JPH0436983B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an article palletizing system using an industrial robot.

Conventional technology: A wide variety of products are stacked on separate pallets for each product type, and a desired number of desired products are picked up from each pallet, and the various products are mixed onto a specific empty pallet. There is palletizing work that involves loading and unloading.

Then, by automating this kind of work, we can accurately pick up items from individual pallets and unload them onto empty pallets, and ensure that the loaded pallets are stacked in an orderly manner. It is advantageous to use industrial robots for positioning, especially when the shape of the article is a special shape such as a bucket that fits into each other at the top and bottom so that it can be stacked in multiple tiers. This cannot be achieved without the use of industrial robots, as this requires the use of industrial robots.

However, if the above-mentioned palletizing work is carried out using, for example, an ordinary cylindrical coordinate robot 1 while moving the robot 1 in a traverse direction as shown in FIG. The depalletizing operation (depalletizing operation) and the stacking operation (palletizing operation) on empty pallets 4 for final stacking are performed accurately, and the articles 3 are piled up in an orderly manner without collapsing. The number of items that can be transported is limited to two or three at most, and the robot itself must traverse each time it picks up two or three items to transport them to an empty pallet. Therefore, the disadvantage is that the processing efficiency per hour is extremely low.

Problems to be Solved by the Invention This invention solves the problem of low processing efficiency per hour when industrial robots are used for palletizing work as described above, and also improves the processing efficiency of pallets for final stacking. This also speeds up the loading and unloading of the pallets after stacking the articles, thereby increasing the efficiency of the entire palletizing work.

Means for Solving the Problems This invention provides an industrial robot in which a loading cart for final stacking pallets is connected to a moving section of a hand section for grasping, picking up and unloading articles, and The present invention proposes a system in which a conveyor for loading and unloading pallets and a temporary storage stand for articles are provided on a cart, and the conveyor is driven by a rotary drive source installed according to the position of loading and unloading the pallets.

Embodiment First, a palletizing system for plastic cases containing appropriate articles (bottled beverages, etc.) will be described based on FIGS. 1 to 4.

As shown in the plan view in FIG. 1, the palletizing system of this example has a substantially rectangular parallelepiped plastic case 5 containing articles in eight locations A,
An appropriate number of each of B, C, D, E, F, G, and H are depalletized from the large pallet 6 by the orthogonal coordinate robot 7, and variously placed onto the small pallet 9 for final stacking on the mobile cart 8, which will be described later. It is a system that mixes and stacks the mixture, and there are 8 locations A, B ~
The products in each plastic case 5 of H are of different types, and the orthogonal coordinate robot 7 of this example
The operator grasps, lifts and transfers the cases 5 from the large pallet 6 at each position to the small pallet 9 by the number instructed by a higher-level control device (not shown).

Reference numeral 11 denotes a cart for loading and unloading the large pallets 6 that runs parallel to the eight large pallet 6 storage areas. Position A,
Transfer of B to H to the large pallet storage area is carried out by a roller conveyor 12 on the cart 11. A large number of free balls 13 are provided on the upper surface of each large pallet storage area (FIG. 2).

A slat conveyor 14 is provided at one end of the large pallet 6 storage area and serves as a loading/unloading station for the small pallets 9. The small pallets 9 are loaded/unloaded onto the slat conveyor 14 by a forklift or the like. Reference numerals 15 and 16 are rails of the movable cart 8 and the cart 11, respectively.

Hereinafter, the orthogonal coordinate robot 7 and the mobile cart 8 will be explained in detail.

That is, the gate-shaped X-axis frame 17 of the orthogonal coordinate robot 7 in this example is made long so that the movable Y-axis frame 18 can move over a long process to match the storage location of the large pallet 6. Rollers 2 are attached to the upper and lower rails 21 and 22 on the shaft frame 17.
A movable frame 27 that supports hands 25 and 26, which will be described later, is movably provided on the Y-axis frame 18, which is rotatably supported via 3 and 24.

28 is a moving rail on the Y-axis frame 18 of the moving frame 27.

The moving frame 27 has two lifting arms 3.
1 and 32, and the lifting arm 3
A hand 25 for gripping and lifting the plastic case 5 and a hand 26 for suctioning and lifting the cardboard box are attached to the lower ends of 1 and 32, respectively, so that even if the items to be handled are changed, the hands 25 and 26 can be used easily. It can be used selectively to palletize articles of either type. That is, in this example, the X-axis frame 17, the movable Y-axis frame 18, the moving frame 27, and the elevating arms 31, 32 also constitute the moving parts of the hands 25, 26.

The hand 26 is a normal robot hand that has a vacuum pad 33 and can pick up three boxes at a time, but the case gripping hand 25 has the following structure.

In other words, the plastic cases 5 on each large pallet 6 are placed on the pallet 6 at a predetermined position and orientation, but the positional accuracy is rough (approximately ±20 mm in both the X and Y axes directions). The hand 25 must pick up the loaded cases 5 with this rough positioning accuracy and stack them at a predetermined accurate position on the small pallet 9 after the movement, and the bottom and top surfaces of the cases 5 must be They are formed into shapes 5a that fit into each other (Fig. 3),
The cases 5 on each pallet 6, 9 must be loaded with the upper case 5 fitted into the lower case 5. In order to satisfy this requirement, the hand 25 has the following characteristics. It has a similar structure.

That is, as shown in the third and fourth figures, the hand 2
Reference numeral 5 has a so-called double hand, which includes movable frames 37 and 38 that support a pair of grip claws 35 and 36 that are driven to open and close by a cylinder 34, and a movable frame 37 and 38 that supports the grip claws 35 and 38 themselves. 36
It consists of a support frame 39 that is slidably supported in a direction orthogonal to the opening/closing direction, and the lifting arm 31 is connected to the support frame 39.

Guide rods 37a and 38a constitute a part of each moving frame 37 and 38, 39a a guide rod constitute a part of the support frame 39, and a stopper part 41 is provided at the intermediate part of the guide rods 37a and 38a.
The stopper portion 41 restricts the moving end (closing width) of the grip claws 35, 36 when they are closed by the cylinder 34, and also allows the grip claws 35, 36 to open to grip the case 5. When the grip claws 35, 36 and the case 5 are moved to the right in FIG. The rightward position in FIG. 3 is regulated.

In other words, if the left-right direction in Figure 3 is the X-axis direction,
The case 5 gripped by the grip claws 35 and 36 is positioned relative to the hand 25 in the X-axis direction by the contact of the base end of the grip claw 35 with the stopper portion 41 by the retracting action of the cylinder 42. It is.

Reference numeral 43 designates a mounting bracket for the positioning cylinder 42 which is fixedly protruding from each of the movable frames 37, 38.

A compression spring 44 is interposed between the movable frame 38 and the support frame 39, and a cylinder 45 that expands and contracts in the left-right direction (Y-axis direction) in FIG. 4 is connected between the movable frame 37 and the support frame 39. When the cylinder 45 is contracted, the case 5 is in the state shown in the fourth figure.
The grip claws 35, 36 and the movable frames 37, 38 are moved to the right in FIG. It is adapted to be positioned by coming into contact with the bracket 46.

Reference numerals 47 and 48 are flange-shaped stopper portions provided on the guide rod 39a, respectively.
4 left direction position (Y-axis direction position) of each moving frame 37, 38 when 5 and spring 44 are extended
to regulate.

Note that the outer edge of the hand 25 in plan view is smaller than the outer edge of two cases 5 arranged side by side, and other cases 5 are stacked high around the desired case 5 to be gripped. Even when the case 5 is present, the hand 25 can descend and approach the desired position directly above the case 5 to be gripped.

Note that the positioning of the case 5 gripped by the grip claws 35 and 36 in the X-axis direction with respect to the hand 25 may be performed by an extension operation of the positioning cylinder 42.

Next, the movable trolley 8 will be explained. The movable trolley 8 is connected to the X-axis direction rail 2 of the robot 7.
1 and 22, and one half of its upper surface is connected to a slat conveyor 49 for placing small pallets 9.
The other half is configured as a case 5 or a temporary storage stand 51 for items such as boxes. In this embodiment, since the small pallet 9 is a pallet without a lower plate, a slat conveyor 49 is used, but other conveyors such as a belt or a chain may of course be used.

The movable cart 8 does not have a drive device in this embodiment, and has a recess formed in the side surface.
Only after the movable Y-axis frame 18 of the robot is fitted with a connecting pin 52 that can move forward and backward is fitted.
The carriage 8 is moved along the rail 15 along with the axis frame 18, and when the connecting pin 52 retracts toward the Y-axis frame 18 and the fitting is disengaged, the trolley 8 is moved along the rail 15. It continues to stop at the position where it was removed.

Further, an input shaft of the slat conveyor 49 protrudes from the side of the cart 8 as a clutch piece 53.
At the position where the truck 8 is connected to the Y-axis frame 18 as described above and moved to the rightmost end in the X-axis direction (dotted chain line in FIG. 1), the input shaft clutch piece 53 is mounted on the floor. It engages with the clutch piece 54 serving as a rotational output shaft, and in this state, the carriage 8 is first rotated.
The upper slat conveyor 49 is designed to rotate.

55 is a wheel, and 56 is a cylinder for advancing and retreating from the connecting pin 5.

The placement positions of the cases 5 on the temporary storage table 51 are divided into 8 parts, as shown by the chain line in FIG. 1, just like the placement positions on the small pallet 9. Case 5 of 4 types (for example, large pallet 6 at positions A, B, C, and D)
The upper case) is prioritized and temporarily placed in the predetermined placement sections 51a, 51b, 51c, and 51d on the temporary storage stand 51, and the remaining cases 5 (for example, E, F, G, The case on the large pallet 6 at position H is temporarily placed on a fixed temporary storage table 57 provided at the leftmost end of the large pallet 6 storage area in FIG.

Furthermore, the mounting position of the case 5 on the fixed temporary mounting table 57 is also divided into eight parts as shown by the chain line in FIG.
The presence or absence of cases for each type on the temporary storage stand 51 and fixed temporary storage stand 57 is determined by the micro switch and photoelectric switch installed on the respective stands 51 and 57. etc. (not shown).

Next, the operation of the above palletizing system will be explained.

In other words, before operating the system,
Using the loading and unloading trolley 11, each position A, B ~
A large pallet 6 loaded with a large amount of cases 5 of each type is carried and placed in a large pallet storage area H.

At this time, if the objects are transported from the right side to the left side in FIG. 1 in order of frequency of handling in the system, the moving distance of the Y-axis frame 18, that is, the robot hands 25 and 26 can be shortened.

The types in the case 5 on the large pallet 6 at each position carried in as described above are shown below at each position A,
According to B to H, A variety, B variety...H variety.

Further, the small pallet 9 is also carried onto the slat conveyor 49 of the movable cart 8 using the slat conveyor 14.

That is, the movable trolley 8 connected to the Y-axis frame 18 is moved to the position indicated by the chain line in FIG. The slat conveyor 14 serving as a carry-in/out station is driven at the same time, and the empty small pallet 9 on the slat conveyor 14 is carried onto the cart 8 (dashed line in FIG. 1).

After preparing the above initial state, the orthogonal coordinate robot 7 is operated according to the program by the upper control device. A command for coupling and uncoupling with the trolley 8 (that is,
The movement of the moving cart 8 is performed in complete synchronization with the palletizing operation of the case 5 by the robot 7.

That is, for example, when loading 15 cases of type A, 8 cases of type B, and 9 cases of type C onto the small pallet 9, first move the Y-axis frame 18 to the A position with the mobile cart 8 connected. move,
At this position, once the connection is removed and the movable trolley 8 is stopped, the Y-axis frame 18 and the lifting arm 3 are removed.
1 and the hand 25 are operated to pick up the 14 cases 5 from the large pallet 6 at position A and transfer them onto the small pallet 9 (of course, this is done in 7 batches of 2 cases each).

Once the loading of the 14 cases of type A has been completed, the Y-axis frame 18 and the movable trolley 8 are reconnected, the movable trolley 8 is brought to the B position, and the connection is disconnected again, and the movable trolley 8 is moved again. This time, stop at position B. Then, the Y-axis frame 18, the lifting arm 31, and the hand 25 are operated in the same manner as above.
Eight cases 5 are transferred from the top of the large pallet 6 to the small pallet 9.

Furthermore, in the same manner, the moving cart 8 is brought to the C position, and eight cases 5 are transferred from the large pallet 6 at the C position onto the small pallet 9.

With the above operation, most of the loading cases other than the fraction of the number of loading cases for each product type are completed, but then the fraction (in other words, in the case of robot hand 25 in this example, it is a double hand, so the fraction is always 1)
The processing is performed as follows.

In other words, after the loading of the number of cases other than the fraction of the above C type is completed, also at the C position,
Grasp two cases 5 with hand 25,
One of the grabbed cases 5 is placed on the predetermined placement section 51c of the temporary storage table 51, and the remaining grabbed cases 5 are stacked on top of the cases 5 on the small pallet 9 that has already been stacked. Yes, then connect the Y-axis frame 18 and the movable trolley 8
hand 2 in the same way at that position.
5, pick up two cases 5, place one of the grabbed cases 5 on a predetermined placement section 51a of the temporary storage table 51, and place the remaining cases 5 still grabbed on the small pallet 9. The rounding process is completed by adding up the numbers.

With the above operations, 15 cases of type A, 8 cases of type B, and 9 cases of type C are loaded onto the small pallet 9 as planned, and one case each of type A and C are temporarily placed on the temporary storage table 51. However, in this state, the top of the small pallet 9 is full, so the movable cart 8 is moved to the slat conveyor 14 position at the right end in FIG.
3 and 54 are engaged with each other to drive the slat conveyor 14 and carry out the full small pallet 9.

Note that the hand 25 is responsible for picking up the case 5 (depallet operation) and placing it on the small pallet 9 (palletizing operation).
Since the structure has the positioning function as described above, even if the case position on the large pallet 6 is in a rough positioning state, it can be picked up well, and moreover, the case can be picked up in a predetermined manner onto the small pallet 9. The fitting part 5 on the bottom of the case 5 is placed in the correct position.
The fitting of part a is also performed well (described in detail later).

Then, move the next small pallet 9 to the cart 8.
Next, 15 cases of type A, 9 cases of type B, and 8 cases of type C were delivered to the small pallet 9.
If loading is to be carried out upwards, most of the loading other than the fractional number is performed by the same operation as above, but the loading operation of the fractional number uses the case 5 remaining on the temporary storage table 51 from the previous palletizing operation. This is done as follows.

In other words, according to the same procedure as before, 14 cases of type A, 8 cases of type B, and 8 cases of type C are loaded before rounding, and after this operation is completed, one case each of type A and type B are loaded. To do so, first move and stop the moving cart 8 at position B, pick up two cases 5 of B type with the hand 25, and place one of the cases 5 on the B position on the temporary storage stand 51. The case 5 of the type A is placed on the placement section 51b for the type, and the case 5 of the type A on the temporary storage stand 51 is lifted up using the vacant grip claws 35 and 36, while the case 5 of the other type B is held. Then, while holding 51 cases of different types, A type and B type, in the hand 25 at the same time, they are transferred onto the small pallet 9 and placed all at once.

Therefore, one case 5 of type B and one case 5 of type C remain on the temporary storage stand 51, and the cases 5 of type B and type C will also be used in the subsequent palletizing work.

In addition, each mounting section 51a, 51 on the temporary mounting table 51
The presence or absence of cases b, 51c, and 51d is detected by a micro switch or the like as described above, but since each mounting section 51a, 51b, 51c, and 51d has an area equivalent to 52 cases, that is,
Since there is a free space for at least one case on the side of the placed case 5, for example, as in the above-mentioned rounding operation, one of the grip claws 35, 36
While holding the case 5, another case 5 on the temporary stand 51 can be grabbed and operated. The same applies to the fixed temporary storage stand 57.

In addition, in the above operation example, the case 5 was depalletized only from the large pallets 6 at positions A, B, and C, but the same applies when depalletizing from the large pallets 6 at other positions.
When performing a depallet operation for rounding off large pallets 6 at positions F, G, and H, use the fixed temporary storage table 57 to place each type of product E, F, G, and H on the temporary storage table 57. The case 5 is temporarily stored, but when there are few types of large pallets 6, that is, when there are few types, there is no need to provide the above-mentioned fixed temporary storage table 57, and the large pallets 6 (product types) are )
Even when there are many types of products, by increasing the area of the temporary storage table 51 on the movable trolley 8, all types from the large pallet 6 can be temporarily placed on the movable trolley 8.

Next, the operation of picking up the case 5 by the hand 25 (depallet operation) and the operation of placing it on the small pallet 9 (palletizing operation) will be explained.

That is, as mentioned above, each plastic case 5 is stacked on the large pallet 6 with a positioning accuracy of about ±20 mm, and the top and bottom surfaces of the plastic cases 5 are fitted into each other, so that the plastic cases 5 are
5 first closes the grip claws 35, 36, and lowers each movable frame 37, 38 while contacting the left end in FIG. 34, the grip claws 35, 36 are opened at low pressure and engaged with the handle hole 5b of the case 5.

When the grip claws 35, 36 are engaged with the case 5, the movement of the grip claws 35, 36 in the horizontal plane (movement in both the X and Y axes directions) is controlled by guide rods 37a, 38a, and 39a, respectively. Since the positioning cylinders 42 and 45 are freely held (at this point, the positioning cylinders 42 and 45 are freely retracted), even if the position of the case 5 deviates from the normal position, the grip claws 35 can be adjusted to match the position of the case 5. ,36
is opened, and no unreasonable force is applied to the case 5, and even if the case 5 is fitted with the lower case 5, it can be picked up without any problem (in this example,
Since the handle hole 5b is wide in the Y-axis direction, there is no problem in the Y-axis direction).

Then, when the hand 25 is raised and the case 5 is lifted with the grip claws 35 and 36 open and engaged under low pressure as described above, the curved portions at the tips of the grip claws 35 and 36 are bent by the weight of the case. At this point, the supply pressure to the cylinder 34 is switched to high pressure, and the positioning cylinders 42 and 45 are contracted to move the case 5 to the X, as described above. Position in the Y-axis direction.

Case 5 that was picked up as described above
The hand 25 is positioned with respect to the hand 25, and by this positioning, the loading onto the next small pallet 9 or onto the temporary storage tables 51, 57 is performed accurately according to the set position, and the upper and lower cases 5 are not stacked against each other. They fit together smoothly and are stacked up.

Furthermore, although the above explanation of the operation was for palletizing the plastic case 5 by the hand 25, when the hand 26 is used to palletize a large number of cardboard boxes stacked on each large pallet 6 onto the small pallet 9. The same operation is also performed efficiently using the temporary storage tables 51 and 57.

In the above system example, an orthogonal coordinate type robot is used as the industrial robot, and the moving trolley 8 for loading small pallets is connected to the movable Y-axis frame 18 as the moving part of the hands 25 and 26. Sometimes the hands 25 and 26 can only move in two directions, the Y and Z axes, relative to the small pallet 9.
Therefore, when transferring the case 5, it was necessary to disconnect the trolley 8 and the Y-axis frame 18.
For example, by using a cylindrical coordinate robot having a traverse device instead of the orthogonal coordinate robot 7, the following system that does not require the above-mentioned disconnection operation can be constructed.

That is, as shown in FIG. 5, along the traverse path 63 of the cylindrical coordinate type robot 62 mounted on a cart-type traverse device 61, a storage area for the large pallet 6 and a movement path 65 for the mobile cart 64 are constructed. A conveyor 66 for carrying in and out of small pallets and a temporary storage table 67 are provided on the moving trolley 64, and the connection between the moving trolley 64 and the traverse device 61 as a moving part of the robot in this example is as follows. As in the previous example, this is accomplished by fitting the pin 68, which is moved back and forth by a cylinder as appropriate, into a recessed hole on the side of the traverse device 61. 7
A conveyor 3 serves as a loading/unloading station for the small pallets 9.

The depalletizing operation of the articles 5 from the large pallet 6 and the palletizing operation onto the small pallet 9 by the robot 62 are performed in substantially the same order as in the above example, except that the above-mentioned cart 64 and the traverse device 61
Since the hand (double hand) 69 of this robot 62 is capable of three-dimensional movement even when the robot 62 is connected, the article 5 can be transferred without disconnecting.

Reference numerals 71 and 72 are an input shaft to the cart-mounted conveyor 66 and an output shaft provided on the floor, respectively, similar to the above-described example.

Effects of the Invention As is clear from the above explanation, the robot system according to the present invention is capable of performing the above-mentioned palletizing work with high processing efficiency using an industrial robot, and moreover, it is possible to perform the above-mentioned palletizing work with high processing efficiency, and moreover, it is possible to perform the palletizing work as described above with high processing efficiency. Since the loading and unloading of pallets can be carried out quickly using the conveyor mounted on the cart itself, the entire palletizing work including loading and unloading of pallets can be made highly efficient. Since the conveyor on the truck is driven by a drive source installed at the pallet loading/unloading position, there is no need to provide all drive sources on the truck, resulting in a simple structure. Furthermore, when the cart reaches the carry-in/export position, the conveyor drive can be started immediately, which further improves work efficiency and allows the stop position of the cart to be regulated. Further, by providing a temporary storage stand, it is possible to efficiently perform the loading process of fractional quantities in particular.

[Brief explanation of drawings]

Figures 1 to 4 are examples of palletizing systems using orthogonal coordinate robots, with Figure 1 being an overall plan view, Figure 2 being a sectional view taken along the line - - in Figure 1, and Figure 3 being a side view of the robot hand. , Figure 4 is a front view of the same,
FIG. 5 is a plan view of a palletizing system using a cylindrical coordinate robot, and FIG. 6 is a schematic diagram showing a conventional palletizing method. 5...Plastic case (article), 6...Large pallet, 7...Cartesian coordinate robot, 8...Moving trolley (loading trolley), 9...Small pallet (final stacking pallet), 17...X axis frame, 18
...Movable Y-axis frame, 25, 26... Robot hand, 27... Moving frame, 31, 32... Lifting arm, 49... Slat conveyor.

Claims (1)

[Claims] 1. In a robot having a hand section for grasping, picking up and unloading articles, and a moving section for moving the hand section, the moving section is equipped with a conveyor for carrying in and out of pallets and a temporary storage table for articles. A robot system for palletizing goods, characterized in that a loading cart for final stacking pallets is connected, and a conveyor on the cart is driven by a rotary drive source installed according to the pallet loading/unloading position.