Hand, conveying device, and method for conveying an object to be conveyed

Abstract

To provide a hand using a pad capable of adsorbing and holding even a warped transported object, a transport device to which the hand is attached, and a transport method for the transported object using the transport device.SOLUTION: A hand according to the present invention includes a hand body, a first air passage, a second air passage, a first pad communicating with the first air passage and suctioning a transported object, and a second pad communicating with the second air passage and suctioning the transported object, the plurality of first pad and the plurality of second pad are provided in plurality on the hand body, and the first pad has a smaller suction amount than the second pad. A transport device includes the hand, a transport robot, a switching unit that switches the communication states of the first air passage and the second air passage, and a control unit. A transport method for a transported object is executed by the transport device, and includes a suction step of sucking the transported object, a blocking step of switching the second air passage to a blocked state after the transported object is sucked and held, and a transport step of transporting the transported object.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hand, a conveying device, and a method for conveying an object to be conveyed.

Background Art

[0002] Conventionally, in the field of manufacturing such as semiconductors, an object to be conveyed (for example, a wafer, a glass substrate, etc.) accommodated in a storage container called a FOUP (Front Opening Unified Pod) is conveyed from the FOUP to various processing devices by a conveying device, and processing is performed on the conveyed object to be conveyed. Among them, as a conveying mechanism, the conveying device includes a conveying robot including a robot arm that can move vertically and horizontally, and a hand having an adsorbing member such as a pad that is attached to the robot arm and adsorbs and holds the object to be conveyed. For example, as a method of conveying an object to be conveyed by a conveying robot, a method of taking out the object to be conveyed from a storage container by moving the robot arm while adsorbing and holding the object to be conveyed by a hand is known.

[0003] If the object to be conveyed is warped or distorted, when conveying in an adsorbed and held state, there is a possibility that some pads and the object to be conveyed may become non-contact. In this case, air flows in from the gap between the pad and the object to be conveyed, and the intake pressure decreases, so the force for adsorbing and holding the object to be conveyed by the pad (hereinafter, holding force) may decrease. Therefore, in Patent Document 1, a hand is proposed in which the air flow path of the pad is set to a fine diameter, and the amount of air sucked by the pad per unit time (sucking amount) is intentionally suppressed, thereby suppressing the amount of air flowing in per unit time from the gap between the pad and the object to be conveyed and suppressing the decrease in the intake pressure.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the hand of Patent Document 1, since the amount of air sucked by the pad is small, the force for attracting the object to be conveyed to the pad (hereinafter referred to as the suction force) decreases. In this case, the pad cannot draw the object to be conveyed to the adsorption surface of the pad, the total number of pads for adsorbing and holding the object to be conveyed decreases, and there is a risk that sufficient holding force cannot be obtained.

[0006] From the above, there is a need for a hand that can adsorb and hold an object to be conveyed while suppressing the inflow of air from the gap between the object to be conveyed and the pad, a conveying device equipped with the hand, and a method for conveying an object to be conveyed using the conveying device.

[0007] Therefore, the present invention provides a hand using a pad that can adsorb and hold even a warped object to be conveyed, a conveying device equipped with the hand, and a method for conveying an object to be conveyed using the conveying device.

Means for Solving the Problems

[0008] In order to achieve the above object, according to the present invention, there is provided a hand attached to a conveying device for holding an object to be conveyed, the hand including a hand body, a first ventilation path connected to a vacuum source, a second ventilation path connected to the vacuum source, a first pad communicating with the first ventilation path and adsorbing the object to be conveyed, and a second pad communicating with the second ventilation path and sucking the object to be conveyed, 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.

[0009] In order to achieve the above object, according to the present invention, there is provided a conveying device including the hand, a conveying 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. The switching unit switches the communication state between a suction state in which the suction force of air by the vacuum source is exerted and a shut-off state in which the suction force of air by the vacuum source is not exerted.

[0010] In order to achieve the above object, according to the present invention, there is provided a method for conveying an object to be conveyed by a conveying device including a hand that holds the object to be conveyed. The hand includes 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 to be conveyed, and a second pad that communicates with the second air passage and sucks the object to be conveyed. A plurality of the first pads and the second pads are provided on the hand body. The first pad has a smaller suction amount than the second pad. The method for conveying the object to be conveyed includes a suction step of sucking the object to be conveyed by the first pad communicating with the first air passage and the second pad communicating with the second air passage, a shut-off step of shifting the second air passage to a shut-off state after adsorbing and holding the object to be conveyed, and a conveying step of conveying the object to be conveyed to a predetermined position.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a hand using a pad that can adsorb and hold even a warped object to be conveyed, a conveying device equipped with the hand, and a method for conveying an object to be conveyed using the conveying device.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0013] Here, exemplary embodiments of the present invention will be referred to in detail, and examples of the exemplary embodiments are shown in the accompanying drawings. Hereinafter, in combination with FIGS. 1 to 13, the hand 100 of the present embodiment, the conveying device 20 having the hand 100, and the flow of a method for conveying an object W to be conveyed using the conveying device 20 having the hand 100 will be described. However, this is only an example of the present invention, and the present invention is not limited thereto.

[0014] First, referring to FIGS. 1 to 5, the hand 100 of the present embodiment will be described. In the present embodiment, the hand 100 is attached to the robot arm 211 of the transfer robot 21 of the transfer device 20 and holds the object to be transferred W (for example, a wafer). The hand 100 includes a hand body 110, a first ventilation path 120, a second ventilation path 130, a first pad 140, and a second pad 150. The first ventilation path 120 is connected to a vacuum source V (for example, a vacuum pump). The first pad 140 communicates with the first ventilation path 120 and sucks and adsorbs the object to be transferred W. The second ventilation path 130 is connected to the vacuum source V. The second pad 150 communicates with the second ventilation path 130 and sucks and adsorbs the object to be transferred W. A plurality of the first pads 140 and the second pads 150 (for example, four first pads 140 and three second pads 150) are provided on the hand body 110. The first ventilation path 120 and the first pad 140 form a first suction system, and the second ventilation path 130 and the second pad 150 form a second suction system. Also, the amount of air sucked per unit time (suction amount) of the first pad 140 is smaller than that of the second pad 150. Here, suction means attracting the object to be transferred 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 attracted object to be transferred W into close contact with the first pad 140 and / or the second pad 150. Also, adsorption means that the first pad 140 and / or the second pad 150 in close contact with the object to be transferred W holds the object to be transferred W by negative pressure. Therefore, both the first pad 140 and the second pad 150 can suck and adsorb the object to be transferred W, but the first pad 140 with a small suction amount mainly functions to adsorb the object to be transferred W, and the second pad 150 with a large suction amount mainly functions to suck the object to be transferred W. However, the present invention is not limited to this.

[0015] Specifically, the hand body 110 of the hand 100 includes a base portion 112 provided with a first connection hole 126 connecting the first ventilation path 120 and the vacuum source V, and a second connection hole 136 connecting the second ventilation path 130 and the vacuum source V, and a hand portion 114 extending from the base portion 112. The base portion 112 includes a mounting portion 111 (for example, the holes shown in FIGS. 1 and 2) to be mounted on the robot arm 211 of the transfer robot 21. The hand portion 114 is provided with a first pad 140 and a second pad 150. The hand portion 114 holds the object to be transferred W by the first pad 140 adsorbing the object to be transferred W. As an example, the hand body 110 is a substantially Y-shaped base (for example, a plate), and the portion bifurcated and extending from the base portion 112 corresponds to the hand portion 114. The hand portion 114 has a first finger portion 1141 corresponding to one side of the portion bifurcated and extending from the base portion 112, and a second finger portion 1142 corresponding to the other side of the portion bifurcated and extending. The first pad 140 and the second pad 150 are provided on the first finger portion 1141 and the second finger portion 1142, respectively. That is, the first finger portion 1141 is provided with the first pad 140 and the second pad 150. Similarly, the second finger portion 1142 is provided with the first pad 140 and the second pad 150. The first ventilation path 120 and the second ventilation path 130 are paths through which air can flow, and are respectively provided in the hand body 110. As an example, the first ventilation path 120 and the second ventilation path 130 are formed by opening grooves or holes inside the hand body 110 (for example, the portions indicated by broken lines in FIGS. 1 and 4). Note that the hand body 110 may be configured by laminating two plate materials vertically. That is, grooves or holes are dug in the lower surface of the upper plate of the hand body 110, and the lower plate as a lid is attached to the upper plate to cover the grooves or holes (as described in the following explanation), and the first ventilation path 120 and the second ventilation path 130 may be respectively formed inside the hand body 110 composed of the upper plate and the lower plate by the above-described grooves or holes.

[0016] Furthermore, the first ventilation passage 120 includes a first ventilation portion 122 provided at the base portion 112 along the extending direction of the hand body 110 (i.e., the left-right direction in the drawing) and communicating with the vacuum source V, a first communication portion 124 provided at the hand portion 114 and communicating with each of the plurality of first pads 140 provided in the first ventilation portion 122, and a first connection hole 126 connected to the aforementioned vacuum source V. The first ventilation passage 120 extends from the base portion 112 to the hand portion 114, and communicates the vacuum source V provided closer to the conveying device 20 than the base portion 112 with the first pad 140 provided at the hand portion 114. The second ventilation passage 130 includes a second ventilation portion 132 provided at the base portion 112 along the extending direction of the hand body 110 (i.e., the left-right direction in the drawing) and communicating with the vacuum source V, a second communication portion 134 provided at the hand portion 114 and communicating with each of the plurality of second pads 150 provided in the second ventilation portion 132, and a second connection hole 136 connected to the aforementioned vacuum source V. The second ventilation passage 130 extends from the base portion 112 to the hand portion 114, and communicates the vacuum source V provided closer to the conveying device 20 than the base portion 112 with the second pad 150 provided at the hand portion 114. Note that the first ventilation passage 120 and the second ventilation passage 130 may be, for example, metal pipes or plastic tubes attached to the hand body 110 as long as they construct a path through which air can flow.

[0017] Also, in the present embodiment, as shown in FIG. 5, the hand body 110 further includes a plurality of installation portions 116 where the first pads 140 and the second pads 150 are installed. The installation portions 116 are provided at the hand portion 114 corresponding to the positions where the first pads 140 and the second pads 150 are installed. The installation portions 116 communicate the attachment surfaces of the first pads 140 and the second pads 150 (the upper surface 114a of the hand portion 114 in the present embodiment) with the first ventilation passage 120 or the second ventilation passage 130. For example, the installation portion 116 is a through hole penetrating the hand portion 114 from the upper surface 114a to the lower surface 114b of the hand portion 114. The installation portion 116 includes a plurality of first installation portions 1161 where the first pads 140 are installed and a plurality of second installation portions 1162 where the second pads 150 are installed. The structures of the first installation portion 1161 and the second installation portion 1162 will be described below in combination with the structures of the first pads 140 and the second pads 150, respectively.

[0018] Referring to FIGS. 1, 5 to 7, the structure around the first pad 140 of the hand 100 will be described. The hand body 110 has a plurality of first installation portions 1161 where the first pad 140 is installed. The first installation portion 1161 is provided in the hand portion 114 corresponding to the position where the first pad 140 is installed. The first pad 140 is provided on the hand portion 114 of the hand body 110 by the first installation portion 1161. The first installation portion 1161 forms a mounting opening into which the first pad 140 is inserted on the upper surface 114a of the hand portion 114. The first installation portion 1161 communicates the upper surface 114a of the hand portion 114 with the first ventilation passage 120. Specifically described, 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 pedestal for attaching the first pad 140 and fits into an annular recessed structure (described later) formed outside the outer peripheral surface 142c of the first engaging portion 142 of the first pad 140. The large-diameter portion 1161a is provided below the small-diameter portion 1161b, forms a space partitioned on the inner surface of the large-diameter portion 1161a, and communicates with the first ventilation passage 120. It can also be said that the space partitioned on the inner surface of the large-diameter portion 1161a forms a part of the first communication portion 124 of the first ventilation passage 120. As an example, a groove portion 114d provided on the lower surface 114b of the hand portion 114 is formed at the lower part of the large-diameter portion 1161a. The groove portion 114d forms a part of the first communication portion 124 of the first ventilation passage 120 and is covered by the lid 115. That is, at least a part of the first communication portion 124 of the first ventilation passage 120 is formed by the groove portion 114d provided on the lower surface 114b of the hand portion 114 and the lid 115. The connecting 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 portion 114 has a pedestal portion 114c protruding upward from the upper surface 114a. The pedestal portion 114c has a hole forming a mounting opening into which the first pad 140 is inserted and is disposed above the upper part of the small-diameter portion 1161b. The first pad 140 is attached to the first installation portion 1161 so as to be placed on the pedestal portion 114c.Furthermore, since the inner diameter of the hole formed in the pedestal portion 114c is equal to the inner diameter of the small-diameter portion 1161b, the pedestal portion 114c can also be regarded as a part of the small-diameter portion 1161b. The pedestal portion 114c is formed by digging down a portion of the upper surface 114a of the hand portion 114 where the first pad 140 is not disposed by end milling. Also, a plurality of pedestal portions 114c are provided corresponding to the plurality of first installation portions 1161, and the common flatness machining is performed so that the upper surfaces of the plurality of pedestal portions 114c are located on the same plane.

[0019] Correspondingly, the first pad 140 has a hollow shape and includes a first extending portion 141 extending to the large-diameter portion 1161a of the first installation portion 1161, a first engaging portion 142 engaging with the small-diameter portion 1161b of the first installation portion 1161, a first extending portion 144 extending from the first engaging portion 142, and a first through hole (a first inflow portion 149 described later) communicating with the first ventilation passage 120. The first engaging portion 142 has a substantially cylindrical shape extending along the center line CL1 and includes an upper surface 142a, a lower surface 142b, an outer peripheral surface 142c, and an inner peripheral surface 142d. The first extending portion 144 has an annular structure centered on the center line CL1 and includes a first base end portion 144a located radially inward and continuous with the first engaging portion 142, a first tip portion 144b located above and radially outside the first base end portion 144a, and a first jaw portion 144c located between the first base end portion 144a and the first tip portion 144b and radially outside the first engaging portion 142. The first extending portion 141 extends outside the outer peripheral surface 142c of the first engaging portion 142, that is, the radial dimension of the first extending portion 141 is provided to be larger than the radial dimension of the first engaging portion 142. Accordingly, the first extending portion 141 and the first jaw portion 144c of the first extending portion 144 form an annular recessed structure outside the outer peripheral surface 142c of the first engaging portion 142.

[0020] Accordingly, when the first pad 140 is provided on the first installation portion 1161, the first extension portion 141 of the first pad 140 is installed on the large-diameter portion 1161a of the first installation portion 1161, and the upper surface 141a of the first extension portion 141 is installed so as to contact the connection portion 1161c of the first installation portion 1161. Further, the first engaging portion 142 of the first pad 140 is installed on the small-diameter portion 1161b of the first installation portion 1161, and the outer peripheral surface 142c of the first engaging portion 142 is installed so as to contact the inner surface of the small-diameter portion 1161b of the first installation portion 1161. Then, the first extending portion 144 of the first pad 140 is installed on the upper surface of the small-diameter portion 1161b of the first installation portion 1161 (i.e., the upper surface 114a of the handle portion 114 of the handle body 110), and the first jaw portion 144c of the first extending portion 144 is installed so as to contact the upper surface of the small-diameter portion 1161b. Therefore, the first engaging portion 142 of the first pad 140 engages with the small-diameter portion 1161b such that the first jaw portion 144c of the first extending portion 144 and the upper surface 141a of the first extension portion 141 sandwich the small-diameter portion 1161b of the first installation portion 1161, thereby defining the position in the radial direction and the position in the height direction of the first pad 140. That is, the small-diameter portion 1161b of the first installation portion 1161 is inserted into the annular recessed structure formed between the first extension portion 141 and the first jaw portion 144c of the first extending 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 installation portion 1161 in a state of being pressed and deformed, and when it reaches the large-diameter portion 1161a of the first installation portion 1161, the pressing deformation is released. Thereby, the first pad 140 is provided on the first installation portion 1161.

[0021] Also, as shown in FIGS. 5 to 7, the first pad 140 of the present embodiment has a first suction surface 146 formed on a plane defined by the edge at the upper end of the first tip portion 144b. The first pad 140 has a first extension portion 141, a first engagement portion 142, a first extending portion 144, a 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 adsorbs the object W to be conveyed by sucking the air in the first suction space 148. Further, the first pad 140 has a first inflow portion 149 defined by the inner peripheral surface 142d of the first engagement portion 142 at the central portion of the first engagement portion 142. That is, the first engagement portion 142 has a substantially cylindrical shape, and the first inflow portion 149 can also be referred to as a first through hole. The first inflow portion 149 communicates the first suction space 148 and the first ventilation path 120. Therefore, the air in the first suction space 148 flows into the first ventilation path 120 via the first inflow portion 149 and is exhausted from a vacuum source V communicating with the first ventilation path 120. Here, the first extending portion 144 extends in a direction away from the first installation portion 1161 of the hand body 110 with respect to the first engagement portion 142 (a direction away from the upper surface 114a of the hand portion 114 of the hand body 110) and in the radially outward direction. As shown in FIG. 6, the area S1 of the first suction surface 146 is larger than the area S2 of the first inflow portion 149. Note that the area S2 of the first inflow portion 149 is the cross-sectional area of a plane perpendicular to the extending direction of the first inflow portion 149 and can also be expressed as the cross-sectional area of a plane perpendicular to the direction in which air flows (flow path cross-sectional area).

[0022] Referring to FIGS. 1, 5, 6, and 8, the structure around the second pad 150 of the hand 100 will be described. The hand body 110 has a plurality of second installation portions 1162 where the second pad 150 is installed. The second installation portion 1162 is provided in the hand portion 114 corresponding to the position where the second pad 150 is installed. The second pad 150 is provided in the hand portion 114 of the hand body 110 by the second installation portion 1162. The second installation portion 1162 forms a mounting opening into which the second pad 150 is inserted on the upper surface 114a of the hand portion 114. The second installation portion 1162 communicates the upper surface 114a of the hand portion 114 with the second ventilation passage 130. The second installation portion 1162 for installing the second pad 150 has a large-diameter portion 1162a, a small-diameter portion 1162b, and a connecting portion 1162c, similar to the first installation portion 1161 for installing the first pad 140 described above. The small-diameter portion 1162b is a pedestal for attaching the second pad 150, and fits into an annular recessed structure (described later) formed outside the outer peripheral 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, forms a space partitioned on the inner surface of the large-diameter portion 1162a, and communicates with the second ventilation passage 130. It can also be said that the space partitioned on the inner surface of the large-diameter portion 1162a forms a part of the second communication portion 134 of the second ventilation passage 130. As an example, a groove portion 114d provided on the lower surface 114b of the hand portion 114 is formed at the lower part of the large-diameter portion 1162a. The groove portion 114d forms a part of the second communication portion 134 of the second ventilation passage 130 and is covered by the lid 115. That is, at least a part of the second communication portion 134 of the second ventilation passage 130 is formed by the groove portion 114d provided on the lower surface 114b of the hand portion 114 and the lid 115. The connecting 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 it is attached to the second installation portion 1162. As an example, a hole for forming a mounting opening into which the second pad 150 is inserted is opened in the pedestal portion 114c of the hand portion 114, and the hole is disposed above the upper portion of the small-diameter portion 1162b. The second pad 150 is attached to the second installation portion 1162 so as to be placed on the pedestal portion 114c.Furthermore, since the inner diameter of the hole formed in the pedestal portion 114c is equal to the inner diameter of the small-diameter portion 1162b, the pedestal portion 114c can also be regarded as a part of the small-diameter portion 1162b. The pedestal portion 114c is formed by digging down a portion of the upper surface 114a of the handle portion 114 where the second pad 150 is not disposed by end milling. Also, a plurality of pedestal portions 114c are provided corresponding to the plurality of second installation portions 1162, and the upper surfaces of the plurality of pedestal portions 114c are subjected to coplanar machining so that they are located on the same plane. Furthermore, the upper surface of the pedestal portion 114c provided corresponding to the second installation portion 1162 and the upper surface of the pedestal portion 114c provided corresponding to the first installation portion 1161 are located on the same plane.

[0023] Correspondingly, the second pad 150 has a hollow shape and includes a second extending portion 151 that extends to the large-diameter portion 1162a of the second installation portion 1162, a second engaging portion 152 that engages with the small-diameter portion 1162b of the second installation portion 1162, a second extending portion 154 that extends from the second engaging portion 152, and a second through hole (a second inflow portion 159 described later) that communicates with the second air passage 130. The second engaging portion 152 has a substantially cylindrical shape that extends along the center line CL2 and includes an upper surface 152a, a lower surface 152b, an outer peripheral surface 152c, and an inner peripheral surface 152d. The second extending portion 154 has an annular structure centered on the center line CL2 and includes a second base end portion 154a that is located radially inward and continuous with the second engaging portion 152, a second tip portion 154b that is located above and radially outward of the second base end portion 154a, and a second jaw portion 154c that is located between the second base end portion 154a and the second tip portion 154b and radially outward of the second engaging portion 152. The second extending portion 151 extends outside the outer peripheral surface 152c of the second engaging portion 152, that is, the radial dimension of the second extending portion 151 is provided to be larger than the radial dimension of the second engaging portion 152. Therefore, the second extending portion 151 and the second jaw portion 154c of the second extending portion 154 form an annular concave structure outside the outer peripheral surface 152c of the second engaging portion 152.

[0024] Accordingly, when the second pad 150 is provided on the second installation portion 1162, the second extension portion 151 of the second pad 150 is installed on the large-diameter portion 1162a of the second installation portion 1162, and the upper surface 151a of the second extension portion 151 is installed so as to abut against the connection portion 1162c of the second installation portion 1162. Further, the second engaging portion 152 of the second pad 150 is installed on the small-diameter portion 1162b of the second installation portion 1162, and the outer peripheral surface 152c of the second engaging portion 152 is installed so as to abut against the inner surface of the small-diameter portion 1162b of the second installation portion 1162. And the second extending portion 154 of the second pad 150 is installed on the upper surface of the small-diameter portion 1162b of the second installation portion 1162 (that is, 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 installed so as to abut against the upper surface of the small-diameter portion 1162b. Therefore, the second engaging portion 152 of the second pad 150 engages with the small-diameter portion 1162b such that the second jaw portion 154c of the second extending portion 154 and the upper surface 151a of the second extension portion 151 sandwich the small-diameter portion 1162b of the second installation portion 1162, thereby defining the position in the radial direction and the position in the height direction of the second pad 150. That is, the small-diameter portion 1162b of the second installation portion 1162 is inserted into the annular recessed structure formed between the second extension portion 151 and the second jaw portion 154c of the second extending 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 installation portion 1162 in a state of being press-deformed, and when it reaches the large-diameter portion 1162a of the second installation portion 1162, the press-deformation is released. Thereby, the second pad 150 is provided on the second installation portion 1162.

[0025] Also, as shown in FIGS. 5, 6, and 8, the second pad 150 of the present embodiment has a second adsorption surface 156 formed on a plane defined by the edge of the upper end of the second tip portion 154b. The second pad 150 has a second extending portion 151, a second engaging portion 152, a second extending portion 154, a second adsorption surface 156, and a second suction space 158 defined by the upper surface 152a of the second engaging portion 152. The second pad 150 sucks the object to be conveyed W by sucking the air in the second suction space 158. Further, the second pad 150 has a second inflow portion 159 defined by the inner peripheral surface 152d of the second engaging portion 152 at the central portion of the second engaging portion 152. That is, the second engaging portion 152 has a substantially cylindrical shape, and the second inflow portion 159 can also be referred to as a second through hole. The second inflow portion 159 communicates the second suction space 158 with the second ventilation path 130. Therefore, the air in the second suction space 158 flows into the second ventilation path 130 via the second inflow portion 159 and is exhausted from a vacuum source V communicating with the second ventilation path 130. Here, the second extending portion 154 extends in a direction away from the second engaging portion 152 with respect to the second installation portion 1162 of the hand body 110 (a direction away from the upper surface 114a of the hand portion 114 of the hand body 110) and in the radially outer direction. As shown in FIG. 6, the area S3 of the second adsorption surface 156 is larger than the area S4 of the second inflow portion 159. Note that the area S4 of the second inflow portion 159 is the cross-sectional area of a plane perpendicular to the extending direction of the second inflow portion 159 and can also be expressed as the cross-sectional area of a plane perpendicular to the direction in which air flows (flow path cross-sectional area).

[0026] More specifically, in the present embodiment, two types of pads with different suction amounts are used to suck and adsorb and hold the object W to be conveyed. Among them, the first pad 140 has a smaller suction amount than the second pad 150. As an example, as shown in FIGS. 5 and 6, the first pad 140 has a first inflow portion 149 (first through hole) at the center of the first engaging portion 142, and the second pad 150 has a second inflow portion 159 (second through hole) at the center of the second engaging portion 152. Further, the area S2 of the first inflow portion 149 (first through hole) is smaller than the area S4 of the second inflow portion 159 (second through hole). Therefore, the amount of air flowing in per unit time through the first inflow portion 149 is smaller than that through the second inflow portion 159. Accordingly, the suction amount of the first pad 140 can be limited to be smaller than the suction amount of the second pad 150. As an example, the thickness (radial width) of the first engaging portion 142 of the first pad 140 may be made larger than the thickness (radial width) of the second engaging portion 152 of the second pad 150 so that the area S2 of the first inflow portion 149 is smaller than the area S4 of the second inflow portion 159.

[0027] As an example, in another embodiment shown in FIG. 9, the suction amount of the first pad 140A is restricted to be smaller than the suction amount of the second pad 150 by means different from those in the embodiments shown in FIGS. 5 to 7. As shown in FIG. 9, the hand 100 further has a throttle member 160 that is inserted into a first inflow portion 149 (first through hole) formed in the central portion of the first engaging portion 142 of the first pad 140A. The throttle member 160 has a hollow shape with a through hole 162 and restricts the suction amount of the first pad 140A to be smaller than the suction amount of the second pad 150. The throttle member 160 is inserted into the first inflow portion 149 and its radial position is defined by engaging with the inner peripheral surface 142d of the first engaging portion 142. Further, the first pad 140A has a first abutting portion 143 that extends inward from the inner peripheral surface 142d of the first engaging portion 142, and the throttle member 160 has its lower surface 160a engage with the upper surface 143a of the first abutting portion 143 of the first pad 140A, thereby defining its height position. Therefore, the area of the first inflow portion 149 in the first pad 140A becomes as small as the area of the through hole 162 of the throttle member 160. Therefore, the suction amount of the first pad 140A can be restricted to be smaller than the suction amount of the second pad 150. Thereby, the first pad 140A adsorbs and holds the object to be conveyed W with a small suction amount, and the second pad 150 attracts the object to be conveyed W with a large suction amount.

[0028] Also, as shown in FIG. 5, in the present 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 higher 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 (the upper surface of the pedestal portion 114c if the pedestal portion 114c is provided) to the upper end of the first tip portion 144b. Also, the height H1 of the first pad 140 can also be said to indicate a position (separated position) where the first tip portion 144b is separated 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 (the upper surface of the pedestal portion 114c if the pedestal portion 114c is provided) to the upper end of the second tip portion 154b. Also, the height H2 of the second pad 150 can also be said to indicate a position (separated position) where the second tip portion 154b is separated from the upper surface 114a of the hand portion 114 of the hand body 110. That is, the upper end of the second tip portion 154b of the second pad 150 is located at a position separated from the upper surface 114a of the hand portion 114 of the hand body 110 more than the upper end of the first tip portion 144b of the first pad 140. In other words, the second adsorption surface 156 of the second pad 150 is located at a position separated from the upper surface 114a of the hand portion 114 of the hand body 110 more than the first adsorption surface 146 of the first pad 140.

[0029] Further, the second extending portion 154 of the second pad 150 is configured to be displaceable between a first position P1 where the end of the second extending portion 154 (i.e., the upper end of the second tip portion 154b) is spaced apart from the upper surface 114a of the hand portion 114 of the hand body 110 more than the end of the first extending portion 144 (i.e., the upper end of the first tip portion 144b), and a second position P2 (shown by the dashed line in FIG. 5) where it approaches the upper surface 114a of the hand portion 114 of the hand body 110 more than the end of the first extending portion 144. Thereby, the second pad 150 is in a first position P1 spaced apart from the upper surface 114a of the hand portion 114 of the hand body 110 more than the height H1 of the first pad 140 in the normal state, and in a state of transporting the object to be transported W, it is below the height H1 of the first pad 140 and can be displaced between the first position P1 and the second position P2 that approaches the upper surface 114a of the hand portion 114 of the hand body 110 more than the first position P1. Note that the normal state of the second pad 150 is a state where the second pad 150 is not affected by the object to be transported W. In other words, the normal state of the second pad 150 is a state where the second pad 150 is not deformed or displaced by the suction and / or adsorption of the object to be transported W, or the weight of the object to be transported W supported and / or adsorbed on the second pad 150.

[0030] Specifically, referring to FIGS. 1 to 5, when the conveyed object W is conveyed by the hand 100, the hand body 110 of the hand 100 is moved by the conveying robot 21 of the conveying device 20 shown in FIG. 3 to below the conveyed object W, and the vacuum source V is driven. When the vacuum source V is driven, the air in the first suction space 148 of the first pad 140 flows into the first ventilation path 120 through the first inflow portion 149. At this time, a suction force is generated on the first pad 140. Similarly, when the vacuum source V is driven, the air in the second suction space 158 of the second pad 150 flows into the second ventilation path 130 through the second inflow portion 159. At this time, a suction force is generated on the second pad 150 (the suction timing of the first pad 140 and the second pad 150 will be described in the following explanation). Therefore, the second pad 150 sucks the conveyed object W with a larger suction amount than the first pad 140 at a position higher than the first pad 140 (for example, the first position P1) below the conveyed object W. When the second adsorption surface 156 of the second pad 150 is in contact with the conveyed object W, the air in the second suction space 158 of the second pad 150 is sucked by the vacuum source V and / or due to the weight of the conveyed object W supported by the second pad 150, the height of the second pad 150 is displaced to a position close to the first pad 140 (for example, the height H1 of the first adsorption surface 146 of the first pad 140). Further, when the second pad 150 pulls the conveyed object W to a position close to the first pad 140, the first adsorption surface 146 of the first pad 140 comes into contact with the conveyed object W, and the first pad 140 adsorbs and holds the conveyed object W. The second pad 150 is displaced to the same position as the height of the first pad 140 (no warping amount) or a position lower than the first pad 140 (downward warping) according to the warping of the conveyed object W. Of course, the second pad 150 may be located at a position higher than the first pad 140 with respect to the warping of the conveyed object W (for example, between the first position P1 and the height position of the first pad 140), or it is also possible that the second adsorption surface 156 of the second pad 150 is not in contact with the conveyed object W (upward warping) with respect to the warping of the conveyed object W.

[0031] Referring to FIG. 1, in the present embodiment, four first pads 140 are arranged on the same circumference in the hand body 110, and three second pads 150 are arranged on the same circumference in the hand body 110. Specifically, the four first pads 140 are arranged on the circumference of a virtual circle C1 centered on a reference point P. Similarly, the three second pads 150 are arranged on the circumference of a virtual circle C2 centered on the reference point P. The reference point P is a virtual point that can be adjusted according to the structure of the hand body 110. For example, the reference point P is located on a center line L that extends along the extending direction of the hand body 110 (i.e., the left - right direction of 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 of the drawing). The plurality of first pads 140 provided are arranged on the same circumference centered on the reference point P located on the center line L that extends along the extending direction of the hand body 110 (i.e., the left - right direction of the drawing), and adsorb the conveyed object W such that the center of the circular conveyed object W corresponds to the reference point P. Similarly, the plurality of second pads 150 provided are arranged on the same circumference centered on the reference point P located on the center line L that extends along the extending direction of the hand body 110 (i.e., the left - right direction of the drawing), and attract the conveyed object W such that the center of the circular conveyed object W corresponds to the reference point P.

[0032] Also, the virtual circle C1 for installing the first pad 140 and the virtual circle C2 for installing the second pad 150 preferably have the same center (reference point P) as shown in FIG. 1, but the centers of the virtual circle C1 and the virtual circle C2 do not necessarily have to coincide. That is, the virtual circle C1 and the virtual circle C2 may be centered on reference points P set at different positions respectively. Further, the plurality of first pads 140 provided are communicated with each other by the first communication portions 124 of the first air passage 120. As an example, the first communication portion 124 is provided in the handle portion 114 along the installation direction of the circumference of the virtual circle C1, communicates with the plurality of first pads 140 and then communicates with the first air vent portion 122 provided in the base portion 112, but a plurality may be provided and each may communicate the first pad 140 and the first air vent portion 122. Similarly, the plurality of second pads 150 provided are communicated with each other by the second communication portions 134 of the second air passage 130. As an example, the second communication portion 134 is provided in the handle portion 114 along the installation direction of the circumference of the virtual circle C2, communicates with the plurality of second pads 150 and then communicates with the second air vent portion 132 provided in the base portion 112, but a plurality may be provided and each may communicate the second pad 150 and the second air vent portion 132.

[0033] In this embodiment, the reference point P, which is the center of the first pad 140 and the second pad 150, is located on the center line L of the hand body 110, and the object to be conveyed W is adsorbed to the first pad 140 or attracted to the second pad 150 such that the center of the object to be conveyed W corresponds to the centers of the first pad 140 and the second pad 150 (i.e., the reference point P). Therefore, the weight of the object to be conveyed W is distributed between the first pad 140 and the second pad 150 with the reference point P as the center. As shown in FIG. 1, when four first pads 140 are arranged on the circumference of the virtual circle C1, the four first pads 140 are provided on the hand body 110 in two symmetrically left and right pairs with respect to the center line L of the hand body 110, and can apply an equal suction force to the circular object to be conveyed W and stably adsorb the object to be conveyed W. Similarly, as shown in FIG. 1, when three second pads 150 are arranged on the circumference of the virtual circle C2, the three second pads 150 are provided on the hand body 110 in one symmetrically left and right pair with respect to the center line L of the hand body 110 and one is provided on the hand body 110 along the center line L, and can apply an equal suction force to the circular object to be conveyed W and stably attract the object to be conveyed W.

[0034] Further, in this embodiment, as shown in FIG. 1, the diameter of the virtual circle C1 on which the first pad 140 is arranged is different from the diameter of the virtual circle C2 on which the second pad 150 is arranged. As an example, the hand body 110 has an inner side close to the reference point P located on the center line L extending along the extending direction of the hand body 110 (i.e., the left and right direction of the drawing) and an outer side away from the reference point P, and the second pad 150 is provided on the hand body 110 closer to the inner side than the first pad 140. That is, for the virtual circles C1 and C2 centered on the common reference point P, the virtual circle C2 having the circumference on which the second pad 150 is arranged is a circle with a smaller diameter than the virtual circle C1 having the circumference on which the first pad 140 is arranged, and the circumference of the virtual circle C2 is closer to the reference point P than the circumference of the virtual circle C1. By attracting the center side of the object to be conveyed W, which is close to the center of the object to be conveyed W and has a small warpage amount, by the second pad 150, it is possible to avoid the phenomenon that the second suction surface 156 of the second pad 150 and the object to be conveyed W become non-contact.

[0035] In addition, in the present embodiment, the first ventilation passage 120 and the second ventilation passage 130 are formed at different positions of 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 ventilation passage 120 and the second ventilation passage 130 formed in the hand body 110. That is, the first ventilation passage 120 communicating with the first pad 140 and the second ventilation passage 130 communicating with the second pad 150 form independent suction systems. That is, the first ventilation passage 120 and the second ventilation passage 130 are each connected to the vacuum source V, and the air suction of the first pad 140 and the second pad 150 can be respectively operated.

[0036] Also, in the present embodiment, the first ventilation passage 120 and the second ventilation passage 130 are formed at different positions of the hand body 110 so as not to overlap each other in a plan view. Not overlapping each other means that, in a plan view (the thickness direction of the hand body 110), it can also be said that the first ventilation passage 120 and the second ventilation passage 130 do not have an overlapping section. As described above, since the first pad 140 installed along the circumference of the virtual circle C1 is provided outside the hand body 110 compared to the second pad 150 installed along the circumference of the virtual circle C2, the first ventilation passage 120 is formed outside the second ventilation 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. Thus, the entire first ventilation passage 120 is installed outside the entire second ventilation passage 130 in the hand body 110, and the first connection hole 126 connected to the vacuum source V of the first ventilation passage 120 and the second connection hole 136 connected to the vacuum source V of the second ventilation passage 130 are installed at different positions in the hand body 110. In the thickness direction of the hand body 110, although the first ventilation passage 120 and the second ventilation passage 130 overlap each other, it is possible to reduce the thickness of the hand body 110 despite forming two independent suction systems in the hand body 110. In other embodiments not shown, the first ventilation passage 120 and the second ventilation passage 130 may be formed at different positions of the hand body 110 so as not to overlap each other in a side view (for example, the first ventilation passage 120 and the second ventilation passage 130 are formed at different depth positions of the hand body 110), and non-communicating (independent) suction systems may be formed.

[0037] Next, referring to FIGS. 1 to 5 and FIG. 10, the transfer device 20 including the above-described hand 100 will be described. As an example, in the present 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 the door of a container H (for example, FOUP) that houses the object W to be transferred. The transfer device 20 transfers the object W to be transferred between the container H and a processing device 60 for processing the object W to be transferred. 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 guiding 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 guiding structure 23 guides the movement of the moving body 22. The housing 24 houses the transfer robot 21, the moving body 22, and the guiding structure 23. Thereby, the moving body 22 is attached to the guiding structure 23 (for example, a slide rail structure, a conveyor driving device, etc.) and is installed so as to be able to travel freely within the housing 24 by the guiding structure 23. Therefore, the transfer robot 21 provided on the moving body 22 can move freely within the housing 24.

[0038] Also, as shown in FIGS. 1, 3, and 4, the transfer device 20 includes a switching unit 25. The switching unit 25 is provided, for example, on the transfer robot 21 and switches the communication state of each of the first air passage 120 and the second air passage 130. The transfer device 20 includes a control unit 26. The control unit 26 is provided, for example, in the housing 24 and controls the operation of the transfer robot 21, the movement of the moving body 22, and the operation of the switching unit 25. Thereby, the transfer robot 21 to which the hand 100 is attached operates within the housing 24 together with the moving body 22 that moves along the guiding structure 23 within the housing 24 under the control of the control unit 26, and transfers the object W to be transferred to the load port 50 or the processing device 60. Further, the first pad 140 and the second pad can suck and hold the object W to be transferred according to 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 that can be operated under the control of the control unit 26.

[0039] Specifically, referring to FIGS. 3 and 4, in this embodiment, the transfer robot 21 includes a robot arm 211 to which the hand 100 is attached, a main body portion 212a, a drive portion 212b provided inside the main body portion 212a, a connection portion 213, and a suction passage 214. The robot arm 211 is, for example, a horizontally articulated arm in which a plurality of arm members are connected, and is capable of turning movement within a horizontal plane and is configured to be vertically movable by a lifting mechanism (not shown) included in the drive portion 212b. The hand 100 is attached to the tip of the arm member of the robot arm 211 as shown in FIG. 10. Since the transfer robot 21 operates within the housing 24 together with the movement of the moving body 22, it moves via the moving body 22 to the vicinity of the object W to be transferred, and the hand 100 attached to the robot arm 211 can be inserted below the object W by the operation of the robot arm 211 itself (turning or lifting of the arm member). Further, the drive portion 212b is, for example, a motor or a transmission mechanism, and applies a driving force to the robot arm 211.

[0040] As shown in FIG. 4, the connection portion 213 includes a first connection passage 213a communicating with the first ventilation passage 120 and a second connection passage 213b communicating with the second ventilation passage 130. The first connection passage 213a communicates the first ventilation passage 120 with a vacuum source V provided in the transfer device 20. The second connection passage 213b communicates the second ventilation passage 130 with the vacuum source V provided in the transfer device 20. One end side of the suction passage 214 communicates with the first connection passage 213a and the second connection passage 213b, and the other end side is connected to the vacuum source V. That is, the first ventilation passage 120 and the second ventilation passage 130 of the hand 100 communicate with the suction passage 214 via the first connection passage 213a and the second connection passage 213b of the transfer device 20, respectively, and communicate with the vacuum source V via the suction passage 214. Further, 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. In addition, the vacuum source V may constitute a central vacuum system communicating with a plurality of vacuum units. Since the vacuum source V constituting the central vacuum system is always on, the operation of turning on the vacuum source V described later is implemented, for example, by operating a solenoid valve (not shown) provided in the suction passage 214.

[0041] Also, in the present embodiment, the switching unit 25 can switch the communication state between a suction state in which the suction force of air by the vacuum source V acts on each of the first ventilation path 120 and the second ventilation path 130 and a cutoff state in which the suction force of air by the vacuum source V does not act. Among them, as shown in FIG. 4, the switching unit 25 includes a first switching unit 251a that switches the communication state of the first ventilation path 120 and a second switching unit 251b that switches the communication state of the second ventilation path 130. The first switching unit 251a and the second switching unit 251b are, for example, electromagnetic valves and are respectively located at one ends of the first ventilation path 120 and the second ventilation path 130. That is, the first switching unit 251a is installed between the first ventilation path 120 and the suction path 214, and indirectly switches the communication state of the first ventilation path 120 by switching the communication state of the first connection path 213a that communicates with the first ventilation path 120. Similarly, the second switching unit 251b is installed between the second ventilation path 130 and the suction path 214, and indirectly switches the communication state of the second ventilation path 130 by switching the communication state of the second connection path 213b that communicates with the second ventilation path 130. Thereby, the communication state of the first ventilation path 120 can be independently switched by the first switching unit 251a. Also, the communication state of the second ventilation path 130 can be independently switched by the second switching unit 251b. That is, the operation of shifting the communication state of the first ventilation path 120 to the suction state or the cutoff state and the operation of shifting the communication state of the second ventilation path 130 to the suction state or the cutoff state may be performed simultaneously or at different timings as necessary.

[0042] Specifically, when the switching unit 25 receives a signal from the control unit 26, for example, it cuts off the communication state of the first air passage 120 and / or the second air passage 130. 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 the suction state. When the communication state of the first air passage 120 is in the cut-off state, 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 in the cut-off state, the second pad 150 communicating with the second air passage 130 does not suck air. Incidentally, when the switching unit 25 switches the communication state of the first air passage 120 to the cut-off state while the first pad 140 has already adsorbed the object to be conveyed W, the adsorption continues as long as there is no air inflow (that is, the holding pressure (vacuum pressure) does not change). When the communication state of the first air passage 120 is in the suction state, the first pad 140 communicating with the first air passage 120 sucks air. Similarly, when the communication state of the second air passage 130 is in the suction state, the second pad 150 communicating with the second air passage 130 sucks air.

[0043] Also, as shown in FIG. 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 ventilation path 120 of the hand 100 and the first connection path 213a. The electromagnetic valve as the first switching unit 251a can switch the communication state of the first connection path 213a connected to the first connection terminal 252a. The second connection terminal 252b connects the second ventilation path 130 of the hand 100 and the second connection path 213b. The electromagnetic valve as the second switching unit 251b can switch the communication state of the second connection path 213b connected to the second connection terminal 252b. Also, a harness or the like that enables communication with the control unit 26 provided in the transfer device 20 is connected to the first control connector 253a and the second control connector 253b. A power cable or the like that supplies the power supplied from a power source (not shown) to the electromagnetic valve, the motor of the drive unit 212b, etc. is connected to the first power connector 254a and the second power connector 254b. The above-mentioned members of the switching unit 25 are modularized and provided on the main body wall portion 212c of the main body portion 212a of the transfer robot 21.

[0044] Also, as shown in FIGS. 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 the first connection path 213a and the second connection path 213b, respectively, and measures the pressure values of the first ventilation path 120 and the second ventilation path 130. Further, 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 result of the pressure measurement unit 215. As an example, the pressure measurement unit 215 measures the pressure value of the first ventilation path 120 before starting the transfer of the object to be transferred W. The control unit 26 controls the second switching unit 251b before starting the transfer of the object to be transferred W to shift the second ventilation path 130 to the blocked state. Further, when the pressure value of the first ventilation path 120 measured by the pressure measurement unit 215 is equal to or less than a predetermined value, the control unit 26 controls the second switching unit 251b to shift the second ventilation path 130 to the suction state (details will be described in the transfer method of the object to be transferred W described later). Thereby, the object to be transferred W can be attracted to the first pad 140 and the second pad 150 by the second pad 150 having a greater suction force than the first pad 140. Further, the pressure measurement unit 215 may be able to measure the pressure value of the second ventilation path 130 in addition to the pressure value of the first ventilation path 120. Thereby, the control of the first switching unit 251a or the second switching unit 251b of the control unit 26 does not necessarily have to be controlled based on the pressure value of the first ventilation path 120 and may be adjusted as necessary. 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 ventilation path 120.

[0045] As can be understood from the above, the hand 100 of the present embodiment and the transfer device 20 to which the hand 100 is attached include a first pad 140 communicating with the first ventilation path 120 and a second pad 150 communicating with the second ventilation path 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 greater force to attract the object to be transferred W to the hand 100 than the first pad 140. On the other hand, in the adsorption and holding of the object to be transferred W, when a gap is generated between the second adsorption surface 156 and the object to be transferred W, the second pad 150 has a proportionally larger inflow of air from the gap due to its large 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 to attract the object to be transferred W to the hand 100 than the second pad 150. On the other hand, in the adsorption and holding of the object to be transferred W, when a gap is generated between the first adsorption surface 146 and the object to be transferred W, the first pad 140 has a proportionally smaller inflow of air from the gap due to its small suction volume. Due to the above differences in characteristics, the second pad 150 is advantageous for attracting the object to be transferred W and bringing the object to be transferred W into close contact with the first pad 140 and the second pad 150, and the first pad 140 is advantageous for stably adsorbing and holding the object to be transferred W. Note that the holding force of the object to be transferred W by the hand 100 depends on the total area of the adsorption surfaces of the pads that are adsorbing when the performance (vacuum reach) of the vacuum source V is equal. In the present embodiment, by ensuring a sufficient area of the first adsorption surface 146 that can stably adsorb and hold, the holding force required for the transfer of the object to be transferred W is ensured. Therefore, even when the suction volume (suction force) of the second pad 150 is set to 0 (the second ventilation path 130 is in a blocked state) so that the inflow of air from the second pad 150 does not affect the adsorption and holding of the object to be transferred W by the first pad 140, the object to be transferred W can be adsorbed and held only by the first pad 140.

[0046] According to the present embodiment, even if any one of the plurality of first pads 140 becomes non-contact with the workpiece W due to the warp of the workpiece W, since the suction amount of the first pad 140 during suction is small, the amount of air flowing in from the gap between the workpiece W and the non-contact first pad 140 is small. Therefore, a decrease in the holding force for adsorbing and holding the workpiece W is suppressed. The number of installed first pads 140, the area of the first adsorption surface 146, and the suction amount (the area S2 of the first inflow portion 149) are set so that a sufficient holding force for transporting the workpiece W is generated even when any number of first pads 140 are non-contact with the workpiece W. Further, even if any one of the plurality of second pads 150 becomes non-contact with the workpiece W due to the warp of the workpiece W, since the suction amount of the second pad 150 during non-suction is 0, air does not flow in from the gap between the workpiece W and the non-contact second pad 150, and the holding force of the first pad 140 for adsorbing and holding the workpiece W does not decrease. Thereby, the hand 100 of the present embodiment and the transfer device 20 to which the hand 100 is attached can surely adsorb and hold the workpiece W while suppressing the inflow of air from the gap between the non-contact pad and the workpiece W and ensuring sufficient suction force of the pad even if the workpiece W warps.

[0047] The method of transporting the workpiece W by the transfer device 20 including the hand 100 of the present embodiment will be described with reference to the following two examples.

[0048] Referring to FIGS. 1 to 5 and FIG. 12, a method for transporting the object to be transported W using the transport device 20 having the above-described hand 100 in the first embodiment will be described for each step. The method for transporting the object to be transported W is a method for transporting by the transport device 20 including the hand 100 for holding the object to be transported W, and mainly includes a start step S11, a suction step S12, a shut-off step S13, a determination step S14, a transport step S15, and a confirmation step S16. In the start step S11, preliminary work for sucking the object to be transported 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 shifted to the suction state, and the object to be transported 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 shut-off step S13, after the object to be transported W is adsorbed and held, the second air passage 130 communicating with the second pad 150 is shifted to the shut-off state. In the determination step S14, when it is determined that the pressure value of the first air passage 120 exceeds a predetermined value, the process proceeds to the transport step S15, and when it is determined that the pressure value of the first air passage 120 is equal to or less than the predetermined value, the process returns to the suction step S12 again. In the transport step S15, the object to be transported W is transported to a predetermined position. In the confirmation step S16, it is confirmed whether or not to continue the transport of the object to be transported W. If there is an object to be transported W to be transported, the process returns to the start step S11 again. If there is no object to be transported W to be transported, the transport of the object to be transported W is terminated. According to this transport method, the transport device 20 including the hand 100 can transport the object to be transported W from the slot of the container H or the mounting table of the processing device 60 to another place while the object to be transported W is adsorbed and held by the hand 100. Note that the determination step S14 and the confirmation step S16 may be omitted.

[0049] Specifically, in the present 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 to transfer the object to be transferred 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 until the transfer of the object to be transferred W is completed (for example, a transfer completion signal is received), and the communication state of the first air passage 120 and the second air passage 130 is switched by the switching unit 25. Subsequently, in the transfer robot moving step S112, when the transfer device 20 receives, for example, a movement start signal, it controls the operations of the guide structure 23 and the robot arm 211, and moves the transfer robot 21 so that the hand 100 of the transfer robot 21 is positioned below the object to be transferred W. During this movement, the transfer device 20 turns off the first switching unit 251a and the second switching unit 251b, shifts the first air passage 120 and the second air passage 130 to the blocked state respectively, and sets the suction amounts (suction forces) of the first pad 140 and the second pad 150 to 0. Thereby, it is possible to avoid sucking the object to be transferred W at an unexpected position. When the hand 100 is inserted below the object to be transferred W in the transfer robot moving step S112, the preliminary work for sucking the object to be transferred W is completed, and the process proceeds to the suction step S12.

[0050] Next, after inserting the hand 100 below the object W to be conveyed in the conveying robot movement step S112, in the suction step S12, the conveying device 20 receives, for example, a holding start signal and drives the switching unit 25 to change the communication state. Specifically described, in the suction step S12, the conveying device 20, for example, turns on the first switching unit 251a and the second switching unit 251b, shifts the first air passage 120 and the second air passage 130 to the suction state, and sucks the object W to be conveyed by 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 the present 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 common to adsorb while attracting the object W to be conveyed. Thereby, 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 a suction force and adsorb the object W to be conveyed while attracting it from below the object W to be conveyed. As an example, the holding start signal is automatically transmitted after the conveying robot 21 reaches the target position for conveying the object W to be conveyed (after the hand 100 of the conveying robot 21 reaches the position below the object W to be conveyed).

[0051] Next, after the conveyed object W is sucked by the first pad 140 communicating with the first ventilation path 120 and the second pad 150 communicating with the second ventilation path 130 in the suction step S12, the process proceeds to the blocking step S13. In the present embodiment, the blocking step S13 includes a suction standby step S131 and a second ventilation path blocking step S132. First, in the suction standby step S131, the conveying device 20 continues the suction states of the first ventilation path 120 and the second ventilation path 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 to this, and the suction standby step S131 may be completed without waiting for the elapse of the predetermined time, but rather when at least the first pad 140 has adsorbed and held the conveyed object W. In this case, for example, it may be determined that the first pad 140 has adsorbed and held the conveyed object W when the pressure value of the first ventilation path 120 measured by the pressure measurement unit 215 reaches a predetermined value. Thereafter, in the second ventilation path blocking step S132, the control unit 26 receives, for example, the second switching unit blocking signal, turns off the second switching unit 251b, and shifts the second ventilation path 130 to the blocked state. That is, the conveyed object W is adsorbed and held only by the first pad 140 with the suction by the second pad 150 communicating with the second ventilation path 130 stopped. Note that the suction state of the second ventilation path 130 is further measured by the pressure measurement unit 215, and when the pressure values of the first ventilation path 120 and the second ventilation path 130 have reached the predetermined values, the suction by the second pad 150 may be continued. That is, the second ventilation path blocking step S132 is skipped, and the conveyed object W is adsorbed and held by the first pad 140 and the second pad 150. In this case, with the suction by the second pad 150 continued, after passing through the determination in the determination step S14 described later, the process proceeds to the conveyance step S15. As an example, the second switching unit blocking signal is automatically transmitted to the control unit 26 after a predetermined time has elapsed since the transmission of the holding start signal to the control unit 26 (that is, after the suction standby step S131 has been executed). As another example, the second switching unit blocking signal may be transmitted to the control unit 26 when the pressure value of the first ventilation path 120 measured by the pressure measurement unit 215 has reached a predetermined value.

[0052] Next, after shifting the second air passage 130 to the blocked state in the blocking step S13, the process proceeds to the conveying step S15. Specifically, in the present embodiment, a determination step S14 performed between the blocking step S13 and the conveying step S15 is further included. In the determination step S14, when it is determined that the pressure value of the first air passage 120 exceeds a predetermined value, the process proceeds to the conveying step S15, and when it is determined that the pressure value of the first air passage 120 is equal to or less than the predetermined value, the process returns to the suction step S12 again. In this process, the conveying device 20 receives, for example, a pressure value measurement signal, measures the pressure value of the first air passage 120 using the pressure measurement unit 215 provided in the conveying robot 21 shown in FIG. 1, and makes a determination based on the predetermined value by the control unit 26. When it is determined that the pressure value of the first air passage 120 exceeds the predetermined value, it indicates that the adsorption and holding of the object to be conveyed W by only the first pad 140 communicating with the first air passage 120 is sufficient. Since the object to be conveyed W can be surely adsorbed and held during the conveying process, the process proceeds to the conveying step S15 (transmits a conveying start signal). On the other hand, when it is determined that the pressure value of the first air passage 120 is equal to or less than the predetermined value, it indicates that the adsorption and holding of the object to be conveyed W by only the first pad 140 communicating with the first air passage 120 is not sufficient. Since there is a possibility that the object to be conveyed W cannot be surely adsorbed and held during the conveying process, the process returns to the suction step S12 again (transmits a suction start signal). When shifting to the suction step S12, the suction of the first pad 140 and the second pad 150 is stopped. As an example, the pressure value measurement signal is automatically transmitted after a predetermined time has elapsed since the transmission of the second switching unit blocking signal, or is transmitted after receiving the second switching unit blocking completion signal.

[0053] Next, after shifting the second ventilation path 130 to the blocked state in the blocking step S13 and after it is determined in the determination step S14 that the pressure value of the first ventilation path 120 exceeds a predetermined value, the process proceeds to the transfer step S15. Specifically, in the present embodiment, the transfer step S15 includes a transfer robot transfer step S151 and a first ventilation path 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 object W to be transferred to a predetermined position (for example, another slot of the container H or a mounting table of the processing device 60). Subsequently, in the first ventilation path blocking step S152, after transferring the object W to be transferred to the predetermined position, the control unit 26 receives, for example, a first switching unit blocking signal or an adsorption holding completion signal, turns off the first switching unit 251a, and shifts the first ventilation path 120 to the blocked state. That is, all the ventilation paths and pads are turned off, and the adsorption and holding of the object W to be transferred are completed. As an example, the first switching unit blocking signal or the adsorption holding completion signal is automatically transmitted after the transfer robot 21 transfers the object W to be transferred to the predetermined position. After the object W to be transferred is transferred to the predetermined position in the transfer step S15 (for example, after the object W to be transferred is placed in the slot of the container H), in order to safely remove the object W from the hand 100, a release valve (not shown) may be opened to release the adsorption and holding by the first pad 140 and / or the second pad 150.

[0054] Finally, after the conveyed object W is conveyed to a predetermined position in the conveying step S15, the process proceeds to the confirmation step S16. Specifically, in the present embodiment, the confirmation step S16 includes a remaining quantity confirmation step S161 and a vacuum source stop step S162. First, in the remaining quantity confirmation step S161, after the conveyed object W is conveyed to a predetermined position, the control unit 26 receives, for example, a remaining quantity confirmation signal and checks whether there is a next conveyed object W to be conveyed by the conveying device 20 or the number thereof. That is, it is checked whether to continue conveying the next conveyed object W using the conveying robot 21 provided in the conveying device 20. When the control unit 26 confirms that there is a next conveyed object W, the process proceeds to the conveying robot movement step S112 of the start step S11 again (sends a movement start signal), and the above-described suction step S12, blocking step S13, determination step S14, and conveying step S15 are executed. When the control unit 26 confirms that there is no next conveyed object W, the process proceeds to the vacuum source stop step S162. In the vacuum source stop step S162, the conveying device 20 receives, for example, a conveyance completion signal, turns off the vacuum source V, and the conveyance of the conveyed object W ends. As an example, the conveyance completion signal is automatically transmitted when it is confirmed that the conveyance of all the conveyed objects W is completed.

[0055] As can be seen from this, the hand 100 attached to the conveying device 20 used in the conveying method of the object W to be conveyed in the present 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, since the second pad 150 has a larger air suction amount per unit time than the first pad 140, the second pad 150 is advantageous for attracting the object W to be conveyed and bringing the object W to be conveyed into close contact with the first pad 140 and the second pad 150. The first pad 140 is advantageous for stably adsorbing and holding the object W to be conveyed. In the present embodiment, in the suction step S12, in order to promote the adsorption of the object W to be conveyed by the first pad 140, the first air passage 120 and the second air passage 130 are shifted to the suction state, and the object W to be conveyed is attracted to the first pad 140 by the suction force from the first pad 140 and the second pad 150 (mainly the suction force from the second pad 150 with a large suction amount). Further, after the object W to be conveyed is adsorbed and held by the first pad 140, the second air passage 130 is shifted to the blocked state so that the inflow of air from the second pad 150 does not affect the adsorption and holding of the object W to be conveyed by the first pad 140. Since no air inflow occurs from the second pad 150 where the suction amount (suction force) has become zero, the first pad 140 can stably adsorb and hold the object W to be conveyed. In this way, even if any one of the plurality of first pads 140 becomes non-contact with the object W to be conveyed due to the warping of the object W to be conveyed, the amount of air flowing in from the gap between the non-contact first pad 140 and the object W to be conveyed is small, so that a decrease in the holding force for adsorbing and holding the object W to be conveyed is suppressed. Further, when the object W to be conveyed is being conveyed, since the second air passage 130 is shifted to the blocked state, even if a gap is generated between the object W to be conveyed and the second pad 150, no air flows in from the gap, and the holding force of the first pad 140 for adsorbing and holding the object W to be conveyed does not decrease. Thereby, the conveying method of the object W to be conveyed in the present embodiment can surely adsorb and hold the object W to be conveyed while suppressing the inflow of air from the gap between the non-contact pad and the object W to be conveyed and ensuring sufficient suction force of the pad even if the object W to be conveyed warps.

[0056] Next, with reference to FIGS. 1 to 6 and FIG. 12, a method for transporting the object to be transported W using the transport device 20 including the hand 100 in the second embodiment will be described for each step. The method for transporting the object to be transported W is a method for transporting by the transport device 20 including the hand 100 that holds the object to be transported 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 shut-off step S23 (including a suction standby step S231 and a second air passage shut-off step S232), a determination step S24, a transport step S25 (including a transport robot transport step S251 and a first air passage shut-off 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 the same as those in the first embodiment described above, and thus the description thereof is omitted. Note that the determination step S24 and the confirmation step S26 may be omitted.

[0057] In the attracting 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 ventilation path 120 and the second ventilation path 130. Specifically described, the attracting step S22 of the second embodiment includes a first attracting step S221 and a second attracting step S222, which is different from the attracting step S12 of the first embodiment. In the first attracting step S221, the control unit 26 receives, for example, a holding start signal, turns off the first switching unit 251a, shifts the first ventilation path 120 to a blocked state, and when the first ventilation path 120 is in the blocked state, turns on the second switching unit 251b, shifts the second ventilation path 130 to an attracting state, and attracts the object to be conveyed W by the second pad 150 communicating with the second ventilation path 130. Further, in the second attracting step S222, the control unit 26, for example, after waiting for a predetermined time, in a state where the object to be conveyed W is attracted or adsorbed by the second ventilation path 130 in the attracting state, turns on the first switching unit 251a, shifts the first ventilation path 120 to the attracting state, and attracts the object to be conveyed W by the first pad 140 communicating with the first ventilation path 120 so as to hold it. That is, in the present embodiment, the second pad 150 communicating with the second ventilation path 130 and the first pad 140 communicating with the first ventilation path 120 are used in turn, and the object to be conveyed W is attracted and then adsorbed. Thereby, the first pad 140 communicating with the first ventilation path 120 and the second pad 150 communicating with the second ventilation path 130 can generate an attractive force to attract the object to be conveyed W from below the object to be conveyed W and then adsorb it.

[0058] In this embodiment, in the suction step S12, the pulling of the object to be conveyed W by the second pad 150 (first suction step S221) and the adsorption and holding of the object to be conveyed W by the first pad 140 (second suction step S222) are executed in order. In the first suction step S221, only the second air passage 130 among the first air passage 120 and the second air passage 130 communicating with the same vacuum source V is shifted to the suction state, and a suction force is generated only from the second pad 150. Since the suction force of the vacuum source V is not dispersed as compared with the case where both the first air passage 120 and the second air passage 130 are in the suction state, a sufficient suction force is generated in the second pad 150. Therefore, the object to be conveyed W can be surely pulled toward the second pad 150 side. Further, in the second suction step S222, in the first suction step S221, the first air passage 120 is shifted to the suction state while the object to be conveyed W is being pulled toward the second pad 150 side. In the state where the object to be conveyed W is pulled toward the second pad 150 side, since the object to be conveyed W is also close to the first pad 140, the object to be conveyed W can be surely adsorbed and held by the suction force from the first pad 140. Thus, in the conveying method of the object to be conveyed W of this embodiment, since the object to be conveyed W can be sufficiently pulled by the second pad 150 having a large suction force, even the first pad 140 having a small suction force can adsorb and hold the object to be conveyed W. Further, even if the object to be conveyed W is warped, while suppressing the inflow of air from the gap between the non-contact pad and the object to be conveyed W, a sufficient suction force of the pad can be ensured to surely adsorb and hold the object to be conveyed W.

[0059] In summary, the hand of the present invention is provided with a first suction system formed by a first ventilation passage and a first pad communicating therewith, and a second suction system formed by a second ventilation passage and a second pad communicating therewith, and sucks an object to be conveyed by different suction amounts. When conveying an object to be conveyed using a hand provided with a first pad and a second pad having different suction amounts, the object to be conveyed is surely attracted to the upper surface of the hand by the one with the larger suction amount (i.e., the second pad), and the object to be conveyed is surely adsorbed and held only by the one with the smaller suction amount (i.e., the first pad). For example, the object to be conveyed is attracted by at least the second pad with a large suction amount, and the object to be conveyed is adsorbed and held only by the first pad with a small suction amount (the second ventilation passage is shifted to a blocked state), and the object to be conveyed is conveyed. Thereby, even if the object to be conveyed is warped, while suppressing the inflow of air from the gap between the non-contact first pad or second pad and the object to be conveyed, the suction force of the first pad is sufficiently ensured, and the object to be conveyed can be surely adsorbed and held.

[0060] Finally, it should be noted that the above embodiments are only used for explaining the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can naturally understand that the technical solutions described in the above embodiments can still be modified, or equivalent replacements can be made for some or all of the technical features. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Industrial Applicability

[0061] The hand of the present invention, a conveying device equipped with the hand, and a method for conveying an object to be conveyed using the conveying device can surely adsorb and hold the object to be conveyed while suppressing the inflow of air from the gap between the non-contact pad and the object to be conveyed and ensuring sufficient suction force of the pad even if the object to be conveyed is warped.

Explanation of Reference Numerals

[0062] 20 Transfer device, 21 Transfer 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 part, 112 Base, 114 Hand part, 114a;141a;142a;143a;151a;152a Upper surface, 114b;142b;152b;160a Lower surface, 114c Pedestal part, 114d Groove part, 1141 First finger part, 1142 Second finger part, 115 Cover, 116 Installation part, 1161 First installation part, 1162 Second installation part, 1161a;1162a Large diameter part, 1161b;1162b Small diameter part, 1161c;1162c Connection part, 1162 Second installation part, 120 First ventilation path, 122 First ventilation part, 124 First communication part, 126 First connection hole, 130 Second ventilation path, 132 Second ventilation part, 134 Second communication part, 136 Second connection hole, 140;140A First pad, 141 First extended part, 142 First engaging part,, 142c;152c Outer peripheral surface, 142d;152d Inner peripheral surface, 143 First contact part, 144 First extending part, 144a First base end part, 144b First tip part, 144c First jaw part, 146 First adsorption surface, 148 First suction space, 149 First inflow part, 150 Second pad, 151 Second extended part, 152 Second engaging part, 154 Second extending part, 154a Second base end part, 154b Second tip part, 154c Second jaw part, 156 Second adsorption surface, 158 Second suction space, 159 Second inflow part, 160 Throttle member, 162 Through hole, 211 Robot arm, 212a Main body part, 212b Driving part, 212c Main body wall part, 213 Connection part, 213a First connection path, 213b Second connection path, 214 Suction path, 215 Pressure measurement part, 251a First switching part, 251b Second switching part, 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;S22 Suction process, S13;S23 Shut-off process, S131; S231 Suction standby process, S132; S232 Second air passage shut-off process, S14; S24 Judgment process, S15; S25 Conveying process, S151; S251 Conveying robot conveying process, S152; S252 First air passage shut-off process, S16; S26 Confirmation process, S161; S261 Remaining quantity confirmation process, S162; S262 Vacuum source stop process, S221 First suction process, S222 Second suction process, V Vacuum source, W Object to be conveyed;

Claims

1. A hand mounted on a conveying device for holding an object to be conveyed, comprising: a hand body; a first ventilation passage connected to a vacuum source; a second ventilation passage connected to the vacuum source; a first pad communicating with the first ventilation passage and adsorbing the object to be conveyed; a second pad communicating with the second ventilation passage and sucking the object to be conveyed, wherein a plurality of the first pads and the second pads are provided on the hand body; the suction amount of the first pad is smaller than that of the second pad; the hand body further comprises a first installation portion where the first pad is installed and a second installation portion where the second pad is installed; the first pad has a hollow shape, a first engaging portion engaging with the first installation portion, a first extending portion extending from the first engaging portion, and a first through hole communicating with the first ventilation passage; the second pad has a hollow shape, a second engaging portion engaging with the second installation portion, a second extending portion extending from the second engaging portion, and a second through hole communicating with the second ventilation passage. A hand characterized by the above.

2. A plurality of the first installation portion and the second installation portion are provided on the hand body. The hand according to claim 1, characterized by the above.

3. The second extending portion is configured to be displaceable between a first position where an end of the second extending portion is spaced from an upper surface of the hand body more than an end of the first extending portion and a second position where the end of the second extending portion approaches the upper surface of the hand body more than the end of the first extending portion. The hand according to claim 1 or 2, characterized by the above.

4. A hand mounted on a conveying device for holding an object to be conveyed, comprising: a hand body; a first ventilation passage connected to a vacuum source; a second ventilation passage connected to the vacuum source; a first pad communicating with the first ventilation passage and adsorbing the object to be conveyed; a second pad communicating with the second ventilation passage and sucking the object to be conveyed, wherein a plurality of the first pads and the second pads are provided on the hand body; the suction amount of the first pad is smaller than that of the second pad; the first pad has a hollow shape, a first suction space into which internal air is sucked, and a first through hole communicating the first suction space with the first ventilation passage; the second pad has a hollow shape, a second suction space into which internal air is sucked, and a second through hole communicating the second suction space with the second ventilation passage; the area of the first through hole is smaller than the area of the second through hole. A hand characterized by the above.

5. Further comprising a throttle member inserted into the first through hole, the throttle member has a through hole with an area smaller than the area of the first through hole, the first pad includes a defining portion that defines the insertion position of the throttle member inserted into the first through hole The hand according to claim 4, characterized in that.

6. A hand mounted on a transfer device for holding an object to be transferred, a hand body, a first ventilation path connected to a vacuum source, a second ventilation path connected to the vacuum source, a first pad communicating with the first ventilation path and adsorbing the object to be transferred, a second pad communicating with the second ventilation path and sucking the object to be transferred, and a plurality of the first pads and the second pads are provided on the hand body, the suction amount of the first pad is smaller than that of the second pad, the hand body, a base portion provided with a first connection hole connecting the first ventilation path and the vacuum source and a second connection hole connecting the second ventilation path and the vacuum source, and a hand portion including a first finger portion and a second finger portion extending bifurcated from the base portion, the first finger portion is provided with the first pad and the second pad, the second finger portion is provided with the first pad and the second pad A hand characterized by that.

7. A hand mounted on a transfer device for holding an object to be transferred, a hand body, a first ventilation path connected to a vacuum source, a second ventilation path connected to the vacuum source, a first pad communicating with the first ventilation path and adsorbing the object to be transferred, a second pad communicating with the second ventilation path and sucking the object to be transferred, and a plurality of the first pads and the second pads are provided on the hand body, the suction amount of the first pad is smaller than that of the second pad, the hand body has an inner side close to a reference point located on a center line extending along the extending direction of the hand body and an outer side away from the reference point, the second pad is provided on the hand body closer to the inner side than the first pad A hand characterized by that.

8. A hand mounted on a transfer device for holding an object to be transferred, a hand body, a first ventilation path connected to a vacuum source, a second ventilation path connected to the vacuum source, a first pad communicating with the first ventilation path and adsorbing the object to be transferred, a second pad communicating with the second ventilation path and sucking the object to be transferred, and A plurality of the first pads and the second pads are provided on the hand body. The first pad has a smaller suction amount than the second pad. The hand body has an inner side close to a reference point located on a center line extending along the extending direction of the hand body and an outer side away from the reference point. The first air passage and the second air passage are formed at different positions of the hand body so as not to communicate with each other, and the first air passage is formed on the outer side rather than the second air passage. A hand characterized by the above.

9. A hand for holding an object to be conveyed, A transfer 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, A control unit that controls the switching unit, and the hand is 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 to be conveyed, a second pad that communicates with the second air passage and sucks the object to be conveyed, and a plurality of the first pads and the second pads are provided on the hand body, the first pad has a smaller suction amount than the second pad, the switching unit includes 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, the switching unit switches the communication state between a suction state in which the suction force of air by the vacuum source is exerted and a cutoff state in which the suction force of air by the vacuum source is not exerted, before starting the conveyance of the object to be conveyed, the control unit controls the second switching unit to shift the second air passage to the cutoff state. A transfer device characterized by the above.

10. The transfer device further includes a pressure measurement unit that measures the pressure value of the first air passage. When the pressure value of the first air passage measured by the pressure measurement unit is equal to or less than a predetermined value, the control unit controls the second switching unit to shift the second air passage to the suction state. The transfer device according to claim 9, characterized by the above.

11. A method for conveying an object to be conveyed by a transfer device including a hand for holding the object to be conveyed, The hand includes a hand body, a first ventilation passage connected to a vacuum source, a second ventilation passage connected to the vacuum source, a first pad communicating with the first ventilation passage and adsorbing the object to be conveyed, and a second pad communicating with the second ventilation passage and sucking the object to be conveyed. A plurality of the first pads and the second pads are provided on the hand body. The suction amount of the first pad is smaller than that of the second pad. The method for conveying the object to be conveyed is as follows. A suction step of sucking the object to be conveyed by the first pad communicating with the first ventilation passage and the second pad communicating with the second ventilation passage. A blocking step of shifting the second ventilation passage to a blocked state after adsorbing and holding the object to be conveyed. A conveying step of conveying the object to be conveyed to a predetermined position. including A method for conveying an object to be conveyed, characterized in that it is as described above.

12. The suction step includes a first suction step and a second suction step. In the first suction step, when the first ventilation passage is in a blocked state, the second ventilation passage is shifted to a suction state, and the object to be conveyed is sucked by the second pad so as to be attracted. In the second suction step, while the object to be conveyed is being adsorbed by the second ventilation passage in a suction state, the first ventilation passage is shifted to a suction state, and the object to be conveyed is sucked by the first pad so as to be held. The method for conveying an object to be conveyed according to claim 11, characterized in that it is as described above.

13. The method further includes a determination step performed between the blocking step and the conveying step. In the determination step, when it is determined that the pressure value of the first ventilation passage exceeds a predetermined value, the process proceeds to the conveying step. When it is determined that the pressure value of the first ventilation passage is equal to or less than the predetermined value, the process proceeds to the suction step again. The method for conveying an object to be conveyed according to claim 12, characterized in that it is as described above.

14. A hand mounted on a conveying device for holding an object to be conveyed, comprising: a hand body; a first ventilation passage connected to a vacuum source; a second ventilation passage connected to the vacuum source; a first pad communicating with the first ventilation passage and adsorbing the object to be conveyed; a second pad communicating with the second ventilation passage and sucking the object to be conveyed; a throttle member for making the suction amount of the first pad smaller than the suction amount of the second pad. A plurality of the first pads and the second pads are provided on the hand body. The first pad has a hollow shape and has a first suction space in which internal air is sucked, and a first through hole communicating the first suction space with the first ventilation passage. The second pad has a hollow shape, and has a second suction space into which air inside is sucked, and a second through-hole that communicates with the second suction space and the second ventilation path. The throttle member has a through-hole with an area smaller than the area of the first through-hole. A hand characterized by this.

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