JPH0217445B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an industrial robot, and in particular, it extracts a desired number of desired types from a plurality of pallets piled up for each type of goods, and small-sizes them. Related to robots that palletize on pallets.

[Conventional technology]

When robots are used to transport goods, they often move box- or case-shaped goods from a predetermined stack of pallets to another pallet, and then stack them again in a predetermined shape on the pallet. In other words, it is a process of palletizing, but if this process is performed by a robot, it will certainly pick up a specified item from a group of items stacked on one pallet (depallet work) and pick up a specified item from a group of items piled up on one pallet, and the other. The stacking work (palletizing work) on the pallets is carried out accurately,
Although the articles are piled up in an orderly manner, the number of articles that can be conveyed in one conveyance operation is at most 2 to 3, and since depalletizing and palletizing operations take time, the processing efficiency per hour is lower than that of belts. The cost is not as high as when using a conveyor and having workers load and unload before and after the conveyor.

In addition, in order to increase the number of items that can be handled in one depalletizing or palletizing operation, efforts are being made to make the robot's hand into a so-called double hand (a hand with two gripping functions) or more capable of gripping a large number of items. However, in that case, only the hand section would be too large and heavy, which would be unfeasible in terms of cost and structure, or it would be a hindrance that depalletizing and palletizing operations could not be carried out smoothly. It may be extremely difficult to properly grip a large number of objects placed in a rough position at the same time, or the casing of the hand itself may interfere with objects other than the target object on the pallet, causing the hand to reach the target object. Serious problems may occur, such as the inability to access the area.

[Problem that the invention seeks to solve]

Therefore, this invention solves the problem of low processing efficiency per hour when robots are used for conveyance work as described above, and also solves the problem of low processing efficiency per hour when robots are used for conveyance work. This allows work to be carried out smoothly.

[Means for solving problems]

In this invention, a moving part of a hand part is provided with a mounting table for an article that moves along with the hand part, and when picking up an article (during a department store), the article picked up by the hand is placed on the mounting table. A positioning mechanism on the mounting table positions the article with high accuracy, and the mechanism of the hand itself can be simplified.

〔Example〕

First, based on FIGS. 1 to 5, the first
An example of this will be described with respect to an orthogonal coordinate robot used in a conveyance and palletizing system for plastic cases containing bottles.

In this conveyance and palletizing system, a roughly rectangular parallelepiped plastic case 2 containing a large number of bottled beverages 1 is depalletized by a robot hand from large pallets 3 at three locations (A), (B), and (C), and then transported to one location. This is a system in which the beverages are stacked on the small pallet 5 at D, and the bottled beverages 1 in each plastic case 2 stacked on the large pallet 3 at three locations (A), (B), and (C) are of different types. , Robot R
transports the cases 2 from the large pallet 3 at each position to the small pallet 5 in the number instructed by a higher-level control device (not shown).

Therefore, the moving part Ra of the orthogonal coordinate robot R in this example is designed to have a particularly long moving distance in the X-axis direction (Figs. 1 and 2) along the pallets 3 and 5. The hand portion Rb moved by the portion Ra is particularly structured to be suitable for picking up the plastic case 2.

The moving part Ra and hand part Rb of this robot will be explained in detail below.

That is, the moving part Ra includes a gate-shaped frame 7 having a long rail part 6 along the X-axis direction,
It consists of a Y-axis frame 8 extending in the Y-axis direction that moves on the rail section 6, and a vertical arm 9 that moves on the Y-axis frame 8 along the Y-axis, and the vertical arm 9 is configured as described above. A robot hand 10 is attached to the lower end of the vertical arm 9, which is movable in parallel along the Y-axis and can be raised and lowered up and down.

In this example, another vertical arm 11 having the same function, that is, movable along the Y-axis and the Z-axis, is provided parallel to the vertical arm 9.
Another hand 13 having a vacuum pad 12 is attached to the lower end of the hand 13, so that this hand 13 can also carry and palletize articles that can be carried by suction, such as cardboard boxes. I don't mention it. Therefore, the hands 10 and 13 constitute a hand section Rb. The hand 10 is rotatable around a vertical axis via a rotary actuator 14 at the lower end of the vertical arm 9, and as described above, this hand 10 has a structure suitable for grasping and lifting the plastic case 2. ing.

In other words, the plastic cases 2 on each large pallet 3 are loaded on the pallet 3 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 10 must pick up the loaded cases 2 with rough positioning accuracy and stack them at a predetermined and accurate position on the small pallet 5 after the movement, and the bottom and top surfaces of the cases 2 must be aligned with each other. It has a shape that fits into it (Figures 3 and 4).
The cases 2 on each pallet 3, 5 must be loaded with the upper case 2 fitted to the lower case 2, and the hand 10 has the following structure that satisfies the above requirements. There is.

That is, as shown in the third and fourth figures, the hand 1
Reference numeral 0 denotes movable frames 18 and 1 which have a so-called double hand structure and slidably support a pair of grip claws 16 and 17 which are driven to open and close by a cylinder 15.
9, and a support frame 21 that supports the movable frames 18, 19 so as to be slidable in a direction perpendicular to the sliding direction of the grip claws 16, 17.
9 and 21, and a vertical arm 9 is connected to the support frame 21 via the actuator 14.

22 is a guide rod for the grip claws 16 and 17 installed on each moving frame 18 and 19; 23 is a support frame 2;
1, and the guide rod 22 has a grip claw 1.
Stopper portions 24 and 25 are provided between the gripper claws 6 and 17 and on one side of the grip claw 17, respectively.
The moving end (closing width) when the grippers 6 and 17 are closed is regulated, and depending on the stopper part 25, the grip claw 1
6 and 17 are open and gripping case 2 (4th
When the grip claws 16, 17 and the case 2 are moved together by the cylinder 26 to the right in FIG. 4, the right end is regulated. The position toward the right in FIG. 4 is restricted.

In other words, if the left-right direction in Figure 4 is the Y-axis direction,
The case 2 gripped by the grip claws 16 and 17 is positioned relative to the hand 10 in the Y-axis direction by the grip claw 17 coming into contact with the stopper portion 25 due to the retracting action of the cylinder 26. .

Furthermore, in the closed state in which the grip claws 16 and 17 are regulated by the stopper portion 24,
When the hand 10 descends, even if the case 2 is displaced in the Y direction (however, the displacement is limited to within about 20 mm), the lower ends of the grip claws 16 and 17 should not come into contact with the bottle 1 inside the case 2. It's getting old. 20mm
If there is any deviation in the Y direction, either of the grip claws 16, 17 will come into contact with the upper edge of the case and the robot will come to an emergency stop. Reference numeral 27 denotes a detection bar protruding horizontally from the lower ends of the grip claws 16 and 17. When the hand 10 descends, the case 2 is severely displaced in the X direction in FIGS. 3 and 4 (approx. 20 mm or more), the detection bar 27 comes into contact with the upper edge of the case 2 to prevent the hand 10 from moving downward, and also to emergency stop the operation of the robot.

Then, each of the moving frames 18 and 19 and the support frame 21
Connected between them are cylinders 28 and 29 that extend and contract in the left-right direction (X-axis direction) in FIG. , moving frame 18,1
The case 9 is moved to the right in FIG. The case 2 shown above is the case 2 on the right side of Figure 3 that was positioned first
It is designed to be positioned by coming into contact with it.

Reference numerals 31 and 32 denote stopper portions provided on the guide rod 23, respectively, which restrict the positions of the movable frames 18 and 19 in the left direction (X-axis direction) in FIG. 3 when the cylinders 28 and 29 are extended. 33 is moving frame 18
This is a connecting bracket for connecting the cylinder 28 protruding from the cylinder 28.

Note that the upper left end of the moving frames 18 and 19 in FIG. 4 and the upper left end of the support frame 21 in FIG. Even if there is another case 2 loaded on the side of the desired case 2 (dotted line in FIGS. 3 and 4), the hand 10 will be able to grasp the desired case 2. The case 2 can be lowered to a position directly above the case 2 to be gripped.

In this embodiment, the above hand 1
A mounting table 35 for the case 2 is fixed via a vertical plate 34 to the Y-axis frame 8 to which the Y-axis frame 8 is attached via a vertical arm 9.

The mounting table 35 has two hands 10 in this embodiment.
Since it can hold several cases 2, it has an upper area equivalent to two cases, and a total of four cases 2 can be placed on top of it in two rows and two stages (Figure 2). ,
The size, shape, etc. of the mounting table 35 can be varied depending on the size and type of the article to be handled, the number of articles that can be held at one time by the hand, etc.

Further, as shown in the plan view shown in FIG. 5, the mounting table 35
Pushers 36 and 37 extending upward in the X and Y axis directions and a positioning surface 3 facing the pushers 36 and 37
8 and 39, the case 2 can be positioned by movement by the pushers 36 and 37, and the positioning accuracy of the case 2 on the mounting table 35 can be improved. If the positioning accuracy of the robot hand 10 can be performed with high precision, it becomes possible to make the positioning accuracy of the robot hand 10 rougher to some extent when gripping an object, and the structure of the robot hand 10 can be simplified accordingly, and the positioning accuracy on the robot hand 10 can be made simpler. The positioning work of the case 2 can be omitted and the time required for the process can be shortened. In addition, in FIG. 5, 35a is a U-shaped rising wall, and 35b is a T-shaped raised portion forming the positioning surfaces 38, 39.

Next, the conveyance and palletizing process by the conveyance robot of the first embodiment will be explained.

That is, the robot receives commands from the upper control device and moves the Y-axis frame 8 to predetermined positions (A), (B), and (C).
The case 2 is moved to the large pallet 3 at the position, and the commanded number of cases 2 are depalletized from the pallet 3 at the relevant position, and after being conveyed, they are stacked on the small pallet 5. At this time, the mounting table 35 is moved along the Y axis. Since it is fixed to the frame 8 and is always near the hand 10, and moves along with the movement of the hand 10, the transport process is as follows.

That is, as mentioned above, each plastic case 2 is stacked on the large pallet 3 with a positioning accuracy of about ±20 mm, and the top and bottom surfaces of the plastic cases 2 are fitted into each other.
0 closes the grip claws 16 and 17, and each moving frame 1
8 and 19 descend while in contact with the stopper portions 31 and 32, respectively (FIG. 3), and the grip claws 16 and 17
First, insert the tip into the space between the upper edge of the case 2 and the bottle inside the case, supply low-pressure oil to the cylinder 15, open the grip claws 16 and 17 under low pressure, and open the handle hole of the case 2. 2a. When the grip claws 16, 17 are engaged with the case 2, the grip claws 16, 17 move in the horizontal plane (X, Y
axial movement) is carried out by guide rods 22, 2, respectively.
3 (at this point, the cylinders 26, 28, and 29 can freely expand and contract), so even if the position of case 2 deviates from the normal position, it will be adjusted to the position of case 2. The grip claws 16 and 17 open, and the case 2 is not subjected to excessive force, and even if the case 2 is fitted with the lower case 2, the grip claws 16 and 17 are opened. Since the hole 2a is wide, there is no problem in the X-axis direction). In addition, if the positional deviation of the case 2 is severe, such as ±20 mm or more, the tips of the grip claws 16 and 17 or the detection bar 27 may
As described above, the hand 10 comes into contact with the upper edge of the hand 10 to prevent the hand 10 from descending, thereby stopping the operation urgently.

Then, when the hand 10 is raised (raises the vertical arm 9) and the case 2 is picked up with the grip claws 16 and 17 open and engaged under low pressure, the case's own weight causes the grip to open. Claw 1
The bent portions at the tips of 6 and 17 are securely engaged with the upper surface of the handle hole 2a, and at this point the cylinder 1
5 is switched to high pressure, the cylinders 26, 28 and 29 are contracted, and the case 2 is positioned in the X and Y axis directions as described above. During this positioning in the X-axis direction, the grip claws 16 and 17 move relatively within the handle hole 2a, but the width of the handle hole 2a is sufficiently wider than the grip claws 16 and 17. , and since the upper surface of the hole 2a is a smooth horizontal surface, the case 2
The movement and positioning of the support frame cm by bringing it into contact with the lower end 21a of the support frame cm is performed smoothly.

The case 2 picked up as described above is positioned with respect to the hand 10, and once positioned, it is lowered onto the mounting table 35.

That is, when there are three or more cases 2 to be transported, the first two cases picked up as described above are unloaded onto the mounting table 35, and then the number of cases 2 to be transported is adjusted accordingly. , new 1
Processes such as making the hand 10 grip one case 2, or picking up two cases 2 from the same pallet 3 and stacking them on the case 2 on the mounting table 35 are performed. In other words, the third or more cases 2 that cannot be held by the hand 10 are placed on the mounting table 3.
5 and place it on top.

Even when the cases 2 are stacked and placed on the mounting table 35, since the cases 2 have already been positioned relative to the hand 10, the upper and lower cases 2 can be quickly and easily stacked in a fitted state.

After the above depallet work is completed, the Y-axis frame 8 is moved to position the hand 10 on the small pallet 5, but as the Y-axis frame 8 is moved, the mounting table 35 is also moved at the same time. The small pallet 5 is palletized by the robot hand 10 in the following manner.

That is, first, one or two cases 2 held in the hand 10 are unloaded onto a predetermined position on the small pallet 5, and then, after picking up the case 2 loaded on the mounting table 35, It is loaded and unloaded at a predetermined position on the pallet 5, and at this time, not only the case 2 held in the hand 10 but also the case 2 on the mounting table 35 are loaded in an accurately positioned state, so that The process from picking up from above 35 to loading and unloading on small pallet 5 can be performed quickly and smoothly without requiring new positioning.

(A), (B), and (C) Depallet work from one of the large pallets 3 and palletizing work onto the small pallets 5 are performed as described above, and thereafter, other types of cases 2 are carried out in the same manner. It is conveyed from above the other large pallet 3 and palletized to the small pallet 5.

The small pallet 5, on which a predetermined number of cases 2 of different types are stacked as described above, is pushed by a pusher 42 provided on the front of a lifter 41 which also serves as a mounting table for the small pallet 5, and is placed in a waiting position at the rear. It is transferred to a transport fork 43, which is located there, and thereafter transported to the next step by the fork 43.

In addition, as with the above-mentioned conveyance and palletizing system, various articles can be transported to different locations (pallets).
When it is necessary to separate different numbers of articles from each other, the mounting table 35 can be used as a temporary storage area for the articles in the following manner to further improve processing efficiency.

That is, in the above embodiment, if the number of articles to be transported from each position (A), (B), and (C) to position (D) is an odd number, first ) Transport (predetermined number - 1) pieces (an even number) from the pallets at each position, and then depallet one piece from the pallets at each position (A), (B), and (C). However, at that time, using the mounting table 35, move the Y-axis frame 8 sequentially from the top of the pallet at position (A) at one end to position (C),
As well as carrying out the depalletizing work one by one, the depalletized cases 2 are temporarily placed on the mounting table 35, and when they reach position (D), they are temporarily placed on the placing table 35. It is sufficient to palletize the various cases 2 placed on the small pallet 5 at once, and when the mounting table 35 is not used, the Y-axis frame 8 can be moved between each position (A) to (D), (B). The time required is significantly reduced compared to the case in which it is necessary to move back and forth between ~(D) and (C) and (D) each time.

Also, for example, when transporting a certain type of case, the number of cases to be transported will be taken into consideration when transporting the specific case 2 next time, and a fraction (for example, 1 to 3) will occur in the number of cases to be transported next time. In this case, if the fractional number of cases is placed on the mounting table 35 when the specific case 2 is first transported, the specific type remaining on the mounting table 35 during the second transport process can be All you have to do is immediately stack the cases 2 on the target pallet, compared to the case where the Y-axis frame 8 is newly moved to the pallet position where the specific type of cases 2 are loaded and a fraction of the cases 2 are newly depalletized. This will significantly reduce the time required.

Note that in the first embodiment, the hand 10 has two pairs of grip claws 16 and 17 and is of a so-called double-hand type that grips two cases 2 at a time. The hand may be of any type (of course it may have other holding mechanisms such as vacuum time), and the number of objects that can be held at one time by the hand itself is not limited to two. The shape of the mounting table 35,
The size is also not limited to the above.

In addition, in the above embodiment, the mounting table 35 is vertically disposed from the Y-axis frame 8 so that relatively light weight articles can be placed thereon, but the weight and quantity of articles to be conveyed at once is If the carrier is large or the conveyance path is long, it is possible to provide a track for the mounting table 35, which will be described next as a second embodiment.

That is, as shown in FIG. 6, the orthogonal coordinate robot of the second embodiment has almost the same configuration as the first embodiment, and has a gate-shaped frame 45 extending long along the X-axis direction. , a hand movement part Ra consisting of a Y-axis frame 47 that runs on the rail 46 of the gate-shaped frame 45, and vertical arms 48 and 49 that can be raised and lowered and that move on the Y-axis frame 47 along the Y-axis. , and the vertical arms 48, 49
It consists of a hand part Rb attached to the lower end.

The hand portion Rb includes a vacuum type hand 51 and two pairs of grip claws 52 attached to the lower ends of two vertical arms 48 and 49, respectively, as in the first embodiment.
The hand 53 has a grip claw type hand 53, and can pick up and unload cases 2 on pallets 54 and 55 in the same manner as described above.

In this example, the base end side of the Y-axis frame 47 extends downward, and a mounting table 56 is connected to the lower end portion 47a. It is supported on rails 58 extending in the X-axis direction and laid on the base of the mold frame 45.

61 and 62 are a pallet placing table 63 and a pallet placing table 5, respectively.
These are free-rotating balls that allow the pallets 54 and 55 to move smoothly on the pallets 6.

Since the mounting table 56 of the second embodiment is configured as described above, the case 2 which has been detached from the large pallet 54 by the hand 53 is placed on the mounting table 5.
Even if a large number of items are loaded on the rail 5, the mounting table 56
8, the vertical plate 3 supporting the mounting table 35 as in the first embodiment described above
There is a risk that the mounting table 5 may be easily damaged due to an excessive bending moment applied to the mounting table 56, and there is no need to make the vertical plate 34 from a material with extremely high strength. Case 2
can be loaded, and the movement in the X-axis direction is extremely smooth.

In addition, the above-mentioned mounting table 56 and the lower end portion 4 of the Y-axis frame
The connection point with 7a is connected by a locking device 64, which has a structure in which an engaging pin appears and retracts, and can be released from the connected state, and when carrying out the conveyance work without using the mounting table 56, the locking device 64 is connected. 64 can be released and the Y-axis frame 47 can be used as a conventional type of moving means without the mounting table 56, or the robot can be used to carry out conveyance and palletizing operations similar to those described in the first embodiment above. In the case where the mounting table 56 and the Y-axis frame 47 are
It can also be used by fixing or releasing the connection between them. The unfixed mounting table 56 is stopped at a fixed point on the X-axis regardless of the movement of the Y-axis frame 47, but it can of course be used as a mounting table for articles (cases) even in this state. When using the mounting table 56 again as a mounting table 56 that moves along with the hand Rb, the Y-axis frame 47 is moved to the position of the mounting table 56 that is stopped at a fixed point on the rail 58, and then The locking device 6
Just input 4 and connect.

The first and second embodiments described above both relate to orthogonal coordinate type robots, but next, embodiments relating to other types of robots will be described.

That is, as shown in FIG. 7, this is a robot system in which a cylindrical coordinate type robot main body Rc is mounted on a traverse cart 65, and a mounting table 66 for the article P is provided on the traverse cart 65. In this case, the moving part Ra of the robot hand Rb
consists of a traverse truck 65, a vertical guide post 67 of the robot body Rc, and a swing arm 68 that moves up and down along the guide post 67 and moves back and forth in the horizontal direction.

Therefore, the mounting table 66 can also be provided on a moving part Ra other than on the traverse cart 65.

It goes without saying that the robot body Rc on the traverse cart 65 may be another type of robot such as a multi-joint type or a polar coordinate type.

〔Effect of the invention〕

As is clear from the above description, in the article conveying robot of the present invention, the hand and the mounting table are attached to the Y-axis frame that moves in the horizontal direction, that is, between the articles stacked by type and the small pallets. Therefore, the palletizing process, in which a desired number of desired products are taken out and stacked, can be carried out with extremely high efficiency.

In other words, the total number of objects held by the hand and those placed on the mounting table are transported to the small pallet side by one horizontal movement of the Y-axis frame. This reduces the number of reciprocating movements and increases work efficiency. Furthermore, since two or more articles can be placed on the mounting table, a large number of articles can be conveyed, and a wide variety of articles can be conveyed to the small pallet at the same time.

In addition, since a small number of articles can be preliminarily stored on the mounting table, when picking up and palletizing various articles in different numbers as in the first embodiment, the target palletizing If the number of items to be loaded and unloaded at a location is sufficient with the preloaded items on the loading table, the preloaded items may be immediately unloaded at the target location, and the hand section is moved onto the large pallet of the item of the type. There is no need to carry out a new departmental operation, and depending on the type of conveyance system used, the loading table can be used as a temporary storage area for the articles, so that the efficiency of conveying the articles can be improved.

Furthermore, since the pushers and positioning surfaces on the mounting table allow for highly accurate positioning of the object on the mounting table, it is possible to make the positioning accuracy of the robot hand rougher to some extent when gripping the object. Since the structure can be simplified, the hand can be manufactured at low cost, and the work of positioning the article on the robot hand can be omitted, reducing the time required for the process.

In addition, in the robot of the present invention, when the pair of grip claws grips an article on a large pallet, the article gripping hand has a compliance mechanism (that is, a compliance mechanism in which the pair of grip claws performs the gripping operation while following the position of the article). Both grip claws are movable along the guide rod, and a mechanism is provided in which a cylinder for opening and closing is installed directly between both grip claws, so that they fit together without being movable in the horizontal direction and are held high. Even if the stacked items are not accurately positioned and may shift slightly, it is possible to remove the items one by one without fear of disrupting the stacked condition. You can lift it up and store it separately.

Furthermore, the article lifted by the compliance mechanism is not held in a predetermined position with respect to the gripping hand as it is;
Although the position held by the robot has not been specified,
When the article is transferred onto the mounting table and the pusher on the mounting table is operated, the position where the article is held by the robot is accurately specified, so that the article can be lifted from the mounting table again with the gripping hand and placed in a small position. When transferring items onto a pallet, the items can be lifted and unloaded accurately without the compliance mechanism being activated, and the loading posture of the items on the small pallet can be maintained in an orderly manner, and the compliance mechanism does not need to be activated. You can save minutes.

[Brief explanation of drawings]

1 to 5 show the first embodiment, FIG. 1 is an overall front view, FIG. 2 is a side view, FIG. 3 is a front view of the hand section, and FIG. 4 is a vertical cross-sectional side view of the hand section. 5 is a plan view of the mounting table, FIG. 6 is a side view of the second embodiment, and FIG. 7 is a schematic diagram of the third embodiment. 2...Case, 3...Palette, 5...Small Palette,
6...Rail, 7...Gate frame, 8...Y-axis frame, 9...Vertical arm, 10...Robot hand, 1
1... Vertical arm, 13... Robot hand, 35...
Placement table, 36, 37... Pusher, 38, 39... Positioning surface, Ra... Moving part, Rb... Hand part.

Claims (1)

[Claims] 1 Items stacked by type on a plurality of large pallets, and the upper and lower items are fitted horizontally so as not to be movable, and small pallets in which a desired number of desired types of items are taken out and loaded. A Y-axis frame that moves horizontally along rails disposed on the side, and a vertical arm that is disposed on the Y-axis frame and is movable in parallel along the Y-axis frame and can be raised and lowered in the vertical direction. , an article gripping hand attached to the lower end of the vertical arm, and a mounting table fixed to the Y-axis frame via a vertical plate on which a plurality of articles can be placed, the article gripping hand comprising:
When the pair of grip claws grips an article on the large pallet, it has a compliance mechanism that moves to grip the article while following the position of the article. A robot for transporting articles, characterized in that it is provided with a pusher that accurately positions the robot in both vertical and horizontal directions on a horizontal plane, and a positioning surface that faces the pusher.