JP2000007151A - Work levitating structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a lightweight construction of a levitated transporting plate for levitating a work to be transported. SOLUTION: A levitated transporting plate for works is formed from thin metal sheet in such a structure that a box-shaped body 1 having an upper plate 12 furnished with a number of air feeding holes 11 is reinforced with ribs 13. For transporting works, an inclined nozzle 2 and guide part 3 are provided. The ribs 13 have a function of 'tracer guide' so as to control the shape and accuracy of the upper plate, and thereby the weight and cost can be reduced while the structure remains simple. Working precision of ribs accures good accuracy in the flatness of the upper plate 12 to constitute a transporting surface 12a, and it is also possible to comply with any shape of upper plate. The small thickness of upper plate 12 allows easy boring operation, and the air can blow out right over from the holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work floating structure for floating a flat work with gas blown from a floating surface.

[0002]

2. Description of the Related Art Various devices have been conventionally known as devices for floating a flat work such as a wafer or a ceramic printed circuit board by air in order to carry it cleanly. For example, a device that floats and conveys a ceramic printed circuit board by piercing air injection holes diagonally upward on a solid substrate carrier, placing a porous ceramic plate on an air chamber machined into a thick plate, and transmitting holes through it A device that blows air from and lifts and supports a work, and a device that controls the floating amount of a substrate by drilling holes through which a number of nozzles are inserted into a solid substrate mounting table and controlling the amount of air blown out (See, for example, JP-A-61-267394, JP-A-3-82322, and JP-A-62-530702).

The levitation plate used in the conventional levitation transport device, including the levitation transport device as described above, is usually formed by machining a solid plate material having a thickness of about 10 mm or more of aluminum by using a levitation nozzle or a propulsion nozzle. The inclined nozzle was formed. However, such a floating plate has high processing costs and material costs, and is expensive and heavy.

On the other hand, works such as LCD glass substrates are usually stacked in multiple layers and heat-treated efficiently. In this case as well, it is possible to heat-treat and transport the work while floating it, but with a heavy floating plate as in the past, the number of stages that can be stacked is limited, and it is not possible to heat-treat the work efficiently. There's a problem.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and has a simple structure, is inexpensive and lightweight, and can be used in a high-productivity heat treatment apparatus having a large number of loading stages. An object of the present invention is to provide a work floating structure capable of transporting a flat work in a state.

[0006]

According to the present invention, there is provided a work floating structure for floating a flat work by gas blown from an air bearing surface. A box-shaped body which forms the air bearing surface with a thin plate-shaped upper plate with a plurality of holes from which gas is blown out and receives internal pressure when the gas is introduced, and is processed so as to form the shape of the air bearing surface. A reinforcing plate having an end face joined to the upper plate, the reinforcing plate reinforcing the upper plate so that deformation of the upper plate when the internal pressure is received is limited.

According to a second aspect of the present invention, in addition to the above, there is provided a nozzle portion for blowing out a gas which is directed in a transport direction so that the workpiece can be transported.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a sectional shape of a floating transport plate to which the present invention is applied. The levitation transport plate, which is a work levitation structure, is a flat work LC with air, which is a gas blown from the transport surface 12a, which is a floating surface.
A work W such as a D glass substrate is configured to float, and has a thin sheet metal structure. That is, a box-shaped body 1 provided with a thin plate-shaped upper plate 12 having a plurality of holes, from which air is blown out, and having an air supply hole 11, receiving internal pressure when air is introduced, and an upper plate 12 when receiving internal pressure. And a keel-shaped rib 13 which is a reinforcing plate for reinforcing the deformation so as to limit the deformation. The inside of the box 1 is an air chamber 1a.
The reinforcing plate is preferably a rib-shaped plate as shown in the figure in order to reduce the weight as much as possible and allow air to flow therethrough, as compared with a plate stretched over the entire surface so as to partition the box-shaped body 1.

Further, the floating transfer plate of this embodiment has an inclined nozzle 2 as a nozzle section for blowing out a gas directed in the Y direction which is the transfer direction so that the work W can be transferred. In the present embodiment, the inclined nozzle 2 is connected to an air supply communication pipe 21 for supplying air of a different system from the air for floating.

At both ends of the upper plate 12, guide portions 3 are provided as guide members. The guide portion 3 is disposed so as to have a predetermined interval c between both ends in the X direction, which is the width direction of the work W, on the transport surface 12a of the upper plate 12. The interval c is an interval for guiding the work when the work is levitated and conveyed from the conveying surface, and is substantially equal to the floating amount h of the work. In FIG. 1, the above h and c are shown large, but the actual dimensions when the glass substrate or the like is floated and conveyed are usually several mm or less. The position of the guide unit 3 may be adjustable in the X direction.

The ribs 13 are formed in a straight line so as to form a flat surface in the present embodiment as the shape of the transfer surface 12a, and the upper plate 12 is formed.
In the example shown in FIG. 2, the end face 13a is provided with an appropriate pitch in the conveying direction so that the flatness of the conveying surface 12a can be maintained, as shown in the plane state of the floating conveying plate portion in FIG. Are provided. Box 1 and upper plate 12
Has sufficient strength by being reinforced by the ribs 13 in this manner. Therefore, for example, even when a large glass substrate of about 1 m square is floated and conveyed,
A stainless steel plate having a plate thickness of about 0.8 to 1.2 mm can be used. As a result, the floating transport plate can be manufactured lightly and inexpensively.

The ribs 13 are manufactured with high precision by laser processing or sheet metal processing. Therefore, the end face 13a has a sufficient straightness, and the flatness can be obtained by joining the upper plate 12 thereto. That is, for a large workpiece, it is not easy to obtain the flatness of the plate by machining, but the flatness of sufficient accuracy can be easily obtained by sheet metal working using a rib plate. Also, since the work can be levitated by a slight air pressure as described later, even if a sheet metal structure is adopted, no special covering or sealing is required. Therefore, the manufacturing process is also simple.

Although FIGS. 1 and 2 show an example in which the transfer surface 12a is a flat surface, the present invention can be advantageously applied to a case where the transfer surface is formed into another appropriate shape such as a concave curved surface. can do. That is, for example, when the transfer surface 12a is formed into a shape having a concave or convex arc-shaped cross section, the end surface 13a of the rib 13 is formed in an arc-shaped surface having the curvature, and the upper plate 1
The two are joined along by welding or the like. Also in this case, since the end surface 13a can be processed to a high-precision curvature by laser processing or the like, the curved-surface transport path can be easily and accurately manufactured.

FIG. 2 shows an example of the configuration of a work floating transfer device using the floating transfer plate of FIG. 1. The work floating transfer device of this embodiment is a device capable of heat-treating a work, and a temperature change which changes the temperature of supplied gas. As a gas supply system including means, a purifying means for purifying gas, and a circulating means for circulating at least a part of the gas, a floating blowing part 4 and a floating and conveying blowing part 5 are provided. Air is supplied to the transport plate, and the workpiece is floated and transported, and is heat-treated.

The floating air blower 4 is provided with a blower 41, an outside air inlet 42, an intermediate duct 43, an air blow opening 44, and a temperature changing means, which are provided in a machine room 7 which is partitioned and disposed in a casing 6. Heater 45, high-performance filter 46 as air purifying means, return duct portion 4 as circulating means
7 and an intake port 48. A certain amount of flow rate and wind pressure are required for the air for floating blowing supplied to the large number of air blowing holes 11. Therefore, the blower 41
For example, a turbo fan, a sirocco fan or the like having an appropriate type and size may be used.

The floating / conveying air blowing section 5 includes a compressed air introduction pipe 51a through which compressed air is sent from a compressed air source (not shown).
The suction filter 52, the electromagnetic valve 53, the air supply pipe 51b, the air supply communication pipe 21, the inclined nozzle 2, and the like shown in FIG. In this embodiment, an outside air heater 54 as the temperature changing unit and a clean filter 55 as the purifying unit are provided. When compressed air is used for the floating / transporting portion 5 in this manner, the amount of air and the pressure can be easily increased and decreased, and there is an advantage that the adjustment of the transport speed of the work is facilitated. However, the air source may be the same as that of the floating blower 4 so that the speed can be adjusted by a nozzle having a variable diameter and a variable inclination angle.

The inclined nozzle 2 is, as shown in FIG.
It has a shape inclined by an angle θ toward the Y direction, which is the transfer direction, and the force f ₀ due to the dynamic pressure of the air blown out from this shape causes the work support component fv in the vertical direction and the work transfer component in the Y direction. fy is generated. In addition, this nozzle may be a movable nozzle that can change the direction between when the workpiece floats and conveys and when the workpiece only floats. or,
Such a floating transfer nozzle may be provided not only in the central portion but also in other portions. Further, all the nozzles can be variable nozzles capable of floating conveyance.

The above-described work floating device is used as follows. Blower 4 when lifting the work
Drive 1 At this time, if it is necessary to heat the work, the heater 45 is turned on. The air blown out from the blower 41 is distributed by the intermediate duct 43, passes through the high-performance filter 46, and enters the air chamber 1 a in the box-shaped body 1 of the floating transfer plate from the blow opening 44. The inside is partitioned by ribs 13 so that air flows in the traveling direction in a well-balanced manner. At this time, if a pressure difference occurs between the respective rib sections, air is conducted through the holes of the ribs 13 to equalize the pressure.

The blower 41 has an air volume of 0.3 to 0.5 Nm ³ / mi if the work is a glass substrate of about 1 m square.
n. And a static pressure of about 10 to 30 mmAq. This air blows out from under the work through the air supply hole 11 to generate a total pressure consisting of the dynamic pressure of the air blown out to the lower surface of the work and the static pressure of the air filled therein. To surface. For example, the pressure receiving area of the work is 1m
² , if the total pressure to be generated is 10 mmAq, a force of 10 kgf which is three times or more of its own weight acts on the work, so that the work can be easily levitated.

FIG. 3 shows the relationship between the gravitational force G acting on the work W and the levitation force F. As (a), the when the conveying surface 12a and the distance between the workpiece W is small h _1, since the balloon air hardly flows out, the pressure P ₁ which occurs between them becomes high. As a result, increases work upward force F ₁ by the pressure P ₁ than the self-weight G of the workpiece W, the workpiece W is increased. The work W rises and the space below it rises from h ₁
, The air easily flows out from the four sides below the work, and as shown in (b), the pressure becomes P which is lower than P ₁ , and the resulting force becomes F which is smaller than F _1, and the weight G of the work becomes smaller. The work W is balanced and stabilized in a floating state.

In this case, since the upper plate 12 is made of a thin plate, the air blowing direction is blown at right angles to the conveying surface 12a without being affected by the sectional shape of the hole. Accordingly, there is no variation in the direction in which the air is blown out by the holes, and no horizontal component is generated in the dynamic pressure component of the blown air. As a result, the work W is levitated and supported in a well-balanced manner without receiving a conveying force in any direction. According to such a floating support, the work does not come into contact with the transport mechanism or the like, so that its cleanness is maintained.

The air that floats and supports the work in this way is:
As shown in FIG. 2, the air flows on the conveying surface 12 a, is sent out from the periphery of the work to the return duct 47 at the upper portion thereof, passes through the upper space of the casing 6, and is sucked into the blower 41 again from the air inlet 48. When the work entrance / exit portion to the space on the transport surface 12a is open without being closed by a shutter or the like, a part of the air leaks to the outside. At that time, the insufficient air during circulation is supplied from the outside air inlet 42. Since at least most of the air is circulated and used in this device, the heater output is reduced and energy is saved. In addition, the cleanliness of the air is increased by repeatedly passing through the high-performance filter, and the work has a high level of cleanliness. Is achieved. Further, a large amount of air can be easily supplied by such air circulation.

In the apparatus shown in FIG. 2, while the workpieces are taken in and out one by one on the transfer surface 12a, two workpieces are floated and supported, and are heated and heated by the floating air.
When the heat treatment of the work on the front end side is completed, the solenoid valve 53 is opened, and the suction filter 5 is sequentially moved from the compressed air introduction pipe 51a.
2, solenoid valve 53, outside air heater 54, clean filter 5
5. Compressed air is blown from the inclined nozzle 2 through the air supply communication pipe 21 and the like, and a propulsive force is given to the work.

FIG. 4 shows a state in which the work is conveyed by applying a propulsive force to the work. When the work W is centered and conveyed as shown in the plane state of (a), the distance between both ends thereof and the guide portion 3 is c, and the work W moves straight under the conveying force T in this state. .
When the workpiece W for some reason as (b) is a changed interval at both ends biased only slightly [delta] _1, less increasingly outflow air of the work under over a wide side of the interval in a narrow side, in which Accordingly, the pressure under the work becomes smaller on the wide side and becomes larger on the narrow side, and the work W is slightly inclined as shown in FIG. As a result, a horizontal component force Fx is generated in the levitation force F acting on the work W, and the side with a large gap with the guide portion 3 is lowered, so that the air under the work becomes difficult to escape, and the pressure on that side is restored to P. Thus, the workpiece moves and rotates in a direction in which the bias and the inclination are corrected. And the distance between both ends and the flying height are the same,
It is centered again and the horizontal floating state is maintained.

In the above description, when the guide portion 3 is not provided, or when the distance between both ends of the work and the guide portion is freely widened without being set, the above-described centering action does not occur. That is, when the guide portion 3 is not provided, there is no force to correct the work when the work is biased in the horizontal state. Further, when the distance between the work and the guide portion is large, the centering action does not occur until the distance becomes narrow, so that the work is moved laterally (SWAY) or swung (YAW).
Cannot be effectively regulated at an early stage. As a result, when the work approaches the guide portion, the inertial force due to the movement is large, and the correction force is relatively small, so that the movement of the work cannot be sufficiently regulated, and the work hits the guide portion. By setting the interval c to an appropriate value as in this example, the work can be conveyed while being constantly centered, contact between the work and the guide can be prevented, and clean conveyance can be ensured.

When the first work is heat-treated and sent to another floating / transporting system outside, the second work which has been similarly levitated and conveyed is stopped by a not-shown advancing / retreating stopper or the like, and a new work is newly started. The work is carried in. This work is also stopped at a predetermined position by a similar stopper or the like. In this way, the workpieces are heat-treated one by one. Note that the stopper or the like only stops the work, and does not slide in contact with only a very small part of the work, so that the cleanness of the work is not impaired.

In such an air levitation apparatus, the transport speed can be changed as needed. At that time, the transport speed can be adjusted by changing the flow rate and pressure of the propulsion air. In the deceleration and stop sections, the nozzle tilt angle is approached vertically or turned in the opposite direction, and an appropriate number of suction holes for partially inhaling the blown air are arranged in a different pitch arrangement from the air supply holes 11 to support the floating. A method of applying a suction force to the worked workpiece to perform a braking and stopping action, or the like can be appropriately adopted.

FIG. 5 shows a schematic configuration of a multi-stage heat treatment apparatus using the floating transfer plate shown in FIGS. 1 and 2 and a work floating transfer device provided with the plate. This apparatus includes an entrance elevator section 100, a heat treatment section 200, and an exit elevator section 3
00 and the like. The heat treatment section 200 is constituted by, for example, about 10 stages as the workpiece floating transfer devices 100-1 to 100-N shown in FIG. The entrance and exit elevator sections 100 and 300 are each one stage of the work levitation device 100.
Although not shown, it is configured to be able to move up and down and stop at a predetermined position by ordinary various lifting mechanisms such as a lifting guide and a lifting drive (not shown).

In this apparatus, similarly to the apparatus shown in FIG. 2, the two workpieces are heat-treated in the heat treatment section, and when the workpieces in each stage complete the heat treatment sequentially, the transfer devices in the entrance and exit elevator sections are moved to that position. It moves, and a work is taken in and out of these, and is exchanged with an external conveyance process. Also in this apparatus, each part of 100 to 300 is maintained in a state of high cleanliness. Further, as described above, since the floating transport plate has a sheet metal thin plate structure and is sufficiently lightweight, even with such a multi-stage apparatus, it is possible to satisfy the load limitation of the floor grating in a clean room or the like.

In the above description, the case where the floating transfer plate and the work floating transfer device are mainly heat treatment devices has been described. However, various devices such as a preheating device, a cooling device, and a cooling device, and a production process of an LCD glass substrate, etc. It can be used as a connection device between various devices and various devices for cleanly transporting a planar work.

When the work is not transported, the work is positioned in a floating state to facilitate positioning. In this case, since there is no sliding between the work and the support pins at the time of positioning, problems such as rubbing of the liquid crystal surface are solved.
Therefore, the floating transport plate is effectively used as a work positioning device. In the above description, an example in which the work is transported cleanly in the air has been described.However, the present invention may be applied to various devices that levitate or transport the workpiece in an inert gas atmosphere such as nitrogen gas. it can.

[0032]

As described above, according to the present invention, according to the first aspect of the present invention, the work floating structure is a thin plate-shaped upper plate having a floating surface formed with a box-shaped body. Since it is composed of a reinforcing plate that has an end face that is processed and joined to the upper plate and that reinforces the upper plate, the end surface of the reinforcing plate is usually manufactured with high precision by laser processing or sheet metal processing, so this By arranging at appropriate intervals, the surface accuracy of the upper plate of the box-shaped body, that is, the air bearing surface can be improved by utilizing the end surface accuracy of the reinforcing plate. As a result, even when a work such as an extremely large LCD glass substrate of about 1 m square is floated on a flat floating surface, it is possible to easily obtain the required planar accuracy as the upper plate constituting the floating surface. it can. And, since the reinforcing structure using the reinforcing plate is used in this manner, the box-shaped body provided with the upper plate has sufficient strength, and even in a large size, the thickness of the box-shaped body is made sufficiently thin to reduce the weight. Reduction and cost reduction can be achieved.

When the air bearing surface is formed into a concave curved surface having an arc-shaped cross section, for example, the end surface can be processed to a high-precision curvature by laser processing or the like. It can be formed well.

Further, since the upper plate is thin, a plurality of holes for blowing gas can be easily formed. In this case, if the gas supplied to the inside of the box-shaped body has a slight pressure, the gas can be blown in a direction perpendicular to the upper plate without being affected by the processing accuracy of the hole. As a result, only the floating force is applied to the work, and the work can be stably supported by the floating.

According to the second aspect of the present invention, since a nozzle for blowing gas is provided in the transport direction so as to transport the workpiece, the workpiece can be transported in a clean state. And in this case, since the work floating structure is lightweight, it is used in a multi-stage highly integrated process device such as a heat treatment device, for example, while satisfying the load resistance limit in a device installation place such as a clean room. Processing efficiency can be improved.

[Brief description of the drawings]

1A and 1B show a configuration example of a floating transport plate to which the present invention is applied, wherein FIG. 1A is a longitudinal sectional view showing the entire structure, and FIG. 1B is a partial sectional view taken along line AA of FIG.

FIG. 2 is a perspective view of a heat-treating work floating apparatus using the above-described floating transfer plate.

FIGS. 3A and 3B are explanatory views of a floating state of a work.

FIGS. 4A to 4C are explanatory diagrams of a centering operation of a work.

5A and 5B show a heat treatment apparatus in which the apparatus of FIG. 2 is configured in multiple stages, wherein FIG. 5A is a front view and FIG. 5B is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Box-shaped body 2 Inclined nozzle (nozzle part) 11 Air supply hole (a plurality of holes) 12 Upper plate 12a Transport surface (floating surface) 13 Rib (reinforcement plate) 13a End surface W Work

Claims (2)

[Claims] 1. A work floating structure for floating a flat work with gas blown from a floating surface, wherein the floating surface is formed by a thin plate-shaped upper plate having a plurality of holes through which the gas is blown. A box-shaped body that is formed and receives the internal pressure when the gas is introduced, and an end face that is processed to form the shape of the air bearing surface and that is joined to the upper plate, and the upper plate deforms when subjected to the internal pressure And a reinforcing plate that reinforces the upper plate such that the upper limit is restricted. 2. The structure for floating a work according to claim 1, further comprising a nozzle portion for blowing out gas directed in a conveying direction so as to be able to convey the work.