JPH10181871A - Automatically guided vehicle with clean unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the intrusion of particles into an automatically guided vehicle, which is adapted to travel through clean rooms of various cleanliness, through the gap around its door and clean unit while the vehicle travels through a clean room of lowered cleanliness. SOLUTION: An automatically guided vehicle 5 is provided with a first reader means 1 constituted of a light-receiving element. A clean room has in its wall near the doorway a first display means 3 constituted of a reflecting plate indicative of a change in cleanliness thereabout. Upon detecting that there will be a change in cleanliness, the automatically guided vehicle 5 decreases the rotating speed of a fan 7 in its clean unit 6 to suppress the intrusion of particles thereinto through the gap around its door while traveling through a clean room of lowered cleanliness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle that carries members in the middle of a process for performing work in a clean room and moves between a plurality of clean rooms having different degrees of cleanliness. The present invention relates to an automatic guided vehicle carrying a clean unit capable of maintaining a clean state.

[0002]

2. Description of the Related Art The classification of clean room cleanliness is defined by the particle size of fine dust and dust particles floating in the air and the number of such particles in the air per unit cubic. specific to the at how many pieces in one cubic foot 0.5μm particles, one / ft case is "class 1" of ^3, in the case of 10 / ft ³ is "class 10", 100
Pcs / ft ³ is “Class 100”, 1000 pcs / ft
In the case of t ³ is "Class 1000", 10000 / ft
^In the case of No. ³ , the English unit of "class 10000" is used, but recently, the notation of M1.5 (Class 1 of English unit) and M2.5 (Class 10 of English unit) by the metric system is also used.

As described above, the formal definition is the number of 0.5 μm particles per cubic foot, but for practical convenience, the cleanliness corresponding to the 0.1 μm particles is classified into class 1 and 0. A class 10 cleanliness corresponding to 3 μm particles is also used.

[0004] In an automatic guided vehicle that moves back and forth between a plurality of clean rooms with different degrees of cleanliness, a clean unit is loaded so that particles can be prevented from adhering even in a place where the degree of cleanliness is low during the transfer, and the original cleanliness is maintained. I can do it.

[0005]

In the conventional automatic guided vehicle 15 shown in FIG. 6, a clean unit 6 is loaded on the automatic guided vehicle 15, and a wafer cassette 9 is stored in the clean unit 6. It has become.

When the automatic transfer vehicle 15 transfers the wafer cassette 9, the shutter-like opening / closing door 11 is wound up and opened, and the transfer robot 12 transfers the wafer cassette 9 between the process apparatus and the automatic transfer vehicle 15. 9 is performed, and when the transfer is completed, the opening / closing door is closed, and the air in the clean unit 6 is filtered by the filter 8 while being circulated by the fan 7, so that the cleanness is maintained.

FIG. 7 illustrates the flow of the air in the above case. The air accelerated by the fan 7 is filtered through the filter 8 and passes around the wafer cassette 9 and then the duct It is circulated along the route of being sucked into 10 and returning to the fan 7 again.

At this time, a part of the air is taken in from the outside, and the surplus part of the air is
Is discharged to the floor surface through the inside of the device and is sucked into the filter system of the clean room by the down flow of the clean room.

The open / close door 11 provided in the clean unit 6 is not a well-sealed door, but is generally a shutter type door, a one-sided door or a double door, and a packing for filling a gap with the clean unit. Are not used to reduce the generation of particles.

Therefore, as shown in FIG. 8, air enters and exits from the gap between the clean unit 6 and the door 11, and the pressure of the air is increased by the fan 7 in the upper part of the door 11. Therefore, air leaks from the gap of the door 11, and conversely, air is sucked by the duct 10 in the lower part of the door 11, so that the pressure of the air becomes negative pressure, Will enter.

Such a situation is not a problem while passing through a clean room having a high degree of cleanliness. However, when going from a clean room having a clean degree of "class 1" to a clean room having a clean degree of "class 1000" or "class 10000". In consideration of the above, the air leaking from the gap of the door 11 has a clean degree of “class 1”, while the air entering through the gap of the door 11 has a clean degree of “class 1000” or “class 10000”. The difference is 1000 times or 10000 times, and since there is a down flow in the clean unit 6, the clean degree around the wafer cassette loaded on the lower side is considerably increased although the clean degree is not maintained as it is. It is considered that the deterioration worsens and the attachment of particles to the wafer cassette proceeds.

Further, since the filter in the clean unit 6 is compatible with "class 1", a very fine filter is used. In this manner, when air of "class 1000" or "class 10000" enters, Clogging of the filter proceeds very quickly, deteriorating the function of the filter, shortening the replacement time, and necessitating frequent replacement.

[0013]

SUMMARY OF THE INVENTION According to the present invention, as described in the claims, in an automatic guided vehicle that carries a clean unit and moves between clean rooms having different cleanness levels, the clean rooms have different cleanness levels. Based on the information from the notifying unit that informs the boundary, based on the identification result of the difference in cleanliness due to movement between clean rooms, based on the identification result by the identifying unit, when switching from high cleanness to low cleanliness, In order to reduce the speed of the fan of the clean unit and to increase the speed of the fan of the clean unit when switching from a low clean level to a high clean level, fan speed control means is provided. We were able to.

The display means for indicating the cleanliness installed at the entrance between the clean rooms may be made by binary coding, and in the embodiment of the present invention, it is sufficient that the two kinds of cleanliness classification can be recognized. It is possible to implement the present invention even with one bit, but since there is no possibility of accidental reading error due to a light source or the possibility of control in two or more types of cleanness, coding of three bits is possible. Embodiments provided with various means are also described.

When the automatic guided vehicle according to the present invention reads the display means installed on the wall when passing through the entrance of the clean room, it is determined that the automatic guided vehicle moves to a clean room having a different degree of cleanliness. If you start from a clean room with a high degree of cleanliness, you will move from a clean room with a high degree of cleanness to a low clean room, so the amount of air flowing out or in from the gap between the open and closed doors of the loaded clean unit will be reduced, and most of the fan generated Reduce the fan airflow so that the airflow is used for circulation inside the clean unit.

By completely stopping the fan, it is possible to prevent the outflow or inflow due to the wind pressure generated by the fan inside the clean unit from the gap between the opening and closing doors of the clean unit, but the downflow of the clean room outside the clean unit is prevented. When there is wind pressure, the downflow inside the clean unit becomes zero, so air with poor cleanness due to external wind pressure may flow in, and in that case, particles that have accumulated inside the clean unit are also wound up It is unlikely that shutting down the fan inside the clean unit completely would be a good idea.

When the automatic guided vehicle according to the present invention reads the display means installed on the wall in the opposite direction when passing through the entrance of the clean room, the vehicle moves from a clean room having a poor cleanness to a good clean room. Therefore, the wind flowing out or in through the gap between the open and closed doors of the loaded clean unit and the surrounding cleanliness level become the same, and it is not necessary to consider the outflow or inflow through the gap in the open and close doors. "Increase the airflow of the fan to maintain a sufficient cleanliness in the clean room.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, and
Is the case where the vehicle is traveling from "class 1" to the entrance of the "class 1000" or "class 10000" clean room.

The fan 7 in the clean unit 6 supplies a sufficient amount of air to perform a sufficient operation in a "class 1" clean room. On a wall near the entrance of the clean room, a first display unit constituted by a reflection plate indicating a boundary of a “class 1” clean room is provided.

A first reading means 1 constituted by a light receiving element is provided on a side of the automatic guided vehicle 5 opposite to the reflection plate, and is provided with light for illuminating a clean room or a dedicated light source. Can read the light reflected by the reflection plate.

Here, as the automatic guided vehicle 5 travels, the light receiving element installed on the side surface of the automatic guided vehicle 5 is placed beside the reflecting plate as the first display means installed on the wall near the entrance of the clean room. Is read, the display content of the first display means is a "class 1" clean room.

According to the result of reading by the light receiving element (first reading means 1) of the automatic guided vehicle 5, the "class 1000" or "class 1000"
0 ", the speed of the fan in the clean unit is reduced by a speed variable means (not shown), and the outflow or inflow of air from the gap between the clean unit 6 and the door 11 is reduced. It is possible to prevent the deterioration of the cleanness inside the clean unit.

Conversely, when the automatic guided vehicle 5 enters the "class 1" clean room from the "class 1000" or "class 10000" clean room by using the display means and the reading means shown in FIG. become.

The speed of the fan 7 in the clean unit 6 is increased so that the "class 1" cleanness can be maintained in the clean unit 6. In this case, the automatic guided vehicle 5
When the light receiving element installed on the side surface of the automatic guided vehicle 5 passes along the reflector, which is the first display means installed on the wall near the entrance and exit of the clean room, the first display means Is read as "class 1".

From the result of reading by the light receiving element (first reading means 1) of the automatic guided vehicle 5, it is determined that the user has moved from the "class 1000" or "class 10000" clean room to the "class 1" clean room. Therefore, the speed of the fan in the clean unit can be increased by a speed variable means (not shown), so that a sufficient air volume can be obtained in a “class 1” clean room.

FIG. 2 shows a second embodiment of the present invention.
The display means and the reading means are changed from 1 bit to 3 bits to eliminate a reading error. FIG. 3 shows a third embodiment of the present invention. A first display means comprising a combination of reflectors indicating that the room is a "class 1" clean room is provided on the wall near the entrance and exit of the clean room, The second display means composed of a combination of reflectors that indicate that the outside of the clean room outside the entrance / exit is a “class 1000” or “class 10000” clean room is perpendicular to the traveling direction of the automatic guided vehicle 5 as described above. They are arranged in order.

A first reading means 31 constituted by a light receiving element is provided on a side of the automatic guided vehicle 5 which faces the reflection plate, and is provided with light such as illumination light for a clean room or a dedicated light source. Can read the light reflected by the reflection plate.

Here, as the automatic guided vehicle 5 travels, the light receiving element installed on the side surface of the automatic guided vehicle 5 is replaced with the first display means 33 installed on the wall near the entrance of the clean room.
When passing through the side of the reflecting plate, the first display means 33 reads that the display content is a "class 1" clean room, and then similarly displays the second display installed on the wall near the entrance and exit of the clean room. It reads that the display content of the means 34 is “class 1000” or “class 10000”.

Conversely, using the display means 33 and 34 and the reading means 31 shown in FIG.
When entering a “class 1” clean room from a “0” or “class 10000” clean room, the operation is as follows.

In this case, as the automatic guided vehicle 5 travels,
When the first reading means 31 constituted by the light receiving elements provided on the side surface of the automatic guided vehicle 5 passes beside a reflecting plate which is the second display means 34 provided on the wall near the entrance of the clean room. It is read that the display content of the second display means 34 is a "class 1000" or "class 10000" clean room, and then the display content of the first display means 33 similarly installed on the wall near the entrance and exit of the clean room. Is read as "class 1".

According to the result of reading by the light receiving element (first reading means 31) of the automatic guided vehicle 5, it has been moved from the "class 1000" or "class 10000" clean room to the "class 1" clean room. Therefore, the speed of the fan in the clean unit can be increased by a speed variable means (not shown), so that a sufficient air volume can be obtained in a “class 1” clean room.

FIG. 4 shows a fourth embodiment of the present invention, in which a first display means 43 constituted by a combination of reflectors indicating that the room is a "class 1" clean room is provided on the wall near the entrance and exit of the clean room. Only have been installed.

On the side of the automatic guided vehicle 5 facing the reflection plate, in addition to the first reading means 41 comprising a light receiving element similar to that of the first embodiment, in addition to the first reading means 41, the traveling direction of the automatic guided vehicle 5 The second reading means 4, which is composed of a light receiving element similar to the first reading means 41, and which is vertical and parallel to the first reading means 41.
2 are installed.

Here, as the automatic guided vehicle 5 travels, the first reading means 41 composed of a light receiving element installed on the side surface of the automatic guided vehicle 5 is provided with a reflecting plate installed on the wall near the entrance of the clean room. First display means 4 composed of a combination
3 that the display content of the first display means 43 is a "class 1" clean room when passing by
Thereafter, similarly, the second reading means 42 reads that the display content of the first display means 43 is a "class 1" clean room.

From the results of reading by the first reading means 41 and the second reading means 42, which are composed of light receiving elements of the automatic guided vehicle 5, transfer from the current "class 1" clean room to a clean room with a low degree of cleanliness ( In the case of the present embodiment, it can be seen that a “class 1000” or “class 10000” clean room is performed.

Conversely, using the display means 43 and the reading means 41 and 42 shown in FIG.
When entering a “class 1” clean room from a “0” or “class 10000” clean room, the operation is as follows.

In this case, as the automatic guided vehicle 5 travels,
A second light receiving element installed on the side of the automatic guided vehicle 5
When the reading means 42 passes by the first display means 43 composed of a combination of reflectors installed on the wall near the entrance and exit of the clean room, the display content of the first display means 43 is "class 1". The first reading means 41 reads that the room is a clean room, and then the first reading means 41 similarly reads that the display content of the first display means 43 is a "class 1" clean room.

The result of reading by the second reading means 42 and the first reading means 41 comprising the light receiving elements of the automatic guided vehicle 5 indicates that the current clean room is low in cleanliness (in this embodiment, "Class 1000"). Or "Class 1000
0) to the "class 1" clean room, the speed of the fan 7 in the clean unit 6 is increased by a speed variable means (not shown) to move the "class 1" clean room. A sufficient air volume can be obtained in a clean room.

FIG. 5 shows that the automatic guided vehicle 5 moves from a “class 1” clean room to a “class 10” through a “class 1000” or “class 10000” communication passage.
"0" indicates the case of moving to a clean room.

The automatic guided vehicle 5 reads the sign at the entrance of the “Class 1” clean room on the third floor of the building A, reduces the wind speed of the fan 7 of the clean unit 6 to allow outflow of air to the outside and air from the outside. Enter elevator A and go down to the first floor. The unmanned guided vehicle 5 descending to the first floor is “Class 1000” or “Class 100”.
Via the communication passage of "00", take the elevator B of the building B, and enter the "class 100" clean room on the fourth floor of the building B.

Here, in this embodiment, the wind speed of the fan 7 of the clean unit 6 is controlled in two stages according to the classification by dividing the class into "class 1" and the other classes of cleanness. When entering a “class 100” clean room, the fan 7 of the clean unit 6 is not particularly controlled. For example, if the fourth floor of the building B is a “class 1” clean room, the same display as that of the building A is performed. The air volume of the fan 7 can be increased again.

With the combination of the above-described reflector and light receiving element, it is conceivable that a sufficient detection result of the light receiving element may not be obtained depending on the lighting conditions of the clean room. By providing means,
More reliable detection results can be obtained.

When a sufficient detection result of the light receiving element cannot be obtained in the same manner as described above, a more reliable detection result can be obtained by displaying the degree of cleanness of the clean room by using the reflector as a light emitting element and combining them.

Also, the code of the cleanliness is transmitted by a radio transmitter such as a weak radio wave instead of the reflector, and the code is received by the receiver instead of the light receiving element to detect the cleanliness. The effect is obtained.

Further, although not shown, a storage means of the current cleanliness is provided in the automatic guided vehicle 5, and only one set of reading means including light receiving elements installed in the automatic guided vehicle 5 is used. Even when there is only one display unit composed of a combination of reflectors installed on the wall surface near the entrance, it is possible to determine that the current cleanliness level is changed based on the detection result of the light receiving element. can get.

[0046]

As described above, according to the present invention, when the cleanness of the clean room in the moving direction of the automatic guided vehicle is lower than the current cleanness, the air volume of the fan of the loaded clean unit is reduced. So, while moving the automatic guided vehicle, "Class 1000" or "Class 10000"
When passing through the clean room, the intrusion of particles into the clean unit can be reduced, and as a result, the adhesion of particles to the loaded wafer cassette and the like can be reduced.

Also, by reducing the intrusion of particles into the clean unit, clogging of the filter is reduced,
Since the filter replacement time can be delayed, it is economically advantageous.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a moving path of the automatic guided vehicle and an installation position of an optical display unit according to the present invention.

FIG. 6 is a diagram showing a configuration of a conventional technique.

FIG. 7 is a first diagram showing the flow of air in the related art.

FIG. 8 is a second diagram showing the flow of air in the related art.

[Explanation of symbols]

 1, 21, 31, 41 First reading means 42 Second reading means 3, 23, 33, 43 First display means 34 Second display means 5, 15 Automatic guided vehicle 6 Clean unit 7 Fan 8 Filter 9 Wafer cassette 10 Duct 11 Opening / closing door 12 Transfer robot

Claims (6)

[Claims] 1. An automatic guided vehicle running between a plurality of clean rooms having different cleanliness, on which a clean unit is loaded, wherein the identification means provided on the automatic guided vehicle identifies a difference in the cleanliness of the surrounding area when moving. A method of controlling a fan speed that varies the speed of a fan that circulates air in a clean unit according to the identification result. 2. An automatic guided vehicle that carries a clean unit and moves between clean rooms having different cleanness levels. An identification means for identifying a difference in cleanliness caused by movement between clean rooms, and an identification result based on the identification result by the identification means. Fan speed control means for lowering the speed of the clean unit fan when switching from high cleanness to low cleanness, and increasing the speed of the clean unit fan when switching from low cleanness to high cleanness; An automatic guided vehicle for a clean room, comprising: 3. The reading means is a reading means which is provided at an entrance of a clean room having a different degree of cleanness and optically reads a display means for notifying a boundary of the different degree of cleanness by a display pattern. Identifying that the degree of cleanness changes based on the content, the fan speed control means, when the speed of the fan is high, if the reading means reads a display pattern, reduces the speed of the fan, the fan speed 3. The automatic guided vehicle for a clean room according to claim 2, wherein the speed of the fan is increased when the reading unit reads the display pattern at a low speed. 4. The display means displays a first display pattern indicating a high degree of cleanliness and a second display pattern indicating a low degree of cleanliness in the order of the cleanliness of the cleanroom at the entrance of the clean room having the different degree of cleanliness. The identification unit is a reading unit that optically reads the first and second display patterns, and the identification unit is a reading unit that optically reads the first and second display patterns. The fan speed control means reduces the fan speed when the reading means reads the first display pattern first, and the reading means 4. The automatic guided vehicle for a clean room according to claim 3, wherein the speed of the fan is increased when the second display pattern is read first. 5. The identification means is a reading means for optically reading the display means, is installed at two places of an automatic guided vehicle for a clean room, and a second reading means reads the display means after reading the display means. The first reading means reads the display means when the reading means reads the display means and the first reading means after the second reading means reads the display means.
Identifying the case where the reading means has read the display means, identifying the difference in the degree of cleanliness based on which of the first and second reading means has read the display means first, the fan speed control means If the first reading means reads the display means first, the speed of the fan is reduced, and if the second reading means reads the display means first, the speed of the fan is increased. The automatic guided vehicle for a clean room according to claim 3, wherein: 6. The identification means is reading means for optically reading the display means, and the automatic guided vehicle is provided with a storage means for storing a degree of cleanliness of a place where the automatic guided vehicle is currently located, When the content stored in the storage means has a high degree of cleanness and the reading means has read the display means, the content stored in the storage means is changed to the content of a low cleanness level, and the speed variable means is used. By lowering the speed of the fan, the content stored in the storage means has a low cleanness, and when the reading means has read the instruction means, the storage content of the storage means is replaced with the storage content of the high cleanness. 4. The automatic guided vehicle for a clean room according to claim 3, wherein the speed of the fan is increased by the variable speed means.