KR100230936B1 - Vacuum gate valve - Google Patents

Abstract

The vacuum gate valve having a vacuum passage includes a valve casing (1), a valve body reciprocating between two positions to open and close the vacuum passage, a bonnet flange (9) for closing the casing (1), and a bonnet flange (9). A drive means (10) provided on the bonnet flange (9) for loosely inserted into the through hole (11) of the stem shaft (3) to engage the valve body and to reciprocally drive the valve body; And a member for isolating the sliding portion of the stem shaft 3 from the passage.

Description

Vacuum gate valve

1 is a cross-sectional view showing the structure of an example of a vacuum gate valve according to the present invention.

2 is a cross-sectional view showing the structure of a valve casing as an example of a gate valve according to the present invention.

3 is a perspective view for explaining the valve seat of the gate valve according to the present invention.

Figure 4 is a perspective view for explaining the valve body of the gate valve of the present invention.

5 is a perspective view showing the entire configuration of the gate valve of the present invention divided into a valve body and a valve seat.

6A and 6B are explanatory views showing two examples of a planar shape of the valve seat taken in a plane including the opening axis of the valve seat, respectively, in the present invention.

7 is a sectional view showing the structure of an example of a conventional gate valve.

* Explanation of symbols for main parts of the drawings

1, 60: valve casing 2, 40: valve plate (or valve body)

3: stem axis 4: bellows

5: moving flange 6: fixed flange

7: Straight bearing inside 8: Straight bearing

9 bonnet flange 10 drive means

11 through hole 13 reciprocating means or actuator

14: guide means 16: valve seat

20: opening 30: sealing material

110: seal sheet surface 110A, 110B, 110C: seal surface

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum gate valve used as a dilution valve for a vacuum container in a semiconductor manufacturing apparatus, and more particularly, to a seal structure and a guide mechanism for stamping a vacuum gate valve.

In a conventional gate valve of this type, in order to open and close the valve plate or to push the valve plate against the valve seat, the stem shaft coupled to the valve plate through the bellows is operated by a driving means such as a manual or compressed air cylinder.

7 is a sectional view showing the structure of an example of a conventional vacuum gate valve. In FIG. 7, reference numeral 1 denotes a valve casing, 2 denotes a valve plate (or valve body) for opening and closing a vacuum passage formed in the valve casing by reciprocating between two positions, and 3 denotes a valve plate 2 ) Denotes a stem shaft coupled to the shaft, 9 denotes a bonnet flange for closing the valve casing 1, and 70 denotes an injury inserted into a through hole formed in the bonnet flange 9 to slidably guide the stem shaft 3. 4 denotes a bellows connecting the receiver on the stem shaft 3 and the bonnet flange, and 10 denotes a driving means which is a reciprocating actuator of the stem shaft 3.

In the above-described conventional vacuum gate valve, since the stem shaft 3 and the bushing 70 are slidably coupled to each other in a vacuum state, it may be difficult to open and close the valve by mutual friction. In addition, these parts wear and generate dust, contaminating pure vacuum conditions. Therefore, the conventional gate valve cannot be used in a semiconductor manufacturing apparatus or the like.

As another example of a conventional gate valve of this type, as disclosed in Japanese Patent Application (OPI) No. 312574/1988 ("OPI means application publication), the valve plate is pressed by means such as a cam. Gate valves having a mechanical structure of the type have a difficulty in producing abrasive powder when they slide together.

In order to overcome this problem, Japanese Patent Application (OPI) No. 261573/1989 discloses a dilution valve for supplying compressed air to a space where a bellows is formed to obtain a sealing effect. This prior art has a drawback in that it is difficult to switch the inlet air pressure according to the valve opening and closing operation, and the compressed air is introduced into the vacuum container while the bellows is broken.

In order to solve the above problems, Japanese Patent Application (OPI) No. 218628/1989 discloses a sealing structure having a sealing surface and a closure member. However, in the prior art, when the chambers on both sides of the closing member have different pressures, a large force acts on the closing member in the direction of the axis of the opening so that the piston rod is bent or the closing member moves slightly in the axial direction so that the sealing member Damage to the system should be solved.

According to a first aspect of the present invention, a valve casing, a valve body disposed in the valve casing to open and close a vacuum passage while reciprocating between two positions, a bonnet flange which closes the casing and has a through hole, into the through hole A stem shaft coupled with the valve body to be loosely inserted, the driving means disposed on the bonnet flange to reciprocally drive the valve body, the guide means for guiding the stem shaft between the two positions, and the guide means. The above-mentioned problem is solved by providing a vacuum gate valve comprising an isolation means for isolating the vacuum passage.

As the stem axis moves out or inward, the bellows having both ends connected to the bonnet flange and the bellows movable flange connected to the stem axis contracts or extends with the movement of the stem axis. Therefore, the stem shaft, the bellows movable flange connected to the stem shaft and the linear guide bearing connected to the bellows movable flange are slidably guided by the linear guide shaft so that the valve plate smoothly performs the valve closing operation or the valve opening operation.

In the vacuum gate valve of the present invention, the slide guide mechanism composed of the linear motion bearing and the linear guide shaft is provided outside the vacuum state, that is, outside the bellows. Therefore, the vacuum gate valve of the present invention does not have the drawbacks of the conventional vacuum gate valve that the stem shaft and the bushing rub against each other to open and close the valve, and wear to create dust to contaminate the pure vacuum state.

According to a second aspect of the invention there is provided a valve seat, the valve seat comprising an upper face and an oval seal seat face, the single seat face forming a first predetermined angle α with respect to the upper face. The first seal surface tapered in a cold direction, and the second seal surface having a pair of side surfaces interconnecting the pair of side surfaces of the second seal surface having a pair of side surfaces while continuing to the first seal surface and forming a constant second predetermined angle β with respect to the upper surface. The third seal surface has an opening through which the valve seat passes, and a valve body coupled to the seal seat surface to open and close the opening, wherein the valve body includes a valve plate, a first seal portion integrated with each other, and a second seal. The above-described problem by providing a vacuum gate valve comprising a seal member 30 in contact with the first seal surface, the second seal surface and the third seal surface, including a portion and a third seal portion. To solve the problem.

The vacuum gate valve device according to the third aspect of the present invention is a valve casing, a first position slidably disposed in the valve casing, and a first position corresponding to the closed state of the vacuum passage and a second position corresponding to the open state of the vacuum passage. A valve body slidably moved between the valve body, a bonnet flange having a through hole at the same time closing the valve casing, and a stem axis extending through the through hole to engage the valve body, wherein the valve body is moved to the first position and the second position. Drive means for driving between positions, guides the stem shaft, at least one guide shaft extending from the bonnet flange, bearings slidably coupled to the respective guide shafts, and slidably attached to the guide shafts through the bearings Guide means including a moving flange.

The vacuum gate valve is configured as described above. Therefore, when the valve is to be closed, the valve body having the seal member moves so that the first to third seal member portions of the seal member come into close contact with the first to third seal surfaces. As a result, the first seal member is compressed by the taper effect due to the angle α of the first seal face, and similarly, the second seal member part is compressed by the taper effect due to the angle β of the second seal face. The third seal member is pushed against the third seal face by the valve body and compressed. That is, the opening is hermetically closed. On the other hand, when attempting to open the valve, the valve body moves in the opposite direction to open the opening.

Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.

1 shows a structure of an example of a vacuum gate valve according to the present invention. Reference numeral 40 in FIG. 1 denotes a valve plate reciprocating between two positions for opening and closing the vacuum passage formed in the valve casing 60. 3 shows the stem shaft connected to the valve plate 40, and 9 shows the bonnet flange which closes the valve casing 60. As shown in FIG.

The stem shaft 3 connected to the valve plate 40 is loosely inserted through the through hole 11 formed in the bonnet flange 9. The stem 3 shaft is also loosely inserted into the bellows 4 and one end thereof is connected to the bellows fixing flange 6 secured to the bonnet flange 9. The other end of the bellows 4 is fixed to the bellows moving flange 5, which is connected to the stem shaft 3 and the linear guide bearing 7.

The linear guide bearing 7 is slidably guided by the inner shaft 8 during the straight line provided outside the bellows 4. Reciprocating means such as the actuator 13 are connected to the end of the stem 3 on the side of the bellows moving flange 5. The reciprocating means 13 may be manually operated.

The drive means 10 comprise a reciprocating means 13 and a guide means 14. The guiding means 14 is provided at the center of the bellows moving flange 5 and the bellows moving flange 5 which are arranged through a linear guide bearing 7 slidably connected by a bonnet flange 9, a straight inner shaft 8. And a linear guide shaft 8 provided at right angles to the connected stem shaft.

The inner diameter of the bellows 4, the inner diameter of the bellows fixing flange and the diameter of the through hole formed in the bonnet flange 9 are larger than the outer diameter of the stem shaft 3. Therefore, the stem shaft 3 is not in contact with these parts 4, 6, 9. That is, the stem axis is loosely inserted into these parts.

In the vacuum gate valve of the present invention configured as described above, the valve plate 40 is opened and closed as follows. The actuator (13) operates the stem shaft (3) in and out to move both ends connected to the bellows fixing flange (6) fixed to the bonnet flange (9) and to the bellows moving flange (5) connected to the stem shaft (3). The excited bellows 4 contracts or expands as the stem axis 3 moves. Therefore, the stem shaft 3 and the bellows moving flange 5 connected to the stem shaft and the linear motion guide bearing 7 connected to the bellows moving flange are slidably guided by the inner shaft 8 during the straight line, so that the valve plate 40 This valve closing operation or valve opening operation is smoothly performed (the valve plate 40 moves up and down as indicated by the arrow in FIG. 1).

In the above-described embodiment, the slide guide mechanism made of the linear motion guide bearing 7 and the linear shaft 8 is provided outside the bellows 4, ie outside the vacuum. Therefore, the vacuum gate valve of the present invention is a defect that occurs in the conventional vacuum gate valve that the stem shaft (3) and the bushing (30) rub against each other to prevent opening and closing of the valve and to generate dust as it is worn to contaminate the pure vacuum state. There is no

Figure 2 is a cross-sectional view showing the structure of the valve case in the implementation of the gate valve according to the present invention, Figure 3 is a perspective view for explaining the valve seat of the gate valve according to the present invention, Figure 4 is a 5 is an exploded perspective view showing an entire arrangement of a gate valve having a valve body and a valve seat separated from each other.

In the gate valve, as shown in FIG. 3, the valve seat 16 has a seal seat surface that is substantially in the shape of a racing track. The seal seat surface 110 is composed of a first seat surface 110A, two second seal surfaces 110B and 110B, and a third seal surface 110C.

The first seal surface 110A is substantially conical and has an angle α with the horizontal plane B including the opening axis A-A and has an upper peripheral portion tapered inward. The two second seal surfaces 110B and 110B extend from the two arc portions R of the first seal surface 110A forming the horizontal plane B and the angle β.

The valve seat 16 has an opening 20 extending in the direction of the opening axis A-A surrounded by these first to third seal surfaces 110A, 110B, 110B, 110C. As shown in FIG. 4, the closed box-shaped valve casing 60 engages with the valve seat 16 set at the bottom. The valve seat 40 is accommodated on top of the valve casing 60. That is, the valve plate 40 is coupled to the seal seat surface 110 in the shape of a race track to open and close the opening 20.

As shown in FIG. 4, the seal member 30 is formed on the valve plate 40. The seal 30 is composed of first to third seal members 30A, 30B, 30B, and 30C integrated with each other, and each of the first to third seal surfaces 110A, 110B, 110B, and 110C. The valve plate 40 moves in a direction perpendicular to the horizontal plane B. As shown in FIG. The seal member 30 is designed to be in close contact with the first to third seal surfaces 110A, 110B, 110B, and 110C. In FIGS. 4 to 5, reference numeral 30AB denotes that the first seal member 30A T-shaped intersections intersecting with the second seal members 30B and 30B are displayed.

The stamp shaft 3 is connected to the center of the upper surface of the valve plate 40. The stem shaft 3 connected in this way passes through the bonnet flange 9 provided on the valve body side and is connected to a drive means 10 such as an air cylinder mounted on the flange 9. At the connection point, the sealing structure is of a linear motion inlet type with bellows (not shown).

The bonnet flange 9 is hermetically connected to the bonnet flange 65 of the valve casing 60 through a seal such as an O-ring. The drive means 10 is configured to move the valve plate 40 through the stem shaft 3.

The configuration of the gate valve of the present invention is as described above. When the gate valve is to be closed, the valve plate 40 moves in the axial direction perpendicular to the horizontal plane B. As shown in FIG. That is, the valve plate 40 moves downward so that the seal member 30 can be pressed against the seal surfaces 110A, 110B, 110B, and 110C of the valve seat 16, so that the opening 20 is sealed. It is closed. On the other hand, when opening the gate valve, the valve plate 40 moves upward in FIG. 5 so that the opening 20 is opened.

The angle α of the first seal surface 110A with respect to the horizontal plane B does not always need to be equal to the angle β of the second seal surfaces 110B and 110B with respect to the horizontal plane B. If the angles are not the same, the seal surface 110A meets the seal surfaces 110B and 110B while forming a smooth curve. When the angles of the seal face are the same, the valve seat can be easily machined. In consideration of the slide angle between the seal face and the seal material and the compression angle of the seal material, the angle of the seal face should be about 60 degrees. However, it is clear that the same sealing effect can be obtained at different angles.

The arc portion R of the first seal surface 10A and the first seal member 30A combined with the first seal surface are semicircular in cross section as shown in part (a) of FIG. 6, or the part of FIG. As indicated by L in (b), it may be partially straight or in other forms similar to those described above.

The third seal surface 110C does not always need to be a straight line. For example, this may be part of an arc surface.

As described above, in the vacuum gate valve of the present invention, the valve plate 40 is disposed in the valve casing 60 capable of reciprocating between two positions to open and close the vacuum passage, and connected to the valve plate 40. The stem shaft 3 is loosely inserted into the through hole 11 formed in the bonnet flange 9 which closes the valve casing 60, and one end of the expandable bellows 4 in which the stem shaft 3 is loosely inserted is It is fixed to the bonnet flange (9), the other end of the bellows (4) is fixed to the bellows movable flange (5) coupled to the stem shaft (3), the bellows movable flange (5) is arranged outside the bellows (4) It is connected to the inner bearing 7 during the linear movement which is slidably guided by the inner shaft 8. That is, the slide guide mechanism composed of the linear guide bearing 7 and the linear shaft 8 is provided on the outside of the bellows 4, ie on the outside of the vacuum atmosphere. Therefore, the vacuum gate valve of the present invention has a problem of generation of contamination of the pure vacuum atmosphere due to friction or delay of operation or wear to the extent that the stem shaft 3 and the seal member 30 are in friction with each other to prevent opening and closing of the valve. Can be solved. Therefore, the vacuum gate valve of the present invention can be applied to a semiconductor manufacturing apparatus requiring pure vacuum atmosphere.

According to a second aspect of the invention, the shape of the racetrack is such that the seal seat surface 110 is formed on the valve seat 16. The seal sheet surface 110 is configured as follows: a first seal surface 110A that is conical and has a surface B including an open axis AA and an upper peripheral portion forming an angle α and tapering inwardly. ; Second seal surfaces 110B and 110B extending from two arch portions R of the first seal surface 110A to form an angle β with the surface B; Third seal surface 110C in which seal surfaces 110B and 110B are connected to each other. The opening 20 of the valve seat 16 has a predetermined width in the direction of the open axis A-A within the circumference of the first to third seal surfaces 110A, 110B, 110B, and 110C. The seal member 30 is combined with the seal sheet surface 110 to open and close the opening 20. The seal member 30 is composed of integral first to third seal members 30A, 30B, 30B, and 30C, and these seal members are first to third seal surfaces 110A, 110B, 110B, and 110C. Each contact. The valve body 40 moves in the axial direction perpendicular to the plane (B). Therefore, the gate valve can be opened and closed simply by moving the valve body 40 to the state of disengagement with the seal seat surface 110, and the sealed and unsealed state can be achieved. That is, unlike the prior art, the gate valve of the present invention does not have mechanical slide parts, so that no operation delay occurs and no abrasive powder is formed. When the valve is closed, both openings on both sides of the first seal member 30A on the first seal surface 110A are supported by the valve seat 16 by bringing the seal member 30 into close contact. Accordingly, the gate valve of the present invention is free from any irrationality such that the valve body 40 moves due to the pressure difference between the seals on both sides of the valve body, and it is possible to obtain a reliable seal.

Claims (9)

In a vacuum gate valve device having a vacuum passage, a valve casing (60) is disposed in the valve casing (60), the valve body (40) for opening and closing the vacuum passage while reciprocating between two positions, and closing the casing at the same time. A bonnet flange 9 having a ball 11 and a stem shaft 3 which is loosely inserted into the through hole 11 and engages with the valve body 40, and enables the valve body 40 to reciprocate. Driving means (10) disposed on the bonnet flange (9) for driving, guide means (4) for guiding the stem shaft (3) between the two positions, and the guide means (4) from the vacuum passage; Isolating means (4) for isolating, said drive means (10) having reciprocating means (13) for reciprocating the stem shaft (3), said guide means (14) being a bonnet A plurality arranged perpendicular to the surface of the flange (9) Two inner linear shafts 8, a plurality of linear inner bearings 7 slidably guided by the inner linear shafts, and the stem shaft, which are slidably supported by the inner shafts during the linear motion through the inner shaft bearings. A bellows moving flange (5), said isolating means (4) comprising an expandable bellows arranged coaxially with the stem axis, one end of said bellows being fixed to said bonnet flange (9) and the other end of said And a bellows movable flange for enclosing the stem axis. 2. The valve casing of claim 1 wherein the valve casing comprises a valve seat 16, the valve seat 16 comprising an upper surface 110 and an oval seal seat surface, the seal seat surface being the upper surface. The first seal surface 110A tapered inwardly while forming a first predetermined angle α with respect to 110, continuing to the first seal surface 110A, and at the same time, a second predetermined angle with respect to the upper surface 110. A second seal surface 110B having a pair of side surfaces while forming an angle β, a third seal surface 110C for interconnecting the side pairs, and an opening 20 through which the valve seat 16 passes. Vacuum gate valve, characterized in that. 2. The valve body is coupled to the seal seat surface to open and close the opening 20. The valve body is a valve plate 40 coupled to the stem shaft 3, and a first seal integrated with each other. The first seal surface 110A, the second seal surface 110B, and the first seal 30A, the second seal member 30B, and the third seal member 30C include the first seal surface 110A, the second seal surface 110B, and the first seal when the valve is in the closed position. A vacuum gate valve comprising a seal member 30 in contact with each of the three seal surfaces 110C. In a vacuum gate valve, it comprises a valve seat (16), the valve seat (16) comprising an upper surface (110), and an oval seal seat surface, wherein the seal seat surface is relative to the upper surface (110). A second predetermined angle β that is continuous with the first seal surface 110A and the first seal surface 110A that is tapered inwardly while forming the first predetermined angle α, and is constant with respect to the upper surface 110. And a second seal surface 110B having a pair of side surfaces, a third seal surface 110C interconnecting the pair of side surfaces, an opening 20 through which the valve seat 16 passes, and the seal sheet surface. A valve body coupled to open and close the opening 20, and the valve body 40 includes a valve plate 40, a first seal member 30A integrated with each other, a second seal member 30B, and a third seal member. And a sealing member 30 in contact with the first seal surface 110A, the second seal surface 110B, and the third seal surface 110C, including 30C. Vacuum gate valve, characterized in that. 5. The vacuum gate valve according to claim 4, wherein the first predetermined angle [alpha] is equal to the second predetermined angle [beta]. 6. The vacuum gate valve of claim 5, wherein the first predetermined angle [alpha] is about 60 degrees. In the vacuum gate valve device, the vacuum passage is slidably disposed in the valve casing 60, the valve casing 60, and corresponds to a first position corresponding to a closed state of the vacuum passage and an open state of the vacuum passage. A valve body 40 slidably moved between second positions, a bonnet flange 9 having a through hole 11 at the same time closing the valve casing, and a valve body 40 being loosely inserted into and extending into the through hole. It has a stem shaft (3) engaging with the drive means for driving the valve body 40 between the first position and the second position 10, the stem shaft (3) is guided, from the bonnet flange And guide means including at least one guide shaft extending, a bearing slidably coupled to each of the guide shafts, and a movable flange slidably attached to the guide shaft through the bearing, And further comprising an extendable bellows provided coaxially with the stem axis, one end of which is connected to the bonnet flange 9 and the other end connected to a movable flange to isolate the guide means from the vacuum passage. Vacuum gate valve characterized in that. 8. The valve casing of claim 7, wherein the valve casing comprises a valve seat 16, the valve seat 16 comprises an upper surface 10 and a seal seat surface, and the seal seat surface is the upper surface 110. A second predetermined angle relative to the upper surface 110 at the same time continuous to the first seal surface 110A and the first seal surface 110A of an elliptical tapered inward while forming a first predetermined angle α with respect to a second seal surface 110B having a pair of side surfaces while forming β), and a third seal surface 110C for interconnecting the pair of side surfaces, wherein the valve seat 16 opens an opening 20 as a passage. The vacuum gate valve having a. The valve body of claim 8, wherein the valve body is coupled to the seal seat surface to open and close the opening 20, and the valve body is connected to the valve plate 40 and the valve plate 40 coupled to the stem shaft 3. The first seal surface 110A disposed at the same time as the first seal member 30A, the second seal member 30B, and the third seal member 30C, when the valve is in the closed position; And a seal member (30) contacting the second seal surface (110B) and the third seal surface (110C), respectively.