JP5042864B2 - Airflow transfer device - Google Patents

Description

  The present invention relates to an air current conveying apparatus using a nozzle plate including an injection hole for levitating a plate-like object with gas injected from a plurality of inclined injection holes.

  2. Description of the Related Art Conventionally, an air current conveying device (air current levitating device) that floats a plate-like object such as a wafer by gas ejection and conveys it in a predetermined direction while keeping it in a non-contact state is disclosed in, for example, Patent Document 1 and Patent Document 2 As shown in FIG. 4, the ejection holes (hereinafter referred to as “vertical ejection holes”) that eject gas in a direction orthogonal to the conveying surface of the apparatus. It has the same meaning as the injection hole, and vice versa, or an injection hole for injecting gas in a direction not perpendicular to the conveying surface (hereinafter referred to as “inclined injection hole”). In addition, those provided with both of these jet holes are known. The gas ejected from these ejection holes is preferably at a high pressure in order to float the plate-like object.

  The glass substrate as an example of the plate-like material is, for example, a large substrate having a side of about 1 to 2 m and a thickness of less than 1 mm, and has a weight of about several kilograms. This is, for example, a size that has been studied as a liquid crystal substrate. In order to float such a large and thin substrate with an air current, a high-pressure air current or a large amount of air current is required. On the other hand, when such an air flow is used, the central portion of the substrate tends to swell upward. At this time, if the left and right force is applied from the airflow flowing along the bottom surface of the board, and the left and right forces are not balanced, the board may move laterally or change its orientation, making the posture unstable. (For example, Patent Document 3).

  Further, Patent Document 4 discloses a jet port opened by drilling, but a hole is drilled obliquely with respect to the conveyance surface of the processing plate of the transfer unit larger than the glass plate (conveyed object). It is made open. The movement of the glass plate and the stop of the glass plate are controlled by levitation of the glass plate by the ejection of gas from the ejection port. However, since a hole is drilled obliquely, it is difficult to completely prevent the drill tip from escaping, and the dimensional accuracy and productivity in the vicinity of the hole outlet are not sufficient. In addition, since the transfer unit based on the combination of parts improved by Patent Document 4 uses a plurality of parts, the cost tends to increase. Moreover, even if the gas is ejected toward the center of a wide conveyance surface that is almost the same size as the glass plate, it is difficult to expect improvement in levitation force due to the interaction of gas ejection from each ejection port. Furthermore, since the gas ejection from the ejection port in the transfer direction is also combined, it is difficult to say that all of the gas ejected is used to effectively lift the plate-like object.

  Patent Document 5 discloses that air that has passed through a horizontally extending horizontal passage is ejected from a widened inclined ejection hole. The inclined ejection holes have a right triangle shape in cross-sectional view, and it is difficult to say that the directionality of the ejected gas is sufficiently controlled.

  With the structure of the ejection hole as described above, it is difficult to sufficiently lift the plate-like object with a low pressure or a small amount of airflow, while the posture of the plate-like object may become unstable with a high pressure or a large amount of airflow. There is. Furthermore, since the size of the object to be conveyed is equal to the size of the conveying surface, it is necessary to use a base having a larger conveying surface when conveying a large object to be conveyed, and the formation of the ejection holes is more Not only is this difficult, but the degree of freedom in designing the transport surface may be reduced. Moreover, even if gas is ejected toward the center of a large conveyance surface, the same floating effect as that obtained with a small conveyance surface is not always obtained.

  By the way, since a substrate (plate-like object) levitation device is not normally arranged between two continuous conveyance units, a special conveyance such as raising the substrate higher by the previous conveyance unit is necessary to convey the space between them. It is desirable to take measures (Patent Document 6). When transporting between these two transport units, the top of the substrate hangs down due to its own weight, making it difficult to get on the transport surface of the next transport unit, or the top of the substrate being caught by the next transport unit. This is because the substrate may be damaged.

On the other hand, compressed air is ejected from the porous body, the thin plate is supported in a non-contact manner, and the support for transportation is arranged to constitute a support portion made of a porous body that protrudes downward when viewed from the front of the thin plate in the transportation direction. An apparatus is disclosed (Patent Document 7). However, since the thin plate is supported by the static pressure of air because the porous body is used, not only is the air pressurization efficiency low, but the apparatus is expensive. Further, when the upper surface of the porous body is flat, it is necessary to adjust the air pressure between the porous bodies, and complicated control is required. In addition, no antistatic measures are taken, and countermeasures against adverse effects due to static electricity are not sufficient.
JP 7-228342 A JP-A-8-181182 JP-A-3-272155 JP 2000-72250 A JP-A-11-268830 JP-A-8-91623 JP 2004-244186 A

  In view of the above problems, the present invention provides an air levitation device that sufficiently floats a plate-like object with a low pressure or a small amount of air flow and stabilizes the posture thereof, and an air flow conveying device based on the air levitation device. . Further, the present invention provides an airflow levitation device and an airflow conveyance device that form a conveyance surface by arranging a plurality of nozzle plates, and can float (and convey) a large object to be conveyed using these. Furthermore, the present invention provides a levitation device that can easily change the air injection position according to the substrate size, and an airflow conveyance device and a conveyance method that apply the airflow levitation device.

  In the present invention, an airflow conveying device (and an airflow levitation device) that floats a plate-like object by gas ejected from a plurality of inclined injection holes and keeps the plate-like object in a non-contact state and floats the plate-like object. A base for forming and / or supporting a transport surface to be supported, comprising: a base having a plurality of openings on the transport surface side; and a nozzle plate laid airtightly in each of the plurality of openings. . The nozzle plate may be integrally formed so as to include a flat portion constituting the transport surface and a plurality of inclined injection holes for injecting a floating gas to the transport surface side around the flat portion. The pressurized gas flowing in from each of the plurality of openings is injected in a predetermined injection direction as a rising gas from the plurality of inclined injection holes.

  In addition, a nozzle plate used in the apparatus includes the plurality of inclined injection holes and a flat portion to which the plate-like object is adjacent, and each of the plurality of inclined injection holes has at least a sufficient direction of the injected gas. The plurality of inclined injection holes inject the gas in at least two directions so as to form an air reservoir at a predetermined position by the injected gas. It is provided with the gas flow inclined so that it may do. The predetermined position is preferably near the flat portion.

  More specifically, the following are provided.

(1) A nozzle plate in an airflow levitation device capable of levitating a plate-like object by gas injected from a plurality of inclined injection holes, wherein the nozzle plate is arranged on the side facing the plate-like object, A flat portion adjacent to the shape, and openings of the plurality of inclined injection holes around the flat portion, and each of the plurality of inclined injection holes is injected in at least two injection directions from the opening. It is possible to provide a nozzle plate characterized by having gas flow paths that are inclined at at least two different angles so that an air reservoir is formed at a predetermined position by the injected gas.

  Here, the gas may include air, nitrogen, and other gases, and the plate-like object may include a wafer, a substrate, and other thin plate-like objects to be conveyed. The non-contact state may include a state that does not become an obstacle when the plate-like object is levitated. For example, it may include a state in which a predetermined distance is maintained between the plate-like object and the conveying surface of the airflow levitation device, and may include a state in which a certain drag force is generated between the plate-like object and the conveying surface. Furthermore, even if there is a portion that contacts a part, it may include a state where there is no hindrance to the conveyance as a whole. Here, the conveyance surface may include a surface to which the plate-shaped object to be conveyed approaches (or approaches), particularly a surface closest to the conveyance surface. The flat portion may be included in the transport surface and may form a substantially flat surface. Moreover, although it is preferable that a flat part does not contain the protrusion which protrudes from the surface, it can contain the part recessed from the surface.

(2) It further includes a groove formed around the flat part, the openings of the plurality of inclined injection holes are formed in a first wall that defines the groove, and the gas flow path is injected It is possible to provide the nozzle plate according to (1) above, which has a length that can sufficiently control the injection direction of each gas.

  The gas flow path having a length sufficient to sufficiently control the direction of the injected gas may be a gas flow path through which the injected gas passes, and the injection direction of the gas injected by passing through the gas flow path And the speed is defined to some extent. That is, if the gas flow path is sufficiently long, the direction in which the gas travels is likely to be one direction, and the direction of the injected gas is likely to be grouped by its inertial force. On the other hand, if it is too short, the injected gas tends to diffuse when it exits the inclined injection hole, and if it is too long, the flow velocity of the gas passing through the gas flow path tends to decrease due to tube resistance. For example, the distance L from the inclined injection hole to the air reservoir at the predetermined position is preferably 1/10000 to 1/1, more preferably 1/1000 to 1/10, and still more preferably 1/500. To 1/50. However, these conditions can vary depending on various conditions such as the type of gas used, temperature, and atmospheric pressure. Further, the cross-sectional shape of the gas flow path is not particularly limited, but it is preferable that the circumferential length along the gas flow path wall is not so long with respect to the cross-sectional area, for example, a circular shape (that is, a circle) Tubular gas channels) are preferred.

  Further, the predetermined position where the air reservoir is formed may be determined in relation to the plate-like object to be conveyed. This air reservoir may be on the transport surface or in the vicinity of the flat portion. The air reservoir may be a space partitioned by a wall or the like, but may include a free space that is not partitioned by a wall or the like. This air reservoir may have a pressure greater than the ambient pressure, and the pressure of the air reservoir may contribute to the floating of the transported plate-like object. The first wall may be a member having a first surface, and the first wall has the first surface to define the groove.

(3) The plurality of inclined injection holes are formed to be inclined so as to be substantially perpendicular to the surface of the first wall, and the injection direction is virtually determined from the openings of the plurality of inclined injection holes. When extended, the nozzle plate according to the above (2) can be provided, wherein the nozzle plate does not directly contact the second wall that defines the groove portion facing the first wall.

  The groove part is formed in a shape recessed from the flat part, and can form a larger gap with the plate-like object to be conveyed. The shape of the groove is not particularly limited, but the cross-sectional shape may include various shapes such as an ellipse, a semicircle, a rectangle, a square, and a triangle. As described later, a triangular shape (that is, a V-shaped groove) is more preferable. More preferably, the depth of the groove is substantially uniform in the longitudinal direction of the groove. Moreover, it is preferable that the gas injected from the openings of the plurality of inclined injection holes does not collide with a mating wall (second wall) forming a groove before reaching the air reservoir. If it collides, the airflow may not reach the air reservoir, or the speed when it reaches may be slow, and the contribution of the dynamic pressure of the airflow is reduced. Similarly to the first wall, the second wall may be a member having a second surface. The second wall has a second surface, and the groove portion is formed in the same manner as the first wall. Stipulate.

(4) The flat portion has a rectangular shape in a top view, and the groove portion includes a V-shaped groove having a predetermined opening angle by the first wall and the second wall, and the first wall and the first wall (2) or (3), wherein the two walls face each other and extend around the flat portion, and the second wall is closer to the flat portion than the first wall. A nozzle plate can be provided.

  The flat portion is close to the plate-like object and applies a force to the plate-like object by the pressure of the gas in the air reservoir formed in the vicinity thereof, so that the plate-like object is urged away from the flat portion. To do. Extending around the flat portion may include being formed so as to surround the flat portion. For example, the groove portion may be provided along the circumference of the flat portion. At this time, it is not necessary to surround the entire circumference of the flat portion, and it may include partially surrounding the flat portion. For example, the groove part divided into two along the two opposing sides located so that the said flat part may be pinched | interposed can be provided. Furthermore, the shape of the groove (the shape surrounding the flat portion) is not particularly limited, and the groove can be provided in a circle or an ellipse surrounding the flat portion. Such groove portions may be continuous or discontinuous. Various shapes such as a rectangle, a square, and a triangle can be used in addition to a circle or an ellipse, but a rectangle is more preferable. When a rectangular (or square) shape is used, it is preferable that the groove is provided with at least one set of grooves along sides facing each other. In the case of a circle, an ellipse, or a triangular shape, a pair of opposing sides (two sides) or grooves at positions of three or more sides are combined and injected from an inclined injection hole provided in the groove. It is preferable to provide such a groove portion so that an air reservoir is efficiently formed on the flat portion by gas.

  The predetermined opening angle is preferably 60 ° to 120 °, more preferably 70 ° to 110 °, still more preferably 80 ° to 100 °, and most preferably about 90 °. It is preferable that the opening angle is equally V-shaped so as to be symmetric with respect to the vertical line.

(5) Further, any one of the above (1) to (4), further comprising an air passage communicating with the gas flow path of the plurality of inclined injection holes on the side opposite to the side facing the plate-like object. The nozzle plate described in 1 can be provided.

  The predetermined opening angle of the V-shaped groove is not particularly limited, but it is desirable that the air accumulation can be efficiently performed. For example, when the opening angle is 90 degrees or more, regardless of the position of the inclined injection hole, it is provided on one surface (first wall) of the V-shaped groove substantially perpendicular to the surface. Most of the gas injected from the inclined injection hole exits the previous V-shaped groove toward the flat portion without changing the direction without colliding with the other surface (second wall) of the V-shaped groove. It is possible. Such a V-shaped groove can have a concave shape substantially perpendicular to the flat surface so that the V-shaped cross-section is symmetrical. On the other hand, the V-shape can be provided at a predetermined angle, but it is more preferable that the V-shape is provided without being inclined.

  More preferably, two or more inclined injection holes are provided in one V-shaped groove. Further, it is more preferable that the inclined injection holes are provided so that the positions in the height direction of the first surface are substantially aligned.

  More preferably, the air passage is provided one by one in one V-shaped groove. However, one air passage may be provided for two or more V-shaped grooves. Two or more air passages may be provided for one V-shaped groove.

(6) The nozzle plate has a rectangular plate shape having a predetermined thickness, and a side portion facing the plate-like object is chamfered with a predetermined size ( The nozzle plate according to any one of 1) to (5) can be provided.

  The chamfering can prevent the conveyed plate-like object from being caught at the corner of the side that defines the nozzle plate when it collides with the nozzle plate. Such chamfering can be performed, for example, at approximately 45 degrees with a thickness of about ½ of the thickness. It can also be rounded. These conditions are appropriately selected.

(7) Provided with at least one bolt hole having a counterbore that is recessed by the flat part, the bolt hole being formed on the side facing the plate-like object, the counterbore surface of the counterbore, and the plate-like The nozzle plate is formed so as to penetrate between the opposing surface formed on the opposite side of the object-facing side, and the nozzle plate is caused to contact the holding member by a fastening member that penetrates the bolt hole. And the nozzle plate according to any one of (1) to (6), wherein the nozzle plate is fixed to the holding member.

(8) The nozzle plate includes an outer peripheral wall extending along a peripheral edge defining the outer shape of the nozzle plate on the side opposite to the side facing the plate-like object, and the top of the outer peripheral wall is formed on the nozzle plate. An opposite side surface is defined, and the opposing surface protrudes from the opposite side surface defined by a top portion of the outer peripheral wall. The nozzle plate according to (7) can be provided.

(9) The nozzle plate according to any one of (1) to (8) above, wherein at least the flat portion is made of a resin having low chargeability.

Here, the resin having low chargeability preferably has a surface specific resistance of, for example, 10 ¹³ Ω or less at 23 ° C., more preferably 10 ¹² Ω or less. Further, it may be 10 ⁶ Ω or less at 23 ° C. Furthermore, it may be 10 ³ Ω or less. These can be said to be conductive rather than low in chargeability. A low surface resistivity is preferable because it is difficult to be charged. This is because, when an insulating plate-like object (for example, a glass substrate) is conveyed, there is a possibility that troubles may occur in the conveyance of the plate-like object due to the interaction with the plate-like object due to electrical factors. . Examples of such resins include resins reinforced with carbon fibers, particularly polyphenylene ether (PPE).

  The composite material preferably has a tensile strength of 70 to 100 MPa (ASTM GEPJ method) at 23 ° C. Further, a material having a bending strength of 90 to 130 MPa (ASTM D790) at 23 ° C. is preferable. Further, a material having a flexural modulus of 4000 to 10,000 MPa (ASTM D790) at 23 ° C. is preferable.

  Moreover, although a metal fiber etc. can be used as a conductive fiber other than a carbon fiber, a carbon fiber is more preferable.

  The material for forming the nozzle plate is not particularly limited except that the charging property is low (in other words, it has conductivity) as described above. However, in view of its ease of molding (especially easy formation of complex shapes), sealing properties such as engaging portions that require airtightness, and weight, etc., synthetic resin is more preferable. As such synthetic resins, ordinary plastics, engineering plastics and the like can be applied, and more specifically, acrylic resins, epoxy resins, modified PPE (polyphenylene ether) resins, PS (polystyrene) resins, and other resins are applied. it can. Moreover, such a nozzle plate can be integrally molded by injection molding. Since these resins alone may not have sufficient conductivity, a conductive filler (for example, carbon fiber, metal powder, etc.) can be mixed when conductivity is required.

(10) An airflow levitation device that levitates a plate-like object by gas injected from a plurality of inclined injection holes and conveys the plate-like object in a predetermined direction while maintaining the non-contact state, and any one of (1) to (9) above An air levitation device including the nozzle plate described in 1 can be provided.

(11) The nozzle plate is substantially parallel to the plate-like object at predetermined first and second intervals in the conveying direction of the plate-like object and in a direction substantially perpendicular thereto. As described above, the air levitation device according to (10) can be provided, wherein a plurality of the flat portions are arranged to have the same height.
(12) The air flow levitation device can be provided in which the first interval is narrower than the second interval.

  The predetermined interval is determined by the levitation force applied by each nozzle plate to the conveyed plate-like object, the characteristics of the conveyed plate-like object, and the like. When the plate-like object to be conveyed is thin and the plate surface is easily bent, it is more difficult to convey with the airflow device. In the case of a transported object having a relatively high rigidity in the thickness direction, even if the gas pressure between the transported object and the transport surface is not uniform, the transported object is less bent, so that the transport is relatively easy. . If the rigidity in the thickness direction is low, it is necessary to make the gas pressure between the object to be transported and the transport surface uniform if it is transported in a flat state. However, in order to make the gas pressure uniform, not only a larger number of injection holes are required, but also the precise control of the injection pressures and the uniform arrangement of the openings of such injection holes on the conveying surface are required. Necessary and productivity is not necessarily high. On the contrary, if such a conveyed object is bent so as to be regularly waved, there is an advantage that rigidity against bending is increased in a direction in which wave ridges and valleys are continuous. For example, when undulation is performed in a direction perpendicular to the transport direction, since the ridges and valleys of the waves are continuous in the transport direction, it is possible to prevent the transport tip from drooping downward. In addition, it is considered that an air reservoir is formed by the object to be conveyed which is bent so as to be wrapped with the flat portion due to the bending, and the air pressure of the air reservoir can be easily kept high.

(13) The airflow levitation device according to (11) or (12) above, wherein the flat portion of the nozzle plate is at the highest position on the side facing the plate-like object.

  Since the above-described levitation force is unlikely to be generated at positions other than the nozzle plates, the plates are bent downward due to the weight of the plate-like material to be transported at positions other than the nozzle plates. That is, when viewed from the side (when viewed from the side), the plate-like object can have a shape that waves in the transport direction and / or the transverse direction.

(14) In the airflow conveyance system including the second airflow levitation device connected to the airflow levitation device according to any one of (10) to (13), the airflow levitation device and the second airflow levitation device are respectively 1st and 2nd conveyance surface which conveys a plate-shaped object, The 2nd above-mentioned air current levitation device contains a nozzle plate given in either of the above (1) to (9), The above-mentioned 1st A conveyance surface and a 2nd conveyance surface are prescribed | regulated by the nozzle plate as described in any of said (1) to (9) which comprises each airflow levitation apparatus, The said plate-shaped object is said 1st conveyance surface. The air transport system can be provided in which the first transport surface is at a higher position than the second transport surface.

(15) In the airflow conveying method in which a plate-like object is levitated by a gas ejected from a plurality of injection holes provided on a conveying surface and is conveyed in a predetermined conveying direction while being maintained in a substantially non-contact state, the plate-like It is possible to provide an airflow conveying method characterized by causing an object to wave in a direction substantially perpendicular to the conveying direction.

  When waves are struck in this way, it is possible to prevent the substrate from sagging at the front end in the transport direction. When the substrate becomes larger, the deflection due to its own weight increases. For example, when the substrate size exceeds 500 × 600, when the thickness is 0.7 mm, a deflection of 10 mm or more is generally generated even when the four corners of the substrate are supported. To do. When the flying height is sufficient, there is no problem because it is transported without contacting the transport surface, but it is necessary to inject a large amount and / or high-speed air used for flying. Examples of the flying height that does not hinder the conveyance include 1 to 2 mm. However, when such a substrate is transported between two continuous levitation units, smooth transfer from the first levitation unit to the next second levitation unit is not always guaranteed only by this levitation height. Furthermore, even if the flying height is 2 mm at the air blowing position on a large substrate (for example, 1500 mm × 1850 mm), the bent substrate may come into contact with the transport surface at a distance of 60 mm. However, if the substrate is waved in a direction substantially perpendicular to the transport direction, the moment of inertia in the cross section increases in the transport direction, and the rigidity against bending (ie, bending) increases.

(16) The plurality of injection holes are injection holes provided in the nozzle plate according to any one of claims 1 to 9, wherein the nozzle plate substantially extends in the transport direction of the plate-like object. In the orthogonal direction, a plurality of first and second intervals are provided so as to be substantially parallel to the plate-like object, and the first interval is the second interval. The plate-like object undulates in a direction substantially perpendicular to the transport direction by bending downward at a position where the second interval is provided. (15) The airflow conveying method according to the description can be provided.

  Usually, when a flat plate material and a corrugated plate material are compared, the latter has higher strength against bending. Therefore, when the substrate is transported while being held in a flat state, the front end portion in the transport direction is likely to sag. However, dripping can be prevented by making the substrate into a wave shape, and smooth conveyance is realized. Moreover, even if the substrate size handled by using the above-mentioned nozzle plate changes, the desired wave shape of the substrate can be maintained by changing the arrangement of the nozzle plate.

(17) When the plate-like object is conveyed along the predetermined conveyance direction from the conveyance surface to the second conveyance surface, the corrugated form of the plate-like object formed on the conveyance surface is The airflow conveying method according to (15) or (16) can be provided, which is also maintained on the second conveying surface.

  By maintaining the wavy shape (form) of the substrate between the two transport surfaces, it is possible to more stably prevent the front end portion from sagging with respect to the transport direction of the substrate.

  According to the present invention, the nozzle plate of the airflow conveyance device can be manufactured at low cost. For example, it is possible to form an inclined gas flow path at the same time when the nozzle plate is formed without opening the inclined injection hole with a drill. Further, when the opening of the inclined injection hole is provided in the wall forming the groove, the surface on which the opening is provided and the gas flow path direction of the inclined injection hole form an angle that is substantially perpendicular or substantially perpendicular. The inclined injection hole can be formed relatively easily. Moreover, even if it is a low voltage | pressure or a small amount of airflow, the plate-shaped object conveyed can be levitated efficiently. Moreover, the airflow conveying apparatus which can float (and convey) the large sized to-be-conveyed object using this nozzle plate can be provided. Therefore, if such an airflow conveying apparatus is used, it becomes possible to configure a conveying apparatus that can easily change the air injection position according to the substrate size. Therefore, not only the freedom degree of a conveying apparatus increases, but conveying apparatus itself can provide at low cost.

  In addition, when at least the flat portion adjacent to the object to be conveyed has low chargeability (or conductivity), the flat portion and the entire nozzle plate can be prevented from being charged. For example, when the object to be conveyed is a dielectric material such as glass, it is possible to prevent such an adverse effect that the object to be conveyed is attracted to the flat portion by charging.

Further, the following may be included in the present invention.
An airflow conveying device capable of levitating a plate-like object, comprising: a base for forming and / or supporting a conveying surface for levitating and supporting the plate-like object, the substrate comprising a plurality of openings on the conveying surface side A nozzle plate that is airtightly laid on each of the plurality of openings, and the nozzle plate floats on the conveyance surface side around the flat portion and the flat portion that forms the conveyance surface. A plurality of inclined injection holes for injecting the working gas, and the pressurized gas flowing from each of the plurality of openings is injected from the plurality of inclined injection holes as a levitation gas in a predetermined injection direction. It is possible to provide an airflow conveyance device characterized in that the airflow conveyance device is provided.

  Here, the base may support the nozzle plate as described above, and the upper surface of the base may directly constitute the transport surface. Further, as will be described in detail later, a panel having an upper surface constituting a conveyance surface may be supported. The base is provided with an opening for airtightly laying the nozzle plate, and gas can be injected from the injection hole through the opening. In order to lay airtightly, it is also effective to interpose intermediate materials such as packing and seals.

  Here, the injection hole may be a fine hole. Further, the injection hole may have a slit shape. In the case of pores, the flow of injected gas tends to be fast. On the other hand, in the slit shape, it is easy to inject a large amount of gas.

  The plurality of nozzle plates described above are substantially parallel to the plate-like object at predetermined first and second intervals, respectively, in the conveying direction of the plate-like object and in a direction substantially perpendicular thereto. As such, a plurality of the flat portions may be arranged with the same height. At this time, a panel plate having an upper surface arranged at the same height as the flat portion may be laid within the first and second intervals to constitute the transport surface. As described above, the transport surface is composed of an upper surface (including a flat portion) such as a panel or a nozzle plate, but the gas injected from the injection hole is a gap between the plate-like object and the transport surface. Can be held in. Accordingly, when a plate-like object warped upward is transported, the gap near the center line along the transport direction of the transport surface is increased. In order to give sufficient levitation force in this gap, the flow velocity of the gas to be injected is made sufficiently fast and depends on the momentum (that is, dynamic pressure) of the gas, or a large amount of high-pressure gas is sent to increase the static pressure. A method is conceivable. In the former case, pores are more preferable as the injection holes. In the latter case, a slit is more preferable as the injection hole.

  It is possible to use an integral member (for example, a plate, a block, etc.) having a flat upper surface for the conveying surface, but it is easier to change the design by combining the nozzle plate and panel as described above. Can be done. In addition, the conveyance surface can be configured at a lower cost.

It is a perspective view of a nozzle plate. It is a top view of a nozzle plate. It is a right view of a nozzle plate. It is a front view of a nozzle plate. It is a bottom view of a nozzle plate. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a figure which shows the model for understanding the force which the two-dimensional steady jet which curves along a free boundary exerts. It is a perspective view of the airflow conveying apparatus using a nozzle plate. It is a figure which shows the conveyance surface of the airflow conveying apparatus using a nozzle plate. It is a perspective view which shows the state in which the nozzle plate was attached to the base of an airflow conveying apparatus. It is a figure which shows the state which a plate-shaped object floats on the conveyance surface of the airflow conveying apparatus using a nozzle plate. It is a figure which shows the various patterns of the nozzle plate attached to the base of a conveyance levitation apparatus. It is a perspective view of another nozzle plate. It is a top view of another nozzle plate. It is a right view of another nozzle plate. It is a front view of another nozzle plate. It is a bottom view of another nozzle plate. It is AA-AA sectional drawing of FIG. It is BB-BB sectional drawing of FIG. It is a perspective view of another nozzle plate. It is a top view of another nozzle plate. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a top view of another nozzle plate. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a bottom view of another nozzle plate. It is a figure which shows the conveyance surface of another airflow conveying apparatus using a nozzle plate. It is a figure which shows the conveyance surface of another airflow conveying apparatus using a nozzle plate. It is the schematic which shows that a head droops between two airflow conveying apparatuses which convey a plate-shaped object. It is the schematic which shows making it wavy and convey between the two airflow conveying apparatuses which convey a plate-shaped object in the direction substantially perpendicular | vertical to a conveyance direction. It is the schematic equivalent to FIG. 32 of the airflow conveying apparatus using a nozzle plate. It is a perspective view of another airflow conveying apparatus using a nozzle plate. It is a top view of another nozzle plate (expansion nozzle plate). It is AA sectional drawing of FIG. It is a cross-sectional view with respect to the conveyance direction which shows a mode that the plate-shaped object which curved upward convexly floats. It is a disassembled perspective view which shows a nozzle plate being attached to the base of an airflow conveying apparatus. It is a disassembled perspective view which shows a nozzle plate being attached to another base.

Explanation of symbols

10, 11, 10 ′, 10 ″, 10a, 10b Nozzle plate 12 Base 14, 16 Groove 18 Flat portion 20 First surface 22 Second surface 24, 30 Inclined injection hole 24a Slit 26 as an inclined injection hole First Third surface 28 Fourth surface 32 Bolt hole 34 Recess 36 Air passage 50 Plate-like object 55 Substrate 60, 62 Panel 100, 120, 125, 127 Airflow transfer device 110, 111, 122, 124, 126, 128 Base 112 Prop 140, 150, 160 Airflow transfer device

  Embodiments of the present invention will be described below in more detail with reference to the drawings. In addition, the same code | symbol is used for the same element and the overlapping description is abbreviate | omitted.

  FIG. 1 is a perspective view showing a nozzle plate 10 which is one embodiment of the present invention. FIG. 2 is a top view of the nozzle plate 10. FIG. 3 is a right side view of the nozzle plate 10. Since the left side view appears symmetrically, it is omitted here. FIG. 4 is a front view of the nozzle plate 10. Since the rear view of the nozzle plate 10 appears symmetrically, it is omitted here. FIG. 5 is a bottom view of the nozzle plate. 6 is a cross-sectional view taken along the line AA in FIG. 7 is a cross-sectional view taken along the line BB in FIG.

  The nozzle plate 10 is normally used in a state where a flat plate is placed horizontally with the bottom surface shown in FIG. 5 as the bottom. Therefore, in the following description, the positional relationship such as up and down is expressed based on this state. That is, in the perspective view of FIG. 1, the upward direction is similarly upward in the actual description.

  The nozzle plate 10 is composed of a plate-like substrate 12 having an upper surface that is substantially square when viewed from above. Four grooves 14, 16, 14, 16 are formed in the vicinity of the four sides of the upper surface of the base 12 in a clockwise direction substantially parallel to the respective sides. These grooves 14, 16, 14, 16 surround the flat portion 18 in the middle of the upper surface. Each groove is a V-shaped groove having a V shape in a cross-sectional view. The groove 14 includes a first surface 20 located outside the base 12 and a second surface 22 located inside the base 12. These first and second surfaces 20 and 22 intersect or adjoin at the bottom of the V-shaped groove, and the opening angle made from these surfaces is about 90 degrees. The groove 14 extends from one end of the base 12 to the other end, and a V-shaped notch can be seen when viewed from the side (see FIG. 4).

  The first surface 20 described above is provided with a plurality of inclined injection holes 24 (ten in the present embodiment) at a predetermined interval substantially at the center of the surface width. In the present embodiment, the predetermined intervals are all the same (approximately one-tenth of the length of the groove 14), but all can be made different or a part can be made the same. As can be seen from the cross-sectional views (see FIGS. 6 and 7), the inclined injection hole 24 is opened substantially perpendicular to the first surface 20, and the length of the hole is the thickness of the first surface 20. It is substantially equal to the thickness (in this embodiment, about 1/50 of the length of one side of the base 12).

  A groove 16 extends in a direction perpendicular to the groove 14, and both ends of the groove 16 are defined where the groove 16 abuts. Similarly to the groove 14, the groove 16 includes a third surface 26 located outside the base 12 and a fourth surface 28 located inside the base 12. These third and fourth surfaces intersect or adjoin at the bottom of the V-shaped groove, and the opening angle made from these surfaces is about 90 degrees.

  The third surface 26 is provided with a plurality of inclined injection holes 30 (eight in the present embodiment) at a predetermined interval substantially at the center of the surface width. In this embodiment, the predetermined intervals are all the same (generally about one tenth of the length of one side of the base 12), but all can be made different or a part can be made the same. . Although there is no cross-sectional view showing the inclined injection hole 30, as in the case of the inclined injection hole 24 in the cross-sectional view shown in FIG. 7, the inclined injection hole 30 is opened substantially perpendicularly to the third surface 26. The length is substantially equal to the thickness of the third surface 26 (in this embodiment, about 1/50 of the length of one side of the base 12).

  A concave portion 34 is formed in the approximate center of the flat portion 18 at a depth of about one-tenth of the thickness of the base 12. The concave portion 34 is not particularly related to the function of the nozzle plate 10 and is used when the nozzle plate 10 is integrally formed. The nozzle plate 10 is made of a synthetic resin with low chargeability, such as a modified PPE resin.

  One bolt hole 32 is provided at each of the four corners of the flat portion 18, and a counterbore is made so that the head of the bolt is hidden, as can be seen from the sectional view (see FIG. 7). Further, a cylinder (or disc) 32 'having a low height protrudes from the bottom side (or back side) of the nozzle plate at a position opposite to the bolt hole 32 (see FIGS. 3 to 7). This is because when the nozzle plate 10 is bolted, the outer peripheral portion is sealed, but the cylinder 32 ′ protrudes from the surface (bottom surface) and the mounting surface of the base 110 abuts so that the flat mounting of the nozzle plate 10 can be performed with high accuracy. This is because it can be done. That is, it is difficult to ensure flatness when the nozzles are attached to the surfaces that come into contact with each other with a thick packing interposed therebetween.

  As shown in FIGS. 5 to 7, the inclined injection holes 24 and 30 penetrate the back side of the base 12 and communicate with the air passages 36 and 38, respectively. The air passage 36 is disposed on the back side of the groove 14 and is airtightly coupled to a base (described later) to which the nozzle plate 10 is attached by packing or the like, and the gas such as the air that is sent is inclined and injected. Supply to hole 24. The air passage 36 is larger than the diameter of the inclined injection hole 24 (in this embodiment, the length of the inclined injection hole is approximately the same as or slightly smaller), and the pressure in each inclined injection hole 24 is approximately the same. The supply air or the like is passed so as to inject gas. The groove 14 extends to both ends of one side of the base 12, and this air passage has a structure in which both ends are semicircular and closed in order to obtain airtightness. Therefore, among the inclined injection holes 24 provided in the groove 14, the inclined injection holes 24 at both ends are slightly longer than the other. Therefore, those at both ends of the inclined injection holes 24 shown in FIG. 5 are located slightly away from the longitudinal center axis of the air passage 36. Note that a space 46 that appears in a cross shape in the center in FIG. 5 is provided on the air passage side of the nozzle plate 10. In order to prevent gas leakage from the bolt holes 32, the rectangular members 42 separated by the cross shape are pressed against each other while maintaining airtightness with the opposing members of the base to which the nozzle plate 10 is attached by packing. It becomes.

  Here, the place considered to be an air reservoir may include approximately the center of the flat portion 18 or the recess 34. Further, even outside the recess 34, there may be an air reservoir on the flat portion 18, and the flat portion 18 between the bolt holes 32 at the four corners may also be an air reservoir. If the effect of this air accumulation is generally considered, it is easy to understand when considering a model as shown in FIG.

  The nozzle plate in this example was prepared using a modified PPE resin (trade name: Noryl CF series (carbon fiber reinforced), model number: NC208) manufactured by Nippon GE Plastics.

FIG. 8 is a model for understanding the force exerted by a two-dimensional steady jet that bends along a free boundary. Here, it is assumed that the plate B having nozzles at both ends is at a distance h on the stationary infinite plane C. Pc is the pressure between both sides of B and C, Pa is the pressure on the outer periphery, and the area of the plate B is A. At this time, the force F received by the plate B is
F = (Pc−Pa) × A + ρ × Q × v × cos θ (Equation 1)
It is. Further, the pressure difference Pc-Pa is expressed as follows:
Pc−Pa = ρ × t × v ² × (1 + sin θ) / h (Expression 2)
It is.

In the present embodiment, unlike the model of FIG. 8, the jet is not a belt but a beam, and spreads after injection. In addition, since it is a three-dimensional flow and the length of one side is not so long, the edge effect cannot be ignored, so it is not always accurate to approximate with a two-dimensional jet model, Conceivable. Here, since the state in which the state of FIG. 8 is turned upside down corresponds to the case of this embodiment, the nozzle plate corresponds to the plate B. Therefore, the force received by the plate-like object that is the object to be conveyed does not blow a jet, and therefore is caused by the difference between the pressure between the two surfaces and the surrounding pressure (pressure difference). That is,
F (plate-like object) = (Pc−Pa) × (area pressed by Pc pressure) (Equation 3)
It becomes.

  From Equation 3 and Equation 2, it can be seen that the levitation force increases as the pressure difference increases, and the levitation force increases as the injection speed v increases (especially, the effect is squared). In general, since the injection speed is approximately proportional to the pressure to be pushed out, the levitation force is expected to increase when the injection is performed at a high pressure and the injection direction is gathered as a beam of injection gas. As modeled in FIG. 8, it can be expected that the pressure of the air pool can be maintained high by the flow of the opposed jet gas. Therefore, it is considered that it is preferable to provide grooves on four sides and provide nozzle holes on each of the two sides, as will be described later, rather than a nozzle plate having grooves on two opposite sides and providing nozzle holes.

  Also, from Equation 2, the levitation force seems to be higher when θ approaches 90 degrees, but it is close to 90 degrees (substantially horizontal) due to other factors such as insufficient width t, for example. The case is less preferred.

  FIG. 9 shows a main part of an airflow conveying device (airflow levitation device) 100 using the nozzle plate 10. Each nozzle plate 10 is detachably mounted on a base 110 containing an air chamber. The nozzle plate 10 and the base 110 mounting opening (not shown) are attached with a rubber packing interposed therebetween. The base 110 is supported substantially horizontally by a column 112 at a predetermined height. The predetermined height is adjusted for each support column 112 so that the plurality of bases 110 in the drawing align the height of the upper surface of the nozzle plate 10. Within each column 112 is a pipe (not shown) through which compressed air passes, which is coupled to an L-shaped pipe 116 from which compressed air flows into the air chamber of the base 110. It is sent. Each support column 112 is installed at a predetermined interval in the front, rear, left, and right, and forms a preferable pattern by the nozzle plate 10 in a top view. Each column 112 is erected on a frame 114 installed on a floor surface that is substantially horizontal.

  Although not shown in FIG. 9, a plate-like object to be conveyed floats on the conveying surface of the airflow conveying device (airflow levitation device) 100 due to the levitating force generated by the nozzle plate 10 installed in a predetermined pattern. And transported almost horizontally.

  FIG. 10 is a top view of a conveyance surface (upper surface) of an airflow conveyance device (airflow levitation device) 120 according to another embodiment. In the figure, ten vertically long bases 122 are arranged with both end surfaces aligned in the horizontal direction. In the figure, numbers (1) to (10) are assigned from left to right. On the left side of the base 122 of (1), the conveyance direction of the object to be conveyed is indicated by an arrow P. The nozzle plates 10 and 11 are arranged in a predetermined pattern on each base 122. The flat portions 18 of these nozzle plates 10 and 11 constitute the upper surface which is the transport surface substantially horizontally. The nozzle plate 11 is provided with the grooves 14 and the injection holes 24 only on two opposing sides. However, instead of these nozzle plates 11, the nozzle plates 10 provided with the grooves 14, 16 and the injection holes 24, 30 on the four sides can be arranged. In addition, it is possible that the levitation force can be increased with the same air flow rate, which is more preferable.

  The nozzle pattern of FIG. 10 is a pattern in which rows of 2: 4: 2 are arranged at predetermined intervals in the transport direction. This predetermined interval can be changed in the same manner as the 2: 4: 2 pattern interval, and can be made variable according to the situation. A and C in the figure are positions at which how much the plate-like object has floated in the evaluation experiment. Although depending on various conditions, a flying height of about 0.1 to 3.0 mm could be secured. Further, as can be seen from this figure, since the levitation force does not occur in the place where the nozzle plate 10 or 11 does not exist, the plate-like object is easily bent downward by its own weight. Therefore, if it is a thin plate-shaped object, it will float in the place with the nozzle plate 10 or 11, and will bend in the downward direction in another place, and will exhibit the shape which hits a wave. This wavy shape can occur in both the vertical direction and the horizontal direction in the figure, and in consideration of the space opened between the nozzle plates 10 and 11, a longitudinal wave, a transverse wave, or a mottled pattern (or checkered pattern) Pattern).

  Such a corrugated shape is not preferable because if the degree becomes too severe, an undesirable stress (stress) is applied to the plate-like object. However, if the generated stress is within an allowable range, there is an effect of increasing the bending rigidity in the direction orthogonal to the waving direction, which is considered preferable.

  FIG. 11 shows a state in which the nozzle plate 11 is attached to the base 124. As described above, the nozzle plate 11 differs from the nozzle plate 10 only in that there are no grooves 16 and injection holes 30. On the base 124, the next nozzle plate 11 is disposed at a distance of about one third of the length of one side of the nozzle plate 11.

  FIG. 12 shows a state of the plate-like object 50 floating on the nozzle plate 10 arranged on the base 126 in a side view. At the position 52 where the nozzle plate 10 is located, the plate-like object 50 bulges upward, but at the position 54 that is located between the nozzle plates 10, it is recessed in a concave shape. This is because the plate shape is sufficiently thin and can be bent, but the entire plate-like object 50 has a wave-like shape. In this shape, when bending in the direction from the front to the back in the drawing, that is, in the direction substantially perpendicular to the undulating shape, the bending rigidity is increased by the amount of the undulating shape and the bending is less likely to be advantageous.

  In addition, in this figure, the wavy shape of the longitudinal direction of the base 126 is shown. However, it goes without saying that a similar corrugated shape can be formed by arranging the base 126 at a predetermined interval. Here, for the sake of simplicity, detailed illustration is omitted, but the base 126 of FIG. 12 does not continue long, but there is a base 126 only under the nozzle plate 10 and between the two nozzle plates 10. There is nothing in the figure that corresponds to such a figure.

  FIG. 13 shows the conditions of the levitation experiment conducted under various conditions. The nozzle plates 10 and 11 are arranged on the base 122 according to the respective conditions. Here, although there is only one base 122 and nozzle plates 10 and 11 shown in FIG. 13 for each condition, ten pieces are arranged in the transport direction and evaluated in the same manner as in FIG. The substrates 1 to 6 are one type of substrate, and the substrates 7 and 8 are other types of substrates. Further, in the blowers 1500 and 2200, 2200 has a higher air flow rate. Here, the nozzle plate 11 is also used, but it is more preferable to use the nozzle plate 10 as a whole.

  FIG. 14 is a perspective view showing another nozzle plate 10 ′ according to the embodiment of the present invention. FIG. 15 is a top view of the nozzle plate 10 ′. FIG. 16 is a right side view of the nozzle plate 10 ′. Since the left side view appears symmetrically, it is omitted here. FIG. 17 is a front view of the nozzle plate 10 ′. Since the rear view of the nozzle plate 10 appears symmetrically, it is omitted here. FIG. 18 is a bottom view of the nozzle plate. 19 is a cross-sectional view taken along the line AA-AA in FIG. 20 is a cross-sectional view taken along the line BB-BB in FIG.

  As with the nozzle plate 10 of FIG. 1 and the like, this nozzle plate 10 'is normally used in a state where a flat plate is placed horizontally with the bottom surface shown in FIG. 18 as the bottom. Therefore, in the following description, the positional relationship such as up and down is expressed based on this state. That is, in the perspective view of FIG. 14, the upward direction is similarly upward in the actual description.

  The nozzle plate 10 ′ has basically the same shape as the nozzle plate 10. In particular, the top view is the same except that the corners of the four sides are chamfered (ratio of the side surface 1 to the top surface 2) 13, so the same members are denoted by the same reference numerals, and overlapping explanations are omitted. Omit.

  The chamfer 13 has a plate shape when the plate-like material conveyed on the nozzle plate 10 ′ cannot sufficiently support the peripheral edge of the nozzle plate 10 ′ by gas pressure from below. Even if an object contacts the nozzle plate 10 ', there is an effect of preventing damage.

  As shown in FIGS. 18 to 20, the inclined injection holes 24, 30 penetrate the back side of the nozzle plate 10 'and communicate with the air passages 36', 38 ', respectively. The air passages 36 ′ and 38 ′ are arranged on the back side of the groove 14 and are airtightly coupled to a base to which the nozzle plate 10 ′ is attached by packing or the like, and the gas such as air sent is inclined. Supply to the injection hole 24. The air passages 36 ′ and 38 ′ are larger than the diameter of the inclined injection holes 24 (in the present embodiment, as small as or slightly smaller than the length of the hole (gas flow path)), and are almost in the inclined injection holes 24. Supply air or the like is passed so as to inject the gas at the same pressure. The air passages 36 ′ and 38 ′ are kept airtight between a wall 37 along the four sides on the back side of the nozzle plate 10 ′ and a wall 39 extending along the four sides on the inner side. Yes. In addition to the walls 37 and 39, reinforcing ribs are erected in a cross shape around the bolt holes 32 in a rectangular frame 42 'corresponding to the rectangular member 42 in FIG. Further, a space 46 ′ is similarly provided in the place where the space 46 in FIG. 5, and the wall 43 is also erected as a cross as a reinforcing member of the space.

  Compared with the nozzle plate 10 shown in FIG. 1 and the like, this nozzle plate 10 ′ has a reduced thickness, can reduce the material used, is lighter, and is advantageous in terms of cost. . In addition, shrinkage in injection molding or the like can be reduced by reducing the wall thickness.

  FIG. 21 is a perspective view showing another nozzle plate 10 ″ according to the embodiment of the present invention. FIG. 22 is a top view of the nozzle plate 10 ″. Since the right side view of the nozzle plate 10 ″ is the same as FIG. 3, FIG. 3 can be the right side view of the nozzle plate 10 ″. Since the left side view of the nozzle plate 10 ″ appears symmetrically, it is omitted here. Since the bottom view of the nozzle plate 10 ″ is the same as FIG. 5, FIG. 5 can be a bottom view of the nozzle plate 10 ″. 23 is a cross-sectional view taken along line AA in FIG. 24 is a cross-sectional view taken along the line BB in FIG.

  Similar to the nozzle plate 10 in FIG. 1 and the like, this nozzle plate 10 ″ is normally used in a state where a flat plate is placed horizontally with the back surface shown in FIG. 5 as the bottom. Therefore, in the following description, the positional relationship such as up and down is expressed based on this state. That is, in the perspective view of FIG. 21, the upward direction is similarly upward in the actual description. Accordingly, the surface expressed as a front view in FIG. 21 is treated as the upper surface in the following description.

  The nozzle plate 10 ″ has basically the same shape as the nozzle plate 10 except that no groove is formed on the upper surface. Therefore, the same member is shown with the same code | symbol, and the overlapping description is omitted below.

  As shown in FIGS. 21 to 24, the inclined injection holes 24 ′ and 30 ′ pass through the back side of the nozzle plate 10 ″ and communicate with the air passages 36 and 38 (see FIG. 5), respectively. The air passages 36 and 38 are arranged on the lower side (back side) of the nozzle plate 10 ″, and are airtightly coupled to a base to which the nozzle plate 10 ″ is attached by packing or the like, and the air that is sent Gas is supplied to each inclined injection hole 24 ', 30'. The air passages 36 and 38 are larger than the diameter of the inclined injection hole 24 '(in this embodiment, the length of the hole (gas flow path) is almost the same or slightly smaller), and are almost in each inclined injection hole 24'. Supply air or the like is passed so as to inject the gas at the same pressure.

  As shown in FIG. 24, the gas flow paths of the inclined injection holes 24 ′ and 30 ′ can be formed longer as long as there are no grooves. Thereby, the injection directionality of the injection gas becomes high, and it is expected that the injection gas reaches the air reservoir at a higher speed. Such a hole can be formed by a conventional drill, but can also be manufactured by integral molding by a resin injection molding method.

  25 to 28 illustrate a nozzle plate in which the inclined injection holes 24a are slit-shaped. FIG. 25 is a top view of the nozzle plate. 26 shows a cross section AA in FIG. 25, and FIG. 27 shows a cross section BB in FIG. FIG. 28 is a bottom view of the nozzle plate. Since the inclined injection hole 24a is basically the same as that shown in FIGS. 1 to 7 except that the inclined injection hole 24a has a slit shape, redundant description is omitted.

  As shown in FIG. 25, the slit-shaped inclined injection hole 24 a has an opening formed in a slit shape on the first wall forming the grooves 14 and 16. In this figure, for the sake of clarity, it is shown larger than the actual width of the slit, but the total cross-sectional area per nozzle plate is larger than the previous pores. Recognize. For this reason, although a large amount of gas can be injected, since a large amount is injected, the injection speed or the injection pressure tends to be small. As can be seen from FIGS. 26 and 27, the inclined injection hole 24a is inclined in a C shape obliquely from the first wall. FIG. 28 shows a state where slit-shaped inclined injection holes 24a are also opened on the bottom surface. As described above, any shape such as a slit shape and a pore shape may be used, but it is preferable to select according to the respective characteristics. Therefore, it is possible to mix and arrange slit-like and fine pore-shaped inclined injection holes on the same nozzle plate.

  FIG. 29 is a top view of the conveyance surface (upper surface) of the airflow conveyance device 140 of another embodiment. In the drawing, 18 rows of vertically long bases 122 are arranged in parallel in the horizontal direction, and the rows are arranged in parallel. In the figure, numbers (1) to (18) are assigned from left to right. Although the nozzle plates 10 ′ are arranged in a predetermined pattern on each base 122, the nozzle plates 10 may be arranged or a combination thereof may be arranged. The flat portions 18 of these nozzle plates 10 'constitute the upper surface, which is the conveying surface, substantially horizontally. A part of the upper surface of another transfer device 150 is drawn on the left side of the transfer device 140. Details will be described later with reference to FIG.

  The nozzle pattern by the nozzle plate of FIG. 29 is a pattern in which 3: 3 rows are arranged at predetermined intervals in the transport direction. This predetermined interval can be changed in the same manner as the 3: 3 pattern interval, and can be made variable according to the situation. A and C in the figure are positions at which how much the plate-like object has floated in the evaluation experiment. Although it depends on various conditions, a flying height of about 0.1 to 3.0 mm can be generally secured. Further, as described with reference to FIG. 10, since no levitation force is generated in a place where the nozzle plate 10 'is not present, the plate-like object is easily bent downward by its own weight. Therefore, if it is a thin plate-like object, it will float in the place where the nozzle plate 10 ′ is located and bend downward in another place, and will exhibit a wave-like shape. This wavy shape can occur in both the vertical direction and the horizontal direction in the figure, and in consideration of the space opened between the nozzle plates 10 ', the vertical wave, the horizontal wave, or the mottled pattern (or checkered pattern) ).

  FIG. 30 is a top view of the conveyance surface (upper surface) of the airflow conveyance device 150 of another embodiment. In the figure, 24 rows of vertically long bases (not shown) are arranged in parallel, with rows formed by aligning both end faces in the horizontal direction. In the figure, numbers (1) to (24) are assigned from left to right. Although the nozzle plates 10 ′ are arranged in a predetermined pattern on each base 122, the nozzle plates 10 may be arranged or a combination thereof may be arranged. The flat portions 18 of these nozzle plates 10 'constitute the upper surface, which is the conveying surface, substantially horizontally.

  As shown in FIG. 29, if the width orthogonal to the transport direction (for example, right to left in the figure) is aligned with the width of the transport device 140, the plate-like member that is the transport object is removed from the transport device 150. It can be moved to 29 transport devices 140. At this time, as shown in FIG. 29, the width of the conveyance device 150 is slightly wider. This is in order to bring both conveying devices 140 and 150 as close as possible. Further, it is preferable that the transport surface of the transport device 150 be slightly higher (for example, about 1 mm) than the transport surface of the transport device 140 in consideration of sagging of the plate-like object during the movement.

  FIG. 31 schematically illustrates a state where the plate-like object 50 is transported from the airflow conveying device (airflow levitation device) 125 to the airflow conveying device (airflow levitation device) 127 in a flat state. An injection port 24 is opened on the conveyance surface of each of the airflow conveyance devices 125 and 127 and injects air. The plate-like object 50 floats due to the jetted air, but since the floating air is not jetted between the airflow conveying devices 125 and 127, the tip portion hangs down by its own weight as shown in the figure. On the other hand, in FIG. 32, the blowout of air from the plurality of injection ports 24 is adjusted so that the plate-like object has a wave shape. The wave shape is formed in a direction substantially perpendicular to the conveying direction from the airflow conveying device 125 to 127. For this reason, it turns out that a front-end | tip part does not droop.

  FIG. 33 performs the same conveyance as that in FIG. 32 using the nozzle plate 10 ′ of the present invention to the airflow conveying devices 125 ′ to 127 ′. In this case, it can be seen that the corrugated shape of the plate-like object 50 can be freely formed by appropriately changing the arrangement of the nozzle plate 10 ′. When the nozzle plate 10 ′ is used in this way, it is not necessary to adjust the air blowing from the injection port or to open the air injection port in a predetermined pattern, and more easily match the characteristics of the plate-like object 50. Thus, the conveying surfaces of the airflow conveying devices 125 ′ to 127 ′ can be designed.

  FIG. 34 shows a main part of the airflow transfer device 160 using the nozzle plates 10 and 10a. Each nozzle plate 10, 10a is detachably mounted on a base 110 containing an air chamber. Compared with the airflow conveying apparatus 100 of FIG. 9, only the point which uses the panels 60 and 62 and the nozzle plate 10a is different, and the overlapping description is abbreviate | omitted. The panel 60 may be a thin plate arranged in the direction along the transport direction, and the upper surface thereof is flat with the flat portion of the nozzle plate 10. The material of the panel 60 is not particularly limited, but is preferably a gas-impermeable material that can hold air stored under a plate-like object (not shown) to be conveyed for at least a predetermined time. For example, the same material as the nozzle plate 10 may be used. On the other hand, as shown in FIGS. 35 and 36, the panel 62 is a thin plate attached like both wings on both sides of the nozzle plate of FIG. The material and characteristics of the thin plate are the same as those of the panel 60. 35 and 36, the panel 62 is formed integrally with the nozzle plate 10a and is made of the same material. However, it is also possible to use separate members and bond the panel 62 on the side end surface of the nozzle plate 10a by bonding, welding or the like. In consideration of strength, integral molding is more preferable.

  As shown in FIGS. 9 and 10, the conveying surfaces of the conveying devices 100 and 120 are uneven surfaces including a convex portion with a nozzle plate and a concave portion with no nozzle plate by disposing a nozzle plate. Therefore, the gas (for example, air) blown out from the nozzle plate in the convex portion easily escapes from the concave portion without the nozzle plate. Therefore, it is possible to use a means for weakening the levitation force in order to create a wave shape of the object to be conveyed in the conveying surface. However, when the air injection amount is not sufficient, the levitation force cannot be sufficiently obtained, and it may be difficult to maintain the non-contact state. Therefore, the levitation force can be increased by laying a panel 60 having an upper surface at a position equivalent to the flat portion of the nozzle plate so as to fill the concave portion serving as the air escape path. Since the panel 60 is laid along the transport direction at a position where the nozzle plate 10 does not exist, the laying is easy.

  On the other hand, it is difficult to support the base plate by laying a similar panel at a position where the nozzle plate 10 is arranged in a jumping manner. Therefore, the nozzle plate 10a in which the panels 62 are attached to both sides of the laid nozzle plate 10 can be used. Such a deformed nozzle plate can easily fill the gap and make the transport surface almost flat at low cost. Thus, when the whole is made flat with the panels 60 and 62, sufficient floating force can be obtained with the smallest amount of air (flow velocity and flow rate). For example, in the transport apparatus 100a that transports the upwardly convex substrate 55 as shown in FIG. 37 with the airflow 57, the warped substrate 55 is lifted to an extent that does not hinder the transport without particularly increasing the amount of air. Can do.

  Here, an example is shown in which all the concave portions are covered with panels, but the panels may be spread only on some of the concave portions, or some of the panels may be removed from the flat conveyance surface. At this time, it is preferable to spread the panel so as to form a wave when the object (particularly a thin plate) as described above is conveyed. Where there is no panel, the levitation force is small, and in some places it is large. Therefore, it is preferable to lay a panel at a position corresponding to the top of the assumed wave and remove the panel from a position corresponding to the bottom.

  In order to form a simple cross-sectional shape of the conveyed object as shown in FIG. 37, it is not necessary to consider such a detailed arrangement of panels, but at least as shown in FIGS. 32 and 33. When undulating in a direction substantially perpendicular to the conveying direction, it is more preferable that the wave top appears at least twice. This is because a high levitation force can be required when there is only one time as shown in FIG. In addition, the difference in height of the object to be conveyed becomes large, and a sufficient clearance must be provided in the height direction in spite of conveying the thin plate. On the other hand, if the top of the wave appears at least twice, the overall height will be low, and the levitation force need not be very high. Further, the shape as shown in FIG. 37 is weak against local twisting, and the corrugated plate shape shown in FIGS. 32 and 33 is considered to improve the rigidity against twisting.

  FIG. 38 shows a state in which the nozzle plate 10b (nozzle plates 10, 10 ′, 10 ″, 10a) may be attached to the base 128 of the transport apparatus (for example, 100, 160). An opening 135 is provided in the base 128. The base 128 is shown in a partially cutaway view broken away on the right side, but there are other similar openings at locations not shown. The opening 135 is surrounded by the peripheral seal portions 136 and 138, and the rubber packing 134 is placed on the seal portions 136 and 138. This rubber packing 134 is in contact with the top of the peripheral wall (corresponding to the wall 37 in FIG. 18) on the bottom surface of the nozzle plate 10b to ensure airtightness.

  In the opening 135, a fixing member 132a for holding the nozzle plate 10b is disposed at a position that meets the bolt hole 32 of the nozzle plate 10b, and further, a peripheral portion (on the bottom surface side of the bolt hole 32) via the rubber packing 133 ( For example, it contacts the bottom surface of the cylinder 32 ′ in FIG. 19 and the like to prevent gas leakage from the bolt hole 32. For example, when the bolt 132b is screwed into the screw hole of the fixing member 132a and tightened, the rubber packing 134 is interposed, and the opening 135 is closed in an airtight state. On the other hand, the rubber packing 133 is sandwiched between a bolt receiving seat surface (bottom surface side) slightly protruding from the basic bottom surface of the nozzle plate 10b and the upper end peripheral portion 132 (may be slightly flanged) of the screw hole. Leakage from the hole 32 is prevented. As described above, since the peripheral edge corresponding to the bottom surface of the cylinder 32 ′ in FIG. 19 protrudes slightly, even if the fixing member 132 a is slightly inside, the airtightness can be sufficiently secured. The base 128 including the opening 135 functions as a plenum and can reduce pressure fluctuations. Pressurized air sent from the opening 135 is introduced from the bottom opening of each inclined injection hole 24 ′ and is injected from each opening on the surface.

  FIG. 39 shows a state in which the nozzle plate 10c (the nozzle plate 10 or the like having a bottom view as shown in FIG. 5) may be attached to another type of base 129 of the transfer device (for example, 100 or 160). Yes. The base 129 is provided with an opening 135a and four screw holes 132a arranged so as to surround the opening 135a. The base 129 is shown in a partially cutaway view broken away on the right side, but is provided with other similar openings and screw hole sets at locations not shown. Around the opening 135a, a laying surface 129a on which the nozzle plate 10c is arranged spreads, and the rubber packing 134a is placed on the laying surface 129a with the screw hole 132a aligned with the opening 134b. The rubber packing 134a is in contact with the top of the peripheral wall (corresponding to the wall 37 in FIG. 18 and the peripheral wall in FIG. 5) on the bottom surface of the nozzle plate 10c, thereby ensuring airtightness.

  The opening 135a functions as a duct that feeds air, from the opening 134c of the rubber packing 134a to the bottom opening of each inclined injection hole 24 ′ via the bottom air passage (for example, 36 and 38 in FIG. 5). Air is sent in. The peripheral portion of the bottom surface side of the bolt hole 32 (for example, the bottom surface of the cylinder 32 ′ in FIG. 19 or the like) passes through the opening 134b of the rubber packing 134a and directly contacts the peripheral portion 132c of the screw hole 132a of the laying surface 129a. The height position is strictly defined. Since the other surface (for example, the bottom surface of the rectangular member 42 in FIG. 5) contacts the remote portion 132d and the like slightly away from the screw hole 132a of the laying surface 129a via the rubber packing 134a, the leakage from the bolt hole 32 Can be prevented. At this time, the protrusion of the cylinder 32 ′ is made in anticipation of the thickness of the rubber packing 134 a, and the sealing by the rubber packing 134 a is performed with just the right tightening pressure. The interior of the base 129 functions as a plenum and can reduce pressure fluctuations.

As described above, in the levitation device and / or the conveyance device using the nozzle plate of the present invention, the plate-like object can be transferred to the levitation device and / or the conveyance device in accordance with the process of processing, and production in the production facility can be performed. Can be improved.

Claims (13)

An air current conveying device capable of floating a plate-like object,
A base for forming and / or supporting a conveying surface for levitating and supporting the plate-like object;
A nozzle plate hermetically laid in at least one of the openings provided on the transport surface side of the base,
The nozzle plate is
A flat portion constituting the conveying surface, a plurality of inclined injection holes for injecting a floating gas to the conveying surface side around the flat portion, and a first wall and a second wall around the flat portion And a groove portion that is defined and formed ,
The opening of the inclined injection hole is formed in a first wall that defines the groove,
The inclined injection hole is formed to be substantially perpendicular to the first wall,
Pressurized gas that flows from each of the plurality of openings in the floating gas from said plurality of inclined injection holes, when virtually extended from the opening of the plurality of inclined injection holes, the first wall An airflow conveying device characterized in that the airflow is jetted in a jetting direction that does not directly contact the second wall that defines the groove portion facing each other . The groove includes a V-shaped groove having a predetermined opening angle by the first wall and the second wall,
The first wall and the second wall face each other and extend around the flat portion;
The air current conveying device according to claim 1, wherein the second wall is closer to the flat portion than the first wall. The inclined injection holes, pneumatic conveying apparatus according to claim 1 or 2, characterized in that the pores. The inclined injection holes, pneumatic conveying apparatus according to claim 1 or 2, characterized in that a slit shape. The nozzle plate has a rectangular plate shape with a predetermined thickness,
The airflow conveying device according to any one of claims 1 to 4 , wherein the side portion on the conveying surface side is chamfered with a predetermined size. The nozzle plate has a rectangular plate shape with a predetermined thickness,
The airflow conveying device according to any one of claims 1 to 5 , wherein the plurality of inclined injection holes are formed with a flat portion interposed therebetween. The nozzle plate includes at least one bolt hole having a counterbore recessed from the flat portion,
The bolt hole is formed so as to penetrate between a counterbore surface of the counterbore formed on the conveying surface side and an opposite surface formed on the opposite side facing the counterbore surface,
The nozzle plate by fastening members passing through the bolt holes, the facing surface is brought into contact with the holding member, according to any of claims 1 to 6, characterized in that fixed to the holding member Airflow transfer device. The flat portion of at least the nozzle plate, pneumatic conveying apparatus according to any one of claims 1 to 7, characterized in that it consists of low charge resin. The nozzle plate includes an outer peripheral wall extending along a peripheral edge defining an outer shape of the nozzle plate on the opposite side of the conveying surface,
The top of the outer peripheral wall defines the opposite surface of the nozzle plate;
The airflow conveying device according to claim 7 , wherein the facing surface protrudes from the opposite surface defined by the top of the outer peripheral wall. Said nozzle plate, in the conveying direction and the direction perpendicular thereto of the plate-like material, respectively at a predetermined first and second spacing, so as to be parallel against the platelet, each of the flat The airflow conveying device according to claim 1, wherein a plurality of portions are arranged with the same height. The airflow conveying device according to claim 10 , wherein the first interval is narrower than the second interval. The panel board having an upper surface aligned in a position of the flat portion equal to the height of the nozzle plate is laid on the first and second intervals, to claim 10 or 11, characterized in that it constitutes the transport surface The airflow conveying apparatus as described. Flat portion of the nozzle plate, pneumatic conveying apparatus according to claims 1 to 12, characterized in that in the highest position in the conveying surface.

Images