Adsorption device

Abstract

To provide a suction device capable of lifting the article while suppressing an excessive load from being placed on an article.SOLUTION: Provided is a suction device 10 including: an upper support mechanism 13 provided with an upper suction pad 11 coming into contact with an upper side of an article W, as well as, with an upper suction unit 12 to which the upper suction pad 11 is attached, and suctioning and holding the upper side of the article W; and a lateral side support mechanism 16 provided with a lateral side suction pad 14 coming into contact with a lateral side of the article W, as well as, a lateral side suction unit 15 to which the lateral side suction pad 14 is attached, and suctioning and holding the lateral side of the article W. The suction device comprises: a lifting body 25, which is lifted from and lowered to a base part 23, integrally with the upper suction unit 12; and control means which brings the lifting body 25, together with the upper suction unit 12, into a state of being lowered to the base part 23 by its own weight, and causes the upper suction unit 12 arranged above the article W to be lowered together with the lifting body 25, and brings the upper side of the article W in a placed state into a state of being suctioned and held by the upper support mechanism 13, and causes the lateral side support mechanism 16 to suction and hold the lateral side of the article W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a suction device for suctioning an article. [Background technology]

[0002] At sites where goods are loaded, unloaded, or transported, suction devices that suck up and lift goods are used to improve work efficiency, reduce the burden on workers, etc. Suction devices include those disclosed in Patent Documents 1 and 2 that suck up only the top side of goods, and those disclosed in Patent Document 3 that suck up the sides of goods in addition to the top side.

[0003] For example, the top of a cardboard box containing PET bottles of beverages has a seam (glued portion) where overlapping pieces of cardboard are glued together with hot melt adhesive. The adhesive strength of the hot melt is adjusted so that a person can easily release the seam and open the top of the cardboard box. Therefore, when lifting the cardboard box, if an attempt is made to lift the cardboard box by suctioning only the top of the box, the seam may come loose. Therefore, a suction device that suctions the top and sides of the cardboard box is effective.

[0004] In general, a suction device that suctions the top and sides of an article moves an upper support mechanism that suctions the top side of the article to a position where it comes into contact with the top side of the article, and then suctions the top side of the article. If the heights of the articles vary from one another, the suction device determines the height position to which the upper support mechanism should move based on the heights of the articles detected by image recognition technology or the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-198542 [Patent Document 2] Japanese Patent Application Publication No. 2020-168700 [Patent Document 3] Japanese Patent Application Publication No. 11-70917 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the detection accuracy of the height of an article is less than a certain level, the suction device cannot accurately position the upper support mechanism at an appropriate height position according to the height of the article. For example, as shown in Fig. 5, when the upper support mechanism 100 is positioned at a height higher than an appropriate height position relative to the article 101 and the suction unit 102 of the upper support mechanism 100 begins suction, the upper side of the article 101 is sucked and lifted by the upper support mechanism 100 before the side support mechanism 103 has sucked the article 101 (i.e., before the side support mechanism 103 has sucked the article 101), causing a problem of excessive load being placed on the upper side of the article 101.

[0007] 5 (and also FIG. 6) shows an example in which a suction pad 105 that contacts the article 101 is attached to the suction unit 102, and the side support mechanism 103 has a suction unit 104 and a suction pad 106 that is attached to the suction unit 104 and contacts the article 101. The suction pads 105 and 106 are formed of an elastic body that is compressed when the suction units 102 and 104 suck the article 101.

[0008] On the other hand, if the upper support mechanism 100 is placed at a position lower than an appropriate height relative to the article 101, as shown in Figure 6, a problem occurs in which the upper support mechanism 100 applies a load to the entire article 101 in a direction that crushes the article 101. In this regard, it is conceivable to solve the above-mentioned problem by adopting a system that can detect the height of an article with a certain level of accuracy or higher, but adopting such a system would lead to other problems, such as a longer time until the height of the article is detected and higher manufacturing costs for the entire suction device. Furthermore, there are limits to the precision with which the shape of each item can be made uniform (for example, to prevent the formation of protrusions on the top of the item) and the manufacturing precision of the equipment (for example, the pallet on which the item is placed), so even if the accuracy in detecting the height of the item is increased to a certain level or higher, the above-mentioned problem of excessive stress being placed on the item will still occur.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a suction device that can lift an object while preventing an excessive load from being applied to the object. [Means for solving the problem]

[0010] The suction device according to the present invention, which is in accordance with the above-mentioned object, comprises an upper support mechanism that includes an upper suction pad that contacts the upper side of an article and an upper suction unit to which the upper suction pad is attached, and that suction-holds the upper side of the article; and a side support mechanism that includes a side suction pad that contacts the side of the article and a side suction unit to which the side suction pad is attached, and that suction-holds the side of the article, and further comprises a lifting body that rises and falls integrally with the upper suction unit relative to a base portion, and the lifting body rises and falls together with the upper suction unit due to the action of an upward force. and a weight-down state in which the lifting body and the upper suction unit are lowered relative to the base by their own weight, and a control means for controlling the upper suction unit, the side suction unit, and the switching means, wherein the control means switches the switching means to the weight-down state, lowers the upper suction unit arranged above the placed article together with the lifting body, and causes the upper side of the placed article to be adsorbed and held by the upper support mechanism, and causes the side support mechanism to adsorb and hold the side of the article. [Effects of the Invention]

[0011] The suction device of the present invention comprises a lifting body that rises and falls together with the upper suction unit relative to the base, a switching means for switching between an elevated state in which the lifting body rises together with the upper suction unit due to the action of an upward force, and a gravity-lowering state in which the lifting body and the upper suction unit descend together with the upper suction unit relative to the base due to their own weight, and a control means for controlling the upper suction unit, the side suction unit, and the switching means. The control means switches the switching means to the gravity-lowering state, causing the upper suction unit arranged above an item in a placed state to descend together with the lifting body, causing the upper side of the placed item to be adsorbed and held by the upper support mechanism, and causing the side support mechanism to adsorb and hold the sides of the item. Therefore, it is possible to stably lower the upper suction unit from a state where it is positioned higher than the position where the upper support mechanism would crush the item, and to avoid the upper side of the item being adsorbed and held by the upper support mechanism when it has lifted the item before adsorbing and holding the sides of the item. As a result, it is possible to lift items while preventing excessive load from being placed on the item. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an explanatory diagram of a suction device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram showing the connection of a control means. [Figure 3] 10A and 10B are explanatory views each illustrating a process in which the suction device lifts up an article placed on a placement surface. [Figure 4] 10A and 10B are explanatory views each illustrating a process in which the suction device lifts up an article placed on a placement surface. [Figure 5] FIG. 10 is an explanatory diagram showing how a suction device according to a conventional example applies a load to an article. [Figure 6] FIG. 10 is an explanatory diagram showing how a suction device according to a conventional example applies a load to an article. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, embodiments of the present invention will be described with reference to the accompanying drawings to facilitate understanding of the present invention. 1, a suction device 10 according to one embodiment of the present invention has an upper support mechanism 13 that includes upper suction pads 11 that come into contact with the upper side of an article W and upper suction units 12 to which the upper suction pads 11 are attached, and that suction-holds the upper side of the article W, and a side support mechanism 16 that includes side suction pads 14 that come into contact with the sides of the article W and side suction units 15 to which the side suction pads 14 are attached, and that suction-holds the sides of the article W. These will be described in detail below.

[0014] As shown in Figure 1, the item W in this embodiment is a roughly rectangular cardboard box containing a PET bottle containing a beverage, and on the upper side (the upper surface in this embodiment) there is a seam (adhesive joint) formed by bonding overlapping pieces of cardboard with hot melt H. The upper suction pad 11 and the upper suction unit 12 provided in the upper support mechanism 13 are both rectangular (including square) shapes of the same size in a plan view, and the upper suction pad 11 is adhered with an adhesive to the lower end of the upper suction unit 12. A hole (not shown) is formed in the upper suction unit 12, and the upper suction unit 12 can take in air into the hole from the lower end.

[0015] 2, the upper suction unit 12 is connected to an air compressor 19 via a solenoid valve 17 and a regulator 18, and the solenoid valve 17 and the air compressor 19 are connected to a control means 20 that can be configured by an electronic circuit or the like. The control means 20 can send command signals to the solenoid valve 17 and the air compressor 19 to control them. In the following description, unless otherwise specified, it is assumed that the air compressor 19 is operating (is in a state where it can send compressed air to the solenoid valve 17, etc.).

[0016] When the control means 20 sets the solenoid valve 17 to a state in which compressed air sent from the air compressor 19 is supplied to the upper suction unit 12, negative pressure is created inside the hole formed in the upper suction unit 12, causing the upper suction unit 12 to suck in air from the lower end. On the other hand, when the control means 20 sets the solenoid valve 17 to a state in which compressed air from the air compressor 19 is not sent to the upper suction unit 12, the upper suction unit 12 stops sucking in air. Thus, the control means 20 indirectly controls the upper suction unit 12 (switches the state of the upper suction unit 12) by controlling the solenoid valve 17 and the air compressor 19.

[0017] The upper suction pad 11 is made of an elastic body, and has a plurality of through holes (not shown) formed vertically through the upper suction pad 11. Therefore, when the upper suction unit 12 starts to suck in air from the lower end, the air below the upper suction pad 11 is sucked into the upper suction unit 12 via the plurality of through holes formed in the upper suction pad 11.

[0018] 1, an air cylinder 26 is provided above the upper suction unit 12. The air cylinder 26 has a cylinder tube 23, which is an example of a base portion connected to the robot arm 22, a piston 24 that moves up and down within the cylinder tube 23, and a rod 25, which is an example of an elevator body, arranged vertically and whose upper end is connected to the piston 24. A connecting member 27, to which the upper suction unit 12 is fixed, is attached to the lower end of the rod 25 that protrudes downward from the cylinder tube 23.

[0019] 2, the cylinder tube 23, whose axis is disposed vertically, is connected to the air compressor 19 via a solenoid valve 29 and a regulator 30, which are examples of switching means, each connected to the control means 20. The control means 20 controls the solenoid valve 29 so that compressed air from the air compressor 19 is supplied to an area below the piston 24 in the cylinder tube 23 (hereinafter referred to as the "lower area"), so that the inside of the cylinder tube 23 is open to the atmosphere, or so that air does not flow in or out of the cylinder tube 23.

[0020] When the solenoid valve 29 is in a state where it sends compressed air to the lower region inside the cylinder tube 23, an upward force acts on the piston 24, causing the rod 25 to rise together with the upper suction unit 12, the connecting member 27, and the piston 24 relative to the cylinder tube 23. This state of the solenoid valve 29 is called the "rising state." When the solenoid valve 29 is in the rising state, an upward force acts on the rod 25 via the piston 24 (i.e., the rod 25 is acted on by the upward force and rises together with the upper suction unit 12).

[0021] Furthermore, when the solenoid valve 29 is in a state in which the inside of the cylinder tube 23 is open to the atmosphere, the rod 25, together with the upper suction unit 12, the connecting member 27, and the piston 24, descends relative to the cylinder tube 23 due to the weight of the rod 25, the upper suction unit 12, the connecting member 27, the piston 24, etc. The state of the solenoid valve 29 in this state is called a "gravity descending state." Therefore, the solenoid valve 29 is switched between the ascending state and the gravity descending state by the control means 20.

[0022] Then, with the rod 25 and piston 24 positioned at the upper limit position relative to the cylinder tube 23, the solenoid valve 29 is set in a state where it sends compressed air to the lower region within the cylinder tube 23, and the rod 25 is fixed to the cylinder tube 23 together with the upper suction unit 12, the connecting member 27 and the piston 24. Furthermore, a pressure sensor 28 that measures the pressure inside the cylinder tube 23 is connected to the control means 20 .

[0023] When the upper suction unit 12 moves up and down with the lower end of the upper suction pad 11 not in contact with the article W, the upper suction pad 11 moves up and down together with the upper suction unit 12 without deforming. On the other hand, when the upper suction unit 12 moves down with the lower end of the upper suction pad 11 in contact with the article W, the upper suction pad 11 deforms and is compressed in the vertical direction. The upper suction pad 11, whose lower end has come into contact with the article W and been compressed in the vertical direction, returns to its original state as the upper suction unit 12 moves up.

[0024] It is also possible to use an upper suction pad that does not substantially elastically deform instead of the upper suction pad 11. Such an upper suction pad always rises and falls together with the upper suction unit 12. It goes without saying that when the lower end of the upper suction pad is in contact with the upper side of the article W, neither the upper suction unit 12 nor the upper suction pad can fall, even if the upper suction unit 12 and the like are able to rise and fall relative to the cylinder tube 23.

[0025] 1, a cylinder tube 33 of an air cylinder 32 having a rod 31 arranged horizontally is fixed to the connecting member 27. A piston 34 connected to one end of the rod 31 is provided inside the cylinder tube 33, whose axis is arranged horizontally. The upper side of a vertically long arm 35 is fixed to the other end of the rod 31 protruding from the cylinder tube 33, and the side suction unit 15 is attached to the lower side of the arm 35.

[0026] The side suction unit 15 and the side suction pad 14 of the side support mechanism 16 are both rectangular (including square) and of the same size when viewed from the side. The side suction pad 14 is adhered with an adhesive to one horizontal side of the side suction unit 15 (the side opposite to the side attached to the arm 35). The side suction unit 15 has a hole (not shown) that opens to one horizontal end.

[0027] 2, the side suction unit 15 is connected to the air compressor 19 via a solenoid valve 36 and a regulator 18, which are connected to the control means 20. The control means 20 can control the solenoid valve 36 by sending a command signal to the solenoid valve 36. When the control means 20 sets the solenoid valve 36 to a state in which compressed air sent from the air compressor 19 is supplied to the side suction unit 15, negative pressure is created inside the hole opening at one horizontal end of the side suction unit 15, and the side suction unit 15 sucks air from the one horizontal end.

[0028] On the other hand, the control means 20 sets the solenoid valve 36 to a state in which compressed air from the air compressor 19 is not sent to the side suction unit 15, so that the side suction unit 15 does not suck in air. Thus, the control means 20 indirectly controls the side suction unit 15 (switches the state of the side suction unit 15) by controlling the solenoid valve 36 and the air compressor 19.

[0029] The side suction pads 14 are made of an elastic body, and have a plurality of through holes (not shown) that pass horizontally through the side suction pads 14. Therefore, when the side suction units 15 are in a state of sucking air from one horizontal side end, the air around one horizontal side of the side suction pads 14 is sucked into the side suction units 15 through the plurality of through holes formed in the side suction pads 14.

[0030] 2, the cylinder tube 33 is connected to the air compressor 19 via a solenoid valve 37 and a regulator 30, which are connected to the control means 20. The control means 20 controls the solenoid valve 37 so that compressed air from the air compressor 19 is supplied to either an area on one horizontal side of the piston 34 in the cylinder tube 33 (hereinafter referred to as the "first area") or an area on the other horizontal side of the cylinder tube 33 (hereinafter referred to as the "second area"), so that either or both of the first area and the second area in the cylinder tube 33 are open to the atmosphere, or so that air does not flow in or out of the cylinder tube 33.

[0031] The side suction unit 15, piston 34, and rod 31 move together in the horizontal direction to the other side (in the direction in which the length of the rod 31 protruding from the cylinder tube 33 increases) relative to the cylinder tube 33 when compressed air is sent to the first region in the cylinder tube 33 and the second region is opened to the atmosphere. Also, the side suction unit 15, piston 34, and rod 31 move together in the horizontal direction to one side (in the direction in which the length of the rod 31 protruding from the cylinder tube 33 decreases) relative to the cylinder tube 33 when the first region in the cylinder tube 33 is opened to the atmosphere and compressed air is sent to the second region.

[0032] By preventing air from flowing in or out of the cylinder tube 33, the lateral suction unit 15, the piston 34, and the rod 31 are fixed to the cylinder tube 33. A pressure sensor 28a that measures the pressure inside the cylinder tube 33 is connected to the control means 20.

[0033] When the side suction unit 15 moves horizontally to one side relative to the cylinder tube 33 while one horizontal end of the side suction pad 14 is not in contact with the article W, the side suction pad 14 moves horizontally to one side relative to the cylinder tube 33 together with the side suction unit 15 without deforming. On the other hand, when the side suction unit 15 moves horizontally to one side relative to the cylinder tube 33 while one horizontal end of the side suction pad 14 is in contact with the article W, the side suction pad 14 deforms and is compressed horizontally. Then, the side suction pad 14, which has been compressed horizontally as one horizontal end thereof comes into contact with the article W, returns to its original state as the side suction unit 15 moves horizontally to the other side relative to the cylinder tube 33. Note that a side suction pad that does not substantially elastically deform may be used instead of the side suction pad 14.

[0034] In addition, the control means 20 is connected to a pressure sensor 38 that detects the pressure inside the hole opening at the lower end of the upper suction unit 12, a pressure sensor 39 that detects the pressure inside the hole opening at one horizontal side end of the side suction unit 15, and an image analysis means 41 that detects the position of the item W based on an image captured by the imaging means 40 of the item W.

[0035] Next, a process of lifting the article W placed on the placement surface G using the suction device 10 will be described.

[0036] <Process 1> The image analysis means 41 detects the overall position of the item W, the height position of the upper side of the item W, and the lateral position of the item W supported by the lateral support mechanism 16 based on the captured image of the item W placed on the loading surface G captured by the imaging means 40.

[0037] <Process 2> The control means 20 acquires various positional information of the article W from the image analysis means 41, and operates the robot arm 22 based on this information to move the air cylinders 26, 32, the upper support mechanism 13, the side support mechanism 16, etc., so that the upper suction unit 12 is positioned at a predetermined position directly above the article W placed on the placement surface G, as shown in Figure 3(A), and then stops the robot arm 22. The predetermined position directly above the article W means the position of the upper suction unit 12 where the air cylinder 26 can increase the protruding length of the rod 25 from the cylinder tube 23 to lower the upper suction unit 12, and the air cylinder 32 can decrease the protruding length of the rod 31 from the cylinder tube 33 to move the side suction unit 15 to one side in the horizontal direction.

[0038] Furthermore, when the upper suction unit 12 is positioned at a predetermined position directly above the item W, the upper suction pad 11 may or may not be in contact with the upper side of the item W, but the upper suction unit 12 must be positioned within a height range that does not apply excessive load (for example, a load that would crush the item W) to the top of the item W through the upper suction pad 11, and that allows the upper support mechanism 13 to suction and hold the upper side of the item W without lifting it from the loading surface G by increasing the protruding length of the rod 25 from the cylinder tube 23.

[0039] Furthermore, when the upper suction unit 12 is positioned at a predetermined position directly above the article W, the side suction pads 14 must be positioned so that they do not come into contact with the sides of the article W, and the length of the rod 31 protruding from the cylinder tube 33 must be shortened so that the side support mechanism 16 can suction and hold the sides of the article W.

[0040] <Process 3> Next, the control means 20 controls the solenoid valve 29 (i.e., the switching means) to open the inside of the cylinder tube 23 to the atmosphere, i.e., to place the solenoid valve 29 in a state of descending under its own weight, and lowers the upper suction unit 12 arranged above the item W placed on the loading surface G together with the rod 25, etc., so that the upper side of the item W placed on the loading surface G is adsorbed and held by the upper support mechanism 13.

[0041] Here, the amount of air released per unit time from the lower region inside the cylinder tube 23 is adjusted (limited) by a flow control valve (one example of a resistance force applying means that applies resistance force to the descent of the lifting body) not shown that corresponds to the cylinder tube 23. The descent speed of the upper suction unit 12, the rod 25, etc. is adjusted by adjusting (limiting) the amount of air released per unit time. In step 3 and step 4 described below, the cylinder tube 23 is kept fixed by the robot arm 22. Therefore, the control means 20 sets the solenoid valve 29 to a gravity descent state with the cylinder tube 23 fixed.

[0042] In this embodiment, when the upper suction unit 12 is lowered together with the rod 25, etc., the control means 20 controls the solenoid valve 17 to put the upper suction unit 12 into a suction state, so that the suction of air from the lower end of the upper suction pad 11 by the suction of the upper suction unit 12 (i.e., the suction of the upper suction unit 12) contributes to the descent of the upper suction unit 12 and the rod 25, etc. (the suction force of the upper suction unit 12 contributes to the force that lowers the upper suction unit 12 and the rod 25, etc.).

[0043] Therefore, until the upper support mechanism 13 adsorbs and holds the upper side of the item W placed on the loading surface G, the rod 25 and the upper suction unit 12, etc. will descend due to the weight of the rod 25, the upper suction unit 12, the upper suction pad 11, etc., and the suction force of the upper suction unit 12. As shown in Figure 3(B), the upper suction unit 12 and rod 25, etc. descend and stop until the upper suction pad 11 is sandwiched between the upper suction unit 12 and the item W and compressed vertically, and the upper support mechanism 13 is in a state of suction-holding the item W.

[0044] The control means 20 detects that the measurement value of the pressure sensor 38 has reached a predetermined value or greater, and thereby detects that the upper support mechanism 13 has sucked and held the upper side of the article W. In this embodiment, the state in which the upper support mechanism 13 has sucked and held the upper side of the article W means a state in which the measurement value of the pressure sensor 38 has reached a predetermined value or greater (a state in which the upper support mechanism 13 is sucking and holding the upper side of the article W with a force greater than or equal to a predetermined magnitude).

[0045] Here, if an upper suction pad that does not substantially elastically deform is used instead of the upper suction pad 11, when the robot arm 22 stops in step 2, the upper suction pad is positioned at a height that is a certain distance from the upper side of the article W, and when the upper suction unit 12 is lowered together with the rod 25, etc. in step 3, the rod 25 and the upper suction unit 12 are lowered by the weight of the rod 25, the upper suction unit 12, etc., so there is no need to put the upper suction unit 12 into a suction state. However, if the upper suction unit 12 is lowered together with the rod 25, etc. without being put into a suction state, in order to have the upper support mechanism suction and hold the article W, the upper suction unit 12 needs to be sucked with the upper suction pad in contact with the upper side of the article W.

[0046] <Step 4> Next, the control means 20 controls the solenoid valve 37 to send compressed air to the other end of the cylinder tube 33, thereby moving the rod 31 together with the side support mechanism 16 and the arm 35 horizontally to one side relative to the cylinder tube 33, and bringing the side suction pad 14 into contact with the side of the article W, as shown in Figure 4(A) . In this embodiment, when moving the rod 31, the side support mechanism 16, etc. to one side in the horizontal direction, the control means 20 controls the solenoid valve 36 to put the side suction unit 15 into a suction state, so that the suction of air from one horizontal side of the side suction pad 14 by the suction of the side suction unit 15 also contributes to the movement of the rod 31, the side support mechanism 16, etc. to one side in the horizontal direction.

[0047] The rod 31 and the side support mechanism 16, etc., move horizontally to one side and stop until the side suction pad 14 is sandwiched between the side suction unit 15 and the article W and compressed and deformed in the horizontal direction, and the side support mechanism 16 is in a state of suction-holding the article W. Therefore, in this embodiment, the control means 20 causes the upper support mechanism 13 to suction-hold the upper side of the article W, and causes the side suction unit 15 to start suction, causing the side support mechanism 16 to suction-hold the side of the article W.

[0048] The state in which the side support mechanism 16 suction-holds the article W refers to a state in which the measurement value of the pressure sensor 39 is equal to or greater than a preset value (a state in which the side support mechanism 16 suction-holds the article W with a force equal to or greater than a predetermined force). The control means 20 detects that the measurement value of the pressure sensor 39 is equal to or greater than the predetermined value, thereby detecting that the side support mechanism 16 has suction-held the side of the article W, and controls the solenoid valve 37 to prevent air from being released from the cylinder tube 33, thereby fixing the rod 31 to the cylinder tube 33. Furthermore, if side suction pads that do not substantially elastically deform are used instead of the side suction pads 14, the side support mechanism suction-holds the side of the article W without the side suction pads deforming.

[0049] <Process 5> With the upper support mechanism 13 suction-holding the upper side of the article W and the side support mechanism 16 suction-holding the side of the article W, the control means 20 controls the solenoid valve 29 to send compressed air to the lower region of the cylinder tube 23, as shown in Figure 4(B), i.e., sets the solenoid valve 29 to an up state, raising the rod 25 relative to the cylinder tube 23, and also controls the robot arm 22 to operate the robot arm 22 to raise the cylinder tube 23, thereby lifting the article W from the loading surface G.

[0050] By going through the above-mentioned steps 1 to 5, it is possible to reliably prevent the upper support mechanism 13 from applying excessive load to the item W in a direction that would crush the item W, or from lifting the item W while the upper support mechanism 13 is suction-holding the item W alone, and as a result, it is possible to lift the item W while preventing excessive load from being applied to the entire item W.

[0051] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all changes in conditions that do not depart from the gist of the present invention are within the scope of application of the present invention. For example, it goes without saying that the object to be sucked and held by the suction device is not limited to a cardboard box containing a plastic drink bottle, and the object may have any shape that can be sucked by the upper support mechanism and the side support mechanism, such as a triangular prism or a cylinder.

[0052] Furthermore, it is not necessary to employ an air cylinder with a lifting body. Instead of an air cylinder, for example, an electric cylinder with a rod as the lifting body, or a mechanism with a rack as the lifting body and a pinion that meshes with the rack, can be employed. However, when an electric cylinder is employed, the time required from when the upper support mechanism suctions and holds the upper side of the article to when that state is detected becomes longer than when an air cylinder is employed. Furthermore, when a mechanism with a rack and pinion is employed, it is necessary to neutralize the pinion so that the rack can be raised and lowered, making the design more complex than when an air cylinder is employed.

[0053] The side support mechanism does not have to be raised and lowered integrally with the lifting body and the upper suction unit, in which case a mechanism for raising and lowering only the side support mechanism may be provided. Furthermore, the position of the article does not have to be detected by an imaging means and an image analysis means, and the position of the article may be detected using, for example, a laser distance meter or a photoelectric sensor. [Explanation of symbols]

[0054] 10: suction device, 11: upper suction pad, 12: upper suction unit, 13: upper support mechanism, 14: side suction pad, 15: side suction unit, 16: side support mechanism, 17: solenoid valve, 18: regulator, 19: air compressor, 20: control means, 22: robot arm, 23: cylinder tube, 24: piston, 25: rod, 26: air cylinder, 27: connecting member, 28, 28a: pressure sensor, 29: solenoid valve, 30: regulator, 31: rod, 32: air cylinder, 33: cylinder tube, 34: piston, 35: arm, 36, 37: solenoid valve, 38, 39: pressure sensor, 40: imaging means, 41: image analysis means, G: placement surface, H: hot melt, W: article

Claims

1. a suction device having an upper support mechanism that includes an upper suction pad that contacts the upper side of an article and an upper suction unit to which the upper suction pad is attached, and that suction-holds the upper side of the article; and a side support mechanism that includes a side suction pad that contacts the side of the article and a side suction unit to which the side suction pad is attached, and that suction-holds the side of the article, a lifting body that moves up and down integrally with the upper suction unit relative to a base portion; a switching means for switching between an ascending state in which the ascending / descending body is acted upon by an upward force and ascends together with the upper suction unit, and a gravity descending state in which the ascending / descending body and the upper suction unit descend by their own weight relative to the base portion; a control unit for controlling the upper suction unit, the side suction unit, and the switching unit, The control means sets the switching means to the gravity descending state, causing the upper suction unit arranged above the placed item to descend under its own weight together with the lifting body, causing the upper side of the placed item to be adsorbed and held by the upper support mechanism, and causing the side support mechanism to adsorb and hold the sides of the item, and further, when the control means sets the switching means to the gravity descending state to cause the upper suction unit and the lifting body to descend under their own weight, it sets the upper suction unit to a suction state and causes air to be sucked into the upper suction pad.

2. 2. The suction device according to claim 1, wherein the upper suction pad is formed of an elastic material and is compressed between the upper suction unit and the article while the upper support mechanism is suction-holding the upper side of the article.

3. 3. The suction device according to claim 1, further comprising an air cylinder having a cylinder tube as said lifting body and said base portion.

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