JP2019104067A - Gripping member, gripping tool, and gripping device - Google Patents

Abstract

To provide a gripping member, a gripping tool, and a gripping device which are excellent in gripping stability.SOLUTION: A bag 26, which is a bag-like gripping member, comprises a bag body 31 which is a deformable, bag-like member body, and two projections 32. The bag 26 presses an object to be gripped in a state of storing grains 27 therein, and grips the object to be gripped by depressurizing an inside thereof. An opening 31c for putting the grains therethrough is formed on the bag body 31. The two projections 32 are provided on an outer surface 31s of the bag body 31 with an interval. A region of the outer surface 31s between the two projections 32 is a curved surface projecting outward.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to a gripping member, a gripping tool, and a gripping device.

  The particles behave as a fluid when the density is below a certain threshold, and behave as a solid when the density is above the threshold. A state change corresponding to the density of such particles is called a jamming transition, and a gripping device utilizing this jamming transition is known.

  The gripping device presses the object to be grasped with a deformable bag-like body (hereinafter referred to as a bag) that accommodates the particles in a flowing state, and the pressing causes the bag to be shaped along the outline of the object to be grasped In the state where it is deformed and pressed, pressure is reduced by sucking the internal gas from the suction port of the bag. The reduced pressure lowers the density of the particles inside the bag, and the particles are solidified to hold the object to be gripped.

  As such a gripping device, particles made of foamed polyethylene having a particle diameter of 0.1 mm or more and 4.0 mm or less are accommodated in the bag, and resistance in a predetermined region extending from the suction port of the bag to the side gripping the object A gripping device which is larger than the other parts has been proposed (see, for example, Patent Document 1). In the bag, the thickness of the predetermined area is larger than that of the other parts in order to make the resistance in the predetermined area larger than that of the other parts.

  There has also been proposed a gripping device provided with a bag in which the periphery of the gripping region is projected outside the gripping region (see, for example, Patent Document 2). In this bag, the granules are also contained in the projecting portion as described above, and the gripping area is flat and disk-like. The gripping device of Patent Document 2 changes the posture of the protruding portion by solidifying the particles stored in the protruding portion of the bag.

JP, 2013-240853, A JP 2017-185553 A

  However, the gripping device described in Patent Document 1 has a weak gripping force (gripping force), and therefore, the gripping object can not be gripped, or the gripped gripping object may fall off. Moreover, the bag of patent document 2 may not be able to be gripped in some cases, since the granular material may not fully enter the protruding part. In addition, when the grip is released, the particles of the protruding portion may not be solidified while being solidified, and as a result, the next gripping may not be possible, for example, the protruding portion may not return to the original posture. For this reason, the grip stability is desired that the grip is secure and that the gripped object is not dropped.

  Then, an object of this invention is to provide the holding member excellent in holding | grip stability, a holding | grip tool, and a holding | grip apparatus.

  In order to solve the above-mentioned subject, the bag-like grasping member of the present invention is provided with a deformable material main body and a plurality of projections, and presses the grasped object in a state that the granular material is accommodated, The object to be grasped is grasped by being sucked. The member main body is in the form of a bag in which an opening for containing the particles is formed. The plurality of protrusions are provided at intervals on the outer surface of the member body. The region between the plurality of projections on the outer surface of the member body is a curved surface that is convex outward.

  It is preferable that the plurality of projections form a pressing area for pressing the object to be grasped among the outer surfaces of the member main bodies. It is preferable that the projection be provided in a state in which the tip is directed to the pressing area side. It is preferable that the surface of the projection on the pressing area side be formed flat.

  The protrusions are preferably elastically deformed. The plurality of projections are respectively provided on two circles which are concentric circles, and it is preferable that the number of projections in one of the larger of the two circles is larger than the number of projections in the other small circle.

  A gripping tool according to the present invention includes the above-described gripping member, and a granular material accommodated in the above-mentioned member main body of the gripping member.

  The holding tool preferably includes a support member for supporting the holding article, and the support member is provided to close the opening of the holding member.

  A gripping device according to the present invention includes the gripping tool and a suction unit. The suction unit sucks the gas inside the gripping member.

  According to the present invention, gripping with excellent stability can be performed.

It is explanatory drawing of the conveying machine which implemented this invention. It is a side schematic diagram of a conveying machine. It is the schematic of a holding | grip apparatus, (A) is a partial cross section front view, (B) is a bottom view. It is an explanatory view of thickness distribution of a bag body. It is an explanatory view of thickness distribution of a bag body. It is explanatory drawing of protrusion. It is explanatory drawing of protrusion. It is the schematic of the gripper which is another embodiment, (A) is sectional drawing, (B) is a bottom view. It is explanatory drawing of the protrusion which is another embodiment, (A) is a front view, (B) is a bottom view. It is explanatory drawing of the protrusion which is another embodiment, (A) is a front view, (B) is a bottom view. It is explanatory drawing of the protrusion which is another embodiment, (A) is a front view, (B) is a bottom view. It is explanatory drawing of the protrusion which is another embodiment, (A) is a front view, (B) is a bottom view. It is explanatory drawing of the protrusion which is another embodiment, (A) is a front view, (B) is a bottom view. It is explanatory drawing of protrusion which is another embodiment. It is explanatory drawing of protrusion which is another embodiment. FIG. 7 is a bottom view of another embodiment of a bag. FIG. 7 is a bottom view of another embodiment of a bag. It is explanatory drawing of the bag which is another embodiment, (A) is a partial cross section front view, (B) is a bottom view. FIG. 7 is a bottom view of another embodiment of a bag. FIG. 7 is a bottom view of another embodiment of a bag. It is a cross-sectional schematic diagram of the bag which is another embodiment.

  The transport machine 10 of FIG. 1 in which the present invention is implemented is for transporting the gripping object 12 supplied to the supply table 11 to the receiving table 13. The supply stand 11 and the receiving stand 13 are arranged around the carrier 10 when viewed from above. A plurality of objects to be grasped 12 are placed on the supply stand 11, and the number placed is illustrated as three in FIG.

  The gripping object 12 in this example has a shape in which one end of a cylinder is rounded in a spherical shape, but the shape of the gripping object is not limited to this example. Although the three grip objects 12 have the same size as each other, the postures in which they are placed may be different as shown in FIG. Also, the gripping objects may be of different shapes and / or sizes.

  The transporter 10 grips the object to be grasped 12 by the gripper 18 of the grasping device 17 provided at the tip of the arm portion 16 and moves the object to be grasped 12 by turning and bending the arm portion 16. That is, the plurality of gripping objects 12 on the supply stand 11 are transported to the receiving stand 13 one by one. The receiving table 13 is provided with a conveyor 13a, and the objects to be grasped 12 transported from the supply table 11 are sequentially sent to the next process by the movement of the conveyor 13a.

  As shown in FIG. 2, the transport device 10 is configured to include an arm portion 16, a support 21 for supporting the arm portion 16, and a gripping device 17 attached to the tip of the arm portion 16. The gripping device 17 is a device for gripping the object to be grasped 12 utilizing the jamming phenomenon of the particles 27 (see FIG. 3A). The gripping device 17 has a gripper 18 as a gripping tool and a vacuum pump 22 as a suction unit. The gripping device 17 preferably further comprises a gripper holder 23, which is the same in this example. The gripper 18 includes a bag-like bag 26 and granules 27 (see FIG. 3A) accommodated inside the bag 26. In this example, the base 28 is also a plate-like support member for supporting the bag 26. Have.

  The bag 26 is a gripping member that grips the gripping object 12. The bag 26 has a bag main body 31 which is a bag-like member main body, and a plurality of protrusions 32 provided on the outer surface 31s (see FIG. 3A) of the bag main body 31. Is one. The bag body 31 is deformable, and is elastically deformed by the pressing of the object to be grasped 12 (hereinafter referred to simply as pressing) and the suction of the gas inside (hereinafter referred to as the inner suction). The shape of the bag main body 31 along the outer shape of the gripping object 12 by pressing the gripping object 12 with the bag main body 31 with the bag 26 containing the particles 27 (see FIG. 3A) in a flowable manner. And the tips of the protrusions 32 tilt in the directions of each other. In the pressed state, the internal gas is sucked by the vacuum pump 22 so that the internal pressure is reduced, and the particles 27 solidify by jamming transition. Thus, the gripping device 17 grips the gripping object 12. Further, the pressure inside the bag body 31 returns to the original atmospheric pressure by releasing the suction, and the particles 27 are fluidized. Thus, the gripping device 17 releases the gripping of the gripping object 12.

  The gripping device 17 can take various postures by the arm portion 16, but in the present embodiment, the gripping device 17 will be described as the posture in which the plate-like base 28 is horizontal with the gripper 18 being on the lower side. The details of the gripper 18 including the bag 26 and the like will be described later using another drawing.

  The gripper holding portion 23 holds the gripper 18 at the tip of the arm portion 16 and displaces the bag 26 when holding and releasing the holding object 12. The gripper holding portion 23 has a main body portion 23a, a shaft 23b, and a connecting portion 23c. The arm portion 16 has arms 16a to 16d, and the arm 16a is at the tip. The main body 23a is fixed to the tip of the arm 16a, and the shaft 23b is slidably attached to the main body 23a in the vertical direction. The lower end of the shaft 23b is fixed to the base 28 by the connecting portion 23c, whereby the bag 26 of the gripper 18 is smoothly displaced in the vertical direction. By this displacement, the distance between the bag 26 and the supply stand 11 and / or the object to be held 12 is increased or decreased. For example, in the case of pressing, the bag 26 is lowered to reduce the distance between the supply stand 11 and the grasped object 12. Further, for example, when the object to be grasped 12 is lifted from the supply stand 11 after internal suction, the bag 26 is raised to increase the distance to the supply stand 11.

  The bag body 31 is connected to a vacuum pump 22 via a suction control unit 33, and the vacuum pump 22 is a suction unit for sucking the gas inside the bag body 31. The suction control unit 33 is for controlling the jamming transition of the particles 27. That is, the suction control unit 33 regulates the flow of the particles 27 by turning on the suction by the vacuum pump 22 (makes the non-flowing state), and turns the particles 27 off by releasing the suction (releasing). Fluidize. The gripping device 17 grips and releases the gripping object 12 by the displacement of the bag 26 in the vertical direction and the control of the internal suction as described above.

  The arm unit 16 has arms 16a to 16d and a pivoting mechanism 16e, and the arms 16a to 16d are each connected so as to be bendable around a horizontal axis. One end of an arm 16d is bendably connected to the turning mechanism 16e, and the turning mechanism 16e is rotatably provided on the support base 21 around a vertical axis.

  The arm unit 16 is driven by an arm drive unit 36. The arm drive unit 36 is configured of a motor or the like for driving the arm unit 16. The arms 16a to 16d are bent by the arm driving unit 36, and the turning mechanism 16e performs turning. Thereby, the gripped object 12 can be moved horizontally (in the vertical direction) in any direction and in the vertical direction. The arm drive unit 36 is controlled by an arm control unit 37.

  The gripper position detector 38 is incorporated in the gripper holder 23. The gripper position detector 38 detects the position of the bag 26 in the vertical and horizontal directions, ie, the position in three-dimensional space (hereinafter referred to as three-dimensional coordinates) when gripping the gripping target 12 and releasing the gripping. The detection result is output to the arm control unit 37.

  Each first three-dimensional coordinate of the bag 26 and a second three-dimensional coordinate for releasing the grip of the gripped bag 26 are previously recorded in the arm control unit 37 when the plurality of gripped objects 12 are gripped respectively. There is. The arm control unit 37 calculates the moving direction and moving amount of the bag 26 to be moved based on the detection result from the gripper position detector 38 and the first three-dimensional coordinates or the second three-dimensional coordinates, and the calculation result The arm drive unit 36 is controlled based on Thus, under the control of the arm control unit 37, the arm drive unit 36 moves the gripping device 17 between the first three-dimensional coordinates on the supply table 11 and the second three-dimensional coordinates on the receiving table 13. Let

  As shown to FIG. 3A, the bag main body 31 which accommodates the several particle | grains 27 integrally forms the cylinder part 31a which is a cylindrical shape of a cross-sectional perfect circular shape, and spherical crown, specifically hemispherical bottom part 31b. It has a bag-like shape. The opening 31c is an inlet / outlet for the granules 27. When the beginning of use and the granules 27 are to be increased, the granules 27 are put in from the opening 31c and taken out when the amount is reduced. The bag body may be configured of only the bottom 31b, in which case the top of the bottom 31b is the opening 31c.

  The bottom 31 b is a spherical crown of a true sphere which is a true circular cross-section, but may be a crown of an ellipsoid (a spheroid) whose cross section is an ellipse. Further, the bottom is not limited to a crown, and for example, the cross-sectional shape vertically intersecting the horizontal direction in FIG. 3A may be a shape convex outward, such as a hyperbolic shape.

  The two protrusions 32 are provided to project from the outer surface 31s of the bag body 31 with a gap, thereby, as shown in FIG. 3A (B), among the outer surfaces 31s of the bag body 31. Form a pressing area PA. The pressing area PA is an area for pressing the object to be grasped 12.

  The projections 32 form a pressing area PA in pairs, that is, in pairs. However, the number of the projections 32 forming one set is not limited to two, and may be at least two. Thus, a plurality of projections 32 form a pressed area PA. The pressing area PA is a conceptual area virtually defined by a pair of projections 32. Therefore, the double broken line indicating the pressing area PA in FIG. 3A does not indicate a clear outline, and is drawn as an ellipse for the convenience of description. However, within the range of such an ellipse, reliable gripping of the gripping object 12 is possible.

  Since the projections 32 are provided on the bottom 31b of the bag body 31 which is convex outward, the pressing area PA of the outer surface 31s is convexly curved outward.

  FIG. 3A shows a state before use of the bag 26 (hereinafter referred to as an initial state), and the bag body 31 is elastically deformed by pressing and internal suction as described above. Specifically, during pressing of the object to be grasped 12 and when the gas inside is sucked, the gas is dented inside, and the case where the pressing is released and the case where the internal suction is released are shown in FIG. 3A. Return to the state of During pressing, the pressing area PA is depressed in a direction opposite to the pressing direction for pressing the object to be grasped 12 (hereinafter referred to as the reverse pressing direction) so that the projection 32 is biased toward the pressing area PA. It inclines in an inclined posture compared to. Further, when the pressing is released, the deformation, which is the elastically biased dent of the pressing area PA, is released, and the posture of the projection 32 returns to the initial state.

  The material constituting the bag body 31 is not particularly limited as long as the material elastically deforms by pressing and internal suction, and examples thereof include nitrile rubber, natural rubber, styrene butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile nitrile butadiene Rubber, butyl rubber, ethyl propylene rubber, ethyl propylene diene rubber, urethane rubber, silicone rubber, fluoro rubber, vinyl rubber, etc. may be mentioned, and any material that can make the inside of the bag body 31 airtight can be foam rubber. Absent. In this example, silicone rubber is used. More preferably, the material of the bag body 31 is softer than the object 12 to be grasped.

  The bag body 31 may have a multilayer structure made of the same material or different materials. By using a multilayer structure of different materials, it is possible to change the properties of the bag body 31 such as flexibility and mechanical properties. For example, in order to enhance the durability of the bag body 31, the bag body 31 is formed of the various rubbers as described above in the thickness direction, and the outside constituting the outer surface 31s is formed of, for example, a metal mesh Aspects such as may be used. By covering with a metal mesh or the like, damage such as breakage of the bag body 31 is more reliably prevented. Also, the outer surface 31s may be made of a material that enhances the frictional force with the object to be grasped 12 and / or the stickiness. This makes the grip more stable.

  Here, the thickness of the bag body is T31. The thickness T31 may be appropriately set in consideration of strength and ease of deformation, and is not particularly limited. However, in the thickness T31, it is preferable that the pressing area PA be smaller than the cylindrical portion 31a, so that the posture of the projection 32 is more likely to change with certainty at the time of pressing. In this respect, the range in which the thickness T31 is smaller than that of the cylindrical portion 31a is preferably at least the pressing area PA, and when the bag body 31 is viewed from the pressing direction, as shown in FIG. 3A (B) It may be the inner area of the smallest circle (two-dot broken line RLa) that includes. The range in which the thickness T31 is smaller than that of the cylindrical portion 31a is more preferably a region including a circle RLb passing through the center of gravity PG (see FIG. 5) of the bottom surface of each protrusion 32. In a region including a circle RLc inscribed by each protrusion 32 Being particularly preferred. The thickness T31 in the present example is smaller than the cylindrical portion 31a in a region including a circle RLc in which each protrusion is inscribed. The thickness T31 is preferably gradually decreased from the cylindrical portion 31a toward the pressing area PA from the viewpoint of the durability of the bag main body 31, and it is preferable that the thickness T31 be gradually decreased rather than stepwise decreased. It is more preferable, and in this example it is so. Further, in the present example, the thickness T31 is gradually decreased, more specifically, continuously decreased gradually toward the center of the circle RLc, and the thickness T31 at the center of the pressing area PA is formed to be the smallest. In the present example in which the bag body 31 is formed of silicone rubber (within the range of hardness A40 or more and A50 or less determined by durometer type A according to JIS K 6249), the thickness T31 of the cylindrical portion 31a is 5 mm, and the pressing area PA The thickness T31 at the center of is 2 mm.

  From the viewpoint of making it easier to change the attitude of the projection 32 more reliably when pressed, there is also a method of making the thickness T31 of the bag body 31 between the projection 32 and the projection 32 smaller than the thickness T31 of the other region. For example, as in the bag body 39 of FIG. 3B, an example in which a region extending linearly between one protrusion 32 and the other protrusion 32 is a thin film region TA having a thickness T31 smaller than the other region is given. Be The same may be applied to the case where the number of projections 32 forming one set is more than two as described later. For example, as in the case of the bag body 40 shown in FIG. 3C, when the number of the protrusions 32 forming a pair is three, the linearly extending region between the protrusions 32 is used as the radial thin film region TA. It should be formed.

  The projection 32 may be any of a deformable projection formed of an elastically deformable material and, for example, a projection (hard projection) so rigid that it does not deform upon contact and pressure with the supply table 11 (see FIG. 2). In the example, a deformable projection 32 is used. Examples of the material that elastically deforms when forming the projections 32 include nitrile rubber, natural rubber, styrene butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, butyl rubber, ethyl propylene rubber, and ethyl Propylene diene rubber, urethane rubber, silicone rubber, fluorine rubber, vinyl rubber, foamed rubber, etc. may be mentioned, and in this example, the same silicone rubber as the bag body 31 is used.

  As the particles 27 shown in FIG. 3A (A), known particles used in a gripping device using the jamming phenomenon can be used. For example, the particle diameter is not particularly limited, but is preferably in the range of 0.3 mm or more and 3 mm or less, and is 0.5 mm in this example. Also, for example, coffee powder, rice grains, resin (polymer compound) may be mentioned as the raw material. In FIG. 3A, the particles 27 are drawn in a circular shape for the sake of convenience, but may be a circular shape or another shape.

  The amount of the particles 27 is preferably such that the particles 27 can be present on the inner side of the portion of the bag body 31 in which the projections 32 are formed, in a state of being internally sucked. Here, the volume (internal volume) of the bag body 31 in the initial state is V31, and the volume occupied by the particles 27 (hereinafter referred to as an occupied volume) is V27. The occupied volume V27 in the initial state is preferably in the range of 0.2 × V31 or more and 0.9 × V31 or less, and more preferably in the range of 0.4 × V31 or more and 0.7 × V31 or less In this example, it is 0.5 * V31.

  As shown in FIG. 3A (A), the base 28 is provided in a state of closing the opening 31c, and in this example, in order to improve the workability in the case of increasing or decreasing the particles 27 as described above, it is detachable. It is The base 28 has a disk shape, and the central portion 28 a protrudes toward the bag body 31 and is formed thicker than the outer peripheral portion 28 b. However, the shape of the base 28 is not limited to this example.

  The base 28 has a through hole 28 c connected to the vacuum pump 22. Although the position of the through hole 28 c in the base 28 is not particularly limited, it is located at the center of the base 28 in this example. This is a position where the distances to the respective projections 32 are equal to each other, whereby the negative pressure (suction pressure) generated by the vacuum pump 22 is more evenly applied to the entire area of the pressing area PA in the internally suctioned state. It is because

  A filter 41 is provided in the through hole 28c. The filter 41 is hatched for convenience in FIG. 3A, but is formed in a net shape. The filter 41 is a solid-gas separation filter that separates the particles 27 from the gas. As a result, when the vacuum pump 22 sucks, the particles 27 are prevented from coming out of the bag body 31, and only gas is sucked from the inside of the bag body 31. Further, when the suction of the vacuum pump 22 is released, the gas enters the bag body 31.

  The projections 32 are conical in cross section, but may be conical in cross section. Moreover, it may be a truncated cone shape. In addition, although the projection 32 may have a sharp tip 32t, in the present example, the projection 32 has a rounded shape as shown in FIG. 4, thereby securing a larger contact area with the object 12 to be grasped It makes it possible to make the grip more stable. Here, as shown in FIG. 4, the connection point on the side of the pressing area PA where the protrusion 32 is connected to the bag body 31 is denoted by the code PB1, and the connection point farthest from the pressing area PA is denoted by the code PB2. It is preferable that the tips 32t of the pair of two projections 32 are separated from each other by a distance between the connection point PB1 at one of the projections 32 and the connection point PB1 at the other of the projections 32. I have to.

  The projection 32 is preferably provided in a state in which the tip 32t is directed to the pressing area PA side, and this is also the case in this example. A projection point obtained by projecting the connection point PB1 onto a plane (hereinafter referred to as a projection plane) PL1 which intersects perpendicularly with the pressing direction and passes through the tip 32t is PP1 and a projection point obtained by projecting the connection point PB2 is PP2. A middle point between the point PP1 and the projection point PP2 (hereinafter referred to as a projection middle point) is referred to as PM. The state in which the tip 32t is directed to the pressing area PA side means a state in which the tip 32t is located on the pressing area PA side with respect to the projection midpoint PM or on the projection midpoint PM. In the case where the protrusion has a truncated cone shape, the tip of a virtual cone obtained by extending the generatrix may be regarded as the tip of the protrusion, and the tip may be directed to the pressing area PA side.

  Since the projections 32 are formed on the curved surface portion of the outer surface 31s, the bottom surface of the conical projection 32 coincides with the outer surface 31s and is strictly a curved surface. However, as shown in FIG. 5, since the plane PL2 including an ellipse which is a conical curve passing through the connection point PB1 and the connection point PB2 is very close to the above-mentioned exact bottom surface of the projection 32, this plane PL2 is used in this embodiment. Is regarded as the bottom of the projection 32. Therefore, in the present embodiment, the center of gravity PG of the bottom surface of the protrusion 32 is not the center of gravity at the above-described exact bottom surface, but the center of gravity of the elliptical plane PL2.

  The diameter d of the projection 32 is not particularly limited, but in order to further improve the gripping stability, it is preferably at least 2 mm when formed of silicone rubber as in this example, and in this example, for example, 5 mm There is. As shown in FIG. 5, the diameter of the bottom of a cone having a bottom passing through the center of gravity PG is defined as the diameter d of the projection 32.

  Here, the diameter of a circle RLb (see FIG. 3A (B)) passing through the center of gravity PG of the bottom of the pair of two protrusions 32 is D1 (see FIG. 3A (B)) mm. The height h of the projection 32 is not particularly limited, but is preferably in the range of (the thickness of the portion where the projection of the bag main body is provided) to D1 / 2 mm or less, and is 7 mm in this example. Holding by the height h of the protrusion 32 (the thickness of the portion where the protrusion of the bag body is provided) or more is larger than when it is less than the thickness of the portion where the protrusion of the bag body is provided) It is more stable. Since the probability that the protrusions 32 abut each other at the time of pressing is lower than when the height h of the protrusions 32 is D1 / 2 mm or less, the gripping action by the protrusions 32 is more reliable. As shown in FIG. 5, the height h of the projection 32 is the distance from the center of gravity PG to the tip 32t. When the protrusion is frusto-conical, the distance from the center of gravity PG of the bottom surface to the center of gravity of the tip surface may be the height h of the protrusion.

  The operation of the above configuration will be described. Under the control of the arm control unit 37, the arm drive unit 36 drives the arm unit 16 to position the bag 26 of the gripping device 17 at the first three-dimensional coordinates on the supply stand 11. The gripping device 17 guided to the first three-dimensional coordinates lowers the gripper 18 by sliding down the shaft 23 b and presses the gripping object 12 by the bag body 31 of the bag 26. By this pressing, the pressing area PA of the bag main body 31 is deformed to a shape along the outer shape of the object to be gripped 12, and the projection 32 is inclined toward the pressing area PA compared to the initial state before pressing. For example, the tip 32 t abuts on the grasped object 12.

  In a state where the object to be grasped 12 is pressed, internal suction is performed by the vacuum pump 22 to restrict and solidify the flow of the particles 27. Thereby, the object to be grasped 12 is grasped in the pressing area PA and also grasped by the two protrusions 32.

  The particles 27 perform the gripping action of gripping the object to be grasped 12 via the bag body 31 in the pressing area PA. The particles 27 further support the projections 32 in a posture for holding the object to be grasped 12, and the projections 32 have the object to be grasped by the particles 27 in a solidified state. The durability of the gripping force and the gripping force (hereinafter referred to as gripping force) is enhanced.

  Since the pressing area PA of the outer surface 31s is a convex curved surface outward, a larger area (hereinafter referred to as a contact area) to be bonded to the object to be grasped 12 is secured larger. Therefore, the gripping stability is further enhanced. In addition, since a larger contact area with the object to be grasped 12 is secured, the fall-down of the projection 32 to the pressing area PA side with pressing can be ensured, and thus the gripping stability is further enhanced.

  Since the projections 32 are provided on the outer surface 31s of the deformable bag main body 31, the elastic deformation of the bag main body 31 associated with the pressing reliably inclines the posture toward the pressing area PA, and therefore contributes positively to the gripping . Further, since the particles 27 are not contained in the projections 32, the gripping can be ensured from the first time.

  Although the occupied volume V27 becomes smaller than before suction by internal suction, since the projections 32 are provided on the outer surface 31s of the bag body 31, internal suction such as the projections accommodating the particles 27 inside There is no decrease in volume due to Therefore, the gripping stability is higher.

  Depending on the size and / or posture of the object to be held placed on the supply stand 11, the projections 32 may abut the supply stand 11, but since the projections 32 can be inclined by elastic deformation of the bag body 31, they are pressed as they are You may recommend. Even if the projection 32 is inclined in a direction different from the pressing area PA side, the projection 32 in the inclined attitude is biased by the supply stand 11 and the bag body 31 which is elastically deformed. Therefore, after the internal suction is performed and the bag 26 is displaced upward after the internal suction and separated from the supply stand 11, the projection 32 is similarly inclined to the pressing area PA side as compared to the initial state. Therefore, the gripping function excellent in gripping stability is exhibited with respect to various gripping objects.

  The projections 32 are provided in a state in which the tips 32t are directed to the pressing area PA side, so that the projections 32 become more inclined to the pressing area PA side with the pressing, and the gripping stability is further improved.

  Since the tips 32t of the two projections 32 are farther from the connection point PB1 at one end than the connection point PB1 at the other end, ie, between the connection points PB1, they are gripped in the pressing area PA when lowering the bag 26 The object 12 is introduced more smoothly and gripping is performed quickly.

  In this example, since the bag body 31 and the protrusion 32 are formed of the same material, the protrusion 32 is difficult to be detached from the bag body 31 even if the posture change is repeated, and the durability as the bag 26 is excellent. In addition, when the projection 32 is elastically deformed as in this example, even when the projection 32 is in contact with the supply base 11 as in the case where the object to be gripped is small, the object to be gripped is securely gripped. Can.

  Since the occupied volume V27 in the initial state is 0.2 × V31 or more, the posture of the projection 32 at the time of internal suction is more stable and the gripping is more reliable and stable than in the case of less than 0.2 × V31. To last. When the occupied volume V27 in the initial state is 0.9 × V31 or less, a gripping function with excellent gripping stability is exhibited for a wide variety of gripping objects as compared to the case where the occupied volume V27 is larger than 0.9 × V31. Ru.

  The through hole 28 c is located at the center of the base 28, so that the negative pressure on the pressing area PA is equalized under internal suction as described above, so that the gripping force is more evenly applied to the gripping object 12, The grip is more stable.

  The arm drive unit 36 drives the arm unit 16 under the control of the arm control unit 37, thereby gripping the object to be grasped 12 and moving the bag 26 in a state of being on the receiving table 13 to a second three-dimensional coordinate. . The gripping device 17 guided to the second three-dimensional coordinates lowers the gripper 18 by sliding down the shaft 23 b and places the gripping object 12 on the receiving table 13.

  The internal suction is released to fluidize the particles 27. As a result, the pressing area PA of the bag body 31 returns to the shape in the initial state, and the projections 32 also return to the posture in the initial state before pressing. This releases the grip. Thus, the gripping object 12 is transported from the supply stand 11 to the receiving stand 13.

  The change in the posture of the projection 32 returning to the initial state when releasing the grip is due to the property of elastic deformation of the bag body 31 and the change in density of the particles 27 in the bag body 31. Therefore, as compared with the protrusion which accommodates the particles 27 inside and changes the posture by utilizing the density change of the particles 27 inside itself, the protrusions 32 have a posture in the initial state reliably at the time of releasing the grip. Return to As a result, the object to be grasped 12 is quickly released from grasping, and the next grasping is performed easily and reliably.

  The gripping device 17 that has released the gripping moves to the first three-dimensional coordinate based on the position of the gripping target 12 to be gripped next on the supply table 11 by the arm unit 16 and similarly grips the gripping target 12. As described above, the gripping on the supply table 11 and the gripping release on the receiving table 13 are repeatedly performed, and the gripping object 12 is transported one after another.

  The gripper as a gripping tool is not limited to the above example. The gripper 46 shown in FIG. 6 includes a bag 47, a base 48, and granules 27 (see FIG. 3A). The bag 47 includes a deformable bag main body 51 as a member main body and a projection 32. In addition, in FIG. 6, in order to avoid the complication of a figure, illustration of the granule 27 is abbreviate | omitted.

  The bag body 51 has a cylindrical portion 51a which is a cylindrical shape having an oval cross section, and a bottom portion 51b which closes one of the cylindrical portions 47a to form the bag body 51 in a bag shape. Of the outer surface 51s of the bag body 51, two projections 32 are provided on the outer surface 51s of the cylindrical portion 51a. The two protrusions 32 are formed to project at a distance, thereby forming a pressing area PA on the outer surface 51s between each other. Thus, the protrusion 32 may be provided on the cylindrical portion 51a. In this example, two protrusions 32 are arranged side by side in the longitudinal direction orthogonal to the circumferential direction of the cylindrical portion 51a, and the pressing area PA has a long shape in the longitudinal direction of the cylindrical portion 51a.

  The pressing area PA of the bag body 51 has a convex shape on the outer side, and the pressing area PA of the outer surface 51s also has a convex surface on the outer side. As described above, as long as the pressing area PA of the outer surface 51s has a curved shape that is convex outward, the protrusion 32 may be provided on the cylindrical portion. In this example, the shaft 23b (see FIG. 2) of the gripper holding portion 23 is replaced with an L-shaped shaft (not shown) in which the lower side of the shaft 23b in FIG. The gripper holding portion is not limited to this.

  It is preferable that at least the pressing area PA of the bag body 51 be smaller than the other portions, as in the case of the bag body 31 described above. As a result, the projection 32 inclines more reliably to the pressing area PA side as the pressing is performed. In this example, the thickness T31 makes the inner region of the circle (elliptic) RLc inscribed in each protrusion 32 smaller than the other regions, and thereby, the posture of the protrusion 32 is more surely on the pressing region PA side. I try to lean. As in the case of the bag body 31 described above, the area extending linearly in the vertical direction in FIG. 6B at the center of one projection 32 and the other projection 32 is thicker than the other area. Even if T31 forms a small portion, the posture change of the projection 32 has the same effect.

  The bag body 51 has a shape extending in the left-right direction of FIG. Therefore, the cylindrical portion 51a having an elliptical cross-section has a diameter D2 in the vertical direction in the case where the pressing area PA is directed downward in FIG. 6A is the major axis of the ellipse, and the minor diameter D2 Greater than. As a result, even with the bag body 51 extended as described above, that is, the bag body 51 formed to be elongated, it is difficult for the bag body 51 to collapse into a non-suckable state due to internal suction.

  Although the base 28 in FIG. 3A is provided to face the pressing area PA, the positional relationship between the base and the pressing area PA is not limited thereto. For example, the base 48 shown in FIG. 6 is provided in a state of closing the opening 51 c of the bag body 51, and unlike the base 28 of FIG. 3A, is provided in a vertical posture with respect to the pressing area PA. The through hole 48a connected to the vacuum pump 22 (see FIGS. 2 and 3A) of the base 48 is formed at a position close to the upper direction in FIG. 6A. Thereby, the difference in distance from each projection 32 is made as small as possible. This is to make the negative pressure generated by the vacuum pump 22 as equal as possible to the entire area of the pressing area PA in the internally sucked state. As described above, it is preferable that the through holes 48c in the case where they are provided in a posture that intersects the pressing region PA in a vertical posture or the like, be formed at a position where the difference in distance with each protrusion 32 is as small as possible. The other configuration and operation of the gripper 46 are the same as those of the gripper 18, and therefore the description thereof is omitted.

  The shape of the protrusions is not limited to the conical or truncated cone shape. For example, it may be cylindrical as shown by a projection 61 shown in FIG. The protrusion 61 is a cylindrical shape having a circular cross section, but may have a cylindrical shape having an elliptical cross section. The height h of the protrusion 61 may be a distance from the center of gravity PG of the bottom surface to the center of gravity of the tip 61 t formed in a planar shape, as in the case of the protrusion of the truncated cone.

  Also, as in the case of the projection 64 shown in FIG. 8, the cylindrical tip portion 64 p may be formed in a spherical shape. The height h of the projection 64 may be a distance from the center of gravity PG of the bottom surface defined similarly to the case of the projection 32 to the center of gravity of the tip 64t. 7 to 17 show an example using the bag body 31 shown in FIGS. 2 and 3A as the bag body, but as described above, even if the bag body 51 or other bag bodies are used. Good.

  When the protrusions 61 and 64 are provided in a posture in which the tip 61 t and the tip 64 t are directed to the pressing area PA side, the distance between the tips is narrower than the pressing area PA. , I.e., in the vertical position in FIGS. 7 and 8, provided on the bag body 31. Thus, coexistence of the ease of introduction of the object to be gripped 12 into the pressing area PA and the change of the posture due to the pressing of the protrusions 61 and 64 is achieved.

  The surfaces of the above-mentioned projections 32, 61, 64 are curved on the pressing area PA side, but may be projections having flat surfaces on the pressing area PA side. This is because there is a high probability that the contact area with the grasped object 12 will be larger. For example, the projection 67 shown in FIG. 9 is in the shape of a triangular pyramid, and one of the surfaces forming the side surface of the triangular mass 67s is provided in a state of facing the other projection (not shown). Thereby, the surface 67s on the pressing area PA side is a flat surface. Note that the projection 67 also has a rounded tip 67t in order to secure a larger contact area with the object to be gripped 12 similarly to the projection 32, but it may be a sharp tip.

  The protrusion 71 shown in FIG. 10 is formed in a wedge shape having a triangular cross section, and like the protrusion 67, a surface 71s on the pressing area PA side is formed in a flat surface. In addition, although the protrusion 71 is also rounded to the front-end | tip 71t which is a vertex of a cross-sectional triangle, it may be a sharp front-end. Further, the protrusion 74 shown in FIG. 11 is provided with a triangular plate-like facing member 74a provided in a posture facing the other protrusion (not shown) and a posture standing up with respect to the bag main body 31, And a supporting member 74b for supporting the member 74a. Thereby, also in the protrusion 71, the surface 67s on the pressing area PA side is flat as in the case of the protrusion 67 and the protrusion 71. A flat surface may be formed on the surface on the pressing area PA side of the conical and cylindrical protrusions by making the surface on the pressing area PA side of the projections 32, 61, 64 into a flat shape. . When the bag main body 31 is provided with the posture along the pressing direction to facilitate the introduction of the object to be gripped 12 into the pressing area PA as in the case of the protrusions 61 and 64 described above, the tip 61 t , 64t side is preferably thin (tapered), and at least the tip 61t, 64t side of the surface on the pressing area PA side is cut out in a planar shape. Thereby, the distance between the tips 61t and the distance between the tips 64t become larger, and as a result, the ease of introduction of the pressing area PA of the object to be grasped 12 is also secured. From the viewpoint of facilitating such introduction of the object to be gripped 12 into the pressing area PA, for example, the protrusions 32 and the like may be provided on the bag body 31 in a posture largely inclined to the pressing area PA side. In a more tapered state, at least the region on the tip 32t side of the surface on the pressing region PA side may be cut out in a planar shape. In that case, a plane parallel to the pressing direction, or a plane in which the tip 32t is inclined to the side opposite to the pressing direction with respect to the pressing direction.

  In order to make the posture of the protrusion fall more easily and reliably to the pressing region PA side, a notch may be formed on the side opposite to the pressing region of the protrusion. For example, in the protrusion 77 shown in FIG. 12A, a notch 74c is formed in the support member 74b of the protrusion 74 shown in FIG. The notch 74c is formed in a region from the side opposite to the pressing region of the support member 74b to the side facing the opposing member 74a, to a region substantially to the center of the support member 74b. As a result, the projection 77 can be more easily inclined to the pressing area PA. In this example, the number of cuts 74c is three, but may be one or a plurality other than three. Such a cut may be formed in a projection having another shape, such as the projections 32, 61, 64, 67, 71 described above. For example, the projection 78 shown in FIG. 12B is an aspect in which the cut 71c is formed in the above-mentioned hook-shaped projection. Similarly, the cut 71 c is formed from the side surface on the side opposite to the pressing area toward the pressing area PA.

  The height h (not shown) of each projection 67, 71, 74. 77, 78 shown in FIGS. 9 to 12B is a plane defined in the same manner as the projection 32, that is, the connection point PB1 on the pressing area side (see FIG. The distance from the center of gravity PG of the plane passing through 5) and the connection point PB2 on the opposite side of the pressing area (see FIG. 5) to each tip 67t, 71t, 74t, 77t, 78t may be used. In addition, the protrusions are not limited to these examples, and in the case of protrusions that are elastically deformed, the strength of the protrusions may be improved by inserting a hard core material such as metal, for example. For example, it may be an airtight protrusion whose inside is hollow and whose hollow part is independent of the internal space of the bag main bodies 31, 51. In that case, the hollow portion of the protrusion may be connected to a gas supply unit (not shown) that supplies gas, and after pressing, the protrusion may be gripped by supplying gas to the hollow portion of the protrusion. The hollow portion of the protrusion and the gas supply portion may be connected, for example, by a pipe that penetrates the inside space of the bag bodies 31 and 51.

  The number of projections may be plural and is not limited to two. In addition, although the example which used the processus | protrusion 32 as a processus | protrusion is shown in FIGS. 13-17, as mentioned above, other processus | protrusions, such as processus | protrusion 61, 64, may be sufficient. The bag 80 shown in FIG. 13 differs from the bag 26 in that the number of protrusions 32 is three. Three projections 32 are disposed at each vertex of a generally equilateral triangle. Since these three projections 32 form a pressing area PA therebetween, the formed pressing area PA is drawn as a rounded triangle in FIG. 13 as an area surrounded by these projections 32. There is. The thickness T31 makes the inner region of the circle RLc inscribed in each protrusion 32 smaller than the other regions.

  Also, the bag 83 shown in FIG. 14 differs from the bag 26 in that the number of projections 32 is eight. The eight protrusions 32 are disposed at each vertex of a generally regular octagon, and form a pressing area PA between each other. As the number of the set of projections forming the pressing area PA increases, the pressing area PA to be formed approaches a perfect circle. Therefore, in FIG. 14, the formed pressing area PA is drawn as a perfect circle. Also in this example, as in the example shown in FIG. 13, the thickness T31 makes the inner region of the circle RLc inscribed in each protrusion 32 smaller than the other regions. As described above, the number of the projections 32 forming one set may be two or more, and these are arranged on one circle when viewed from the lower side as shown in FIG. 3A, FIG. 13 and FIG. Is preferred. When the diameter of the bottom portion 31b of the bag body 31 is D0 mm and the number of projections 32 forming one set is n, it is preferable to satisfy the following condition (1). In the following conditions, each unit of d and h is mm.

(1) D1 / 2> h and D1 × 0.5> n × d
The number of sets of protrusions forming the pressing area PA is not limited to one. For example, in the bag 86 shown in FIG. 15, the bag body 31 includes a first set of two projections 32A, a second set of two projections 32B, and a third set of two projections 32C. It is provided. Thus, the number of sets formed by the plurality of protrusions may be more than one. The shapes of the protrusions 32A to 32C are the same as the protrusions 32.

  A first pressing area PA1 is formed by the first set of protrusions 32A, a second pressing area PA2 is formed by the second sets of protrusions 32B, and a third pressing area PA3 is formed by the third sets of protrusions 32C. The protrusions 32A, the protrusions 32B, and the protrusions 32C are provided on the same straight line as shown in FIG. 15 (B) when viewed from the lower side of the bag body 31 in FIG. 15 (A). The protrusions 32A are disposed at the same positions as the protrusions 32 in FIG. 3A, and as shown in FIG. 15B, the protrusions 32B are disposed inside the protrusions 32A and the protrusions 32C are disposed inside the protrusions 32B. There is. Therefore, the second pressing area PA2 is formed inside the first pressing area PA1, and the third pressing area P3 is formed inside the second pressing area PA2. Thus, the pressing areas may be formed in an overlapping manner.

  In this example, the positions in the pressing direction of the projection 32A, the projection 32B, and the tips 32t of the projection 32C (see FIG. 4 and the like) are equal to each other. However, the protrusions 32A, the protrusions 32B, and the protrusions 32C may be protruded in the pressing direction in the order of the protrusions 32C, the protrusions 32B, and the protrusions 32A. As described above, in the case where a plurality of pressing areas are conceived, when the thickness T31 of the bag body 31 is unevenly formed, the thickness T31 is based on the outermost pressing area (in this example, the first pressing area PA1). It is good to decide That is, it is preferable to form the outermost pressing region smaller in thickness T31 than the other regions, and in this example, the inner region of the circle RLc inscribed in the projections 32A is formed thinner than the other regions.

  It is preferable that at least the projections 32B and the projections 32C elastically deform, and in this example, all the projections 32A to 32C elastically deform. Thus, the object to be grasped 12 (see FIG. 2) is held by the projections 32A, and via the projections 32B and the projections 32C in a state of being elastically deformed at a position above this holding position and the bag body 31. , Is gripped by the solidified particles 27.

  In this example, the object to be grasped is grasped by the granular material 27 via the bag body 31 in any of the first pressing area PA1, the second pressing area PA2 and the third pressing area PA3 and the protrusion It holds in any set of 32A, projections 32B and projections 32C. Therefore, a gripping function with excellent gripping stability is exhibited for a wide variety of gripping objects.

  The protrusions 32A, the protrusions 32B, and the protrusions 32C are not limited to the arrangement on the same straight line as shown in FIG. 15 (B). For example, in the bag 89 shown in FIG. 16, the arrangement direction of the two protrusions 32A, the arrangement direction of the two protrusions 32B, and the arrangement direction of the two protrusions 32C are from the lower side as in FIG. When seen, they cross each other.

  In this example, the bag is manufactured by adhering the projections 32A to 32C to the bag body 31. In the case where the projections 32A to 32C are formed by adhesion in this manner, the joint between the projections 32A to 32C and the bag body 31 is often hard. Therefore, as described above, the direction in which the projections 32A to the projections 32C forming each group are arranged cross each other, thereby making the bag body 31 more resistant to breakage even when gripping and releasing the grip are repeated. .

  Even in the case where the number of sets of protrusions is plural, the number of protrusions constituting each set is not limited to two, and may be at least two. For example, in the bag 92 shown in FIG. 17, the first set of projections 32A is eight, the second set of projections 32B is six, and the third set of projections 32C is four. It is provided in the main body 31. The projections 32A, the projections 32B, and the projections 32C form a pressing area for each set, but in FIG. 17, the pressing areas are not shown in order to avoid complication of the drawing.

  Similar to FIG. 15B, the eight protrusions 32A are arranged at substantially equal intervals on the first circle C1 as shown in FIG. 17 as viewed from below. Similarly, the six protrusions 32B are arranged at substantially equal intervals on a second circle C2 smaller than the first circle C1. The number of projections 32A on the first circle C1 is preferably larger than the number of projections 32B on the second circle C2 as in this example. The first circle C1 and the second circle C2 are preferably concentric circles, and this is also the case in this example. This further improves the gripping stability. The protrusions 32A and the protrusions 32B are disposed at an angle to each other with the centers of the first circle C1 and the second circle C2 in FIG. 17 as the rotation centers so that the protrusions 32A and the protrusions 32B are not on the same straight line. It is made to be able to withstand repeated gripping and gripping cancellation.

  The protrusions 32C are arranged at substantially equal intervals on a third circle C3 smaller than the first circle C1 and the second circle C2. Similarly, it is preferable that the number of projections 32A on the first circle C1 and the number of projections 32B on the second circle C2 be larger than the number of projections 32C. Similar to the relationship between the first circle C1 and the second circle C2, the third circle C3 is preferably concentric with the first circle C1 and / or the second circle, and in the present example, the first circle C1 and the second circle C1 It is concentric with 2 yen C2. Similarly, the protrusions 32C are arranged at an angle to each other with the centers of the first circle C1 to the third circle C3 in FIG. 17 as the rotation centers so that the protrusions 32A and the protrusions 32C are not in the same straight line. Is preferred, and in this example it is. The protrusions 32A to 32C are preferably positioned so that the center of gravity PG of each bottom surface is on the first circle C1 to the third circle C3, and this is also the case in this example. As described above, the number of sets of protrusions may be plural, and in this case, when the number of sets is N, it is preferable to satisfy the following condition (2).

(2) D0 / 2> (d / 2) × N × 2
Further, in this example also, a plurality of pressing areas can be conceived, so when the thickness T31 of the bag main body 31 is unevenly formed, the thickness T31 is based on the outermost pressing area formed by the projections 32A. It is good to decide That is, it is preferable to form the thickness T31 smaller than the other regions in the outermost pressing region. In this example, the inner region of the circle RLc inscribed by the projections 32A is formed thinner than the other regions.

  In each of the above examples, the pressing area PA is formed by providing the plurality of projections on the outer surface of the bag main body with a gap, and the pressing area PA is set in advance in the bag main body. A plurality of projections may be provided inside and / or outside of the pressing area PA. For example, a bag 95 as a gripping member shown in FIG. 18 includes a bag 31 and a plurality of projections 96 in the shape of a spherical crown (hemisphere), and the projections 96 are provided inside a pressing area PA set in advance. In this example, the protrusion 96 is also provided at the center of the pressing area PA, and the configuration other than the shape of the protrusion 96 is the same as that of the bag 92 of FIG. Therefore, in FIG. 18, all the protrusions 96 are schematically drawn in the same semi-cross section of the same size, but the arrangement of the protrusions 96 forming the three sets is similar to the bottom view of FIG. The number of projections 96 forming each set is not limited to this example, and the projections 96 at the center of the pressing area PA may be absent. In addition, the projection 96 is not limited to a spherical crown, and may have another shape such as conical or pyramidal, but the tip is rounded in order to secure a larger contact area with the object 12 to be grasped. Is preferred.

DESCRIPTION OF SYMBOLS 10 conveyance machine 11 supply stand 12 holding target object 13 receiving stand 13a conveyor 16 arm part 16a-16d arm 16e turning mechanism 17 holding | grip apparatus 18,46 gripper 21 support stand 22 vacuum pump 23 gripper holding part 23a main-body part 23b axis 23c connection part Reference numerals 26, 47, 80, 83, 86, 89, 92, 95 Bags 27 Particulates 28, 48 Bases 28a Central 28b Outer peripherals 28c, 48c Through holes 31, 39, 40, 51 Bag body 31a, 51a Tube 31b, 51b Bottom 31c, 51c Opening 31s, 51s Outer surface 32, 32A to 32C, 61, 64, 67, 71, 74, 77, 78 Protrusion 32t, 61t, 64t, 67t, 71t, 74t, 77t, 78t Tip 33 Suction control unit 36 Arm drive unit 37 Arm control unit 38 Ripper position detector 41 filter 63p tip 67s, 71s, 74s surface 71c, 74c notches 74a facing member 74b supporting member d diameter of diameter D2 cylindrical portion of diameter D1 yen RLb projections (long diameter)
D3 Diameter of tube (short diameter)
h Protrusion height PA Pressing area PA1 to PA3 1st pressing area to 3rd pressing area PB1, PB2 Connection point PG Gravity center of projection bottom PL1 Projection plane PL2 Plane PM Midpoint PP1, PP2 Projection point RLa, RLb, RLc Circle TA Thin film area T31 Thickness of bag body

Claims (9)

In a bag-like gripping member that grips the object to be grasped by pressing the object to be grasped in a state in which the particles are contained, and the internal gas being sucked,
A deformable bag-like member main body formed with an opening for containing the particles;
A plurality of spaced apart projections provided on the outer surface of the member body;
A gripping member in which a region between the plurality of projections of the outer surface is a curved surface that is convex outward.   The gripping member according to claim 1, wherein the plurality of protrusions form a pressing region for pressing the gripping object between the mutual surfaces of the outer surfaces.   The gripping member according to claim 2, wherein the protrusion is provided in a state in which the tip is directed to the pressing area side.   The gripping member according to claim 2, wherein a surface of the projection on the side of the pressing area is formed in a flat surface.   The gripping member according to any one of claims 1 to 4, wherein the protrusion is elastically deformed. The plurality of protrusions are respectively provided on two circles which are concentric circles,
The gripping member according to claim 5, wherein the number of the protrusions in one of the two circles is larger than the number of the protrusions in the other small circle. A gripping member according to any one of claims 1 to 6,
A gripping tool comprising: the granular material accommodated in the member body of the gripping member.   The holding tool according to claim 7, further comprising a support member provided to support the holding article and close the opening of the holding member. The gripping tool according to claim 7 or 8;
A suction unit for suctioning gas inside the gripping member;
A gripping device comprising:

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