Suction pad and article-holding device

Abstract

In order to improve suction properties over articles, a suction pad (1) comprises: a vacuum part (2) including one end (2a) to be connected to a pad attachment (102); a suction part (3) comprising a first suction part (3a), which is connected to the other end (2b) of the vacuum part (2) and increases in diameter outward from the vacuum part (2), and a second suction part (3b), which is folded back from the first suction part (3a) toward the pad attachment (102) side and increases in diameter outward from the first suction part (3a); and a shape maintenance part (4) for maintaining the shape of the second suction part (3b) when an article is not suction-held.

Description

Suction pad and article holding device

[0001] The present disclosure relates to a suction pad and an article holding device.

[0002] In recent years, picking devices (transfer devices) have been used in factories, warehouses, etc., for example, to efficiently sort and select large quantities of various items according to their shipping destinations. Such picking devices are equipped with suction pads for suctioning an item (object to be attracted), and are configured to transfer the item to a desired position while the item is attracted by the suction pad.

[0003] With regard to this type of suction pad, Patent Document 1 discloses a suction pad in which a contact portion that comes into contact with an article is provided with elastic petal-shaped portions separated by a plurality of recesses.

[0004] Japanese Patent Application Publication No. 2020-89936

[0005] However, the above-mentioned conventional suction pads have room for improvement in terms of their ability to adsorb articles.

[0006] An object of the present disclosure is to provide a suction pad and an article holding device that can improve the suction performance for an article.

[0007] In order to solve the above problems, an suction pad according to one aspect of the present disclosure is an suction pad that is attached to a pad attachment portion provided with a suction port of an article holding device that holds an article, and includes: a bellows-shaped suction portion having one end connected to the pad attachment portion; an suction portion that is connected to the other end of the suction portion opposite the one end and that adsorbs to an article, the suction portion having a first suction portion that is connected to the other end of the suction portion and that expands in diameter as it moves away from the suction portion; and a second suction portion that is folded back from the first suction portion toward the pad attachment portion and that expands in diameter as it moves away from the first suction portion; and a shape retention portion that is connected to the second suction portion side of the suction portion, is arranged around the suction portion, and maintains the shape of the second suction portion when the article is not being adsorbed.

[0008] Moreover, an article holding device according to one aspect of the present disclosure is an article holding device having a pad mounting portion provided with a suction port, and is equipped with an suction pad including: a bellows-shaped suction portion having one end connected to the pad mounting portion; an suction portion connected to the other end of the suction portion opposite the one end and adapted to adsorb to an article, the suction portion having a first suction portion connected to the other end of the suction portion and expanding in diameter as it moves away from the suction portion; and a second suction portion folded back from the first suction portion toward the pad mounting portion and expanding in diameter as it moves away from the first suction portion; and a shape retaining portion connected to the second suction portion side of the suction portion and arranged around the suction portion, which retains the shape of the second suction portion when the article is not being adsorbed.

[0009] According to one aspect of the present disclosure, it is possible to provide a suction pad and an article holding device that can improve the suction performance for an article.

[0010] FIG. 1 is a perspective view showing an example of the configuration of a main part of a suction pad according to a first embodiment of the present disclosure and an article holding device using the same; FIG. 2 is a cross-sectional end view illustrating an example of the configuration of a main part of the suction pad; FIG. 3 is a cross-sectional end view illustrating an example of the operation of the suction pad; FIG. 4 is a cross-sectional end view illustrating another example of the operation of the suction pad; FIG. 5 is a cross-sectional end view illustrating an example of the configuration of a main part of a suction pad and a pad attachment part according to a second embodiment of the present disclosure and an example of the operation; FIG. 6 is a cross-sectional end view illustrating an example of the configuration of a main part of a modified example of the pad attachment part shown in FIG. 5; and FIG. 7 is a cross-sectional end view illustrating an example of the configuration of a main part of a suction pad according to modified examples 1 and 2.

[0011] 1 to 4. In the following description, a suction pad and an article holding device according to the present disclosure are applied to a transfer device (picking device), such as a five-axis robot, that transfers an article to a desired position. However, the following description is an example of a suction pad and an article holding device according to the present disclosure, and the technical scope of the present disclosure is not limited to the illustrated example.

[0012] (Configuration of the article holding device) First, a configuration example of the suction pad 1 according to the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing a configuration example of the main parts of the suction pad 1 according to the first embodiment of the present disclosure and an article holding device 100 using the same. Fig. 2 is a cross-sectional end view illustrating the configuration example of the main parts of the suction pad 1.

[0013] As shown in Fig. 1, the article holding device 100 of the first embodiment includes a base 101 and a pad mounting portion 102. Furthermore, as shown in Fig. 1, the article holding device 100 is provided with a plurality of, for example, three, suction pads 1. Each of the three suction pads 1 of the present disclosure is attached to the base 101 via a pad mounting portion 102. Furthermore, each of the three pad mounting portions 102 is provided with a suction port 102a for sucking air and a cylindrical mounting member 102b. Furthermore, the article holding device 100 is provided with a vacuum pump (not shown) and is configured to suck air through the suction port 102a.

[0014] The suction pad 1 is attached to the attachment member 102b by fitting a suction portion (described later) of the suction pad 1 into the outer peripheral surface of the attachment member 102b protruding from the surface of the pad attachment portion 102 on the opposite side from the base 101. In the article holding device 100, a vacuum is drawn from the suction port 102a corresponding to the suction pad 1 pressed against the article, causing the suction pad 1 to elastically deform and suck and hold the article.

[0015] The base 101 also constitutes the base of the picking head of the picking device. The base 101 has a hole 103a through which a tilt shaft provided in a tilt mechanism (not shown) is inserted, and a support part 103 for rotatably supporting the tilt shaft inserted into the hole 103a is provided on the opposite side from the pad mounting part 102.

[0016] A rotation mechanism (not shown) having a rotation axis for rotating the picking head is connected via the tilt axis to the base 101. The article holding device 100 is equipped with the five-axis robot (five axes: X, Y, and Z direction axes + picking head rotation axis + picking head tilt axis), and is configured to appropriately pick up an article with at least one suction pad 1 and further hold and transfer the article by appropriately changing the positions of the three suction pads 1 with the five-axis robot.

[0017] 2, the suction pad 1 of the first embodiment includes a suction portion 2, a suction portion 3, and a shape-retaining portion 4. Furthermore, when the suction pad 1 is not suctioning an article (when an article is not being suctioned), the shape-retaining portion 4 (described below) of the suction pad 1 is configured not to come into contact with the pad attachment portion 102. In other words, in the suction pad 1, the shape-retaining portion 4 is in a floating state with respect to the pad attachment portion 102 when an article is not being suctioned.

[0018] (Configuration of Suction Unit) The suction unit 2 is made of, for example, an elastically deformable resin material such as silicone resin. The suction unit 2 is formed, for example, in a bellows-like shape, with one ring-shaped end 2a connected to the pad mounting unit 102. Specifically, the one end 2a of the suction unit 2 is fitted from the outside to the outer circumferential surface of the mounting member 102b. In this way, the suction unit 2 is connected to the pad mounting unit 102, and the suction pad 1 is mounted to the pad mounting unit 102.

[0019] In the suction part 2, an opening 2c that is circular in plan view seen from the pad mounting part 102 side is formed at the other end 2b of the ring shape, which is opposite to the pad mounting part 102. The opening 2c serves as an air suction port for the suction pad 1.

[0020] (Configuration of Adsorption Portion) The adsorption portion 3 is made of an elastically deformable resin material such as silicone resin, and is configured to connect to the other end 2b of the suction portion 2 opposite to the one end 2a. Specifically, as shown in Fig. 2, the adsorption portion 3 has a first adsorption portion 3a that is connected to the other end 2b of the suction portion 2 and increases in diameter as it moves away from the suction portion 2, and a second adsorption portion 3b that is folded back from the first adsorption portion 3a toward the pad attachment portion 102 and increases in diameter as it moves away from the first adsorption portion 3a.

[0021] In other words, the suction portion 3 is composed of a first suction portion 3a and a second suction portion 3b, and has a folded portion 3c that is folded back toward the pad mounting portion 102 at the lower end position of the suction pad 1, for example.

[0022] In the suction portion 3, both the first suction portion 3a and the second suction portion 3b are made of an elastically deformable material. The folded portion 3c is configured in a ring shape when not suctioning an article. On the other hand, when suctioning an article, the folded portion 3c can be appropriately deformed from the ring shape in response to the elastic deformation of the first suction portion 3a and / or the elastic deformation of the second suction portion 3b (see, for example, FIG. 4 below).

[0023] In addition, an opening 3d is formed in the end of the suction part 3 on the side of the pad attachment part 102, opposite the folded part 3c. This opening 3d is sequentially connected to the opening 2c of the suction part 2 and the suction port 102a of the pad attachment part 102, so that when an article is to be sucked, the article can be sucked.

[0024] (Configuration of Shape-Retaining Part) The shape-retaining part 4 is made of, for example, the same material as the suction part 3. The shape-retaining part 4 is arranged around the suction part 2 and is configured to retain the shape of the second suction part 3b when the article is not being suctioned. The shape-retaining part 4 may be configured to have higher rigidity than the suction part 3.

[0025] Specifically, the shape-retaining portion 4 is made of the same elastically deformable resin material as the suction portion 3, such as silicone resin, and is formed integrally with the suction portion 3. As shown in Fig. 2, one ring-shaped end 4a of the shape-retaining portion 4 is connected to the second suction portion 3b side of the suction portion 3. The shape-retaining portion 4 is configured so that its diameter decreases as it moves away from the second suction portion 3b. The other end 4b of the shape-retaining portion 4 is formed in a ring shape configured to have a predetermined thickness in order to impart higher rigidity to the shape-retaining portion 4 than the suction portion 3.

[0026] Furthermore, the other end 4b of the shape-retaining part 4 is positioned away from the pad attachment part 102 when an article is not being adsorbed. As a result, as described above, when an article is not being adsorbed, the shape-retaining part 4 is in a floating state without contacting the pad attachment part 102. This allows the adsorption part 3 to more easily elastically deform in response to the article when the article is being adsorbed.

[0027] In the above description, the shape-retaining part 4 is made of the same material as the suction part 3. However, the shape-retaining part 4 of the present disclosure is not limited in any way as long as it can maintain the shape of the second suction part 3b when the article is not being suctioned, and the shape-retaining part 4 may be made of a material different from that of the suction part 3. Specifically, the shape-retaining part 4 may be made of a member such as a metal material, for example.

[0028] However, it is preferable to configure the shape-retaining portion 4 to have higher rigidity than the suction portion 3, in that when the suction portion 3 is not adsorbing an article, the shape-retaining portion 4 can reliably maintain the shape of the suction portion 3 in the initial shape exemplified in Fig. 2. In other words, when the suction portion 3 elastically deforms to adsorb an article and then releases the adsorption state of the article, the shape-retaining portion 4 is preferable in that it has higher rigidity than the suction portion 3 and can reliably restore the shape of the second suction portion 3b, and therefore the shape of the suction portion 3, to the shape before adsorption (initial shape).

[0029] (Example of operation of suction pad) Next, an example of operation of the picking head equipped with the suction pad 1 of the first embodiment will be specifically described with reference to Fig. 3 and Fig. 4. Fig. 3 is a cross-sectional end view illustrating an example of operation of the suction pad 1. Fig. 4 is a cross-sectional end view illustrating another example of operation of the suction pad 1.

[0030] As shown in Fig. 3 , in the suction pad 1, the suction portion 3 suctions the rectangular parallelepiped-shaped article B1 so that the opening 3d of the suction portion 3 includes the upper surface of the article B1. In this case, the first suction portion 3a and the second suction portion 3b of the suction portion 3 elastically deform along the left and right sides of the article B1 so as to come into close contact with the respective side surfaces. In the suction pad 1, the suction portion 3 suctions the article B1 by vacuuming through the opening 3d, as shown by arrow F1 in Fig. 3 , and can lift the article B1 upward.

[0031] As shown in Fig. 4 , in the suction pad 1, the suction portion 3 suctions the rectangular parallelepiped-shaped article B2 so that the opening 3d of the suction portion 3 includes the top surface and left side surface of the article B2. In this case, the first suction portion 3a and the second suction portion 3b of the suction portion 3 elastically deform so as to fit closely to the top surface and left side surface of the article B2. In the suction pad 1, the suction portion 3 suctions the article B2 by vacuuming through the opening 3d, as shown by arrow F2 in Fig. 4 , and can lift the article B2 upward.

[0032] 4, the first suction portion 3a and the second suction portion 3b suction onto the top surface and the left side surface of the article B2, so that the outer shape of the suction pad 1 is tilted relative to the pad attachment portion 102. However, in the suction pad 1 of the first embodiment, the shape-retaining portion 4 is in a floating state relative to the pad attachment portion 102, so that the other end 4b of the shape-retaining portion 4 is configured to be displaced in response to the elastic deformation of the suction portion 3, as indicated by the diagonally downward arrow H in Fig. 4. Furthermore, this displacement of the shape-retaining portion 4 can be performed without interfering with the elastic deformation of the suction portion 3 (i.e., the suction action of the article B2).

[0033] In this way, the suction pad 1 has a larger suction surface due to the configuration of the suction portion 3, and the contact area with the article B2 is wider, but this makes it more difficult for the suction pad 1 to return to its original shape after elastic deformation. For this reason, the shape-retaining portion 4 arranged around the suction portion 2 is configured to pull the end of the second suction portion 3b inward, and this pulling force acts as a restoring force, so that the suction portion 3 can easily return to its original shape even if it is elastically deformed.

[0034] As described above, the suction pad 1 of the first embodiment includes a bellows-shaped suction portion 2 having one end 2a connected to the pad mounting portion 102. The suction pad 1 also includes a suction portion 3 connected to the other end 2b of the suction portion 2 opposite the one end 2a and adapted to adsorb an article, the suction portion 3 including a first suction portion 3a connected to the other end 2b of the suction portion 2 and increasing in diameter as it moves away from the suction portion 2, and a second suction portion 3b folded back from the first suction portion 3a toward the pad mounting portion 102 and increasing in diameter as it moves away from the first suction portion 3a. The suction pad 1 also includes a shape retaining portion 4 connected to the second suction portion 3b side of the suction portion 3 and disposed around the suction portion 2, for retaining the shape of the second suction portion 3b when not adsorbing an article. The article holding device 100 of the first embodiment includes the suction pad 1 and a pad mounting portion 102 provided with a suction port 102a.

[0035] With the above-described configuration, in the suction pad 1 and the article holding device 100 of the present embodiment 1, the suction portion 3 can easily elastically deform in accordance with the article, and can easily adsorb the article, as shown in Figures 3 and 4. This allows the suction pad 1 and the article holding device 100 of the present embodiment 1 to improve their ability to adsorb articles.

[0036] Furthermore, in the suction pad 1 of the present embodiment 1, the shape-retaining portion 4 is in a floating state with respect to the pad attachment portion 102 when not adsorbing an article. Therefore, when adsorbing an article, the suction portion 3 can more easily elastically deform in accordance with the article, and more easily adsorb the article. This allows the suction pad 1 of the present embodiment 1 to further improve its ability to adsorb an article.

[0037] Furthermore, in the suction pad 1 of the first embodiment, the shape-retaining portion 4 is provided so as to decrease in diameter as it moves away from the second suction portion 3b, which makes it easy to miniaturize the shape-retaining portion 4 and, in turn, the configuration of the suction pad 1. Furthermore, since the shape-retaining portion 4 has a shape with a decreased diameter as described above, the rigidity of the shape-retaining portion 4 itself can also be increased.

[0038] [Embodiment 2] Embodiment 2 of the present disclosure will be described below. For ease of explanation, members having the same functions as those described in embodiment 1 will be denoted by the same reference numerals, and their description will not be repeated.

[0039] 5 is a cross-sectional end view illustrating an example of the configuration and operation of the main parts of the suction pad 1 and the pad attachment portion 102 according to the second embodiment of the present disclosure. In FIG. 5, the main difference between the first embodiment and the second embodiment is that a conductive ring 4c is provided at the other end 4b of the shape maintaining portion 4.

[0040] 5, the suction pad 1 of the second embodiment has a ring 4c as a conductive member provided on the other end 4b side of the shape-retaining part 4. As will be described later, this ring 4c is configured to be detachable from (contactable with) the pad attachment part 102 in accordance with the displacement of the position of the shape-retaining part 4 accompanying the elastic deformation of the suction part 3.

[0041] In the article holding device 100 of the second embodiment, a detection member 102c is provided on the surface of the pad mounting portion 102 on the suction pad 1 side. The detection member 102c is made of a conductive material, such as a copper wire, that is electrically conductive with the ring 4c.

[0042] Furthermore, a detector (not shown) that detects, for example, a resistance value is connected to the detection member 102c. In the article holding device 100 of the second embodiment, a control unit (not shown) is provided for the detector. The control unit is configured to be able to detect whether or not the shape maintaining unit 4 has come into contact with the detection member 102c by detecting a change in the resistance value from the detector.

[0043] Specifically, when an article is not being adsorbed, as shown in FIG. 2 , the shape maintaining portion 4 is in a floating state with respect to the pad mounting portion 102. In this case, the ring 4c is not in contact with the detection member 102c. Therefore, in the article holding device 100 of the second embodiment, the control unit detects that the detection result of the detector has not deviated from a predetermined initial value. Then, in the article holding device 100 of the second embodiment, the control unit determines, based on the detection result, that the ring 4c and the detection member 102c are not in contact with each other, and can therefore determine that the suction pad 1 is not adsorbing an article.

[0044] Furthermore, in the item holding device 100 of this embodiment 2, when the control unit determines that an item is not being adsorbed, the control unit can operate the base 101 so that the item can be adsorbed by the suction pad 1.

[0045] On the other hand, when an article is being suctioned, for example, the second suction portions 3b exert a force that pulls the upper surface of article B3 upward, as shown in Fig. 5. As a result, in the suction pad 1, the suction portions 3 suction article B3 by vacuuming the openings 3d, and are ready to suction article B3 and pull it upward. In this case, as shown in Fig. 5, the shape-retaining portion 4 is displaced toward the pad mounting portion 102 in response to the upward elastic deformation of the suction portions 3, and the ring 4c comes into contact with the detection member 102c, for example, at the locations indicated by T1 and T2 in Fig. 5.

[0046] As a result, in the article holding device 100 of the second embodiment, the control unit detects that the detection result of the detector has deviated from a predetermined initial value. In other words, the control unit detects that the resistance value detected by the detector has changed from its initial value due to the ring 4c coming into contact with the detection member 102c. In the article holding device 100 of the second embodiment, the control unit determines, based on the detection result, that the ring 4c and the detection member 102c are in contact with each other, and can therefore determine that the suction pad 1 is holding an article.

[0047] Furthermore, in the article holding device 100 of the second embodiment, the control unit stops the operation of the suction pad 1 to approach the article, for example, the lifting operation, by stopping the operation of the base 101. Furthermore, since the control unit determines that the suction pad 1 is adsorbing the article, it starts vacuuming from the suction port 102a, allowing the suction pad 1 to start adsorbing the article.

[0048] With the above configuration, the second embodiment provides the same effects as the first embodiment.

[0049] Furthermore, in the suction pad 1 of the second embodiment, a detachable ring 4c is provided on the pad attachment portion 102 of the shape maintaining portion 4. This makes it possible to detect whether or not the suction portion 3 has come into contact with an article. This allows for accurate determination of whether or not the suction portion 3 has adsorbed an article.

[0050] Furthermore, in the article holding device 100 of the second embodiment, the pad attachment portion 102 is provided with a detection member 102c that detects contact of the shape maintaining portion 4. This makes it possible to detect displacement of the shape maintaining portion 4 so as to come into contact, and to detect whether the suction portion 3 has come into contact with an article. This allows for accurate determination of whether the suction portion 3 has adsorbed an article.

[0051] As described above, in the second embodiment, the shape maintaining portion 4 changes position in response to the elastic deformation of the suction portion 3, and this is utilized to cause the shape maintaining portion 4 to function as an indirect contact detection means for detecting contact of the suction pad 1 with the article. As a result, in the second embodiment, it is possible to easily configure a low-cost article holding device 100, and in turn, a low-cost picking device, compared to a case where an imaging means such as a camera is installed to detect contact of the suction pad 1 with the article.

[0052] Furthermore, in the article holding device 100 of the second embodiment, after it is determined that the suction pad 1 has come into contact with an article, the operation of the pad attachment portion 102 (i.e., the picking head) is stopped. This makes it possible to prevent the suction pad 1 from coming into excessive contact with the article, and also to prevent damage to the article due to excessive contact.

[0053] However, depending on the shape or material of the article, the suction pad 1 may be moved a predetermined distance (for example, several mm) toward the article after it is determined that the suction pad 1 has come into contact with the article. In this case, the suction pad 1 can improve its ability to adsorb articles, making it easier to transfer relatively heavy articles.

[0054] In addition to the above description, the presence or absence of contact between the detection member 102c and the ring 4c may be detected using, for example, a change in the value of the power (voltage value and / or current value) supplied to the detection member 102c or a change in the dielectric constant of the detection member 102c as a change in an electrical characteristic other than a change in resistance value.

[0055] In addition to the above description, a detection member that detects the proximity of the shape-retaining part 4 by using an electromagnetic method may be provided on the pad attachment part 102. Also, a sensor element such as a proximity sensor or a pressure sensor may be installed on the pad attachment part 102 as a detection member.

[0056] Modification of Embodiment 2 A modification of Embodiment 2 of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in Embodiment 2, and the description thereof will not be repeated.

[0057] Fig. 6 is a cross-sectional end view illustrating an example of the configuration and operation of a main part of a modified example of the pad attachment portion 102 shown in Fig. 5. In Fig. 6, the main difference between the modified example of the second embodiment and the second embodiment is that a side detection member 102d is provided to detect lateral displacement of the suction pad 1.

[0058] As shown in Fig. 6, in the article holding device 100 of this modified example, a cylindrical side detection member 102d is provided on the pad mounting portion 102. Like the detection member 102c, this side detection member 102d is made of a conductive material, such as a copper wire, that is electrically conductive with the ring 4c. Like the mounting member 102b, the side detection member 102d is provided so as to protrude on the side opposite the base and is configured to contact the outer circumferential surface of the suction portion 2. As shown in Fig. 6, the article holding device 100 of this modified example is capable of detecting, for example, contact of the suction pad 1 with the side wall of a container that stores articles.

[0059] Specifically, when the suction pad 1 comes into contact with the side wall of the container, a force acts on the suction pad 1 from the side wall, as shown by arrow F3 in Fig. 6, causing the suction pad 1 to elastically deform. In other words, the suction pad 1 elastically deforms in a lateral direction perpendicular to the vertical direction, which is the attachment direction to the pad attachment portion 102, i.e., in the left-right direction on the page of the drawing. As a result, in the suction pad 1, the shape maintaining portion 4 is displaced as shown by arrow F4 in Fig. 6 in conjunction with the elastic deformation in the left-right direction, and the ring 4c comes into contact with the side detection member 102d. As a result, in the article holding device 100 of this modified example, the control unit can determine that the suction pad 1 has come into contact with the side wall or the like before the suction portion 3 adsorbs the article.

[0060] Furthermore, in the article holding device 100 of this modified example, the control unit determines that an abnormal operation has occurred when it determines that the suction pad 1 has come into contact with the side wall, etc. Then, in the article holding device 100 of this modified example, the control unit can easily notify an occurrence of the abnormal operation on a display unit (not shown) or the like, stop the operation of the article holding device 100 (picking device), or continue the suction operation of the article holding device 100 (picking device) without stopping the operation of the article holding device 100 (picking device).

[0061] [Modifications of Suction Pad] Modifications of the suction pad 1 of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the first embodiment, and the description thereof will not be repeated.

[0062] Fig. 7 is a cross-sectional end view illustrating an example of the main configuration of the suction pads 11 and 21 according to Modifications 1 and 2. In 101 of Fig. 7, the main difference between Modification 1 and Embodiment 1 is that the protrusion dimension of the shape maintaining portion 14 toward the pad attachment portion 102 is reduced. In 102 of Fig. 7, the main difference between Modification 2 and Embodiment 1 is that only the end portion 24a of the second suction portion 3b is provided in the shape maintaining portion 24.

[0063] 7 , in the suction pad 11 of the first modified example, one end 14a of the ring-shaped shape-retaining portion 14 is connected to the second suction portion 3b side of the suction portion 3. The shape-retaining portion 14 is also configured so that its diameter decreases with increasing distance from the second suction portion 3b, and the other end 14b is formed in a ring shape configured to have a predetermined thickness in order to impart higher rigidity to the shape-retaining portion 14 than the suction portion 3.

[0064] Furthermore, in the suction pad 11 of Modification 1, unlike that of Embodiment 1, the dimension of the shape-retaining portion 14 in the vertical direction is approximately half the dimension of the suction portion 2 in the vertical direction. In this way, in the suction pad 11 of Modification 1, the dimension of the shape-retaining portion 14 is set short, so that it is possible to prevent the elastic deformation of the suction portion 3 from being hindered due to contact with the pad attachment portion 102.

[0065] 7 , in the suction pad 21 of the second modification, the shape-retaining portion 24 does not decrease in diameter as it moves away from the second suction portion 3b, and the end portion 24a is connected to the second suction portion 3b side of the suction portion 3. The end portion 24a is formed in a ring shape configured to have a predetermined thickness in order to impart higher rigidity to the shape-retaining portion 24 than the suction portion 3.

[0066] Furthermore, in the suction pad 21 of the second modification, the shape maintaining portion 24 is composed only of the end portion 24a that connects the ends of the second suction portions 3b, so that the configuration of the suction pad 21 can be simplified.

[0067] [Summary] The suction pad of a first aspect of the present disclosure is an suction pad that is attached to a pad attachment portion provided with a suction port of an article holding device that holds an article, and includes: a bellows-shaped suction portion having one end connected to the pad attachment portion; an suction portion that is connected to the other end of the suction portion opposite the one end and that adsorbs to an article, the suction portion having a first suction portion that is connected to the other end of the suction portion and that expands in diameter as it moves away from the suction portion, and a second suction portion that is folded back from the first suction portion toward the pad attachment portion and that expands in diameter as it moves away from the first suction portion; and a shape retention portion that is connected to the second suction portion side of the suction portion, is arranged around the suction portion, and maintains the shape of the second suction portion when the article is not being adsorbed.

[0068] According to the above configuration, the suction portion having the first suction portion and the second suction portion is provided at the suction port of the article holding device. Furthermore, since the shape-retaining portion maintains the shape of the second suction portion when not holding an article, the suction portion can easily elastically deform in accordance with the article and easily hold the article. This improves the suction ability to hold the article.

[0069] A second aspect of the present disclosure is the suction pad of the first aspect, wherein the shape-retaining portion may be disposed spaced apart from the pad attachment portion when the article is not being suctioned.

[0070] According to the above configuration, the shape-retaining portion is in a floating state relative to the pad attachment portion when the article is not being adsorbed. Therefore, when the article is adsorbed, the adsorption portion can more easily elastically deform in accordance with the article, and can more easily adsorb the article. This further improves the adsorption ability to the article.

[0071] A third aspect of the present disclosure is the suction pad of the first or second aspect, wherein the shape-retaining portion may be configured to decrease in diameter as it becomes farther away from the second suction portion.

[0072] According to the above configuration, it is possible to easily reduce the size of the shape-retaining portion, and therefore the size of the suction pad.

[0073] A fourth aspect of the present disclosure is the suction pad according to any one of the first to third aspects, wherein the shape-retaining portion may have higher rigidity than the suction portion.

[0074] According to the above configuration, the rigidity of the shape-retaining portion is higher than the rigidity of the suction portion, so that the shape-retaining portion can reliably hold the suction portion when the suction portion is not suctioning an article.

[0075] A fifth aspect of the present disclosure is the suction pad of any one of the first to fourth aspects, wherein the shape-retaining portion may be provided with a detachable conductive member at the pad attachment portion.

[0076] According to the above configuration, by using the conductive member, it becomes possible to detect whether or not the suction part has come into contact with an article, thereby enabling accurate determination of whether or not the suction part has attracted the article.

[0077] An article holding device of a sixth aspect of the present disclosure is an article holding device having a pad mounting portion with a suction port, and is equipped with a suction pad comprising: a bellows-shaped suction portion having one end connected to the pad mounting portion; an suction portion connected to the other end of the suction portion opposite the one end and adapted to adsorb to an article, the suction portion having a first suction portion connected to the other end of the suction portion and increasing in diameter as it moves away from the suction portion, and a second suction portion folded back from the first suction portion toward the pad mounting portion and increasing in diameter as it moves away from the first suction portion; and a shape retaining portion connected to the second suction portion side of the suction portion, arranged around the suction portion, and adapted to retain the shape of the second suction portion when the article is not being adsorbed.

[0078] According to the above configuration, an article holding device can be configured that can improve the adsorptive properties for articles.

[0079] A seventh aspect of the present disclosure is the article holding device of the sixth aspect, wherein the pad attachment portion may be provided with a detection member that detects proximity or contact of the shape maintaining portion.

[0080] According to the above configuration, the detection member can detect that the shape-retaining part has been displaced so as to approach or come into contact with the article, and can detect whether the suction part has come into contact with the article, thereby enabling accurate determination of whether the suction part has adsorbed the article.

[0081] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Configurations obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present disclosure.

[0082] REFERENCE SIGNS LIST 1, 11, 21 suction pad 2 suction portion 2a one end 2b other end 3 suction portion 3a first suction portion 3b second suction portion 4 shape-retaining portion 4c ring (conductive member) 100 article holding device 102 pad attachment portion 102a suction port 102c detection member

Claims

1. A suction pad that is attached to a pad mounting section provided with a suction port of an article holding device that holds an article, comprising: a bellows-shaped suction section having one end connected to the pad mounting section; an suction section connected to the other end of the suction section opposite the one end and adsorbing to an article, the suction section having a first suction section connected to the other end of the suction section and expanding in diameter as it moves away from the suction section, and a second suction section that is folded back from the first suction section towards the pad mounting section and expands in diameter as it moves away from the first suction section; and a shape retention section connected to the second suction section side of the suction section and disposed around the suction section, for retaining the shape of the second suction section when the article is not being adsorbed.

2. The suction pad according to claim 1, wherein the shape-retaining portion is positioned away from the pad attachment portion when the article is not being suctioned.

3. The suction pad according to claim 1, wherein the shape-retaining portion is configured to decrease in diameter as it moves away from the second suction portion.

4. The suction pad according to claim 1, wherein the shape-retaining portion has higher rigidity than the suction portion.

5. The suction pad according to any one of claims 1 to 4, wherein the shape-retaining portion is provided with a detachable conductive member at the pad attachment portion.

6. An article holding device having a pad mounting portion with a suction port, comprising an occlusion pad comprising: a bellows-shaped suction portion having one end connected to the pad mounting portion; an occlusion portion connected to the other end of the suction portion opposite the one end and suctioning an article, the occlusion portion having a first suction portion connected to the other end of the suction portion and expanding in diameter as it moves away from the suction portion, and a second suction portion folded back from the first suction portion towards the pad mounting portion and expanding in diameter as it moves away from the first suction portion; and a shape retention portion connected to the second suction portion side of the suction portion, disposed around the suction portion, and retaining the shape of the second suction portion when the article is not being suctioned.

7. The article holding device according to claim 6, wherein a detection member is provided at said pad attachment portion for detecting the proximity or contact of said shape maintaining portion.

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