JP3198755B2 - Stacker crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacker crane for an automatic warehouse, and more particularly to a stacker crane having a plurality of forks capable of simultaneously transporting two or more articles.

[0002]

2. Description of the Related Art As shown in FIG. 2, in a factory, a warehouse, or the like, in order to temporarily store a finished product or a semi-processed product, a shelf chain 2 composed of a plurality of shelves 1 arranged in a matrix, An automatic warehouse consisting of a stacker crane 3 running in front of the frontage of the frontage 2 is used. Stacker crane 3 in FIG.
Can deliver two goods at the same time,
It is a twin-fork type provided with two forks 7, 7 on a lift 6 so that two articles can be transported each time.

[0003]

Such a twin-fork type stacker crane 3 can transfer two articles at the same time and can transport two articles at a time. There is a case where an instruction is not always generated in units of two articles, but an instruction is issued to enter and leave only one article. In such a case, 1
If a similar work instruction is issued during the execution of the transfer operation of only one article, it is troublesome twice, the cycle time becomes longer, and the margin rate decreases.

Accordingly, an object of the present invention is to provide a stacker crane provided with a plurality of forks, which can shorten the cycle time as compared with the related art.

[0005]

Means for Solving the Problems The present invention to attain the above objects, the transfer is possible stacker crane least two articles, at least two loading positions Bas
Warehousing station with multiple buffers including buffer
, Only one of the buffers at the loading position
If goods are loaded, the loading position buffer
There is an article in a buffer other than the buffer at the loading position
Or the traveling trolley is moving
If goods are being transported to the loading station, the buffer at the loading position
The stacker waits for the warehousing process until all items are ready.
A stacker crane was provided with control means for controlling the crane.

[0006]

The present invention has the above-described structure, and has the following effects.

In the stacker crane according to the present invention, the control means of the stacker crane includes at least two
For goods receipt station having a plurality of buffer containing the buffer loading position, simultaneously transfer if the stacker crane simultaneous transfer possible two or more articles to, Sunawa
If the goods are placed in all the buffers at the loading position
The storage process is started immediately. Two stacker cranes
If it is not possible to transfer these items at the same time,
That is, any of the loading position buffers at the receiving station
If items are placed only on the
Buffer in the loading position if there is an article in a buffer other than the buffer
Is moving to the car or the trolley is
Loading goods in a relatively short time
Goods are stored in all buffers at the position, so we will store until then
Wait for processing. Otherwise, in a relatively short time
Does not have all the goods in the buffer at the loading position,
Even if all the buffers at the loading position are not
Have the stacker process the stocker crane.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in the drawings will be described below.

FIG. 1 is a diagram for explaining the operation of an embodiment of a stacker crane according to the present invention.

Referring to FIG. 1, a stacker crane 3 travels between the shelves 2 and 2, and a stocking station 4 and a stocking station 5 provided near the ends of the shelves 2 and 2, respectively.
Then, the article W is transferred between the shelves 2 and 2 on the shelf 1. The traveling trolley 8 places the article W on the entry station 4 and receives the article W from the exit station 5.

The stacker crane 3 is of a twin-fork type, and the elevator 6 of the stacker crane 3
And two forks 7, 7 as shown in FIG.
By operating the forks 7, 7 at the same time, two articles Wa, Wb can be transferred at once, and the two articles can be conveyed while being placed on the forks 7, 7, respectively.

The upper surfaces of the loading station 4 and the unloading station 5 are each formed of a roller conveyor capable of moving the article W in the direction of the arrow, and one article W is provided in each of the buffers 4a to 4d and 5a to 5d.
Can be placed. Therefore, the receiving station 4 and the unloading station 5 each have four articles W at the same time.
Can be placed.

The articles W are stored in buffers 4a and 4b of the receiving station 4 and buffers 5a and
Delivery is performed at the position of 5b. The article W placed at the position of the buffer 4d of the storage station 4 is
It moves in the direction of the arrow and is transferred to the stacker crane 3 in the buffer 4a or 4b. In addition, the stacker crane 3 is connected to the buffer 5a or 5b of the unloading station 5.
The article W which came out of the shelf 1 is placed on the
Moves to the position of the buffer 5 d and is transferred to the traveling carriage 8. The control device (not shown) of the stacker crane 3 detects the position of the article W in each buffer of each station by a sensor (not shown).

The operations of the stacker crane 3, the storage station 4, and the storage station 5 are managed by a host computer (not shown). That is, the host computer creates a schedule for the outgoing request and the incoming request, and manages the operations of the stacker crane 3, the stations 4, 5, and the traveling vehicle 8.

In the stacker crane 3 of this embodiment, two forks 7, 7 are connected to each station 4,
5 is controlled by the control device of the stacker crane so as to operate after waiting for a state where two articles can be transferred.

Specifically, at the time of retrieval, the host computer prepares a retrieval request schedule so that two articles can be retrieved, while the control device of the stacker crane responds until the retrieval station 5 becomes full, ie, Control is performed such that the unloading operation is performed until the article W is placed on all of the buffers 5a to 5d. In this case, even if the buffers 5a and 5b, which are the unloading positions, are occupied, if the buffers 5c and 5d are empty, the articles W in the buffers 5a and 5b are immediately moved to the buffers 5c and 5d to be unloaded. Since the position is empty, it is determined that two articles can be taken out, and the taking out work is performed. However, if there is only one empty space among the buffers 5a to 5d, the articles are paid out to the traveling carriage 8 in a relatively short time, so the waiting process is waited until two empty spaces.
If there is no vacancy, the retrieval process is not performed.

At the time of loading, even if the articles W are placed only on one of the buffers 4a and 4b, which are the loading positions of the loading station 4, and the loading operation is possible, the stacker crane 3 immediately performs the loading operation. To detect whether there is an article in the buffers 4c and 4d of the storage station 4 and moving to the loading position, or whether the traveling cart 8 is transporting the article to the storage station 4 or receives data from the host computer, 2 items in buffer 4 in a short time
If it is determined that the items a and b are aligned, control is performed to wait for the warehousing process until the items are aligned.

When two articles are conveyed at the same time at the time of storage, if there are adjacent empty shelves 1 in the shelf chain 2, the forks 7, 7 are operated in synchronization, and one for each of the two shelves 1. By storing two articles W at the same time, 1
Storage can be completed in the fork time of the batch.

As described above, the twin fork type stacker crane of this embodiment operates after waiting for a state where two articles can be simultaneously delivered to each of the stations 4 and 5, so that the cycle time is shortened. Can be shortened, and the margin can be increased.

The embodiments of the present invention have been described above.
It is needless to say that the present invention is not limited to the above embodiments, and can be appropriately modified and implemented within the scope of the present invention.

For example, in the illustrated embodiment, a twin-fork type stacker crane has been described, but the present invention is also applicable to a machine having three or more forks.

[0022]

According to the stacker crane according to the present invention, the cycle time of the loading / unloading process can be reduced,
It is possible to improve the margin.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an automatic warehouse system including an embodiment of a stacker crane according to the present invention.

FIG. 2 is a perspective view showing the embodiment of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 shelf 2 shelf series 3 stacker crane 4 entrance station 4a-4d buffer 5 exit station 5a-5d buffer 8 traveling cart

Claims (1)

(57) [Claims] In a stacker crane capable of transferring at least two articles, at least two loading positions are provided.
Receiving station with multiple buffers, including buffers
Only in one of the loading position buffers
If goods are loaded, the buffer at the loading position
If there is an item in a buffer other than the
Or the traveling trolley is moving to the
If goods are being transferred to the
Wait until the goods have been delivered to all
A control means for controlling the caclane is provided.
Stacker crane that.