JP4486763B2 - Jib crane hatch collision prevention method for grain unloader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grain unloader having a jib crane that can further swivel on a main swivel tower of the unloader, and more particularly to a hatch collision prevention method for a jib crane in a grain unloader that automates collision avoidance.
[0002]
[Prior art]
As shown in FIG. 3 (see also FIG. 4), the grain unloader has an unloader 1 for inserting an elevator section into the hold and a jib crane 2 for hanging a hook in the hold. The jib crane 2 is further provided with a sub-swivel tower (not shown) on the main swirl tower 4 for swiveling the main boom 3 of the unloader 1, and the jib 5 can be swung by the sub-swivel tower. When the main boom 3 is turned, the jib 5 is also rotated.
[0003]
The grain unloader will be described in detail with reference to FIG. 4. Reference numeral 6 denotes a traveling table that travels on rails 7 laid along the quay, and the main swivel tower 4 is provided on the traveling table 6. The main swirl tower 4 is provided with a cab 8, a support portion 9 that supports the main boom 3, a tilt member 10 that tilts the main boom 3, and the like. A sub-swivel tower 11 that supports the jib 5 in a freely undulating manner is provided adjacent to the support portion 9 of the main boom (in a circle). 12 is a hoisting wire for hoisting the jib 5, and 13 is a hoisting wire for hoisting the hook 14. Reference numeral 15 is a counterweight for achieving horizontal balance of the main boom, and 16 is an inclined member for inclining the elevator unit 17. The elevator unit 17 raises the grain sandwiched between the endless belts by rotating the pair of standing endless belts facing each other. By conveying the grain in the direction of the quay by a conveyor (not shown) in the main boom 3, the grain in the hold can be continuously unloaded.
[0004]
Usually, the unloader 1 is used exclusively for unloading, and the jib crane 2 is used for loading / unloading heavy machinery such as bulldozers into the hold. Although the manufacturer recommends that the jib crane 2 be withdrawn after the heavy equipment is carried in, the user is in a hurry to pay off the load, so the unloader 1 is often operated with the hook 14 in the hold. . Moreover, it is also possible to carry out unloading by the jib crane 2 in parallel with the operation of the unloader 1.
[0005]
An unloader equipped with such a jib crane is not found in applications other than grains, and can be said to be a structure unique to a grain unloader.
[0006]
[Problems to be solved by the invention]
In the grain unloader, it is important to pay attention to the collision between the suspended load (including only the hook 14) of the jib crane 2 and the hatch 18 when the main boom 3 is swiveled during the operation of the unloader 1. While driving the jib crane 2, it is easy for the driver to avoid a collision with the hatch 18 or a collision with the main boom 3, but when turning the main boom 3, the jib 5 is accompanied. As a result, the suspended load must be monitored closely relative to the hatch 18. Conventionally, the driver visually confirms, but the jib crane 2 may be blind, and it is difficult for the driver alone to avoid a collision between the suspended load and the hatch 18. For this reason, it was necessary to assist a supervisor on board or in the cab.
[0007]
Accordingly, an object of the present invention is to provide a method for preventing hatch collision of a jib crane in a grain unloader that solves the above problems and automates collision avoidance.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention has an elevator section at the tip of a main boom projecting onto a hatch of a ship berthed from a main slewing tower on a quay and has a jib that can be further swung on the main slewing tower. In a grain unloader having a jib crane with a hook suspended from the hook, the hatch position measured by a sensor attached to the jib crane in advance is stored at least when the main boom is swung, and the hook moves as the main boom swivels. The current position of the main boom is calculated, and the current position of the hook is compared with the position of the hatch to restrict the turning of the main boom so that the hook does not collide with the hatch.
[0009]
In order to measure the position of the hatch, the hook of the jib crane is moved to at least two corners of the hatch, and the hook hoisting position, the jib turning position, and the jib undulation position at each destination are measured by sensors, and these measurements are performed. The positions of the two corners may be obtained from the value.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
The mechanical structure of the grain unloader in FIG. 4 is as described above. In the present invention, a main boom angle sensor that detects the amount of turning of the main boom 3, and a hoisting position sensor that detects the hook hoisting position (the length from the tip of the jib 5 to the hook 14) from the feed amount of the hoisting wire 13. A jib angle sensor for detecting the turning position of the jib 5 (relative turning angle of the sub-turn tower 11 with respect to the main turning tower 4), and a undulation position for detecting the jib undulation position (the undulation angle of the jib 5) from the amount of the undulation wire 12 fed out. Sensors (not shown) are provided. The turning amount of the main boom 3 is detected as an increase / decrease amount of the turning angle of the main turning tower 4 with respect to the traveling platform 6. Here, it is assumed that the traveling platform 6 is fixed.
[0012]
When the jib crane 2 is operated, the positional relationship between the unwinding position of the hoisting wire 12 and the fulcrum position of the jib 5 is known, and the length of the jib 5 is known. The movement distance in the direction and the height direction can be calculated using the jib undulation position. Therefore, the hook hoisting position, the jib turning position, and the jib undulation position can be measured by the sensor, and the position of the hook 14 can be represented by three-dimensional position coordinates based on the jib crane from these measured values.
[0013]
Further, the positional relationship between the turning center of the main turning tower 4 and the turning center of the auxiliary turning tower 11 is known. Therefore, the current position of the hook 14 when the hook 14 moves as the main boom 3 turns can be calculated by adding the turning amount of the main boom to the three-dimensional position coordinates.
[0014]
In the present invention, a recognition push button used for storing the hatch position is provided in the cab.
[0015]
A control block diagram related to the present invention is shown in FIG. 1, and a control flowchart is shown in FIG.
[0016]
As shown in FIG. 1, the grain unloader control device of the present invention has a PLC (programmable logic controller) 22 that inputs information from each sensor 21 and allows / stops the main boom to turn automatically. Is provided. The PLC 22 has a memory for storing a hatch position obtained by hatch alignment (described later), calculates a current position of the hook 14 (current jib crane position), and calculates a distance by comparing the hatch position and the current jib crane position. It has a calculation part which performs a calculation, the calculation which compares the distance with the preset setting value, etc. The output signal of the PLC 22 includes a stop signal for stopping the turning of the main boom with respect to the control panel 23 provided in the cab, a failure display signal for instructing a failure display to the display panel 24 provided in the cab, etc. There is. Reference numeral 25 denotes a motor for turning the main turning tower.
[0017]
Hatch alignment is performed to store the hatch position as viewed from the jib crane 2 before starting the operation of the unloader 1. At this time, the turning angle of the main boom 3 with respect to the traveling platform 6 may be arbitrary. In the hatch alignment, the driver operates the jib crane, moves the hook 14 to the target two corners of the four corners of one hatch 18, and presses the recognition push button when the hook 14 comes to each destination. Push. At this time, the position coordinates of the two corners are obtained from the hook winding position, the jib turning position, and the jib undulation position, and the coordinates of each side of the hatch 18 are stored in the memory so that the coordinates of each side of the hatch 18 can be estimated from the position coordinates of the two corners. (Or the coordinates of each side are estimated and stored in the memory as hatch positions).
[0018]
Specifically, as shown in FIG. 3, it is assumed that the unloader 1 and the jib crane 2 are in the same hatch 18. Assuming that the four corner points of the hatch 18 are A, B, C, and D, if the two-dimensional horizontal coordinates are indicated for the two points A and D, a rectangle excluding the left side of the hatch 18 can be grasped on the coordinates. In the present embodiment in which the jib crane 2 is disposed on the right side of the main boom 3, the side to be subjected to collision avoidance is mainly the right side. Therefore, the hook is moved to two points A and D, and the recognition push button is pressed to store the hatch position in the memory. Accordingly, the A point coordinates obtained from the hook winding position, the jib turning position, and the jib undulation position when the hook 14 is at the A point, the hook winding position, the jib turning position, and the jib when the hook 14 is at the D point. The D point coordinates obtained from the undulation position are stored.
[0019]
After the hatch alignment, the operation of the unloader 1 can be started. It is of course possible to drive the jib crane 2. Here, it is assumed that the operation of the jib crane 2 is stopped after the heavy machinery is carried in. Therefore, the position on the jib crane reference coordinate by the hook hoisting position, the jib turning position, and the jib undulation position indicates the position where the heavy machinery is carried. Here, the case where the height of the current position of the hook 14 is not sufficiently higher than that of the hatch 18 and the collision between the suspended load and the hatch 18 is likely to occur when the main boom 3 is turned will be described. The description of the case where the height of the hook 14 is sufficiently higher than the hatch 18 and the collision between the suspended load and the hatch 18 does not occur even when the main boom 3 is turned will be omitted.
[0020]
As shown in FIG. 2, the main boom 3 is allowed to turn after the hatch alignment (step 31). When the main boom 3 is turned, the turning amount of the main boom 3 is detected by a sensor, and the current position of the hook 14 (the jib crane position in the figure) is calculated by adding the turning amount of the main boom 3 to the position on the jib crane reference coordinates by the PLC 22. ) Is recognized (step 32).
[0021]
A hatch position (for example, coordinates on the right side) is obtained from the alignment data (two corner coordinates) stored in the memory, the hatch position is compared with the recognized jib crane position, and a distance (comparison value in the figure) is obtained. (Step 33). The distance is compared with a preset set value (step 34). The set value is an allowance in consideration of the size of the suspended load suspended from the hook 14, the swing of the load, the swing of the hull, the inertia of the jib crane 2, and the like.
[0022]
If the distance is not less than the set value, the main boom turning is maintained and the jib crane position is continuously recognized.
[0023]
When the distance is less than the set value, a stop signal for stopping the turning of the main boom 3 is output to the control panel, and a failure display signal for instructing a failure display is output to the display panel (step 35). . Thereby, the turning of the main boom 3 is forcibly stopped, and the collision is avoided in advance. In response to the failure indication on the display panel, the driver performs an operation of turning the main boom in the reverse direction (step 36). Since turning in the reverse direction is permitted, the main boom turns in the reverse direction. By making a reverse turn, collision is more actively avoided.
[0024]
As described above, since the main boom 3 is turned, even if the jib 5 is rotated, it is recognized that the suspended load has approached the hatch 18 and the main boom 3 is automatically stopped, so that a collision is avoided.
[0025]
In the description of the flow in FIG. 2, it is assumed that the operation of the jib crane 2 is stopped. However, even when the jib crane 2 is in operation, the jib crane obtained from the changes in the hook winding position, the jib turning position, and the jib undulation position Of course, if the turning amount of the main boom 3 is added to the current position on the reference coordinates, the current position of the hook 14 can be recognized. Of course, even when the traveling platform 6 travels, the current position of the hook 14 can be recognized if the travel amount is taken into account.
[0026]
In the embodiment, the current position and the hatch position are described with coordinates based on the jib crane, but may be described with absolute coordinates based on the ground.
[0027]
【The invention's effect】
The present invention exhibits the following excellent effects.
[0028]
(1) Jib crane hatch collision due to human error during unloader operation can be prevented.
[0029]
(2) It is not necessary to operate the unloader after retracting the jib crane, and the working time can be shortened.
[Brief description of the drawings]
FIG. 1 is a control block diagram of a grain unloader showing an embodiment of the present invention.
FIG. 2 is a control flow chart of a grain unloader showing an embodiment of the present invention.
FIG. 3 is a plan view of a grain unloader.
FIG. 4 is a side view of a grain unloader.
[Explanation of symbols]
1 Unloader 2 Jib crane 3 Main boom 4 Main swivel tower 5 Jib 14 Hook 17 Elevator section 18 Hatch

Claims (2)

For grain having a jib crane that has an elevator part at the tip of a main boom protruding from the main swivel tower on the wharf on the hatch of a ship berthed, and a hook hanging from a jib that can further swivel on the main swivel tower At the time of turning the main boom at least in the unloader, the hatch position measured in advance by a sensor attached to the jib crane is stored, the current position due to the movement of the hook accompanying the turning of the main boom is calculated, and the current position of this hook is calculated. A method for preventing a hatch collision of a jib crane in a grain unloader, wherein the turning of the main boom is restricted so that the hook does not collide with the hatch in light of the position of the hatch.   In order to measure the position of the hatch, the hook of the jib crane is moved to at least two corners of the hatch, and the hook hoisting position, the jib turning position, and the jib undulation position at each destination are measured by sensors, and these measurements are performed. The method of preventing hatch collision of a jib crane in a grain unloader according to claim 1, wherein the positions of the two corners are obtained from the values.

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