JP2005075497A - Levitation conveyance device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of conveying a large and thin-walled liquid crystal substrate by levitation by air without straying off a conveyance passage, coming into contact with the surroundings, and being damaged. <P>SOLUTION: Blow-out ports for propulsion are provided in at least three rows at the center of the conveyance passage along the direction of width of the conveyance passage, and propulsion force from the blow-out port in a central part is set to be larger than propulsion force from the blow-out ports on both left and right sides. Direction of conveyance object and position in the direction of width for the conveyance passage can be stably kept to convey it securely by levitation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for transporting a transported object such as a liquid crystal substrate by levitating it with air.

  With the increase in size of liquid crystal glass substrates and the like, it has become impossible to carry the conventional cassette unit. For example, if the substrate size is 2 m × 2 m, the cassette handling the robot and the robot hand need to have a size of 2 m × 2 m or more, and the transfer equipment becomes huge due to the increase in size and the weight of the cassette.

  As a transfer device that does not use a cassette, a floating transfer device using air can be considered. In the levitation transport device, high-pressure air is generated by a compressor, stored in a tank, and lifted from a plurality of nozzles toward the bottom surface of the transported object to float the article. By the way, the liquid crystal substrate to be transported is a thin and large substrate and is easily damaged when the substrate deviates from the transport path and comes into contact with the surroundings.

A basic problem of the present invention is to stably maintain the direction of the conveyed product and the position in the width direction with respect to the conveyance path.
An additional problem in the invention of claim 2 is to further stabilize the direction of the conveyed product and the position in the width direction.
An additional problem in the invention of claim 3 is to make the conveyed product float more reliably and to keep the direction and position of the conveyed product more stable.

  The present invention is a levitation transport apparatus configured to transport a transported object by ejecting gas obliquely upward in the transport direction so that the transported object is transported at least 3 along the width direction of the transport path. Provided in a row, the propulsive force from the central outlet is larger than the propulsive force from the outlets on both sides.

  Preferably, a blowing outlet for guidance is provided at both ends in the width direction of the transport path to eject gas toward the center in the width direction of the transport path.

  Preferably, a levitation blow-out port for blowing gas directly above is provided between the propulsion blow-out port and the guide blow-out port.

  In the present invention, a gas having a high driving force is blown to the central portion in the width direction of the conveyed product, and a gas having a lower driving force than that of the central portion is blown to both sides thereof. For this reason, even if there is a difference in propulsive force between the outlets on both sides, the moment for changing the direction of the conveyed product can be reduced, and the direction of the conveyed product and the position in the width direction can be easily maintained stably. If the direction of the conveyed product and the position in the width direction can be stabilized, the conveyed product can be prevented from protruding from the conveying path and being damaged. The orientation and position of the conveyed product are referred to as a posture, and correcting these to a predetermined position and orientation is referred to as centering.

  In the invention of claim 2, since the guide outlets for blowing out the gas toward the inside of the transport path are provided at both ends in the width direction of the transport path, if the direction of the transported object or the position in the width direction is out of order, The direction and position are corrected with the gas from the air outlet, so that it can be transported more stably.

  In the third aspect of the present invention, the floating outlets for blowing out the gas immediately above are arranged on both sides of the outlet for propulsion. When gas is blown obliquely upward for propulsion at this position, even if there is a slight imbalance on both sides in the width direction, a large moment acts on the conveyed product, but since the gas is blown directly above, articles can be conveyed more stably. .

  In the following, an optimum embodiment for carrying out the present invention will be shown.

Best practice

  1 to 5 show an optimum embodiment using a fan or a blower. FIG. 1 shows an example of the levitation unit 2 and the propulsion unit 4, both of which have a built-in fan 10, and blowout ports 8 and 9 are formed in the upper portions of the casings 6 and 7. In the case of the levitation unit 2, the air blowing direction is, for example, directly above. In the case of the propulsion unit 4, the air blowing direction is obliquely upward, and the louvers 12 and 13 are attached for that purpose.

  The units 2 and 4 are provided with a fan 10, except for adjusting the blowing direction by the louvers 12 and 13, so that the air supply from the fan 10 reaches the blowing ports 8 and 9 straightly, There is no bend (vent) of the air supply path between the fans 10. As a result, there is almost no pressure loss from the outlet of the fan 10 other than that due to the louvers 12 and 13. Further, for example, one fan 10 is provided for each of the units 2 and 4, and the air volume can be controlled independently. The air to be supplied is that the lower air of the units 2 and 4 is sent upward by the fan 10, so that piping, a compressor, a high-pressure air tank, a nozzle, and the like are not required.

  The fan 10 is an axial fan here, and its output is 0.1 atm or less (10 KPa or less) in terms of wind pressure, and a blower having a wind pressure of 0.2 atm or less may be used instead of the fan, but it is inexpensive. A fan with low energy required for operation is preferable. The surface size of the units 2 and 4 is, for example, about 5 cm × 5 cm to 20 cm × 20 cm on one side, and in the embodiment, the surface has a substantially square shape of about 10 cm square, and the height is set to install the louvers 12 and 13. The required height + the thickness of the fan 10. The glass for a liquid crystal substrate, which is a conveyed product, is, for example, a rectangular shape having a side of about 1 to 2 m and a mass of about 10 kg, along the left-right direction of the conveyance path (the direction perpendicular to the conveyance direction and the horizontal plane) There are 5 to 40 units 2 and 4 arranged. These units include propulsion, levitation, and centering types, and the unit fan is turned on / off and the air volume is controlled according to the position of the board. This makes it possible to finely control the posture and speed of the conveyed product.

  FIG. 2 shows a modified fan unit 20, 22 is a movable louver whose direction can be changed by an actuator (not shown), and along with this, air is sent directly above to act as a levitation unit, It can be operated as a unit for propulsion or stop by supplying air obliquely forward or diagonally backward.

  The units 2, 4 and the like are arranged in a straight line along the transport direction, but are arranged alternately, for example, in a direction perpendicular to the transport direction, and arranged in a staggered manner as a whole. The units 2 and 4 as a whole may be arranged in a lattice pattern, and the units 2 and 4 may be staggered by arranging the units 2 and propulsion units 4 alternately. A gap between the rows of units parallel to the transport direction becomes the guide passage 15, and when the substrate is guided by a guide (not shown) or the like, the guide is moved along the guide passage 15. The gap 16 is a gap for facilitating the installation and maintenance of the units 2 and 4 and may not be provided. The bottom surfaces of the guide passage 15 and the gap 16 may be closed so that the air blown out from the units 2 and 4 does not escape. Alternatively, the bottom of the guide passage 15 and the gap 16 is not blocked, the air blown out from the units 2 and 4 is collected from this portion, returned to the fan unit (not shown), and supplied again, and the air used for levitation is circulated. You may make it not escape outside.

  FIG. 3 shows the arrangement of units in the left-right direction of the transport path 30. A high speed propulsion unit 32 is provided at the center of the conveyance path 30, and for example, low speed propulsion units 33, 33 are provided on both sides thereof. The total of the propulsion units 32 and 33 is three rows here, but may be one row or five rows. When three or more rows are provided, for example, about 1-3 rows of high-speed propulsion units 32 are provided at the center, and about 1-3 rows of low-speed propulsion units 33 are provided on both sides thereof. A plurality of levitation units 34 are provided on both outer sides of the low-speed propulsion unit 33, air is sent directly above to float the conveyed product, and centering units 36, 36 are provided on both outer sides thereof, and the air is conveyed through the conveyance path. 30 is blown out obliquely upward inside. A row of levitation units 34 may be arranged between the row of high-speed propulsion units 32 and the row of low-speed propulsion units 33. The levitation unit 34 may be mixed in the row. Further, the centering units 36 and 36 are always arranged so as to be on the outer side in the left-right direction with respect to the conveyed product 40. Reference numeral 38 denotes a guide, which is provided with a cushion material or the like on the surface on the conveyance path 30 side, and prevents a conveyed product from protruding from the conveyance path 30. If a bar-shaped guide 39 or the like is provided in place of the plate-shaped guide 38 and a cushion material is wound around the surface of the guide, it is possible to eliminate the possibility that the corner of the conveyed object hits the guide 38 having no gap and is damaged.

  FIG. 4 shows a correction mechanism for the position and orientation of the conveyed product 40 in the left-right direction. Keeping the right and left position correct and keeping the direction of the conveyed product correct is called centering. It is assumed that the state of the conveyed product 40 shown by the solid line in FIG. 4 is a normal state, for example, the direction has changed from now on to become a chain line. Then, the right side of the conveyed product 40 receives air supply from the centering unit toward the inside of the conveyance path, and the change in posture is corrected by the moment of force caused by this. Even when the conveyed product 40 is misaligned in the left-right direction, the misalignment is similarly corrected by the centering unit.

  As shown in FIG. 3, the propulsion units are provided, for example, in three rows, and a high-speed propulsion unit 32 is provided at the center thereof. Here, if the propulsive force from each row is unbalanced in a plurality of rows of propulsion units, the transported object 40 is caused to rotate. Here, if the high-speed propulsion unit 32 is disposed in the central portion of the transport path 30 and the low-speed propulsion units 33 and 33 are disposed on both sides, the central high-speed propulsion unit 32 causes the posture of the conveyed product 40 to change. Since it is difficult, the change of the posture of the conveyed product 40 by the propulsion unit can be prevented. If the propulsive force is not uniform between the left and right low-speed propulsion units 33, 33, the posture of the conveyed product 40 changes, but the influence is relatively small because of the low speed.

  FIG. 5 shows the layout of the levitation transport device. Here, the transported object transported upward from the bottom of the figure by the transport unit 41 is transported from the left to the right by the transport unit 43 by changing the transport direction by the transport unit 42, and turned again by the transport unit 44. To the transport unit 45. 46a to 46c are propulsion units, and the low speed propulsion units are arranged on both sides of the high speed propulsion unit as described above, and 47 is a centering unit in which the centering units are arranged. Reference numeral 48 denotes a stop unit which is used to temporarily stop the conveyed product by the transport unit 42 or the transport unit 44. Each transport unit is provided with a transport object sensor 49 or the like at an appropriate position to detect the position of the transport object, and this is input to the control unit 50. Depending on the position of the transport object, the fan of each unit is detected. It floats and conveys by changing the air volume or turning the fan on / off. What is necessary is just to use what uses the difference in the dielectric constant by the presence or absence of a glass substrate, the sensor which detects the reflection of the ultrasonic wave by a glass substrate, etc. for the conveyed product sensor 49, for example. The fans of each unit can be controlled independently for each unit, but it is not necessary to control all the units separately. For example, the floating units arranged on the left and right at substantially the same position in the transport direction have the same timing as one group. The on / off control may be performed with

  Further, in the embodiment, the conveyance path is formed in a U-shape. However, in FIG. 5, if the conveyance object can be sent out above the conveyance unit 42 or the conveyance object 44 can be sent out to the right side of the conveyance unit 44, Can be branched. In this case, for example, if only the propulsion unit 46 a is operated without operating the propulsion unit 46 b in the transport unit 42, it branches to the upper side of the transport unit 42. Further, the propulsion unit 46a advances the conveyed product to the vicinity of the stop unit 48, then stops the propulsion unit 46a, brakes the conveyed item by the downward air supply from the stop unit 48 in FIG. When 46b is operated, the conveyance direction can be changed by 90 °. If the air supply direction of the propulsion unit is arranged in an arc shape, etc., the conveyed product can be rotated, the louver adjusts the air supply direction of the fan, and multiple units with different air supply directions are arranged. Objects can be conveyed by various routes.

  A filter unit 52 uses a clean room filter unit or the like, supplies clean air to a plurality of levitation units, a propulsion unit, a centering unit, and the like, thereby preventing contamination of the conveyed product during levitation conveyance. The filter unit 52 may not be provided. Further, the conveyed product is not limited to a glass substrate for liquid crystal.

In the embodiment, an example using a fan or a blower has been described, but a nozzle may be used as shown in FIG. In this case, a plurality of nozzles are arranged in one unit, the low-speed propulsion units 63 and 63 are arranged on both sides in the left-right direction of the row of the high-speed propulsion units 62, and a plurality of levitation units (not shown) are arranged on both outer sides. Arrange column by column. The individual nozzles are schematically shown by arrows in FIG. In the propulsion units 62 and 63, gas such as air or nitrogen is blown obliquely upward from the nozzle, and in the levitation unit, gas is blown out from the nozzle directly above. Further, on both outer sides of the row of the levitation units, units each provided with a centering nozzle are arranged at a position slightly outside the left and right ends of the conveyed object at all times (in a normal position and orientation). The modification of FIG. 6 is the same as the embodiment of FIGS. 1 to 5 except that the fan is replaced with a nozzle.

The figure which shows the unit for levitation and the unit for a propulsion in the levitation conveyance apparatus of the optimal embodiment Sectional drawing which shows the unit which made the direction of the louver variable The figure which shows arrangement | positioning of the unit to the width direction of the conveyance path in the optimal Example The figure which shows the posture correction mechanism of a conveyed product in the optimal example The figure which shows the layout of the levitation conveyance device of the optimum embodiment The principal part top view of the levitating conveyance apparatus of a modification

Explanation of symbols

2 Levitation unit 4 Propulsion unit 6, 7 Housing 8, 9 Outlet 10 Fan 12, 13 Louver 20 Fan unit 22 Movable louver 30 Transport path 32 High speed propulsion unit 33 Low speed propulsion unit 34 Levitation unit 36 Centering unit 38, 39 Guide 40 Conveyed objects 41 to 45 Conveying units 46a to 46c Propulsion unit 47 Centering unit 48 Stopping unit 49 Conveyed object sensor 50 Control unit 52 Filter unit 62 High speed propulsion unit 63 Low speed propulsion unit

Claims (3)

A levitation conveyance device configured to convey gas by ejecting gas from a blowout port obliquely upward in the conveyance direction,
The propulsion outlets for propulsion are provided in at least three rows along the width direction of the conveyance path, and the propulsive force from the central outlet is larger than the propulsive force from the outlets on both sides. , Floating transport device. The levitation conveyance apparatus according to claim 1, wherein a guide outlet for ejecting gas toward the widthwise center of the conveyance path is provided at both ends in the width direction of the conveyance path. The levitation conveying apparatus according to claim 2, wherein a levitation blowing outlet for blowing a gas directly above is provided between the propulsion blowing outlet and the guidance blowing outlet.

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