JP2022127104A - Hand and method for pickup of container by use of the hand - Google Patents

Abstract

To provide a hand which can hold an object with a peripheral wall whose upper side is opened.SOLUTION: A hand comprises: a plurality of three or more fingers 14 which are discretely arranged in a circumferential direction; an actuator 16 which is connected to the plurality of fingers, performs spreading out movement of the plurality of fingers so as to be radially outward away from each other, and performs return movement thereof so as to approach each other radially inward; and a guide member 18 which is provided at a prescribed relative height position with respect to the plurality of fingers, and butts against an upper end 2b of a peripheral wall of an object 2 to be held, thereby regulating a relative height relation between the object and the plurality of fingers. Each of the plurality of fingers 14 has a friction body 30, which applies a static frictional force to an inner surface 2a of the peripheral wall of the object to be held, on at least a face on a radial outward side.SELECTED DRAWING: Figure 1

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand that holds an object having, for example, a peripheral wall whose upper side is open using static frictional force against the inner surface of the peripheral wall.

2. Description of the Related Art Conventionally, in supermarkets, convenience stores, and the like, an object having a peripheral wall with an upper opening, such as a soup container, placed in an object to be placed, such as a lunch box, has been sold. Such a dipping sauce container is, for example, a container for dipping dipping sauce for dipping noodles.

For example, in the process of manufacturing lunch boxes, such objects such as soup containers are taken out one by one from a plurality of stacks of objects in which a plurality of objects are stacked on top of each other. placed one inside.

However, when an object such as a soup container is to be arranged one by one in each object to be arranged, conventionally, it is necessary for an operator to arrange the object, which is laborious and costly for the operator. I had a problem.

Therefore, the inventors of the present invention have conducted intensive research on a hand for placing objects such as soup containers one by one in each placement object. The inventors of the present invention have studied, for example, picking up an object by using a hand equipped with a suction cup. However, when trying to pick up objects such as soup containers one by one from a state in which a plurality of them are stacked, there is a gap between the first object to be taken out and the second object adjacent to the first object. Another problem is that a negative pressure is generated and the second object is ejected together with the first object.

Further, the inventors of the present invention have studied, for example, taking out the object by grasping the outer circumference of the object with a hand. However, in a state in which a plurality of the objects are stacked, a large number of the objects are stacked in the height direction, so the action of a small amount of force causes the object at the upper end to tilt, or the position and height to slightly change. I had something to do. Therefore, it is difficult to grasp and take out the objects one by one from a state in which a plurality of the objects are stacked, and there is a problem that the hand fails to pick up the objects or drops them.

The present invention was invented in view of the above background. SUMMARY OF THE INVENTION It is an object of the present invention to provide a hand capable of holding an object having a peripheral wall with an open upper side.

In order to achieve the above object, one embodiment of the present invention provides a hand that holds an object having a peripheral wall with an upper opening using static friction against the inner surface of the peripheral wall,
three or more fingers discretely arranged in the circumferential direction, connected to the plurality of fingers, and expanding and moving the plurality of fingers radially outward away from each other; an actuator configured to move back toward each other radially inward; and a guide member that defines a relative height relationship between the object and the plurality of fingers by abutting against, each of the plurality of fingers having at least a radially outer surface thereof: It has a friction body that applies a static friction force to the inner surface of the peripheral wall of the object to be held.
In one embodiment of the present invention configured as described above, the guide member can define the relative height relationship between the object and the plurality of fingers, and the friction body is provided on the inner surface of the peripheral wall of the object. Actuating positions can be relatively stably defined, and the actuator spreads and moves the plurality of fingers radially outward away from each other, so that the friction bodies of each of the plurality of fingers are held. A static frictional force can be applied to the inner surface of the peripheral wall of the target object to hold the object having the peripheral wall with the upper side open. In addition, according to the configuration of the present embodiment, for example, from a state in which a plurality of objects having peripheral walls with an upper side open are stacked, for example, objects having peripheral walls with an upper side open are picked up one by one. can be held.

In one embodiment of the present invention, preferably, the friction body is a cylindrical member formed of a viscoelastic material so as to cover the entire peripheral surface of each finger.
In one embodiment of the present invention configured as described above, the friction body is a tubular member formed of a viscoelastic material and formed so as to cover the entire peripheral surface of each finger. When the position at which the friction body acts on the object to be held changes due to a slight movement of the object to be held, or when the position at which the friction body acts on the object to be held changes due to changes in the shape or size of the object to be held In this case, the friction bodies of each of the plurality of fingers can easily apply a static frictional force to the inner surface of the peripheral wall of the object to be held, and the object having the peripheral wall with the upper side open can be held more reliably. . In addition, the friction body can easily hold the object in response to, for example, a difference in shape due to a manufacturing error of the object and a difference in shape such as variations in the shape of the object.

In one embodiment of the present invention, the guide member preferably has a plurality of abutment elements that abut against the upper end of the peripheral wall of the object to be held at a plurality of points.
In one embodiment of the present invention configured as described above, the guide member has a plurality of contact elements that contact the upper end of the peripheral wall of the object to be held at a plurality of points. The element adjusts the relative height relationship between the object and the fingers at a plurality of locations, and the guide member can more stably define the relative height relationship between the object and the plurality of fingers. , the contact position of the friction body with the peripheral wall of the object can be more stably defined.

In one embodiment of the present invention, preferably each of the plurality of abutment elements is arranged at a position not overlapping each of the plurality of fingers when viewed in the radial direction.
In one embodiment of the present invention configured as described above, each of the plurality of abutting elements is arranged at a position not overlapping with each of the plurality of fingers when viewed in the radial direction. and friction bodies attached to the fingers are less likely to interfere, and the guide member stably regulates the relative height relationship between the object and the plurality of fingers, while each of the plurality of fingers has The friction body exerts a static frictional force on the inner surface of the peripheral wall of the object to be held, so that the object having the peripheral wall whose upper side is open can be held more reliably.

In one embodiment of the present invention, preferably, the plurality of fingers are circumferentially equally spaced so as to have rotational symmetry, and the actuator moves the plurality of fingers between the plurality of fingers. is configured to be moved in the radial direction while maintaining the rotational symmetry of
In one embodiment of the present invention configured in this way, the actuator is configured to radially move the plurality of fingers while maintaining rotational symmetry of the plurality of fingers. As a result, the friction body of each of the plurality of fingers is moved in the radial direction while maintaining rotational symmetry, and the static friction force is generated at a position having rotational symmetry with respect to the inner surface of, for example, the annular peripheral wall of the body. to make it easier to hold an object in a well-balanced manner, and to make it easier to hold an object having, for example, an annular peripheral wall.

In one embodiment of the present invention, preferably, from a state in which a plurality of flexible containers having a peripheral wall with an upper side opened are stacked, the containers are picked up one by one using static frictional force against the inner surface of the peripheral wall. a plurality of fingers of three or more discretely arranged in a circumferential direction; and a plurality of fingers connected to the plurality of fingers to spread and move the plurality of fingers radially outward away from each other. and an actuator configured to move radially inwardly toward each other, and an actuator provided at a predetermined relative height position with respect to the plurality of fingers, the peripheral wall of the container to be held. a guide member that impinges on the upper end to define a relative height relationship between the container and the plurality of fingers, each of the plurality of fingers extending at least on the radially outer side surface a hand having a friction body that applies a static frictional force to the inner surface of the peripheral wall of the container to be held; bringing the guide member closer to the container and abutting the guide member against the upper end of the peripheral wall of the container; The container is expanded outward away from each other, contacts the inner surface of the peripheral wall, and deforms the peripheral wall in the radial direction, and the peripheral wall of the container and the container stacked below the container due to the deformation. forming a gap between the container and the peripheral wall of the container; and a step of picking up the container separated from the container stacked under the container.
In one embodiment of the present invention configured as described above, the step of creating a gap causes the plurality of fingers to move radially outward while the guide member abuts against the upper end of the peripheral wall. and move away from each other to contact the inner surface of the peripheral wall and further deform the peripheral wall in the radial direction, and by the deformation, the peripheral wall of the container and the container stacked below the container In the step of creating a gap between the container and the peripheral wall and picking up the container, the plurality of fingers deform the peripheral wall of the container in the radial direction, and the hand is retracted upward to lift the container. It is separated from the container stacked below the container and picked up. As a result, from a state in which a plurality of flexible containers having peripheral walls that are open at the top are stacked, the containers can be picked up one by one using the static frictional force on the inner surface of the peripheral wall.

ADVANTAGE OF THE INVENTION According to this invention, the hand which can hold|maintain the object which has the surrounding wall which the upper side opened can be provided.

1 is a front view of a holding system provided with a hand according to a first embodiment of the invention; FIG. 2 is a top view of the hand of FIG. 1; FIG. When the hand shown in FIG. 1 is lowered onto a plurality of stacked objects and the guide member of the hand hits the upper end of the object, the fingers are closed and the friction body is positioned inside the object. It is a perspective view showing a state where When the hand shown in FIG. 1 is lowered onto a plurality of stacked objects and the guide member of the hand hits the upper end of the object, the fingers are closed and the friction body is positioned inside the object. FIG. 3 is a cross-sectional view of a state in which the state is viewed along the IV-IV line in FIG. 2; 5 is a top view showing a state in which the fingers of the hand shown in FIG. 4 are changed from the closed state to the open state, and the friction body supports the object from the inside; FIG. FIG. 5 is a cross-sectional view taken along line IV-IV in FIG. 2 showing a state in which the fingers of the hand in FIG. 4 change from the closed state to the open state and the friction body supports the object from the inside; FIG. 5 is a top view of a hand according to a second embodiment of the invention; FIG. 8 is a side view of the two-divided arm portion of the guide member of the hand of FIG. 7 as seen from the lateral side; FIG. 8 is a front view of the two-divided arm portion of the guide member of the hand of FIG. 7 as seen from the front side;

A hand according to a first embodiment of the present invention will be described with reference to the accompanying drawings.
First, a hand according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view of a holding system provided with a hand according to a first embodiment of the present invention; FIG. 2 is a top view of the hand of FIG. 1; FIG. In FIG. 2, the fingers of the hand are closed.

A hand 1 of this embodiment holds an object 2 to be held. A hand 1 of this embodiment is provided in a holding system 4 that holds an object 2 . The object 2 is an object having a peripheral wall 2a whose upper side is open, for example, a container having a peripheral wall 2a whose upper side is open, for example, a dipping sauce container for dipping noodles. The holding system 4 holds the object 2, moves the object 2 while holding it, and positions the object 2 at a target position. A holding system 4 is provided along the conveyor belt 8 . A holding system 4 places the object 2 on a placement object 10 which is conveyed on a conveyor belt 8 .

The object 2 includes not only a soup container but also a relatively small container that opens upward, such as a cup container, a small container, a tray, a plate, and a case. The object 2 is made of a material such as resin or paper. The object 2 is, for example, a container made of resin such as polyethylene (PE) or polypropylene (PP). It has as much rigidity as possible.

The object 2 is formed in the shape of a circular vessel when viewed from above, the upper end of the peripheral wall 2a forms a circular edge when viewed from above, and the lower end (outer periphery of the bottom) of the peripheral wall 2a is formed circularly. there is Note that the object 2 may be formed in the shape of a quadrilateral container, an elliptical container, or a pleated container in which the peripheral wall is pleated even though it is generally circular, when viewed from above. The object 2 is formed in the shape of a container with a bottom, and its depth can be changed. The object 2 is not limited to a container capable of containing a liquid, such as a frame-shaped body formed without a bottom or a bottom-opening member having a hole formed in the bottom, but is a structure other than a container having a peripheral wall whose upper side is open. good too. In addition, the objects 2 are arranged in a standby position on the side of the conveyor belt 8 in a state in which a plurality of objects 2 are stacked. The plurality of stacked objects 2 are arranged inside three support rods 9 for preventing the stacked plurality of objects from falling.

The holding system 4 has a robot arm 12 that can freely adjust the position and height of the arm, and the hand 1 is attached to the robot arm 12 . Therefore, the horizontal position and vertical position of the hand 1 can be freely changed by the robot arm 12 . The hand 1 may include a robot arm 12 and have a function of adjusting its own position.

The conveyor belt 8 conveys the placement object 10 in the direction indicated by the arrow A with the placement object 10 placed thereon. The arrangement target object 10 is an object on which the object 2 is arranged, and is, for example, a boxed lunch container containing ingredients of a boxed lunch. The placement object 10 is not limited to a boxed lunch container, and includes a food container, a container in which the object 2 can be placed, a tray, a plate, a case, etc., as long as it is an object on which the object 2 is placed.

Next, the hand will be described in more detail with reference to FIGS. 1 to 6. FIG.
FIG. 3 shows that when the hand of FIG. 1 is lowered onto a plurality of stacked objects and the guide member of the hand hits the upper end of the object, the fingers are in a closed state and the friction body is positioned inside the object. FIG. 4 is a perspective view showing a state in which the hand of FIG. 1 is positioned at a position; FIG. 5 is a cross-sectional view taken along line IV-IV of FIG. 2 in the closed state with the friction body positioned inside the object, and FIG. 5 is the finger of the hand of FIG. FIG. 6 is a top view showing a state in which the fingers of the hand in FIG. FIG. 3 is a cross-sectional view taken along line IV-IV of FIG. 2;
The hand 1 holds the object 2 using static frictional force against the inner surface of the peripheral wall 2a. A hand 1 picks up and holds objects 2 one by one from a state in which a plurality of objects 2 are stacked, and conveys the objects 2 to a specific position on a placement target 10 on a conveyor belt 8 .

The hand 1 has a plurality of fingers 14 of three or more arranged discretely in the circumferential direction, an actuator 16 connected to the plurality of fingers 14, and a predetermined relative height to the plurality of fingers 14. A guide member 18 provided at a position and abutting against the upper end of the peripheral wall 2a of the object 2 to be held to define the relative height relationship between the object 2 and the plurality of fingers 14, and the actuator 16. and a control device 20 for controlling.

Fingers 14 extend radially outward from the sides of actuator 16 . The finger 14 has a mounting portion 14 a extending downward from the lower portion of the outer side, and the mounting portion 14 a is mounted inside the friction body 30 . The plurality of fingers 14 are arranged at equal intervals in the circumferential direction so as to have rotational symmetry. Fingers 14 are configured to be driven by actuators 16 , and fingers 14 are configured to be slidable radially outwardly and radially inwardly relative to actuators 16 . Actuator 16 is thus configured to radially move fingers 14 while maintaining rotational symmetry of fingers 14 . More specifically, the fingers 14 are positioned between a closed state in which the outer ends of the fingers 14 are positioned relatively close to the actuator 16 and an open state in which the outer ends of the fingers 14 are positioned outside the closed position. is slid with For example, the number of fingers 14 can be changed to 4, 5, 6, or the like. In the closed state of the fingers 14, the friction body 30 is not sufficiently pressed against the inner wall of the object 2, while in the open state of the fingers 14, the friction body 30 is sufficiently pressed against the inner wall of the object 2. , so that the object 2 can be supported with the friction body 30 stretching from the inside.

The actuator 16 is movable to advance the plurality of fingers 14 outwardly from the actuator 16 and retract back inwardly of the actuator 16 in a horizontal direction. The actuator 16 is configured to move the plurality of fingers 14 radially outwardly to spread apart and away from each other and to move them back radially inwardly toward each other.

Actuator 16 is configured as a pneumatic finger that pneumatically moves finger 14 between the closed and open positions. Actuator 16 is formed by a so-called double-acting actuator having two pressure chambers, a first pressure chamber (not shown) and a second pressure chamber (not shown). The actuator 16 opens the finger 14 when the air pressure acting inside the first pressure chamber is higher than the air pressure acting inside the second pressure chamber, and the air pressure acting inside the first pressure chamber is higher than the air pressure acting inside the first pressure chamber. The fingers 14 are designed to be closed when a high air pressure acts inside the second pressure chamber. A pneumatic line 22 is connected to each of the first pressure chamber and the second pressure chamber of the actuator 16 . The other end of air pipe 22 is connected to compressor 24 . Compressor 24 is configured to compress air for delivery toward each of the first pressure chamber and the second pressure chamber. The actuator 16 may be formed by a so-called single-acting actuator having one pressure chamber. However, the actuator 16 may be configured as a mechanical finger that changes the position of the finger 14 between the closed state and the open state by a mechanical power transmission structure such as a motor and a power transmission mechanism.

The guide member 18 extends substantially horizontally radially outward from the side of the actuator 16, and then has an arm portion 26 hanging downward from the outer end of the horizontal portion. It has a plurality of abutment elements 28 which are provided and which abut against the upper edge 2b of the peripheral wall 2a of the object 2 to be held at a plurality of points. The guide member 18 has a function of stabilizing the posture of the object 2 to be picked up, and also has a function of positioning the friction body 30 at a position where it overlaps the upper end of the object 2 as will be described later. The guide member 18 may also have the function of guiding and stabilizing the posture and relative positional relationship of the actuator 16 and the finger 14 with respect to the object 2 . Further, the guide member 18 can correct the inclination and floating of the second and subsequent objects 2 from the top of the stacked objects 2 so that the stacked objects 2 extend vertically.

Each of the plurality of arm portions 26 and each of the plurality of contact elements 28 are arranged at positions not overlapping with each of the plurality of fingers 14 when viewed in the radial direction. Further, each of the plurality of arm portions 26 and each of the plurality of contact elements 28 are provided between each of the fingers 14 in the circumferential direction when viewed from above. The arm portions 26 and the abutment elements 28 are circumferentially equally spaced and arranged with rotational symmetry.

The abutment elements 28 are arranged at three equally spaced locations in the circumferential direction. This allows the abutment element 28 to contact the upper end 2b in the vicinity of a rotationally symmetrical position, making the position, orientation and/or tilt of the object 2 stable and easier to adjust. The abutting element 28 is formed in a narrow plate shape and extends in an arc along the arc of the upper end 2 b of the object 2 . Since the lower surface of the contacting element 28 is flat and plate-like, the contacting of the contacting element 28 with the upper end 2b stabilizes the position, orientation and/or inclination of the object 2 and facilitates adjustment. The lower surface of the contact element 28 is formed in a narrow plate shape, but may be formed by a circular contact surface or the like.

As shown in FIG. 1, controller 20 is electrically connected to actuator 16 and robot arm 12 . The control device 20 incorporates a CPU, memory, etc. for controlling the actuator 16 and the robot arm 12 . The control device 20 sends operation signals to these devices and the like based on a control program executed on the CPU to control each device and the like.

The control device 20 brings the hand 1 closer to the object 2 to be held from above and abuts the guide member 18 against the upper end of the peripheral wall 2a of the object 2; With the guide member 18 abutting against the end thereof, the plurality of fingers 14 are moved radially outward to expand away from each other and come into contact with the inner surface of the peripheral wall 2a, further pushing the peripheral wall 2a. a step of radially deforming the object 2 to create a gap between the peripheral wall 2a of the object 2 and the peripheral wall 2a of the object 2 stacked below the object 2; a step of picking up the object 2 while separating the object 2 from the object 2 stacked below the object 2 by retracting the hand 1 upward while the peripheral wall 2a of the object 2 is being deformed in the radial direction; It is equipped with a program that can execute each step of The control device 20 also has a program necessary for executing the operation of the hand 1 .

Next, the friction body will be described with reference to FIGS. 1 to 6. FIG.
As shown in FIG. 1, the hand 1 is attached to a structure such as a robot arm 12 or the like. Each of the plurality of fingers 14 has a friction body 30 that exerts a static frictional force against the inner surface of the peripheral wall 2a of the object 2 to be held, at least on its radially outer surface. The friction body 30 is a cylindrical member formed of a viscoelastic material so as to cover the entire peripheral surface of the mounting portion 14a of each finger 14. As shown in FIG. The friction body 30 is a resin tubular member made of a resin-based viscoelastic material.

The friction body 30 is formed of a cylindrical silicon ball. The spherical surface of the side portion of the silicon ball comes into contact with the inner surface of the peripheral wall 2a and exerts a relatively large static frictional force. The friction body 30 is formed in a hollow shape, has a flexible surface portion, and can be crushed inward. The friction body 30 is not limited to a cylindrical shape, and may be a spherical shape, an outward pad shape, an outward plate shape, or the like. As shown in FIG. 5, when the fingers 14 are in the closed state, the guide member 18 is in contact with the object 2, and the radially outer surface of the friction body 30 is positioned inside the peripheral wall 2a of the object 2. positioned. An imaginary arc B indicated by an imaginary line passing through the radially outer surfaces of the three friction bodies 30 is located inside the contact element 28 in top view. When the fingers 14 are in the open state, the radially outer surface of the friction body 30 is in contact with the peripheral wall 2 a of the object 2 . In addition, the peripheral wall 2a in contact with the radially outer side surfaces of the three friction bodies 30 is positioned below the contact element 28 when viewed from above. When the number of friction bodies 30 is three or four, the central position of the object 2 can be corrected to some extent when the plurality of friction bodies 30 spread. Also, when the number of friction bodies 30 is three or four, the distance between the parts where the friction bodies 30 do not contact the object 2 when the plurality of friction bodies 30 spread is relatively large. The deformation of the second object 2 makes it relatively easy to form a gap with the second object 2 . The friction body 30 may be a rubber tubular member made of, for example, a rubber-based viscoelastic material. Furthermore, the friction body 30 may be a cylindrical member made of other viscoelastic material.

The top of the friction body 30 is located above the abutment element 28 of the guide member 18 and the bottom of the friction body 30 is located below the abutment element 28 of the guide member 18 . Therefore, when the guide member 18 abuts against the upper end 2b, the friction body 30 is positioned at a position where it touches the upper end of the object 2 (a position where the upper end 2b is between the upper end and the lower end of the friction body 30 in a side view). . The friction body 30 is positioned and sized so that when the guide member 18 abuts against the upper end 2b, the friction body 30 extends from the upper end 2b of the object 2 to near the center of the height of the peripheral wall 2a in a side view.

Next, the operation (action) of the hand according to the above-described embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG.
As shown in FIG. 1, an arrangement object 10, which is, for example, a boxed lunch container, is placed inside the arrangement object 10 after ingredients such as noodles are served in the arrangement object 10 in an upstream serving process (not shown). ) are conveyed by the conveyor belt 8 to the working area of the hand 1 of the holding system 4 . The control device 20 acquires and recognizes the positional information of the placement object 10 from an image or the like taken by a camera or the like (not shown).

The control device 20 picks up the objects 2 one by one from a state in which a plurality of objects 2, for example, a flexible container having a peripheral wall whose upper side is open, is stacked. Move over object 2. The control device 20 lowers the hand 1 vertically downward with respect to the object 2, brings the hand 1 closer to the object 2 from above the object 2 to be held, and moves the upper end 2b of the peripheral wall 2a of the object 2. Then, a step of abutting the guide member 18 is executed. At this time, the finger 14 is closed and the friction body 30 is also closed. The control device 20 performs control to lower the hand 1 to the height of the object 2 at a predetermined height position. On the other hand, the object 2 is supplied to a predetermined height position by an object supply device (not shown) for the object 2 . The object supply device uses, for example, a transmissive sensor (transmissive sensor) or the like to supply the object 2 to a predetermined height position. Therefore, the hand 1 lowered to a predetermined height can stably hit the object 2 at a predetermined height position.

Therefore, as shown in FIGS. 3 and 4, the guide member 18 abuts against the upper end 2b of the peripheral wall 2a of the object 2, the lowering of the hand 1 is stopped, and the plurality of objects 2 are stacked. At least the inclination and positional deviation of the first and second objects 2 from the top are corrected. Then, with the guide member 18 in contact with the upper end 2b of the peripheral wall 2a of the object 2, the friction body 30 is inserted to a predetermined height from the upper end 2b of the peripheral wall 2a. At this time, the friction body 30 is separated from the peripheral wall 2a. Although any one of the friction bodies 30 may be in contact with the peripheral wall 2a, at least one friction body 30 is separated from the peripheral wall 2a to the extent that the friction body 30 can lift the object 2. The object 2 is not held. The guide member 18 allows the friction body 30 to be stably inserted at a predetermined height in the object 2 each time, and to be held relatively stably.

The control device 20 performs a step of expanding and moving the plurality of fingers 14 radially outward away from each other while the guide member 18 is abutted against the upper end 2b of the peripheral wall 2a. For example, the plurality of fingers 14 are spread and moved so that the virtual arc along the outer surface of the plurality of friction bodies 30 has a larger diameter than the peripheral wall 2 a of the object 2 . Then, as shown in FIGS. 5 and 6, the friction body 30 is brought into contact with the inner surface of the peripheral wall 2a. The three friction bodies 30 contact the inner surface of the peripheral wall 2a, so that the object 2 is held by the friction bodies 30 from the inside. More specifically, the spread movement of the plurality of fingers 14 presses the friction body 30 against the inner surface of the peripheral wall 2a, and static friction between the friction body 30 and the object 2 is generated against the pressing force of the friction body 30. A force is generated, and since this static friction force is larger than the self weight of the object 2, the object 2 is supported in the air without falling. Also, in this state, the object 2 can be supported by the friction body 30 stretching from the inside.

As a result, the plurality of friction bodies 30 act from the inside to the outside so as to expand the peripheral wall 2a in the radial direction, and the friction bodies 30 deform the peripheral wall 2a in the radial direction centering on the portion where the friction bodies 30 act on the peripheral wall 2a. A step of forming a gap between the peripheral wall 2a of the container-shaped object 2 and the peripheral wall 2a of the container-shaped object 2 stacked below the container-shaped object 2 is executed by . In this way, a gap is formed between the peripheral wall 2a of the uppermost container-shaped object 2 and the peripheral wall 2a of the second stacked container-shaped object 2, and air flows in. be done. By distorting the first object 2, an air inflow path is formed. The friction body 30 is arranged at a position that overlaps the upper end 2b, and the friction body 30 pushes the upper end 2b outward to deform it, thereby making it easier to form a gap that serves as an inflow path for air. Therefore, by forming the air inflow path in this way, the occurrence of negative pressure between both peripheral walls 2a is suppressed, and negative pressure occurs between both peripheral walls 2a. It is possible to prevent the container-shaped object 2 and the second container-shaped object 2 from being picked up together, or the second container-shaped object 2 from being lifted up and tilted or falling. . Further, when the friction body 30 expands the peripheral wall 2a in the radial direction with the guide member 18 abutting against the upper end 2b, the friction body 30 expands the upper end 2b of the object 2, so that the top first container It is possible to make it easier for air to enter between the shaped object 2 and the second container-shaped object 2 from the upper end part, and it is possible to further prevent the two from being picked up together.

Next, the controller 20 moves the object 2 below the object 2 by withdrawing the hand 1 upward while the plurality of fingers 14 deform the circumferential wall 2a of the object 2 by the friction bodies 30 in the radial direction. A process of separating and picking up the stacked object 2 is executed. With the friction bodies 30 in contact with the inner surface of the peripheral wall 2 a of the object 2 , the friction bodies 30 can hold and lift only the top object 2 . In addition, the second container-shaped object 2 is pulled upward or obliquely by the first container-shaped object 2 under negative pressure, and the second container-shaped object 2 tilts or floats (the support rod 9 is Even if there is a support rod 9, there is a possibility that the object 2 will tilt, etc.), or the object group (container group) itself in a state in which a plurality of objects are stacked will tilt (even if there is a support rod 9, the object group may tilt, etc.). ), movement can also be suppressed. Therefore, it is possible to prevent the hand 1 from failing to pick up the object 2 from the next time onward. Although the hand 1 is described as picking up the stacked object 2, the hand 1 can also pick up, hold, and move the unstacked object 2. FIG. The hand 1 holds the object 2 in an unstacked state and can also change its position and modify it.

Next, the control device 20 moves the hand 1 above the placement target 10 and moves the object 2 above the placement target 10 while the friction body 30 holds the object 2 from the inside. At this time, the upper end of the object 2 is in contact with the contact element 28, and the object 2 can be relatively stably and easily moved. The control device 20 moves the object 2 to a predetermined position on the placement target 10 based on the position of the placement target 10 recognized by a camera or the like. The controller 20 places the object 2 on the placement object 10 with the friction body 30 holding the object 2, and actuates the fingers 14 and the friction body 30 to the closed state. At this time, the hand 1 can perform the placement operation while moving in the same direction at a speed synchronized with the conveyor belt 8 . When the object 2 is placed on the placement object 10, the control device 20 raises the hand 1 and returns to the standby state.

According to the hand 1 according to the first embodiment of the present invention described above, the guide member 18 can define the relative height relationship between the object 2 and the plurality of fingers 14, and the friction body 30 can The position acting on the inner surface of the peripheral wall 2a of 2 can be defined relatively stably. Friction bodies 30 provided in each of 14 apply static friction force to the inner surface of the peripheral wall 2a of the object 2 to be held, so that the object 2 having the peripheral wall 2a with an open upper side can be held. Further, according to the configuration of the present embodiment, for example, from a state in which a plurality of objects 2 having peripheral walls 2a whose upper sides are open are placed one on top of the other, the object 2 having peripheral walls 2a whose upper sides are open is separated into one. You can pick it up and hold it.

Furthermore, according to the hand 1 of the present embodiment, the friction body 30 is formed so as to cover the entire peripheral surface of each finger 14 and is a cylindrical member made of a viscoelastic material. When the position acting on the object 2 to be held is changed by a slight movement of the object 2 to be held, or the position at which the friction body 30 acts on the object 2 to be held varies depending on the shape and size of the object 2 itself to be held. , the friction body 30 of each of the plurality of fingers 14 can easily apply a static frictional force to the inner surface of the peripheral wall 2a of the object 2 to be held, and the peripheral wall 2a whose upper side is open can be easily applied. The object 2 can be held more reliably. In addition, the friction body 30 can easily hold the object 2 in response to, for example, a difference in shape due to a manufacturing error of the object 2 and a difference in shape such as variations in the shape of the object 2 .

Furthermore, according to the hand 1 of this embodiment, the guide member 18 has a plurality of abutment elements 28 that abut against the upper end of the peripheral wall 2a of the object 2 to be held at a plurality of points. adjusts the relative height relationship between the object 2 and the fingers 14 at a plurality of points, and the guide member 18 defines the relative height relationship between the object 2 and the plurality of fingers 14 more stably. The contact position of the friction body 30 with the peripheral wall 2a of the object 2 can be more stably defined.

Furthermore, according to the hand 1 of the present embodiment, each of the plurality of contact elements 28 is arranged at a position not overlapping each of the plurality of fingers 14 when viewed in the radial direction. Each of the plurality of fingers 14 is prevented from interfering with the friction body 30 attached to 14, and the guide member 18 stably regulates the relative height relationship between the object 2 and the plurality of fingers 14. Frictional body 30 exerts a static frictional force on the inner surface of the peripheral wall 2a of the object 2 to be held, so that the object 2 having the peripheral wall 2a with an open upper side can be held more reliably.

Furthermore, according to the hand 1 of the present embodiment, the actuator 16 is configured to radially move the plurality of fingers 14 while maintaining the rotational symmetry of the plurality of fingers 14 . As a result, the friction bodies 30 of each of the plurality of fingers 14 are moved in the radial direction while maintaining rotational symmetry, and are located at positions having rotational symmetry with respect to the inner surface of the annular peripheral wall 2a of the object 2, for example. A static frictional force can be applied to make it easier to hold the object 2 in a well-balanced manner, and to make it easier to hold an object 2 having, for example, an annular peripheral wall 2a.

Further, according to the hand 1 of the present embodiment, the plurality of fingers 14 are moved radially outward relative to each other in a state in which the guide member 18 is abutted against the upper end of the peripheral wall 2a by the step of creating the gap. , contacting the inner surface of the peripheral wall 2a and further deforming the peripheral wall 2a in the radial direction. In a state where the plurality of fingers 14 deform the peripheral wall 2a of the container (object 2) in the radial direction by the step of creating a gap with the peripheral wall 2a of the container (object 2) and picking up, the hand is moved. 1 is retracted upward, the container (object 2) is separated from the container (object 2) stacked below the container (object 2) and picked up. As a result, from a state in which a plurality of flexible containers (objects 2) having a peripheral wall 2a with an open upper side are stacked, the containers (objects 2) are picked up one by one using the static frictional force on the inner surface of the peripheral wall 2a. be able to.

Next, a hand according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. FIG. The second embodiment is an example in which the hand guide member according to the present invention is formed in a different shape. FIG. 7 is a top view of a hand according to a second embodiment of the present invention, FIG. 8 is a side view of the two arm portions of the guide member of the hand of FIG. FIG. 8 is a front view of the two-divided arm portion of the guide member of the hand of FIG. 7 as seen from the front side; Since the hand according to the second embodiment has substantially the same structure as the hand according to the first embodiment described above, only the points that differ from the first embodiment of the second embodiment of the present invention will be described, and the same parts will be explained. are denoted by reference numerals, and illustration and description thereof are omitted.

A hand 101 of the second embodiment holds an object 2 to be held. A hand 101 of this embodiment is provided in a holding system 4 that holds an object 2 .

The hand 101 holds the object 2 using static frictional force against the inner surface of the peripheral wall 2a. The hand 101 picks up and holds the objects 2 one by one from a state in which a plurality of the objects 2 are stacked, and conveys the objects 2 to a specific position on the placement object 10 on the conveyor belt 8 .

The hand 101 is provided at a predetermined relative height position with respect to the fingers 14, the actuator 16, and the plurality of fingers 14, and hits the upper end of the peripheral wall 2a of the object 2 to be held, thereby holding the object 2. and a guide member 18 that defines the relative height relationship between the plurality of fingers 14, and a peripheral wall 2a of the object 2 to be held, which is provided at a predetermined relative height position with respect to the plurality of fingers 14. a guide member 118 that impinges on the upper end of the guide member 118 to define the relative height relationship between the object 2 and the plurality of fingers 14;

The guide member 18 includes an arm portion 26 that extends radially outward from the side of the actuator 16 and then hangs downward from an outer end portion, and an arm portion 26 that is provided at the tip of the arm portion 26 to hold an object to be held. It has a plurality of abutment elements 28 which abut against the upper edge 2b of the peripheral wall 2a of the object 2 at a plurality of points.

The guide member 118 extends substantially horizontally outward in the radial direction from the side of the actuator 16, and is divided into two parts. It has a hanging Y-shaped arm portion 126 and contact elements 128 provided at the tip of the arm portion 126 and abutting against the upper end 2b of the peripheral wall 2a of the object 2 to be held at a plurality of points. The guide member 118 has the function of stabilizing the posture of the object 2 to be picked up, and also has the function of positioning the friction body 30 at a position where it overlaps the upper end of the object 2 as will be described later. The guide member 118 may also have the function of guiding and stabilizing the attitude and relative positional relationship of the actuator 16 and the fingers 14 with respect to the object 2 . In addition, the guide member 118 can correct the inclination and floating of the second and subsequent objects 2 from the top of the stacked objects 2 to make the stacked objects 2 extend vertically.

Each of the plurality of arm portions 26 and arm portions 126 and each of the plurality of contact elements 28 and 128 are arranged at positions not overlapping each of the plurality of fingers 14 when viewed in the radial direction. Further, each of the plurality of arm portions 26 and arm portions 126 and each of the plurality of contact elements 28 and 128 are provided between each of the fingers 14 in the circumferential direction when viewed from above. Arm portion 126 and abutment element 128 are arranged symmetrically about the centerline.

Each of the abutment elements 128 is arranged so as to correspond to a position on the upper end 2b, the upper end 2b being in contact with a plurality of abutment elements 128 and the abutment elements 28, so that the position, orientation and/or It stabilizes the tilt and makes it easier to adjust. The lower surface of the contact element 28 is formed in a narrow plate shape, but may be formed by a circular contact surface or the like. Further, the lower surface of the contact element 128 is formed by a circular contact surface or the like, but may be formed in a plate shape such as a narrow width. Abutment element 28 and abutment element 128 are arranged in the same horizontal plane, ie at the same height. Therefore, when the abutment element 28 and the abutment element 128 abut against the upper end 2b of the object 2, the relative height relationship between the object 2 and the plurality of fingers 14 (friction bodies 30) is Since it is the same as the relative height relationship between the object 2 and the plurality of fingers 14 (friction bodies 30) in the form, the description is omitted. In this embodiment, the hand 101 includes one guide member 18 and two guide members 118. However, for example, the guide member 18 may be omitted and three or more guide members 118 may be provided. Also, for example, more than one guide member 18 may be provided and more than one guide member 118 may be provided.
Note that the operation (action) of the hand 101 according to the second embodiment of the present invention is basically the same as the operation (action) of the hand 1 according to the first embodiment, so the explanation is omitted.

1 hand 2 object 2a peripheral wall 2b upper end 14 finger 14a peripheral surface 16 actuator 18 guide member 28 contact element 30 friction body 101 hand 118 guide member 128 contact element

Claims (6)

A hand that holds an object having a peripheral wall with an open upper side by using a static frictional force against the inner surface of the peripheral wall,
a plurality of fingers of three or more discretely arranged in the circumferential direction;
connected to the plurality of fingers and configured to move the plurality of fingers apart radially outwardly away from one another and move back radially inwardly toward one another; an actuator;
Provided at a predetermined relative height position with respect to the plurality of fingers, and abutting against the upper end of the peripheral wall of the object to be held, the relative height relationship between the object and the plurality of fingers a guide member that defines
with
A hand, wherein each of the plurality of fingers has a friction body that exerts a static frictional force on the inner surface of the peripheral wall of the object to be held, on at least the radially outer surface thereof. 2. A hand according to claim 1, wherein said friction body is a tubular member formed of a viscoelastic material and formed so as to cover the entire peripheral surface of each finger. 3. A hand according to claim 1, wherein said guide member has a plurality of abutment elements that abut against said upper end of said peripheral wall of said object to be held at a plurality of points. 4. A hand according to claim 3, wherein each of said plurality of abutment elements is arranged at a position not overlapping each of said plurality of fingers when viewed in the radial direction. The plurality of fingers are arranged at equal intervals in the circumferential direction so as to have rotational symmetry,
5. The actuator according to any one of claims 1 to 4, wherein the actuator is configured to radially move the plurality of fingers while maintaining rotational symmetry of the plurality of fingers. hand. A method of picking up the containers one by one from a state in which a plurality of flexible containers each having a peripheral wall with an open upper side are stacked, using a static frictional force against the inner surface of the peripheral wall, the method comprising:
a plurality of fingers of three or more discretely arranged in the circumferential direction;
connected to the plurality of fingers and configured to move the plurality of fingers apart radially outwardly away from one another and move back radially inwardly toward one another; an actuator;
Provided at a predetermined relative height position with respect to the plurality of fingers, and abutting against an upper end of a peripheral wall of a container to be held, the relative height relationship between the container and the plurality of fingers a guide member that defines
with
Each of the plurality of fingers has a friction body that exerts a static frictional force on the inner surface of the peripheral wall of the container to be held, on at least the radially outer surface thereof. Use,
a step of bringing the hand closer to the container to be held from above the container and abutting the guide member against the upper end of the peripheral wall of the container;
In a state in which the guide member is abutted against the upper end of the peripheral wall, the plurality of fingers are moved radially outward to expand away from each other and contact the inner surface of the peripheral wall. a step of radially deforming the peripheral wall to create a gap between the peripheral wall of the container and the peripheral wall of the container stacked below the container by the deformation;
With the plurality of fingers deforming the peripheral wall of the container in the radial direction, the hand is retracted upward, thereby separating the container from the container stacked below the container and picking up the container. and
A method comprising:

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