JPS6143279B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a hoisting shaft positioning device for an automatically operating crane installed in a stockyard for stacking slabs, thick plates, etc. in multiple stages. Generally, in yards where plate-shaped slabs, plate thicknesses, etc. are stocked, a crane as shown in Fig. 1 is used, and the materials are stacked in multiple stages as shown in Fig. 2. Figure 1 is an overall view of the crane, where 1 is the crane body (garter), 2 is the trolley, 3 is the hoisting device,
4 is a traversing device, 5 is a traveling device, and 6 is a hanging device, which in this example is a lifting magnet. 7
7a is a plate-shaped object to be transported, 7a is a lifted object, and 7b is a multi-layered object.
Now, the traveling device 5 moves in the X direction, the traversing device 4 moves in the Y direction, and the hoisting device 3 moves in the Z direction. FIG. 2 shows a state in which the objects 7 to be transported are stacked in multiple stages using the crane shown in FIG.
It has a position (Xi, Yj) in the Y direction and a height (Zij) in the Z direction. In such a stockyard, in order to properly manage production and logistics, the location (Xi, Yj) of the transported object 7 in the yard is
Thickness, width, length, weight of items stored there,
Management information such as specifications and height of stacked items (Zij)
etc., a yard management computer is installed to carry out the above management, and when moving the transported object 7, the command data as shown in Table 1 is sent to the automatic operation of the yard in accordance with the above management information. The control device of the crane is given to perform the work, and upon completion of the work,
The above management data is being updated. Contents of command value

[Table] Next, the crane has the configuration shown in FIGS. 3 and 4 in order to perform automatic operation in accordance with the above instructions. FIG. 3 shows an example of the equipment configuration of an automatic operation crane, in which 1 to 6 are the same as in FIG _. The stacked objects 7b have different thicknesses.
It has t ₁ , t ₂ , t ₃ , ......, and the overall height is h ₁ . Here, each sum t ₁ + t ₂ + t ₃ , ....... is h ₀
However, there is actually an error of Δh, and h ₁ = h ₀ +
There is a relationship of Δh. 10, 11, 12 are winding shafts,
A position detector for the transverse axis and the traveling axis, and the above-mentioned X, Y,
Detect the amount of movement in each direction of Z. These can be realized with synchro resolvers, shaft encoders, and proximity switches. Reference numeral 13 denotes a device for detecting the presence or absence of a suspended load. In this example, a limit switch is provided on the hanging tool 6, but a load meter may also be used. FIG. 4 is a block diagram of the control device of this crane, and numerals 3 to 5 and 10 to 12 are the same as those explained in FIGS. 1 and 3. Reference numeral 14 denotes a yard management computer, which has the functions described above and provides command data 15 to the crane control device 19. When the crane control device 19 receives this with the command receiving device 16, it gives it to the positioning control device 18 for each axis.
A position detection device 17 converts electrical signals obtained by the hoisting axis detector 10, the transverse axis detector 11, and the traveling axis detector 12 into digital quantities to obtain a position signal. In addition,
This can be omitted if each of the detectors 10 to 12 for the hoisting axis, transverse axis, and running axis can be obtained directly in digital quantities. The positioning control device 18 includes the command receiving device 1
The command value obtained in step 6 and the position signal obtained by the position detection device 17 are compared and calculated, and a direction signal and a speed signal are output to the drive control device 20. As a result, the drive control device 2
0 operates the hoisting device 3, traversing device 4, and traveling device 5, resulting in a change in position, so the position signal is constantly monitored and when the command value and the position signal match,
A work completion signal is output to the yard management computer 14. FIG. 5 is a flowchart showing the operation of the crane control device 19. That is, first, the command data 15 in Table 1 is sent from the yard management computer 14 to the crane control device 19.
The crane positions itself in the grasping position and lowers the load. At this time, the Z-axis deceleration height is calculated based on the pile height command value, and when the hanging tool 6 is lowered to an appropriate position, it decelerates and enters low-speed operation, and when the hanging tool 6 lands on the pile. The lowering is stopped, the lift magnet is attracted, and the gripping operation is performed. After this,
Wind it up to the upper limit and complete the grasping work. Next, after positioning to the lowering position, lowering is performed. At this time, the deceleration height is calculated based on the pile height command value, and when the hanging tool 6 is lowered to an appropriate position, it decelerates and enters low speed, and when the hanging tool 6 lands on the pile, it stops lowering. Then release the lift magnet and perform the lowering operation. After that, it is hoisted up to the upper limit and the unloading operation is completed. In calculating the deceleration point during lowering, the deceleration distance H _l is determined so that the hanging tool 6 can land on the floor when the lowering speed is sufficiently reduced to a low speed. In addition, detection of landing is realized by changes in the load on the hoisting shaft, a limit switch, etc. Therefore, cranes working in such stockyards are required to have accurate positioning, high-speed positioning, and high safety. In particular, when positioning the hoisting shaft, the deceleration position of the hoisting tool 6 is determined by the pile height command value as described above, so if this value differs from the actual value, the hoisting tool 6
This will cause a collision with the stack, causing damage to the hanging tool 6 and the transported object 7, which is a product. The reason for this difference is that the height stored in the yard management calculator 14 is a simple addition of the thickness of the stacked boards, and in reality, variations in board thickness, warping of the boards, and variations in the height of the ground surface are taken into account. When working alone on the crane side when the yard management computer 14 is down or the yard management computer 14 is down,
There may be cases where the data in the storage device of the yard management computer 14 is not updated. This invention attempts to eliminate the above-mentioned problems by providing a pile height storage device in the crane control device and selecting the higher value as the command value for the hoisting shaft. This invention will be explained below. FIG. 6 is a diagram showing an embodiment of the present invention.
In this figure, 21 is a storage device for the pile height Z corresponding to the position in the X and Y directions of the yard, and 22 is a command value selection device. Other symbols are the same as those in FIGS. 1 to 5. The command value selection device 22 receives the height h ₀ received by the command receiving device 16 and the pile height storage device 21
This is a device that compares and calculates the height Zij obtained by , and selects the higher value as the command value for the hoisting axis. FIGS. 7a and 7b show the detailed operation described above in a flowchart. Figure 7a shows the case of grasping work, and Figure 7b shows the case of lowering work, the command values are the values in Table 1, Zij is the height obtained by the pile height storage device 21, and H is the height at the time of positioning. The selected pile height, H _D is the deceleration height,
It is the value obtained by adding the deceleration distance H _l to the pile height H. Next, even if the height of the stack is the same, it is necessary to determine the deceleration point of the hoisting shaft during the grasping and unloading operations, taking into account the thickness t _a of the plates that can be lifted. Figures 8a and 8b show the above-mentioned conditions, with Figure 8a showing the relationship between the stack height _h1 and the lowering speed curve during the grasping operation and Figure 8b during the lowering operation. Here, ν ₀ and ν ₁ are speeds, ν ₀ >ν ₁ , and H _dL and H _du are deceleration points. In this case, the selection between grabbing and lowering is performed by the hanging load presence/absence detection device 13,
When this is not operating, it is a grasping operation, and when it is operating, it is a lowering operation, and positioning is performed by either of Fig. 8a or b. As explained in detail above, the present invention uses the larger of the pile height obtained by the pile height storage device and the pile height obtained by the command receiving device that receives commands from the yard management computer system as a command value. This makes it possible to always perform safe positioning during lowering. In addition, the present invention is equipped with a suspended load detection device, and during operation, positioning during lowering is performed based on the value obtained by adding the thickness of the transported object to the above-mentioned command value, so that the lowering speed is reduced. It has the advantage of being able to set points appropriately.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the entire crane, Fig. 2 is a perspective view showing the state of stacking of objects to be transported, Fig. 3 is a block diagram of the self-driving crane, and Fig. 4 is the self-driving crane shown in Fig. 3. 5 is a flowchart for explaining the operation of the control device in FIG. 4, FIG. 6 is a block diagram showing an embodiment of the present invention, and FIGS. 7a and 7b are Flowchart diagram for explaining the operation of Fig. 6, Fig. 8 a and b are 7
FIG. 3 is an explanatory diagram showing the operating status of the figure. In the figure, 3 is a hoisting device, 4 is a traversing device, 5 is a traveling device, 10, 11, 12 are position detectors, 13 is a suspended load detection device, 14 is a yard management computer,
15 is command data, 16 is a command receiving device, 17 is a position detection device, 18 is a positioning control device, 19 is a crane control device, 20 is a drive control device, 21
2 is a pile height storage device, and 22 is a command selection device. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a crane installed in a yard for storing plate-shaped objects to be transported stacked in multiple stages, a position corresponding to a height of the pile is stored in correspondence with the position of the stored objects to be transported. A pile height storage device, a command receiving device that receives data from a yard management computer system, and a pile height obtained by the pile height storage device and a pile height obtained by the command receiving device are compared. 1. A hoisting shaft positioning device for a crane, comprising a command selection device for selecting a larger value, and positioning at the time of lowering is performed using the value obtained by the command selection device as a command value. 2. A crane installed in a yard for storing plate-shaped transported objects stacked in multiple stages, including a position-corresponding stack height storage device that stores the stack height corresponding to the position of the stacked transported objects. A command receiving device that receives data from the yard management calculation system compares the pile height obtained by the pile height storage device with the pile height obtained by the command receiving device and selects the larger value. and a suspended load detection device that detects the suspended load of the transported object, and when the suspended load detection device is not operating, the output of the command selection device is set as a command value, and the suspended load detection device detects the suspended load of the transported object. A hoisting shaft positioning device for a crane, characterized in that when a load detection device is operating, positioning at the time of lowering is performed based on a value obtained by adding the thickness of the transported object to the command value.