Robotic hand for palletizing device

Abstract

To provide a robot hand that eliminates the need of actively space between adjacent two objects to be carried to stack objects to be carried.SOLUTION: A robotic hand 1 includes two fingers 2 and 3 including engagement parts 2A and 2B respectively having a linear shape to be fitted to a recess 103 provided in a pair of side wall parts 101 of a container 100. Adjacent parts 2C and 3C adjacent to the engagement parts 2A and 2B of the two fingers 2 and 3 have an inclined shape that is defined so as to be capable of pulling out the fingers from a clearance formed between adjacent two foldable type containers when a floating mechanism 6 transitions to a non-fixed state and a fork 4 moves in a direction of separating from the container 100.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a robot hand of a palletizing device that holds and conveys an object to be conveyed by a fork having fingers.

Background Art

[0002] There is a robot hand of a palletizing device of a type in which a suction device is provided on the robot hand, the object to be conveyed is sucked by the suction device and conveyed, and the suction of the suction device is released when stacking the objects to be conveyed. This type of robot hand has no particular problem when the weight of the object to be conveyed is light or when the shape of the object to be conveyed is suitable for suction. However, when the weight of the object to be conveyed becomes heavy or when the shape of the object to be conveyed is unsuitable for suction, the robot hand equipped with a suction device cannot be used.

[0003] To address such problems, a robot hand of a palletizing device of a type that holds and conveys an object to be conveyed (a box in the shape of a cube) by a fork having two fingers, like the robot hand shown in FIG. 8 of Japanese Patent Application Laid-Open No. 2003-159688 (Patent Document 1), is used. In this robot hand, the object to be conveyed is supported from below by two fingers and conveyed. When stacking the objects to be conveyed, the robot hand is tilted from a predetermined height position above the object to be conveyed below to drop the object to be conveyed. With this robot hand, it is difficult to accurately stack the objects to be conveyed.

[0004] In addition, Japanese Patent Application Laid-Open No. 2023-170088 (Patent Document 2) discloses an example of a robot hand of a palletizing device that sandwiches an object to be conveyed (a cubic box) from both sides with two fingers and stacks them. In the robot hand described in this publication, after placing the object to be conveyed sandwiched by the two fingers on the object to be conveyed that is being stacked, while raising one finger located on the other object to be conveyed side upward, the object to be conveyed is pushed toward the other object to be conveyed on which the object to be conveyed has already been placed by the other finger, thereby reducing the distance between the two conveyed objects. However, in this robot hand, the structure for driving the two fingers becomes complicated.

[0005] Conventionally, as shown in FIGS. 7(A) and (B), when conveying an object to be conveyed having a protrusion 102 serving as an engaged portion that linearly extends at the upper ends of a pair of opposing side wall portions 101, such as a foldable container 100, a robot hand 12 having a pair of plate-shaped fingers 11 provided with a pair of engaging portions 11a at the tips that engage with the pair of protrusions (engaged portions) 102 has been proposed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the conventional robot hand 12 shown in FIG. 7, even when attempting to stack each container 100 that is an object to be conveyed, in order to remove the engaging portion 11a of the finger 11 from the protrusion (engaged portion) 102 of the container 100, it was necessary to secure a sufficient gap for pulling out the finger 11 between two adjacent containers.

[0008] An object of the present invention is to provide a robot hand that does not need to actively create a large gap between two adjacent objects to be conveyed in order to stack the objects to be conveyed.

Means for Solving the Problems

[0009] The present invention is directed to a robot hand of a palletizing device that holds and conveys an object to be conveyed by a fork having one or more pairs of fingers. Each of the one or more pairs of fingers includes an engaging portion that engages with the object to be conveyed and a connecting portion that connects the engaging portion to a floating mechanism. Adjacent portions of each of the connecting portions of the one or more pairs of fingers adjacent to the engaging portion have an inclined shape that inclines in a direction away from each other as they go from the engaging portion side toward the connecting portion. According to the present invention, by appropriately determining the inclination angle of the inclined shape of the adjacent portions of the one or more pairs of fingers, even if there is an obstacle structure around the portion where the engaging portion is engaged, the adjacent portions of the inclined shape can smoothly overcome the obstacle structure and pull out the engaging portion of the finger from between two adjacent objects to be conveyed.

[0010] When the object to be conveyed is an object to be conveyed provided with a pair of recesses that open outward on the outer surfaces of a pair of opposing side wall portions, the engaging portions of the one or more pairs of fingers preferably each have a linear shape that fits into the recesses. And the inclined shape of the adjacent portions of each of the connecting portions of the one or more pairs of fingers adjacent to the engaging portion allows the engaging portion to fit into the recess when the floating mechanism is in a non-fixed state and the fork moves in the direction toward the object to be conveyed, and after the floating mechanism becomes fixed with the engaging portion fitted into the recess and the object to be conveyed is conveyed to a predetermined position, when the floating mechanism shifts to a non-fixed state and the fork moves in the direction away from the object to be conveyed, it is preferably defined so as to allow the engaging portion to come out of the recess. By doing so, even if the corner portions existing around the recess become obstacle structures, the inclination of the adjacent portions of the finger serves as a guide and the engaging portion smoothly overcomes the corner portion. Therefore, the pulling out of the robot hand can be performed smoothly.

[0011] The object to be conveyed may have a pair of recesses that open outwardly on the outer surfaces of a pair of opposing side wall portions. Representative objects to be conveyed having such characteristics include foldable containers and cases for transporting beer, etc.

[0012] Even when the object to be conveyed has a projecting portion that protrudes outward from a pair of side wall portions at its upper edge and two adjacent objects to be conveyed are stacked with the projecting portions in proximity, when the floating mechanism shifts to a non-fixed state and the forks move in a direction to be pulled away from the object to be conveyed, if the inclination angle and length of the inclined shape of the adjacent portions of the two fingers are determined such that the two fingers can be pulled out from the gap formed between the two adjacent objects to be conveyed, the fingers can be pulled out without any problem even when the two adjacent objects to be conveyed are stacked in the closest proximity.

[0013] When using the robot hand of the present invention, after fitting the engaging portions of one or more pairs of fingers into the pair of recesses of the object to be conveyed to fix the floating mechanism, the object to be conveyed is transported to a predetermined position and placed at the predetermined position. Next, the floating mechanism is made non-fixed, and the forks are moved in a direction from the engaging portion toward the connecting portion to pull out the engaging portion from the recess. When pulling out the engaging portion from the recess, the inclination of the adjacent portion of the finger serves as a guide, and the engaging portion smoothly gets over the corner portion of the recess. Therefore, the fingers of the robot hand can be pulled out smoothly.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a perspective view of the robot hand 1 of the present embodiment, and FIGS. 2 (A) to (C) show the clamp open state, the clamp close state, and the finger pull-out state of the actual robot hand 1 shown in FIG. 1 as viewed from the bottom side. FIGS. 5 (A) to (C) are a side view, a front view, and a bottom view which simulatedly show the state which hold | maintained the folding container 100 as a conveyance object with the robot hand 1.

[0016] The robot hand 1 holds the folding container 100 as a conveyance object with the fork 4 provided with a pair of fingers 2 and 3. The fork 4 is held by the fork holding part 5. The fork holding part 5 which holds the fork 4 provided with a pair of fingers 2 and 3 is provided with the floating mechanism 6 which selects the fixed state which fixes after changing the space | interval of two fingers 2 and 3, and the non-fixed state which allows displacement of the space | interval of a pair of fingers 2 and 3 according to a command.

[0017] The pair of fingers 2 and 3 each include engaging portions 2A and 3A that engage with the container 100 and connecting portions 2B and 3B that connect the engaging portions 2A and 3A to the floating mechanism 6. The pair of fingers 2 and 3 have adjacent portions 2C and 3C adjacent to the engaging portions 2A and 3A of the connecting portions 2B and 3B. These adjacent portions 2C and 3C have an inclined shape that slopes away from each other as they extend from the engaging portions 2A and 3A side toward the connecting portions 2B and 3B. This inclined shape will be described later.

[0018] The fork holding portion 5 includes a floating mechanism 6 on the back side of a plate-like base 51 that is attached to an arm of a palletizing device (not shown). As shown in FIGS. 2(A) to (C), the floating mechanism 6 includes a pair of guide rails 61 and 62 that are fixed to the base 51 and extend in parallel, and a pair of finger supports 63 and 64 that are slidably supported via pulleys 70 on the pair of guide rails 61 and 62 and support the pair of fingers 2 and 3. Further, the floating mechanism 6 includes a drive mechanism 65 [FIG. 2(A)] that slides the pair of finger supports 63 and 64 with respect to the pair of guide rails 61 and 62 in response to an operation command and selectively creates a fixed state and a non-fixed state. The drive mechanism 65 includes drive sources 66 and 67 that are drive air cylinders, and a pair of link mechanisms 68 and 69 that are driven by these drive sources 66 and 67. The drive sources 66 and 67 are fixed to the pair of finger supports 63 and 64. The pair of link mechanisms 68 and 69 include a pair of first links 68a and 69a that are slidably attached to the finger supports 63 and 64 in the front-rear direction and are moved back and forth by the drive sources 66 and 67, and a pair of second links 68d and 69d in which a pair of guide grooves 68c and 69c into which a pair of pin members 68b and 69b provided at the tip ends of the pair of first links 68a and 69a are fitted are respectively formed. The second links 68d and 69d are fixed to cylinder rods 68e and 69e of a pair of air cylinders that move the second links 68d and 69d in the left-right direction.

[0019] As shown in Fig. 3(A), when the pin members 68b and 69b are in a fitted state in the narrow portions within the pair of guide grooves 68c and 69c provided in the pair of second links 68d and 69d, the pin members 68b and 69b cannot move in the left-right direction. As a result, in this state, the pair of finger supports 63 and 64, to which the first links 68a and 69a are fixed, move left and right according to the movement of the pair of cylinder rods 68e and 69e. The state of Fig. 2(A) is a state in which the pair of cylinder rods 68e and 69e extend in the left-right direction, the second links 68d and 69d move outward in the left-right direction, and the distance between the pair of finger supports 63 and 64 is the widest (clamp open state). And the state of Fig. 2(B) is a state in which the pair of cylinder rods 68e and 69e are contracted in the left-right direction, and the distance between the pair of finger supports 63 and 64 is the narrowest (clamp close state). In the state of Fig. 2(C), the drive sources 66 and 67 are driven and the pair of first links 68a and 69a move in the front-rear direction. In this state, the pair of pin members 68b and 69b provided on the pair of first links 68a and 69a move to the wide portions within the pair of guide grooves 68c and 69c as shown in Fig. 3(B). In this state, a floating state is configured in which the pair of first links 68a and 69a (the pair of finger supports 63 and 64) can move freely within a predetermined movable range in the left-right direction (finger pulling-out state). This predetermined movable range is defined by the left-right direction length dimension of the wide portions of the pair of guide grooves 68c and 69c.

[0020] By providing the floating mechanism 6 configured in this manner, it is possible to create a fixed state in which the pair of fingers 2 and 3 are fixed so as not to move freely left and right, and to create a non-fixed state in which the restraint (fixation) of the pair of fingers 2 and 3 is released and the pair of fingers 2 and 3 can move freely left and right. FIG. 4 is a diagram showing an example of the foldable container 100 as an object to be conveyed by the robot hand 1. As shown in FIG. 4, the foldable container 100 has a protruding portion 102 that protrudes outward from a pair of side wall portions 101 at the upper edge portion, and a pair of recesses 103 that open outward are provided on the outer surfaces of the pair of opposing side wall portions 101. When the object to be conveyed is such a foldable container 100, two adjacent foldable containers 100 stacked on top of each other are stacked in a state where the protruding portions 102 are close to each other.

[0021] As shown in FIGS. 5(A) to (C), in the present embodiment, the engaging portions 2A and 3A of the pair of fingers 2 and 3 have a linear shape having a length and a width that are respectively fitted into the recesses 103. As shown in FIGS. 6(A) and (B), the corner portion 104 of the inner wall of the recess 103 serves as an obstacle structure when the engaging portions 2A and 3A enter the recess 103 and the engaging portions 2A and 3A come out of the recess 103. Therefore, in the present embodiment, as shown in FIG. 6(B), the inclination angle θ and the length L of the inclined shapes of the adjacent portions 2C and 3C adjacent to the connecting portions 2B and 3B of the fingers 2 and 3 are such that the engaging portions 2A and 3A of the fingers 2 and 3 can smoothly overcome the corner portion 104 when the engaging portions 2A and 3A are pulled out of the recess 103.

[0022] In other words, in the present embodiment, the inclination angle θ and the length L of the inclined shapes of the adjacent portions 2C and 3C of the two fingers 2 and 3 respectively allow the engaging portions 2A and 3A to be fitted into the recess 103 when the floating mechanism 6 is in a non-fixed state and the fork 4 moves in the direction toward the object to be conveyed, and in a state where the engaging portions 2A and 3A are fitted into the recess 103, after the floating mechanism 6 becomes fixed (clamp closed state) and the container 100 as the object to be conveyed is conveyed to a predetermined position, when the floating mechanism 6 shifts to a non-fixed state (finger pulling-out state) and the fork 4 moves in the direction of being separated from the container 100, it is defined so as to allow the engaging portions 2A and 3A to come out of the recess 103 and the fingers 2 and 3 to come out of the gap between the adjacent containers 100.

[0023] Specifically, in the present embodiment, when the dimension G between the protruding portions 102, 102 (FIG. 6(A)) on the outer periphery of the upper end of the adjacent containers of the container is about 6 mm and the pair of intervals G1 (FIG. 6(B)) between the side wall portions of the adjacent containers 100, 100 is 8 mm, the inclination angle θ of the adjacent portions 2C, 3C is defined so that the angle θ between the virtual line PL1 extending along the linearly extending engaging portions 2A and 3A and the virtual line PL2 extending along the adjacent portions 2C, 3C becomes about 6 degrees. Also, the length L of the adjacent portions 2C, 3C is about 600 mm. By doing so, even when two adjacent foldable containers are stacked in the closest state with the protruding portions 102 facing each other, when pulling out the fork 4, the engaging portions 2A, 3A of the fingers 2 and 3 can smoothly cross over the corner portions 104 around the recess 103 along the inclined shape of the adjacent portions 2C, 3C, so that the pulling out of the robot hand can be performed smoothly. Note that this angle θ and length L are determined by the depth of the recess 103 and the dimension of the interval G between the opposing side wall portions of the two adjacent containers 100, 100, so the present invention is not limited to the specific numerical values of this embodiment.

[0024] The floating mechanism 6 used in the above embodiment is an example, and the present invention is not limited to the floating mechanism 6 used in this embodiment.

[0025] In the above embodiment, the foldable container is described as an example of the object to be conveyed. However, since the present invention is suitable for conveying an object to be conveyed having recesses in a pair of side wall portions in the same manner as the foldable container, the object to be conveyed is not limited to the foldable container. For example, a beer transport case or the like is also an object to be conveyed having recesses in a pair of side wall portions.

[0026] In addition, the pair or more of fingers also includes two pairs of fingers arranged apart in the vertical direction. When using two pairs of fingers, a floating mechanism 6 may be provided for each pair of fingers.

Industrial Applicability

[0027] According to the present invention, by appropriately determining the inclination angle of the inclined shape of the adjacent portion adjacent to the connecting portion of the pair of fingers, the pair of engaging portions can be smoothly pulled out from between two adjacent objects to be conveyed.

Explanation of Reference Numerals

[0028] 1 Robot hand 2, 3 Fingers 2A, 3A Engaging portions 2B, 3B Connecting portions 2C, 3C Adjacent portions 4 Fork 5 Fork holding portion 6 Floating mechanism 100 Foldable container 102 Protrusion 103 Recess 104 Corner portion

Claims

1. A robot hand of a palletizing device that holds and transports an object using a fork having one or more pairs of fingers, a fork holding portion that holds the one or more fingers of the fork has a floating mechanism that can selectively be in a fixed state in which the spacing between the one or more fingers is changed and fixed, and in an unfixed state in which the spacing is freely changed, each of the pair or more fingers includes an engagement portion that engages with the object to be transported and a connecting portion that connects the engagement portion to the floating mechanism; A robot hand of a palletizing device, characterized in that adjacent portions of the connecting portions of each of the one or more pairs of fingers adjacent to the engaging portions have inclined shapes that incline in directions away from each other as they move from the engaging portions toward the connecting portions.

2. the load includes a pair of recesses that are provided on outer surfaces of a pair of opposing side walls and open outward; the engaging portions of the at least one pair of fingers each have a linear shape that is fitted into the recess, 2. The robot hand of a palletizing device according to claim 1, wherein the inclination shape and length of the adjacent portion are determined so as to allow the engagement portion to fit into the recess when the floating mechanism is in the non-fixed state and the fork moves in a direction toward the transported object, and to allow the engagement portion to come out of the recess when the floating mechanism is in the fixed state with the engagement portion fitted into the recess and the transported object is transported to a predetermined position, and then the floating mechanism is in the non-fixed state and the fork moves in a direction away from the transported object.

3. 3. The robot hand of a palletizing device according to claim 2, wherein the transported object has a protrusion formed above the recess that protrudes outward beyond the side wall portion, and when two of the transported objects are arranged with the protrusions close to each other, the inclination angle and length of the inclination shape of the adjacent portions of the pair of fingers are determined so that when the floating mechanism transitions to the non-fixed state and the forks move in a direction away from the transported objects, the one or more fingers can be pulled out from a gap formed between the two adjacent side wall portions of the two adjacent transported objects.

4. The one or more pairs of fingers are a pair of fingers extending in a horizontal direction, The fork holder has a structure in which the floating mechanism is provided on a base supported by a robot arm, 4. The robot hand of a palletizing device according to claim 1, wherein the floating mechanism comprises: a pair of guide rails fixed to the base and extending in parallel; a pair of finger supports slidably supported on the pair of guide rails and equipped with the pair of forks; and a drive mechanism that slides the pair of finger supports relative to the pair of guide rails in response to an operation command and selectively creates the fixed state and the non-fixed state.

5. A method for using the robot hand of the palletizing device according to claim 1, comprising: the load is provided with a pair of recesses that are provided on outer surfaces of a pair of opposing side walls and open outward, the engaging portions of the at least one pair of fingers are fitted into the pair of recesses to fix the floating mechanism in the fixed state, and then the object is transported to a predetermined position and placed at the predetermined position; A method of using a robot hand of a palletizing device, characterized in that the floating mechanism is then placed in the non-fixed state, and the fork is moved in a direction from the engagement portion toward the connection portion, thereby pulling the engagement portion out of the recess.

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