JPH0527438Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a device that automatically separates pallets stacked in multiple stages one by one.

2. Description of the Related Art In many cases, empty pallets are delivered to a product loading device in a state where they are stacked in two to four tiers. Therefore, these stacked pallets must be separated one by one using a separating device before being sent to the product loading section. Therefore, in the past, stacked pallets have been separated by an automatic stacking device installed upstream of a conveyor or other transport device that transports the pallets to the product loading section and near the pallet loading position.

This conventional automatic unpacking device, for example, advances a fork between the first and second stages of pallets stacked in multiple stages on a stopped conveyor. After inserting and raising the pallets, the first pallet is left on the conveyor and the second and higher pallets are lifted up, and the conveyor is driven to remove the first pallet left on the conveyor. Transport to product loading section. Next, the conveyor is stopped, the fork is lowered, and the second stage pallet is placed on the conveyor so as to be the lowest stage, and
After the fork is retracted and extracted from the underside of the lowermost pallet, the fork is raised and returned to the operating origin. By automatically repeating the above operations, the pallets stacked in multiple tiers are automatically separated from the tiers starting from the lower tier.

On the other hand, when stacking pallets, each pallet has a height error, and there is also variation in the size of the gap between the first and second pallets, so it is difficult to keep the height of the forks constant. If the setting is set to In addition to sorting out and eliminating in advance pallets with large height errors, an optical sensor such as a reflective photoelectric sensor is provided at the tip of the fork to detect a positional deviation between the fork and the pallet. , detects the positional deviation between the fork height when inserting the fork and the height between the pallets, and if a positional deviation due to an error in the pallet height is detected,
The system stops the forward movement of the fork and issues an alarm to notify the operator of the occurrence of an abnormality in the step-opening operation. When the above-mentioned alarm etc. is issued, a worker selects and removes defective pallets.

Problems to be Solved by the Invention However, in the case of the above-mentioned conventional automatic pallet unwinding device, an optical sensor such as a reflective photoelectric sensor is attached to the tip of the fork, and this optical sensor is used to detect the difference between the pallets into which the fork is inserted. 〓Although it is designed to detect the positional deviation between the pallets, there is a risk of malfunction if the light reflecting surface of the pallet becomes dirty with oil or if oil adheres to the light receiving part or the light emitting part of the optical sensor. At the same time, if the height of the fork deviates even slightly, an alarm is issued, and it is necessary to sort out and remove defective pallets each time.

This idea was created in view of the above problems.
It operates accurately without malfunction even if the pallet is contaminated with oil or the like, or if oil or the like adheres to the sensor part, and it can also search for gaps between pallets when there is a deviation in the height direction of the fork. The object of the present invention is to provide a stacking pallet stacking device that automatically moves forks to a height where they can be inserted.

Means for Solving the Problems As a means for solving the above-mentioned problems, this invention proposes a fork that can be driven forward and backward and raised and lowered by a drive mechanism, and is moved forward from its operating point to move between stacked pallets. In an automatic stacking pallet unpacking device, the fork is inserted between the forks and lifted up, leaving a predetermined number of tiers of pallets, and then lifting the pallets stacked on the upper tiers and unpacking them sequentially from the lower tier. A touch sensor is provided at the tip to detect a positional deviation when the fork is advanced at a reference height and comes into contact with a pallet, and when the touch sensor detects the positional deviation, the fork is moved back to the operating origin,
and a control device for controlling the drive mechanism so that the fork is raised or lowered by a predetermined amount and then moved forward again until the fork is inserted between the pallets or repeatedly a predetermined number of times; The present invention is characterized in that it includes a carrying-out means for carrying out the pallet remaining below the lifted pallet from below the pallet lifted by the fork.

Operation By configuring as described above, the fork, which is driven forward and backward and up and down by the drive mechanism, can be
After advancing the fork from the operating origin and inserting it between the first and second pallets of multiple stacked pallets, the fork is raised and the pallet is placed in the second layer, leaving the first pallet behind. Lift up more pallets. Then, the remaining pallets of the first stage are sent to a product loading section etc. by the unloading means, and when there is space below the forks to unload the pallets, the forks are lowered and the pallets of the second stage are placed at the bottom stage. At the same time, the fork is moved back and removed from the underside of the lowermost pallet, and then the fork is raised to return to the operating origin. Here, the reference height of the operating origin is set for each of the various pallets to be handled.

Then, when the fork is advanced from the operating point and inserted into a predetermined gap between pallets, the touch sensor provided at the tip of the advancing fork contacts the pallet due to an incorrect height of the pallet, causing the pallet to be misaligned. Upon detection, the forward movement of the fork is stopped, the fork is once moved back to the operating origin, and after the height of the fork is changed upward or downward by a predetermined amount, the fork is moved forward again. If the fork that has been moved forward again moves forward without touching the touch sensor to the pallet, it will advance to the forward limit and then be raised to lift the second and higher pallets, and the first pallet will be moved by the unloading means. possible. In addition, when the fork is moved forward again, if the touch sensor provided on the fork contacts the pallet again and detects a positional shift, the fork is stopped from advancing and is moved back to the fork retraction limit again, and the height of the fork is increased. After changing the fork downward or upward by a predetermined amount in the opposite direction from the previous time, the fork is moved forward and the operation of searching for the height between the pallets into which the fork should be inserted is performed again.
If the gap between pallets cannot be searched by the time the predetermined number of search operations are completed, an alarm or the like is issued to notify the operator of the occurrence of an abnormality in the unpacking operation.

Embodiment Hereinafter, an embodiment of the automatic stacking pallet stacking apparatus of this invention will be described with reference to FIGS. 1 and 2.

1 pallet P stacked in multiple stages
Stack unwinding device 1 that automatically unrolls tiers one by one
is a mast 3 installed almost vertically on a truck 2.
A fork 4, which is a loading device, is provided on the mast 3 via a lift bracket 4a so as to be able to move up and down; and a drive cylinder 5, which moves the truck 2 forward and backward in the horizontal direction together with the mast 3 and fork 4.
It is equipped with The fork 4 is connected via the lift bracket 4a to a chain 7 that is wound between a drive sprocket 6a of a drive motor 6 provided at the bottom of the mast 3 and a driven sprocket 6b provided at the top of the mast 3. and is driven up and down along the mast 3 by the chain 7 which is wound around the drive motor 6 and driven.

Furthermore, a touch sensor 8 is provided at the tip of the fork 4. This touch sensor 8 has two terminals spaced apart from each other, and one of the two terminals is attached to the tip of a fork by connecting it to a pin or plate while being insulated from the fork body. The other terminal side is electrically connected to the equipment main body (conveyor 9). When the fork 4 and the pallet interfere, the current applied to the one terminal flows to the pallet P via the pin or plate at the tip of the fork 4, and from this pallet P via the conveyor 9 (equipment main body). The current flows to the other terminal, and this touch sensor 8 detects the current and turns on, thereby detecting interference between the fork 4 and the pallet P. As a result, the necessity of performing an interval search by changing the height of the fork 4 is detected. Although not shown, it is equipped with a control device that controls the forward and backward drive by the drive cylinder 5 and the up-and-down drive by the drive motor 6. It is disposed near the loading position of the pallet P on the upstream side of the conveyor 9 so as to move forward and backward in a direction perpendicular to the conveyor 9 when driven by the drive cylinder 5.

Further, the control device is equipped with a control program programmed to cause the stack unwinding device 1 to perform each operation shown in the flowchart of FIG. Each process of the unbundling operation will be explained with reference to the flowchart of FIG.

In addition, in the standby state of the stack separating device 1,
The truck 2 is located at the origin of movement, which is the backward limit, and the fork 4 is located at the movement origin, which is the backward limit.
The touch sensor 8 contacts the pallet P and performs a _search operation. When detecting _the necessity _of
A trial operating point H ₂ that is lower than the reference point H ₀ by a predetermined amount
The controller is controlled to perform two inter-interval search operations, including the second inter-interval search performed by moving to .

Now, when the three pallets P ₁ , P ₂ , and P ₃ are brought in in a stacked state of three tiers and placed at a predetermined position on the stopped conveyor 9, the control device starts disassembling the tiers. The switch is turned on.

When the switch to start stack unwinding is turned on, the control program starts. First, in step 1, it is checked whether the trolley 2 of the stack unrolling device 1 is located at the operating origin. If so, proceed to step 2.

In step 2, the truck 2 is driven forward by supplying working fluid to the forward drive side of the drive cylinder 5, and the fork 4 located at the reference point H ₀ on the mast 3 on the truck 2 is moved one step. It is inserted almost horizontally between the first pallet _P1 and the second pallet _P2 (movement indicated by the broken line arrow A in FIG. 1).

Then, in step 3, the fork 4 is inserted without interfering with the pallets P ₁ and P ₂ during the insertion process into the gap, and when the truck 2 reaches its forward limit, the supply of working fluid to the drive cylinder 5 is stopped. Stop and proceed to step 4.

Proceeding to step 4, the drive motor 6 is started, and the fork 4 is driven upward via the chain 7, leaving the first stage pallet _P1 on the conveyor 9, and the second stage pallet P2 _and this. The third layer of pallets P ₃ stacked above the fork 4
When loaded on top and lifted to a specified height (first
The operation indicated by the broken arrow B in the figure) causes the drive motor 6 to stop and the process proceeds to step 5.

When proceeding to step 5, the operation of the conveyor 9 is started and the pallet _P1 is conveyed to the product loading section, and when the pallet _P1 is conveyed to a predetermined position, the operation of the conveyor 9 is stopped and the operation proceeds to step 6. .

In step 6, the pallets below the fork 4 loaded with pallets P ₂ and P ₃ are
The presence or absence of pallet P ₁ is checked, and if there is no pallet P ₁ below fork 4, the process proceeds to step 7.

Proceeding to step 7, the drive motor 6 is activated to lower the fork 4 connected to the chain 7, and the fork 4 is lowered to a predetermined height so that the lower end of the loaded pallet _P2 is placed on the conveyor 9. When it is mounted (the action indicated by the broken line arrow C in FIG. 1), the drive motor 6 is stopped and the process proceeds to step 8.

Proceeding to step 8, working fluid is supplied to the backward driving side of the drive cylinder 5 to drive the truck 2 backward, and the fork 4 moves backward together with the truck 2, slips out from under the pallet P ₂ , and returns ( When the truck 2 returns to the operation origin, which is the backward limit (as indicated by the broken line arrow D in FIG. is raised to the reference point _H0 (the action indicated by the broken line arrow E in FIG. 1), and the process proceeds to step 9, where the step unwinding device 1 enters a standby state and the drive motor 6 stops.

After returning to the standby state in step 9, the stack unwinding device 1 repeats each process from step 1 to step 9, with the topmost pallet _P3 being placed on the conveyor 9 when the stacked pallets are carried in. Repeat the step-breaking operation until there are no overlapping pallets.

Furthermore, if it is checked that the carriage 2 is not located at the operating origin as a result of the position check of the carriage 2 carried out in step 1, the process directly proceeds to step 9 without passing through steps 2 to 8. , the truck 2 is restarted after performing an operation to return it to the operating origin.

Then, in step 3 during the unwinding operation of each stage, in the process of inserting the fork 4 between the pallets P ₁ and P ₂ of the first stage and the second stage, the fork 4 is
The touch sensor 8 installed at the tip of the pallet
If the need for inter-search operation is detected by contacting P ₁ and P ₂ , the process proceeds to step 10.

When proceeding to step 10, the supply of working fluid to the forward side of the drive cylinder 5 is immediately stopped, and the bogie 2
suddenly stops, working fluid is supplied to the backward drive side of the drive cylinder 5 to drive the truck 2 backward, and when the truck 2 moves backward to the backward limit, the supply of working fluid to the drive cylinder 5 is stopped and the step is stopped.
Go to 11.

In step 11, it is checked whether or not the touch sensor 8 comes into contact with the pallets P ₁ and P ₂ for the first time after the start of stack unwinding. If it is the first contact, the process proceeds to step 12.

When the process proceeds to step 12, the first interval search operation is started, and the drive motor 6 operates for a certain period of time to raise the fork 4 to the trial operating point _H1 , after which the process returns to step 2.

Returning to step 2, the truck 2 is driven forward by the drive cylinder 5, so that the fork 4 located at the trial operating point _H1 moves to the lowest pallet.
P ₁ (or pallet P ₂ ) and the pallet P ₂ above it
(or palette P ₃ ).

Then, in step 3, the fork 4 is inserted without interfering with the pallets P ₁ , P ₂ (or pallets P ₂ , P ₃ ) during the insertion process into the gap, and the fork 4 is inserted into the carriage 2.
When it reaches its forward limit, the supply of working fluid to the drive cylinder 5 is stopped and the process proceeds to step 4, after which steps are removed in the order of steps 4 to 9.

In addition, in step 3 of the first interval search, when the touch sensor 8 again detects interference between the fork 4 and the pallets P ₁ and P ₂ (or pallets P ₂ and P ₃ ) during the insertion process of the fork 4, The process proceeds to step 10, in which the trolley 2 is brought to a sudden stop and then moved backward, and the process proceeds to step 11.

In step 11, it is checked whether or not the touch sensor 8 comes into contact with the pallets P ₁ and P ₂ (or pallets P ₂ and P ₃ ) for the first time after the start of step unwinding, and if it is not the first contact, the step continues. Proceed to 13.

When the process advances to step 13, it is checked whether or not the touch sensor 8 has been contacted for the second time after the start of step unrolling, and if it is the second time, the process proceeds to step 14.
Proceed to.

When the process proceeds to step 14, a second interval search operation is started, and the drive motor 6 is operated for a certain period of time to lower the fork 4 to the trial operating point _H2 , after which the process returns to step 2.

Returning to step 2, the truck 2 is driven forward, so that the fork 4 located at the trial operating point H ₂ moves again to the lower pallet P ₁ (or pallet
P ₂ ) and the pallet above it P ₂ (or pallet P ₃ )
If _the fork ₄ is inserted toward the gap _{between the} Step removal is performed in the order of each process up to the stapling step 9.

In addition, in step 3 of the second interval search, when the touch sensor 8 again detects interference between the fork 4 and the pallets P ₁ and P ₂ (or pallets P ₂ and P ₃ ) during the insertion process of the fork 4, Then, proceed to step 10. In step 10, the trolley 2 is brought to a sudden stop and then moved backward, and the process proceeds to step 11.

In step 11, it is checked whether or not the contact of the touch sensor 8 is the first time after the start of step breaking. If it is not the first contact, the process proceeds to step 13. Check whether it is the second contact after the start, and if it is not the second contact, proceed to step 15.
Proceed to.

When proceeding to step 15, the first and second inter-interval search operations do not search between the inter _- intervals, making it impossible to insert fork _{4 .} After it is determined that there is a problem and the cart 2 is moved backward, the fork 4 is returned to the reference point H ₀ and the tier removing device 1 is returned to the standby state, and an alarm is issued to notify the operator of the occurrence of an abnormality in the tier opening operation. Emitted.

Furthermore, in step 6, when the presence or absence of pallet P ₁ (or pallet P ₂ ) below fork 4 is checked, it is determined that pallet P ₁ (or pallet P ₂ ) remains below fork 4 without being conveyed. If so, return to step 5, and in step 5 operate conveyor 9 to remove the lowest pallet.
After conveying pallet P ₁ (or pallet P ₂ ) to the product loading section, the process proceeds to step 6, where the presence or absence of pallet pallet P ₁ (or pallet P ₂ ) below the fork 4 is checked again to confirm that it has been conveyed. Then, the process advances to step 7, and thereafter each process of step 8 and step 9 is performed in order.

In addition, in the case of this embodiment, the pallets P ₁ , P ₂ , and P ₃ that were brought in in a three-tier stacked state are
I explained the case where the steps are taken apart step by step.
The present invention can be similarly applied to the case of unpacking pallets stacked in four or more stages, and can also be applied to an apparatus for unpacking stacked pallets every predetermined number of stages of two or more stages.

In addition, in the control program installed in the control device of the step separating device 1 of this embodiment, as a search operation performed by changing the height of the fork 4, a trial is made to set the height of the fork 4 higher than the reference point _H0 . Operating point
_{The production equipment} If there is sufficient cycle time for other equipment as a whole, by increasing the number of trial operating points, it is possible to deal with pallet height errors more widely.

Effects of the invention As explained above, the automatic stacking pallet unloading device of this invention has a fork that is driven forward and backward and raised and lowered by the drive mechanism, and the tip of the fork is moved forward at a reference height and brought into contact with the pallet. The fork is provided with a touch sensor that detects the positional deviation when the positional deviation occurs, and when the touch sensor detects the positional deviation, the fork is moved back to the operating origin,
and a control device for controlling the drive mechanism to raise or lower the pallet by a predetermined amount and move it forward again; and means for carrying out the pallet remaining below the lifted pallet;
Even if the pallets are contaminated with oil or the like or oil or the like adheres to the sensor section, it is possible to reliably detect the deviation in the height direction of the fork with respect to the gap between the pallets and prevent malfunctions. In addition, if a deviation in the height direction of the forks is detected, the
It is possible to automatically move the fork to a height where it can be inserted by searching for the space between the steps, allowing for step-breaking operation.
This eliminates the need to sort out pallets with large height errors when the pallets are brought in, resulting in a significant reduction in work time and the ability to significantly reduce line stoppage time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a stacking device and stacked pallets, and FIG. 2 is a flowchart of a control program. DESCRIPTION OF SYMBOLS 1... Tier unbending device, 2... Dolly, 3... Mast, 4... Fork, 5... Drive cylinder, 6...
...Drive motor, 7...Chain, 8...Touch sensor, 9...Conveyor, P, _P1 , _P2 , _P3 ...Pallet.

Claims (1)

[Scope of utility model registration request] A fork, which can be driven forward and backward and up and down by a drive mechanism, is advanced from the operating origin, inserted between the stacked pallets, and raised, leaving pallets up to a predetermined number of stages, and then lifting the pallets up to a predetermined number of stages. In an automatic unwinding device for stacked pallets, which lifts pallets stacked on the pallet and unwinds the pallets sequentially from the lower stage, a fork is installed at the tip of the fork to prevent positional shift when the fork is advanced at a reference height and comes into contact with the pallet. The fork is provided with a touch sensor to detect the positional deviation, and when the touch sensor detects the positional deviation, the fork is moved back to the operating origin, raised or lowered by a predetermined amount, and then moved forward again. A control device is provided for controlling the drive mechanism until the pallet is inserted or repeatedly for a predetermined number of times, and further includes a control device for carrying out the pallet remaining below the pallet lifted by the fork from below the pallet lifted by the fork. 1. An automatic stacking pallet unpacking device characterized by comprising means for stacking pallets.