JPH05164269A - Vacuum valve - Google Patents

Abstract

PURPOSE:To provide a vacuum valve capable of selective operation over a range from slow exhaust state to large bore exhaust state only through the introduction of the predetermined compressed gas to a single vacuum valve. CONSTITUTION:When compressed gas is introduced to space below the first piston 7, a main valve 32 slightly moves upward via the first stem 14, together with the first piston 7, thereby forming a leak opening. As a result, the air in a vacuum chamber is first drawn gradually through the leak opening, until establishing the pressure state of several meters head where no particle whirls in the predetermined time. Furthermore, the compressed gas is introduced to space below the second piston 5 in a cylinder enclosure 3, and a main valve 32 is thereby caused to quickly move upward via the first stem 14, together with the second piston 5. Consequently, a large bore main valve device for communicating a vacuum chamber 43 with a vacuum pump 40, opens and the residual air in the chamber 43 is discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve used between a vacuum chamber and a vacuum pump when the vacuum chamber is in a vacuum state.

[0002]

2. Description of the Related Art Conventionally, in order to bring a vacuum chamber used for semiconductor manufacturing or the like close to a vacuum chamber, as shown in FIG.
(01) and the vacuum pump (02) were connected by the conduit (03) and suctioned by the vacuum pump (02), but since the single vacuum valve (04) is used, the vacuum valve (04)
When opened, the vacuum chamber (01)
And the inside of the conduit (03) becomes a turbulent flow at a high pumping speed, and particles rise up.

In order to prevent this, in recent years, as shown in FIG. 5, a bypass passage (06) is provided so as to bypass the large-diameter vacuum valve (04), and the bypass passage (06) is provided.
A small-diameter vacuum valve (05) is attached to the both, and both vacuum valves are used together to perform vacuuming stepwise. That is, when the vacuum chamber (01) is evacuated, the small-diameter vacuum valve (05) is first opened, and the conduit (03) and the vacuum chamber (01) are gradually evacuated to several Torr by the vacuum pump (02). .. In a vacuum state of several torr, there is no molecular weight enough to soothe particles, and then the large-diameter vacuum valve (04) is fully opened to perform stable vacuum evacuation.

[0004]

However, the provision of both the small-diameter vacuum valve (05) and the large-diameter vacuum valve (04), which are controlled over time using the controller (07), is Not only the structure becomes complicated, but also the cost becomes expensive. An object of the present invention is to provide a vacuum valve having a very simple structure which can be operated so as to switch from slow exhaust gas to large-diameter exhaust gas by simply introducing a predetermined pressure gas into a single vacuum valve.

[0005]

The vacuum valve of the present invention comprises:
In a vacuum valve arranged between a vacuum chamber and a vacuum pump, the vacuum valve comprises a valve housing and a cylinder housing, and a valve housing of a first stem penetrating from the valve housing into the cylinder housing. A main valve body is formed in the body, a first piston is formed in the cylinder housing, and a second piston having a cylinder function for the first piston is provided in the cylinder housing. A stem guide that can define the lowermost position of a stopper piece installed at a predetermined position of a second stem extending upward from the piston is movably attached to a cylinder housing by an adjustment handle, and each first piston and second piston are respectively It is characterized in that it can be driven by using compressed gas.

[0006]

When the compressed gas is introduced into the lower part of the first piston, the compressed gas acts on the pressure receiving surface of the first piston, and the main valve body moves slightly upward together with the first piston via the first stem. Then, a leak opening is formed. The vacuum pump is in an operating state. First, the air in the vacuum chamber is gradually sucked through the leak opening, and after a predetermined time, the air is sucked up to a pressure of about several torr where particles do not rise. After the lapse of the predetermined time, by introducing the gas to the lower portion of the second piston in the cylinder housing, the main valve body rapidly moves upward together with the second piston via the first stem.
Therefore, the large-diameter main valve device that connects the vacuum chamber and the vacuum pump is opened, and the remaining air in the vacuum chamber is exhausted. The initially formed leak opening can be adjusted very easily by moving the stem guide up and down with the handle.

[0007]

1 and 2 show a first embodiment of the present invention, in which a vacuum valve is composed of an upper cylinder casing (3) and a lower valve casing (1). .. The cylinder housing (3) is a cylinder as an actuator, and houses a second piston (5) sealed by a seal packing (4).

The cylinder housing (3) is composed of an upper cylinder chamber (3 ') and a lower cylinder chamber (3') formed by sandwiching the second piston (5). The upper cylinder chamber (3 ') and the lower cylinder chamber (3') are connected to a switchable solenoid valve (not shown), respectively, and are pressurized via the first port (19) and the second port (20). The gas supply and drain can be switched alternately.

A second stem (16) extending upward is attached to the upper part of the second piston (5), and a stopper piece (11) is formed at the tip thereof. This second
The stem (16) is slidably accommodated in a stem guide (18) having an adjusting handle (10) and attached to a cylinder housing (3) by a screwing portion (12), and a stopper piece (11) thereof. The movement is regulated by a stopper sheet (17) at the lower end of the stem guide (18). A cylinder chamber is formed in the second piston (5), and the fourth port is connected via the flexible tube (23) with the first piston (7) whose periphery is sealed by the seal packing (9) as a boundary. An upper pressure chamber (5 ') connected to (22) and a lower pressure chamber (5') connected to the third port (21) are formed.

The first piston (7) penetrates the lower surface of the second piston (5), and further penetrates the boundary between the cylinder housing (3) and the valve housing (1), and the first stem (14). Mounted on the first stem (1) extending into the valve housing (1).
A main valve body (32) having an annular sealing material (6) is attached downward to the lower end of 4), and only the stem located in the valve housing (1) is attached to the main valve body (32). It is sealed by a bellows (29) extending upward from the upper pedestal (28), and the inside of the bellows (29) is kept at atmospheric pressure by an atmosphere communication hole (30).

A main valve seat (39) which cooperates with the main valve body (32)
The lower port (41) of the valve communicates with the vacuum pump (40) and is located above the main valve seat (39).
Communicate with the vacuum chamber (43). Also, a skirt piece (13) vertically provided on the periphery of the adjustment handle (10).
Is a cylindrical portion (1) protruding from the upper end of the cylinder housing (3).
5) surrounding the skirt piece (13) and the tubular part (1
By forming a scale on each of 5), it is possible to confirm the lowering width of the stem guide (18).

With the valve closed as shown on the left side of FIG. 1, the third port (21) is provided at the lower portion of the first piston (7).
When the compressed gas is introduced from above, the compressed gas acts on the pressure receiving surface of the first piston (7), and the main valve body (32) moves to the first side via the first stem (14) as shown in the right side of FIG. Move slightly upward with one piston (7), forming a leak opening of (h) = approximately 0.5-2 mm.

The vacuum pump is in an operating state. First, the air in the vacuum chamber is gradually sucked through the leak opening, and after a predetermined time, the air is sucked up to a pressure of several torr where particles do not rise. After the lapse of the predetermined time, the main valve body (32) is caused to flow into the lower portion of the second piston (5) in the cylinder housing (3) so that the main valve body (32) is moved to the first stem (1
Rapidly move upward with the second piston (5) via 4).

Therefore, the large-diameter main valve body (32) communicating with the vacuum chamber (43) and the vacuum pump (40) is opened as shown in FIG. 2, and the remaining air in the vacuum chamber is exhausted. .. The width (h) of the initially formed leak opening is adjusted by adjusting the adjusting handle (10) and moving the stem guide (18) up and down to determine the position of the stopper seat (17).

As shown in FIG. 3, a skirt body (a stopper (24) prevents the main valve body (32) from being urged from above by a spring (34) inside the annular seal (6) and is prevented from coming out by a stopper (24). 33), and the initially formed leak opening is provided with a groove (25) formed in the skirt body (33).
You can also adjust the flow rate with. The present invention is not limited to the above embodiments, but includes embodiments at a level that can be conceived by those skilled in the art when embodying the gist of the invention.

[0016]

The present invention has the following effects. (A) By opening the skirt body having the leak opening and the large-diameter main valve device in two stages to open the vacuum valve, it is possible to prevent particles from rising due to turbulent flow without being exhausted from the atmospheric pressure all at once. (B) It is possible to operate so as to switch from slow exhaust to large-diameter exhaust simply by introducing a gas having a predetermined pressure into a single vacuum valve, and the vacuum valve has an extremely simple structure. (C) The initially formed leak opening can be adjusted very easily by moving the stem guide up and down with the handle.

[0017]

[Brief description of drawings]

FIG. 1 is a sectional view for explaining the operation of the first embodiment of the present invention.

FIG. 2 is a sectional view for explaining the operation of the first embodiment.

FIG. 3 is a partially enlarged sectional view of a main valve body used as a second embodiment.

FIG. 4 is a schematic diagram showing a conventional technique.

FIG. 5 is a schematic diagram showing a conventional technique.

[Explanation of symbols]

  (1) Valve housing   (3) Cylinder housing   (3 ') Upper cylinder chamber   (3 ') Lower cylinder chamber   (4) Seal packing   (5) Second piston   (5 ') Upper pressure chamber   (5 ') Lower pressure chamber   (6) Annular sealing material   (7) First piston   (9) Seal packing   (10) Adjustment handle   (11) Stopper piece   (12) Threaded part   (13) Piece of skirt   (14) First stem   (15) Tube part   (16) Second stem   (17) Stopper seat (18) Stem guide   (19) Port 1   (20) Second port   (21) Port 3   (22) Port 4   (23) Flexible tube   (24) Stopper   (25) Groove   (28) Pedestal   (29) Bellows   (30) Atmosphere communication hole   (32) Main valve body   (33) Skirt body   (34) Spring   (39) Main valve seat   (40) Vacuum pump   (41) Port   (42) Port   (43) Vacuum chamber

Claims (1)

[Claims] 1. A vacuum valve disposed between a vacuum chamber and a vacuum pump, wherein the vacuum valve is composed of a valve casing and a cylinder casing, and the vacuum valve penetrates from the valve casing into the cylinder casing. The main valve body is formed in the valve housing of one stem, and the first piston is formed in the cylinder housing.
A second piston having a cylinder function with respect to the first piston is provided in the cylinder housing, and a lowermost position of a stopper piece installed at a predetermined position of a second stem extending upward from the second piston is defined. The stem guide that can be installed is movably mounted on the cylinder housing by the adjustment handle,
A vacuum valve characterized in that the piston and the second piston can be driven by using gas for compressing each.