobile cable crane among the rail-type. A rail-type cable crane is one in which one or both ends of the main ropes 21, which are erected between peaks 91 and 92, move along valleys 93. A one-sided mobile cable crane is one in which one or both ends of the main ropes 21 move along valleys 93. The cable crane 20 may be a two-sided mobile cable crane among the rail-type, or may be a fixed cable crane rather than a rail-type. A two-sided mobile cable crane is one in which both ends of the main ropes 21 move along valleys 93. A fixed cable crane is one in which both ends of the main ropes 21 are fixed and do not move.

The cable crane 20 includes a main rope 21, a traverse trolley 22, a first winch 23, a first tower 24, a pair of second towers 25, a track 26, a traveling trolley 27, a second winch 28, a hoisting device 29, a lifting winch 30, a first position measuring device 31, a second position measuring device 32, a control device 40, and a maneuvering device 41.

The first tower 24 is also called the main tower. The first tower 24 is constructed standing on the middle or top of the mountain 91.

The second tower 25 is also called a cable tower. The second tower 25 is constructed standing on the top or middle of the mountain 92. The installation location of the second tower 25 is higher than the installation locations of the batcher plant 11 and the bunker track 12, and the second tower 25 is installed closer to the top of the mountain 92 than the batcher plant 11 and the bunker track 12. The two second towers 25 are lined up along the valley 93 with a gap between them.

The rail 26 is installed on the peak 92 along the valley 93. More specifically, one end of the rail 26 is connected to one of the second towers 25, particularly to the top thereof, and the other end of the rail 26 is connected to the other second tower 25, particularly to the top thereof, and the rail 26 is suspended between these second towers 25.

The traveling trolley 27 is supported by the track 26 and is arranged so as to be able to travel on and along the track 26. The traveling trolley 27 is connected to a traveling towing cable, which is wound around the second winch 28.

The second winch 28 is installed on the mountain 92. More specifically, the second winch 28 is installed in the machine room 82 on the mountain 92. The second winch 28 pulls the traveling trolley 27 so that the traveling trolley 27 travels along the track 26 by applying tension to the traveling traction cable by winding and unwinding the traveling traction cable. The second winch 28 has a drum around which the traveling traction cable is wound, and a motor that drives the drum. Note that the traveling trolley 27 may be self-propelled instead of being a towed type. Self-propelled means that a motor is provided on the traveling trolley 27 and the traveling trolley 27 travels by the power of the motor.

The main rope 21 is suspended between the peaks 91 and 92 above the valley 93. More specifically, one end of the main rope 21 is connected to the first tower 24, particularly to its top, at the peak 91, and the other end of the main rope 21 is connected to the traveling trolley 27 at the peak 92, so that the main rope 21 is suspended between the first tower 24 and the traveling trolley 27.

When the cable crane 20 is fixed, one second tower 25 is constructed standing on the top or middle of the mountain 92, and the main rope 21 is stretched between the first tower 24 and the second tower 25. When the cable crane 20 is movable on both sides, two first towers 24 are constructed standing on the top or middle of the mountain 91, a rail is stretched between the two first towers 24, the second running trolley runs along the rail, and the main rope 21 is stretched between the second running trolley and the running trolley 27.

The traverse trolley 22 is supported by the main ropes 21 and is arranged so as to be able to run on and along the main ropes 21. The traverse trolley 22 is connected to a traverse traction cable, which is wound around the first winch 23.

The first winch 23 is a drive device installed on the mountain 91. More specifically, the first winch 23 is installed in a machine room 81 on the mountain 91. The first winch 23 pulls the traverse trolley 22 so that the traverse traction cable runs along the main ropes 21 by applying tension to the traverse traction cable by winding and unwinding the traverse traction cable. The first winch 23 has a drum around which the traverse traction cable is wound, and a motor that drives the drum. Note that the traverse trolley 22 may be self-propelled rather than being a towed type. Self-propelled means that a motor is provided as a drive device on the traverse trolley 22, and the traverse trolley 22 runs by the power of the motor.

The hoisting device 29 is suspended from the traverse trolley 22 by a hoisting cable 30a and holds a suspended load. The hoisting device 29 is connected to the lifting winch 30 via the hoisting cable 30a. The hoisting device 29 is raised and lowered by winding and unwinding the hoisting cable 30a by the lifting winch 30.

The lifting device 29 has a block 29a and a bucket 29b. The block 29a has a movable pulley around which the hoisting cable 30a is wound. When the lifting winch 30 pays out the hoisting cable 30a, the block 29a rises, and when the lifting winch 30 winds up the hoisting cable 30a, the block 29a descends. The bucket 29b is suspended from the block 29a. The bucket 29b contains and holds a load, particularly concrete. The bucket 29b has a switch 29c at its bottom that is opened and closed by remote control. When the switch 29c is closed, the load is held in the bucket 29b, and when the switch 29c is opened, the load is dropped from the bucket 29b.

The lifting winch 30 is installed on the mountain 91, more specifically, in the machine room 81. The lifting winch 30 raises and lowers the hoisting device 29 by applying tension to the hoisting cable 30a by winding and unwinding the hoisting cable 30a. The lifting winch 30 has a drum around which the hoisting cable 30a is wound, and a motor that drives the drum.

The first position measuring device 31 is attached to the traversing trolley 22. The first position measuring device 31 receives satellite waves from multiple satellites and measures the three-dimensional position of the traversing trolley 22 according to the positioning method of the Global Navigation Satellite System (GNSS). The position measured by the first position measuring device 31 is expressed in a three-dimensional Cartesian coordinate system. For example, the X coordinate in the Cartesian coordinate system is either latitude or longitude converted into distance, the Y coordinate is the other converted into distance, and the Z coordinate is altitude (elevation). The first position measuring device 31 periodically measures the position of the traversing trolley 22 at short intervals and transfers the measured position to the control device 40 wirelessly or via wire each time it measures.

The second position measuring device 32 is attached to the sling 29, specifically to the block 29a. Like the first position measuring device 31, the second position measuring device 32 measures the position of the sling 29 periodically at short intervals according to the GNSS positioning method, and transfers the measured position to the control device 40 wirelessly or via cable each time a measurement is made. The coordinate system of the position measured by the second position measuring device 32 is the same as the coordinate system of the position measured by the first position measuring device 31.

Note that the position measuring instruments 31 and 32 are not limited to measuring instruments using the GNSS positioning method. For example, the position measuring instruments 31 and 32 may be tracking optical surveying instruments installed on mountain 91, mountain 92, or valley 93. In this case, the first position measuring instrument 31 measures the three-dimensional position of the traverse trolley 22 by optically aiming at the traverse trolley 22 so as to track it, and the second position measuring instrument 32, like the first position measuring instrument 31, also measures the three-dimensional position of the sling 29 by optical aiming.

The control device 40 and the maneuvering device 41 are installed in a location that overlooks the entire construction site, i.e., the entire valley 93, such as a control room on the middle or top of the mountains 91, 92. The control device 40 has a computer and various electric circuits. The control device 40 communicates with the position measuring devices 31, 32 by wire or wirelessly, and obtains the positions of the traverse trolley 22 and the hoisting device 29 measured by the position measuring devices 31, 32.

The control device 40 is connected by wire or wirelessly to the drive circuits of the winches 23, 28, 30 and the switch 29c, and controls the winches 23, 28, 30 and the switch 29c through the drive circuits. The control device 40 controls the first winch 23, which causes the traverse trolley 22 to move along the main rope 21 and also controls the speed and acceleration of the traverse trolley 22. The control device 40 controls the second winch 28, which causes the end of the main rope 21 and the running trolley 27 to move along the rail 26. The control device 40 controls the lifting winch 30, which causes the hoisting device 29 to lift and lower. The control device 40 controls the switch 29c, which opens and closes.

The control of the first winch 23 by the control device 40 may be either open-loop control or closed-loop control. Open-loop control means that the control device 40 controls the rotational speed and rotational acceleration of the first winch 23 without monitoring the rotational speed and rotational acceleration of the first winch 23. Closed-loop control means that the control device 40 controls the rotational speed and rotational acceleration of the first winch 23 while monitoring the rotational speed and rotational acceleration of the first winch 23 and the position of the traverse trolley 22 using a rotary encoder or the like. The control of the winches 28, 30 by the control device 40 may also be either open-loop control or closed-loop control.

The controller 41 is used to remotely control the winches 23, 28, 30 and the switch 29c. The controller 41 has input devices such as an operating lever, a foot pedal, a handle, a push button, a joystick, and a switch. When an operator operates the controller 41, the controller 41 outputs a signal according to the operation to the control device 40, and the control device 40 controls the winches 23, 28, 30 and the switch 29c according to the signal. In this way, the winches 23, 28, 30 and the switch 29c are remotely controlled. Note that the cable crane 10 is usually automatically operated by the control device 40, and an operator manually operates the cable crane 10 using the controller 41 as an auxiliary.

[4. Cable crane operation]
The operation of the cable crane 10 associated with the control device 40 controlling the winches 23, 28, 30 and the switch 29c will be described. In addition, a method of transporting ready mixed concrete as a suspended load using the cable crane 10 will be described. In addition, a method of constructing a structure 99 using the cable crane 10 will be described.

(1) Adjustment of the Transfer Location The control device 40 operates the second winch 28, whereby the traveling trolley 27 moves along the rail cable 26. As a result, the end of the main rope 21 is displaced along the rail cable 26, and the position of the transfer location P1 is adjusted along the bunker track 12. The length and tension of the main rope 21 may be appropriately adjusted according to the distance from the traveling trolley 27 to the first tower 24 by winding and unwinding the main rope 21 by the winch when the traveling trolley 27 moves.

(2) Movement of the hoisting gear to the transfer location The control device 40 operates the first winch 23, which causes the traverse trolley 22 to move along the main ropes 21 toward the mountain 91 and the traveling trolley 27. At the same time, the control device 40 operates the lifting winch 30, which causes the hoisting gear 29 to descend. Then, when the traverse trolley 22 has moved to above the transfer location P1, the control device 40 stops the first winch 23. Furthermore, when the hoisting gear 29 has descended to the transfer location P1, the control device 40 stops the lifting winch 30. The timing at which the control device 40 stops the lifting winch 30 may be simultaneous with the timing at which the control device 40 stops the first winch 23.

At this time, the transport vehicle 13 transports the ready-mix concrete from the batcher plant 11 to the transfer location P1.

(3) Transferring The control device 40 controls the switch 29c to close the switch 29c. Then, the transport vehicle 13 performs a transfer operation, so that the ready-mixed concrete is transferred from the transport vehicle 13 to the bucket 29b of the hoisting tool 29.

(4) Transportation of ready-mix concrete to destination Fig. 4 is a diagram showing the trajectory of the hoisting tool 29 when the hoisting tool 29 moves from the transfer location P1 to the destination P2. In Fig. 4, the trajectory of the hoisting tool 29 is indicated by a circle.

The destination P2 refers to the destination to which the ready-mix concrete is transported. The point P3 where the main rope 21 intersects with the transfer location P1 in a vertically upward direction is called the departure point P3. The point P4 where the main rope 21 intersects with the transfer location P2 in a vertically upward direction is called the destination P4. The positions of the transfer location P1, the destination P2, the departure point P3, and the destination P4 in the three-dimensional Cartesian coordinate system are known data determined from the design data of the structure 99, etc. In other words, the control device 40 stores in advance the XYZ coordinates of the transfer location P1, the destination P2, the departure point P3, and the destination P4.

After the ready-mixed concrete is transferred, the control device 40 accelerates the first winch 23 so as to gradually increase the rotation speed of the first winch 23, and the traverse trolley 22 moves from the departure point P3 toward the destination P4 while accelerating. The acceleration of the traverse trolley 22 during the acceleration of the traverse trolley 22 may be constant or may gradually increase with time. In addition, the control device 40 may calculate the swing angle θ [rad] and the angular velocity ω [rad/s] of the hoisting tool 29 based on the measured position of the traverse trolley 22 and the measured position of the hoisting tool 29 measured by the position measuring devices 31 and 32, and adjust the speed and acceleration of the first winch 23 based on the swing angle θ and the angular velocity ω. The adjusted speed and acceleration of the first winch 23 contribute to offsetting the swing of the hoisting tool 29. 3, the shake angle θ is an angle formed by a vertical line passing through the position detection unit 31 and a line passing through the position detection unit 31 and the position detection unit 32. The angular velocity ω is calculated by differentiating the shake angle θ with respect to time.
At the same time that the traverse trolley 22 starts to move, the control device 40 operates the lifting winch 30, thereby lifting the hoisting device 29.

When the hoisting device 29 rises close to the traverse trolley 22, the control device 40 stops the lifting winch 30. In addition, when the speed of the first winch 23 rises to a first predetermined value, the control device 40 controls the first winch 23 at a constant speed so as to maintain the rotation speed of the first winch 23 at the first predetermined value. Therefore, the traverse trolley 22 moves at a constant speed V1 [m/s]. During the constant speed movement of the traverse trolley 22, the hoisting device 29 is suspended almost vertically from the traverse trolley 22. Note that, since the acceleration of the first winch 23 and the traverse trolley 22 during the acceleration before the constant speed movement of the traverse trolley 22 was controlled by the control device 40 based on the swing angle θ and the angular velocity ω, the swing of the hoisting device 29 stops when the movement of the traverse trolley 22 switches from the accelerating movement to the constant speed movement.

While the traverse trolley 22 is moving at a constant speed, the control device 40 operates the lifting winch 30, causing the hoisting device 29 to lower.

During the constant speed movement of the traverse trolley 22, the control device 40 monitors the distance from the traverse trolley 22 to the destination P4. Specifically, each time the control device 40 obtains the measured position of the traverse trolley 22 measured by the first position measuring device 31 from the first position measuring device 31, it calculates the distance from the traverse trolley 22 to the destination P4 based on the measured position of the traverse trolley 22 and the position of the destination P4, and compares the distance with a threshold. Here, the threshold is not a fixed value, but a positive value determined from the rotation speed of the first winch 23, i.e., the speed of the traverse trolley 22, and the control device 40 calculates the threshold from the speed of the traverse trolley 22. In other words, the equation for calculating the threshold is a function of the speed of the traverse trolley 22. For example, the higher the speed of the traverse trolley 22, the higher the threshold calculated by the control device 40. Th [m] shown in FIG. 4 is the threshold value.

If the comparison shows that the distance from the traverse trolley 22 to the destination P4 does not reach the threshold value Th, the control device 40 continues the constant speed control of the first winch 23.
If the distance from the traverse trolley 22 to the destination P4 reaches the threshold value Th as a result of the comparison, the control device 40 starts deceleration control of the first winch 23. The deceleration control will be described in detail below with reference to Figs. 5 to 7. Fig. 5 is a graph showing the change in the speed V [m/s] of the traverse trolley 22. In Fig. 5, the horizontal axis represents the distance L [m] from the traverse trolley 22 to the destination P4, and the vertical axis represents the speed V of the traverse trolley 22. Fig. 6 is a graph showing the relationship between the distance L from the traverse trolley 22 to the destination P4 and the target value C [rad], and the relationship between the distance L and the swing angle θ [rad]. Fig. 7 is a graph showing the relationship between the distance L from the traverse trolley 22 to the destination P4 and the target value C [rad]. In Figs. 6 and 7, the horizontal axis represents the distance L [m] from the traverse trolley 22 to the destination P4, and the vertical axis represents the target value C and the swing angle θ.

When the distance from the traverse trolley 22 to the destination P4 reaches the threshold value Th, the control device 40 reduces the rotational speed of the first winch 23 from a first predetermined value to a second predetermined value. As a result, the speed V of the traverse trolley 22 suddenly drops from speed V1 [m/s] to speed V2 [m/s], and the hoisting device 29 and ready-mixed concrete perform a pendulum motion with the traverse trolley 22 as the fulcrum. Here, if the hoisting device 29 and ready-mixed concrete suspended from the traverse trolley 22 moving in translation are considered to be a rigid pendulum, the equation of motion of the system consisting of the traverse trolley 22 and the rigid pendulum is expressed as follows:

This equation of motion describes the relationship between the acceleration of the traverse trolley 22 and the swing angle of the rigid pendulum, so it can be seen that the swing angle of the rigid pendulum can be controlled by controlling the speed and acceleration of the traverse trolley 22. In order to control the swing angle of the rigid pendulum, i.e., the suspender 29, the control device 40 performs the following processing.

After the distance from the traverse trolley 22 to the destination P4 reaches the threshold value, the control device 40 performs the following swing angle calculation process, target value calculation process, comparison process, and deceleration adjustment process each time it acquires the measured position of the traverse trolley 22 and the measured position of the hoisting device 29 from the position measuring devices 31 and 32.

In the sway angle calculation process, the control device 40 calculates the sway angle θ [rad] of the suspending device 29 based on the measured positions of the traverse trolley 22 and the suspending device 29 measured by the position measuring devices 31 and 32. Furthermore, the control device 40 calculates the angular velocity ω by time-differentiating the sway angle θ of the suspending device 29.

In the target value calculation process, the control device 40 calculates the target value C [rad] based on the measured position of the traverse trolley 22. More specifically, the control device 40 calculates the distance from the traverse trolley 22 to the destination P4 based on the measured position of the traverse trolley 22 and the position of the destination P4, and then calculates the target value C from that distance. As shown in FIG. 6 or FIG. 7, the target value C is a positive value determined from the distance from the traverse trolley 22 to the destination P4. In other words, the equation for calculating the target value C is a function of the distance from the traverse trolley 22 to the destination P4, and the shorter the distance, the lower the target value C calculated by the control device 40. In the example shown in FIG. 6, the control device 40 calculates the target value C corresponding to the distance from the traverse trolley 22 to the destination P4 from the equation of a linear function determined by a positive proportional constant. In the example shown in FIG. 7, the control device 40 calculates the target value C, which corresponds to the distance from the traversing trolley 22 to the destination P4, from the equation of a function that draws a downward convex curve passing through the origin on a graph defined by the vertical and horizontal axes.

In the comparison process, the control device 40 compares the swing angle θ calculated in the swing angle calculation process with the target value C calculated in the target value calculation process.

In the deceleration adjustment process, the control device 40 adjusts the deceleration of the first winch 23 according to the comparison result of the comparison process. Deceleration refers to the absolute value of negative acceleration. Therefore, the greater the deceleration, the greater the amount of speed reduction per unit time.

The deceleration adjustment process will now be described in detail.
If the sway angle θ is equal to the target value C, the control device 40 reduces the rotational speed of the first winch 23 so as to maintain the deceleration of the first winch 23, so that the traverse trolley 22 translates with a uniform deceleration motion.

If the sway angle θ is greater than the target value C, the control device 40 reduces the rotational speed of the first winch 23 to reduce the deceleration of the first winch 23, and the deceleration of the traverse trolley 22 decreases. As a result, the hoisting device 29 swings so that its sway angle approaches the target value C. Note that the greater the absolute value of the difference between the sway angle θ and the target value C, the greater the amount of reduction in the deceleration of the first winch 23 that the control device 40 reduces may be.

If the sway angle θ is smaller than the target value C, the control device 40 reduces the rotational speed of the first winch 23 so as to increase the deceleration of the first winch 23, and the deceleration of the traverse trolley 22 increases. Therefore, the hoisting device 29 swings so that its sway angle approaches the target value C. Note that the greater the absolute value of the difference between the sway angle θ and the target value C, the greater the increase in the deceleration of the first winch 23 that the control device 40 increases may be.

After that, until the traverse trolley 22 reaches the destination P4, the control device 40 performs the swing angle calculation process, the target value calculation process, the comparison process, and the deceleration adjustment process each time it obtains a measured position from the position measuring devices 31 and 32.

The control device 40 may simply gradually decrease the speed of the lateral trolley 22 without performing deceleration adjustment processing from the time when the distance from the lateral trolley 22 to the destination P4 reaches the threshold value Th until the swing angle θ reaches the target value C as shown at the intersection point P in FIG. 6, or may maintain the speed of the lateral trolley 22 at the speed V2 [m/s]. Also, the control device 40 may simply gradually decrease the speed of the lateral trolley 22 without performing deceleration adjustment processing from the time when the distance from the lateral trolley 22 to the destination P4 reaches the threshold value Th until the angular velocity ω becomes zero, or may maintain the speed of the lateral trolley 22 at the speed V2 [m/s].

When the traverse trolley 22 reaches destination P4, the rotational speed of the first winch 23 becomes zero by the control device 40 as described above. Therefore, the traverse trolley 22 stops at destination P4. In addition, since the control device 40 adjusts the deceleration of the first winch 23 and therefore the deceleration of the traverse trolley 22 by the deceleration adjustment process, the swing of the hoisting device 29 also stops when the traverse trolley 22 reaches destination P4. In particular, if the equation for determining the target value C is a curved function as shown in FIG. 7, the time when the swing of the hoisting device 29 stops tends to coincide with the time when the traverse trolley 22 reaches destination P4.

As described above, the hoisting device 29 continues to descend even when the control device 40 is performing deceleration control. When the traverse trolley 22 reaches destination P4 or shortly before that, the hoisting device 29 reaches the height of destination P2, so the control device 40 stops the lifting winch 30. Therefore, when the traverse trolley 22 reaches destination P4, the hoisting device 29 also reaches destination P2.

(5) Dropping After that, the control device 40 controls the switch 29c to open the switch 29c. Therefore, the ready-mix concrete in the bucket 29b is dropped from the bucket 29b to the lower side. Alternatively, the switch 29c may be opened by an operator operating the control device 41.

(6) Return of the hoisting device to the transfer location After the ready-mix concrete has been dropped, the control device 40 accelerates the first winch 23 so as to gradually increase the rotation speed of the first winch 23, whereby the traverse trolley 22 moves from the destination P4 toward the starting point P3 while accelerating. The acceleration of the traverse trolley 22 during the acceleration of the traverse trolley 22 may be constant or may gradually increase over time.

At the same time that the traverse trolley 22 starts moving, the control device 40 activates the lifting winch 30, causing the lifting device 29 to rise.

When the hoisting device 29 rises close to the traverse trolley 22, the control device 40 stops the lifting winch 30. Also, when the speed of the first winch 23 rises to a first predetermined value, the control device 40 controls the first winch 23 at a constant speed so as to maintain the rotational speed of the first winch 23 at the first predetermined value.

When the traverse trolley 22 approaches the starting point P3, the control device 40 controls the first winch 23 to decelerate so that the rotational speed of the first winch 23 gradually decreases. Therefore, the traverse trolley 22 moves toward the starting point P3 while decelerating. The control device 40 also operates the lifting winch 30, causing the hoisting device 29 to descend.

When the traverse trolley 22 reaches the departure point P3, the control device 40 stops the first winch 23. When the traverse trolley 22 reaches the departure point P3 or shortly before, the hoisting device 29 reaches the height of the transfer location P1, so the control device 40 stops the lifting winch 30. Therefore, when the traverse trolley 22 reaches the departure point P3, the hoisting device 29 also reaches the transfer location P1.

After that, the above-mentioned "(3) transfer," "(4) transportation of the ready-mix concrete to the destination," "(5) dropping," and "(6) return of the hoist to the transfer location" are repeated, so that ready-mix concrete is transported to the valley 93 one after another and dropped.

5. Advantageous Effects
When the lateral trolley 22 moves to the destination P4, if the distance from the lateral trolley 22 to the destination P4 becomes equal to or less than the threshold value Th, the lateral trolley 22 is decelerated and the deceleration of the lateral trolley 22 is adjusted. Specifically, if the measured sway angle θ of the hoisting tool 29 is equal to the target value C, the deceleration of the lateral trolley 22 is maintained, if the sway angle θ is greater than the target value C, the deceleration of the lateral trolley 22 is decreased, and if the sway angle θ is smaller than the target value C, the deceleration of the lateral trolley 22 is increased. Therefore, even if the hoisting tool 29 descends during the deceleration of the lateral trolley 22 and the distance from the hoisting tool 29 and the center of gravity of the load to the lateral trolley 22 changes, the sway angle θ of the hoisting tool 29 converges to the target value C. Therefore, when the lateral trolley 22 reaches the destination P4, the sway of the hoisting tool 29 also stops.

As shown in Figures 6 and 7, the formula for calculating the target value C is a function of the distance from the traverse trolley 22 to the destination P4, and the target value C is calculated to be lower as the traverse trolley 22 approaches the destination P4. The deceleration of the traverse trolley 22 is adjusted according to the comparison result between the target value C and the swing angle θ, so that the swing of the hoisting device 29 stops when the traverse trolley 22 reaches the destination P4.

When the traverse trolley 22 moves to destination P4, the hoisting device 29 descends, and when the traverse trolley 22 reaches destination P4, the swinging of the hoisting device 29 stops. Therefore, immediately after the traverse trolley 22 reaches destination P4, ready-mix concrete can be dropped from the bucket 29b below it. The concrete pouring cycle is short, and the construction period of the structure 99 can be shortened.

20 Cable crane 21 Main rope 22 Traverse trolley 23 First winch (drive device)
29 Hanging device 31 First position measuring device 32 Second position measuring device 40 Control device

Claims (6)

A main rope is stretched between the peaks above a valley between the peaks;
A traverse trolley mounted on the main rope so as to move along the main rope;
A drive unit that drives the traverse trolley;
A hanging tool suspended from the traverse trolley;
a first position measuring device for measuring a position of the traverse trolley;
a second position measuring device that measures the position of the hanging device;
a control device that controls the drive device to control the speed of the traverse trolley;
When the control device decelerates the traverse trolley,
the control device calculates a swing angle of the suspending device based on the position measured by the first position measuring device and the position measured by the second position measuring device;
The control device compares the calculated swing angle of the sling tool with a target value, and if the swing angle of the sling tool is equal to the target value, the control device decelerates the traverse trolley so as to maintain the deceleration of the traverse trolley;
If the swing angle of the hoist is greater than the target value, the control device decelerates the traverse trolley so as to reduce the deceleration of the traverse trolley;
A cable crane in which, if the swing angle of the hoisting device is smaller than the target value, the control device decelerates the traverse trolley so as to increase the deceleration of the traverse trolley. The cable crane according to claim 1 , wherein the control device calculates the target value based on a distance from the position measured by the first position measuring device to a destination. The cable crane according to claim 2 , wherein the control device calculates the target value to be smaller as the distance from the position measured by the first position measuring device to the destination becomes smaller. Further provided is a lifting winch for lifting and lowering the hoisting tool,
4. The cable crane according to claim 1, wherein when the control device decelerates the traverse trolley, the control device operates the hoisting winch to lower the hoisting device. A main rope is stretched between the peaks above a valley between the peaks;
A traverse trolley mounted on the main rope so as to move along the main rope;
a hoisting tool suspended from the traverse trolley, and a load held by the hoisting tool is transported by using a cable crane, the method comprising:
When the traverse trolley is decelerated,
Measure the positions of the traverse trolley and the hoisting tool;
Calculating a swing angle of the hoisting tool based on the measured positions of the traverse trolley and the hoisting tool;
A transportation method in which, after comparing the calculated sway angle of the sling device with a target value, if the sway angle of the sling device is equal to the target value, the lateral trolley is decelerated to maintain its deceleration, if the sway angle of the sling device is greater than the target value, the lateral trolley is decelerated to reduce its deceleration, and if the sway angle of the sling device is smaller than the target value, the lateral trolley is decelerated to increase its deceleration. A construction method for constructing a structure in the valley by transporting ready mixed concrete as the suspended load to the valley using the transportation method according to claim 5.

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