JPH09150910A - Unloading bed device for stacker crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make safe conveyance by exactly determining a load-mounted state and detecting deviation. SOLUTION: Load cells 25A-25D for detecting load weight are placed at four corner positions for supporting a load M through a pallet 8 on an unloading bed. The weight of the load M and the center of gravity of the load M are computed from the detected values from the load cells 25A-25D. Then, determination is made whether deviation of the center of gravity against the weight of the load M is in a safety region. Provided is a safety device 22 having a control part 31 for actuating a warning device 32 when the range is out of the safety range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load carrier device for loading a load on a stacker crane in, for example, an automated warehouse.

[0002]

2. Description of the Related Art When loading or unloading an irregularly shaped load into or from a shelf by a stacker crane, if the load is unbalanced, it may drop during transportation or it may be difficult to move the load into or out of the storage space of the rack. However, conventionally, all of these have been judged by the visual inspection of the worker.

[0003]

However, there are individual differences in the judgment of the above-mentioned workers, and even if it is judged that the goods can be put in and taken out, the load may drop, and the goods can be put in and taken out. , I was sometimes reloading work in vain.

It is an object of the present invention to solve the above-mentioned problems and to provide a stacking device for a stacker crane equipped with a safety device capable of accurately determining a loaded state of a load. .

[0005]

In order to achieve the above object, the invention according to claim 1 of the present invention is a cradle capable of delivering a load to a stacker crane, and the load is applied to a plurality of positions for supporting the load. Place load cells to be detected, calculate the weight of the load and the center of gravity of the load from the detected values of these load cells, judge whether the deviation of the center of gravity with respect to the weight of the load is within the safe range, and warn when it is outside the safe range. A safety device for activating the means is provided.

According to the above construction, the safety device calculates the weight of the load and the center of gravity of the load based on the detected values of the load cells arranged at a plurality of support positions of the load, and the safe range in which the stacker crane can safely convey the load. Whether it is inside or outside, and the alarm means is activated when it is outside the safe range, it is possible to carry out loading and unloading work of the load accurately and safely without depending on the judgment of the worker.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Here, an embodiment of a stacker crane load receiving device arranged in an automatic warehouse according to the present invention will be described with reference to FIGS.

As shown in FIG. 3, this automatic warehouse has a stacker crane 2 movable on a fixed path 1 and a stacker crane 2 arranged on both sides of a traveling space 3 of the stacker crane 2. 4 having a storage space 5 for the load M, a load receiving stand device 6 placed at the end of one shelf 4 for loading the load M into and out of the shelf 4, and an operation panel 7 for operating the stacker crane 2. It has and.

As shown in FIG. 1, the stacker crane 2 has a traveling carriage 1 having a pair of front and rear elevating frames 12.
1 is movably arranged by being guided by traveling rails 13 arranged on the floor surface and the ceiling.
An elevating table 15 is arranged which can be moved up and down by an elevating drive device 14. The lifting table 15 is provided with a transfer device 16 having a fork 16a capable of transferring the load M that has been retracted into the storage space 5 of the shelf 4 and stored in the pallet 8. Reference numeral 17 is a traveling drive device for the traveling carriage 11, and 18 is a control panel.

The load receiving device 6 includes a receiving device 21 and a safety device 22.
And the pedestal 21 is provided with columns 23 that are erected at the four corners.
And the cross beams 24 that connect them to each other, the load cells 25A to 25D that are respectively arranged on the upper end support portion 23a of the support column 23 to detect the load of the pallet 8 and the load M, and the upper end support portion 23a of the support column 23. The load receiving member 26 supports the pallet 8 from below. The pallet 8 has support legs 8 at four corners of a bottom frame 8a for supporting the load M.
b is hung, and receiving guides 8c that spread in a V shape are attached to the lower ends of the support legs 8b. FIG.
As shown in, load cells 25A to 25D are arranged on the support portion 23a of the column 23 via the slide guide portion 23b. The load receiving member 26 is a cylindrical body 2 that is fitted onto the slide guide portions 23a of the columns 23 so as to be vertically movable.
6a, and the receiving guides 8c are provided at the upper end portions of the cylindrical bodies 26a.
Is attached to the support block 26b. Then, below the support block 26b, the pressure member 2 supported by the detection units of the load cells 25A to 25D.
6c is provided in a protruding manner, and the cylindrical bodies 26a are connected to each other in a rectangular shape by a connecting member 26d.

The safety device 22 includes load cells 25A-
Based on the detection signal from 25D, the total weight of the load M + pallet 8 is calculated, and the center of gravity G of the load M + pallet 8 is calculated.
And a control unit 3 for determining whether the position of the center of gravity G is within a range in which the stacker crane 2 can enter and exit the warehouse.
1 and the alarm device (warning means) 32 for notifying the worker by the warning lamp 32a and the warning buzzer 32b when the position of the center of gravity G exceeds the storage / unloading range, and the load M cannot be handled on the pedestal 21. As described above, the stop signal output device (warning means) 33 for controlling the stacker crane 2 via the operation panel 7 is configured. The warning means may be either the warning device 32 or the stop signal output device 33.

The operation of the control unit 31 will be described with reference to FIGS. If the detection value of the load cell 25A is L1, the detection value of the load cell 25B is L2, and the detection value of the load cell 25C is R1 and the detection value of the load cell 25D is R2, then the total weight is W = L1 + L2 + R1 + R2. Traveling direction of stacker crane 2 (X coordinate)
The eccentricity amount of ΔX is R1 + R2> L1 where the distance E is between the load cells 25A and 25C and between the load cells 25B and 25D.
In the case of + L2 (FIG. 4) ΔX = (R1 + R2) / W × E / 2 In the case of R1 + R2 <L1 + L2, −ΔX = (L1 + L2) / W × E / 2 Direction of the fork 16a with respect to the pallet center O (Y
The eccentricity amount (coordinates): ΔY is R2 + L2, where F is the distance F between the load cells 25A and 25B and 25C and 25D.
> R1 + L1 (Fig. 4) ΔY = (R2 + L2) / W × F / 2 R2 + L2 <R1 + L1 −ΔY = (R1 + L1) / W × F / 2 Judgment of safe range where stacker crane 2 can enter / exit As a reference, as shown in FIGS. 5 and 6, the ratio Zt% of the load M + the total weight W of the pallet 8 to the rated maximum weight and the deviation amounts ΔX and ΔY are set on the graphs in the X and Y coordinates. There is. That is, the load ratio Zt with a constant total weight W
If the total weight W is smaller than the total weight W, the larger the allowable amount is, the smaller the total weight W is. When it exceeds this, an operation signal is output to the warning device 32, and the warning lamp 32a and the warning buzzer 32 are output.
b is operated, and the stop signal output device 33 outputs a stop signal for the stacker crane 2 to the operation panel 7.

In the above structure, the load M + pallet 8 is
When carried into the pedestal 21, as shown in FIG. 7, the detection signals from the load cells 25A to 25D are taken into the control unit 31, the total load W and the eccentricity amounts ΔX and ΔY are calculated, and the eccentricity amount ΔX is then calculated. , ΔY is within the safe range SX, SY. If it is within the safe range SX, SY, the safety detection work is completed, and the eccentricity amounts ΔX, ΔY are the safe ranges SX, S.
When the vehicle departs from Y, the warning device 32 is activated to instruct the worker to transship the load M, and the load receiving operation of the stacker crane 2 is stopped.

According to the above-described embodiment, since the position shift of the load M, which conventionally relies on the visual inspection of the worker, can be automatically judged by the safety device 32, an accurate judgment can be made and the load by the stacker crane 2 can be made. It is possible to prevent accidents in which M is dropped during loading / unloading work.

The eccentricity amount of the crane 2 in the traveling direction (X coordinate): ΔX, as well as the moving direction (Y) of the fork 16a
The eccentricity amount (coordinates): ΔY is obtained to confirm the safety range, so that the deviation of the load M can be accurately detected and the safety can be further improved.

In the above embodiment, the four corner positions of the pallet 8 are detected by the load cells 25A to 25D. However, the load cells are arranged at two left and right positions or two front and rear positions to detect the load, and the crane 2 travels. It is also possible to judge the safety only by the eccentric amount: ΔX or ΔY in the direction (X coordinate) or the direction in which the fork 16a moves in and out (Y coordinate).

[0017]

As described above, according to the invention of claim 1, the safety device calculates the weight of the load and the center of gravity of the load based on the detected values of the load cells arranged at a plurality of supporting positions of the load. However, since it is judged whether it is within the safe range that can be transported by the stacker crane and the alarm means is activated when the stacker crane is out of the safe range, the loading and unloading work of the load can be performed accurately and safely without depending on the judgment of the worker.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a stacker crane load receiving device according to the present invention.

FIG. 2 is an enlarged side cross-sectional view of a supporting portion of the load receiving device.

FIG. 3 is a schematic plan view showing an automatic facility provided with the cargo cradle device.

FIG. 4 is an explanatory view for explaining the operation of the safety device of the cargo cradle device.

FIG. 5 is a graph showing a safe range of the X coordinate in the safety device of the same cargo cradle device.

FIG. 6 is a graph showing a safe range of a Y coordinate in the safety device of the load receiving device.

FIG. 7 is a flowchart showing an operation procedure of a safety device of the same cargo cradle device.

[Explanation of symbols]

 2 Stacker crane 4 Shelf 5 Storage space 6 Pallet receiving device 8 Pallet 21 Cradle 22 Safety device 23 Strut 23a Support part 25A-25D Load cell 31 Control part 32 Warning device 32a Warning lamp 32b Warning buzzer 33 Stop signal output device

Claims (3)

[Claims] 1. A cradle capable of transferring a load to a stacker crane, wherein load cells for detecting the load are arranged at a plurality of positions for supporting the load, and the weight of the load and the position of the center of gravity of the load are determined from the detected values of these load cells. A stacking device for a stacker crane, which is provided with a safety device that calculates and determines whether the amount of deviation of the center of gravity with respect to the weight of the load is within the safe range, and that activates a warning means when it is outside the safe range. 2. The load receiving device for a stacker crane according to claim 1, wherein load cells are arranged at four corners of a pallet for storing a load. 3. The stacker crane load carrier device according to claim 1, wherein the warning means is a stop signal output device for stopping the load receiving operation of the stacker crane.