JPH0419130B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a main fork and a sub-fork for cargo receiving that are arranged in parallel so as to simultaneously correspond to a plurality of cargo receiving sections adjacent to each other in the traveling direction of the crane on a shelf. The present invention relates to a method of controlling a traveling crane for loading and unloading a warehouse.

(Prior art and its problems) According to a crane equipped with a plurality of forks as described above, it is possible to carry out loading and unloading operations simultaneously for a plurality of cargo receiving sections adjacent to each other in the crane traveling direction of the shelf. The efficiency of unloading work can be greatly improved, but with this type of crane,
The crane position when the fork of the type corresponds to each load receiving part of the shelf is stored for each load receiving part as a count value that changes in conjunction with the travel of the crane to represent the distance traveled by the crane from the reference position. , the crane is stopped when the stored count value of the set destination cargo receiving section matches the count value that changes in conjunction with the crane's movement, and both the main and auxiliary forks are operated simultaneously. Although there is no positional shift in the crane traveling direction between the corresponding load receiving part, the load receiving part corresponding to the main fork and the secondary fork may correspond due to errors in the construction of the shelf or installation errors of both the main and sub forks. If the distance between the main and sub-forks does not match the distance between the main and sub-forks, there will be a positional shift in the crane traveling direction between the sub-forks and the corresponding cargo-receiving part. If the amount is too large, it will not be possible to safely receive and receive the cargo using the secondary fork, which may cause the cargo to collapse or fall.

(Means for Solving the Problems) The present invention proposes a control method capable of solving the conventional problems as described above. In a traveling crane for loading and unloading equipped with a main fork and a sub-fork for loading and unloading that are arranged in parallel so as to simultaneously correspond to the cargo receiving sections of the shelf, the crane position when the main fork corresponds to each cargo receiving section of the shelf. is stored in each cargo receiving section as a count value that changes in conjunction with the travel of the crane so as to represent the travel distance of the crane from the reference position, and the distance between the main and sub forks is replaced with the count value. The difference between the stored count value of the set main fork destination cargo receiving section and the stored count value of the cargo receiving section to which the sub fork corresponds is compared with the stored count value corresponding to the distance between the main and sub forks. If the difference is less than the allowable limit, both the main and sub forks are operated simultaneously while the crane is stopped at the set destination, and if the difference exceeds the allowable limit, the main fork transfers the cargo. After this, the crane position is corrected by a distance corresponding to the difference, and then the cargo is transferred by the sub-fork.

(Embodiment) An embodiment of the present invention will be described below based on the attached illustrative drawings. In FIG. A main fork 3 and a sub-fork 4, which can move in and out horizontally in the right and left directions with respect to the running direction, are arranged side by side. Reference numeral 5 denotes a shelf, which is erected along the travel path of the crane 1, and has a large number of load receiving portions 6 formed in a checkerboard pattern in a direction perpendicular to the crane travel direction, with load receiving portions 6 adjacent to each other in the crane travel direction. The distance therebetween is configured to substantially match the distance between the main fork 3 and the sub fork 4 of the crane 1.

As shown in FIG. 2, a pulse encoder 9 is interlocked with a motor 8 that drives the driving wheels 7 of the crane 1, and an addition/subtraction counter 1 that counts pulses from the pulse encoder 9.
0 is used together. This counter 10 is for obtaining a count value that changes in conjunction with the travel of the crane so as to represent the travel distance of the crane from the reference position. Add and subtract when moving backward.

The addition/subtraction counter 10 when the crane 1 is stopped at a position where the main fork 3 accurately corresponds to each load receiving part 6 of the shelf 5 when a so-called learning operation is performed before the crane 1 is used for actual loading/unloading work. The pulse count value is checked in advance for each receiving section 6 and stored in the storage section of the microcomputer 11. When performing this learning work, if the influence of the fall of the shelf 5 in the crane traveling direction is considered to be large, the main fork 3
accurately detects and stores the corresponding pulse count value at the crane stop position, and when it is considered that there is almost no influence of the falling of the shelf 5 in the crane traveling direction, the pulse count value of the corresponding crane stop position is detected and stored once for each column (each bay) of the load receiving section 6. It is sufficient to detect and store pulse count values at two crane stop positions.
Reference numeral 12 denotes a travel controller that controls the travel drive motor 8 (including a braking mechanism) in accordance with control signals from the microcomputer 11.
Further, the microcomputer 11 includes a third
As shown in the figure, the distance D between the main and sub forks 3 and 4
is set and stored as the amount of change in the count value of the addition/subtraction counter 10 when the distance D is replaced with the travel distance of the crane. That is, for example, crane 1
By moving 1mm, pulse encoder 9
If the distance D between the main and sub forks 3 and 4 is 1000 mm, the distance D is set and stored as a numerical value of 1000.

Reference numeral 13 is a main fork controller, and a motor 14 drives the main fork 3 in and out in accordance with the control signal from the microcomputer 11, the elevating and lowering position signal of the elevating carriage 2, and the in/out position signal of the main fork 3. and the motor 15 that drives the lifting carriage 2 up and down are operated to cause the main fork 3 to carry out forking for scooping up or unloading cargo. Reference numeral 16 is a sub-fork controller, and a motor 17 drives the sub-fork 4 in and out in accordance with a control signal from the microcomputer 11, a lift position signal of the elevating carriage 2, and a movement position signal of the sub-fork 4. and the motor 15 that drives the elevating carriage 2 up and down are operated to cause the auxiliary fork 4 to perform forking for scooping up or unloading cargo.

The microcomputer 11 is preprogrammed to perform the control described below. That is, when the destination receiving section 6 of the crane 1 (main fork 3) is set for the microcomputer 11, the stored numerical value corresponding to the destination receiving section 6 is searched, and this stored numerical value (i.e., the set address) and the crane The travel drive motor 8 is operated via the travel controller 12 so that the pulse count value of the addition/subtraction counter 10 (that is, the current address) that changes as the crane 1 travels is compared and the crane 1 is stopped when the two values match. is controlled. Further, in accordance with the setting of the warehousing cycle or the warehousing cycle, the lift drive motor 15 is controlled via a lift controller (not shown) in order to position the main fork 3 at the level at the start of forking with respect to the destination cargo receiving section 6. , the elevating carriage 2 is driven up and down.

With the above control, as shown in FIG. 3, the main fork 3 is placed in the correct position with respect to the crane traveling direction with respect to the set destination cargo receiving section 6A (i.e., between the center position of the cargo receiving section 6A in the crane traveling direction and the main fork 3 in the crane traveling direction). It stops in response to the state in which the direction center position coincides with the direction center position. At this time, if a simultaneous forking cycle using both the main and sub forks 3 and 4 is set as the forking cycle as shown in the flowchart of FIG.
The amount of positional deviation is calculated. That is, the position of the cargo receiving section 6B to which the sub-fork 4 corresponds is determined based on the set destination receiving section 6A, and the stored numerical value b corresponding to the corresponding cargo receiving section 6B is searched. Then, the difference (a-b) between the stored numerical value a of the destination cargo receiving section 6A to which the main fork 3 corresponds and the stored numerical value b is calculated, and furthermore, the difference (a-b) between the main and sub-forks 3 and 4 is calculated. The stored numerical value c corresponding to the distance D is compared and calculated, and the difference (a-b)-c is obtained as the amount of positional deviation of the sub fork 4.

Now suppose that one pulse is transmitted from pulse encoder 9 for every 1 mm of traveling distance of crane 1,
The stored numerical value a for the destination cargo receiving section 6A of the main fork 3 is 10000, the stored numerical value b for the corresponding cargo receiving section 6B of the secondary fork 4 is 9000, and the distance D between both the main and sub fork 3 and 4 is 980 mm. If the numerical value c is 980, the cargo receiving parts 6A, 6
The distance between them (a-b) is 1000 (1000 mm), and the amount of positional deviation (a-b)-c of the sub fork 4 is +20. That is, the sub fork 4 is
is shifted by 20 mm in the forward direction (toward the load receiving section 6A side). Also, in the above example, if the distance D between the main and sub forks 3 and 4 is 1005 mm, and therefore the stored numerical value c is 1005, then the positional deviation amount of the sub fork 4 (a-b) - c is -5. That is,
This means that the sub fork 4 is displaced by 5 mm in the backward movement direction (direction away from the load receiving part 6A) with respect to the load receiving part 6B.

The amount of positional deviation of the sub-fork 4 calculated as described above is compared with the permissible positional deviation limit (for example, ±10 mm) set in advance in the microcomputer 11, and the amount of positional deviation of the sub-fork 4 is compared with the permissible limit (for example, ±10 mm) (for example, -5 mm), the microcomputer 11 operates the main and sub fork controllers 13 and 16 to cause the main and sub forks 3 and 4 to carry out simultaneous fork for scooping or unloading. .

If the positional deviation of the secondary fork 4 exceeds the permissible limit, for example, +20 mm as described above, the microcomputer 11 operates only the main fork controller 13 to prevent the main fork 3 from scooping the cargo. Alternatively, only forking for unloading is performed, and after forking by the main fork 3 is completed, the travel controller 12 is activated to move the crane 1 in a direction that eliminates the positional deviation of the secondary fork 4, that is, in the backward movement direction. Run only 20mm of the amount. That is, the pulse count value of the addition/subtraction counter 10 indicates 10,000 (or 10,000±tolerance α), which is equal to the stored value corresponding to the load receiving section 6A, but the pulse count value of the addition/subtraction counter 10 is equal to the positional deviation amount 20. The crane 1 is moved backward to a position where the number decreases to 9980. The position correction direction of the crane 1 at this time is the positional deviation amount (a-
b) It may be determined by the ± sign of -c, that is, by determining the magnitude of (a-b) and c. When the position of the crane 1 is corrected so that the sub-fork 4 corresponds to the correct position in the crane traveling direction relative to the load receiving part 6B as shown in FIG. 4, the sub-fork controller 16 is activated and the sub-fork 4 Forklifting is carried out for scooping or unloading. Incidentally, FIGS. 3 and 4 show a state in which a load scooping fork is performed in which the load W stored in the load receiving portions 6A and 6B is scooped up by the main fork 3 and the sub-fork 4.

As shown in FIG. 5, when a single fork cycle is set instead of a simultaneous fork cycle, the crane 1 is placed at a position where the main fork 3 corresponds to the destination cargo receiving section 6A set as described above. After stopping, only the main fork controller 13 operates, and only the fork for scooping or unloading of the cargo by the main fork 3 with respect to the cargo receiving portion 6A is performed. Of course, it is also possible to perform a single forking cycle using only the secondary fork 4, but in this case, even though the object of forking is the receiving part 6B corresponding to the secondary fork 4, the destination is the primary fork 3. must be set as the corresponding load receiving section 6A, so it is desirable from the point of view of destination setting that a single fork cycle is always performed by the main fork 3.

In addition, if it is difficult to accurately move the crane 1 by a minute distance of several mm to several tens of mm in order to eliminate the positional deviation of the sub-fork 4, it is necessary to move the crane 1 by a certain distance sufficient to obtain the necessary stopping accuracy, e.g. It is also possible to move the crane 1 by several hundred mm in the position correction direction or in the opposite direction, and then move the crane 1 in the opposite direction again and control it to stop at the desired correction position.

(Operations and Effects of the Invention) As described above, according to the control method of the traveling crane for loading and unloading of the present invention, the cranes are arranged in parallel so as to simultaneously respond to a plurality of load receiving sections adjacent to each other in the traveling direction of the crane on the shelf. In a traveling crane for loading and unloading equipped with a main fork for receiving cargo and a sub-fork for receiving goods, the crane position when the main fork corresponds to each cargo receiving part of the shelf is expressed as the traveling distance of the crane from the reference position. A count value that changes in conjunction with the movement of the crane is stored for each cargo receiving section, and the distance between the main and sub-forks is replaced with the count value and stored, and the set main fork destination is stored. The difference between the stored count value of the load receiving section and the stored count value of the load receiving section to which the sub-fork corresponds, that is, the value corresponding to the distance between the main fork corresponding load receiving section and the sub-fork corresponding load receiving section, is calculated between the main and sub-forks. By comparing and calculating the stored count value corresponding to the distance, when the main fork is stopped at a position corresponding to the destination receiving section, the amount of positional deviation between the sub-fork and the receiving section to which the sub-fork corresponds is detected. Therefore, there is no need for any special hardware for detecting the amount of positional deviation, and the control means used in conventional cranes having a single fork can be used as is.

Moreover, when the deviation obtained by the comparison calculation is less than the allowable limit, both the main and sub forks are operated simultaneously while the crane is stopped at the set destination, and when the deviation exceeds the allowable limit, After the main fork only transfers the cargo, the crane position is corrected by a distance corresponding to the deviation, and then the sub-fork transfers the cargo, so the amount of positional deviation of the sub-fork in the crane traveling direction with respect to the cargo receiving part of the shelf. If the fork is zero or very small and there is no risk of danger even if forking is continued with the secondary fork, simultaneously fork at least two load receiving areas adjacent to the shelf in the crane traveling direction using both the primary and secondary forks. Although it is possible to greatly improve the efficiency of loading and unloading operations, there are situations in which the positional deviation of the secondary fork exceeds the allowable limit due to errors in the construction of the shelves and installation errors in both the main and secondary forks. First, we will perform forking only with the main fork that is not misaligned with respect to the receiving part, then correct the position of the crane to eliminate the misalignment of the sub-fork, and then proceed to a special forking cycle in which fork with the sub-fork is performed. Since the change is made automatically, there is no risk of simultaneously performing forking with both the main and sub fork in a situation where the positional deviation of the sub fork exceeds the allowable limit.
Therefore, it is possible to ensure that the main and sub-forks are always able to carry out cargo delivery safely and efficiently, and to eliminate the risk of cargo collapse or falling accidents.

In addition, as shown in Fig. 1, particularly thick supports 5 are installed at appropriate intervals in the crane traveling direction to increase shelf strength.
In the case of a shelf using a, the distance between the load receiving parts adjacent to each other in the crane traveling direction across the support column 5a is larger than the distance between the load receiving parts at other locations.
According to the control method of the present invention, even when simultaneous forking cycles are set for two load receiving sections adjacent in the crane traveling direction with the support 5a in between, the desired forking can be performed safely. . In other words, it is possible to use special shelves where the distances between adjacent load receiving parts in the crane travel direction are partially different, and even with such special shelves, simultaneous forking cycles can be performed. There are no restrictions on destination settings.

[Brief explanation of drawings]

Figure 1 is a side view showing the traveling crane for loading and unloading and the shelf, Figure 2 is a block diagram explaining the control mechanism of the crane, Figures 3 and 4 are the cargo receiving part of the shelf and the main and secondary sides on the crane side. FIG. 5, which is a diagram explaining the positional relationship with the fork, is a flowchart explaining the control procedure. 1... Traveling crane for loading and unloading, 2... Elevating carriage, 3... Main fork, 4... Sub-fork,
5... Shelf, 6, 6A, 6B... Load receiving section, 7...
Traveling drive wheel, 8... Traveling drive motor, 9
...Pulse encoder, 10...Addition/subtraction counter, 11...Microcomputer, 12...
...Travel controller, 13...Main fork controller, 14...Main fork egress/retraction drive motor, 15...Elevating/lowering drive motor, 16...
...Sub-fork controller, 17...Sub-fork egress/retraction drive motor.

Claims (1)

[Claims] 1. In a traveling crane for loading and unloading, which is equipped with a main fork and a sub-fork for loading and unloading that are arranged side by side so as to simultaneously respond to multiple load receiving sections adjacent to each other in the crane traveling direction of the shelf, each load receiving section on the shelf The crane position when the main fork corresponds to the main fork is stored for each receiving part as a count value that changes in conjunction with the movement of the crane so as to represent the distance traveled by the crane from the reference position. The distance between the two secondary forks is replaced with the above-mentioned count value and stored, and the difference between the stored count value of the set main fork destination receiving section and the stored count value of the corresponding cargo receiving section of the sub-fork is calculated as the main and sub fork. The distance between both forks is compared with the stored count value corresponding to the calculated value, and if the difference is less than the allowable limit, both the main and sub forks are activated simultaneously while the crane is stopped at the set destination, and the difference is determined to be within the allowable limit. When the limit is exceeded, the main fork only transfers the cargo, then the crane position is corrected by a distance corresponding to the difference, and then the sub-fork transfers the cargo. Method.