JP3131429B1 - Crane runout detector - Google Patents

Abstract

An object of the present invention is to detect a swing of a crane with a simple configuration at low cost and high reliability. SOLUTION: Detection of run-out when suspending a suspended load with a spreader 2 by wires 5, 6, 7 and 8 is performed by a load cell 3 and a set of wires 5 and 6 and a set of wires 7 and 8 respectively. This is done by measuring the difference in tension between them. The wires 5 and 6 are wound around the land-end sheaves 21 and 22. The land-end sheaves 21 and 22 are connected to both ends of the chain block 27, and the middle of the chain block 27 is supported by the support sheave 25. The load cell 3 detects a force acting on the land-end sheave 22 as a tension difference between the wires 5 and 6. Load cell 4 is land-end sheave 2
4 is detected as a tension difference between the wires 7 and 8. The control device 29 includes wires 5, 6 and 7,
The shake is detected based on the tension difference of No. 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane runout detecting device for detecting a runout of a suspended load lifted by a rope in a container crane or the like.

[0002]

2. Description of the Related Art In general, a crane is used for lifting and moving a suspended load on a rope. The suspended load lifted by the cords tends to become a pendulum and cause deflection. Attempting to move the suspended load while the run-out occurs has a negative effect on operating efficiency and safety.

[0003] Today, the transport of luggage has often been carried out in standardized containers. Particularly in marine transportation, the use of container ships has become mainstream.
In a container terminal that performs cargo handling with a container ship, a container crane is used for cargo handling. 2. Description of the Related Art In recent years, in cargo handling operations using container cranes, there has been an increasing demand for restrictions on swings of suspended loads and automatic elimination of the swings for the purpose of improving the efficiency of cargo handling operations and reducing the load on operators operating the container cranes. ing. In order to suppress the swing of the suspended load with a crane, a method of detecting the swing of the suspended load and changing the cycle of the swing by changing the length of the rope to be lifted, for example, by changing the length of the rope to be lifted, is taken. . Therefore, in order to limit the swing of the suspended load,
First, it is essential to detect the swing of the suspended load.

At present, as a method for detecting a swing state of a suspended load, an accelerometer or a yaw rate gyro is used as a shake detection sensor. A camera mounted on a trolley that traverses along a girder or boom with a container crane captures an image of a target lamp mounted on a spreader that is a hanging tool, and shakes are detected by processing the captured image. As disclosed in Japanese Patent Laid-Open No. 18293/1990, the run-out is detected from the tension of the four wires that suspend the suspended load. Such techniques have been developed.

[0005]

Among the conventional methods for detecting the vibration of a suspended load, in the method described in (1), the vibration detection sensor needs to be attached to a spreader which is a hanging tool for gripping the suspended load, and adverse conditions such as an impact are required. , Durability cannot be guaranteed. In the method based on the image processing described in (1), the components are expensive, and when the camera or the target lamp becomes dirty, there is a high possibility that the target is lost. In the method of detecting the runout from the tension of the four wires shown in (1), the configuration is complicated because the tension of the four wires is directly measured. Further, since the wire load is always subjected to the hanging load, the offset is large and the difference in the wire tension caused by the runout is smaller than the hanging load, so that the resolution is low and the S / N ratio is deteriorated. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a crane runout detecting device which can detect a runout of a suspended load at low cost, with high reliability, and with easy maintenance.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a crane run-out detecting device for detecting a run-out of a suspended load by a crane that lifts a detachable lifting device by a plurality of sets of lifting ropes. A tension difference measuring means for measuring a tension difference between the lifting ropes of each set, and a deflection detecting means for detecting a deflection of a suspended load based on a tension difference between the lifting ropes measured by the tension difference measuring means; The lifting device includes a lifting rectangle, which is a virtual rectangle, and each apex position of the lifting rectangle is lifted by the lifting rope, and the lifting ropes are grouped by the apex positions of both ends of one side of the lifting rectangle. The lifting ropes form one set, and the lifting ropes at the apexes at both ends of the side opposite to the one side in the lifting rectangle form another group, and the deflection detecting means includes Tension difference between one set of lifting ropes and the other set of lifting ropes Based on the sum and difference between the tension difference of a crane shake detecting device and detects transverse vibration and swivel deflection, respectively.

According to the present invention, there is provided a crane for detecting a swing of a suspended load by a crane which lifts a detachable suspending device by a plurality of sets of lifting ropes. Means. The tension difference measuring means measures a tension difference between the lifting ropes of each set. The swing detecting means detects the swing of the suspended load based on the tension difference between the lifting ropes measured by the tension difference measuring means. Since the shake detecting means detects the shake based on the measurement result of the tension difference between the cords, the configuration is simplified compared to the case where the tension of each cord is measured and the tension difference is obtained from the measured value of the tension, Cost reduction and easy maintenance can be achieved. There is no need to attach a sensor to a hanging tool or the like, and there is no possibility that detection becomes difficult due to dirt as in the case of image processing.
Also, instead of calculating the tension difference after measuring the suspended load directly applied to the cable, the tension difference acting on each cable due to the suspended load is directly measured. Even a small difference in tension can be measured accurately, and the reliability of the detection result can be improved.

[0009]

[0010] In addition, the lifting tool is lifted at each apex position of a lifting rectangle, which is a virtual rectangle, by lifting ropes. As for the grouping of the lifting ropes, the lifting ropes at the vertices at both ends of one side of the lifting rectangle form one set, and the lifting ropes at the vertices at both ends of the side facing the one side of the lifting rectangle are the other. Form a set. The shake detecting means detects the transverse shake and the swing shake as the sum and difference between the tension difference between one set of hoisting ropes and the tension difference between the other sets of hoisting ropes. Between a pair of hoisting ropes, a large load load is applied to the hoisting rope with the larger tension, and the hoisting load becomes small on the rope in one direction in which the deflection occurs. From the sum of the two sets of measurement results, it can be seen that the hang-up load is caused to traverse to one side lifted by the rope with the smaller tension at each of the opposing sides of the lifted rectangle. From the difference between the two sets of measurement results, it can be seen that the position of the hoisting rope with the smaller load on the opposite side is diagonal, and that the swing runout has occurred.

Further, in the present invention, the crane is a container crane in which a trolley travels along a girder and a boom extending substantially in a horizontal direction, and the lifting device is lifted by the trolley via the lifting rope. A side of the lifting rectangle of the lifting tool and a pair of lifting ropes is parallel to the traveling direction of the trolley, and on the lifting tool, each apex of the lifting rectangle is provided with a lifting sheave, The trolley is a virtual rectangle, and each side is parallel to the lifting rectangle, and the length of the side parallel to the traveling direction of the trolley is:
At each apex position of the hanging rectangle longer than the length of the corresponding side of the hanging rectangle, a hanging sheave is provided,
One end of each hoisting line is fixed to the free end of the boom, and the other end is connected to a hoisting mechanism at the base end of the girder. A pair of end sheaves which are provided on the base end side of the girder and around which the two lifting ropes of each set are wound, respectively; The partial sheave is rotatably connected at both ends, and a force acting between a connecting rope supported by a rotatable supporting sheave at the middle and a supporting sheave connected by the connecting rope is measured as the tension difference. And a tension sensor for detecting the tension.

According to the present invention, the swing of the suspended load lifted by the trolley moving along the girder and the boom is bridged between the free end of the boom and the base end of the girder by the container crane. In this manner, a tension difference between the hoisting ropes can be detected at the base end side of the girder by being suspended between the hoisting sheaves of the hoisting tools via the hoisting sheave provided in the girder. At the proximal end of the girder, each lifting cable is wound around an end sheave and then connected to a hoisting mechanism, and between the end sheaves is connected by a connecting cable supported by a rotatable support sheave in the middle. You. A force corresponding to a difference in tension acting on each lifting line acts between the support sheaves connected by the connecting line, and this force can be detected by a tension sensor to measure a difference in tension. Instead of directly detecting a large hanging load, it is possible to directly detect a small difference in tension as compared with the hanging load, so that it is possible to accurately measure the difference in tension.

In the present invention, the tension sensor is a load cell, and detects a force acting between one of the pair of end sheaves and the girder.

According to the present invention, the force acting between one of the pair of end sheaves and the girder is detected by the load cell, and the tension difference between the lifting ropes wound around each end sheave can be easily determined. Can be measured. Note that a damper, a hydraulic cylinder, a spring, or the like may be provided in series with the tension sensor between one of the end sheaves and the girder.

[0015]

FIG. 1 shows a schematic configuration of a crane runout detecting apparatus according to an embodiment of the present invention. The crane runout detection device of the present embodiment detects runout in a container crane provided with a spreader 2 lifted by a trolley 1. Load cells 3 and 4 are provided for detecting shake. The load cells 3 and 4 are provided for detecting and measuring the tension difference between the pair of wires 5 and 6 as the lifting ropes of the load and the pair of wires 7 and 8, respectively.
Wires 5, 6, 7, 8 are trolley sheaves 9, 10, 11, 12, 1, which are suspension sheaves provided on trolley 1.
3, 14, 15, 16 and the spreader sheaves 17, 18, 19, 2 provided on the spreader 2, which is a lifting sheave.
0 and the spreader 2 is pulled up.

One end of the wire 5 is connected to a hoisting mechanism such as a hoisting motor at a land end sheave 21 and is stretched between the trolley sheaves 9 and 10 and the spreader sheave 17 to lift the spreader 2. The wire 6 is stretched between the trolley sheaves 11 and 12 and the spreader sheave 18 to lift the spreader 2. The wire 7 is stretched between the trolley sheaves 13 and 14 and the spreader sheave 19 to lift the spreader 2. The wire 8 is stretched between the trolley sheaves 15 and 16 and the spreader sheave 20 to lift the spreader 2. One end of each of the wires 6, 7, 8 is connected to a land sheave 22, 2 which is a support sheave.
It is wound around 3, 24 and connected to a winding mechanism. The set of land end sheaves 21 and 22 and the set of land end sheaves 23 and 24 are rotatably connected by chain blocks 27 and 28 which are rotatably wound around and supported by support sheaves 25 and 26, respectively.

The spreader 2, which is a hanging tool, can be attached to and detached from a suspended load.
A tension corresponding to the suspended load is applied to 6, 7, and 8. Since the wires 5 and 6 are wound around the land-end sheaves 21 and 22 and connected by the chain block 27, a force corresponding to the tension difference between the wires 5 and 6 acts on the land-end sheave 22, and the load cell 3 can be detected. Since the wires 7, 8 are wound around the land-end sheaves 23, 24 and connected by the chain block 28, a force corresponding to the tension difference between the wires 7, 8 acts on the land-end sheave 24, and the load cell 4 can be detected. The control device 29, according to the detection result of the force corresponding to the tension difference between the load cells 3 and 4,
It is possible to measure the lateral runout or the turning runout of the spreader 2.

FIG. 2 shows the container crane shown in FIG.
The state which lifts and transports the container 30 as a suspended load is shown. The container 30 transports the container 30 between a container yard provided at a container terminal on land and a container ship at sea. On the land side, wires 5, 6,
As the hoisting mechanism 31 for performing hoisting of 7 and 8, there are provided hoisting drums 32 and 33, a hoisting motor 34, an encoder 35, and the like. The winding drum 32 winds the wires 5 and 6 simultaneously, and the winding drum 33 winds the wires 7 and 8 simultaneously. Winding drums 32, 33
Are simultaneously driven to rotate by the winding motor 34. The rotation state of the hoisting drums 32 and 33 is detected by an encoder 35. Between the trolley 1 and the spreader 2, the trolley sheaves 9, 10, 11, 12, 13,
14, 15, 16 and spreader sheaves 17, 18, 1
Since the wires 5, 6, 7, and 8 are stretched between the trolley 1 and the lands 9 and 20, the trolley 1 is connected to the land side without changing the length of the wires 5, 6, 7, and 8 for lifting the spreader 2. You can move between the sea side. In the horizontal plane, this moving direction is defined as an x direction, a vertical direction is defined as a y direction, and a vertical direction is defined as a z direction.

FIGS. 3 and 4 show the overall shape of the container crane 40 having the configuration of FIG. In the container crane 40, the girder 41 and the boom 42 extending in the horizontal direction are supported from the ground 44 by the legs 43.
A traveling rail 45 is laid on the ground 44 in a y direction perpendicular to the x direction in which the girder 41 and the boom 42 extend, and the legs 43 can travel on the traveling rail 45. The boom 42 extends from the ground 44 in the direction of the sea 46, and loads the container 30 onto a container ship 47 anchored at the sea 46,
A cargo handling operation of unloading the loaded container 30 can be performed. In addition, the base end side of the boom 42 is connected to the tip end side of the girder 41 by a hinge pin 48, so that the stand-up state as shown by the imaginary line can be brought into a rest state.

FIG. 5 shows a state in which the spreader 2, which is a hanging tool, is lifted from the side in the y direction. Spreader 2
The distance between the trolley sheaves 9, 10; 13, 14 and the trolley sheaves 11, 12, 15 and 16 is larger than the distance in the x direction between the spreader sheaves 17, 19 and the spreader sheaves 18, 20 provided in the trolley 1. The distance is larger. For this reason, when the traversing shake shown by the imaginary line occurs, the trajectory is displaced from the natural state by the traverse shake angle θ1, and the spreader sheaves 18, 20 and the trolley sheave 1
1,12; wires stretched between 15,16,6,8
Is smaller than the tension applied to the wires 5 and 7 stretched between the spreader sheaves 17 and 19 and the trolley sheaves 9 and 10; Note that the traverse deflection angle θ1 represents the amount of angular displacement of the spreader 2 with respect to the z-axis, which is a vertical axis in the xz plane.

FIG. 6 shows the spreader 2 in plan view from the z direction. The spreader 2 may cause a swing run as indicated by a virtual line. The turning deflection angle θ2 can be represented as an angular displacement amount of the spreader 2 about the vertical axis z in the xy plane. In the turning displacement, the spreader sheaves 17, 18, 19, and 20 are lifting rectangles, which are virtual rectangles arranged at the apexes, and the directions of swinging on opposite sides are opposite. That is, on the side where the spreader sheaves 17 and 18 are both vertices, a runout toward the spreader sheave 18 which is on the positive side in the x direction occurs, and on the side where the spreader sheaves 19 and 20 are both vertices in the x direction. Swings toward the spreader sheave 19 side in the negative direction. As a result, in the swing run, the tension of the wire on the side where the run is not going is larger than the tension of the wire on the side where the run is going. That is, in the swing run-out as shown in FIG.
7 is greater than the tension. In the horizontal run-out as shown in FIG. 5, the tension of the wires 5 and 7 is larger than the tension of the wires 6 and 8.

When the spreader 2 is caused to traverse in the direction of arrow 2a in FIG. 1 due to the movement of the trolley 1, etc., as shown in FIG. 5, the tension of the wires 5, 7> the tension of the wires 6, 8 ↓ Forces in the direction of the arrows 22a and 24a in FIG. 1 are generated on the land-end sheaves 22 and 24. ↓ The load cells 3 and 4 generate forces in the order of extension forces F1a and F2a.

Similarly, when the swing runout in the direction of the arrow in FIG. 1 occurs, as shown in FIG. 6, the tension of the wires 5, 8> the tension of the wires 6,7. Forces in the directions indicated by arrows 22b and 24b in FIG. 1 are generated. ↓ The load cell 3 is subjected to an extension force F1b, and the load cell 4 is subjected to a compression force F2b.

The control device 29 shown in FIG. 1 focuses on these relationships, measures the difference in tension detected by the load cells 3 and 4, and uses F1 + F2 as an index of the lateral deflection, and F1-F2 as an index of the turning deflection. By using this, the swing of the suspended load is detected.

In this embodiment, the following effects can be expected as compared with the conventional shake detection method.

Since no image processing is performed, that is, a camera is not used, problems such as losing a target are eliminated. Since the components for shake detection are only the load cells 3 and 4 and the amplifier provided in the control device 29 of FIG. 1, the cost can be reduced. Instead of directly measuring the tension of the four wires 5, 6, 7, 8 hanging the suspended load, the tension difference between the two wires 5, 6; Since only the measurement is performed, the configuration is simplified, the S / N ratio is improved, and the resolution can be increased.

FIG. 7 shows a principle of performing a swing stop by detecting a swing of a suspended load. The applicant of the present application has already proposed in detail Japanese Patent Application No. 10-365535. The state where the container 30 is lifted by the spreader 2 can be represented by an analysis model of a one-point pendulum. In general, in the case of a one-point pendulum, the equation of motion as shown in the following first and second equations is satisfied. F = m × (L × s ² × θ0 + s ² × x) (1) F = −m × g × θ0 (2)

Where m is the mass of the pendulum, L is the length of the wire, θ0 is the deflection angle of the wire from the vertical, s is the Laplace operator, and x is the displacement in the x-axis direction. And g is the acceleration of gravity. In the second equation, the tangential component of the force generated by the mass of the pendulum is first calculated,
The approximate expression of the calculated horizontal component of the force is used. F is the horizontal force.

FIG. 8 shows the trolley 1 and the spreader 2 of this embodiment in a simplified manner from the y direction. In the case of the container crane 40 of the present embodiment, although originally a two-point pendulum as shown in FIG. 8, it can be basically handled in the same manner as a one-point pendulum when considering the force. Therefore, the following third formula is also established in the container crane 40. F = m × (L × s ² × θ 0 + s ² × x) = − m × g × θ 0 (3)

[0030] Lateral run-out can be suppressed by controlling the speed of the trolley 1. Control is performed so that the horizontal force F shown in the first to third formulas is canceled by the acceleration when the trolley 1 travels.

Turning vibration as shown in FIG. 6 can be suppressed by changing the lengths of the wires 5, 6, 7, 8 by which the hoisting mechanism 31 lifts the spreader 2 and shifting the period of the vibration. 5 can also be suppressed by changing the lengths of the wires 5, 6, 7, and 8.

In FIGS. 1 and 2, the end sheaves 22,
Although only the load cells 3 and 4 serving as tension sensors are inserted between 24 and the fixed end (girder), a hydraulic cylinder and a damper can be inserted in series with the load cells 3 and 4. Thereby, the displacement stroke can be secured.

[0033]

As described above, according to the present invention, the swing of the suspended load is detected based on the tension difference between the suspended ropes for lifting the suspended load. As compared with the configuration in which the direction of the shake is detected based on the measured value, the configuration can be simplified, the cost can be reduced, and the maintenance can be facilitated. Further, since a small difference in tension as compared with the tension applied to each lifting cable is directly measured, the deflection can be detected with high accuracy without being affected by the offset of the tension, and high reliability can be obtained.

In addition, when the lifting tool is lifted by the lifting rope at each of the vertices of the virtual lifting rectangle, it is possible to easily detect the horizontal deflection and the turning deflection.

Further, according to the present invention, a container crane lifts a suspended load from a trolley traveling along a girder and a boom, and a difference in tension between the lifting ropes is reduced by a lifting mechanism provided on a base end side of the girder. Can be done with

According to the present invention, at the base end of the girder,
The tension difference can be easily measured by the load cell between the end sheave around which one cable is wound and the girder.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a crane runout detection device as one embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a container crane that detects a run-out by the crane run-out detection device of FIG. 1;

FIG. 3 is a front view showing an external configuration of the container crane of FIG.

FIG. 4 is a side view of the container crane of FIG.

FIG. 5 is a simplified side view showing a state where the spreader 2 is lifted by the trolley 1 of FIG.

FIG. 6 is a simplified plan view of the spreader 2 suspended by the trolley 1 of FIG.

FIG. 7 is a diagram illustrating a one-point suspension pendulum.

8 is a simplified side view of the spreader 2 lifted by the trolley 1. FIG.

[Explanation of symbols]

Reference Signs List 1 trolley 2 spreader 3,4 load cell 5,6,7,8 wire 9,10,11,12,13,14,15,16 trolley sieve 17,18,19,20 spreader sieve 21,22,23,24 Sheaves 25, 26 Support sheaves 27, 28 Chain block 29 Controller 30 Container 31 Hoisting mechanism 40 Container crane 41 Girder 42 Boom

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshiteru Harada 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Akashi Plant (56) References JP-A-9-142774 (JP, A) JP-A-10-17268 (JP, A) JP-A-8-290892 (JP, A) JP-A-58-162491 (JP, A) Patent 3024966 (JP, B1) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) B66C 13 / 06,13 / 22

Claims (3)

(57) [Claims] 1. A crane run-out detecting device for detecting a run-out of a suspended load by a crane that lifts a lifting device capable of attaching and detaching a suspended load by a plurality of pairs of lifting lines. A tension difference measuring means for measuring a tension difference, and a swing detection means for detecting a swing of a suspended load based on a tension difference between the lifting ropes measured by the tension difference measuring means. Each of the vertices of the lifting rectangle, which is a virtual rectangle, is lifted by the lifting rope, respectively, and the lifting ropes are grouped into one group. The lifting rectangles are formed so that the lifting ropes at the apexes at both ends of the side facing the one side of the lifting rectangle form another set, and the deflection detecting means is provided between the lifting ropes of the one set. The sum of the difference in tension and the difference in tension between the other set of lifting ropes and Based on a crane shake detecting device and detects transverse vibration and swivel deflection, respectively. 2. The crane is a container crane in which a trolley travels along a girder and a boom extending substantially in a horizontal direction, and the lifting device is a container crane lifted by the trolley via the lifting cable. The side of the hoisting rectangle formed by the hoisting ropes is parallel to the running direction of the trolley. On the hoist, each vertex of the hoisting rectangle is provided with a sheave for hoisting. Is a virtual rectangle, each side of which is parallel to the lifting rectangle, and the length of the side parallel to the traveling direction of the trolley is longer than the length of the corresponding side of the lifting rectangle. At each apex position of the rectangle, a suspending sheave is provided.Each hoisting line has one end held at the free end of the boom, and the other end connected to the hoisting mechanism at the base end of the girder, For hanging the trolley in the middle And the tension difference measuring means is provided on the proximal end side of the girder, and a pair of two lifting ropes around which each set is wound. An end sheave, a pair of end sheaves rotatably connected to each other at both ends thereof, a connecting line supported by a rotatable support sheave at the middle, and a support sheave connected by the connecting line. The crane deflection detection device according to claim 1, further comprising a tension sensor that detects a force to be applied as the tension difference. 3. The tension sensor is a load cell,
The crane runout detecting device according to claim 2, wherein a force acting between one of the pair of end sheaves and the girder is detected.