JP2021061688A - Electrostatic attraction device and manufacturing method of contact member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the suction force to an object having a rough surface and to hold the object securely. An electrostatic suction device ED includes a contact member 11 made of a dielectric having a contact surface 11f that can be deformed according to a surface OBf of a cardboard container OB, and a pair of electrodes capable of applying a voltage to the contact member 11. 12 and 13, and the contact surface 11f is a concavo-convex portion 15 in which concave portions and convex portions are continuous in any one direction along the surface and in both the intersecting directions along the one direction. Has. [Selection diagram] Fig. 1

Description

The present invention relates to an electrostatic adsorption device and a method for manufacturing a contact member.

The electrostatic adsorption device described in Patent Document 1 includes a deformable surface for contacting the surface of an object (article), and a pair of electrodes for applying a voltage to the surface. In this device, it is said that an electrostatic attraction force (electrostatic force) for an object is generated by a potential difference between a pair of electrodes.

Japanese Patent No. 5038405

When the electrostatic adsorption device described in Cited Document 1 was verified, the adsorption force (electrostatic adsorption force) required by the inventors could not be obtained. Further, for example, when the object is a cardboard container, the surface thereof has fine irregularities, so that even a deformable surface such as the electrostatic adsorption device of Patent Document 1 is placed between the object and the object. There is a problem that many gaps remain and it is not possible to obtain sufficient adsorption force for the object. In addition, the weight is increased by accommodating the article inside the cardboard container. Therefore, it is desired to increase the adsorption force by electrostatic adsorption even for an object having a rough surface such as a cardboard container.

The present invention provides an electrostatic adsorption device capable of increasing the adsorption force on an object and reliably holding the object, and a method for manufacturing a contact member made of a dielectric used in the electrostatic adsorption device. With the goal.

The electrostatic adsorption device according to the aspect of the present invention includes a contact member made of a dielectric having a contact surface that can be deformed according to the surface of an object, and a pair of electrodes capable of applying a voltage to the contact member. The contact surface has a concavo-convex portion in which a concave portion and a convex portion are continuous in any one direction along the surface and in both the intersecting directions intersecting the one direction and along the surface.

Further, the pair of electrodes may be provided in contact with the contact member and may be deformable together with the contact member. Further, the surface roughness of the contact surface due to the uneven portion may be smaller than the surface roughness of the surface of the object. Further, the contact surface may have a maximum height roughness Rz of the surface roughness due to the uneven portion of 0.1 μm or more and 7.0 μm or less. Further, the contact surface may have an average length AR of the roughness motif of 90 or less in the motif parameter of the surface roughness due to the uneven portion. Further, on the contact surface, the average value of the height difference between the concave portion and the convex portion in the uneven portion may be smaller than the average value on the surface of the object. Further, the shear frictional force generated between the object and the contact surface in the state where the surface of the object is adsorbed may be 3.0 mN / mm ² or more. Further, the contact surface may be formed by being transferred by using a transfer type having a transfer surface formed by surface processing by shot blasting.

The method for manufacturing a contact member according to an aspect of the present invention is a method for manufacturing a contact member provided in an electrostatic adsorption device that adsorbs an object and having a contact surface that can be deformed according to the surface of the object. Includes forming irregularities on the transfer surface of the transfer type, supplying a liquid dielectric material for forming the contact member onto the transfer surface to solidify it, and removing the contact member from the transfer surface. ..

Further, it may include forming irregularities on the transfer surface by colliding the particles with the transfer surface of the transfer type. The material of the granules may be SUS (stainless steel) or iron, and the particle size may be 0.2 mm to 0.3 mm. Further, the transfer type has an outer frame member that projects upward from the transfer surface and surrounds the transfer surface on the outer peripheral side of the transfer surface, and includes supplying a liquid contact member material to the inside of the outer frame member. But it may be.

According to the electrostatic adsorption device according to the aspect of the present invention, by applying a voltage to the contact member with a pair of electrodes, the contact member generates an electrostatic force and adsorbs an object. In the state where the object is adsorbed by electrostatic force, when the surface of the object is rough, the contact surface of the contact member is deformed following the surface of the object, and in addition, the uneven portion of the contact surface is formed. The ratio of the concave portion and the convex portion to the concave portion and the convex portion on the rough surface of the surface of the object is high, and the contact area becomes large. As a result, the adsorption force (electrostatic adsorption force) on the object becomes large, and the object is firmly adsorbed. Therefore, the object is reliably held.

Further, in the form in which the pair of electrodes is provided in contact with the contact member and can be deformed together with the contact member, the pair of electrodes is deformed together with the contact member, so that the contact member is deformed following the surface of the object. It can enhance the sex. Further, in the form in which the surface roughness due to the uneven portion of the contact surface is smaller than the surface roughness of the surface of the object, when the contact surface comes into contact with the surface of the object, the concave portion and the convex portion of the uneven portion are targeted. Since it fits well to the unevenness of the object, the gap formed between the contact surface and the object is small, the contact area between the contact surface and the surface of the object is large, and the adsorption force to the object is large. Further, in the form in which the maximum height roughness Rz of the surface roughness due to the uneven portion on the contact surface is 0.1 μm or more and 7.0 μm or less, the contact between the uneven portion of the contact surface and the surface of the object is good. .. Further, in the form in which the average length AR of the roughness motif in the motif parameter of the surface roughness due to the uneven portion on the contact surface is 90 or less, the contact between the uneven portion of the contact surface and the surface of the object is good.

Further, in a form in which the average value of the height difference between the concave portion and the convex portion on the contact surface is smaller than the average value on the surface of the object, the uneven portion of the contact surface and the surface of the object The contact condition is good. Further, in the form in which the shear frictional force generated between the object and the contact surface in the state where the surface of the object is adsorbed is 3.0 mN / mm ² or more, the contact surface does not easily come off from the surface of the object. The object is securely held. Further, in the form in which the contact surface is transferred and formed by using a transfer mold having a transfer surface formed by surface processing by shot blasting, a contact surface having an appropriate uneven portion is realized. Further, in a form in which a holding member for holding the contact member is further provided and the holding member has a holding surface for holding the contact member, the contact member is held by the holding surface, so that the deformable contact member is reliably held. At the same time, the contact surface comes into contact with the object in a well-balanced manner.

According to the method for manufacturing a contact member according to an aspect of the present invention, a contact member is formed by solidifying the liquid dielectric material supplied on the transfer surface, and the contact member has irregularities formed on the transfer surface. Is transcribed. As a result, a contact member having a contact surface having an uneven portion can be easily formed.

Further, in a form including forming irregularities on the transfer surface by colliding the particles with the transfer surface of the transfer type, the irregularities on the transfer surface can be easily formed. Further, in the form in which the material of the granules is SUS or iron and the particle size is 0.2 mm to 0.3 mm, the unevenness of the transfer surface can be formed with high accuracy. Further, the transfer type includes an outer frame member that projects upward from the transfer surface and surrounds the transfer surface on the outer peripheral side of the transfer surface, and supplies a liquid dielectric material to the inside of the outer frame member. In the embodiment, the outer circumference of the contact member can be defined by the outer frame member while forming a predetermined uneven portion on the contact surface of the contact member. Further, the thickness of the contact member can be easily defined by the height of the outer frame member.

It is a figure which shows an example of the electrostatic adsorption device which concerns on embodiment. It is a figure which shows an example of the cross section of the concavo-convex portion formed on the contact surface of the contact member in an electrostatic adsorption device. It is a top view which shows an example of a pair of electrodes in an electrostatic adsorption device. It is a flowchart which shows an example of the manufacturing method of a contact member. It is sectional drawing which shows an example of the transfer type used in the manufacturing method of a contact member. It is sectional drawing which shows the mold material for forming a transfer mold. It is sectional drawing which shows the state which performed the processing by shot blasting on the upper surface of a mold material, and formed the transfer surface of a transfer type. It is sectional drawing which shows the state which supplied the contact member material on the transfer surface of a transfer type. It is sectional drawing which shows the state which made the contact member by solidifying the contact member material on the transfer surface. It is sectional drawing which shows the state which takes out the contact member from the transfer surface of a transfer type. It is an observation image which shows the contact surface of the suction pad formed under the condition of Example 1. FIG. It is an observation image which shows the contact surface of the suction pad formed under the condition of the comparative example 2. It is an observation image which shows the contact surface of the suction pad formed under the condition of the comparative example 3. FIG. It is a figure which shows the shear friction force for each pattern of the electrode in the state which electrostatically adsorbed the cardboard container in an Example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to this form. In addition, in order to explain the embodiment, the drawings are expressed by changing the scale as appropriate, such as by enlarging or emphasizing a part, and the size, shape, etc. may differ from the actual product. ..

FIG. 1 is a diagram showing an example of the electrostatic adsorption device ED according to the embodiment. As shown in FIG. 1, the electrostatic adsorption device ED according to the present embodiment includes an adsorption pad AP, a pad holding member PH, and a voltage application unit PS. The electrostatic adsorption device ED, for example, electrostatically adsorbs a cardboard container (object) OB as an object. The electrostatic suction device ED sucks and holds the cardboard container OB with the suction pad AP.

The electrostatic adsorption device ED is not limited to the cardboard container OB, and can adsorb and hold an object having a rough surface such as a veneer plate or concrete. Further, the electrostatic adsorption device ED can be used to adsorb and hold an object having a smooth surface as well as an object having a rough surface.

The suction pad AP is composed of a pad end portion AP1 and a pad base portion AP2, and the pad end portion AP1 includes a contact member 11 and a pair of electrodes 12 and 13 capable of applying a voltage to the contact member 11. The pair of electrodes 12 and 13 are provided between the pad base AP2 and the contact member 11. The contact member 11 has a contact surface 11f facing the surface OBf of the cardboard container OB on one surface side located on the side opposite to the pad base AP2 and the pair of electrodes 12 and 13. The pad end AP1 is a layer from the pair of electrodes 12 and 13 to the contact surface 11f. The pad base AP2 is a layer other than the pad end AP1 in the suction pad AP. By applying a voltage to the pair of electrodes 12 and 13, an electrostatic suction force is generated on the contact surface 11f of the contact member 11, and the suction pad AP sucks the cardboard container OB. The contact member 11 has, for example, a rectangular contact surface 11f, and one side is set to about 10 mm to 500 mm. Further, the contact member 11 may be provided in a disk shape in addition to the rectangular shape, and may be set to, for example, an outer diameter of about 10 mm to 500 mm. The thickness of the contact member 11 is set to, for example, about 30 μm to 800 μm. In the present embodiment, the contact member 11 has a thickness of, for example, about 80 μm.

At least the contact surface 11f of the contact member 11 can be deformed in accordance with the surface OBf of the cardboard container OB. In the present embodiment, the suction pad AP as a whole can be deformed according to the surface OBf of the cardboard container OB, but the suction pad AP is not limited to this embodiment. For example, in the thickness direction connecting the contact surface 11f of the contact member 11 and the pair of electrodes 12 and 13 (direction orthogonal to the contact surface 11f), only a part of the contact surface 11f side follows the surface OBf of the cardboard container OB. It may be deformable.

The adsorption pad AP is formed of a dielectric material and has both properties as a dielectric and properties as an insulator. The suction pad AP can suck on both the insulator and the conductor by applying a predetermined voltage to the pair of electrodes 12 and 13. For example, ^{a material having a resistivity greater than about 10 12} Ω · cm may be defined as an insulator. Also, for example, ^{a material having a resistivity less than about 10 12} Ω · cm may be defined as a conductor. Further, the suction pad AP is made of a dielectric material having elasticity and flexibility that can be deformed according to the surface OBf of the cardboard container OB. In the present embodiment, the suction pad AP is shown and described separately for the pad end AP1 and the pad base AP2 for the convenience of the manufacturing method described later, but it is used for the pad end AP1 and the pad base AP2. The dielectric material is the same material.

The dielectric material is not limited to a material that makes the formed suction pad AP elastically deformable. For example, as the dielectric material for forming the adsorption pad AP, a material for forming a thin film or a layered body which is flexible but does not substantially elastically expand and contract may be used. Further, the dielectric material forming the adsorption pad AP preferably has, for example, a flexibility having an elastic modulus of less than 10 MPa, particularly an elastic modulus of less than 1 MPa.

Examples of such a dielectric material include rubber-based materials and resin-based materials. More specifically, examples of the dielectric material forming the adsorption pad AP include crosslinkable rubber, non-crosslinkable thermoplastic elastomer, and soft resin. Examples of the crosslinkable rubber used as the dielectric material for forming the adsorption pad AP include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), and butyl rubber (IIR). , Acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), acrylic rubber (ACM), chlorosulfonated polyethylene rubber (CSM), urethane rubber (U), silicone rubber (Q), Fluoro rubber (FKM), epichlorohydrin rubber (CO), polysulfide rubber (T), polydimethylsiloxane (PDMS) and the like.

The non-crosslinkable thermoplastic elastomer used as the dielectric material for forming the adsorption pad AP includes, for example, styrene-based, olefin-based, urethane-based, polyester-based, polyamide-based, polyimide-based, vinyl chloride-based, and fluorine-based. Examples thereof include various thermoplastic elastomers such as acrylics.

The soft resin used as the dielectric material for forming the adsorption pad AP includes, for example, ethylene vinyl acetate resin (EVA), soft polyester resin, low density polyethylene, polyurethane (PU), polypropylene (PP), acrylic resin and the like. However, a resin that is soft in itself can be mentioned, and various soft resins such as those obtained by adding a plasticizing agent to various resins to soften them can be applied.

Further, the dielectric material forming the adsorption pad AP may include various composite materials such as fiber reinforced plastic (FRP) using glass fiber or carbon fiber, glass, ceramic and the like.

FIG. 2 is a diagram showing an example of a cross section of the uneven portion 15 formed on the contact surface 11f of the contact member 11 in the electrostatic adsorption device ED. As shown in FIG. 2, the contact surface 11f of the contact member 11 has an uneven portion 15. The uneven portion 15 has a concave portion 15a that is recessed in a direction perpendicular to the surface direction of the contact surface 11f, and a convex portion 15b that protrudes in a direction perpendicular to the surface direction of the contact surface 11f. The concave portion 15a and the convex portion 15b are formed over the entire surface of the contact surface 11f. That is, the concave portion 15a and the convex portion 15b are continuously formed on the contact surface 11f in both an arbitrary direction along the surface and the intersecting direction intersecting the one direction and along the surface. ..

The concave portion 15a and the convex portion 15b may be formed regularly and continuously along one direction and the intersecting direction of the contact surface 11f, or may be formed irregularly (randomly) without regularity. Good. As the contact surface 11f having such uneven portions 15, as will be described in detail later, a transfer type TD having a transfer surface 51f formed by surface processing by shot blasting is used, and a transfer pattern of the transfer surface 51f of the transfer type TD is used. Is transcribed and formed.

It is preferable that the surface roughness of the contact surface 11f due to the uneven portion 15 is smaller than the surface roughness of the surface OBf of the cardboard container OB which is the object. As a result, when the contact surface 11f comes into contact with the surface OBf of the cardboard container OB, the concave portion 15a and the convex portion 15b are deformed so as to imitate the surface OBf of the cardboard container OB, and the uneven portion 15 of the contact surface 11f and the cardboard container OB The contact area with the surface OBf increases. By increasing the contact area, it is possible to suppress the formation of a gap between the surface OBf and the uneven portion 15, and the electrostatic adsorption force is increased.

Further, it is preferable that the maximum height roughness Rz of the surface roughness of the contact surface 11f due to the uneven portion 15 is 0.1 μm or more and 7.0 μm or less. By setting the maximum height roughness Rz of the contact surface 11f to 0.1 μm or more and 7.0 μm or less, the contact area between the surface and the contact surface 11f increases even if the surface of the object is a rough surface. Further, a more preferable range of the maximum height roughness Rz on the contact surface 11f is 1.0 μm or more and 5.0 μm or less. When the maximum height roughness Rz on the contact surface 11f is 1.0 μm or more and 5.0 μm or less, the contact area between the surface of the object and the contact surface 11f is further increased. Further, a more preferable range of the maximum height roughness Rz on the contact surface 11f is 4.0 μm or more and 5.0 μm or less. When the maximum height roughness Rz on the contact surface 11f is 4.0 μm or more and 5.0 μm or less, for example, the contact area of the object with respect to the surface OBf (rough surface) of the cardboard container OB or the like is particularly increased.

Further, it is preferable that the contact surface 11f has an average length AR of the roughness motif of 90 or less in the motif parameter (JISBO631) of the surface roughness due to the uneven portion 15. According to this form, it is possible to suppress the formation of a gap between the surface of the object and the uneven portion 15, and the contact area between the surface of the object and the contact surface 11f is increased. Further, it is preferable that the average value of the height difference between the concave portion 15a and the convex portion 15b in the concave-convex portion 15 of the contact surface 11f is smaller than the average value of the uneven height on the surface OBf of the cardboard container OB. According to this form, it is possible to prevent a large gap from being generated between the surface of the object and the uneven portion 15, and the contact area between the surface of the object and the contact surface 11f is increased.

As described above, since the uneven portion 15 is formed on the contact surface 11f of the contact member 11, when the contact surface 11f comes into contact with the surface OBf of the corrugated cardboard container OB which is the object, the concave portion 15a and the convex portion 15b become rough. It deforms along the surface OBf, which is a surface. Therefore, the contact surface 11f and the surface OBf come into contact with each other without an excessive gap (a state in which a gap is suppressed).

The contact surface 11f attracts the surface OBf of the cardboard container OB by the electrostatic adsorption force generated by applying a voltage to the pair of electrodes 12 and 13. In the state where the contact surface 11f adsorbs the surface OBf of the cardboard container OB, the contact member 11 is provided so that the shear frictional force generated between the cardboard container OB and the contact surface 11f is 3.0 mN / mm ^{2 or more.} It is preferable that the material is selected and the uneven portion 15 is formed. The suction pad AP having such a contact surface 11f has a high electrostatic suction force with respect to the target cardboard container OB.

The pair of electrodes 12 and 13 are used to apply a voltage to the contact member 11. As shown in FIG. 1, the pair of electrodes 12 and 13 are provided on the boundary surface 11g between the contact member 11 and the pad base AP2. The pair of electrodes 12 and 13 may be buried in the contact member 11. Further, the pair of electrodes 12 and 13 are provided not on the contact member 11 but on the pad base AP2 side, and when the pad end AP1 (in this case, the contact member 11) is attached to the pad base AP2, the contact member 11 It may be in contact with the boundary surface 11g. Further, the pair of electrodes 12 and 13 may be embedded in the pad base AP2. The pair of electrodes 12 and 13 are provided so as to face each other with a gap (see FIG. 3). A part of the contact member 11 or the pad base AP2, which is an insulator, is filled in the gap between the pair of electrodes 12 and 13. As a result, an insulating portion exists between the pair of electrodes 12 and 13.

FIG. 3 is a plan view showing an example of a pair of electrodes 12 and 13 in the electrostatic adsorption device ED. As shown in FIG. 3, the pair of electrodes 12 and 13 have electrode bases 12a and 13a and a plurality of electrode portions 12b and 13b, respectively. Each of the electrode base portion 12a and the electrode portion 12b, and each of the electrode base portion 13a and the electrode portion 13b are electrically connected. The plurality of electrode portions 12b and 13b are provided at intervals in the electrode width direction Da where the electrode base portions 12a and 13a extend. The electrode portions 12b and 13b extend in the electrode length direction Db orthogonal to the electrode width direction Da. The electrode portion 12b formed on one electrode 12 extends from the electrode base portion 12a toward the electrode base portion 13a of the other electrode 13 in the electrode length direction Db. The electrode portion 13b formed on the other electrode 13 extends from the electrode base portion 13a toward the electrode base portion 12a of one electrode 12 in the electrode length direction Db. As described above, the pair of electrodes 12 and 13 are comb-shaped, respectively, and are arranged so as to face each other in a plan view.

The electrode portion 12b of the electrode 12 is arranged between two electrode portions 13b adjacent to each other in the electrode width direction Da in the electrode 13. Further, the electrode portion 13b of the electrode 13 is arranged between two electrode portions 12b adjacent to each other in the electrode width direction Da in the electrode 12. As a result, the electrode portion 12b of the electrode 12 and the electrode portion 13b of the electrode 13 are alternately arranged at intervals in the electrode width direction Da.

In the pair of electrodes 12 and 13, it is preferable that a plurality of sets of electrode portions 12b and 13b adjacent to each other in the electrode width direction Da are provided. Further, it is preferable that the pair of electrodes 12 and 13 are provided with three or more sets of electrode portions 12b and 13b adjacent to each other in the electrode width direction Da. Further, it is particularly preferable that the pair of electrodes 12 and 13 are provided with six or more sets of electrode portions 12b and 13b adjacent to each other in the electrode width direction Da. In the pair of electrodes 12 and 13, the number (number of pairs) of the electrode portions 12b and 13b adjacent to each other in the electrode width direction Da is the outer diameter of the suction pad AP, the weight of the cardboard container OB which is the object, and the surface OBf. It is appropriately selected according to the roughness of the corrugated cardboard.

Further, in the pair of electrodes 12 and 13, in order to increase the number (number of sets) of the electrode portions 12b and 13b adjacent to each other in the electrode width direction Da within the range of the outer diameter of the contact surface 11f of the contact member 11, the electrode portions It is preferable that the width dimension W in the electrode width direction Da of 12b and 13b is small. For example, the width dimension W of the electrode portions 12b and 13b is preferably 10 mm or less. Further, in the width dimension W, a more preferable dimension is 8 mm or less, and a particularly preferable dimension is 6 mm or less. Similarly, in order to increase the number (number of sets) of the electrode portions 12b and 13b, it is preferable that the gap d is small in the electrode width direction Da of the electrode portions 12b and 13b. For example, the gap d between the electrode portions 12b and 13b is preferably 1 mm or less. Further, the more preferable size of the gap d is preferably 0.5 mm or less.

Such a pair of electrodes 12 and 13 may be provided on the boundary surface 11g of the contact member 11 and may be deformable together with the contact member 11. Therefore, for the pair of electrodes 12 and 13, for example, it is preferable that the conductive material including various metal materials is in the form of a thin film having a film thickness of 200 μm or less.

As shown in FIG. 1, the pad holding member PH holds the suction pad AP. The pad holding member PH is formed of an insulating material such as resin or a non-conductive metal material. Further, when the pad holding member PH is made of a conductive metal material or the like, an insulating material is interposed between the pad holding member PH and the suction pad AP. The pad holding member PH includes a mounting portion 21 that can be mounted on various machines.

The suction pad AP may be detachable from the pad holding member PH. According to this form, the suction pad AP can be replaced. The suction pad AP is attached to the pad holding member PH with, for example, a peelable adhesive.

As shown in FIG. 1, the voltage application unit PS applies a voltage to the contact member 11 of the suction pad AP. The voltage application unit PS is electrically connected to a power source (not shown), and applies a predetermined voltage to the pair of electrodes 12 and 13. The voltage application unit PS includes wirings 31A and 31B provided in the pad holding member PH and pad base AP2, and connectors 32A and 32B provided at the tips of the wirings 31A and 31B. The connectors 32A and 32B are electrically connected to each of the pair of electrodes 12 and 13.

The operation of the electrostatic adsorption device ED is controlled by a controller (not shown), and the application of voltage in the voltage application unit PS is also controlled by this controller. When a voltage is applied to the contact member 11 via the pair of electrodes 12 and 13 of the suction pad AP by the voltage application unit PS, an electrostatic force is generated on the contact surface 11f of the contact member 11. By generating an electrostatic force while the contact surface 11f of the contact member 11 is in contact with the surface OBf of the cardboard container OB, the cardboard container OB can be attracted to the contact surface 11f of the contact member 11.

When the electrostatic suction device ED sucks the cardboard container OB by electrostatic force, the contact surface 11f of the contact member 11 is deformed following the surface OBf of the cardboard container OB. At this time, the concave portions 15a and the convex portions 15b forming the uneven portion 15 of the contact surface 11f are in a state of imitating the fine irregularities of the rough surface forming the surface OBf of the cardboard container OB, and are in a state of imitating the fine irregularities of the rough surface forming the surface OBf of the cardboard container OB. The contact area with the contact surface 11f increases. As a result, the suction force of the cardboard container OB on the surface OBf is increased, and the suction pad AP firmly sucks the cardboard container OB.

Next, a method of manufacturing the suction pad AP of the electrostatic suction device ED as described above will be described. FIG. 4 is a flowchart showing an example of a method for manufacturing the contact member 11. FIG. 5 is a cross-sectional view showing an example of a transfer type TD used in the method for manufacturing the contact member 11. FIG. 6 is a cross-sectional view showing a mold material 55 for forming a transfer type TD. FIG. 7 is a cross-sectional view showing a state in which the upper surface 55a of the mold material 55 is processed by shot blasting to form the transfer surface 51f of the transfer type TD. As shown in FIG. 4, the method for manufacturing the contact member 11 includes a transfer type manufacturing step S1 and a contact member forming step S2.

The transfer type manufacturing step S1 is a step of manufacturing a transfer type TD for forming the contact member 11 of the suction pad AP. As shown in FIG. 5, the transfer type TD includes a mold main body 51 made of, for example, a metal material such as iron, aluminum, and SUS, a glass plate, a resin plate, and the like, and an outer frame member 52. The mold body 51 has a plate shape having a predetermined thickness, and has a transfer surface 51f for forming the contact surface 11f of the contact member 11 on the upper surface thereof. The transfer surface 51f is formed with irregularities 53 for forming the concave portions 15a and the convex portions 15b forming the concave-convex portion 15 of the contact surface 11f by transfer.

The outer frame member 52 is provided on the mold body 51. The outer frame member 52 is provided on the outer peripheral side of the transfer surface 51f so as to project upward from the transfer surface 51f and surround the transfer surface 51f. The outer frame member 52 has a rectangular opening 52a inside the contact member 11 in a plan view, depending on the outer shape of the contact member 11. In the present embodiment, the outer frame member 52 is a rectangular frame-like body in a plan view. The thickness of the outer frame member 52 (height protruding upward from the transfer surface 51f) is the same as or substantially the same as the thickness of the contact member 11 to be formed. That is, the thickness of the contact member 11 to be formed is set by the thickness of the outer frame member 52.

As shown in FIG. 4, the transfer mold manufacturing step S1 includes a concavo-convex forming step S11 and an outer frame member mounting step S12. In the unevenness forming step S11, as shown in FIG. 6, the unevenness 53 is formed on the smooth upper surface 55a of the mold material 55, which is the material of the mold main body 51. As shown in FIG. 7, the unevenness 53 is processed by, for example, shot blasting. That is, a large number of granular materials (media) M are sprayed from the injection nozzle N together with a fluid such as air or water onto the upper surface 55a, and the granular materials M collide with the upper surface 55a. When a large number of granules M collide with the upper surface 55a at high speed, the smooth upper surface 55a of the mold material 55 is dented, the unevenness 53 is formed, and the mold body 51 is prepared.

As the granules used in the above-mentioned shot blasting, for example, stainless steel or iron granules can be adopted, and the particle size of the granules M is preferably 0.2 mm or more and 0.3 mm or less, for example. Further, the granular material M used is not limited to a spherical shape, and may be, for example, a columnar shape or the like. Further, the granular material M is not limited to having a certain shape, and different shapes may be mixed. As the granular material M, other than the above examples may be used depending on the material of the mold body 51, the surface roughness of the unevenness 53 (concave and convex portion 15 of the contact member 11) to be formed, and the like.

Further, the processing method for forming the unevenness 53 is not limited to using shot blasting. For example, the unevenness 53 may be formed by cutting the upper surface 55a of the mold material 55 with a processing tool such as a cutting tool.

In the outer frame member attaching step S12, the outer frame member 52 is attached to the mold body 51 as shown in FIG. In the outer frame member attaching step S12, for example, the outer frame member 52 formed in advance in a predetermined shape is fixed on the mold body 51 by various fixing means such as adhesion, welding, or bolting. As described above, since the thickness of the contact member 11 is defined by the thickness of the outer frame member 52, the thickness of the outer frame member 52 is strictly controlled. The transfer type TD is prepared through the outer frame member attaching step S12. In this embodiment, the embodiment in which the outer frame member 52 is used is described as an example, but the embodiment in which the outer frame member 52 is not used may be used. For example, in the material supply step S21 described later, the thickness of the contact member 11 can be controlled by adjusting the rotation speed of the transfer type TD without using the outer frame member 52.

FIG. 8 is a cross-sectional view showing a state in which a liquid dielectric material (pad forming material, contact member forming material) is supplied on the transfer surface 51f of the transfer type TD. FIG. 9 is a cross-sectional view showing a state in which the contact member 11 is created by solidifying the dielectric material on the transfer surface 51f. FIG. 10 is a cross-sectional view showing a state in which the contact member 11 is taken out from the transfer surface 51f of the transfer type TD. After manufacturing the transfer type TD, in the contact member forming step S2, the contact member 11 is produced using the transfer type TD. As shown in FIG. 4, the contact member forming step S2 includes a material supply step S21, a material solidification step S22, and a contact member take-out step S23.

In the material supply step S21, as shown in FIG. 8, the liquid dielectric material DM is supplied onto the transfer surface 51f of the transfer type TD. The dielectric material DM is supplied onto the inner transfer surface 51f from the opening 52a of the outer frame member 52. The dielectric material DM is supplied in an amount equal to or higher than the upper end of the outer frame member 52. In the material supply step S21, for example, the spin coater method may be used. The dielectric material DM is supplied on the transfer surface 51f by the dispenser D. In the spin coater method, the transfer type TD rotates around the central axis C, and the supplied dielectric material DM spreads on the transfer surface 51f by centrifugal force. By using the spin coater method, the dielectric material DM spreads uniformly on the transfer surface 51f. In the material supply step S21, another method / apparatus such as a spray coater may be used instead of the spin coater method. By using these devices, the film thickness of the contact member 11 can be formed thinly and uniformly. In the electrostatic adsorption device ED, the thinner the distance from the electrodes 12 and 13 to the contact surface 11f (that is, the film thickness of the contact member 11), the better the electrostatic adsorption force.

Further, in the material supply step S21, in order to prevent bubbles from remaining between the transfer surface 51f and the dielectric material DM, the transfer type TD may be vibrated, or microwaves or the like may be generated toward the dielectric material DM. May be irradiated. Further, in order to improve the wettability of the dielectric material DM on the transfer surface 51f, a parent liquid film may be coated on the transfer surface 51f.

The liquid dielectric material DM is supplied to the central portion of the transfer surface 51f. As the transfer type TD rotates around the central axis C, the liquid dielectric material DM spreads to the outer peripheral side on the transfer surface 51f. Further, the region where the liquid dielectric material DM spreads is defined by the outer frame member 52. Therefore, the target film thickness can be easily changed by changing the height of the outer frame member 52. Further, even if the excess dielectric material DM is supplied onto the transfer surface 51f, the excess over the upper end of the outer frame member 52 and overflows to the outside of the outer frame member 52, so that the contact member 11 having a desired thickness Is obtained.

In the material solidification step S22, the dielectric material DM supplied on the transfer surface 51f is solidified. In order to solidify the dielectric material DM, it may be left in the air for a predetermined time to be naturally dried, or may be heated or the like under temperature conditions corresponding to the dielectric material DM. Further, in the material solidification step S22, the transfer type TD may be housed in a chamber or the like set in a reduced pressure atmosphere and dried under reduced pressure. As shown in FIG. 9, by solidifying the dielectric material DM, a contact member 11 on which the unevenness 53 of the transfer surface 51f is transferred is created inside the outer frame member 52 on the transfer surface 51f.

In the contact member taking-out step S23, as shown in FIG. 10, the solidified contact member 11 is removed from the outer frame member 52 and the transfer surface 51f of the transfer type TD. The removed contact member 11 is formed with a contact surface 11f having an uneven portion 15 on which the uneven portion 53 of the transfer surface 51f is transferred. The next contact member 11 can be produced by supplying the liquid dielectric material DM again to the transfer type TD after the contact member 11 is taken out. That is, the transfer type TD can be reused.

In the pre-process or post-process of the contact member taking-out step S23, an electrode forming step of forming a pair of electrodes 12 and 13 on the boundary surface 11g of the contact member 11 is performed. In this electrode forming step, the electrodes 12 and 13 prepared in advance may be attached to the boundary surface 11g with an adhesive or the like to form a pair of electrodes 12 and 13, or the boundary surface 11g may be formed by using a conductive paste. A pair of electrodes 12 and 13 may be formed by creating a pattern of the electrodes 12 and 13 and heating the contact member 11 to a temperature at which the contact members 11 do not melt. Through this electrode forming step, the pad end portion AP1 is produced. Further, a further dielectric layer (pad base AP2) is formed on the pair of electrodes 12 and 13, and the electrodes are insulated from each other. The pad base AP2 is made of the same dielectric material DM as the contact member 11, and the method of making the pad base AP2 is arbitrary. Further, a pad base AP2 prepared in advance may be attached to the pad end AP1, or a liquid dielectric material DM may be supplied onto the pad end AP1 (on the pair of electrodes 12 and 13) to supply the pad. The base AP2 may be created. Through these steps, the suction pad AP is created. After that, as shown in FIG. 1, the electrostatic suction device ED is manufactured by attaching the suction pad AP to the pad holding member PH.

The applicant conducted an experiment / verification to evaluate the adsorption force of the electrostatic adsorption device ED as described above. The result will be described. First, a transfer type TD for forming the contact member 11 was manufactured. As the mold material 55 of the transfer type TD, a material made of SUS material having an outer diameter of 110 mm and a thickness of 2 mm was prepared.

Subsequently, the upper surface 55a of the mold material 55 was subjected to the following processing.
(Example 1)
An iron ball having a diameter of 0.2 mm was used as the granular material M, and the granular material M was injected onto the upper surface 55a of the mold material 55 at a pressure of 0.5 Mpa and processed by shot blasting.
(Example 2)
A hard steel wire (WC material) having an average particle diameter of 300 μm was used as the granular material M, and the granular material M was sprayed onto the upper surface 55a of the mold material 55 at a pressure of 0.5 Mpa and processed by shot blasting.

Further, for comparison, the upper surface 55a of the same mold material 55 was prepared with the following processing.
(Comparative Example 1)
The upper surface 55a of the mold material 55 was mirror-finished.
(Comparative Example 2)
A hairline finish was applied to the upper surface 55a of the mold material 55.
(Comparative Example 3)
Alumina having a count of # 60 was used as the granular material M, and the granular material M was injected onto the upper surface 55a of the mold material 55 at a pressure of 0.5 Mpa and processed by shot blasting.
(Comparative Example 4)
Alumina having a count of # 150 was used as the granular material M, and the granular material M was injected onto the upper surface 55a of the mold material 55 at a pressure of 0.5 Mpa and processed by shot blasting.
(Comparative Example 5)
A hard steel wire (WC material) having an average particle diameter of 500 μm was used as the granular material M, and the granular material M was sprayed onto the upper surface 55a of the mold material 55 at a pressure of 0.5 Mpa and processed by shot blasting.

An outer frame member 52 was attached to each of the mold bodies 51 obtained in Examples 1 and 2 and Comparative Examples 1 and 5. The outer frame member 52 used had a rectangular shape of 105 mm and a thickness (height) of 80 μm. In Examples 1 and 2 and Comparative Examples 1 to 5, transfer type TDs having each transfer surface 51f were prepared.

Next, the contact member 11 was prepared using the transfer type TDs of Examples 1 and 2 and Comparative Examples 1 and 5. First, silicone rubber is adopted as the dielectric material DM, liquid silicone rubber is supplied onto the transfer surface 51f by the spin coater method, the transfer type TD is pre-rotated, and then rotated at 1000 rpm for 30 seconds to transfer. The dielectric material DM was spread on the surface 51f to obtain a contact member 11 having a thickness corresponding to the thickness (height) of the outer frame member 52. Further, a pair of electrodes 12 and 13 were provided on the boundary surface 11g of the obtained contact member 11. The pair of electrodes 12 and 13 adopted the same comb-tooth shape in Examples 1 and 2 and Comparative Examples 1 to 5. Then, the pad base AP2 was made of silicone rubber on the pair of electrodes 12 and 13. The suction pad AP manufactured as described above was attached to the pad holding member PH.

(Surface roughness of contact surface)
With respect to the contact surface 11f of the suction pad APs of Examples 1 and 2 and Comparative Examples 1 to 5 thus obtained, the arithmetic average roughness Ra of the surface roughness, the maximum height roughness Rz of the surface roughness, and the surface The average length AR of the roughness motif in the roughness motif parameter was obtained. For reference, also for the surface OBf of the cardboard container OB, the arithmetic average roughness Ra of the surface roughness, the maximum height roughness Rz of the surface roughness, and the average length of the roughness motif in the motif parameters of the surface roughness I asked for each AR. The results are shown in Table 1.

(Evaluation of shear friction force)
After that, the contact surface 11f of the suction pad AP was brought into contact with the upper surface of the cardboard container OB placed on the floor surface. The cardboard container OB used had a length of 385 mm, a width of 220 mm, a height of 180 mm, and a weight of 25 kg. In this state, a voltage of 6 kV was applied to the pair of electrodes 12 and 13 to electrostatically adsorb the cardboard container OB. After 15 seconds have passed since the electrostatic adsorption, the electrostatic adsorption device ED is moved in the horizontal direction at a speed of 40 mm / sec, and the shear friction force generated between the adsorption pad AP and the cardboard container OB at that time is generated. Was measured with a push-pull gauge. The results are shown in Table 1.

As shown in Table 1, in Examples 1 and 2, the surface roughness (arithmetic mean roughness Ra, maximum height roughness Rz) of the uneven portion 15 is smaller than the surface OBf of the cardboard container OB. Further, in Examples 1 and 2, the maximum height roughness Rz of the surface roughness was 0.1 μm or more and 7.0 μm or less due to the uneven portion 15 formed on the contact surface 11f. Further, in Examples 1 and 2, the average length AR of the roughness motif in the motif parameter of the surface roughness of the uneven portion 15 was 90 or less. Further, in Examples 1 and 2, the average value of the height difference between the concave portion 15a and the convex portion 15b of the concave-convex portion 15 was smaller than the surface OBf of the cardboard container OB.

Further, as shown in Table 1, it was confirmed that in Examples 1 and 2, the shear frictional force was larger than that in Comparative Examples 1 to 5. Further, as shown in Table 1, in Comparative Examples 3 and 4 in which the shear frictional force was less than 1.0, the value of the maximum height roughness Rz exceeded 7.0. In Comparative Example 5, which has the next lowest shear frictional force, the value of the maximum height roughness Rz is not so different from that of Examples 1 and 2, but the value of the average length AR of the roughness motif in the motif parameter is 99.346. Higher than other examples. In Examples 1 and 2 and Comparative Examples 1 and 2 in which the shear friction force shows a high value of 2.88 to 3.57, the value of the average length AR of the roughness motif in the motif parameter is 90 or less, and The value of the maximum height roughness Rz is 0.1 or more and 7.0 or less. That is, if the average length AR of the roughness motif in the motif parameter has a value of 90 or less and the maximum height roughness Rz has a value of 0.1 or more and 7.0 or less, the shear frictional force is increased. It was confirmed that it is preferable (to increase the contact area of the cardboard container OB with respect to the surface OBf). Further, in Examples 1 and 2 and Comparative Example 2 in which the shear frictional force exceeds 3.0, the value of the maximum height roughness Rz is 1.0 or more and 5.0 or less. That is, it was confirmed that when the value of the maximum height roughness Rz is 1.0 or more and 5.0 or less, it is preferable to further increase the shear frictional force. Further, in Comparative Examples 1 and 2, a decrease in shear frictional force (adsorption force) due to adhesion of dirt on the surface OBf of the cardboard container OB was observed. In particular, in Comparative Example 2, it was confirmed that the shear frictional force was significantly reduced due to the adhesion of dirt. It was confirmed that there was no or small decrease in the shear friction force due to the adhesion of dirt in Examples 1 and 2 as opposed to Comparative Examples 1 and 2. In Examples 1 and 2, the value of the maximum height roughness Rz is 4.0 or more and 5.0 or less. That is, when the value of the maximum height roughness Rz is 4.0 or more and 5.0 or less, in order to avoid a decrease in shear friction force (adsorption force) even if dirt adheres to the surface OBf of the cardboard container OB. It was confirmed that it was preferable.

Further, the contact between the adsorption pad AP formed of the transfer type TD having the transfer surface 51f of Example 1 and the adsorption pad AP formed of the transfer type TD having the transfer surface 51f of Comparative Examples 2 and 3 is brought into contact with each other. The surface 11f was observed with a microscope. The observed images are shown in FIGS. 11 to 13. FIG. 11 is an observation image of the contact surface 11f in the suction pad AP of the first embodiment. FIG. 12 is an observation image of the contact surface 11f in the suction pad AP of Comparative Example 2. FIG. 13 is an observation image of the contact surface 11f of the suction pad AP of Comparative Example 3.

As shown in FIG. 11, fine irregularities are irregularly formed on the contact surface 11f in the suction pad AP of the first embodiment. On the other hand, as shown in FIGS. 12 and 13, the uneven portion 15 as in the first embodiment is not formed on the contact surface 11f of the suction pad AP of Comparative Examples 1 and 2. Further, the uneven portion 15 of the contact surface 11f of the suction pad AP of Comparative Example 3 (the same applies to Comparative Examples 4 and 5) has a higher density of unevenness than that of Examples 1 and 2, and the concave and convex portions have a higher density. It was confirmed that the difference in height was also large.

(Comparative verification of electrode patterns)
Further, since the patterns of the pair of electrodes 12 and 13 have been examined, the results will be described. The following patterns were prepared as the patterns of the pair of electrodes 12 and 13.
(Example 11)
A pair of comb-shaped electrodes 12 and 13 having three electrode portions 12b and 13b having an electrode width of 10 mm and an electrode length of 45 mm were formed with a gap of 1 mm.
(Example 12)
Electrodes having an electrode width of 33 mm were formed with a gap of 1 mm.
(Example 13)
A pair of comb-shaped electrodes 12 and 13 having six electrode portions 12b and 13b having an electrode width of 5 mm and an electrode length of 62 mm were formed with a gap of 1 mm.
(Example 14)
A pair of comb-shaped electrodes 12 and 13 having six electrode portions 12b and 13b having an electrode width of 5.5 mm and an electrode length of 62 mm were formed with a gap of 0.5 mm.
For each of the electrodes 12 and 13 of Examples 11 to 14, the number of pairs of electrode portions 12b and 13b, the length of the gap d between the pair of electrodes 12 and 13, (path length), and the area of the pair of electrodes 12 and 13. Is shown in Table 2.

For each of the electrodes 12 and 13 of Examples 11 to 14, the electrostatic adsorption force FN and the pressure PN per unit area were calculated by the following equations (1) and (2). In the formulas (1) and (2), W is the electrode width, L is the electrode length, d is the electrode gap, V is the applied voltage, ε0 is the vacuum permittivity, and εr is the relative permittivity.

As a result, it was obtained that the electrostatic adsorption force increased in the order of Examples 11 to 14. Comparing the calculation results with Table 1, the larger the number of pairs (number of pairs) of the electrode portions 12b and 13b, the larger the electrode area, and the narrower the gap d between the electrodes 12 and 13, the more static per unit area. It can be said that the power tends to be high.

Subsequently, each of the electrodes 12 and 13 of Examples 11 to 14 was formed on the contact member 11 of Example 1 described above, and the shear frictional force when the cardboard container OB was adsorbed was evaluated. The result is shown in FIG. As shown in FIG. 14, as compared with the case where the electrodes 12 and 13 of Examples 11 and 12 are provided, when the electrodes 12 and 13 having the patterns of Examples 13 and 14 are provided, the shear per unit area is provided. It was confirmed that the frictional force was significantly improved.

Although the embodiments and examples of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments and examples. It will be apparent to those skilled in the art that various changes or improvements can be made to the above-described embodiments and examples. In addition, the technical scope of the present invention also includes a form in which such a modification or improvement is added. In addition, one or more of the requirements described in the above-described embodiments and examples may be omitted. In addition, the requirements described in the above-described embodiments and the like can be combined as appropriate. Further, the execution order of each step shown in the present embodiment can be realized in any order as long as the result of the previous step is not used in the subsequent step. Further, even if the operations in the above-described embodiment are described using "first", "next", "continued", etc. for convenience, it is not essential to carry out the operations in this order.

AP1 ・ ・ ・ Pad end AP2 ・ ・ ・ Pad base Cap ・ ・ ・ Central part OB ・ ・ ・ Cardboard container (object)
OBf ... Surface DM ... Contact member material ED ... Electrostatic adsorption device M ... Granular material PH ... Pad holding member TD ... Transfer type 11 ... Contact member 11f ... Contact Surfaces 12, 13 ... Electrodes 15 ... Concavo-convex portion 15a ... Concave 15b ... Convex portion 51f ... Transfer surface 52 ... Outer frame member 53 ... Concavo-convex

Claims (12)

A contact member made of a dielectric having a contact surface that can be deformed according to the surface of an object,
A pair of electrodes capable of applying a voltage to the contact member are provided.
The contact surface is an electrostatic adsorption device having a concave-convex portion in which a concave portion and a convex portion are continuous in both an arbitrary direction along the surface and both intersecting directions in the one direction and in the intersecting direction along the surface. The electrostatic adsorption device according to claim 1, wherein the pair of electrodes are provided in contact with the contact member and can be deformed together with the contact member. The electrostatic adsorption device according to claim 1 or 2, wherein the surface roughness of the contact surface due to the uneven portion is smaller than the surface roughness of the surface of the object. The electrostatic adsorption device according to any one of claims 1 to 3, wherein the contact surface has a maximum height roughness Rz of surface roughness due to the uneven portion of 0.1 μm or more and 7.0 μm or less. .. The electrostatic adsorption device according to any one of claims 1 to 4, wherein the contact surface has an average length AR of a roughness motif of 90 or less in the motif parameter of the surface roughness due to the uneven portion. The contact surface has any one of claims 1 to 5, wherein the average value of the height difference between the concave portion and the convex portion in the uneven portion is smaller than the average value on the surface of the object. The electrostatic adsorption device according to. The static electricity according to any one of claims 1 to 6, wherein the shear frictional force generated between the object and the contact surface in a state where the surface of the object is adsorbed is 3.0 mN / mm ^{2 or more.} Electric adsorption device. The electrostatic adsorption according to any one of claims 1 to 7, wherein the contact surface is formed by being transferred by using a transfer mold having a transfer surface formed by surface processing by shot blasting. apparatus. A method of manufacturing a contact member provided in an electrostatic adsorption device that adsorbs an object and having a contact surface that can be deformed according to the surface of the object.
Forming irregularities on the transfer surface of the transfer type and
A liquid dielectric material for forming the contact member is supplied onto the transfer surface to be solidified.
A method for manufacturing a contact member, which comprises removing the contact member from the transfer surface. The method for manufacturing a contact member according to claim 9, further comprising forming the unevenness on the transfer surface by colliding the particles with the transfer surface of the transfer type. The method for producing a contact member according to claim 10, wherein the granular material is made of SUS or iron and has a particle size of 0.2 mm to 0.3 mm. The transfer type has an outer frame member that projects upward from the transfer surface and surrounds the transfer surface on the outer peripheral side of the transfer surface.
The method for manufacturing a contact member according to any one of claims 9 to 11, which comprises supplying the liquid dielectric material to the inside of the outer frame member.

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