Suction pad and suction hand

Abstract

Provided is a suction pad for suctioning an object, the suction pad comprising: a first pad; a second pad that has an outer shape larger than that of the first pad and covers the outside of the first pad; and a valve that opens more as the flow rate of a passing fluid decreases and closes more as the flow rate increases. A first space, which is inside the first pad, is connected to a third space without passing through the valve, said third space being connected to a vacuum path. A second space, which is inside the second pad and outside the first pad, is connected to the third space through the valve.

Description

Suction pad and suction hand

[0001] The present invention relates to a suction pad and a suction hand.

[0002] A suction cup for sucking and conveying articles is known, which is characterized by comprising a small suction cup fixed to the bottom end of an intake pipe with an opening, and a large suction cup fixed to the bottom end of the intake pipe around the small suction cup and with an opening concentric with the small suction cup, surrounding the small suction cup (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2003-225880

[0004] The present disclosure provides a suction pad and a suction hand that can suction objects of different sizes.

[0005] One aspect of the present disclosure is an adsorption pad for adsorbing an object, comprising: a first pad; a second pad having an outer shape larger than the first pad and covering the outside of the first pad; and a valve that opens as the flow rate of a fluid passing through decreases and closes as the flow rate increases, wherein the first space, which is the space inside the first pad, is connected to a third space connected to a vacuum path without going through the valve, and the second space, which is the space inside the second pad and outside the first pad, is connected to the third space via the valve.

[0006] One aspect of the present disclosure is an adsorption hand that adsorbs an object, comprising: an imaging device that images the object; the above-mentioned adsorption pad; and a rotation mechanism that rotates the adsorption pad within a plane along the central axis of the adsorption pad.

[0007] According to the present disclosure, objects of different sizes can be adsorbed.

[0008] 12 is a perspective view of an external appearance of a robot device equipped with a suction hand according to a first embodiment of the present disclosure; a side view of a suction pad; a perspective view of a first stay to which a second pad is connected; a side view of a bellows tube in the suction pad with a cut; a perspective view of the first stay from above (the third space side); a side view of the first stay to which the first pad is attached; an explanatory diagram showing a vacuum path of the suction pad; a side view of the suction pad with an object sucked by the first pad; a side view of the suction pad with an object sucked by the first pad and the second pad, together with a perspective view of the main part; an explanatory diagram showing the correlation between the pressure of the suction pad applied to the object and the retreat stroke caused by the reaction force; an explanatory diagram showing dimensional changes of each part of the suction pad from an unloaded state to a full stroke; a front view of an example of a suction hand equipped with an imaging device and a rotation mechanism; a plan view of FIG. 12; an explanatory diagram of operation showing the tilt rotation state of the suction pad; a side view showing a schematic configuration of the suction pad according to a second embodiment of the present disclosure;

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Background to the development of the embodiment of the present disclosure) The suction cup for suction and conveyance described in Patent Document 1 takes into consideration that the small and large suction cups complement each other to maintain suction power. However, it does not take into consideration holding objects such as boxes, bags, or objects of unknown size. Furthermore, conventionally, multiple suction pads are attached to the tip of a suction hand, and the suction pads are switched by switching the tip of the suction hand using a tool changer. In this case, it is difficult to pick up the object without recognizing information about the object to be picked up (particularly the size of the suction surface of the object).

[0011] Therefore, in the following embodiments, we will describe suction pads and suction hands that can use multiple suction pads without switching using a tool changer or the like, and that can suction objects without having to recognize information about the object to be suctioned before suction.

[0012] 1 is an external perspective view of a robot device 13 equipped with a suction hand 11 according to a first embodiment of the present disclosure. In the diagrams with arrows indicating directions, the X axis indicates the front-to-rear direction, the Y axis indicates the left-to-right direction, and the Z axis indicates the up-to-down direction. The X axis and Y axis are orthogonal to each other and are included in a horizontal plane. The Z axis is included in a longitudinal plane.

[0013] The suction hand 11 can be suitably used in a robot device 13. An automatic guided vehicle (AGV) for transporting cargo (e.g., an object 27), a bin, etc. can freely enter and exit the robot device 13, and a platform for the AGV, etc., serves as a stage 25 for sorting.

[0014] The robot device 13 may be an automated machine capable of picking and placing, such as a manipulator (arm robot). In this case, the manipulator has a base installed in a sorting area for luggage (e.g., object 27), a production line, or the like. The manipulator may be configured, for example, with a rotating unit attached to the top of the base and rotating horizontally, an upper arm attached to the rotating unit and swinging back and forth, a forearm attached to the upper arm and swinging up and down, and a wrist with three degrees of freedom attached to the forearm.

[0015] A pair of columns 31, spaced apart in the X direction (front and back), are fixed to each of the left and right base beams 15 and stand upright in the Z direction. The upper ends of the four columns 31 support the four corners of a rectangular base frame 33 that surrounds a horizontal plane. A Y-axis rail 35 extending in the Y direction is supported on the base frame 33. An X-axis rail 37 extending in the X direction is supported on the Y-axis rail 35. A Z-axis rail 39 extending in the Z direction is supported on the X-axis rail 37.

[0016] A moving body 41 is provided on the Z-axis rail 39 so as to be movable up and down (in the Z direction). The moving body 41 may also be referred to as an actuator. The Z-axis rail 39 is translated along the X-axis rail 37 in the front-to-rear direction (X direction) perpendicular to the Z-axis rail 39. The X-axis rail 37 is translated along the Y-axis rail 35 in the left-to-right direction (Y direction) perpendicular to the X-axis rail 37 and the Z-axis rail 39. Therefore, the moving body 41 is movable up and down (in the Z direction), front and back (in the X direction), and left and right (in the Y direction) relative to the stage 25.

[0017] The Z-axis rail 39 that moves the movable body 41, the X-axis rail 37 that moves the Z-axis rail 39 in a direction perpendicular to the Z-axis rail 39, and the Y-axis rail 35 that moves the X-axis rail 37 in a direction perpendicular to the X-axis rail 37 and the Z-axis rail 39 constitute an Cartesian robot 43. The robot device 13 according to the first embodiment is configured by providing the Cartesian robot 43 with a suction hand 11. That is, the Cartesian robot 43 holds the suction hand 11 so that it can move freely in three mutually perpendicular directions. The Cartesian robot 43 also has motors and the like that supply driving forces to move the rails of each axis.

[0018] The robot device 13 also includes a control device (not shown) that controls each component of the robot device 13 (for example, the suction hand 11 and the Cartesian robot 43).

[0019] A vacuum generator 45 is provided above the movable body 41. A support pipe 47 extending in the Z direction is fixed to the lower side of the movable body 41. The upper end (one end) of the support pipe 47 is fixed to the movable body 41 by a mounting piece (not shown). The vacuum generator 45 is connected to the upper end of the support pipe 47 by a connecting tube (not shown). In other words, the inner diameter side of the support pipe 47 forms a vacuum path communicating with the vacuum generator 45. The movable body 41 and the vacuum generator 45 are included in the robot device 13, and may be included in the suction hand 11 or the Cartesian robot 43.

[0020] A suction pad 49 for suctioning the object 27 is fixed to the lower end (end) of the support pipe 47 .

[0021] FIG. 2 is a side view of the suction pad 49. As shown in FIG.

[0022] The suction pad 49 according to the first embodiment is a bellows-type suction pad. The suction pad 49 includes a first pad 51 and a second pad 53 that is larger in outer shape than the first pad 51 and covers the outside of the first pad 51. The first pad 51 includes a skirt portion 55, a bellows tube 57 connected to the skirt portion 55, and a cover 59 attached to the bellows tube 57 and covering the skirt portion 55 from above. The cover 59 prevents the skirt portion 55 from curling up.

[0023] The second pad 53 has a skirt portion 61, a bellows tube 63 connected to the skirt portion 61, and a cover 65 attached to the bellows tube 63 and covering the skirt portion 61 from above. The cover 65 prevents the skirt portion 61 from curling up.

[0024] A first stay 67 is provided inside the bellows tube 63, and the first stay 67 connects to the upper end of the bellows tube 57. A second stay 69 is attached to the upper end of the bellows tube 63, and the second stay 69 is supported by the support pipe 47. In other words, the suction pad 49 is entirely supported by the second stay 69 fixed to the support pipe 47. A valve 71 is provided inside the bellows tube 63, sandwiched between the first stay 67 and the second stay 69. The valve 71 opens as the flow rate of the fluid passing through decreases, and closes as the flow rate increases. The valve 71 is also referred to as a fall prevention valve (suction assist valve). One or more valves 71 may be provided, but providing only one valve 71 can prevent a decrease in suction force.

[0025] FIG. 3 is a perspective view of the first stay 67 to which the first pad 51 is connected.

[0026] The space inside the first pad 51 forms the first space 73. The bellows tube 57 has its upper opening inserted into the outer periphery of a connecting tube 75 formed coaxially on the first stay 67, and is connected to the first stay 67. The first space 73 opens to form a suction opening on the underside of the first pad 51. A plurality of ribs 77 are radially arranged on the inside of the skirt portion 55. The ribs 77 are wedge-shaped and become thinner radially outward from the skirt portion 55, making it easier to suction the bag. The ribs 77 are similarly formed on the skirt portion 61 of the second pad 53 (see the figure). An inlet pipe 79 of the valve 71 is provided on the first stay 67, offset radially outward from the connecting tube 75.

[0027] FIG. 4 is a side view of the bellows tube 63 of the suction pad 49 with a cutaway.

[0028] The first space 73 is connected to a third space 81, which is connected to the vacuum path, without passing through a valve 71. The bellows tube 63 is connected to the second stay 69 by having its upper opening inserted into the outer periphery of a connecting tube 83 formed coaxially on the second stay 69. A support tube 85, which is connected to the support pipe 47, is formed coaxially on the upper surface of the second stay 69. A male thread is formed on the outer periphery of the support tube 85, which screws onto the support pipe 47. The third space 81, which is on the underside of the second stay 69, communicates with the vacuum path of the support pipe 47 through this support tube 85.

[0029] The suction pad 49 forms a second space 87 that is a space inside the second pad 53 and outside the first pad 51 (the bellows tube 57). The second space 87 is connected to a third space 81 above the first stay 67 via a valve 71.

[0030] FIG. 5 is a perspective view of the first stay 67 as seen from above (the third space side).

[0031] The first stay 67 is formed with a first hole 89 that connects the first space 73 and the third space 81. The first hole 89 is the inner diameter portion of the connecting pipe 75 to which the first pad 51 is connected. The first stay 67 is also formed with a second hole 91 that connects the second space 87 and the valve 71, for example, in series. The second hole 91 is provided inside the inlet pipe 79 shown in FIG. 3. The inlet pipe 79 is a pipe joint that is connected to the valve 71.

[0032] As described above, the underside of the second stay 69 shown in FIG. 4 communicates with the vacuum path of the support pipe 47 through the support pipe 85. That is, the inner diameter portion of the support pipe 85 forms a third hole 93 that penetrates the second stay 69 and communicates with the third space 81. That is, the third hole 93 connects the third space 81 to the vacuum path. The third space 81 shown in FIG. 4 is formed by the space surrounded by the inner circumferential surface of the second pad 53, the first stay 67, and the second stay 69. The shaft-shaped valve 71 is arranged vertically in this third space 81.

[0033] As shown in FIG. 2, in the suction pad 49, the first pad 51 is disposed so as to protrude downward from the second pad 53.

[0034] As shown in FIG. 2, the valve 71 is disposed in the third space 81 off the central axis 95 .

[0035] FIG. 6 is a side view of the first stay 67 to which the first pad 51 is attached.

[0036] A support 97 is disposed at the position of the central axis 95 in the third space 81. The support 97 is cylindrical and disposed coaxially with the first stay 67 and the second stay 69, and with the first pad 51. The support 97 acts as a stopper that prevents the second stay 69 and the valve 71 from approaching each other more than a certain distance when the second pad 53 is compressed, thereby ensuring a flow path for the valve 71 when the second pad 53 is compressed. Furthermore, because the valve 71 is disposed off the central axis 95, if the valve 71 were present alone, the parallel relationship between the first stay 67 and the second stay 69 would not be maintained when the second pad 53 is compressed. Therefore, the support 97 is provided to maintain this parallel relationship.

[0037] As shown in Figure 5, the support body 97 has a notch 99 cut into a portion of its circumference along a central axis 95 (see Figure 6). The valve 71 is arranged vertically in this notch 99. By being arranged in the notch 99, the valve 71 is substantially contained within the outer circumferential circle of the support body 97. As a result, the arrangement of the support body 97 and the valve 71 prevents the second pad 53 from becoming enlarged without encroaching on the third space 81, contributing to the compactness of the suction pad 49.

[0038] FIG. 7 is an explanatory diagram showing the vacuum path of the suction pad 49.

[0039] The suction pad 49 has a dual vacuum path. That is, below the first stay 67 (the suction opening side), the path is divided into a first space 73 in the first pad 51 and a second space 87 in the second pad 53. In the first path, air A sucked from the first space 73 passes through a first hole 89 (see FIG. 5) in the first stay 67 and enters the third space 81. In the second path, air B sucked from the second space 87 passes through a second hole 91 (see FIG. 5) in the first stay 67 and the valve 71 in series and enters the third space 81. Air A and air B then join in the third space 81 and are sucked into the vacuum path of the support pipe 47 through a third hole 93 (the hole of the inlet pipe 79 in FIG. 3) in the second stay 69.

[0040] FIG. 8 is a side view of the suction pad 49 in which the object 27 is sucked by the first pad 51. As shown in FIG.

[0041] When the suction pad 49 suctions an object 27 that is larger than the first pad 51 but smaller than the second pad 53, the suction opening of the first pad 51 is blocked by the object 27. The third space 81 is created under negative pressure as air C is sucked in through the vacuum path. Meanwhile, air B flows into the second space 87 of the second pad 53, whose suction opening is not completely blocked by the object 27, through the gap between the suction opening and the object 27. The air B in the second space 87 is sucked into the third space 81 via the valve 71.

[0042] Therefore, the valve 71 is gradually closed. When the valve 71 is almost closed, the third space 81 is depressurized to a negative pressure substantially equal to that of the vacuum path. As a result, the first pad 51 in the first space 73, which has become substantially equal to that of the third space 81 connected to the vacuum path, can adsorb the object 27.

[0043] The suction force of the suction pad 49 changes as the valve opening of the valve 71 changes from open to closed. It is also necessary to consider the passage of a small amount of fluid through the valve 71 even when the valve 71 is fully closed. As an example, it has been found that when the first pad 51 of the suction pad 49 is capable of suctioning an object 27 having a diameter of about 30 mm and weighing about 0.6 kg, the vacuum loss of the first pad 51 due to air leaking from the valve 71 is about 5 to 27%.

[0044] FIG. 9 is a side view showing the suction pad 49 with the object 27 sucked by the first pad 51 and the second pad 53 together with a perspective view of the main part.

[0045] When the suction pad 49 suctions an object 27 larger than the second pad 53, the first pad 51 and the second pad 53 are blocked by the object 27. Air is sucked into the third space 81 through the vacuum path, creating a negative pressure lower than the atmospheric pressure. This negative pressure acts on the second space 87 and the first space 73. The valve 71 remains open because only a small amount of air, equivalent to the volume of the second space 87, flows through it. As a result, the second space 87 and the first space 73 are decompressed to a low pressure equivalent to that of the third space 81, and the object 27 is suctioned by both the first pad 51 and the second pad 53.

[0046] As an example, the suction pad 49 can suction an object 27 weighing approximately 3 kg when the second pad 53 has a diameter of approximately 75 mm. Furthermore, when the center of gravity of the object 27 is offset, the suction pad 49 can suction the object at an angle by bending the bellows tube 63. It has been found that the maximum angle of inclination in this case is approximately 45°.

[0047] FIG. 10 is an explanatory diagram showing the correlation between the pressing force of the suction pad 49 applied to the target object 27 and the retraction stroke caused by the reaction force.

[0048] In normal operation, the first pad 51 of the suction pad 49 protrudes by a distance S1 from the second pad 53. When the suction pad 49 presses the target object 27 with a pressing force F1, it contracts by a pre-stroke S1 from the no-load state. When the suction pad 49 presses the target object 27 with a pressing force F2, it contracts by a stroke S2 ​​from the no-load state. When the suction pad 49 presses the target object 27 with a pressing force F3, it contracts by a full stroke S3 from the no-load state.

[0049] For example, the pressing force F1 is a preload of 200 g, and the prestroke S1 at this time is 5 mm. The pressing force F2 is an approach load of 500 g, and the approach stroke S2 ​​at this time is 15 mm. The pressing force F3 is a full load of 850 g, and the full stroke S3 at this time is 20 mm.

[0050] FIG. 11 is an explanatory diagram showing the dimensional changes of each portion of the suction pad 49 from the no-load state to the full stroke.

[0051] In the unloaded state, the distance from the suction opening to the first stay 67 of the suction pad 49 is M1, and the distance from the first stay 67 to the second stay 69 is M2. When all of the suction pads 49 are in contact with the target object 27, the suction pads 49 are shortened by a distance M3 from the unloaded state. At this time, the distance from the suction opening to the first stay 67 of the suction pad 49 is M4, and the distance from the first stay 67 to the second stay 69 is M5. Furthermore, when all of the suction pads 49 are in contact with the target object 27 at their full stroke, the suction pads 49 are shortened by a distance M6 from the unloaded state. At this time, the distance from the suction opening to the first stay 67 of the suction pad 49 is M7, and the distance from the first stay 67 to the second stay 69 is M8.

[0052] As an example, the distance M1 is 28 mm, the distance M2 is 24 mm, the distance M3 is 10 mm, the distance M4 is 21 mm, the distance M5 is 21 mm, the distance M6 is 20 mm, the distance M7 is 18 mm, and the distance M8 is 14 mm.

[0053] FIG. 12 is a front view showing an example of the suction hand 11 equipped with the imaging device 101 and the rotation mechanism 103. As shown in FIG.

[0054] The suction hand 11 according to the first embodiment can include, in addition to the suction pad 49 that suctions the object 27, an imaging device 101 that images the object 27, and a rotation mechanism 103 that rotates the suction pad 49. The rotation mechanism 103 rotates the suction pad 49 within a plane along which the central axis 95 of the suction pad 49 is aligned.

[0055] The imaging device 101 is a camera equipped with an imaging element. The imaging device 101 is supported by a bracket 105 attached to the support pipe 47. A motor 107 of a rotation mechanism 103 is fixed to the bracket 105. The motor 107 has a pinion gear fixed to its output shaft that meshes with a segment gear 109 provided on the suction pad 49. The bracket 105, motor 107, and segment gear 109 constitute the rotation mechanism 103. In this configuration, the suction pad 49 is supported by the support pipe 47 with the center of rotation of the segment gear 109 being rotatable about a rotation shaft 111. The rotation shaft 111 intersects (is perpendicular to) the central axis 95 of the support pipe 47. In other words, the suction pad 49 rotates around a horizontal axis. Here, the rotation around the horizontal axis is referred to as tilt rotation T (see arrow T in FIG. 12 ).

[0056] The rotation mechanism 103 allows the suction pad 49 to tilt in a range from a position in which the central axis 95 is aligned at least vertically to a position in which the central axis 95 is aligned horizontally.

[0057] The imaging device 101 is disposed at a height H1 from the suction opening position of the first pad 51. When the suction pad 49 is oriented such that the central axis 95 is horizontal, the distance from the center of the support pipe 47 to the suction opening of the first pad 51 is L1. Furthermore, the distance from the center of the support pipe 47 to the outermost part of the imaging device 101 of the suction pad 49 is L2, and the distance from the center of the support pipe 47 to the optical axis of the imaging device 101 is L3.

[0058] For example, H1 is 93 mm, L1 is 70 mm, L2 is 57.5 mm, and L3 is 45 mm.

[0059] FIG. 13 is a plan view of FIG.

[0060] The suction pad 49 may be supported rotatably about the central axis of the support pipe 47. That is, the suction pad 49 and the imaging device 101 rotate about a vertical axis. Here, rotation about the vertical axis is referred to as pan rotation P (see arrow P in FIG. 13 ). A pan rotation mechanism (not shown) that pans the suction pad 49 and the imaging device 101 may be, for example, a mechanism that rotates the support pipe 47. In this case, the pan rotation mechanism may be provided on the moving body 41 (see FIG. 1 ).

[0061] FIG. 14 is an explanatory diagram showing the tilt rotation state of the suction pad 49.

[0062] In the normal state, the suction hand 11 is disposed so that the imaging device 101 is offset radially outward from the central axis 95 of the suction pad 49 (see the left diagram in FIG. 14 ). For this reason, the imaging device 101 may not be able to see the target object 27 due to the suction pad 49 getting in the way. The suction hand 11 can be tilted T by the rotation mechanism 103 to a position where the suction pad 49 is retracted so as not to interfere with the angle of view of the imaging device 101 (see the center and right diagrams in FIG. 14 ).

[0063] Next, the operation of the above-described configuration will be described.

[0064] The suction pad 49 according to the first embodiment is a suction pad 49 that suctions an object 27, and may include a first pad 51, a second pad 53 that is larger in outer shape than the first pad 51 and covers the outside of the first pad 51, and a valve 71 that opens as the flow rate of a fluid passing through decreases and closes as the flow rate increases. A first space 73 that is the space inside the first pad 51 may be connected to a third space 81 that is connected to a vacuum path without passing through the valve 71. A second space 87 that is the space inside the second pad 53 and outside the first pad 51 may be connected to the third space 81 via the valve 71.

[0065] The suction pad 49 according to the first embodiment includes a first pad 51 and a second pad 53 that covers the outside of the first pad 51. The suction opening of the first pad 51 is disposed inside the suction opening of the second pad 53. A first space 73 inside the first pad 51 is connected to a third space 81. The third space 81 is connected to a vacuum path.

[0066] The second space 87, which is the space inside the second pad 53 and outside the first pad 51, is connected to the third space 81 via the valve 71. The valve 71 opens as the flow rate of the fluid (air) passing through decreases, and closes as the flow rate of air increases. That is, the valve 71 remains open when there is no pressure difference between the second space 87 and the third space 81. On the other hand, the valve 71 gradually closes when the pressure in the third space 81 is low and a large amount of air flows from the second space 87 to the third space 81.

[0067] When the suction pad 49 suctions an object 27 whose suction surface is larger than the suction opening of the first pad 51 and smaller than the suction opening of the second pad 53, the suction opening of the first pad 51 is blocked by the suction surface of the object 27. Air is sucked into the third space 81 by the vacuum path, creating a negative pressure lower than the atmospheric pressure. This negative pressure acts on the first space 73 whose suction opening is blocked by the object 27.

[0068] The second space 87 of the second pad 53, whose suction opening is not completely blocked by the object 27, is open to the outside air through the gap between the suction opening and the attracted surface. The second space 87 is connected to the third space 81 via the valve 71. When the third space 81 becomes negative pressure, the air in the second space 87 flows into the third space 81 through the valve 71. Therefore, the valve 71 is gradually closed.

[0069] When the valve 71 is almost closed, air does not flow from the second space 87 to the third space 81. As a result, the third space 81 is depressurized to the same negative pressure as the vacuum path. That is, the object 27 can be adsorbed by the first pad 51 in the first space 73, which has become equivalent to the third space 81 connected to the vacuum path.

[0070] Note that, by closing the valve 71, negative pressure is no longer applied to the second space 87. Although the second pad 53 no longer has an adsorption function, a portion of the circumferential direction of the adsorption opening comes into contact with the object 27, thereby suppressing lateral movement of the object 27.

[0071] On the other hand, when the suction pad 49 suctions an object 27 whose suction surface is larger than the suction opening of the second pad 53, the suction openings of the first pad 51 and the second pad 53 are blocked by the suction surface of the object 27. Air is sucked into the third space 81 through the vacuum path, creating a negative pressure lower than the atmospheric pressure. This negative pressure acts on the second space 87 of the second pad 53, whose suction opening is blocked by the object 27, and the first space 73 of the first pad 51.

[0072] At this time, the valve 71 remains open because only a small amount of air flows, equivalent to the volume of the second space 87. As a result, the second space 87 and the first space 73 are depressurized to a low pressure equivalent to that of the third space 81. In other words, the object 27 can be stably adsorbed by both the first pad 51 and the second pad 53.

[0073] As a result, the suction pad 49 can suction the object 27, whether it is a box, a bag, large or small, without having to recognize information about the object 27 before suction.

[0074] The suction pad 49 may further include a first stay 67 having a first hole 89 connected to the first space 73 and a second hole 91 connecting the second space 87 in series with the valve 71, and a second stay 69 having a third hole 93 connected to the second pad 53 and connected to the vacuum path. The third space 81 is a space surrounded by the second pad 53, the first stay 67, and the second stay 69, and the valve 71 may be disposed in the third space 81.

[0075] In this suction pad 49, the inside of the second pad 53 is partitioned from the suction opening by a first stay 67 and a second stay 69 spaced apart from the first stay 67. The inner space of the second pad 53 partitioned by the first stay 67 and the second stay 69 forms a third space 81.

[0076] The first pad 51 is connected to the suction opening side of the second pad 53 of the first stay 67. The second pad 53 is located inside the space outside the first pad 51, and a second space 87 is formed between the first stay 67 and the suction opening of the second pad 53. A first hole 89 is formed in the first stay 67, connecting the first space 73 of the first pad 51 to the third space 81. In addition, a second hole 91 is formed in the first stay 67, connecting the second space 87 and the valve 71 in series.

[0077] A valve 71 is disposed in the third space 81. The valve 71 has an air inlet connected to the second hole 91 and an air outlet that is open in the third space 81. In other words, the second space 87 and the valve 71 are connected in series by the second hole 91. A third hole 93 that connects the third space 81 to the vacuum path is formed in the second stay 69.

[0078] In the suction pad 49, the inside of the second pad 53 is partitioned by two stays, a first stay 67 and a second stay 69, to form a second space 87 and a third space 81. The first stay 67, which supports the first pad 51, is supported by the second pad 53. The second pad 53 is supported by the second stay 69. The valve 71 is housed in the third space 81, which is the largest.

[0079] As a result, the suction pad 49 can accommodate the components necessary for suction, including the valve 71 and the flow paths that separate the three chambers and connect the respective chambers, with a small number of parts, and all components can be supported only by the second stay 69, thereby achieving miniaturization.

[0080] In the suction pad 49, the first stay 67 may be provided inside the second pad 53, and the second space 87 and the third space 81 may be located inside the second pad 53. In this case, both the first stay 67 and the second stay 69 of the suction pad 49 can be disposed inside the second pad 53, and the suction pad 49 can be made smaller.

[0081] In the suction pad 49 , the first pad 51 may be disposed so as to protrude from the second pad 53 .

[0082] In this suction pad 49, the first pad 51 may be arranged in a state where it protrudes from the second pad 53. When the suction pad 49 approaches the object 27, the first pad 51 first comes into contact with the object 27. When the suction pad 49 further approaches the object 27, if the object 27 is larger than the second pad 53, the second pad 53 comes into contact with the object 27. When the second pad 53 comes into contact with the object 27, the suction force of the second pad 53 increases, and the object 27 is adsorbed.

[0083] As a result, the suction pad 49 stably suctions the object 27 with both the second pad 53 and the first pad 51. Note that if the object 27 is smaller than the second pad 53 (if it does not come into contact with the second pad 53), the valve 71 operates as described above, and the object 27 is suctioned only by the first pad 51.

[0084] In the suction pad 49 , the valve 71 is disposed in the third space 81 away from the central axis 95 , and a support 97 may be disposed in the third space 81 at the position of the central axis 95 .

[0085] In this suction pad 49, the valve 71 is positioned in the third space 81 away from the central axis 95. Meanwhile, a support 97 is positioned at the position of the central axis 95 in the third space 81. The second pad 53 contracts when it sucks the object 27. At this time, the first stay 67 approaches the second stay 69, but the support 97 located on the central axis 95 comes into contact with the first stay 67. As a result, the valve 71, which is positioned away from the central axis 95, comes into contact with the first stay 67, preventing the first stay 67 from tilting. As a result, the second pad 53 is prevented from bending when it sucks the object 27.

[0086] In the suction pad 49 , the support 97 may be formed in a cylindrical shape and disposed coaxially with the first pad 51 .

[0087] In this suction pad 49, the support 97 is formed as a cylinder. The support 97 is provided coaxially with the first stay 67 and the second stay 69. The second pad 53 contracts when it attracts the object 27. At this time, the first stay 67 and the second stay 69 are supported by the cylindrical support 97 that is disposed about a central axis 95. As a result, the first stay 67 and the second stay 69 sandwich the support 97, which is positioned concentrically with the central axis 95, and are therefore supported in a more stable, parallel state without tilting.

[0088] In the suction pad 49 , the support 97 has a notch 99 cut out along a central axis 95 in a part of its circumference, and the valve 71 may be disposed in the notch 99 .

[0089] In this suction pad 49, the support body 97 has a notch 99 cut out in a circumferential portion along the central axis 95. That is, the support body 97 has a C-shape when viewed from the direction along the central axis 95, with the sides open. A shaft-shaped valve 71 is arranged in this notch 99 along the central axis 95. The valve 71 is arranged in the notch 99 with a gap formed inside.

[0090] When the second pad 53 contracts due to suction, the support 97 is sandwiched between the first stay 67 and the second stay 69. The support 97 is C-shaped with its sides open to the third space 81. As a result, even when both ends of the support 97 of the suction pad 49 are sandwiched between the first stay 67 and the second stay 69, air in the first space 73 is sucked in through the third hole 93 via the first hole 89 and the inside of the cylinder, and air in the third space 81 is sucked in through the notch 99 via the third hole 93.

[0091] Furthermore, since the valve 71 is disposed in the notch 99 of the suction pad 49, the radial expansion of the pad 49 can be suppressed, thereby enabling the pad 49 to be made smaller.

[0092] The suction hand 11 according to embodiment 1 is an suction hand 11 that suctions an object 27, and may include an imaging device 101 that images the object 27, an suction pad 49, and a rotation mechanism 103 that rotates the suction pad 49 within a plane along the central axis 95 of the suction pad 49.

[0093] The suction hand 11 according to the first embodiment is provided with an imaging device 101 that captures an image of the target object 27. The suction hand 11 is also provided with a rotation mechanism 103 that rotates the suction pad 49. The rotation mechanism 103 rotates the suction pad 49 within a plane along the central axis 95 of the suction pad 49. The imaging device 101 is attached so that the imaging direction (the optical axis of imaging light) is parallel to and in the same direction as the central axis 95 of the suction pad 49.

[0094] Because the imaging device 101 of the suction hand 11 is positioned (offset) radially outward from the central axis 95 of the suction pad 49, the suction pad 49 may get in the way and obscure the object 27. In other words, the suction pad 49 may obstruct the field of view (imaging range) of the imaging device 101, causing at least a portion of the suction pad 49 to appear in the image captured by the imaging device 101, thereby obscuring the object 27. Therefore, the suction hand 11 can be moved by the rotation mechanism 103 to a position where the suction pad 49 is retracted so that the angle of view of the imaging device 101 is not obstructed, i.e., so that the object 27 appears in the image captured by the imaging device 101. This prevents the object 27 from becoming invisible. The captured image obtained in this manner makes it possible to reliably recognize the object 27 based on the captured image, and information about the object (e.g., shape, size, color, and object identification information) can be obtained.

[0095] Therefore, with the suction pad 49 and suction hand 11 according to the first embodiment, the object 27 can be picked up without having to recognize information about the object 27 to be picked up before picking it up.

[0096] In the first embodiment, the third space 81 is located inside the second pad 53, but this is not limiting. The third space 81 may be located outside the second pad 53. In this case, the first stay 67 may be located at the position of the second stay 69.

[0097] In the first embodiment, the first pad 51 may not protrude beyond the second pad 53, and may be located inside the second pad 53. In this case, the second pad 53 will come into contact with the object 27 before the first pad 51 does.

[0098] In the first embodiment, the cover 65 may be made of a sponge-like material or a deformable material. In this case, the suction pad 49 can prevent the second pad 53 from being turned up, and the cover 65 can be prevented from interfering with the second pad 53.

[0099] (Embodiment 2) Next, a description will be given of a suction pad according to embodiment 2. The same components as those in embodiment 1 will be given the same reference numerals as those in the embodiment, and the description will be omitted or simplified.

[0100] Fig. 15 is a side view showing a schematic configuration of a suction pad according to embodiment 2. As shown in Fig. 15, suction pad 49A according to embodiment 2 is a bellows type formed in a bellows shape, similar to suction pad 49 according to embodiment 1. Suction pad 49A includes first pad 51 having skirt portion 55, bellows tube 57, and cover 59, and second pad 53 having skirt portion 61, bellows tube 63, and cover 65.

[0101] In the suction pad 49A, the space inside the first pad 51 is the first space, and the space inside the connecting pipe 100 is the third space. The space inside the second pad 53 and outside the first pad 51 and the connecting pipe 100 is the second space 87.

[0102] The connecting pipe 100 has, for example, a cylindrical shape with openings at the upper and lower ends, and is disposed at a position concentric with the central axis 95. The connecting pipe 100 connects the second stay 69 fixed to the support pipe 47 to the first pad 51. The first space inside the first pad 51 communicates with the vacuum path of the support pipe 47 through a third space inside the connecting pipe 100.

[0103] A shaft-shaped valve 71 is arranged sideways (with the axis of the valve 71 perpendicular to the central axis 95) in the second space 87 inside the second pad 53. The valve 71 is connected to the third space inside the connecting pipe 100 through a hole (not shown) formed in the side wall of the connecting pipe 100. With this configuration, the second space inside the second pad 53 communicates with the vacuum path of the support pipe 47 through the valve 71 and the third space inside the connecting pipe 100.

[0104] By adopting the configuration of the second embodiment, a member corresponding to the first stay 67 in the first embodiment becomes unnecessary.

[0105] (Summary of the embodiment) As described above, the present disclosure describes at least the following matters. Note that, in parentheses, examples of components corresponding to the above-described embodiment are shown, but the present disclosure is not limited to these.

[0106] (Item 1) A suction pad (suction pad 49) that suctions an object (object 27), comprising: a first pad (first pad 51); a second pad (second pad 53) that is larger in outer shape than the first pad and covers the outside of the first pad; and a valve (valve 71) that opens as the flow rate of a fluid passing through decreases and closes as the flow rate increases, wherein a first space (first space 73) that is the space inside the first pad is connected to a third space (third space 81) that is connected to a vacuum path without going through the valve, and a second space (second space 87) that is the space inside the second pad and outside the first pad is connected to the third space via the valve.

[0107] This allows the suction pad to stably perform both suction with the first pad and suction with the second pad, and therefore the suction pad can suction an object whose type is unknown, such as a box, bag, large or small, without having to recognize information about the object before suction.

[0108] (Item 2) The suction pad according to item 1, further comprising: a first stay (first stay 67) to which the first pad is connected and which has a first hole (first hole 89) connected to the first space and a second hole (second hole 91) connecting the second space and the valve; and a second stay (second stay 69) to which the second pad is connected and which has a third hole (third hole 93) connected to the vacuum path, wherein the third space is a space surrounded by the second pad, the first stay, and the second stay, and in which the valve is disposed.

[0109] As a result, the suction pad can be made compact using a small number of parts, as it can separate the three chambers, contain the components necessary for suction including the flow paths connecting each chamber and the valve 71, and each component can be supported by the second stay.

[0110] (Item 3) The suction pad according to Item 2, wherein the first stay is provided inside the second pad and the third space is inside the second pad. This allows both the first stay and the second stay to be positioned inside the second pad, making the suction pad smaller.

[0111] (Item 4) The suction pad according to any one of items 1 to 3, wherein the first pad is disposed so as to protrude from the second pad.

[0112] As a result, when the second pad can perform suction, the suction pad can perform suction using the second pad alone. Also, when the second pad alone cannot perform suction, the suction pad can stably suction the object by combining the second pad and the first pad.

[0113] (Item 5) The suction pad according to any one of items 1 to 4, wherein the valve is positioned in the third space away from a central axis (central axis 95), and a support (support 97) is positioned in the third space at the position of the central axis.

[0114] As a result, when the second pad contracts by sucking an object, the support member located on the central axis and the valve located off the central axis come into contact with the first stay, preventing the first stay from tilting. Thus, the suction pad can prevent the second pad from bending when the object is sucked.

[0115] (Item 6) The suction pad according to Item 5, wherein the support is formed in a cylindrical shape and is disposed coaxially with the first pad.

[0116] As a result, when the second pad contracts to suck an object, the first and second stays are supported by the support body arranged around the central axis, and the first and second stays sandwich the support body that is positioned concentrically with the central axis, preventing tilting and supporting the suction pad in a more stable, parallel state.

[0117] (Item 7) The suction pad according to Item 5 or 6, wherein the support has a notch (notch 99) cut out along the central axis in a circumferential portion thereof, and the valve is disposed in the notch.

[0118] As a result, even when both ends of the support body of the suction pad are sandwiched between the first stay and the second stay, air in the first space can be sucked through the first hole and inside the support body and through the third hole, and air in the third space can be sucked through the notch and through the third hole. In addition, because the valve is disposed in the notch, the suction pad can be made smaller by suppressing radial expansion.

[0119] (Item 8) A suction hand (suction hand 11) that suctions an object, the suction hand comprising: the suction pad according to any one of items 1 to 7; an imaging device (imaging device 101) that images the object; and a rotation mechanism (rotation mechanism 103) that rotates the suction pad within a plane along the central axis of the suction pad.

[0120] As a result, the suction hand can be adjusted by rotating the suction pad with the rotation mechanism so that the object is properly reflected in the captured image taken by the imaging device, thereby enabling stable recognition of the object based on the captured image.

[0121] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0122] The present disclosure is useful for a suction pad, a suction hand, and the like that can suction an object without recognizing information about the object to be suctioned before suction.

[0123] REFERENCE SIGNS LIST 11 suction hand 27 object 49 suction pad 51 first pad 53 second pad 67 first stay 69 second stay 71 valve 73 first space 81 third space 87 second space 89 first hole 91 second hole 93 third hole 95 central axis 97 support 99 notch 101 imaging device 103 rotation mechanism

Claims

1. A suction pad for suctioning an object, comprising: a first pad; a second pad which is larger in outer shape than the first pad and covers the outside of the first pad; and a valve which opens as the flow rate of a fluid passing through decreases and closes as the flow rate increases, wherein the first space, which is the space inside the first pad, is connected to a third space which is connected to a vacuum path without going through the valve; and a second space, which is the space inside the second pad and outside the first pad, is connected to the third space via the valve.

2. The suction pad according to claim 1, further comprising: a first stay to which the first pad is connected and which has a first hole connected to the first space and a second hole connecting the second space and the valve; and a second stay to which the second pad is connected and which has a third hole connected to the vacuum path, wherein the third space is a space surrounded by the second pad, the first stay, and the second stay, and in which the valve is located.

3. The suction pad according to claim 2, wherein the first stay is provided inside the second pad, and the third space is located inside the second pad.

4. The suction pad according to any one of claims 1 to 3, wherein the first pad is disposed so as to protrude from the second pad.

5. The suction pad according to claim 2, wherein the valve is positioned off the central axis in the third space, and a support is positioned at the position of the central axis in the third space.

6. The suction pad according to claim 5, wherein the support is formed in a cylindrical shape and is arranged coaxially with the first pad.

7. The suction pad according to claim 5 or 6, wherein the support has a notch cut into a circumferential portion along the central axis, and the valve is disposed in the notch.

8. A suction hand for suctioning an object, comprising: the suction pad according to claim 1; an imaging device for imaging the object; and a rotation mechanism for rotating the suction pad within a plane along the central axis of the suction pad.

Images