The present invention relates to conveyance equipment.
In recent years, equipment for conveying a plate-like member such as a semiconductor wafer or a glass substrate in a non-contacting manner has been developed. For example, in Patent Document 1, equipment is proposed for conveying a plate-like member in a non-contacting manner, by applying Bernoulli's principle. The equipment includes a cylindrical chamber that opens on the underside of the equipment, into which fluid is supplied to generate a swirl flow. The swirl flow generates a negative pressure in the center, which exerts suction on the plate-like member. On the other hand, a fluid flowing out of the cylindrical chamber causes a given distance to be maintained between the equipment and the plate-like member. Consequently, the equipment conveys the plate-like member in a non-contacting manner. Also in Patent Document 1, use of liquid as fluid is proposed.
Patent Document 1: JP 2005-51260 A1
It is an object of the present invention to prevent a plate-like member being conveyed by conveyance equipment, which holds the plate-like member by discharging liquid to generate a negative pressure between the conveyance equipment and the plate-like member, from falling off the conveyance equipment under the weight of liquid accumulating on the plate-like member.
The present invention provides conveyance equipment for conveying a plate-like member, comprising: a plate-like base body; and plural items of liquid discharging equipment provided at the base body, that hold the member by discharging liquid to generate a negative pressure between the liquid discharging equipment and the member, wherein each of the plural items of liquid discharging equipment comprises: a columnar main body; a flat end face formed at the main body, that faces the member; a concave part formed at the end face; one or more liquid passages that discharge liquid into the concave part at a peripheral edge of the concave part, wherein: the one or more liquid passages are arranged so that a direction in which a liquid flows out of the concave part along the end face and a direction from a center of gravity of the member toward a position of the member, opposite the liquid discharging equipment form an angle smaller than or equal to 90 degrees; each of the plural items of liquid discharging equipment comprises only one or more liquid passages as a structure for discharging liquid into the concave part at a peripheral edge of the concave part; and the conveyance equipment comprises only the plural items of liquid discharging equipment as a structure for generating a negative pressure between the conveyance equipment and the member.
In the conveyance equipment, two or more items of liquid discharging equipment may be arranged at the base body on a circumference of a circle, and one or more item of liquid discharging equipment may be arranged at the base body at a central part of the circle.
The present invention prevents a plate-like member being conveyed by conveyance equipment, which holds the plate-like member by discharging liquid to generate a negative pressure between the conveyance equipment and the plate-like member, from falling off the conveyance equipment under the weight of liquid accumulating on the plate-like member
An embodiment of the present invention will be described below with reference to the drawings.
Base body 1 has a disk shape. Base body 1 is made of, for example, an aluminum alloy. Each of twelve swirl flow-forming bodies 2 has a column shape, which is provided at a face of base body 1. The face of base body 1 is, specifically, a face opposite to plate-like member W being conveyed. The face of base body 1 will hereinafter be referred to as “bottom face.” Twelve swirl flow-forming bodies 2 are arranged at the bottom face on the circumference of a circle. Twelve swirl flow-forming bodies 2 are arranged at equal intervals along the outer circumference of base body 1. Each of swirl flow-forming bodies 2 is equipment for holding plate-like member W by discharging liquid such as pure water or carbonated water to generate a negative pressure between the swirl flow-forming body and the plate-like member. Each of swirl flow-forming bodies 2 is made of, for example, an aluminum alloy. Each of swirl flow-forming bodies 2 is an example of “liquid discharging equipment” according to the present invention. Conveyance equipment 10 includes only twelve swirl flow-forming bodies 2 as a mechanism for generating a negative pressure between the conveyance equipment and plate-like member W.
Each of twelve friction members 3 has a column shape, which is provided at the bottom face of base body 1. Twelve friction members 3 are arranged at the bottom face at equal intervals on the circumference of the circle, on which swirl flow-forming bodies 2 are arranged. Each of friction members 3 is arranged between two swirl flow-forming bodies 2. Each of friction members 3 is a member for generating a friction force between the friction member and a surface of plate-like member W being conveyed, by coming into contact with the surface of the plate-like member, which friction force prevents the plate-like member from moving Each of friction members 3 is made of, for example, a fluorine-contained rubber. Six hole parts 4 are through-holes having an elongated shape with rounded ends, which are provided at base body 1. Six hole parts 4 are arranged at base body 1 at equal intervals on the circumference of a circle. The circle on whose circumference hole parts 4 are arranged and the circle on whose circumference swirl flow-forming bodies 2 are arranged are concentric. Hole parts 4 are arranged nearer the center of a surface of base body 1 in relation to swirl flow-forming bodies 2.
Communication passage 28 is provided inside main body 21, and linearly extends in a radial direction of the bottom or upper face of main body 21. Both ends of communication passage 28 communicate with annular passage 27. Communication passage 28 supplies liquid supplied into main body 21 via introduction port 26, to annular passage 27. Introduction passages 29 discharge liquid into concave part 22 via jetting port 24 at the peripheral edge of the concave part. Specifically, introduction passages 29 are formed substantially in parallel with end face 23. Introduction passages 29 are also formed so that they extend in a direction tangential to the outer circumference of concave part 22. One end of introduction passage 29 communicates with annular passage 27, and the other end communicates with jetting port 24. Introduction passages 29 are an example of a “liquid passage” according to the present invention. Swirl flow-forming body 2 includes only introduction passages 29 as a mechanism for discharging liquid into concave part 22 at the peripheral edge of concave part 22.
When liquid is supplied to swirl flow-forming body 2 described in the foregoing via introduction port 26, the liquid passes through communication passage 28, annular passage 27, and introduction passage 29 to be discharged into concave part 22 via jetting port 24. The fluid discharged into concave part 22 forms a swirl flow and is straightened in the concave part, and thereafter flows out from the opening of the concave part. In that situation, if plate-like member W is positioned opposite end face 23, flow of outside fluid (for example, air or water) into concave part 22 is restricted. In addition, since a centrifugal force of the swirl flow develops, and entrainment occurs, fluid molecules per unit volume in the center of the swirl flow become less dense; namely, a negative pressure is generated. As a result, plate-like member W is pushed toward end face 23 by surrounding fluid. On the other hand, as plate-like member W comes close to end face 23, an amount of liquid flowing out of concave part 22 decreases, and a velocity of a liquid discharged into concave part 22 through jetting port 24 decreases, so that a pressure in the center of the swirl flow increases. Accordingly, plate-like member W does not come into contact with end face 23, and a given distance is maintained between the plate-like member and the end face.
As shown in
Since liquid discharged from swirl flow-forming body 2 flows toward the outer edge of plate-like member W, the liquid is easily discharged from the outer edge of the plate-like member. Also, since a flow of liquid toward the outer edge of plate-like member W is formed, liquid discharged to the central part of the plate-like member is easily discharged from the outer edge of the plate-like member. Consequently, liquid is prevented from accumulating on plate-like member W. According to conveyance equipment 10, plate-like member W is prevented from falling off the conveyance equipment under the weight of liquid accumulating on the plate-like member.
It is to be noted that a direction in which a liquid flows out of concave part 22 along end face 23 depends on the diameter and depth of concave part 22, and a velocity of the fluid. In the example shown in
The above embodiment may be modified as described below. Two or more of the following modifications may be combined with each other.
Conveyance equipment 10 according to the above embodiment may have another shape.
Base body 5 is a plate-like member in the shape of a two-pronged fork, which includes rectangular holding part 54 and two arm parts 55 that extend forkedly from holding part 54. Base body 5 is made of, for example, an aluminum alloy. Ten swirl flow-forming bodies 2 are provided at a face of two arm parts 55 constituting base body 5. The face of arm parts 55 is, specifically, a face opposite to plate-like member W being conveyed. The face of arm parts 55 will hereinafter be referred to as “bottom face.” Ten swirl flow-forming bodies 2 are arranged at two arm parts 55 on the circumference of a circle. Five swirl flow-forming bodies 2 are arranged at each of arm parts 55 at equal intervals.
Twelve friction members 3A are each a plate-like member, which are provided at the bottom face of two arm parts 55. Twelve friction members 3A are arranged at the bottom face on the circumference of the circle, on which swirl flow-forming bodies 2 are arranged. Friction members 3A are arranged at each of arm parts 55 so that two friction members 3A sandwich one swirl flow-forming body 2. Each of friction members 3A is a member for generating a friction force between the friction member and a surface of plate-like member W being conveyed, by coming into contact with the surface of the plate-like member, which friction force prevents the plate-like member from moving. Each of friction members 3 is made of, for example, a fluorine-contained rubber.
In conveyance equipment 20, introduction passage 29 of swirl flow-forming body 2 is arranged so that a direction in which a liquid flows out of concave part 22 along end face 23 and a direction from the center of gravity of plate-like member W toward a position of the plate-like member, opposite the swirl flow-forming body form an angle of substantially 45 degrees. The angle is the smaller of the two angles formed by the two directions.
Conveyance equipment 10 according to the above embodiment may be provided with equipment for facilitating discharge of liquid discharged from swirl flow-forming bodies 2 from the outer edge of plate-like member W.
Radial flow-forming body 6 is provided at the bottom face of base body 1. Radial flow-forming body 6 is provided at the central part of the circle, on which twelve swirl flow-forming bodies 2 are arranged. Radial flow-forming body 6 is equipment for holding plate-like member W by discharging liquid to generate a negative pressure between the radial flow-forming body and the plate-like member. Radial flow-forming body 6 is also equipment for preventing liquid from accumulating on the center of plate-like member W by radially discharging liquid at the center of the bottom face of base body 1. Liquid is supplied to radial flow-forming body 6 via communication passage 12, as shown in
Communication passage 70 is provided inside main body 61, which linearly extends in a radial direction of annular passage 69. The central part in an axial direction of communication passage 70 communicates with introduction passage 68, and both ends communicate with annular passage 69. Communication passage 70 supplies liquid supplied from introduction passage 68, to annular passage 69. Annular passage 69 has a cylindrical shape, which is provided inside main body 61. Annular passage 69 is formed so that the annular passage and main body 61 are coaxial. Annular passage 69 supplies liquid supplied from communication passage 70, to nozzle holes 66.
Each of six nozzle holes 66 discharges liquid into annular concave part 62 at the peripheral edge of the annular concave part. Specifically, nozzle holes 66 are formed substantially in parallel with end face 63 or opposed face 64. Nozzle holes 66 are also formed so that they linearly extend in a radial direction of the bottom or upper face of main body 61. One end of nozzle hole 66 communicates with annular passage 69, and the other end communicates with annular concave part 62. Six nozzle holes 66 are formed on the same plane so that adjacent nozzle holes 66 form an angle of substantially 45 degrees. Each of nozzle holes 66 is an example of a “liquid passage” according to the present invention.
When liquid is supplied to radial flow-forming body 6 described in the foregoing, via introduction port 67, the liquid passes through introduction passage 68, communication passage 70, and annular passage 69 to be discharged into annular concave part 62 via nozzle hole 66. The fluid discharged into annular concave part 62 flows out of the opening of the annular concave part. In that situation, if plate-like member W is positioned opposite opposed face 64, flow of outside fluid (for example, air or water) into the space between the opposed face and the plate-like member is restricted. In addition, since entrainment is generated by radial flows, fluid molecules per unit volume in the space become less dense; namely, a negative pressure is generated. As a result, plate-like member W is pushed toward end face 63 by surrounding fluid. On the other hand, as plate-like member W comes close to end face 63, an amount of liquid flowing out of annular concave part 62 decreases, and a velocity of a liquid discharged into through jetting port 24 decreases, so that a pressure in the space increases. Accordingly, plate-like member W does not come into contact with end face 63, and a given distance is maintained between the plate-like member and the end face.
Conveyance equipment 10A described in the foregoing functions further to prevent liquid from accumulating on plate-like member W, by including radial flow-forming body 6 arranged at the center of the bottom face of base body 1, which radially discharges liquid.
It is to be noted that the number (especially, the number of nozzle holes 66), configuration (especially, the configuration of the liquid passages in main body 61), and position of radial flow-forming bodies 6 are not limited to the example shown in the present modification. The parameters may be determined based on the size, shape, and material of plate-like member W to be conveyed by conveyance equipment 10A. Alternatively, swirl flow-forming body 2 may be arranged at the center of the bottom face of base body 1, instead of radial flow-forming body 6. Alternatively, a known non-contacting chuck including an electric fan (see, for example, JP 2011-138948 A1) may be provided. Alternatively, a known swirl flow-forming body including coupled concave parts (see, for example, JP 2007-324382 A1) may be provided. Alternatively, in a case where plate-like member W has a small diameter, base body 1 of conveyance equipment 10 may be provided with only radial flow-forming body 6 or the swirl flow-forming body including coupled concave parts, without having swirl flow-forming bodies 2.
In the above embodiment, swirl flow-forming body 2 may have another shape.
It is to be noted that the upper face of projecting part 30 and end face 23 may be on the same plane. The upper face of projecting part 30 may have a chamfered edge.
The configuration (especially, the configuration of liquid passages in base body 1) of base body 1 of conveyance equipment 10 is not limited to the example shown in the above embodiment. The number, shape, and position of friction members 3 and hole parts 4, which are provided at base body 1 of conveyance equipment 10, are not limited to the example shown in the above embodiment. The parameters may be determined based on the size, shape, and material of plate-like member W to be conveyed by conveyance equipment 10. Friction members 3 or hole parts 4 may be omitted from base body 1 of conveyance equipment 10. In a case where friction members 3 are omitted from base body 1 of conveyance equipment 10, plate-like member W conveyed by the conveyance equipment is caused to rotate by flows of liquid discharged from swirl flow-forming bodies 2. A resultant centrifugal force of plate-like member W facilitates discharge of liquid on the plate-like member from the outer edge of the plate-like member. In the case where friction members 3 are omitted from base body 1 of conveyance equipment 10, the base body may be provided with a known centering guide (see, for example, JP 2005-51260 A1) for positioning plate-like member W. Alternatively, in the above embodiment, the bottom face of base body 1 of conveyance equipment 10 may be provided with equipment for sucking liquid accumulating on plate-like member W. The equipment may be arranged, for example, at the central part of the circle, on which twelve swirl flow-forming bodies 2 are arranged.
The number, configuration, and position of swirl flow-forming bodies 2 provided at base body 1 of conveyance equipment 10 are not limited to the example shown in the above embodiment. The parameters may be determined based on the size, shape, and material of plate-like member W to be conveyed by conveyance equipment 10. For example, the number of swirl flow-forming bodies 2 may be smaller or greater than 12. Two or more lines of swirl flow-forming bodies 2 may be arranged along the outer circumference of base body 1. Swirl flows formed in swirl flow-forming bodies 2 may rotate in different directions. Main body 21 of swirl flow-forming body 2 may have a rectangular column shape or an elliptic column shape, instead of a circular column shape. Main body 21 of swirl flow-forming body 2 may be provided with a passage for directly connecting introduction port 26 to introduction passage 29, instead of annular passage 27 and communication passage 28. Slope 25 may be omitted from Main body 21 of swirl flow-forming body 2. In other words, the edge of end face 23 may not be chamfered. One or more of swirl flow-forming bodies 2 may discharge gas such as air.
A direction in which a liquid flows out of concave part 22 of swirl flow-forming body 2 along end face 23 and a direction from the center of gravity of plate-like member W toward a position of the plate-like member, opposite the swirl flow-forming body may form an angle other than substantially 45 degrees. The angle may be equal to or smaller than 90 degrees. Similarly, a direction in which a liquid flows out of concave part 22 of swirl flow-forming body 2 along end face 23 and a direction from the central part of the circle, on the circumference of which twelve swirl flow-forming bodies 2 are arranged, toward the swirl flow-forming body including introduction passage 29 may form an angle other than substantially 45 degrees. The angle may be equal to or smaller than 90 degrees. The number of introduction passages 29 provided at swirl flow-forming body 2 is not limited to one. The number may be two or more.
In the example shown in the drawing, a direction in which a liquid flows out of concave part 22 of swirl flow-forming body 2 along end face 23 and a direction from the center of gravity of plate-like member W toward a position of the plate-like member, opposite the swirl flow-forming body form an angle smaller than or equal to 90 degrees. In a case where two or more introduction passages 29 are provided, one or more introduction passages 29 may discharge gas such as air.
In the above embodiment, the bottom face of conveyance equipment 10 may be provided with radial flow-forming bodies 6 described in Modification 2 or known non-contacting chucks including an electric fan (see, for example, JP 2011-138948 A1), instead of swirl flow-forming bodies 2.
Number | Date | Country | Kind |
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2013-250224 | Dec 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2014/081377 | 11/27/2014 | WO | 00 |