JPH0158795B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shutoff valve device used in a high vacuum device, and particularly to a passage shutoff valve device provided in a vacuum protection system of a high vacuum device.

Conventionally, as a high vacuum device, in a high vacuum atmosphere,
There are known devices configured to sequentially perform various reaction treatments, surface treatments, etc. In vacuum equipment where a line is constructed by airtightly connecting several chambers or devices with vacuum pipes or passages in order to sequentially perform various processing processes, the vacuum state may deteriorate due to misoperation or some other accident. If the degree of vacuum decreases due to breakage or slow leakage, this will be detected as quickly as possible, and the abnormal part will be isolated and shut off to prevent the vacuum drop from spreading to other parts of the high vacuum equipment. At the same time, it is necessary to provide a vacuum protection system to take measures such as repairing or replacing abnormal parts.

In the vacuum protection system of such high vacuum equipment, a fast-acting passage cutoff valve device that can be activated immediately in response to the detection of an abnormality is installed between each part of the vacuum equipment or between the vacuum pipes in each processing space or The main requirements for the functioning of the vacuum protection system are the rapid action of the passageway isolation valve device and the low leakage rate.

Due to the fast-acting nature of the passageway cutoff valve device, in practical terms, the operating time should be at least 10ms to 5ms or less after the vacuum drop reaches the detection level, from when this is detected to when the operation is completed. desirable. Further, it is practically desirable to suppress the amount of leakage, that is, the sealing conductance, to about 0.1 torrl/sec.

Conventionally, a passage cutoff valve device for a vacuum protection system of a high vacuum device includes, for example, a cutoff plate in which a valve opening is formed in a part, and this cutoff plate is guided to a valve seat surface by a narrow gap. A locking mechanism holds the blocking plate in the valve open position, which is tightly slidable and normally pulled up to the valve open position by the action of an air cylinder against a spring force.
When an abnormality occurs, a solenoid is energized by an output command from the control device to release the locking mechanism, and the blocking plate is thereby moved to the valve closing position by spring force, thereby blocking the passage. There is.

However, in a passage cutoff valve device having such a configuration, in order to obtain the desired quick action and sealing conductance as described above, the thickness of the cutoff plate is reduced to about 1 cm in order to reduce the weight of the cutoff plate and its attached parts. When the gap between the shutoff plate and the valve seat wall is 0.01mm or less, the thin shutoff plate moves up and down at high speed to open and close the guide with almost no clearance. , it is unavoidable that part or all of the shutoff plate slides at high speed while making surface contact with the valve seat surface, and as a result, wear occurs on the contact sliding surface, and this wear causes There is a serious problem that fine dust contaminates the vacuum atmosphere and causes deterioration of product quality. In order to reduce wear on such sliding surfaces, it may be possible to apply surface treatment to increase the lubricity of the contact sliding surfaces, but in high vacuum equipment, pacing is often performed to vent gas. It has been technically extremely difficult to find a surface treatment method that provides excellent lubricity under such usage conditions.

The present invention has been made in view of the above-mentioned problems, and is capable of moving a blocking plate for closing a valve port between a closed position and an open position within a plane parallel to and spaced apart from a valve seat surface. an electromagnetic device disposed in a vacuum conduit or passageway (collectively referred to herein as a passageway) so as to be movable toward the valve seat surface in a closed position and to translate the blocking plate from an open position to a closed position;
A shutoff is achieved in the passage by providing an electromagnetic device that attracts the blocking plate that has been translated to the closed position to the valve seat surface, and a control device that operates this attracting electromagnetic device with a time lag compared to the translational electromagnetic device. It is an object of the present invention to provide a passage cutoff valve device which is capable of opening and closing operations without sliding of the plate, has excellent quick action, and has a small amount of leakage.

The invention will now be explained with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of the vacuum protection system according to the present invention, in which 1 is a vacuum pipe line or vacuum passage communicating between vacuum processing equipment of a vacuum apparatus, and 2 is a line for detecting the degree of vacuum in the vacuum passage 1. A pressure detection unit composed of an ion pump, an ionization vacuum gauge, etc. is configured to quickly detect a decrease in the degree of vacuum in the vacuum passage 1 and output a detection signal to the control device 3. 4
is a passage cutoff valve device provided in the vacuum passage 1, which includes electromagnetic devices 5 and 6 that are sequentially operated with a predetermined time lag by a command signal from the control device 3.
As a result, the blocking plate 7 is attracted to the valve seat 8 and closes the valve port 9, thereby blocking the vacuum passage 1. 10 indicates a gate valve.

2 and 3 show a first example of a passage cutoff valve device according to the present invention, in which a gate valve 12 is provided at one end of an annular valve casing 11 made of austenitic stainless steel or other non-magnetic material. A rectangular valve opening 9 extending in the horizontal direction is provided approximately at the center of the wall 12, and a magnetic pole piece 15 of the suction electromagnetic device 6 is provided on the valve seat surface of the valve seat 8 surrounding the valve opening 9. A valve stem 17 made of a non-magnetic material is connected to a shielding plate 7 made of a ferromagnetic material, which is positioned approximately on the central plane of the valve casing 11 and can close the valve port 9 by closely contacting the magnetic pole piece 15. The valve stem 17 is extended upward almost vertically through the provided hole 18, and the valve stem 17 is passed through a metal bellows 19 that is airtightly fixed to the upper end of the valve casing and shields the vacuum inside the valve casing from the outside air. and fixed to the metal bellows upper end plate 20 so that the shutoff plate 7 is in the valve open position slightly above the valve opening 9 and in a vertical plane spaced parallel to the pole piece 15 at a small distance from the valve stem 17 and the valve stem 17 . It is suspended and supported by metal bellows 19.

The electromagnetic coil 21 of the electromagnetic device 5 for translation is provided above the metal bellows 19, and the movable iron core 2
2 is connected to the extended end of the valve stem 17, so that when the electromagnetic device 5 is energized, the valve stem 17, and therefore the blocking plate 7, can be pushed down to the valve port closing position against the spring force of the metal bellows 19. . 23 is the valve outer box 11
The connecting flange is shown.

The operation of the passage cutoff valve device 4 configured as described above will be explained with reference to FIG. In the illustrated electromagnetic coils, those with diagonal lines indicate an excited state, and those with blank spaces indicate a demagnetized state.

FIG. 6a shows a state in which the vacuum in the vacuum passage 1 is maintained normally, and the shielding plate 7 is connected to the metal bellows 1.
9 is supported at a position above the valve port 9, and the valve port 9 is open.

Now, when the degree of vacuum in the vacuum passage 1 shown in FIG. A current flows through the lowering electromagnetic coil 21, which causes the movable iron core 22 to push down the valve stem 17 against the spring force of the metal bellows 19, and the cutoff plate 7
is lowered to a height corresponding to the valve opening closing position as shown in FIG. 6b.

At the same time that the shielding plate 7 finishes descending, current flows from the control device 3 to the attraction electromagnetic device 6, and the shielding plate 7 is attracted to the electromagnetic plate 15, thereby causing the sixth
Close the valve port 9 as shown in Figure c.

When the failure part of the vacuum device is repaired and the degree of vacuum in the vacuum passage 1 returns to a predetermined value, the control device 3 activates the suction electromagnetic device 6 based on the detection signal from the pressure detection section 2.
The energization to the electromagnetic device 5 for translation is then stopped, whereby the blocking plate 7 returns to the vertical position as shown in FIG. 6d due to the restoring force of the metal bellows 19. The blocking plate 7 rises to the normal position due to the restoring force of the metal bellows 19, and the sixth
Open the valve port 9 as shown in Figure e.

In the example described above, the metal bellows 19 is used to isolate the vacuum in the vacuum passage 1 from the outside air, and is movable so that the valve stem 17 can follow the operation of the electromagnetic device 5 for translation and the electromagnetic device 6 for suction. Valve stem 17
The shield plate 7 is held in the valve open position by supporting the valve.

It is preferable to use a welded bellows type as the metal bellows 19, and a welded bellows has a characteristic that the rigidity is low in the axial direction and the inclination direction, and the rigidity is high in the direction perpendicular to the axis. Therefore, the blocking plate 7 and the valve rod 17 perform vertical translational movement on the center line of the electromagnetic coil 21, and when the electromagnetic device 6 acts as an attraction,
The shielding plate 7 is slightly inclined with the supporting point of the valve rod 17 on the upper end plate 20 of the bellows 19 as a fulcrum, and is brought into close contact with the surface of the broken pole piece 15 on the valve seat surface. In order to ensure complete contact between the blocking plate 7 and the valve seat surface, it is preferable that the surface of the magnetic pole piece 15 be inclined in accordance with the inclination of the blocking plate 7.

FIGS. 4 and 5 show other embodiments of the present invention, in which similar parts to those described above in the drawings are given the same reference numerals as described above, and detailed explanation thereof will be omitted.

In the present invention, the valve stem 17 of the blocking plate 7 and the movable core 22 integrally connected to its upper end are all provided in a vacuum. For this purpose, an upper end closed cylindrical chamber body 24 made of non-magnetic material is airtightly fixed to the upper end of the valve casing 11 by welding or other suitable method to provide an iron core space 25 extending upward through the upper end hole 18. space 2
5, the movable core 22 and the valve rod 17 are inserted so as to be able to move up and down leaving an appropriate gap between them and the inner circumferential wall of the chamber body 24, and a retainer 26 is provided at the lower end of the core movement space 25. During a power outage, etc., the movable core 22 is held in the moving space 25 in the valve closed position.

The translational electromagnetic device 5 is provided with a descending electromagnetic coil 21 for opening and closing the valve, and a rising electromagnetic coil 27 for opening the valve.
7 are installed vertically in the outside of the chamber body 24, that is, in the outside air.

The operation of the passage cutoff valve device having the above-mentioned structure is
This will be explained with reference to the diagram. Note that, as described above, among the illustrated electromagnetic coils, the ones with diagonal lines indicate the excited state, and the blank ones indicate the demagnetized state.

FIG. 7a shows a state in which the vacuum in the vacuum passage 1 is normally maintained, and in the normal operating state of the vacuum device, the lifting electromagnetic coil 27 of the translation electromagnetic device 5 is energized and movable. Iron core 22
is pulled up into the space 25, the blocking plate 7 is placed in the raised position, and the valve port 9 is opened.

FIG. 7b shows that when the degree of vacuum in the vacuum passage 1 falls below a predetermined value, the ascending electromagnetic coil 27 is demagnetized by a closing command signal from the control device 3, and at the same time, the descending electromagnetic coil 21 is excited. This shows a state in which the movable core 22 is pulled down within the space 25 and the shielding plate 7 is lowered to a height corresponding to the valve port closing position.

In this manner, at the same time as the cutoff plate 7 finishes descending, current flows from the control device 3 to the attraction electromagnetic device 6, and the cutoff plate 7 is attracted to the electromagnetic plate 15, thereby causing the valve to open as shown in FIG. 7c. Close mouth 9. At this time, in this example, unlike the above-described example, the blocking plate 7, the valve rod 17, and the movable core 22 move together in parallel toward the valve seat surface.

7d and 7e show the sequential operation when the blocking plate 7 returns from the valve closed position to the valve open position. First, the attraction electromagnetic device 6 is demagnetized, and then the translation electromagnetic device 5 is lowered. At the same time as the electromagnetic coil 21 is demagnetized, the lifting electromagnetic coil 27 is energized, whereby the blocking plate 7 is separated from the valve seat and then pulled up to the valve open position and held in the state shown in FIG. 7e.

FIG. 8 shows the sealed conductance in each of the operating states a to e in FIGS. 6 and 7.

According to the present invention, the effects listed below can be obtained.

(1) Since there are no sliding parts in the vacuum atmosphere, it is possible not only to eliminate the problem of contamination of the vacuum atmosphere by fine powder caused by abrasion of the sliding surface, but also to reduce the sealing effect caused by abrasion of the shield plate surface. This can prevent the problem of unstable operating characteristics due to sliding resistance.

(2) The adsorption effect allows the blocking plate to adhere almost completely to the valve seat, greatly improving the sealing effect.

(3) Since there is no tripping mechanism and the shielding plate is operated directly from the electromagnetic device, the time from the occurrence of the phenomenon to the completion of operation can be further shortened.

(4) The operating characteristics of the solenoid and movable core, which provide the driving force, reverse when the center point of the solenoid is passed and become a braking force. There is almost no impact on each part. Therefore, durability can be significantly improved.

(5) Since the configuration is simple, the entire device can be miniaturized. Furthermore, the weight of the movable parts can be significantly reduced, which is advantageous in shortening operating time.

(6) Since there are no worn parts in the entire device, there is no risk of the operating characteristics changing due to wear during long-term use, and durability and reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a vacuum protection system of a vacuum device, FIG. 2 is a front view of a passage isolation valve device according to the present invention, FIG. 3 is a longitudinal sectional view of the passage isolation valve device shown in FIG. The figure is a front view showing another embodiment of the passage cutoff valve device according to the present invention, FIG. 5 is a longitudinal sectional view of the passage cutoff valve device shown in FIG. 4, and FIG.
FIG. 7 is an explanatory diagram of the operation of the passage cutoff valve device shown in FIGS. 4 and 5, and FIG. 8 is a diagram showing the sealing conductance of the device according to the present invention. . DESCRIPTION OF SYMBOLS 1... Vacuum pipe line or passage, 2... Pressure detection part, 3... Control device, 4... Passage cutoff valve device, 5
... Translation electromagnetic device, 6... Attraction electromagnetic device, 7... Shutoff plate, 8... Valve seat, 9... Valve port, 1
DESCRIPTION OF SYMBOLS 1... Valve casing, 12... Partition wall, 15... Magnetic pole piece, 17... Valve stem, 19... Metal bellows, 21
...Descent electromagnetic coil, 22...Movable iron core, 25
... Iron core movement space, 27 ... Electromagnetic coil for ascending.

Claims (1)

[Claims] 1. In a shutoff valve device equipped with a shutoff plate that seats on a valve seat provided in a high vacuum device and closes a valve port, the shutoff plate is held in a valve open position within a plane slightly spaced forward from the valve seat. and a translation device having a movable iron core integrally connected to the cutoff plate and configured to translate the cutoff plate in the plane from the valve open position to the valve closed position corresponding to the valve seat when energized. A moving electromagnetic device, a suction electromagnetic device provided to attract and seat the blocking plate in the valve closing position toward the valve seat, and the translational electromagnetic device and the suction electromagnetic device are connected to each other for a predetermined time lag. 1. A shutoff valve device for a high vacuum device, comprising: a control device for controlling the operation of the high vacuum device.