Hand, conveyance device, and method for conveying conveyed object

Abstract

Provided are a hand using pads capable of adhering to and holding even a conveyed object in which warpage has occurred, a conveyance device to which the hand is mounted, and a method for conveying a conveyed object using the conveyance device.　The hand comprises: a hand body; a first ventilation path; a second ventilation path; first pads that communicate with the first ventilation path and adhere to a conveyed object; and second pads that communicate with the second ventilation path and suction the conveyed object. A plurality of the first pads and the second pads are provided to the hand body, and the suction amount of the first pads is lower than that of the second pads. The conveyance device comprises the hand, a conveyance robot, a switching unit that switches the communication state of each of the first ventilation path and the second ventilation path, and a control unit. The method for conveying a conveyed object includes: a suction step that is executed by the conveyance device and in which a conveyed object is suctioned; a blocking step in which the second ventilation path is transitioned to a blocked state after the pads adhere to and hold the conveyed object; and a conveyance step in which the conveyed object is conveyed.

Description

Hand, conveying device, and method for conveying an object

[0001] The present invention relates to a hand, a transport device, and a method for transporting an object.

[0002] In the field of semiconductor manufacturing and the like, there has been a conventional technique in which a transport device transports objects (e.g., wafers, glass substrates, etc.) contained in a storage container called a FOUP (Front Opening Unified Pod) from the FOUP to various processing devices, and the transported objects are processed. The transport device includes a transport robot as a transport mechanism, which includes a robot arm that can move vertically and horizontally, and a hand that is attached to the robot arm and has a suction member such as a pad that suction-holds the object. For example, a known method of transporting an object using a transport robot is to remove the object from the storage container by moving the robot arm while the hand suction-holds the object.

[0003] If the transported object is warped or distorted, some of the pads may not come into contact with the transported object when the object is transported while being held by suction. In this case, air may flow in through the gap between the pad and the transported object, reducing the suction pressure and potentially reducing the pad's ability to hold the transported object by suction (hereinafter referred to as "holding force"). Patent Document 1 proposes a hand that limits the amount of air that flows in through the gap between the pad and the transported object per unit time and thereby prevents a decrease in suction pressure by setting the air flow path of the pad to a small diameter and intentionally reducing the amount of air that the pad sucks in per unit time (suction volume).

[0004] Japanese Patent Application Laid-Open No. 2022-51595

[0005] In the hand of Patent Document 1, the amount of air suction by the pad decreases, so the force attracting the transported object to the pad (hereinafter referred to as suction force) decreases. In this case, the pad cannot attract the transported object to the suction surface of the pad, and the total number of pads that suction and hold the transported object decreases, which may result in insufficient holding force.

[0006] For these reasons, there is a need for a hand that can adsorb and hold the transported object by ensuring the suction force of the pad while suppressing the inflow of air through the gap between the transported object and the pad, a transport device to which such a hand is attached, and a method for transporting the transported object using the transport device.

[0007] Therefore, the present invention provides a hand using a pad that can adsorb and hold even warped objects, a transport device to which the hand is attached, and a method for transporting objects using the transport device.

[0008] In order to achieve the above object, according to the present invention, there is provided a hand that is attached to a conveying device and holds a conveyed object, comprising a hand body, a first air passage connected to a vacuum source, a second air passage connected to the vacuum source, a first pad that communicates with the first air passage and adsorbs the conveyed object, and a second pad that communicates with the second air passage and sucks the conveyed object, wherein a plurality of the first pads and second pads are provided on the hand body, and the first pad has a smaller suction amount than the second pad.

[0009] In order to achieve the above object, according to the present invention, there is provided a transport device comprising the hand, a transport robot that freely moves the hand, a switching unit that switches the communication state of each of the first air passage and the second air passage, and a control unit that controls the switching unit, wherein the switching unit switches the communication state between a suction state in which air suction force is applied by the vacuum source and a blocked state in which air suction force is not applied by the vacuum source.

[0010] In order to achieve the above-mentioned object, according to the present invention, there is provided a method for transporting an object by a transport device having a hand that holds the object, wherein the hand comprises a hand body, a first air passage connected to a vacuum source, a second air passage connected to the vacuum source, a first pad that communicates with the first air passage and adsorbs the object, and a second pad that communicates with the second air passage and sucks the object, wherein a plurality of the first pads and the second pads are provided on the hand body, and the first pad has a smaller suction amount than the second pad, and the method for transporting the object includes a suction step of sucking the object by the first pad that communicates with the first air passage and the second pad that communicates with the second air passage, a blocking step of switching the second air passage to a blocked state after adsorbing and holding the object, and a transport step of transporting the object to a predetermined position.

[0011] According to the present invention, it is possible to provide a hand using a pad that can adsorb and hold even warped transported objects, a transport device to which the hand is attached, and a method for transporting transported objects using the transport device.

[0012] 1. An explanatory top view of a hand according to one embodiment of the present invention. An explanatory bottom view of the hand shown in FIG. 1. A perspective view showing a transport device equipped with the hand shown in FIG. 1. An explanatory diagram of a flow path in a transport device equipped with the hand shown in FIG. 3. An enlarged cross-sectional explanatory view of the peripheral structure of the first pad and the second pad of the hand shown in FIG. 1. An explanatory top view of the peripheral structure of the first pad and the second pad of the hand shown in FIG. 5. An exploded explanatory view of the peripheral structure of the first pad of the hand shown in FIG. 5. An exploded explanatory view of the peripheral structure of the second pad of the hand shown in FIG. 6. An exploded explanatory view of the peripheral structure of the first pad of a hand according to another embodiment of the present invention. A perspective view showing a transport robot used in the transport device shown in FIG. 3. An enlarged explanatory view of the periphery of a switching unit of the transport robot shown in FIG. 10. A flowchart of a first embodiment of a method for transporting a transported object using the transport device shown in FIG. 3. A flowchart of a second embodiment of a method for transporting a transported object using the transport device shown in FIG.

[0013] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Below, a description will be given of a hand 100, a transport device 20 including the hand 100, and a flow of a method for transporting a transported object W using the transport device 20 including the hand 100, according to this embodiment, in combination with Figures 1 to 13. However, this is merely an example of the present invention, and the present invention is not limited thereto.

[0014] First, a hand 100 according to this embodiment will be described with reference to FIGS. 1 to 5. In this embodiment, the hand 100 is attached to a robot arm 211 of a transfer robot 21 of a transfer device 20 and holds a transfer object W (e.g., a wafer). The hand 100 includes a hand body 110, a first air passage 120, a second air passage 130, a first pad 140, and a second pad 150. The first air passage 120 is connected to a vacuum source V (e.g., a vacuum pump). The first pad 140 communicates with the first air passage 120 and sucks and adsorbs the transfer object W. The second air passage 130 is connected to the vacuum source V. The second pad 150 communicates with the second air passage 130 and sucks and adsorbs the transfer object W. A plurality of first pads 140 and second pads 150 (e.g., four first pads 140 and three second pads 150) are provided on the hand body 110. The first air passage 120 and the first pad 140 form a first suction system, and the second air passage 130 and the second pad 150 form a second suction system. The first pad 140 sucks in a smaller amount of air per unit time (suction volume) than the second pad 150. Here, "suction" refers to drawing the transported object W to the first pad 140 and / or the second pad 150 by the suction force of the first pad 140 and / or the second pad 150, or bringing the drawn transported object W into close contact with the first pad 140 and / or the second pad 150. "Adsorption" refers to the first pad 140 and / or the second pad 150, which are in close contact with the transported object W, holding the transported object W by negative pressure. Therefore, both the first pad 140 and the second pad 150 can suck and adsorb the transported object W, but the first pad 140, which has a small suction amount, mainly functions to adsorb the transported object W, and the second pad 150, which has a large suction amount, mainly functions to adsorb the transported object W. However, the present invention is not limited to this.

[0015] Specifically, the hand main body 110 of the hand 100 includes a base 112 provided with a first connection hole 126 connecting the first air passage 120 and the vacuum source V and a second connection hole 136 connecting the second air passage 130 and the vacuum source V, and a hand unit 114 extending from the base 112. The base 112 includes a mounting portion 111 (e.g., the hole shown in FIGS. 1 and 2 ) that is mounted to the robot arm 211 of the transfer robot 21. The hand unit 114 is provided with a first pad 140 and a second pad 150. The hand unit 114 holds the transported object W by the first pad 140 attracting the transported object W. As an example, the hand main body 110 is a substantially Y-shaped base (e.g., a plate), and the portion that branches out and extends from the base 112 corresponds to the hand unit 114. The hand unit 114 has a first finger unit 1141 corresponding to one side of a bifurcated portion extending from the base unit 112, and a second finger unit 1142 corresponding to the other side of the bifurcated portion. A first pad 140 and a second pad 150 are provided on the first finger unit 1141 and the second finger unit 1142, respectively. That is, the first finger unit 1141 is provided with the first pad 140 and the second pad 150. Similarly, the second finger unit 1142 is provided with the first pad 140 and the second pad 150. The first air passage 120 and the second air passage 130 are paths through which air can circulate, and are each provided in the hand body 110. As an example, the first air passage 120 and the second air passage 130 are formed by drilling grooves or holes inside the hand body 110 (for example, the portions indicated by dashed lines in FIGS. 1 and 4). The hand body 110 may also be constructed by bonding two plates together. That is, grooves or holes may be drilled in the underside of the upper plate of the hand body 110, and a lower plate may be attached to the upper plate as a lid to cover the grooves or holes (as described below), and the first air passage 120 and the second air passage 130 may be formed inside the hand body 110 consisting of the upper and lower plates using the grooves or holes.

[0016] Furthermore, the first ventilation path 120 has a first ventilation portion 122 provided in the base 112 along the extension direction of the hand body 110 (i.e., the left-right direction in the drawing) and communicating with the vacuum source V, first communication portions 124 provided in the hand portion 114 and communicating with the first ventilation portion 122 and each of the multiple first pads 140 provided, and first connection holes 126 connecting to the vacuum source V. The first ventilation path 120 extends from the base 112 to the hand portion 114 and communicates between the vacuum source V, which is provided on a side closer to the transport device 20 than the base 112, and the first pads 140 provided in the hand portion 114. The second air passage 130 includes a second ventilation portion 132 provided in the base 112 along the extension direction of the hand main body 110 (i.e., the left-right direction in the drawing) and communicating with the vacuum source V, a second communication portion 134 provided in the hand unit 114 and communicating with the second ventilation portion 132 and each of the plurality of second pads 150, and a second connection hole 136 connecting to the vacuum source V. The second air passage 130 extends from the base 112 to the hand unit 114 and communicates between the vacuum source V, which is provided closer to the transport device 20 than the base 112, and the second pads 150 provided in the hand unit 114. Note that the first air passage 120 and the second air passage 130 may be, for example, a metal pipe or a plastic tube attached to the hand main body 110, as long as they form a path through which air can circulate.

[0017] 5 , the hand body 110 further includes a plurality of mounting portions 116 on which the first pads 140 and the second pads 150 are mounted. The mounting portions 116 are provided on the hand unit 114 corresponding to the positions where the first pads 140 and the second pads 150 are mounted. The mounting portions 116 connect the mounting surfaces of the first pads 140 and the second pads 150 (the upper surface 114a of the hand unit 114 in this embodiment) to the first air passage 120 or the second air passage 130. For example, the mounting portions 116 are through-holes that penetrate the hand unit 114 from the upper surface 114a to the lower surface 114b of the hand unit 114. The mounting portions 116 include a plurality of first mounting portions 1161 on which the first pads 140 are mounted and a plurality of second mounting portions 1162 on which the second pads 150 are mounted. The structures of the first and second mounting portions 1161 and 1162 will be described below together with the respective structures of the first and second pads 140 and 150.

[0018] The structure around the first pad 140 of the hand 100 will be described with reference to FIGS. 1 and 5 to 7. The hand main body 110 has a plurality of first mounting portions 1161 on which the first pads 140 are mounted. The first mounting portions 1161 are provided on the hand unit 114 corresponding to the positions where the first pads 140 are mounted. The first pads 140 are mounted on the hand unit 114 of the hand main body 110 by the first mounting portions 1161. The first mounting portions 1161 form mounting openings in the upper surface 114a of the hand unit 114, into which the first pads 140 are inserted. The first mounting portions 1161 communicate between the upper surface 114a of the hand unit 114 and the first air passage 120. Specifically, the first installation portion 1161 has a large diameter portion 1161a, a small diameter portion 1161b having an inner diameter smaller than that of the large diameter portion 1161a, and a connecting portion 1161c connecting the large diameter portion 1161a and the small diameter portion 1161b. The small diameter portion 1161b is a base for attaching the first pad 140 and fits into an annular recess structure (described below) formed on the outside of the outer circumferential surface 142c of the first engagement portion 142 of the first pad 140. The large diameter portion 1161a is provided below the small diameter portion 1161b and forms a space partitioned on the inner surface of the large diameter portion 1161a, which communicates with the first air passage 120. The space partitioned on the inner surface of the large diameter portion 1161a can also be said to form part of the first communication portion 124 of the first air passage 120. As an example, a groove 114d is formed in the lower surface 114b of the hand unit 114 below the large diameter portion 1161a, and the groove 114d forms a part of the first communication portion 124 of the first air passage 120, and is covered by the lid 115. That is, at least a part of the first communication portion 124 of the first air passage 120 is formed by the groove 114d in the lower surface 114b of the hand unit 114 and the lid 115. In addition, the connection portion 1161c is a step between the large diameter portion 1161a and the small diameter portion 1161b, and serves as a limiting structure for limiting the position of the first pad 140 after it is attached to the first installation portion 1161. As an example, the hand unit 114 has a base portion 114c that protrudes upward from the upper surface 114a. The base portion 114c has a hole formed therein that forms an attachment opening into which the first pad 140 is inserted, and is disposed above the small diameter portion 1161b. The first pad 140 is attached to the first installation portion 1161 so as to rest on the base portion 114c.Furthermore, because the inner diameter of the hole drilled in the pedestal portion 114c is equal to the inner diameter of the small diameter portion 1161b, the pedestal portion 114c can also be considered to be part of the small diameter portion 1161b. The pedestal portion 114c is formed by using end mill processing to dig out portions of the upper surface 114a of the hand portion 114 where the first pads 140 are not to be placed. A plurality of pedestals 114c are provided corresponding to the plurality of first installation portions 1161, and the pedestals 114c are processed to have a common flat surface so that the upper surfaces of the plurality of pedestals 114c are positioned on the same plane.

[0019] Correspondingly, first pad 140 has a hollow shape and includes a first extending portion 141 extending from large diameter portion 1161a of first installation portion 1161, a first engaging portion 142 engaging with small diameter portion 1161b of first installation portion 1161, a first extending portion 144 extending from first engaging portion 142, and a first through-hole (first inlet portion 149 described below) communicating with first air passage 120. First engaging portion 142 has a substantially cylindrical shape extending along center line CL1 and includes an upper surface 142a, a lower surface 142b, an outer circumferential surface 142c, and an inner circumferential surface 142d. The first extension portion 144 has an annular structure centered on the center line CL1 and includes a first base end 144a located radially inward and continuous with the first engagement portion 142, a first tip end 144b located above and radially outward from the first base end 144a, and a first jaw 144c located between the first base end 144a and the first tip end 144b and radially outward from the first engagement portion 142. The first extension portion 141 extends outward from the outer circumferential surface 142c of the first engagement portion 142, i.e., the radial dimension of the first extension portion 141 is greater than the radial dimension of the first engagement portion 142. Therefore, the first extension portion 141 and the first jaw 144c of the first extension portion 144 form an annular recessed structure outside the outer circumferential surface 142c of the first engagement portion 142.

[0020] As a result, when the first pad 140 is provided on the first installation portion 1161, the first extension portion 141 of the first pad 140 is provided on the large diameter portion 1161a of the first installation portion 1161, and is provided so that the upper surface 141a of the first extension portion 141 abuts against the connecting portion 1161c of the first installation portion 1161. Furthermore, the first engagement portion 142 of the first pad 140 is provided on the small diameter portion 1161b of the first installation portion 1161, and is provided so that the outer peripheral surface 142c of the first engagement portion 142 abuts against the inner surface of the small diameter portion 1161b of the first installation portion 1161. The first extending portion 144 of the first pad 140 is placed on the upper surface of the small diameter portion 1161b of the first installation portion 1161 (i.e., the upper surface 114a of the hand portion 114 of the hand body 110), and the first jaw portion 144c of the first extending portion 144 is placed so as to abut the upper surface of the small diameter portion 1161b. Therefore, the first engaging portion 142 of the first pad 140 defines the radial position and the height position of the first pad 140 by engaging with the small diameter portion 1161b so that the first jaw portion 144c of the first extending portion 144 and the upper surface 141a of the first extending portion 141 sandwich the small diameter portion 1161b of the first installation portion 1161. That is, the small diameter portion 1161b of the first mounting portion 1161 is inserted into the annular recessed portion formed between the first extension portion 141 and the first jaw portion 144c of the first extension portion 144. As an example, at least the first extension portion 141 of the first pad 140 is made of a flexible material and configured to be deformable. The first extension portion 141 passes through the small diameter portion 1161b of the first mounting portion 1161 in a deformed state, and when it reaches the large diameter portion 1161a of the first mounting portion 1161, the deformation is released. In this way, the first pad 140 is attached to the first mounting portion 1161.

[0021] 5 to 7, the first pad 140 of this embodiment has a first suction surface 146 formed by a plane defined by the upper edge of the first tip portion 144b. The first pad 140 has a first extension portion 141, a first engagement portion 142, a first extension portion 144, the first suction surface 146, and a first suction space 148 defined by the upper surface 142a of the first engagement portion 142. The first pad 140 sucks air from the first suction space 148 to adsorb the transported object W. The first pad 140 also has a first inlet portion 149 defined by the inner circumferential surface 142d of the first engagement portion 142 in the center of the first engagement portion 142. That is, the first engagement portion 142 has a substantially cylindrical shape, and the first inlet portion 149 can also be referred to as a first through hole. The first inlet portion 149 connects the first suction space 148 to the first air passage 120. Therefore, air in the first suction space 148 flows into the first air passage 120 via the first inlet portion 149 and is exhausted from a vacuum source V connected to the first air passage 120. The first extension portion 144 extends radially outward from the first engagement portion 142 in a direction away from the first installation portion 1161 of the hand body 110 (a direction away from the upper surface 114a of the hand unit 114 of the hand body 110). As shown in FIG. 6 , the area S1 of the first suction surface 146 is larger than the area S2 of the first inlet portion 149. The area S2 of the first inlet portion 149 is a cross-sectional area of ​​a plane perpendicular to the extension direction of the first inlet portion 149 and can also be expressed as a cross-sectional area of ​​a plane perpendicular to the air flow direction (flow path cross-sectional area).

[0022] The structure around the second pad 150 of the hand 100 will be described with reference to Figures 1, 5, 6, and 8. The hand body 110 has a plurality of second mounting portions 1162 on which the second pads 150 are mounted. The second mounting portions 1162 are provided on the hand unit 114 corresponding to the positions where the second pads 150 are mounted. The second pads 150 are mounted on the hand unit 114 of the hand body 110 by the second mounting portions 1162. The second mounting portions 1162 form mounting openings in the upper surface 114a of the hand unit 114, into which the second pads 150 are inserted. The second mounting portions 1162 connect the upper surface 114a of the hand unit 114 to the second ventilation path 130. The second mounting portion 1162 for mounting the second pad 150 has a large diameter portion 1162a, a small diameter portion 1162b, and a connecting portion 1162c, similar to the first mounting portion 1161 for mounting the first pad 140 described above. The small diameter portion 1162b is a base for mounting the second pad 150 and fits into an annular recess structure (described below) formed on the outside of the outer circumferential surface 152c of the second engaging portion 152 of the second pad 150. The large diameter portion 1162a is provided below the small diameter portion 1162b and forms a partitioned space on the inner surface of the large diameter portion 1162a, which communicates with the second air passage 130. It can also be said that the space partitioned on the inner surface of the large diameter portion 1162a forms part of the second communication portion 134 of the second air passage 130. As an example, a groove 114d is formed in the lower surface 114b of the hand unit 114 below the large diameter portion 1162a, and the groove 114d forms a part of the second communication portion 134 of the second air passage 130 and is covered by the lid 115. That is, at least a part of the second communication portion 134 of the second air passage 130 is formed by the groove 114d in the lower surface 114b of the hand unit 114 and the lid 115. Furthermore, the connection portion 1162c is a step between the large diameter portion 1162a and the small diameter portion 1162b, and serves as a limiting structure for limiting the position of the second pad 150 after attachment to the second installation portion 1162. As an example, the base portion 114c of the hand unit 114 has a hole formed therein that forms an attachment opening through which the second pad 150 is inserted, and is disposed above the small diameter portion 1162b. The second pad 150 is attached to the second installation portion 1162 so as to rest on the base portion 114c.Furthermore, because the inner diameter of the hole in the pedestal portion 114c is equal to the inner diameter of the small-diameter portion 1162b, the pedestal portion 114c can also be considered a part of the small-diameter portion 1162b. The pedestal portion 114c is formed by using end milling to dig out portions of the upper surface 114a of the hand portion 114 where the second pads 150 are not to be placed. A plurality of pedestals 114c are provided corresponding to the plurality of second installation portions 1162, and the pedestals 114c are processed to have a common flat surface so that the upper surfaces of the plurality of pedestals 114c are located on the same plane. Furthermore, the upper surfaces of the pedestals 114c provided corresponding to the second installation portions 1162 and the upper surfaces of the pedestals 114c provided corresponding to the first installation portions 1161 are located on the same plane.

[0023] Correspondingly, the second pad 150 has a hollow shape and includes a second extension portion 151 extending from the large diameter portion 1162a of the second installation portion 1162, a second engagement portion 152 engaging with the small diameter portion 1162b of the second installation portion 1162, a second extension portion 154 extending from the second engagement portion 152, and a second through-hole (a second inlet portion 159 described below) communicating with the second air passage 130. The second engagement portion 152 has a substantially cylindrical shape extending along the center line CL2 and includes an upper surface 152a, a lower surface 152b, an outer circumferential surface 152c, and an inner circumferential surface 152d. The second extension portion 154 has an annular structure centered on the center line CL2 and includes a second base end 154a located radially inward and continuous with the second engagement portion 152, a second tip end 154b located above and radially outward from the second base end 154a, and a second jaw 154c located between the second base end 154a and the second tip end 154b and radially outward from the second engagement portion 152. The second extension portion 151 extends outward from the outer circumferential surface 152c of the second engagement portion 152, i.e., the radial dimension of the second extension portion 151 is greater than the radial dimension of the second engagement portion 152. Therefore, the second extension portion 151 and the second jaw 154c of the second extension portion 154 form an annular recessed structure outside the outer circumferential surface 152c of the second engagement portion 152.

[0024] As a result, when the second pad 150 is provided on the second installation portion 1162, the second extension portion 151 of the second pad 150 is provided on the large diameter portion 1162a of the second installation portion 1162, and is provided so that the upper surface 151a of the second extension portion 151 abuts against the connecting portion 1162c of the second installation portion 1162. In addition, the second engagement portion 152 of the second pad 150 is provided on the small diameter portion 1162b of the second installation portion 1162, and is provided so that the outer peripheral surface 152c of the second engagement portion 152 abuts against the inner surface of the small diameter portion 1162b of the second installation portion 1162. The second extending portion 154 of the second pad 150 is placed on the upper surface of the small diameter portion 1162b of the second installation portion 1162 (i.e., the upper surface 114a of the hand portion 114 of the hand body 110), and the second jaw portion 154c of the second extending portion 154 is placed so as to abut the upper surface of the small diameter portion 1162b. Therefore, the second engaging portion 152 of the second pad 150 defines the radial position and the height position of the second pad 150 by engaging with the small diameter portion 1162b so that the second jaw portion 154c of the second extending portion 154 and the upper surface 151a of the second extending portion 151 sandwich the small diameter portion 1162b of the second installation portion 1162. That is, the small diameter portion 1162b of the second mounting portion 1162 is inserted into the annular recessed portion formed between the second extension portion 151 and the second jaw portion 154c of the second extension portion 154. As an example, at least the second extension portion 151 of the second pad 150 is made of a flexible material and configured to be deformable. The second extension portion 151 passes through the small diameter portion 1162b of the second mounting portion 1162 in a deformed state, and when it reaches the large diameter portion 1162a of the second mounting portion 1162, the deformation is released. In this way, the second pad 150 is attached to the second mounting portion 1162.

[0025] 5, 6, and 8, the second pad 150 of this embodiment has a second suction surface 156 formed by a plane defined by the upper edge of the second tip portion 154b. The second pad 150 has a second suction space 158 defined by the second extension portion 151, the second engagement portion 152, the second extension portion 154, the second suction surface 156, and the upper surface 152a of the second engagement portion 152. The second pad 150 sucks air from the second suction space 158 to suck the transported object W. The second pad 150 also has a second inlet portion 159 defined by the inner circumferential surface 152d of the second engagement portion 152 in the center of the second engagement portion 152. That is, the second engagement portion 152 has a substantially cylindrical shape, and the second inlet portion 159 can also be referred to as a second through hole. The second inlet portion 159 connects the second suction space 158 to the second air passage 130. Therefore, air in the second suction space 158 flows into the second air passage 130 via the second inlet portion 159 and is exhausted from the vacuum source V connected to the second air passage 130. The second extension portion 154 extends radially outward from the second engagement portion 152 in a direction away from the second installation portion 1162 of the hand body 110 (a direction away from the upper surface 114a of the hand unit 114 of the hand body 110). As shown in FIG. 6 , the area S3 of the second suction surface 156 is larger than the area S4 of the second inlet portion 159. The area S4 of the second inlet portion 159 is a cross-sectional area of ​​a plane perpendicular to the extension direction of the second inlet portion 159 and can also be expressed as a cross-sectional area of ​​a plane perpendicular to the air flow direction (flow path cross-sectional area).

[0026] More specifically, in this embodiment, two types of pads with different suction volumes are used to suck and hold the transported object W. Of these, the first pad 140 has a smaller suction volume than the second pad 150. As an example, as shown in FIGS. 5 and 6 , the first pad 140 has a first inlet 149 (first through hole) in the center of the first engagement portion 142, and the second pad 150 has a second inlet 159 (second through hole) in the center of the second engagement portion 152. Furthermore, the area S2 of the first inlet 149 (first through hole) is smaller than the area S4 of the second inlet 159 (second through hole). Therefore, the amount of air flowing into the first inlet 149 per unit time is smaller than that of the second inlet 159. Therefore, the suction volume of the first pad 140 can be limited to be smaller than that of the second pad 150. As an example, the thickness (radial width) of the first engagement portion 142 of the first pad 140 may be made larger than the thickness (radial width) of the second engagement portion 152 of the second pad 150 so that the area S2 of the first inlet portion 149 is smaller than the area S4 of the second inlet portion 159.

[0027] As an example, in another embodiment shown in FIG. 9, the suction amount of the first pad 140A is limited to be less than the suction amount of the second pad 150 by a means different from that of the embodiment shown in FIGS. 5 to 7. As shown in FIG. 9, the hand 100 further includes a throttle member 160 that is inserted into a first inlet portion 149 (first through hole) formed in the center of the first engagement portion 142 of the first pad 140A. The throttle member 160 has a hollow shape with a through hole 162 and limits the suction amount of the first pad 140A to be less than the suction amount of the second pad 150. The throttle member 160 is inserted into the first inlet portion 149 and engages with the inner circumferential surface 142d of the first engagement portion 142, thereby defining its radial position. Furthermore, the first pad 140A has a first contact portion 143 extending inward from the inner peripheral surface 142d of the first engagement portion 142, and the lower surface 160a of the throttle member 160 engages with the upper surface 143a of the first contact portion 143 of the first pad 140A, thereby defining the heightwise position of the throttle member 160. Therefore, the area of ​​the first inlet portion 149 of the first pad 140A is reduced to the area of ​​the through-hole 162 of the throttle member 160. This makes it possible to limit the suction volume of the first pad 140A to be smaller than that of the second pad 150. As a result, the first pad 140A sucks and holds the transported object W with a small suction volume, and the second pad 150 attracts the transported object W with a large suction volume.

[0028] 5, in this embodiment, the height H2 of the second pad 150 is equal to or greater than the height H1 of the first pad 140. Preferably, the height H2 of the second pad 150 is greater than the height H1 of the first pad 140. The height H1 of the first pad 140 is the vertical distance from the upper surface 114a of the hand portion 114 of the hand body 110 (or the upper surface of the base 114c if the base 114c is present) to the upper end of the first tip 144b. Alternatively, the height H1 of the first pad 140 indicates the position (separated position) at which the first tip 144b is spaced from the upper surface 114a of the hand portion 114 of the hand body 110. Similarly, the height H2 of the second pad 150 is the vertical distance from the upper surface 114a of the hand portion 114 of the hand body 110 (or the upper surface of the base 114c if the base 114c is present) to the upper end of the second tip 144b. In other words, the height H2 of the second pad 150 indicates the position (separated position) where the second tip portion 154b is separated from the upper surface 114a of the hand portion 114 of the hand main body 110. That is, the upper end of the second tip portion 154b of the second pad 150 is located at a position farther away from the upper surface 114a of the hand portion 114 of the hand main body 110 than the upper end of the first tip portion 144b of the first pad 140. In other words, the second suction surface 156 of the second pad 150 is located at a position farther away from the upper surface 114a of the hand portion 114 of the hand main body 110 than the first suction surface 146 of the first pad 140.

[0029] In addition, the second extension portion 154 of the second pad 150 is configured to be displaceable between a first position P1 where the end of the second extension portion 154 (i.e., the upper end of the second tip portion 154b) is farther from the upper surface 114a of the hand portion 114 of the hand main body 110 than the end of the first extension portion 144 (i.e., the upper end of the first tip portion 144b), and a second position P2 (shown by the dashed line in Figure 5) where the end of the first extension portion 144 is closer to the upper surface 114a of the hand portion 114 of the hand main body 110 than the end of the first extension portion 144. As a result, the second pad 150 can be displaced between a first position P1 in a normal state where the second pad 150 is farther away from the upper surface 114a of the hand unit 114 of the hand main body 110 than the height H1 of the first pad 140, and a second position P2 in a state where the second pad 150 is equal to or less than the height H1 of the first pad 140 and closer to the upper surface 114a of the hand unit 114 of the hand main body 110 than the first position P1 when transporting the transported object W. The normal state of the second pad 150 refers to a state in which the second pad 150 is not affected by the transported object W. In other words, the normal state of the second pad 150 refers to a state in which the second pad 150 is not deformed or displaced due to suction and / or adsorption of the transported object W or the weight of the transported object W supported and / or adsorbed by the second pad 150.

[0030] 1 to 5, when the hand 100 transports the load W, the transport robot 21 of the transport device 20 shown in FIG. 3 moves the hand body 110 of the hand 100 to below the load W, and then drives the vacuum source V. When the vacuum source V is driven, air in the first suction space 148 of the first pad 140 flows into the first air passage 120 via the first inlet 149. At this time, a suction force is generated in the first pad 140. Similarly, when the vacuum source V is driven, air in the second suction space 158 of the second pad 150 flows into the second air passage 130 via the second inlet 159. At this time, a suction force is generated in the second pad 150 (the suction timing of the first pad 140 and the second pad 150 will be described later). Therefore, the second pad 150, at a position (e.g., first position P1) below the transported object W and higher than the first pad 140, applies suction to the transported object W with a greater suction force than the first pad 140. When the second suction surface 156 of the second pad 150 is in contact with the transported object W, the height of the second pad 150 is displaced to a position close to the first pad 140 (e.g., height H1 of the first suction surface 146 of the first pad 140) due to the air in the second suction space 158 being sucked in by the vacuum source V and / or the weight of the transported object W supported by the second pad 150. Furthermore, when the second pad 150 draws the transported object W to a position close to the first pad 140, the first suction surface 146 of the first pad 140 comes into contact with the transported object W, and the first pad 140 suction-holds the transported object W. The second pad 150 is displaced to a position equal to the height of the first pad 140 (no warpage) or to a position lower than the first pad 140 (downward warpage) depending on the warpage of the transported object W. Of course, the second pad 150 may be positioned higher than the first pad 140 relative to the warpage of the transported object W (for example, between the first position P1 and the height position of the first pad 140), or may not be in contact with the second suction surface 156 of the second pad 150 relative to the warpage of the transported object W (upward warpage).

[0031] Referring to FIG. 1 , in this embodiment, four first pads 140 are arranged on the same circumference of the hand body 110, and three second pads 150 are arranged on the same circumference of the hand body 110. Specifically, four first pads 140 are arranged on the circumference of an imaginary circle C1 whose center is a reference point P. Similarly, three second pads 150 are arranged on the circumference of an imaginary circle C2 whose center is also a reference point P. The reference point P is an imaginary point that can be adjusted depending on the structure of the hand body 110. For example, the reference point P is located on a center line L extending along the extension direction of the hand body 110 (i.e., the left-right direction in the drawing). The center line L is a line that bisects the hand body 110 (hand portion 114) in the width direction of the hand body 110 (i.e., the up-down direction in the drawing). The multiple first pads 140 are arranged on the same circumference about a reference point P located on a center line L extending along the extension direction of the hand body 110 (i.e., the left-right direction in the drawing), and adsorb the circular transported object W so that the center of the circular transported object W corresponds to the reference point P. Similarly, the multiple second pads 150 are arranged on the same circumference about a reference point P located on a center line L extending along the extension direction of the hand body 110 (i.e., the left-right direction in the drawing), and adsorb the circular transported object W so that the center of the circular transported object W corresponds to the reference point P.

[0032] Furthermore, it is preferable that the centers (reference point P) of the imaginary circle C1 for placing the first pad 140 and the imaginary circle C2 for placing the second pad 150 coincide with each other, as shown in FIG. 1 . However, the centers of the imaginary circle C1 and the imaginary circle C2 do not necessarily have to coincide with each other. That is, the imaginary circle C1 and the imaginary circle C2 may each have a reference point P set at a different position as their centers. Furthermore, the multiple first pads 140 are connected to each other via the first communication portion 124 of the first ventilation path 120. As an example, the first communication portion 124 is provided in the hand unit 114 along the installation direction of the circumference of the imaginary circle C1, and connects the multiple first pads 140 to the first ventilation portion 122 provided in the base 112. However, multiple first communication portions 124 may be provided, each connecting the first pad 140 to the first ventilation portion 122. Similarly, the multiple second pads 150 are each connected to each other by the second connecting portion 134 of the second ventilation path 130. As an example, the second connecting portion 134 is provided in the hand unit 114 along the installation direction of the circumference of the imaginary circle C2, connecting the multiple second pads 150 and then connecting to the second ventilation portion 132 provided in the base unit 112, but multiple second connecting portions 134 may be provided, each connecting the second pad 150 to the second ventilation portion 132.

[0033] In this embodiment, a reference point P as the center of the first pad 140 and the second pad 150 is located on the center line L of the hand main body 110, and the load W is adsorbed to the first pad 140 or sucked to the second pad 150 so that the center of the load W corresponds to the center of the first pad 140 and the second pad 150 (i.e., the reference point P). Therefore, the weight of the load W is distributed to the first pad 140 and the second pad 150 around the reference point P. As shown in FIG. 1 , when four first pads 140 are arranged on the circumference of an imaginary circle C1, the four first pads 140 are provided on the hand main body 110, two on each side, symmetrically on the left and right sides with respect to the center line L of the hand main body 110, and uniform suction force is applied to the circular load W, allowing the load W to be stably adsorbed. Similarly, as shown in Figure 1, when three second pads 150 are arranged on the circumference of the imaginary circle C2, the three second pads 150 are provided on the hand body 110, one on each side, symmetrically with respect to the center line L of the hand body 110, and one along the center line L, so that they can apply an even suction force to the circular transported object W and attract the transported object W stably.

[0034] 1 , the diameter of the imaginary circle C1 on which the first pad 140 is disposed is different from the diameter of the imaginary circle C2 on which the second pad 150 is disposed. As an example, the hand body 110 has an inner side closer to a reference point P located on a center line L extending along the extension direction of the hand body 110 (i.e., the left-right direction in the drawing) and an outer side farther from the reference point P, and the second pad 150 is provided on the hand body 110 more inward than the first pad 140. That is, with respect to the imaginary circles C1 and C2 centered on the common reference point P, the imaginary circle C2, whose circumference includes the second pad 150, has a smaller diameter than the imaginary circle C1, whose circumference includes the first pad 140, and the circumference of the imaginary circle C2 is closer to the reference point P than the circumference of the imaginary circle C1. The second pad 150 sucks the center side of the transported object W, which is close to the center of the transported object W and tends to have a smaller amount of warping, thereby avoiding the phenomenon where the second suction surface 156 of the second pad 150 and the transported object W come out of contact with each other.

[0035] In this embodiment, the first air passage 120 and the second air passage 130 are formed at different positions on the hand body 110 so as not to communicate with each other. Not communicating with each other means that air does not flow between the first air passage 120 and the second air passage 130 formed on the hand body 110. In other words, the first air passage 120 communicating with the first pad 140 and the second air passage 130 communicating with the second pad 150 form independent suction systems. That is, the first air passage 120 and the second air passage 130 are each connected to a vacuum source V, which can operate air suction for the first pad 140 and the second pad 150, respectively.

[0036] In this embodiment, the first air passage 120 and the second air passage 130 are formed at different positions on the hand body 110 so as not to overlap each other in a plan view. "Not overlapping" can also be rephrased as meaning that the first air passage 120 and the second air passage 130 do not have an overlapping section in a plan view (thickness direction of the hand body 110). As described above, the first pad 140, which is placed along the circumference of the imaginary circle C1, is provided further outward on the hand body 110 than the second pad 150, which is placed along the circumference of the imaginary circle C2. Therefore, the first air passage 120 is formed outside the second air passage 130. That is, the first communication portion 124 communicating with the first pad 140 is located outside the second communication portion 134 communicating with the second pad 150 in the hand portion 114, and the first ventilation portion 122 connected to the first communication portion 124 is located outside the second ventilation portion 132 connected to the second communication portion 134 in the base portion 112. In this way, the entire first ventilation path 120 is located outside the entire second ventilation path 130 in the hand main body 110, and the first connection hole 126 connected to the vacuum source V of the first ventilation path 120 and the second connection hole 136 connected to the vacuum source V of the second ventilation path 130 are located at different positions in the hand main body 110. Because the first air passage 120 and the second air passage 130 do not overlap in the thickness direction of the hand body 110, it is possible to reduce the thickness of the hand body 110, even though two independent suction systems are formed in the hand body 110. In another embodiment (not shown), the first air passage 120 and the second air passage 130 may be formed at different positions in the hand body 110 so as not to overlap each other in side view (for example, the first air passage 120 and the second air passage 130 may be formed at different depth positions in the hand body 110), thereby forming suction systems that do not communicate with each other (independent).

[0037] Next, a transfer device 20 including the above-described hand 100 will be described with reference to FIGS. 1 to 5 and 10 . As an example, in this embodiment, the transfer device 20 is used as an EFEM (Equipment Front End Module), and, as shown in FIG. 3 , includes a plurality of load ports 50 for opening and closing doors of a container H (e.g., a FOUP) that accommodates a transfer object W. The transfer device 20 transfers the transfer object W between the container H and a processing device 60 that processes the transfer object W. The transfer device 20 includes the above-described hand 100, a transfer robot 21 that freely moves the hand 100, a moving body 22, a guide structure 23, and a housing 24. The hand 100 is attached to a robot arm 211 of the transfer robot 21. The transfer robot 21 is provided on the moving body 22. The guide structure 23 guides the movement of the moving body 22. The housing 24 houses the transport robot 21, the moving body 22, and the guide structure 23. As a result, the moving body 22 is attached to the guide structure 23 (for example, a slide rail structure, a conveyor drive device, etc.) and is installed so as to be able to move freely within the housing 24 by the guide structure 23. Therefore, the transport robot 21 installed on the moving body 22 can move freely within the housing 24.

[0038] 1, 3, and 4, the transport device 20 also includes a switching unit 25. The switching unit 25 is provided, for example, in the transport robot 21 and switches the communication state of the first air passage 120 and the second air passage 130. The transport device 20 also includes a control unit 26. The control unit 26 is provided, for example, in the housing 24 and controls the operation of the transport robot 21, the movement of the moving body 22, and the operation of the switching unit 25. As a result, the transport robot 21, to which the hand 100 is attached, operates within the housing 24 together with the moving body 22, which moves along the guide structure 23 within the housing 24 under the control of the control unit 26, and transports the transported object W to the load port 50 or the processing device 60. The first pad 140 and the second pad 150 can suck and hold the transported object W depending on the result of switching the communication state of the first air passage 120 and / or the second air passage 130 by the switching unit 25, which is operable under the control of the control unit 26.

[0039] 3 and 4, in this embodiment, the transport robot 21 includes a robot arm 211 to which the hand 100 is attached, a main body 212a, a drive unit 212b provided inside the main body 212a, a connection unit 213, and a suction path 214. The robot arm 211 is, for example, a horizontal articulated arm formed by connecting multiple arm members, and is configured to be rotatable within a horizontal plane and to be movable up and down by an elevation mechanism (not shown) included in the drive unit 212b. The hand 100 is attached to the tip of an arm member of the robot arm 211, as shown in FIG. 10. The transport robot 21 operates within the housing 24 in conjunction with the movement of the movable body 22. Therefore, the transport robot 21 moves via the movable body 22 to the vicinity of the load W to be transported, and the hand 100 attached to the robot arm 211 can be inserted below the load W by the movement of the robot arm 211 itself (rotating or elevating the arm member). The driving unit 212 b is, for example, a motor or a transmission mechanism, and applies a driving force to the robot arm 211 .

[0040] 4 , the connection portion 213 includes a first connection path 213a communicating with the first air passage 120 and a second connection path 213b communicating with the second air passage 130. The first connection path 213a connects the first air passage 120 to a vacuum source V provided in the transport device 20. The second connection path 213b connects the second air passage 130 to the vacuum source V provided in the transport device 20. One end of the suction path 214 connects to the first connection path 213a and the second connection path 213b, and the other end is connected to the vacuum source V. That is, the first air passage 120 and the second air passage 130 of the hand 100 communicate with the suction path 214 via the first connection path 213a and the second connection path 213b of the transport device 20, respectively, and are also connected to the vacuum source V via the suction path 214. Furthermore, the vacuum source V does not necessarily have to be provided in the transfer device 20, and may be separate from the transfer device 20. Alternatively, the vacuum source V may form a central vacuum system that communicates with a plurality of vacuum units. Since the vacuum source V that forms the central vacuum system is always on, the operation of turning on the vacuum source V, which will be described later, is performed, for example, by operating a solenoid valve (not shown) provided in the suction path 214.

[0041] In the present embodiment, the switching unit 25 can switch the communication state of each of the first air passage 120 and the second air passage 130 between a suction state in which air suction force is applied by the vacuum source V and a blocked state in which air suction force is not applied by the vacuum source V. As shown in Fig. 4, the switching unit 25 includes a first switching unit 251a that switches the communication state of the first air passage 120 and a second switching unit 251b that switches the communication state of the second air passage 130. The first switching unit 251a and the second switching unit 251b are, for example, solenoid valves and are located at one end of the first air passage 120 and the second air passage 130, respectively. That is, the first switching unit 251a is installed between the first air passage 120 and the suction passage 214, and indirectly switches the communication state of the first air passage 120 by switching the communication state of the first connection passage 213a that communicates with the first air passage 120. Similarly, the second switching unit 251b is installed between the second air passage 130 and the suction passage 214, and indirectly switches the communication state of the second air passage 130 by switching the communication state of the second connection passage 213b that communicates with the second air passage 130. In this way, the communication state of the first air passage 120 can be independently switched by the first switching unit 251a. Furthermore, the communication state of the second air passage 130 can be independently switched by the second switching unit 251b. That is, the operation of transitioning the communication state of the first air passage 120 to an suction state or a blocked state and the operation of transitioning the communication state of the second air passage 130 to an suction state or a blocked state may be performed simultaneously or at different times as necessary.

[0042] Specifically, for example, when the switching unit 25 receives a signal from the control unit 26, it switches the communication state of the first air passage 120 and / or the second air passage 130 to a blocked state, and when it does not receive a signal from the control unit 26, it switches the communication state of the first air passage 120 and / or the second air passage 130 to a suction state. When the communication state of the first air passage 120 is blocked, the first pad 140 communicating with the first air passage 120 does not suck air. Similarly, when the communication state of the second air passage 130 is blocked, the second pad 150 communicating with the second air passage 130 does not suck air. Note that if the switching unit 25 switches the communication state of the first air passage 120 to a blocked state when the first pad 140 is already adsorbing the transported object W, adsorption continues unless air flows in (i.e., the holding pressure (vacuum pressure) does not change). When the communication state of the first air passage 120 is the suction state, the first pad 140 in communication with the first air passage 120 sucks in air. Similarly, when the communication state of the second air passage 130 is the suction state, the second pad 150 in communication with the second air passage 130 sucks in air.

[0043] 11 , the switching unit 25 further includes a first connection terminal 252a and a second connection terminal 252b, a first control connector 253a and a second control connector 253b, and a first power connector 254a and a second power connector 254b. The first connection terminal 252a connects the first air passage 120 of the hand 100 to the first connection passage 213a. The solenoid valve serving as the first switching unit 251a can switch the communication state of the first connection passage 213a connected to the first connection terminal 252a. The second connection terminal 252b connects the second air passage 130 of the hand 100 to the second connection passage 213b. The solenoid valve serving as the second switching unit 251b can switch the communication state of the second connection passage 213b connected to the second connection terminal 252b. The first control connector 253a and the second control connector 253b are connected to a harness or the like that enables communication with the control unit 26 provided in the transport device 20. The first power connector 254a and the second power connector 254b are connected to a power cable or the like that supplies power from a power source (not shown) to the solenoid valve, the motor of the drive unit 212b, etc. The above-mentioned components of the switching unit 25 are modularized and provided on the main body wall 212c of the main body 212a of the transport robot 21.

[0044] 4 and 11 , the transfer robot 21 of the transfer device 20 further includes a pressure measurement unit 215. The pressure measurement unit 215 is, for example, a vacuum gauge provided in each of the first connection path 213a and the second connection path 213b, and measures the pressure values ​​of the first air passage 120 and the second air passage 130. The control unit 26 is electrically connected to the pressure measurement unit 215 and can control the switching unit 25 (the first switching unit 251a or the second switching unit 251b) based on the measurement results of the pressure measurement unit 215. As an example, the pressure measurement unit 215 measures the pressure value of the first air passage 120 before starting the transfer of the transferred object W. The control unit 26 controls the second switching unit 251b to switch the second air passage 130 to a shut-off state before starting the transfer of the transferred object W. Furthermore, when the pressure value of the first air passage 120 measured by the pressure measurement unit 215 is equal to or lower than a predetermined value, the control unit 26 controls the second switching unit 251b to transition the second air passage 130 to a suction state (details will be described later in the section on the method for transporting the transported object W). This allows the second pad 150, which has a greater suction force than the first pad 140, to attract the transported object W toward the first pad 140 and the second pad 150. The pressure measurement unit 215 may also be capable of measuring the pressure value of the second air passage 130 in addition to the pressure value of the first air passage 120. This means that the control of the first switching unit 251a or the second switching unit 251b by the control unit 26 is not necessarily based on the pressure value of the first air passage 120, and may be adjusted as needed. However, the pressure measurement unit 215 may be provided in the first connection path 213a or the suction path 214 to measure only the pressure value of the first air passage 120.

[0045] As can be seen from this, the hand 100 of this embodiment and the transport device 20 to which the hand 100 is attached include a first pad 140 communicating with the first air passage 120 and a second pad 150 communicating with the second air passage 130. The second pad 150 has a larger air suction volume per unit time than the first pad 140. Therefore, the second pad 150 has a larger force pulling the transported object W toward the hand 100 than the first pad 140. On the other hand, when the second pad 150 suctions and holds the transported object W, if a gap occurs between the second suction surface 156 and the transported object W, the amount of air that flows in through the gap is proportional to the larger suction volume. In contrast, the first pad 140 has a smaller air suction volume per unit time than the second pad 150. Therefore, the first pad 140 has a smaller force pulling the transported object W toward the hand 100 than the second pad 150. On the other hand, when the first pad 140 suction-holds the transported object W and there is a gap between the first suction surface 146 and the transported object W, the amount of air that flows in through the gap is small in proportion to the small suction volume. Due to the difference in characteristics described above, the second pad 150 is advantageous for attracting the transported object W and bringing it into close contact with the first pad 140 and the second pad 150, while the first pad 140 is advantageous for stably suction-holding the transported object W. Note that the holding force of the transported object W by the hand 100 depends on the total area of ​​the suction surfaces of the suction pads, assuming the performance (vacuum attainment level) of the vacuum source V is the same. In this embodiment, the holding force required for transporting the transported object W is ensured by ensuring a sufficient area of ​​the first suction surface 146 for stable suction-holding. Therefore, to prevent the inflow of air from the second pad 150 from affecting the adsorption and holding of the transported object W by the first pad 140, the transported object W can be adsorbed and held by the first pad 140 alone, even when the suction amount (suction force) of the second pad 150 is set to 0 (the second air passage 130 is blocked).

[0046] According to this embodiment, even if any of the multiple first pads 140 loses contact with the transported object W due to warping of the transported object W, the suction volume of the first pad 140 during suction is small, and therefore, the amount of air that flows in through the gap between the transported object W and the non-contacting first pad 140 is small. This prevents a decrease in the holding force for suction-holding the transported object W. The number of first pads 140, the area of ​​the first suction surface 146, and the suction volume (area S2 of the first inlet 149) are set so that sufficient holding force for transporting the transported object W can be generated even if any number of first pads 140 lose contact with the transported object W. Furthermore, even if any of the multiple second pads 150 loses contact with the transported object W due to warping of the transported object W, the suction volume of the non-contacting second pad 150 during suction is zero. Therefore, no air flows in through the gap between the transported object W and the non-contacting second pad 150. This prevents a decrease in the holding force of the first pad 140 for suction-holding the transported object W. As a result, the hand 100 of this embodiment and the conveying device 20 to which the hand 100 is attached can reliably adsorb and hold the transported object W even if the transported object W warps, while suppressing the inflow of air through the gap between the non-contact pad and the transported object W, and ensuring sufficient suction force of the pad.

[0047] The method of transporting the transported object W by the transport device 20 equipped with the hand 100 of this embodiment will be described below using two examples.

[0048] 1 to 5 and 11 and 12, a method for transporting a transported object W using the transport device 20 including the hand 100 according to the first embodiment will be described step by step. The method for transporting a transported object W is a method for transporting a transported object W using the transport device 20 including the hand 100 that holds the transported object W, and mainly includes a starting step S11, a suction step S12, a blocking step S13, a determining step S14, a transporting step S15, and a checking step S16. In the starting step S11, a preliminary operation for suctioning the transported object W is started. In the suction step S12, the first air passage 120 communicating with the first pad 140 and the second air passage 130 communicating with the second pad 150 are switched to a suction state, and the transported object W is sucked by the first pad 140 communicating with the first air passage 120 and the second pad 150 communicating with the second air passage 130. In the blocking step S13, after the transported object W is sucked and held, the second air passage 130 communicating with the second pad 150 is switched to a blocked state. If it is determined in the determination step S14 that the pressure value of the first air passage 120 exceeds a predetermined value, the process proceeds to the transport step S15. If it is determined that the pressure value of the first air passage 120 is equal to or lower than the predetermined value, the process proceeds again to the suction step S12. In the transport step S15, the transported object W is transported to a predetermined position. In the confirmation step S16, it is confirmed whether to continue transporting the transported object W. If there is an object W to be transported, the process proceeds again to the start step S11. If there is no object W to be transported, the transport of the object W is terminated. According to this transport method, the transport device 20 equipped with the hand 100 can transport the transported object W from a slot in a container H or a mounting table of a processing device 60 to another location while the hand 100 sucks and holds the transported object W. The determination step S14 and the confirmation step S16 may be omitted.

[0049] Specifically, in this embodiment, the start step S11 includes a vacuum source driving step S111 and a transfer robot moving step S112. First, in the vacuum source driving step S111, when starting the transfer of the transfer object W, the transfer device 20 receives, for example, a suction start signal and turns on the vacuum source V. The vacuum source V remains on at all times until the transfer of the transfer object W is completed (for example, until the transfer completion signal is received), and the communication state between the first air passage 120 and the second air passage 130 is switched by the switching unit 25. Next, in the transfer robot moving step S112, when the transfer device 20 receives, for example, a movement start signal, the transfer device 20 controls the operation of the guide structure 23 and the robot arm 211 to move the transfer robot 21 so that the hand 100 of the transfer robot 21 is positioned below the transfer object W. During this movement, the transport device 20 turns off the first switching unit 251a and the second switching unit 251b, switches the first air passage 120 and the second air passage 130 to a blocked state, and sets the suction amount (suction force) of the first pad 140 and the second pad 150 to zero. This prevents the transported object W from being sucked in an unexpected position. When the hand 100 is inserted below the transported object W in the transport robot movement step S112, the preliminary work for sucking the transported object W is completed, and the process proceeds to the suction step S12.

[0050] Next, after inserting the hand 100 below the transported object W in the transport robot moving step S112, the transport device 20 receives, for example, a holding start signal and drives the switching unit 25 to change the communication state in the suction step S12. More specifically, in the suction step S12, the transport device 20 turns on, for example, the first switching unit 251a and the second switching unit 251b to transition the first air passage 120 and the second air passage 130 to a suction state, and sucks the transported object W using the first pad 140 communicating with the first air passage 120 and the second pad 150 communicating with the second air passage 130. That is, in this embodiment, the second pad 150 communicating with the second air passage 130 and the first pad 140 communicating with the first air passage 120 serve as both the pads, and attract and suction the transported object W. As a result, the first pad 140 communicating with the first air passage 120 and the second pad 150 communicating with the second air passage 130 generate suction force to attract and adsorb the transported object W from below the transported object W. As an example, the holding start signal is automatically transmitted after the transport robot 21 reaches the target position to transport the transported object W (after the hand 100 of the transport robot 21 reaches a position below the transported object W).

[0051] Next, in the suction step S12, the transported object W is sucked by the first pad 140 communicating with the first air passage 120 and the second pad 150 communicating with the second air passage 130, and then the process proceeds to the blocking step S13. In this embodiment, the blocking step S13 includes a suction standby step S131 and a second air passage blocking step S132. First, in the suction standby step S131, the transport device 20 continues the suction state of the first air passage 120 and the second air passage 130 in the suction step S12 for a predetermined time. The suction standby step S131 is completed when the predetermined time has elapsed. Note that the completion condition is not limited thereto, and the suction standby step S131 may be completed when at least the first pad 140 has sucked and held the transported object W, without waiting for the predetermined time to elapse. In this case, for example, when the pressure value of the first air passage 120 measured by the pressure measurement unit 215 reaches a predetermined value, it may be determined that the first pad 140 has suction-held the transported object W. Thereafter, in the second air passage blocking step S132, the control unit 26 receives, for example, a second switching unit blocking signal, turns off the second switching unit 251b, and switches the second air passage 130 to a blocked state. That is, the transported object W is suction-held only by the first pad 140, with suction by the second pad 150 communicating with the second air passage 130 stopped. Note that the pressure measurement unit 215 may further measure the suction state of the second air passage 130, and if the pressure values ​​of the first air passage 120 and the second air passage 130 reach a predetermined value, suction by the second pad 150 may be continued. That is, the second air passage blocking step S132 is skipped, and the transported object W is suction-held by the first pad 140 and the second pad 150. In this case, suction by the second pad 150 continues, and the process proceeds to the transporting step S15 after a determination is made in a determination step S14 described below. As one example, the second switching unit blocking signal is automatically sent to the control unit 26 a predetermined time after the transmission of the holding start signal to the control unit 26 (i.e., after the suction standby step S131 is executed). As another example, the second switching unit blocking signal may be sent to the control unit 26 when the pressure value of the first air passage 120 measured by the pressure measurement unit 215 reaches a predetermined value.

[0052] Next, the second air passage 130 is switched to a blocked state in the blocking step S13, and then the process proceeds to the transport step S15. Specifically, this embodiment further includes a determination step S14, which is performed between the blocking step S13 and the transport step S15. If the determination step S14 determines that the pressure value of the first air passage 120 exceeds a predetermined value, the process proceeds to the transport step S15. If the determination step S14 determines that the pressure value of the first air passage 120 is equal to or lower than the predetermined value, the process proceeds to the suction step S12 again. During this process, the transport device 20, for example, receives a pressure value measurement signal, measures the pressure value of the first air passage 120 using the pressure measurement unit 215 provided in the transport robot 21, and performs a determination using the control unit 26 based on the predetermined value. If the determination that the pressure value of the first air passage 120 exceeds the predetermined value, this indicates that the first pad 140 communicating with the first air passage 120 alone is sufficient to suction and hold the transported object W. Since the transported object W can be reliably sucked and held during the transport process, the process proceeds to the transport step S15 (a transport start signal is sent). On the other hand, if it is determined that the pressure value of the first air passage 120 is below the predetermined value, this indicates that the first pad 140, which communicates with the first air passage 120, alone is not sufficient to suck and hold the transported object W. Since there is a risk that the transported object W cannot be reliably sucked and held during the transport process, the process proceeds again to the suction step S12 (a suction start signal is sent). When proceeding to the suction step S12, suction by the first pad 140 and the second pad 150 is stopped. As an example, the pressure value measurement signal is sent automatically a predetermined time after the transmission of the second switching unit shutoff signal, or is sent after the second switching unit shutoff completion signal is received.

[0053] Next, after the second air passage 130 is transitioned to a blocked state in the blocking step S13 and after it is determined in the determination step S14 that the pressure value of the first air passage 120 exceeds a predetermined value, the process proceeds to the transfer step S15. Specifically, in this embodiment, the transfer step S15 includes a transfer robot transfer step S151 and a first air passage blocking step S152. First, in the transfer robot transfer step S151, the control unit 26 receives, for example, a transfer start signal, moves the transfer robot 21, and transfers the transferred object W to a predetermined position (e.g., another slot in the container H or a mounting table of the processing device 60). Subsequently, in the first air passage blocking step S152, after the transferred object W has been transferred to the predetermined position, the control unit 26 receives, for example, a first switching unit blocking signal or a suction and holding completion signal, turns off the first switching unit 251a, and transitions the first air passage 120 to a blocked state. That is, all the air passages and pads are turned off, and suction holding of the transported object W is completed. As an example, the first switching unit shutoff signal or suction holding completion signal is automatically transmitted after the transport robot 21 transports the transported object W to a predetermined position. Note that after the transported object W is transported to the predetermined position in the transport step S15 (for example, after the transported object W is placed in the slot of the container H), a release valve (not shown) may be opened to release the suction holding by the first pad 140 and / or the second pad 150 in order to safely remove the transported object W from the hand 100.

[0054] Finally, in the transport step S15, the transported object W is transported to a predetermined position, and then the process proceeds to the confirmation step S16. Specifically, in this embodiment, the confirmation step S16 includes a remaining number confirmation step S161 and a vacuum source stop step S162. First, in the remaining number confirmation step S161, after the transported object W is transported to the predetermined position, the control unit 26 receives, for example, a remaining number confirmation signal and confirms whether there are any more transported objects W to be transported by the transport device 20, or the number of such objects. That is, the control unit 26 confirms whether to continue transporting the next transported object W using the transport robot 21 provided in the transport device 20. If the control unit 26 confirms that there is a next transported object W, the process proceeds again to the transport robot movement step S112 of the start step S11 (sends a movement start signal), and executes the suction step S12, the shut-off step S13, the determination step S14, and the transport step S15 described above. If the control unit 26 confirms that there are no more transported objects W, the process proceeds to the vacuum source stop step S162. In the vacuum source stopping step S162, the transfer device 20 receives, for example, a transfer completion signal, turns off the vacuum source V, and ends the transfer of the transferred objects W. As an example, the transfer completion signal is automatically transmitted when it is confirmed that the transfer of all the transferred objects W is completed.

[0055] As can be seen from this, the hand 100 attached to the transport device 20 used in the method for transporting the transported object W of this embodiment includes a first pad 140 communicating with the first air passage 120 and a second pad 150 communicating with the second air passage 130. As described above, the second pad 150 has a larger air suction volume per unit time than the first pad 140, and therefore the second pad 150 is advantageous for attracting the transported object W and bringing the transported object W into close contact with the first pad 140 and the second pad 150, and the first pad 140 is advantageous for stably suctioning and holding the transported object W. In this embodiment, in the suction step S12, in order to promote suction of the transported object W by the first pad 140, the first air passage 120 and the second air passage 130 are switched to a suction state, and the transported object W is drawn to the first pad 140 by the suction forces from the first pad 140 and the second pad 150 (mainly the suction force from the second pad 150, which has a larger suction amount). After the transported object W is suction-held by the first pad 140, the second air passage 130 is switched to a blocked state so that the inflow of air from the second pad 150 does not affect the suction-holding of the transported object W by the first pad 140. Since no air flows in from the second pad 150, whose suction amount (suction force) has become zero, the first pad 140 can stably suction-hold the transported object W. In this way, even if one of the multiple first pads 140 becomes out of contact with the transported object W due to warping of the transported object W, the amount of air flowing in through the gap between the transported object W and the out-of-contact first pad 140 is small, thereby preventing a decrease in the holding force for suction-holding the transported object W. Furthermore, since the second air passage 130 is switched to a blocked state during transport of the transported object W, even if a gap occurs between the transported object W and the second pad 150, air does not flow in through the gap, and the holding force of the first pad 140 for suction-holding the transported object W does not decrease. As a result, the method for transporting the transported object W of this embodiment can reliably suction-hold the transported object W by ensuring sufficient suction force of the pad while preventing air from flowing in through the gap between the out-of-contact pad and the transported object W, even if the transported object W warps.

[0056] Next, with reference to FIGS. 1 to 6 and 12 , a method for transporting a transported object W using a transport device 20 equipped with the hand 100 according to the second embodiment will be described step by step. The method for transporting a transported object W is a method for transporting a transported object W using a transport device 20 equipped with a hand 100 that holds the transported object W, and mainly includes a start step S21 (including a vacuum source drive step S211 and a transport robot movement step S212), a suction step S22, a cutoff step S23 (including a suction standby step S231 and a second air passage cutoff step S232), a determination step S24, a transport step S25 (including a transport robot transport step S251 and a first air passage cutoff step S252), and a confirmation step S26 (including a remaining number confirmation step S261 and a vacuum source stop step S262). Note that the steps other than the suction step S22 are similar to those in the first embodiment, and therefore description thereof will be omitted. Note that the determination step S24 and the confirmation step S26 may be omitted.

[0057] In the suction step S22, the control unit 26 receives, for example, a holding start signal and drives the switching unit 25 to change the communication state of the first air passage 120 and the second air passage 130. Specifically, the suction step S22 of the second embodiment differs from the suction step S12 of the first embodiment in that it includes a first suction step S221 and a second suction step S222. In the first suction step S221, the control unit 26 receives, for example, a holding start signal and turns off the first switching unit 251a to switch the first air passage 120 to a blocked state, and when the first air passage 120 is in the blocked state, turns on the second switching unit 251b to switch the second air passage 130 to a suction state, thereby sucking the transported object W by the second pad 150 connected to the second air passage 130. Furthermore, in the second suction step S222, the control unit 26 waits for a predetermined time, for example, and then turns on the first switching unit 251a while the second air passage 130, which is in the suction state, is sucking or adsorbing the transported object W, thereby transitioning the first air passage 120 to the suction state and sucking the transported object W with the first pad 140 communicating with the first air passage 120. That is, in this embodiment, the second pad 150 communicating with the second air passage 130 and the first pad 140 communicating with the first air passage 120 are used in turn to attract and then adsorb the transported object W. As a result, the first pad 140 communicating with the first air passage 120 and the second pad 150 communicating with the second air passage 130 can generate suction forces to attract and then adsorb the transported object W from below the transported object W.

[0058] In this embodiment, in the suction step S12, the second pad 150 draws the transported object W (first suction step S221) and the first pad 140 suction-holds the transported object W (second suction step S222) in sequence. In the first suction step S221, of the first air passage 120 and the second air passage 130 that communicate with the same vacuum source V, only the second air passage 130 is placed in a suction state, causing suction force to be generated only from the second pad 150. Compared to when both the first air passage 120 and the second air passage 130 are in a suction state, the suction force of the vacuum source V is not dispersed, and sufficient suction force is generated in the second pad 150. Therefore, the transported object W can be reliably drawn toward the second pad 150. Furthermore, in the second suction step S222, while the transported object W is being pulled toward the second pad 150 in the first suction step S221, the first air passage 120 is transitioned to a suction state. When the transported object W is being pulled toward the second pad 150, the transported object W is also close to the first pad 140, so the transported object W can be reliably sucked and held by the suction force from the first pad 140. As a result, the transport method for the transported object W of this embodiment can sufficiently attract the transported object W with the second pad 150, which has a strong suction force, so that the transported object W can be sucked and held even with the first pad 140, which has a weak suction force. Furthermore, even if the transported object W is warped, the suction force of the pad can be sufficiently secured to reliably suck and hold the transported object W while preventing air from entering through the gap between the non-contact pad and the transported object W.

[0059] In summary, the hand of the present invention includes a first suction system formed by a first air passage and a first pad communicating therewith, and a second suction system formed by a second air passage and a second pad communicating therewith, and sucks the transported object with different suction levels. When transporting an object using a hand provided with first and second pads with different suction levels, the object is reliably drawn to the upper surface of the hand by the pad with the greater suction level (i.e., the second pad), and the object is reliably held by suction only by the pad with the smaller suction level (i.e., the first pad). For example, the object is drawn by at least the second pad with the greater suction level, and the object is held by suction only by the first pad with the smaller suction level (transitioning the second air passage to a closed state), and transported. This ensures sufficient suction force of the first pad to reliably hold the transported object, even if the transported object warps, while preventing air from entering through the gap between the non-contacting first or second pad and the transported object.

[0060] Finally, it should be noted that the above embodiments are only used to explain the technical solutions of the present invention, and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will understand that the technical solutions described in the above embodiments can still be modified or some or all of the technical features can be replaced with equivalents, provided that such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0061] The hand of the present invention, the transport device to which the hand is attached, and the method for transporting a transported object using the transport device can reliably adsorb and hold the transported object even if the transported object warps, while suppressing the inflow of air through the gap between the non-contact pad and the transported object, by ensuring sufficient suction force of the pad.

[0062] 20 Conveying device, 21 Conveying robot, 22 Moving body, 23 Guide structure, 24 Housing, 25 Switching unit, 26 Control unit, 50 Load port, 60 Processing device, 100 Hand, 110 Hand body, 111 Mounting unit, 112 Base unit, 114 Hand unit, 114a; 141a; 142a; 143a; 151a; 152a Upper surface, 114b; 142b; 152b; 160a Lower surface, 114c Base unit, 114d Groove unit, 1141 First finger unit, 1142 Second finger unit, 115 Lid, 116 Installation unit, 1161 First installation unit, 1161a; 1162a Large diameter unit, 1161b; 1162b Small diameter unit, 1161c; 1162c Connection portion, 1162 Second installation portion, 120 First ventilation path, 122 First ventilation portion, 124 First communication portion, 126 First connection hole, 130 Second ventilation path, 132 Second ventilation portion, 134 Second communication portion, 136 Second connection hole, 140; 140A First pad, 141 First extension portion, 142 First engagement portion, 142c; 152c Outer circumferential surface, 142d; 152d Inner circumferential surface, 143 First abutment portion, 144 First extension portion, 144a First base end portion, 144b First tip portion, 144c First jaw portion, 146 First suction surface, 148 First suction space, 149 First inlet portion, 150 Second pad, 151 Second extension portion, 152 Second engagement portion, 154 Second extension portion, 154a Second base end portion, 154b Second tip portion, 154c Second jaw portion, 156 Second suction surface, 158 Second suction space, 159 Second inlet portion, 160 Throttle member, 162 Through hole, 211 Robot arm, 212a Main body portion, 212b Drive portion, 212c Main body wall portion, 213 Connection portion, 213a First connection path, 213b Second connection path, 214 Suction path, 215 Pressure measurement portion, 251a First switching portion, 251b Second switching portion, 252a First connection terminal, 252b Second connection terminal, 253a First control connector, 253b Second control connector, 254a First power connector, 254b Second power connector, C1; C2 Virtual circle, CL1; CL2; L Center line, H Container, H1; H2 Height, P Reference point, P1 First position, P2 Second position, S1; S2; S3; S4 Area, S11; S21 Starting process, S111; S211 Vacuum source driving process, S112; S212 Transfer robot movement process, S12;S231: Suction standby step, S132; S232: Second air passage blocking step, S14; S24: Determination step, S15; S25: Transport step, S151; S251: Transport robot transport step, S152; S252: First air passage blocking step, S16; S26: Confirmation step, S161; S261: Remaining number confirmation step, S162; S262: Vacuum source stopping step, S221: First suction step, S222: Second suction step, V: Vacuum source, W: Transported object;

Claims

1. A hand that is attached to a transport device and holds a transported object, comprising: a hand body; a first air passage connected to a vacuum source; a second air passage connected to the vacuum source; a first pad that communicates with the first air passage and adsorbs the transported object; and a second pad that communicates with the second air passage and sucks the transported object, wherein a plurality of the first pads and the second pads are provided on the hand body, and the first pad has a smaller suction amount than the second pad.

2. The hand described in claim 1, further comprising: a plurality of first mounting portions on which the first pad is mounted; and a plurality of second mounting portions on which the second pad is mounted; the first pad is hollow and has a first engagement portion that engages with the first mounting portion, a first extension portion that extends from the first engagement portion, and a first through hole that communicates with the first air passage; and the second pad is hollow and has a second engagement portion that engages with the second mounting portion, a second extension portion that extends from the second engagement portion, and a second through hole that communicates with the second air passage.

3. The hand described in claim 2, characterized in that the second extension portion is configured so that its end is displaceable between a first position in which it is farther away from the top surface of the hand body than the end of the first extension portion, and a second position in which it is closer to the top surface of the hand body than the end of the first extension portion.

4. The hand described in claim 2, characterized in that the area of ​​the first through hole is smaller than the area of ​​the second through hole.

5. The hand described in claim 1, characterized in that the hand body has a base provided with a first connection hole connecting the first air passage and the vacuum source and a second connection hole connecting the second air passage and the vacuum source, and a hand portion including a first finger portion and a second finger portion extending from the base in two branches, the first pad and the second pad being provided on the first finger portion and the second finger portion, respectively.

6. The hand according to claim 1, characterized in that three of the second pads are arranged on the same circumference on the hand body.

7. The hand according to claim 1, characterized in that the second pads are arranged on the same circumference with a reference point located on a center line extending along the extension direction of the hand body as its center.

8. The hand described in claim 1, characterized in that the hand body has an inner side closer to a reference point located on a center line extending along the extension direction of the hand body, and an outer side away from the reference point, and the second pad is provided on the hand body further inward than the first pad.

9. The hand described in claim 8, characterized in that the first air passage and the second air passage are formed at different positions on the hand body so as not to communicate with each other, and the first air passage is formed further outboard than the second air passage.

10. The hand according to claim 1, characterized in that the first air passage and the second air passage are formed at different positions on the hand body so as not to communicate with each other.

11. The hand according to claim 10, characterized in that the first air passage and the second air passage are formed at different positions on the hand body so as not to overlap each other in a plan view.

12. A transport device comprising: a hand as defined in any one of claims 1 to 11; a transport robot which freely moves the hand; a switching unit which switches the communication state of each of the first air passage and the second air passage; and a control unit which controls the switching unit, wherein the switching unit switches the communication state between a suction state in which the air suction force of the vacuum source is applied and a cut-off state in which the air suction force of the vacuum source is not applied.

13. The conveying device described in claim 12, characterized in that the switching unit comprises a first switching unit that switches the communication state of the first air passage and a second switching unit that switches the communication state of the second air passage, and the control unit controls the second switching unit to transition the second air passage to a blocked state before starting conveying of the conveyed object.

14. A conveying device as described in claim 13, further comprising a pressure measuring unit that measures a pressure value of the first air passage, and wherein the control unit controls the second switching unit to transition the second air passage to a suction state when the pressure value of the first air passage measured by the pressure measuring unit is equal to or lower than a predetermined value.

15. A method for transporting an object by a transport device having a hand for holding the object, wherein the hand comprises a hand body, a first air passage connected to a vacuum source, a second air passage connected to the vacuum source, a first pad communicating with the first air passage and suctioning the object, and a second pad communicating with the second air passage and sucking the object, wherein a plurality of the first pad and the second pad are provided on the hand body, and the first pad has a smaller suction amount than the second pad, the method for transporting the object comprising the steps of: a suction step of sucking the object by the first pad communicating with the first air passage and the second pad communicating with the second air passage; a blocking step of switching the second air passage to a blocked state after the object has been suctioned and held; and a transport step of transporting the object to a predetermined position.

16. The method for transporting a transported object as described in claim 15, characterized in that the suction step includes a first suction step and a second suction step, the first suction step transitions the second air passage to a suction state when the first air passage is in a blocked state, and sucks the transported object with the second pad so as to draw it in, and the second suction step transitions the first air passage to a suction state while the transported object is being adsorbed by the second air passage in the suction state, and sucks the transported object with the first pad so as to hold it.

17. A method for transporting an object as described in claim 16, further comprising a determination step performed between the blocking step and the transporting step, wherein if it is determined in the determination step that the pressure value of the first air passage exceeds a predetermined value, the method transitions to the transporting step, and if it is determined that the pressure value of the first air passage is equal to or lower than the predetermined value, the method transitions again to the suction step.

Images