JP3067446B2 - Pallet eccentric load detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric load detecting device for a pallet conveyed by a conveyor device or the like.

[0002]

2. Description of the Related Art The construction of an automatic warehouse using a conventional conveyor device will be described with reference to FIG. The frame-shaped shelf 1
A plurality of storage sections 2 are formed in the up-down direction and the left-right direction. Each storage section 2 is configured to support a pallet 4 on which a load 4 </ b> A is loaded via a crosspiece 3. A loading / unloading device 10 is provided in front of the shelf 1 so as to be supported and guided by a floor rail 5 and a ceiling rail 6 and run on a fixed path 7. Also,
A conveyor device 8 is installed for loading and unloading the pallets (loads) 4 to and from the automatic warehouse.
A lifter 9 is provided to face a delivery position (home position) of the pallet (load) 4 of the loading / unloading device 10.

The loading / unloading device 10 includes a lower frame 11
And a pair of front and rear posts erected from the lower frame 11
A traveling body is constituted by the upper frame 14 connecting the upper ends of the posts 12, 13 and the upper ends of the posts 12, 13;
An elevating body 15 is arranged between them. On this elevating body 15, a fork (ejecting / unloading tool) 17 which can be moved in and out of the storage section 2 and the like by the operation of a fork motor (egress / retract device) 16 is arranged.

On the lower frame 11, one post 12
Mounted on the outside of the vehicle are an elevating motor (elevation driving device) 18 interlocked with the elevating body 15 and a traveling motor (travel driving device) 19 interlocked with the driving wheels. In addition, the detector 10 is provided with a detector such as a photoelectric switch (not shown) for detecting the position of the fork 17 to be retracted.

On the delivery position (home position) side of the automatic warehouse, an operation panel (control panel) 20 for the loading / unloading device 10 is provided, and an optical data transmission device for data transmission between the operating panel 20 and the loading / unloading device 10 is provided. 21 are installed facing each other.

The conveyor device 8 is provided with a controller 22 composed of a microcomputer as a control device of the conveyor device 8, and a command signal from an operation panel (control panel) 20 of the loading / unloading device 10 and a conveyor device. The conveyor device 8 is driven and the lifter 9 is driven in accordance with a state detection signal of a sensor system such as a load detector installed in the conveyor 8.

[0007] According to this conventional type, the traveling movement on the fixed path 7 along the front surface of the shelf 1 by the loading / unloading device 10;
The combination of the elevating movement of the elevating body 15 and the lateral movement of the loading / unloading tool 17 allows the storage unit 2 of the shelf 1 and the loading / unloading device to be moved.
The transfer of the pallet (load) 4 to and from the pallet (load) 4 can be performed.
The loading / unloading device is moved by the raising / lowering movement of the
Pallet (load) 4 can be transferred between 10 and the outside.
At that time, data such as a command signal of operation of each unit between the operation panel 20 and the access device 10, a feedback signal of each unit,
The data is transmitted via the optical data transmission device 21.

[0008]

However, in the conventional configuration, when the pallet 4 is delivered by the lifter 9 of the conveyor device 8 and the loading / unloading tool 17 of the loading / unloading device 10, the loading position of the load 4A varies. When the pallet 4 is in an eccentric load state, there is a problem that the pallet 4 falls down. In addition, the pallet 4 is moved by the vibration of
There was a risk of falling or collapse of the cargo.

The present invention solves the above problems,
An object of the present invention is to provide a pallet eccentric load detecting device that detects an eccentric load state of a pallet and prevents the pallet from tipping over or collapsed.

[0010]

According to a first aspect of the present invention, there is provided a pallet eccentric load detecting apparatus for solving the above-mentioned problem, which is used when a pallet loaded with a load is delivered by an automatic warehouse loading / unloading apparatus.
To prevent the pallet from tipping over during transport.
Because, the disposed pallet delivery position of the access device, a pallet eccentric load detecting device provided in the lifter to lift vertically the pallet, the opposite end portions of the lifter, approximately the same height as the lifter upper surface The pallet is further provided with an end lower surface detecting means for which the detecting unit is set, and a judging means for judging whether or not the pallet is in an eccentric load state by the operation of the pallet end lower surface detecting means. It is assumed that.

Further, in the pallet eccentric load detecting device according to the second invention , the load is loaded by an automatic warehouse loading / unloading device .
The pallet at the time of delivery and transfer of the pallet
To prevent toppling, disposed in the pallet delivery position of said access device, said pallet comprising a pallet eccentric load detecting device provided in the lifter to lift vertically,
Pressure sensors are provided on both ends of the lifter, and a determination means is provided for determining whether the pallet is in an eccentric load state based on a variation in the level of a pressure detection signal of these pressure sensors. .

[0012]

When the pallet is lifted by the lifter and the pallet is in an eccentric load state, the lower surface of the pallet on which the load is applied is detected by the pallet end lower surface detecting means. When the pallet is detected, the determining means determines that the pallet is in the eccentric load state by the operation of the pallet end lower surface detecting means.

According to the second aspect of the present invention, when the pallet is lifted by the lifter and the pallet is in an eccentric load state, the level of the pressure detection signal of the pressure sensor varies, and the determination means It is determined that the pallet is in an eccentric load state based on the degree of this level variation.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1 is a schematic side view of a conveyor device provided with a pallet eccentric load detecting device according to one embodiment of the present invention.
FIG. 2 is a schematic plan view thereof. A mounting member 32 is protruded laterally from both ends of a pair of pallet support arms 31 of the lifter 9 disposed opposite to the transfer position with the loading / unloading device 10. Limit switch that sets the height of the detection arm 33 to the same height
34 are provided. An alarm light 35 for pallet eccentric load warning and a reset switch 36 for detecting pallet eccentric load are arranged near the lifter 9. These limit switch 34, warning light 35 and reset switch 36 are connected to the controller 22 '. In FIGS. 1 and 2,
Reference numeral 41 denotes a stopper device for stopping the pallet 4 at the transfer position with respect to the loading / unloading device 10, and reference numeral 42 denotes a chain for transporting the pallet 4. It is stretched between the driven sprockets 45. Reference numeral 46 denotes a lifting drive motor for a lifting member 47 that supports the pallet support arm 32 of the lifter 9.

As shown in FIG. 3, the controller 22 '
It comprises a conveyor / lifter control section 38 having the function of the conventional controller 22, and an eccentric load determination section 39. The eccentric load judging unit 39 receives the ON / OFF signal of the two limit switches 34 and the operation signal of the reset switch 36, and outputs a drive signal to the warning light 35 and an eccentric load detection signal to the conveyor / lifter control unit 38. doing. That is, once an ON signal of any one of the two limit switches 34 is input, an eccentric load detection signal is output to the conveyor / lifter control unit 38, and at the same time, the alarm light 35 is turned on and the two When the signal of the limit switch 34 is turned off and the operation signal of the reset switch 36 is input, the eccentric load detection signal output to the conveyor / lifter control unit 38 is reset, and the alarm lamp 35 is turned off at the same time. The conveyor lifter unit 38 lowers the lifter 9 when the eccentric load detection signal is input, and restarts the lifter 9 when the eccentric load detection signal is reset.

The operation at the time of loading the pallet 4 with the above configuration will be described. When the controller 22 'receives a pallet (load) loading command signal from the operation panel 20, the controller 22' drives the motor 43, conveys the pallet 4 by the chain 42, drives the stopper device 41, and detects the lifter 9 by the presence detector. When it is confirmed that the pallet 4 has reached the position, the motor 43 is stopped to stop the conveyance of the pallet 4, and then the lifting drive motor 46 is stopped.
Is driven upward to raise the pallet support arm 31 of the lifter 9 to support the pallet 4 with the pallet support arm 32. At this time, as shown in FIG. 4, when the pallet 4 is in an eccentric load state, the limit switch 34 on the side on which the load is applied operates, it is determined that the pallet has an eccentric load, and the lifting drive motor 46 is turned on. The pallet 4 is driven downward, the pallet support arm 32 of the lifter 9 is lowered, the pallet 4 is returned on the chain 42, and the alarm light 35 is turned on. When the operator corrects the loading position of the load 4A on the pallet 4 and operates the reset switch 36, the lifting drive motor 46 is again driven upward to raise the pallet support arm 31 of the lifter 9. And raise it to the specified height.

As described above, by returning the pallet 4 onto the chain 42 by the operation of the limit switch 34, it is possible to prevent the pallet 4 from overturning or the load 4A from collapsing. In addition, the loading / unloading device 10 can prevent the pallet 4 from overturning or the load 4A from collapsing during transportation, thereby improving the operation efficiency of the automatic warehouse and the conveyor device 8. Also, by setting the height of the detection arm 33,
An allowable value of the eccentric load of the pallet 4 can be set.

FIG. 5 shows another embodiment of the present invention. In this other embodiment, a pair of pallet support arms 31 of the lifter 9 is used instead of the mounting member 32 and the limit switch 34 of the present invention.
A load cell 37 is installed on each end of the. The pressure detection signals of these four load cells 37 are input to the eccentric load judging section 39 of the controller 22 'instead of the on / off signal of the limit switch 34.
When it is determined that the levels of the input pressure detection signals are uneven, it is determined that the pallet has an eccentric load.

As described above, by returning the pallet 4 onto the chain 42 due to the variation in the pressure detection signal of the load cell 37, it is possible to prevent the pallet 4 from overturning or the load 4A from collapsing. By this, it is possible to prevent the pallet 4 from overturning and collapsing during transport,
The operating efficiency of the automatic warehouse and the conveyor device 8 can be improved.

In the embodiment shown in FIGS. 1 to 3, the lower end of the pallet 4 is detected by a limit switch.
Although the limit switch 34 is used, instead of the limit switch 34, as shown in FIG. 6 (a), a recess 32A is provided in a mounting member 32 'projecting laterally from both ends of the pallet support arm 31. The detection rod 52 is provided on the recess 32A by an elastic body, for example, a spring body 51.
And a photoelectric switch 53 comprising a light emitter and a light receiver is provided in the recess 32A for detecting the lowering of the detection rod 52. The lower surface of the pallet 4 contacts the detection rod 52 due to the eccentric load of the pallet 4. When the detection rod 52 is lowered, the photoelectric switch 53 may be operated to detect the eccentric load. As shown in FIG. 6B, the reed switch 55 detects the descent of the detection rod 54 made of a magnetic material vertically supported by the spring body 51 on the concave portion 32A of the mounting member 32 ', and thereby the eccentricity is obtained. The load may be detected.

In this embodiment, the limit switch 34 or the load cell 37 is installed on the lifter 9.
Translator with lifter function, for example, pallet support arm
It can also be installed in a chain transformer or the like having a chain conveyor at 31. In this embodiment, a chain conveyor device is used as the conveyor device 8, but it goes without saying that another conveyor device such as a roller conveyor device may be used. The eccentric load determining unit 39 for inputting each pressure detection signal of the load cell 37 is provided with a calculation function for calculating the position of the center of gravity of the pallet 4 based on the level of each pressure detection signal of the four load cells 37. Control panel 20
, The position of the loading / unloading tool 17 at the transfer position is corrected to the input center of gravity, and the pallet 4 can be prevented from tipping over.

As described above, according to the present invention, when the pallet is lifted by the lifter, the pallet is unbalanced before the pallet is transferred to the automatic loading / unloading device by the operation of the pallet end lower surface detecting means. The pallet can be determined to be in the core load state, and
Pallet due to eccentric load of the pallet
It is possible to prevent the unit from overturning or collapse of the load .

According to the configuration of the second aspect of the present invention, the pallet is biased before delivery of the pallet to the automatic warehouse loading / unloading device due to variation in the pressure detection signal level of the pressure sensor when the pallet is lifted by the lifter. can determine that the core loading conditions, thus Palais by out device
Pallet eccentric load during delivery and transport of
It is possible to prevent the pallet from tipping over or the load from collapsing .

[Brief description of the drawings]

FIG. 1 is a schematic side view of a conveyor device provided with a pallet eccentric load detecting device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a conveyor device provided with the pallet eccentric load detection device.

FIG. 3 is a control configuration diagram of a conveyor device provided with the pallet eccentric load detection device.

FIG. 4 is an explanatory diagram for explaining an operation of the pallet eccentric load detection device.

FIG. 5 is a schematic plan view of a conveyor device provided with a pallet eccentric load detecting device according to another embodiment of the present invention.

FIG. 6 is a side view of a main part of a conveyor device provided with a pallet eccentric load detecting device according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional automatic warehouse and a conveyor device.

[Explanation of symbols]

 1 Shelf 2 Storage section 4 Pallet 4A Load 7 Constant path 8 Conveyor device 9 Lifter 10 Loading / unloading device 20 Operation panel 21 Optical data transmission device 22 'Controller 32, 32' Mounting member 34 Limit switch 35 Alarm light 36 Reset switch 37 Load cell 38 Conveyor • Lifter control unit 39 Eccentric load judgment unit (judgment means) 51 Spring body 52, 54 Detection rod 53 Photoelectric switch 55 Reed switch

Claims (2)

(57) [Claims] 1. An automatic warehouse loading / unloading device for loading a load.
When transferring and transporting the loaded pallets,
To prevent overturning of Rett, the disposed pallet delivery position of the access device, the pallet A pallet eccentric load detecting device provided in the lifter to lift vertically, the opposite ends of the lifter, the lifter An end lower surface detecting means of the pallet, the detecting portion of which is set at substantially the same height as the upper surface, is provided. A pallet eccentric load detecting device comprising: 2. Loads are loaded by an automatic warehouse loading / unloading device.
When transferring and transporting the loaded pallets,
To prevent overturning of Rett, the disposed pallet delivery position of the access device, a pallet eccentric load detecting device provided in the lifter to lift vertically the pallet, on both ends of the lifter, a pressure A pallet eccentric load detecting device, comprising: a sensor; and determining means for determining whether the pallet is in an eccentric load state based on a variation in the level of a pressure detection signal of the pressure sensor.