JP2534779B2 - Pressure difference control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure control device that eliminates a pressure difference between two dustproof chambers.

[Conventional technology]

FIG. 3 is a schematic cross-sectional view showing two partitioned dustproof chambers for explaining an example of a conventional pressure difference control device. Conventionally, in order to make the pressures P ₁ and P ₂ in the two dustproof chambers 1 and 2 the same, as shown in FIG. I was trying to lose the pressure difference. However, due to a difference in volume of the chambers, a difference in size of the devices arranged, and the like, a pressure difference may be generated between the two chambers, and an air flow may occur at the entrance / exit 3 of the wall 7 partitioning the two chambers as indicated by an arrow. is there. For example, when the pressure P ₁ in the dustproof chamber ₁ is higher than the pressure P _{2 in the} dustproof chamber 2, the air flow is
Flows from the dustproof chamber 2 to the dustproof chamber 1 through the doorway. if,
At this time, if the dust level in the dustproof chamber 1 is worse than that in the dustproof chamber 2, the dust will be carried by this air flow. This contaminates the semiconductor substrates stored in the storage fence 5.

As a countermeasure for this, as a pressure difference control device, for example, a blower device 4 is newly provided on the dustproof chamber 2 side on the low pressure side, and a simple pressure gauge is provided in each chamber, and the blown air amount of the blower device 4 is observed while watching this pressure gauge. Was adjusted to eliminate the pressure difference between the two chambers.

[Problems to be Solved by the Invention]

In the above-mentioned conventional pressure difference control device, since the pressure adjustment, that is, the amount of air blown by the air blower is only set first, there is a drawback that the pressure difference occurs again when an object or person in the room changes.

An object of the present invention is to eliminate such drawbacks and provide a pressure difference control device which is always stable and eliminates the pressure difference.

[Means for solving the problem]

A feature of the present invention is that one side end is attached to one side end of an opening frame that opens a wall that divides the dustproof chamber into two, and the other end and the one are provided so as to be bent toward either of the dustproof chambers depending on the wind direction. A pressure detection plate that covers the opening with a gap left between the opening, a detector that detects that the other end of the pressure detection plate is deflected toward one of the dustproof chambers, and the pressure detection plate is installed in one of the dustproof chambers. A pressure difference control device that eliminates a pressure difference between the two dustproof chambers by detecting the wind direction by the detector and operating the air blower.

〔Example〕

Next, the present invention will be described with reference to the drawings. First
FIG. 1A is a schematic cross-sectional view of two partitioned dustproof chambers for explaining the first embodiment of the pressure difference control device of the present invention,
FIG. 1 (b) is a view taken along the line AA of FIG. 1 (a), and FIG. 1 (c).
[Fig. 3] is an enlarged view of a B portion in Fig. 1 (a). This pressure difference control device, as shown in FIG. 1, has an opening frame beside a conventional entrance / exit.
3a is provided, one end of which is fixed to the upper side of the opening frame 3a, and the other end of which is free to approach either chamber side by wind pressure,
A detector composed of light projecting elements 11a, 11b and photosensors 9a, 9b for detecting whether the pressure detection plate 8 is closer to any one of the chambers, and a controller for adjusting the amount of air blown by the air blower 4 by this detector. That is to say.

Next, the operation of this pressure difference control device will be described. First,
Assuming that the pressure P _{1 in} the dust-proof chamber ₁ and the pressure P ₂ in the dust-proof chamber are P ₁ > P ₂ , the air flows from the dust-proof chamber 1 to the dust-proof chamber 1 as shown in FIGS. 2 through the opening frame 3a. At this time, the pressure detection plate 8 comes close to the right side with respect to the paper surface as shown by the dotted line. As a result, the light emitting element 11a
The emitted light is blocked, and the control circuit in the controller breaks the current balance, and the output of the blower unit 4 is increased according to the amount of this break. When the amount of air blown by the air blower 4 increases, the pressure P ₂ in the dustproof chamber ₂ rises, becomes equal to the pressure P ₁ in the dustproof chamber 1, the air does not flow, and the pressure detection plate 8 remains at the neutral position. By this,
The light emitted from the light projecting elements 11a and 11b is detected by the photosensors 9a and 9b, and the photocurrents emitted from the photosensors 9a and 9b cause the controller to operate, so that the blower unit 4 returns to the blown air volume output first. Conversely, P
_In the case of ₁ <P ₂ , air flows from the dustproof chamber 2 to the dustproof chamber 1 through the opening frame 3a. As a result, the pressure detection plate 8 is moved to the left side of the paper surface, that is, the dustproof chamber 1 side. The pressure detection plate 8 blocks the light emitted from the light projecting element 11b, the photocurrent generated from the photosensor 9b disappears, the controller is operated, and the amount of air blown by the air blower 4 is reduced. Therefore, the pressure P ₂ in the dustproof chamber ₂ is no different from the pressure P _{1 in the} dustproof chamber.

FIG. 2 is a schematic cross-sectional view showing a pressure difference control device according to the related art of the present invention. As shown in the figure, this pressure difference control device is provided with an opening frame, which is larger than the entrance 3 (at least four times as large as the area of the entrance) in addition to the entrance 3, and the opening frame 3b. Attach the rotary shaft to the upper end of
The damper T2 having a low friction bearing was attached to this rotary shaft. Thus, when the pressure P ₁ in the dustproof chamber 1 is high, the damper 12 swings to the position shown by the dotted line, and the air flows from the dustproof chamber 1 into the dustproof chamber to eliminate the pressure difference. On the contrary, when the pressure P ₂ in the dustproof chamber 2 is high, the damper 12 swings to the left side toward the paper surface, and the air moves from the dustproof chamber 2 to the dustproof chamber 1 through the gap between the opening frame 3b and the damper 12. Eliminate the flow pressure difference.
This embodiment has an advantage that an inexpensive pressure difference control device can be obtained as compared with the above-mentioned embodiments.

〔The invention's effect〕

As described above, the present invention is provided with means for detecting the pressure difference between the two chambers, and by this means, by varying the amount of air blown into either of the dust-proof chambers, two dust-proofs which are always stable and have no pressure difference are provided. The pressure difference control device for controlling the chamber can be obtained.

[Brief description of drawings]

FIG. 1 (a) is a schematic cross-sectional view showing two partitioned dustproof chambers for explaining the first embodiment of the pressure difference control device of the present invention, and FIG. 1 (b) is FIG. 1 (a). ) AA arrow view, FIG. 1 (c) is an enlarged view of part B, FIG. 2 is a schematic sectional view showing a pressure difference control device of the related art of the present invention, and FIG. 3 is a conventional pressure difference control device. It is a schematic cross section which shows two partitioned dust-proof chambers for explaining an example. 1,2 …… Dustproof room, 3 …… Entrance, 3a, 3b …… Opening frame, 4…
... Blower, 5 ... Storage rack, 6 ... Blowout port, 7 ... Partitioning wall, 8 ... Pressure detection plate, 9a, 9b ... Photo sensor, 10
...... Controller, 11a, 11b ...... Light emitting element, 12 ...... Damper.

Claims (1)

(57) [Claims] 1. A one-side end is attached to one side end of an opening frame for opening a wall that divides the dust-proof chamber into two, and the other end and the other end are bent so as to be bent toward one of the dust-proof chambers depending on the wind direction. A pressure detection plate that covers the opening with a gap left between the opening and
A detector for detecting that the other end of the pressure detection plate is bent toward one of the dust-proof chambers, and a blower installed in any of the dust-proof chambers, and the wind direction is detected by the detector. A pressure difference control device which eliminates a pressure difference between the two dustproof chambers by detecting and operating the blower.