JPH06345212A - Elevation speed controller for stacker crane - Google Patents

Abstract

PURPOSE:To shorten the operation cycle time of a stacker crane without increasing the capacity of an elevator motor. CONSTITUTION:An elevator motor 7 for raising and lowering the elevator board of a stacker crane is driven by an inverter 10. The output of the inverter 10 is controlled by a crane controller 9. The crane controller 9 sets the max. elevator speed on the basis of the suspension weight of the elevator board which is detected by a load cell 8, so that the max. speed in the range which does not exceed the capacity of the elevator motor 7 is realized. Accordingly, the transfer time is shortened when the suspension weight is small.

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 for temporarily storing loads, and more particularly to a lifting speed control device for a stacker crane capable of shortening operation cycle time.

[0002]

2. Description of the Related Art A rack rack having a plurality of frontages arranged in a matrix and a stacker for transporting a load by moving in front of the rack rack for temporarily storing products and workpieces in a factory or a warehouse. An automated warehouse consisting of cranes is used. The stacker crane is composed of a traveling carriage that travels along a track and a lift that moves up and down along a mast that is erected on the traveling carriage. The lifting platform is equipped with a slide fork, and the slide fork transfers the load between the frontage and the loading / unloading station, and the load is carried on the slide fork while traveling and moving up and down.

[0003]

The cycle time for operating the stacker crane is determined by the time required to move the lifting platform between the frontage and the loading / unloading station. The capacity of the lifting motor for lifting the lifting platform of the stacker crane is designed to have a relationship that is substantially proportional to the lifting weight and the lifting speed within a certain range. That is, kSW≈C where k: coefficient S: lifting speed (m / min) W: hanging weight (kg) C: lifting motor capacity (kw)

Therefore, in the case of a stacker crane that handles a heavy load and therefore has a large hoisting weight, a large-capacity lifting motor is required, and if the lifting speed is to be increased, a larger capacity is required. The maximum lifting speed was set based on the suspended weight, assuming that the heaviest of the various types of load handled by the stacker crane was lifted, in order not to exceed the capacity of the lifting motor. .

Therefore, an object of the present invention is to provide an ascending / descending speed control device for a stacker crane capable of shortening the operation cycle time while suppressing the capacity of the ascending / descending motor as much as possible.

[0006]

In order to achieve the above object, the invention according to claim 1 is predetermined based on the weight detected by the weight detecting means for detecting the lifting weight of the lifting platform of the stacker crane. The lifting speed control device for the stacker crane was configured to control the lifting of the lifting platform so that the maximum lifting speed is maximized within the range of the lifting motor capacity.

According to a second aspect of the present invention, the load condition of the driver for driving the lifting motor for lifting the lifting platform of the stacker crane is detected, and the load of the driver is determined within a range that does not exceed the predetermined capacity of the lifting motor. The stacker crane hoisting speed controller was configured to control the driver so that the load is maximized.

[0008]

Since the present invention has the above-mentioned structure, it has the following effects.

In the ascending / descending speed control device of the stacker crane according to the first aspect of the present invention, the lifting weight of the ascending / descending platform of the stacker crane is detected by the weight detecting means. When the hanging weight is detected, the capacity of the lifting motor is determined in advance. Therefore, it is possible to determine the maximum maximum lifting speed that is almost inversely proportional to the hanging weight and substantially proportional to the capacity of the lifting motor. The ascending / descending speed control device controls ascending / descending of the ascending / descending table so that the maximum ascending / descending speed is maximized within a range not exceeding the capacity of the ascending / descending motor.

In the stacker crane lifting speed control device according to the second aspect of the present invention, since the load of the driver for driving the lifting motor for lifting the lifting platform of the stacker crane is determined by the lifting weight and the lifting speed. The ascending / descending speed control device detects the load state of the driver, and controls the driver so that the load is maximized within a range that does not exceed the predetermined capacity of the ascending / descending motor.

[0011]

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

(First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a lifting / lowering speed control device for a stacker crane according to the present invention, and FIG. 2 is a stacker crane to which the embodiment of FIG. 1 is applied. It is a front view which shows the outline of.

The stacker crane shown in FIG. 2 has a rail 1
A traveling trolley 2 traveling above, and a trolley 2 standing on the traveling trolley 2.
Book masts 3, 3, upper frame 4, masts 3, 3
And a lift table 5 that moves up and down. The elevating table 5 is lifted and lowered by hoisting and lowering the chains 6, 6 having one end attached to the hoisting table 5 by an elevating motor 7. A load W is placed on the lift table 5.

One end of each chain 6, 6 is attached to the lifting table 5 via the load cells 8, 8, respectively.
The load cells 8 and 8 detect the weight of the lifting platform 5 and send a signal to the crane controller 9. Crane controller 9
Controls the inverter 10 that drives the lifting motor 7.

The crane controller 9 checks the signals of the load cells 8 and 8 after the load transfer work by the forks (not shown) of the lift 5 is completed. Then, by controlling the output of the inverter 10 based on the suspended weight, the maximum lifting speed of the lifting platform 5 is determined.

For example, the weight is 600 kg or less, 600 to
800kg, 800-1000kg ... 1400-1
It is divided like 600 kg so that the inverter 10 outputs within the corresponding frequency. Of course, if the weight is light, the speed is increased, and if the weight is heavy, the speed is decreased. In that case, the frequency is set so that the load determined by the lifting weight and the lifting speed has a maximum limit that does not exceed the capacity of the lifting motor 7.

As described above, in order to make maximum use of the capacity of the lifting motor 7, the maximum lifting speed of the lifting platform 5 is changed according to the lifting weight so that a light load is fast and a heavy load is slow. Therefore, the average cycle time of the stacker crane operation can be shortened without increasing the capacity of the lifting motor 7 as compared with the conventional case in which the maximum lifting speed is set constant regardless of the hanging weight. .

(Second Embodiment) FIG. 3 is a block diagram showing the configuration of a second embodiment of the ascending / descending speed control device for a stacker crane according to the present invention.

In FIG. 3, an elevating motor 13 for elevating the elevating table is driven by an inverter 12. The operation of the inverter 12 is controlled by the crane controller 11. The load state of the inverter 12 is the lifting motor
Crane controller 11 in real time while driving 3
Be fed back to. Crane controller 11
Knows the capacity of the lifting motor 13 in advance, and controls the inverter 12 so that the load of the inverter 12 does not exceed the capacity of the lifting motor 13.

The crane controller 11 controls the output of the inverter 12 to drive the lifting motor 13 when the cycle of the lifting platform fork is completed. The elevating platform is accelerated from a stopped state and gradually increases in speed with a constant acceleration. Then, the speed of the elevating motor 13 is increased until the load of the inverter 12 becomes close to 100% of the capacity of the elevating motor 13, and the operation is performed with the speed as the maximum elevating speed. When the speed reaches a predetermined stop position, deceleration is started.

According to such a method, when the suspended weight is light, the load on the inverter 12 is also light, so that the maximum lifting speed of the elevator can be increased, and when the suspended weight is heavy, the elevator can be lifted. The maximum speed for raising and lowering is lower. Therefore, the average cycle time can be shortened without requiring a lifting motor having a large capacity.

The embodiment of the present invention has been described above.
It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be appropriately modified within the scope of the gist of the present invention.

For example, in the first embodiment, the maximum hoisting speed set according to the hoisting weight was selected, but the crane controller 9 may also obtain the hoisting maximum speed by calculation using the hoisting weight as a parameter. It is possible.

[0024]

As described above, according to the ascending / descending speed control device of the stacker crane according to the invention described in claim 1, since the ascending / descending platform of the stacker crane changes the maximum ascending / descending speed according to the size of the ascending weight, Is light,
The carrying time can be shortened as compared with the case of being heavy, and thus the average cycle time can be shortened.

According to the ascending / descending speed control device for the stacker crane of the second aspect of the present invention, the maximum ascending / descending speed is changed by the load of the driver which changes depending on the hoisting weight of the hoisting platform, so that the hoisting weight is light and the heavier is heavy. The transport time can be shortened as compared with the above, and therefore the average cycle time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of a lifting speed control device for a stacker crane according to the present invention.

FIG. 2 is a schematic front view showing a stacker crane to which the first embodiment is applied.

FIG. 3 is a block diagram showing the configuration of a second embodiment of a lifting / lowering speed control device for a stacker crane according to the present invention.

[Explanation of symbols]

 7 Lifting motor 8, 8 Load cell 9 Crane controller 10 Inverter

Claims (2)

[Claims] 1. A hoist such that a maximum hoisting speed is maximized within a range not exceeding a predetermined hoisting motor capacity based on a weight detected by a weight detecting means for detecting a hoisting weight of a hoist of a stacker crane. A lifting / lowering speed control device for a stacker crane, which controls the lifting / lowering of a platform. 2. A load state of a driver for driving a lifting motor for lifting a lifting platform of a stacker crane is detected, and the load of the driver is maximized within a range not exceeding a predetermined lifting motor capacity. A lifting / lowering speed control device for a stacker crane, which is characterized by controlling a driver.