JPH04107375A - Vacuum valve - Google Patents

Abstract

PURPOSE:To prevent the occurrence of discharge at a stretch and to prevent the occurrence of turbulence of air by providing an auxiliary valve device with a small bore through which a vacuum chamber is communicated to a vacuum pump and a main valve device with a large bore, and performing two-stage opening of a valve by using the above two valve devices. CONSTITUTION:When compressed gas is introduced from a three-way valve 18 to a pressure introduction hole, the gas flows to a pressure chamber 8 through an opening 17 and a throttle valve 20. A piston 5 is gradually raised by means of a pressure, and the gas gradually flows to a pressure chamber 8 only through a throttle valve 20. In this state, only an auxiliary valve body 27 is raised and air in a vacuum chamber 43 and a valve casing 1 is gradually sucked in a vacuum pump 40 through an auxiliary valve seat 33 by means of a horizontal port 34. When the piston 5 is further raised, after the gas passes a gap between a check packing 23 and the piston 5, the gas rapidly flows to the pressure chamber 8 to open a main valve body 32 with a large bore and is rapidly sucked in the vacuum pump 40. Thereafter, when a three-way valve 18 is switched to discharge the gas, the gas is discharged from the pressure chamber 8, and the piston 5 is pressed down through the force of a first energizing spring 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vacuum valve that is interposed between a vacuum chamber and a vacuum pump when the vacuum chamber is brought into a vacuum state.

[Conventional technology]

Conventionally, in order to make a vacuum chamber used for semiconductor manufacturing, etc. close to vacuum, the vacuum chamber (01) and the vacuum pump (02) are connected with a conduit (03), and the vacuum pump (0
2), but since it is through a single vacuum valve (04), when the vacuum valve (04) is opened, a rapid evacuation causes the vacuum chamber (01) and conduit (03) to
The high exhaust speed inside creates turbulent flow, and particles fly up.

In order to prevent this, in recent years, as shown in FIG. (05) is attached and both vacuum valves are used together to perform vacuuming in stages.

That is, when evacuating the vacuum chamber (01), the small-diameter vacuum valve (05) is first opened, and the vacuum pump (01) is opened.
In step 2), the conduit (30) and vacuum chamber (01) are gradually evacuated to about several torr. In a vacuum state of several torr, the molecular weight is not large enough to kick up particles, and after that, the large-diameter vacuum valve (05) is fully opened and vacuum evacuation can be carried out stably.

However, controlling both the small-diameter vacuum valve (05) and the large-diameter vacuum valve (04) over time using the controller (07) is not only complicated to operate and adjust, but also expensive. It also becomes expensive.

Furthermore, manual operation may cause malfunctions.

[Problems to be Solved by the Invention] The present invention operates a vacuum valve so as to automatically switch from slow exhaust to large-diameter exhaust simply by introducing compressed gas into the actuator of one vacuum valve. This solves the problems of the prior art.

[Technical means to solve the problem]

In a vacuum valve disposed between a vacuum chamber and a vacuum pump, a throttling means for gradually introducing pressurized gas into a cylinder housing to raise a piston when the vacuum valve is started;
an opening means that opens at a set raised position of the piston and introduces a large amount of pressurized gas into the cylinder housing; and a small-diameter sub-valve device that communicates the vacuum chamber and the vacuum pump by moving the piston using a throttle means. A vacuum valve comprising a large-diameter main valve device that communicates a vacuum chamber with a vacuum pump by moving a piston using an opening means.

[For production]

When the compressed gas starts to be introduced into the cylinder housing of the vacuum valve, the compressed gas begins to act on the pressure receiving surface of the piston via the throttle means. The piston begins to gradually rise, and during this movement, the small diameter secondary valve device opens. When the vacuum pump is in operation, the air in the vacuum chamber is gradually sucked through a small-diameter opening, and the pressure reaches a pressure of several torr without any particles being thrown up.

When the piston reaches a predetermined raised position, the opening means that introduces a large amount of pressurized gas into the cylinder housing opens, and the pressurized gas acts rapidly on the pressure-receiving surface of the piston, causing the piston to move forcefully. , the large diameter main valve device communicating with the vacuum chamber and the vacuum pump opens to evacuate the remaining air in the vacuum chamber.

〔Example〕

1 and 2 show a first embodiment of the present invention, in which a vacuum valve is arranged between an upper cylinder housing (3) and a lower valve housing (1) with an intermediate plate (2) in between. It is composed of.

The cylinder housing (3) is a cylinder serving as an actuator, and houses a piston (5) sealed with a seal packing (4).

An atmosphere communication hole (6) is bored in the upper part of the cylinder housing (3), and the upper part of the piston (5) is maintained at atmospheric pressure and the piston (5) is supported by the first biasing spring (7). It is biased downward.

The lower part of the piston (5) is a pressure chamber (8) into which pressurized gas is introduced, and the piston (5) has a pressure receiving step (9) facing the pressure chamber (8) and a pressure receiving step (9) facing the pressure chamber (8), and The first body portion (10), the first tapered step portion (11), and the 211f provided
(12), and a second tapered step (13).

Further, a stem (14) having a male thread extends so as to pass through the center of the piston (5) from below to above, and is fastened to the piston with an upper nut (15).

A pressure reservoir chamber (16) concentric with the stem (14) is formed in the intermediate plate (2), and a pressure reservoir chamber (16) is formed in the intermediate plate (2).
It is possible to communicate with the upper pressure chamber through an opening (17) having a diameter larger than that of the opening (17).

The pressure reservoir chamber (16) communicates with a pressure introduction hole (19) that communicates with a pressurized gas supply device (not shown) via a three-way valve (18), and also communicates with the pressure chamber (8) via a throttle valve (20).
The bypass hole (21) communicates with the bypass hole (21).

Furthermore, the first tapered part' (11) of the piston (5) located in the pressure reservoir chamber (16) is provided with an annular sealing material (22) corresponding to the upper valve seat (25) and a second body part. A seal support base (24) equipped with a lip-shaped non-return gasket (23) that comes into contact with the pressure chamber (12) is movable from the bottom with a gap left between the inner peripheral surface and the pressure reservoir chamber (16). It is pressed by a force spring (26). The seal support stand (24) and the first tapered step (
A cutout groove is formed on the contact surface with 11), allowing fluid to flow freely on the contact surface.

The tip of the stem (14) extending into the valve housing (1) is a sub-valve body (27), and the upper part of the stem (14) is connected to the pedestal (28) at the top of the sub-valve body (27). It is sealed with a bellows (29) extending upward, and the inside of the bellows (29) is maintained at atmospheric pressure through an atmospheric communication hole (30).

An annular seal (31) is formed on the sub-valve body (27),
A small-diameter sub-valve seat (33) formed in the main valve body (32) is sealed.

In addition, a plurality of horizontal boats (
34) is perforated. The recess (35) at the top of the main valve body (32) has a pedestal (28) having a protrusion (36) at the bottom.
) is inserted, and a stopper piece (3) is inserted at the top of the recess (35).
7) allows the main valve body (32) and the sub-valve body (27) to move relative to each other against the pressing force of the internal second biasing spring (38).

A first port (41) at the lower part of the main valve seat (39) that cooperates with the main valve body (32) communicates with the vacuum pump (40), and a second port (41) located above the main valve seat (39) communicates with the vacuum pump (40). The boat (42) is
It communicates with the vacuum chamber (43).

In this embodiment, when compressed gas is not supplied from the three-way valve (18), the first biasing spring (7), which is the strongest,
- button (5) is pushed down and the parts maintain the positions shown in FIG. At this time, the valve seat (25
) and the annular sealing material (22) (h□) is approximately 1 m.
/m, and the protruding piece (36) of the pedestal (28) of the valve housing (1)
and the stopper piece (37) (h2) is approximately 2 m/
The position is adjusted as m.

When the three-way valve (18) is switched and compressed gas is introduced into the pressure introduction hole, the gas flows between the intermediate plate (2) and the non-return packing (23), as shown in Figure 2 (a). It flows into the pressure chamber (8) through the gap and the opening (17), and also flows into the pressure chamber from the bypass hole (21) via the throttle valve (20).

The piston (5) gradually rises due to the pressure, and when the annular sifur material (22) comes into contact with the valve seat (25), the piston (5) reaches the position shown in Fig. 2 (
The water flows only through the bypass hole (21).

When the piston (5) further rises and reaches the position shown in FIG. Patsukin (23
), a large amount of compressed gas in the pressure reservoir chamber (16) flows into the pressure chamber (8).

From the position in Figure 2 (a) to the position in Figure 2 (mouth), (h
During the rise of approximately 1 m/m, the pedestal (2
8) The distance between the protruding piece (36) and the stopper piece (37) (
h engineering)=approximately 2 m/m, only the sub-valve body (27) rises, the sub-valve seat (33) and the annular sealing material (31) of the sub-valve body (27) are separated, and the vacuum chamber ( 42) and valve housing (1
) is sucked little by little into the vacuum pump (40) via the horizontal port (34) and the sub-valve.

In the position shown in Figure 2 (opening), the throttle valve (20
), the compressed gas is gradually introduced into the pressure chamber (8), delaying the time it takes to reach the position shown in Figure 2 (c), and the air pressure in the vacuum chamber (42) is increased to several torr using only the sub-valve. lower to

Upon reaching the position shown in Figure 2 (c), the pressurized gas passes between the check packing (23) and the piston (5), rapidly flows into the pressure chamber (8), and the main valve body (32) Open and quickly evacuate remaining air.

Thereafter, when the three-way valve (18) is switched to discharge the compressed gas, the compressed gas is exhausted from the pressure chamber (8) so as to push open the check packing (23).

FIG. 3 shows a second embodiment of the present invention, in which the pressure chamber (
8) The only difference is the mechanism for introducing compressed gas, and the rest is the same as in the previous embodiment.

The piston (5) is inserted into the opening (17) of the intermediate plate (2).
It has a body part (45) and a tapered step part (44) which are inserted with a gap between them. ,
It is in contact with the trunk (45).

Switch the three-way valve (18) to transfer compressed gas to the pressure reservoir chamber (16).
), the compressed gas flows only through the bypass hole (21) and gradually flows into the pressure chamber (8) via the throttle valve (20), which is regulated.

As the piston (5) rises, the sub-valve seat (33) and the annular sealing material (31) of the sub-valve body (27) are separated, and the vacuum chamber (
13) and the air in the valve housing (1) is sucked little by little into the vacuum pump (40) via the horizontal boat (34) and the sub-valve.

When the check packing (23) reaches the tapered step (44), the pressurized gas in the pressure chamber (16) passes through the check packing (23).
23) and the piston (5), and the pressure chamber (8
), the main valve body (32) opens and the remaining air is rapidly exhausted.

In both embodiments 1.2, the sub-valve body (27) and the main valve body (32) are biased in the vertical direction by the second biasing spring (38), and the protruding piece (36) acts as a stopper. The main valve remains open when in contact with the piece (37), and even if the piston (5) suddenly descends downward after exhaustion is finished, the main valve body (32) and main valve seat (39) And the stem (14) will not be damaged.

〔Effect of the invention〕

The present invention has the following effects.

(a) By opening the vacuum valve in two stages: a small-diameter sub-valve device and a large-diameter main valve device, atmospheric pressure is not exhausted all at once, and particles can be prevented from flying up due to turbulence.

(b) It is possible to prevent particles from flying up due to turbulent flow by appropriately adjusting the throttle valve depending on the capacity of the vacuum pump, the capacity of the vacuum chamber, the required degree of vacuum, etc.

(c) By simply introducing compressed air into the actuator of one vacuum valve, two-stage exhaust can be achieved, which not only reduces the number of parts but also simplifies operation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the first embodiment of the present invention, FIG. 2 is a partially enlarged explanatory diagram of the operation of FIG. Both FIG. 5 and FIG. 5 are schematic diagrams showing the prior art. (1) Valve housing (2) Intermediate plate (3
) Cylinder housing (4) Seal packing (5)
Piston (7) First biasing spring (9) Pressure receiving step (11) First taper step (13) Second taper step (15) Nut (17) Opening (19) Pressure introduction hole (21) Bypass hole (23) Check packing (25) Valve seat (27) Sub-valve body (29) Bellows (31) Annular sealing material (33) Sub-valve seat (35) Recess (37) Stopper piece (39) Main valve seat (41 ) First boat (43) Vacuum chamber (6) Atmospheric communication hole (8) Pressure chamber (10) First body (12) Second body (14) Stem (16) Pressure reservoir chamber (18) Three-way valve ( 20) Throttle valve (22) Annular sealing material (24) Seal support base (26) Third biasing spring (28) Pedestal (30) Atmospheric communication hole (32) Main valve body (34) Horizontal boat (36) Projection piece (38) Second biasing spring (40) Vacuum pump (24)' Second boat ('44) Tapered step (45) Body (46) Annular notch Fig. 4 Fig. 5

Claims (4)

[Claims] (1) In a vacuum valve disposed between a vacuum chamber and a vacuum pump, when the vacuum valve is started, compressed gas is gradually introduced into the cylinder housing to raise the piston, and the piston is an opening means that opens at a set raised position and introduces a large amount of pressurized gas into the cylinder housing; a small-diameter auxiliary valve device that communicates the vacuum chamber and the vacuum pump by movement of the piston by the throttle means; A vacuum valve comprising a large-diameter main valve device that communicates a vacuum chamber and a vacuum pump by means of movement of a piston. (2) The vacuum valve according to claim (1), wherein the throttle means is a throttle valve. (3) The vacuum valve according to claim (1), wherein the throttle means is a combination of a check packing that opens when the piston moves upward, and a throttle valve. (4) The vacuum valve according to claim (1), wherein the piston and the sub-valve body are integrated with a stem.