JP2012206825A - Method for controlling crane, and control device of the crane - Google Patents

Abstract

【Task】
When handling a container with a crane, it is possible to suppress the jumping of the rope that occurs at the moment when the container load is applied to the main wire rope, to reduce damage to the machine room, etc., and to increase the handling speed. A control method and a control apparatus thereof are provided.
[Solution]
In the control method of the crane 1 for winding the main winding wire rope 10 at a speed limit restricted by the action of the speed limiting means 13 installed on the spreader 7 and unloading the container 4, the unloading operation of the container 4 is performed by the main winding. It has a slack removing process for winding the slack of the wire rope 10 at a first speed V1 higher than the limit speed V0, and a rope tensioning process for winding the main winding wire rope 10 at a second speed V2 slower than the limit speed V0.
[Selection] Figure 1

Description

  The present invention relates to a crane control method and a control apparatus for preventing a collision between a container and a spreader during cargo handling by a quay crane, a portal crane, or the like that handles a marine transport container.

  In container terminals such as harbors and inland areas, containers between ships and trailers are loaded and unloaded by quay cranes and portal cranes.

  Fig. 5 shows an outline of a quay crane when handling. The quay crane 1 is installed on the quay 2 so as to be able to travel, and unloads the container 4 from the container ship 3. This cargo handling operation is performed by the traversing trolley 6 moving on the girder 5 moving above the container 4, lowering the spreader 7 to grasp the container 4, lifting the container 4, and transporting it to the land-side trailer 8. Is called. The spreader 7 is suspended by a main winding wire rope 10 fed out from the drum of the machine room 9. The main wire rope 10 is supported by a plurality of catenary trolleys 11.

  The catenary trolley 11 moves so as to be always located at an intermediate point between the traversing trolley 6 and the girder sea end 5a and an intermediate point between the traversing trolley 6 and the girder land end 5b. The movement of the catenary trolley 11 is configured to move along the girder 5 while supporting the main wire rope 10 at half the speed of the traversing trolley 6 (see, for example, Patent Documents 1 and 2). The catenary trolley 11 suppresses sagging of the main winding wire rope 10.

  The cab 12 is 40 to 60 m from the ground. In addition, the moving speed of the traversing trolley 6 is 200 to 300 m / min, the winding speed of the main wire rope 10 is 120 to 180 m / min when empty, 60 to 90 m / min when full, and the unwinding speed is empty. The load is 120 to 180 m / min.

  Next, an operator's crane operation in cargo handling work will be described. FIG. 6 shows a schematic diagram of the traversing trolley 6 and the spreader 7. The operator first moves the traversing trolley 6 above the container 4 in the container ship 3. The operator lowers the spreader 7 from the cab 12 while checking the position of the container 4 with the naked eye or a camera (see the left side of FIG. 6). After the spreader 7 and the container 4 are connected by the twist lock 14, the container 4 is wound up (see the right side of FIG. 6). By repeating the above, the operator performs the cargo handling operation of the container 4.

  Here, the distance from the cab 12 to the container 4 may be about 50 to 70 m, and it is difficult for the operator to confirm the position of the container 4. For this reason, the spreader 7 collides with the container 4 at a high speed, resulting in frequent accidents of landing. When the spreader 7 and the container 4 come into contact with each other, the main winding wire rope 10 is unnecessarily drawn out. As shown by the arrow A in FIG. 5, the excessively drawn main wire rope 10 is lowered by its own weight and becomes slack.

The slack of the main wire rope 10 causes damage to the machine room 9, the transverse trolley 6, the girder 5, and the like when handling the container 4. That is, the main winding wire rope 10 receives a great tension at the moment when the load of the container 4 is applied, jumps up in the direction indicated by the arrow A in FIG. Conventionally, in order to prevent destruction of the machine room 9 and the like due to this sagging, when the speed limiting means (for example, the limit switch 13) shown in FIG. In the case where it remains, the speed of winding the main wire rope 10 is automatically limited. That is, first, when the control is performed to take up the slack of the main winding wire rope 10 at a slow speed, and the limit switch 13 is turned off (inactive), the load of the container 4 is sufficiently applied to the main winding wire rope 10. Case), the speed limit is configured to be released.

  Note that the jumping of the main winding wire rope not only destroys the machine room 9 and the like, but also causes an accident in which the main winding wire rope comes off the sheave (pulley) installed in the crane. This accident in which the main wire rope is detached from the sheave takes more than a day for repair, and causes a significant drop in cargo handling efficiency.

  However, the above crane has several problems. First, there is a problem in that cargo handling efficiency decreases when control is performed to prevent destruction of a machine room or the like due to slack. That is, the slower the speed limit, the more the occurrence of the main wire rope can be suppressed, but the more time is required to take up the slack.

  Second, if priority is given to cargo handling efficiency, there is a problem that it is difficult to prevent destruction of a machine room or the like due to sagging. From the above, prevention of destruction of machine rooms due to sagging and increase in cargo handling efficiency (loading speed) are in a trade-off relationship that when one becomes better, the other worsens, and it is very difficult to improve both at the same time. There is a problem. In addition, although the speed limit at the time of control which takes a sag differs with cranes, it is often set to a speed of about 15 to 25% with respect to the full speed operation of the hoisting speed.

JP 1999-060161 A Japanese Utility Model Publication No. 63-136589

  The present invention has been made in view of the above problems, and its purpose is to suppress the rope jumping that occurs at the moment when the container load is applied to the main winding wire rope when handling the container with a crane. Another object of the present invention is to provide a crane control method and a control apparatus for the crane that can reduce damage to a machine room and the like and increase the handling speed. In addition, this invention provides the control method and its control apparatus which can be applied not only to a quay crane but to other cranes which generate | occur | produce rope jumps, such as a portal crane.

  In order to achieve the above object, a crane control method according to the present invention includes a spreader that lowers a container at the upper part of a crane that handles a marine transport container, and connects the container and the spreader. In the method of controlling a crane, which winds a wound wire rope at a speed limit limited by the action of speed limiting means installed on the spreader and unloads the container, the container unloading operation is performed by sagging the main winding wire rope. , A sag removing step of winding up at a first speed faster than the speed limit, and a rope tensioning step of winding up the main wire rope at a second speed slower than the speed limit.

  With this configuration, it is possible to suppress the main wire rope from jumping up and to improve the cargo handling efficiency. This is because the main winding wire rope is wound at a slow speed (second speed) only at the moment when a large tension is applied to the main winding wire rope (rope tension process). Further, with this configuration, the presence of slack in the main winding wire rope does not become a problem, and thus it is not necessary to install a catenary trolley on the crane. By reducing the number of parts, it is possible to reduce the weight of the crane and reduce maintenance. In addition, you may use together said control and catenary trolley.

  In the crane control method, when the spreader is lowered on the container, the first main winding wire rope when the speed limiting means installed on the spreader is brought into operation in contact with the container. A step of detecting a length, a step of detecting a second main-wound wire rope length including a length that is excessively drawn out by the downward force of the spreader, and a step of detecting the length of the first and second main-wound wire ropes And a step of calculating a sag length from the difference, wherein the sag removing step and the rope tensioning step are controlled based on the sag length.

  With this configuration, since the timing at which the container load is applied to the main winding wire rope can be accurately determined from the length of the slack, the above-described effects can be further enhanced. In other words, it is desirable to take up the slack at a high speed (first speed) and take it up at the slowest possible speed (second speed) at the moment when the container load is applied. This speed switching can be performed efficiently. it can.

  In order to achieve the above object, a crane control apparatus according to the present invention is configured to lower a spreader at an upper part of a container and to connect the container and the spreader during a cargo handling operation of a crane for handling a marine transport container. In a crane control device that winds a wound wire rope at a speed limit restricted by the action of speed limiting means installed on the spreader and unloads the container, the spreader comes into contact with the container to be in an operating state. A slack removing step comprising a speed limiting means and a slack length detection sensor for detecting a feeding length of the main wire rope, and winding the main wire rope for a slack length at a first speed equal to or higher than the speed limit. And then performing a rope tensioning step of winding the main wire rope at a second speed equal to or lower than the speed limit. And features. With this configuration, the same effects as described above can be obtained.

  Said control apparatus WHEREIN: The said slack length detection sensor has an encoder installed in the drum which pays out the main winding wire rope of the said crane. With this configuration, the same effects as described above can be obtained.

  According to the crane control method and the control device according to the present invention, the rope winding up at the moment when the container load is applied to the main winding wire rope is suppressed, the damage to the machine room and the like is reduced, and It is possible to provide a control method and a control device for a crane in which the handling speed increases.

It is the figure which showed the control flow of the crane of embodiment which concerns on this invention. It is the figure which showed control of the crane of embodiment which concerns on this invention. It is the figure which showed the control flow of the crane of embodiment which concerns on this invention. It is the figure which showed control of the crane of different embodiment which concerns on this invention. It is the figure which showed the structure of the conventional crane. It is the figure which showed the structure of the conventional traversing trolley and a spreader.

  Hereinafter, a crane control method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a control flow of the crane according to the embodiment of the present invention. FIG. 2 shows the behavior of a crane controlled by this control flow. In FIG. 2, the vertical axis represents the ratio of the winding speed of the main winding wire rope 10 to the total speed (100%), and the horizontal axis represents the elapsed winding time of the main winding wire rope 10. The solid line shows the control of the present invention, and the broken line shows the state of conventional control.

  First, after the connection between the spreader and the container is completed, the operator rotates the drum and winds up the slack of the main wire rope (S11). The acceleration operation is continued until the winding speed of the main wire rope (drum rotation speed) reaches the first speed V1 (S12). Thereafter, deceleration operation is started (S14). Here, when the slack length ΔL is large, the decelerating operation may be started after the constant speed operation (S13) is performed for a certain time. The above control is collectively referred to as a sag removing step S1.

  Next, after the winding speed of the main wire rope is reduced and reaches the second speed V2, until the speed limiting means (for example, a limit switch or the like) is not operated (OFF state) (S26), A constant speed operation is performed at the second speed V2 (S27). When the limit switch is turned off (S26), that is, after the container is hung on the main winding wire rope, the winding operation of the main winding wire rope is accelerated to full speed (S30). The above control is collectively referred to as a rope tensioning step S2.

  Here, the winding amount of the rope 10 from the start of the loading control until the limit switch is released is the slack length ΔL, and is shown by hatching in FIG. The two areas surrounded by the diagonal lines shown in FIG. 2 (the upper example shows the example of the present invention and the lower part shows the conventional example) are equal. The first speed V1 is preferably calculated from the slack length ΔL of the main winding wire rope. Furthermore, the second speed V2 is a predetermined speed, and is desirably set as a slow speed that can sufficiently suppress the jumping of the main wire rope.

  With the above configuration, the following operational effects can be obtained. First, the main wire rope can be prevented from jumping up. This is because in the rope tensioning step S2 shown in FIG. 2, the second speed V2 for winding the main wire rope is slower (smaller) than the conventional speed limit V0. That is, the winding speed of the main winding wire rope becomes the smallest at the moment when the load of the container is applied (second speed V2), so that the main winding wire rope can be prevented from jumping up.

  Second, cargo handling efficiency can be improved. This is because the first speed V1 for winding the main wire rope is faster (larger) than the conventional speed limit V0 in the sagging step S1 shown in FIG. That is, as long as the container is not loaded, the main winding wire rope is controlled to be wound at a high speed (first speed V1), so the time for handling the container can be shortened. Specifically, as shown in FIG. 2, the control of the present invention (solid line) reaches the full speed (100%) in a shorter time than the conventional control (broken line).

  Third, a crane that does not have a catenary trolley can be provided. This is because the crane handling work is not affected by the slack length ΔL by the above control. Since the crane does not have to install a catenary trolley, it is possible to realize weight reduction of the crane and reduction in maintenance by reducing the number of parts.

  FIG. 3 shows a control flow for calculating the first speed V1. When the spreader starts to descend (S01) and the spreader and the container come into contact with each other and the speed limiting means (for example, the limit switch) is activated (ON state) (S02), the length of the main wire rope is measured. And detected (S03). The length of the main winding wire rope at this time is referred to as a first main winding wire rope length. The length of the first main wire rope is equal to the distance from the drum to the container.

Next, when the limit switch signal is received, the drum is braked and finally the drum stops (S04), the length of the main wire rope is measured and detected (S05). The length of the main winding wire rope at this time is referred to as a second main winding wire rope length. This second main winding wire rope length is the length of the main winding wire rope including the length that is excessively drawn when the spreader and the container are connected.

  Next, the length of the first main winding wire rope is subtracted from the second main winding wire rope to calculate a slack length ΔL (S06). The first speed V1 is calculated from the slack length ΔL and a predetermined second speed V2 (S08). Here, the second speed V2 is read in advance (S07). Moreover, the apparatus which has said control process is named generically as a sagging length detection sensor.

  The first speed V1 can be determined by the above steps. The lengths of the first and second main winding wire ropes can be measured by, for example, an encoder installed on a drum or a traversing trolley. The determination of the first speed is not limited to the above calculation method. For example, an appropriate first speed V1 may be determined in advance from the average value of the slack length ΔL generated during the cargo handling operation and used for control.

  In FIG. 4, the graph of the control of the crane of different embodiment which concerns on this invention is shown. The crane in FIG. 4 has a step (S13) of performing a constant speed operation at a first speed V1 for a fixed time. As shown in FIG. 4, when the slack length ΔL is large, the effect of shortening the cargo handling time is particularly large. That is, the winding speed of the spreader reaches the full speed (100%) in a short time from the start of winding.

1 Crane (quay crane)
4 Container 6 Transverse trolley 7 Spreader 10 Main winding wire rope 11 Catenary trolley 13 Speed limiter (limit switch)
S1 Slack removal process S2 Rope tension process

Claims (4)

When handling a crane that handles marine transport containers, the spreader is lowered to the top of the container, the container and the spreader are connected, and the main wire rope is restricted by the action of the speed limiting means installed on the spreader. In a control method of a crane that winds up and unloads a container at a limited speed,
The unloading operation of the container includes a slack removing step of winding the slack of the main wire rope at a first speed higher than the limit speed, and a rope for winding the main wire rope at a second speed slower than the limit speed. A crane control method comprising a tensioning step. Detecting a first main wire rope length when a speed limiting means installed in the spreader comes into operation when in contact with the container when the spreader is lowered to the upper part of the container;
Detecting a second main-wound wire rope length including a length that is excessively paid out by the downward force of the spreader;
A step of calculating a slack length from a difference between the first and second main winding wire rope lengths, and controlling the slack removing step and the rope tensioning step based on the slack length. The crane control method according to claim 1. When handling a crane that handles marine transport containers, the spreader is lowered to the top of the container, the container and the spreader are connected, and the main wire rope is restricted by the action of the speed limiting means installed on the spreader. In a crane control device that winds up and unloads containers at a limited speed,
A speed limiting means that is activated when the spreader and the container come into contact with each other, and a slack length detection sensor that detects a feeding length of the main winding wire rope, and the main winding wire rope corresponding to the slack length is provided. A crane control device that performs a sag removing step of winding at a first speed equal to or higher than the speed limit, and then performs a rope tensioning step of winding the main winding wire rope at a second speed equal to or lower than the speed limit. .   The crane control device according to claim 3, wherein the slack length detection sensor has an encoder installed on a drum for feeding the main wire rope of the crane.

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