JP2020116683A - Holding mechanism and carrying device - Google Patents

Abstract

To provide a holding mechanism, whose structure can be simplified and which can reduce time required for moving pressing members in an anti-vibration mechanism.SOLUTION: A holding mechanism (1) comprises an adsorption part (3) that adsorbs an upper surface of an article (W) and an anti-vibration mechanism (8) that restricts vibration of the article held by the adsorption part when the holding mechanism moves in a horizontal direction. The anti-vibration mechanism comprises: pressing members (10) that contact the article adsorbed by the adsorption part to apply at least pressing force generated by own weight to the article; a guide member (20) that supports the pressing members so that the members can move relatively in a vertical direction; a fixing part (30) that restricts movement of the pressing members by displacing the guide member; and a switching part (40) that switches between a movement restricted state and a movable state of the pressing members by the fixing part.SELECTED DRAWING: Figure 2

Description

The present invention relates to a holding mechanism and a carrying device, and more particularly to a holding mechanism and a carrying device used for holding and carrying an article.

Conventionally, for example, a robot hand disclosed in Patent Document 1 has been proposed to convey various articles. The robot hand of Patent Document 1 is attached to the tip of a robot arm, and includes a suction pad and a fixed rod arranged outside the suction pad. In Patent Document 1, the fixed rod moves up and down by a small uniaxial servomotor according to the inclination of the work held by the suction pad, and the work can be conveyed while preventing the work from tilting beyond a certain level.

JP, 9-262785, A

In Patent Document 1, a servomotor is indispensable for moving the fixed rod up and down, and since the same number of such servomotors as the fixed rods are installed, the structure of the robot hand becomes complicated. Further, when the fixed rod is moved by the servomotor, it is necessary to stop the movement after moving the fixed rod to a position where the fixed rod contacts the workpiece sucked by the suction pad. Therefore, it is necessary to detect the position of the work with a sensor or a camera, perform image recognition, or detect the force applied to the fixed rod with a force sensor, which also complicates the structure and There is a problem that it takes a long time to correct the position of the fixed rod, which lowers the transportation efficiency.

The present invention has been made in view of the above points, and provides a holding mechanism and a transfer device that can simplify the structure and reduce the time required to move the pressing member in the steady rest mechanism. One of the purposes is to do.

A holding mechanism according to one aspect of the present invention is a holding mechanism that holds an article by suction from an upper surface side, and is held by the suction section that sucks the upper surface of the article and the suction section when the holding mechanism moves in the horizontal direction. A steadying mechanism for restricting a shake of the article due to the movement, the steadying mechanism abutting against the article sucked by the suction section and applying a pressing force at least by its own weight; A guide member that supports the guide member so as to be relatively movable in a direction, a fixed portion that restricts the movement of the pressing member by displacing the guide member, and a switching that switches between a movement restricting state and a movable state of the pressing member by the fixing portion. And a section.

A carrying device according to one aspect of the present invention is characterized by including the holding mechanism and a moving mechanism capable of carrying the suction-held article by moving the holding mechanism in a horizontal direction.

According to the present invention, the pressing member can apply a pressing force to the article adsorbed by the adsorbing unit by its own weight, and in this state, the switching of the switching unit restricts the movement of the pressing member by the fixing unit and the pressing member. Can be kept in contact with the article. This makes it possible to omit a conventional servomotor that moves the rod in the vertical direction, and bring the holding mechanism close to the top of the article without detecting the position of the article so that the pressing member can be brought into contact with the top surface of the article. It can be omitted and the structure can be simplified. Moreover, since it is not necessary to detect the position of the article, it is possible to eliminate the position detection and correction of the position of the pressing member based on the detection result, and to reduce the time required to move the pressing member when restricting the shake by the steady rest mechanism. As a result, it is possible to shorten the transportation time of the article held by the holding mechanism.

It is a schematic perspective view of the holding mechanism which concerns on embodiment. It is a schematic front view of the holding mechanism which concerns on embodiment. It is a bottom view of the holding mechanism concerning an embodiment. FIG. 4A is a partial front cross-sectional view of the holding mechanism according to the embodiment, and FIG. 4B is an operation explanatory view of the fixing portion in FIG. 4A. 5A is a schematic perspective view of a first ring of the fixing portion, FIG. 5B is a schematic perspective view of a second ring of the fixing portion, FIG. 5C is an exploded front sectional view of the fixing portion, and FIG. [Fig. 4] is a front sectional view of a fixed part. It is an explanatory view of control of compressed air of a holding mechanism in an embodiment. It is explanatory drawing of an adsorption process. It is explanatory drawing of an adsorption process. It is explanatory drawing of a transfer process. It is explanatory drawing of a transfer process. It is explanatory drawing of a transfer process. It is explanatory drawing of a transfer process.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following embodiments, and can be carried out by appropriately modifying it without departing from the scope of the invention. In the following figures, a part of the configuration may be omitted for convenience of description. Further, in the following description, unless otherwise specified, “upper”, “lower”, “left”, “right”, “front”, and “rear” are based on the directions indicated by arrows in the drawings. However, the orientation of each component is merely an example and can be changed to any orientation.

FIG. 1 is a schematic perspective view of a holding mechanism according to an embodiment. FIG. 2 is a schematic front view of the holding mechanism according to the embodiment. As shown in FIGS. 1 and 2, the holding mechanism 1 includes a base plate 2 having a substantially circular plate shape and oriented in a horizontal direction, and a suction portion 3 (provided in an in-plane central region on the lower surface side of the base plate 2). (Not shown in FIG. 1). A plate-shaped robot connecting portion 5 oriented in the horizontal direction is connected to the upper surface side of the base plate 2 via a plurality of support rods 6. The robot connecting portion 5 is a portion connected to a robot arm such as an articulated arm (not shown) in the transfer device, a biaxial or triaxial moving device, a moving mechanism such as a rail, and holds and conveys the article W. Used for. Therefore, the carrying device can be configured by including the holding mechanism 1 of the present embodiment and the moving mechanism.

Here, the article W held by the holding mechanism 1 of the present embodiment is, as an example, a lunch box container having a substantially circular shape in a top view. The article W of the present embodiment includes a lower housing portion Wa and a lid portion Wb that closes the upper portion of the housing portion Wa. On the side surface of the article W and on the outer peripheral side of the lid portion Wb, a collar portion Wc is formed so as to project outward. The side surface of the lid portion Wb is formed by a tapered inclined surface that widens downward from the upper end.

The suction unit 3 is provided below the base plate 2 and includes a plurality of suction pads 3a having a suction cup shape or a bellows shape. FIG. 3 is a bottom view of the holding mechanism according to the embodiment. As shown in FIG. 3, in the suction unit 3 of the present embodiment, suction pads 3a are provided side by side at four positions in the front and rear and in the left and right. A hose (not shown) that communicates with an ejector or the like (suction source) described below is connected to each suction pad 3a, and suction through them causes negative pressure to be generated on the suction surface, which is the lower surface of the suction pad 3a. Can be adsorbed and held from the upper surface side.

Returning to FIG. 1 and FIG. 2, the holding mechanism 1 further includes a steady rest mechanism 8 for the article W suction-held by the suction unit 3. The steady rest mechanism 8 includes a plurality of holding members 10 and a plurality of guide members 20 provided on each of the plurality of holding members 10. Specifically, the pressing members 10 are provided at a total of four positions on the base plate 2, that is, two positions in the front and rear and two positions in the left and right, and each guide member 20 supports the corresponding pressing member 10 so as to be capable of relative movement in the vertical direction. doing. Therefore, the plurality (four bodies) of the pressing members 10 can be independently moved relative to each other in the vertical direction by the plurality (four bodies) of the guide members 20. Here, the front and rear and left and right holding members 10 and the guide member 20 have the same structure, the rear guide member 20 is not shown in FIG. 1, and the front holding member 10 and the guide member 20 are shown in FIG. Is not shown.

The pressing member 10 includes a shaft-shaped portion 11 that extends in the vertical direction, and a contact body 12 that is attached to the lower end of the shaft-shaped portion 11 and forms a portion that contacts the article W. The contact body 12 is formed in a substantially spherical shape, and the lower end of the shaft-shaped portion 11 is inserted into the inside from the upper end side to be connected. In the contact body 12, when contacting the article W, the spherical surface comes into contact in a substantially point shape. The contact body 12 is not particularly limited, but is formed of an elastically deformable material such as rubber or synthetic resin. If at least the lower half portion of the contact body 12 is formed in a hemispherical shape that bulges downward, the contact body 12 comes into point contact with the article W as described above.

A flange portion 11a having a diameter larger than the outer diameter of the shaft-shaped portion 11 is formed on the upper portion of the shaft-shaped portion 11, and functions as a downward stopper as described later.

FIG. 4A is a partial front sectional view of the holding mechanism according to the embodiment. As shown in FIG. 4A, the guide member 20 is configured by a linear bush into which the shaft-shaped portion 11 of the pressing member 10 is inserted. The guide member 20 is fixed in a state of penetrating a hole formed in the base plate 2. The guide member 20 is supported so that relative movement in the vertical direction with respect to the shaft-shaped portion 11 (pressing member 10) is guided (guided). In addition, the guide member 20 linearly guides the vertical movement of the shaft-like portion 11 and restricts the pressing member 10 from swinging.

The steady rest mechanism 8 further includes a fixing portion 30 provided on each of the four guide members 20. The fixing portion 30 includes a first ring 31 fixed to the upper portion of the guide member 20 and a second ring 32 provided above the first ring 31.

FIG. 5A is a schematic perspective view of the first ring of the fixing portion. FIG. 5B is a schematic perspective view of the second ring of the fixing portion. FIG. 5C is an exploded front sectional view of the fixed portion. FIG. 5D is a front cross-sectional view of the fixed portion. As shown in FIGS. 5A and 5C, the first ring 31 has a hole 31a that vertically penetrates in the central portion thereof, and like the guide member 20, the first ring 31 has an axial portion 11 (see FIG. 4A) of the pressing member 10 therein. ) Is inserted. On the upper part of the hole 31a of the first ring 31, a tapered surface 31b whose opening diameter increases upward is formed.

As shown in FIGS. 5B and 5C, the second ring 32 includes a disk portion 32a having a circular opening at the center and forming a donut shape, and a displacement portion 32b protruding downward from the opening side of the disk portion 32a. ing. A hole 32c is formed at the central tip of the displacing portion 32b, and the shaft-like portion 11 (see FIG. 4A) of the pressing member 10 is inserted into the inside similarly to the guide member 20. The second ring 32 supports the pressing member 10 so as to be relatively movable in the vertical direction by inserting the shaft-shaped portion 11 into the hole 32c, and is configured as a part of the guide member.

The displacement portion 32b is formed in a funnel shape, and is formed so as to come into contact with and fit into the tapered surface 31b of the first ring 31. The displacement portion 32b is formed with a split groove 32d at each predetermined angle in the circumferential direction. Therefore, the displacement portion 32b has a structure in which the displacement portion 32b is divided into a plurality of pieces in the circumferential direction, and the distal ends of the divided portions can be elastically deformed so as to swing and come close to each other.

The displacement portion 32b is pushed inward from the tapered surface 31b as it enters the tapered surface 31b of the first ring 31 (see FIG. 5D). By this pushing, the displacement portion 32b is deformed so as to reduce the diameter of the hole 32c, the axial portion 11 in the hole 32c is radially tightened by the displacement portion 32b, and the vertical relative movement of the axial portion 11 is restricted. It is possible.

Returning to FIG. 4A, the steady rest mechanism 8 further includes a switching unit 40 that switches between a movement restricted state and a movable state of the pressing member 10 by the fixing unit 30. The switching unit 40 includes a support plate 41 extending in a cross shape in the front-rear direction and the left-right direction above the base plate 2, and a single air cylinder (driving source) 42 that supports the support plate 41 from below. ..

A hole through which the shaft-shaped portion 11 of the pressing member 10 is inserted is formed at the front and rear and left and right ends of the support plate 41, and the inner diameter of this hole is set to be smaller than the outer diameter of the flange portion 11a. Therefore, the flange portion 11a is placed on the upper surface of the support plate 41 by being lowered by its own weight without applying an external force to the pressing member 10, and the downward movement of the pressing member 10 including the flange portion 11a is restricted.

The disk portion 32a of the second ring 32 is fixed in surface contact with the lower surface side of the support plate 41 at the position where each hole is formed. Therefore, when the support plate 41 is raised from the state of FIG. 4A as shown in FIG. 4B, the second ring 32 is also raised and separated so as to come out of the first ring 31. The tightening of can be released.

The air cylinder 42 includes a cylinder body 42a fixed to the central portion of the upper surface of the base plate 2, and a rod 42b that moves forward and backward from the upper end of the cylinder body 42a. The upper end of the rod 42b is fixed to the central portion of the lower surface of the support plate 41, and the support plate 41 and the second ring 32 can be moved in the vertical direction by vertically driving the rod 42b.

FIG. 6 is an explanatory diagram of compressed air control of the holding mechanism in the embodiment. As shown in FIG. 6, in the air cylinder 42 of the holding mechanism 1, compressed air (positive pressure air) is supplied from the compressed air supply source 50 via the electromagnetic valve 51. The solenoid valve 51 is provided so that the supply destination of the compressed air can be switched between the first supply passage 53 and the second supply passage 54. In the solenoid valve 51, when the compressed air is supplied to the first supply path 53, the rod 42b (see FIG. 4A) of the air cylinder 42 is driven downward, and the compressed air is supplied to the second supply path 54. Then, the rod 42b of the air cylinder 42 is driven upward.

Further, in the holding mechanism 1, the suction unit 3 sucks air from the compressed air supply source 50 via the ejector 55, and a negative pressure is generated in the suction unit 3 by the suction. A vacuum switch 56 is provided between the ejector 55 and the suction unit 3. The vacuum switch 56 detects whether or not the article W is adsorbed by the adsorption section 3 according to the air pressure. The vacuum switch 56 is connected to the solenoid valve 51.

When the vacuum switch 56 detects the suction of the article W in the suction portion 3, the solenoid valve 51 supplies the compressed air to the first supply path 53, and the rod 42b of the air cylinder 42 descends. With this lowering, the second ring 32 of the fixed portion 30 is also displaced in the lowering direction and fits into the first ring 31, and the movement of the pressing member 10 is restricted by tightening the shaft-shaped portion 11 with the second ring 32 (movement). Regulation status). On the other hand, when the vacuum switch 56 detects that the suction unit 3 does not suck the article W, the solenoid valve 51 supplies the compressed air to the second supply path 54, and the rod 42b of the air cylinder 42 rises. By this rise, the second ring 32 of the fixed portion 30 is also displaced in the upward direction and the fitting with the first ring 31 is released, and the shaft-shaped portion 11 is no longer tightened by the second ring 32, and is pressed by the fixed portion 30. The movement restriction of the member 10 is released (movable state).

Next, an operation when the holding mechanism 1 of the present embodiment holds an article and a transportation method using the holding mechanism 1 will be described with reference to FIGS. 2, 4, and 7 to 12. 7 and 8 are explanatory diagrams of the adsorption process, and FIGS. 9 to 12 are explanatory diagrams of the transfer process.

In the carrying method according to the present embodiment, first, the adsorption process is performed. As shown in FIG. 7, before the suction process is performed, the support plate 41 of the switching unit 40 is raised so that the second ring 32 of the fixed unit 30 is not fitted to the first ring 31. Therefore, the fixing portion 30 does not restrict the vertical movement of the pressing member 10, but the flange portion 11a is placed on the upper surface of the support plate 41 and the downward movement of the pressing member 10 is restricted. At this time, the contact body 12 of the pressing member 10 is arranged below the suction pad 3 a of the suction unit 3.

In the suction step, the coordinate values in the front-rear direction and the left-right direction of the article W placed in the case C1 of the transport source are acquired in advance by image recognition or the like, and are held by a robot arm or the like (not shown) based on the coordinate values. The mechanism 1 is moved above the article W and then positioned. By this positioning, the suction portion 3 is arranged at a position separated upward from the central region of the upper surface of the article W. After that, the entire holding mechanism 1 is lowered by the robot arm or the like. The contact body 12 of the pressing member 10 is placed in contact with the upper surface of the article W at an intermediate stage of the descending. Even if the holding mechanism 1 further descends after this contact, the shaft-shaped portion 11 is slid and guided by the guide member 20, and the pressing member 10 does not descend and is placed on the article W. The weight of 10 acts on the article W. The weight of the pressing member 10 serves as a pressing force for pressing the article W downward.

Then, as shown in FIG. 8, when the suction pad 3a of the suction portion 3 descends to a height position where it contacts the upper surface of the article W, the descending is stopped. When the suction pad 3a comes into contact with the upper surface of the article W, a negative pressure is generated in the suction pad 3a of the suction section 3 and the upper surface of the article W is suction-held. Even when the article W is adsorbed and held by the adsorption section 3, the contact body 12 of the pressing member 10 is in contact with the upper surface of the article W, and the article W is pressed by the own weight of the pressing member 10.

After the article W is suction-held, or substantially at the same time as the suction-holding, the air cylinder 42 is driven as shown in FIG. 4A. By this driving, the rod 42b is lowered, and in response to this lowering, the support plate 41 and the second rings 32 in all the front and rear and left and right four fixing portions 30 are also lowered. Then, the second ring 32 is fitted into the first ring 31 at all four positions, the displacement portion 32b of the second ring 32 is deformed, and the shaft-like portion 11 is tightened from the radial direction, and the pressing members 10 of all four bodies are attached. Restriction of relative movement in the vertical direction is implemented at the same time.

After the suction step is performed, the transfer step of moving the holding mechanism 1 to transfer the article W by driving the robot arm is performed. In the transfer process, first, the holding mechanism 1 is raised as shown in FIG. Then, the article W is moved to a position where the article W is taken out above the case C1 which is the transport source. Next, toward the case C2 (see FIG. 11) which is the destination (sorting destination), the holding mechanism 1 is moved horizontally as shown in FIG. During this horizontal movement, the inertia of the article W causes the article W to swing in the direction of arrow R. However, since the pressing member 10 is in a state in which the pressing force is applied at four positions on the upper surface of the article W adsorbed by the adsorbing portion 3 in the front, rear, left, and right positions, the shake of the article W in the direction of the arrow R due to the horizontal movement is caused. Regulated.

In the present embodiment, as shown in FIG. 11, the destination of the article W in the transfer process is the case C2, and the case C2 is horizontally specified within the movable range of the robot arm from the source case C1. It is considered to be far away. The holding mechanism 1 and the article W held by the holding mechanism 1 are horizontally moved to and positioned above the case C2 by a robot arm or the like. Then, the holding mechanism 1 is lowered by a robot arm or the like, and the article W held by the holding mechanism 1 is placed on the bottom of the case C2 as shown in FIG.

Next, the negative pressure supply to the suction pad 3a is released, and the suction holding of the article W is released. The air cylinder 42 is driven after the suction holding is released or substantially at the same time as the suction holding is released. By this drive, the rod 42b is raised, and in response to this rise, the support plate 41 and the second rings 32 at the front, rear, and left and right four fixed portions 30 are also raised. Then, the second rings 32 come out of the first rings 31 at all of the four positions, the fitting thereof is released, and the tightening of the shaft-shaped portion 11 by the second rings 32 is stopped. The vertical relative movement restriction is released at the same time.

As described above, in the present embodiment, the holding member 10 can be brought into contact with the article W when adsorbing the article W, and in this state, the holding member 10 is held by the fixing portion 30 via the switching portion 40. It is possible to regulate the movement and maintain the state in which the pressing member 10 is in contact with the article W. Thereby, the mechanism for driving the pressing member 10 up and down can be omitted, and the pressing member 10 can be fixed to the position in contact with the upper surface of the article W without detecting the position of the article W, and the detection means such as a sensor is also omitted. Thus, the structure can be simplified. Moreover, since the article W is not detected by the sensor or the like, it is possible to eliminate the detection time and the time for correcting the position of the pressing member 10 based on the detection result. As a result, it is possible to shorten the time for moving the pressing member 10 in order to regulate the shake by the steady rest mechanism 8, and consequently to shorten the time for carrying the article W.

Further, since the plurality of pressing members 10 are provided with the guide members 20 and the plurality of pressing members 10 independently move up and down, the pressing members 10 can be easily arranged at arbitrary vertical positions and the article W Can be contacted with. As a result, even if all or part of the height position of the top surface of the article W is changed, all the pressing members 10 can be moved to the article W without electrical control according to the top surface shape and height of the article W. The height can be set so as to be in contact with, which also simplifies the configuration.

Further, by driving the single air cylinder 42, the movement of the pressing member 10 in all the four fixing portions 30 can be restricted and released, and when the driving source is installed in each of the pressing members 10 at the four positions. In comparison, the structure can be simplified and the weight can be reduced.

Further, the embodiments of the present invention are not limited to the above-mentioned embodiments, and may be variously changed, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of the technology or another derivative technology, the method may be implemented. Therefore, the claims cover all embodiments that may be included in the scope of the technical idea of the present invention.

In the above-described embodiment, the article W to be held is a lunch box, but the article W is not limited as long as it can be suction-held by the holding mechanism 1. For example, other foods such as sandwiches, breads, and bentos, various electric devices and devices, and parts thereof, or those packed in boxes or trays other than lunch boxes may be used. Further, the position where the pressing member 10 presses the article W is not limited to the above-described collar portion Wc, and may be the inclined side surface or the top surface of the lid portion Wb.

Further, the shape of the contact body 12 of the pressing member 10 may be an inclined surface or a horizontal surface depending on the contact position with the article W. However, by making the lower half part a spherical surface, it is advantageous in that substantially point contact can be made even if the orientation of the contact position of the article W changes.

Further, the guide member 20 may have a configuration other than the linear bush as long as it can support the pressing member 10 as in the above.

Further, the fixing portion 30 may be changed to another structure having an appropriate engaging structure capable of restricting the movement of the pressing member 10.

Further, the drive source in the switching unit 40 is the air cylinder 42, but as long as the second ring 32 of the fixed unit 30 can be moved up and down, the configuration may be changed to a direct drive motor or the like.

Further, the number and locations of the pressing member 10, the guide member 20, and the fixed portion 30 are not limited to the four positions in the front and rear and the left and right, and may be different depending on the shape of the article W, the suction position of the suction portion 3, and the like. The number of installations may be increased or decreased, or the installation location may be changed.

DESCRIPTION OF SYMBOLS 1 Holding mechanism 3 Adsorption part 8 Steady stop mechanism 10 Holding member 20 Guide member 30 Fixed part 32 Second ring (guide member)
40 switching unit 42 air cylinder (driving source)
50 compressed air supply source 51 solenoid valve 53 first supply path 54 second supply path 56 vacuum switch W article

Claims (5)

A holding mechanism for sucking and holding an article from the upper surface side,
An adsorption part that adsorbs the upper surface of the article,
When the holding mechanism moves in the horizontal direction, a steadying mechanism that restricts a shake of the article held by the suction unit due to the movement,
The steady rest mechanism is a pressing member that abuts the article adsorbed by the adsorbing section and exerts a pressing force at least by its own weight,
A guide member for supporting the pressing member so as to be relatively movable in the vertical direction,
A fixed portion that restricts the movement of the pressing member by displacing the guide member;
A holding mechanism, comprising: a switching unit that switches between a movement restricted state and a movable state of the pressing member by the fixing unit. The plurality of pressing members are provided, and the switching unit is provided so as to be able to switch between a movement restriction state and a movable state of all the pressing members by driving with a single drive source. Retention mechanism. The holding mechanism according to claim 2, wherein the plurality of pressing members are individually movable in the vertical direction independently in the movable state. The drive source is an air cylinder,
The suction by the suction unit and the driving of the air cylinder are performed through the same compressed air supply source,
A vacuum switch for detecting whether or not an article is adsorbed by the adsorption section, a first supply path and a second supply path for supplying compressed air from the compressed air supply source to the air cylinder, and compression to the air cylinder. An electromagnetic valve that switches between the first supply path and the second supply path as an air supply destination is provided,
When the vacuum switch detects the suction of the article by the suction portion, the supply destination of the compressed air in the solenoid valve is switched to the first supply path, and the fixed portion sets the pressing member in the movement restricting state. By driving the air cylinder in the direction, and detecting that the vacuum switch does not adsorb the article in the adsorption section, the destination of the compressed air in the solenoid valve is switched to the second supply path, The holding mechanism according to claim 2 or 3, wherein a fixing portion drives the air cylinder in a direction in which the pressing member is in a movable state. A holding mechanism according to any one of claims 1 to 4,
And a moving mechanism capable of carrying the suction-held article by moving the holding mechanism in the horizontal direction.

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