JPH05263966A - Vacuum gate valve - Google Patents

Abstract

PURPOSE:To secure a vacuum gate valve in the vacuum chamber of which no sliding part, imputable to the cause of dusting, is installed. CONSTITUTION:A valve plate 2 set up with a sealant 12 for pressing the sealing surface of the valve seat of a valve box in a vacuum chamber is driven by a stem shaft 3 separated from the outside by means of a bellows 4. The movement of this valve plate 2 is regulated to an up-and-down motion alone this steam shaft 3 and plural pieces of direct-acting guide shafts 8, bearings 7 and a mobile flange 5, and the valve plate 2 is constituted so as to be moved up and down through the stem shaft 3 by a driving means 10 being connected to this stem shaft 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum gate valve provided between the outside and a vacuum chamber or between vacuum chambers.

[0002]

2. Description of the Related Art In semiconductor manufacturing or thin film manufacturing, a work is processed or processed in a vacuum having a high degree of cleanliness. In this vacuum equipment, generally, a work is once loaded into a load lock chamber, and after a predetermined vacuum degree is reached, the work is loaded into a processing chamber or a processing chamber for processing or processing. A gate valve partitions the loading / unloading ports of the load-lock chamber, the processing chamber, and the processing chamber, and each process is processed and processed.

These gate valves are required to have a high degree of sealing and airtightness, and at the same time, it is necessary to avoid dusting and scattering of lubricating oil due to sliding of members and abrasion when the valves are opened and closed. Many vacuum gate valves have been provided for this purpose.

As an example of this, there is a structure as shown in FIGS. In this example, the opening has a circular shape, and the side wall 21a of the airtight chamber 21 is provided with the opening 21b. Inside the opening 21b, a valve seat 22 as shown in FIG. 4 (a) is airtightly fixed and fixed to the inner wall, and penetrates the upper wall 21c immediately above the valve seat 22. Valve plate 2
A closure member 23 is provided which comprises 3a and a drive device 23b.

As shown in FIG. 4 (a), the valve seat 22 has an upper half cylinder portion 22a formed so that the side half of the airtight chamber 21 covers the upper half of the opening 21b. The lower half semi-cylindrical portion 22b, which is the same as the circular opening portion 21b, is formed in the inner half of 21, and the connecting portions of the upper semi-cylindrical portion 22a and the lower semi-cylindrical portion 22b each have an arc shape and the opening portion 21b. Are connected on a plane that includes the center line of.

As shown in FIGS. 4B and 4C, the valve plate 23a which is in contact with the valve seat 22 to open and close the opening 21b has a lower surface on the upper half cylindrical portion 22a of the valve seat 22 and a lower surface. A driving device 23b which has a shape that abuts against the side semi-cylindrical portion 22b, a packing 24 is attached to the abutting surface, and the upper surface is a rod 25 that moves up and down and is provided outside the airtight chamber 21.
It is connected to the.

The valve seat 22 and the lower surface of the valve plate 23a are provided with a pin 22c and a hole 23c which are perpendicular to the axis of the rod 25 so as to face each other. Is configured to support.

FIG. 5 shows a valve plate 2 instead of the pin 22c and the hole 23c as the means for holding the pressure difference in the case of FIG.
Protective edges 23d are provided on the valve plate 23a on both sides of the lower semi-circular portion 3a so as to project from this semi-circle. Correspondingly, a groove is formed in the lower semi-cylindrical portion 22b of the valve seat 22. 22d
Is opened to hold the pressure difference when the valve plate 23a is closed.

FIG. 6 shows a valve plate 23 having a rectangular opening.
Although a has a trapezoidal shape, the method for maintaining the airtightness when closed is the same as that in the case of FIG.

FIG. 7 shows an example of another method in which the opening is rectangular. In this example, two valve rods 33b, which hold the valve element 33a rotatably to some extent, are used as the closing member 33 facing the valve seat 32 inside the valve box 31, and both ends at the lower end of the valve rod 33b. The connecting rod 33c connects the valve rod 33b and the vertical drive device 33d that moves the connecting rod 33c up and down.

The valve rod 33b is supported by a first spherical plain bearing 34 held on the upper end of a bearing support 31a projecting inward from the lower surface of the valve box 31 and a horizontal drive unit 35 under the valve box 31. The lower side is held by the second spherical plain bearing 36.

Incidentally, the first spherical plain bearing 34 and the valve element 33a.
The bellows fixed upper plate 3 is attached to the valve rod 33b between the holding part of
3e is fixed, and a bellows 37 is provided between the valve box 31 and the bottom surface of the valve box 31 to separate the inside of the valve box 31 from the movable parts below the first spherical plain bearing 34.

The operation of this gate valve is such that the horizontal driving device 35 causes the valve element 33a to contact or separate from the valve seat 32 by a circumferential motion about the first spherical plain bearing 34, and when separated, it is vertically moved by the vertical driving device 33d. The opening is opened by moving it and moving it out of the area of the opening, and the opening is closed by the opposite operation.

[0014]

However, the problem common to the above-mentioned examples is that there is a sliding portion inside the vacuum chamber. For example, in the example of FIG. 3, as shown in FIG.
c and the hole 23c slide, the protective edge 23d and the groove 22d slide in the example of FIG. 5, and the example of FIG. 6 is the same as the case of FIG. Since it is necessary to hold the body 33a rotatably to some extent, sliding occurs at this portion. As a result, dust generation from these sliding parts becomes a problem.

An object of the present invention is to solve the above-mentioned problems and to provide a gate valve which does not have a sliding portion which causes dust generation in the vacuum chamber and therefore does not scatter the lubricating oil.

[0016]

In order to solve the above-mentioned problems, a work is transferred between the outside and a load lock chamber or between the load lock chamber and a processing chamber in a semiconductor manufacturing or thin film manufacturing apparatus or the like. In the gate valve provided in the opening between the vacuum chambers having the opening for, corresponding to the valve seat 1 of the valve box 15 provided in the opening 1b on the first side face 1d for closing or opening the opening. And a drive means 10 that moves the valve plate 2 in the vertical direction and does not have a sliding portion in the vacuum chamber.

The valve seat 1 and the valve plate 2 have an upper surface shape in which both ends between two parallel lines are surrounded by an arc 1a, and a lateral shape is a symmetrical symmetrical trapezoidal shape. Among the sealing surfaces with which the plate 2 contacts, the first sealing surface 1c at the upper peripheral edge has a constant inclination angle α with respect to the upper surface, passes through the lower surface from the portion of the arc 1a, and penetrates the center of the opening 1b. The second side surface 1e of the series of second sealing surfaces 1g on the vertical plane perpendicular to the opening axis A has a constant inclination angle with respect to the upper surface, and these first and second sealing surfaces and the second sealing surface The connecting portion between the second side surface 1e and the bottom surface 1f has a curved surface shape that is connected in an arc shape.

The drive means 10 is provided on a bonnet flange 9 provided on the upper surface of the valve box, and the bonnet flange 9 is used to move the valve plate 2 up and down.
Of the stem shaft 3, a moving flange 5 fixed to the upper end of the stem shaft 3, a plurality of linear motion guide shafts 8 for guiding the vertical movement of the moving flange 5, and a vertical movement of the stem shaft 3. The drive means 10 for urging and the bellows 4 coaxially provided so as to surround the stem shaft 3 between the moving flange 5 and the bonnet flange 9 are provided.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural diagram of a valve plate of a gate valve and its driving device of the present invention, and FIG. 2 is a structural diagram of a valve box including a valve seat.
(A) is a side view, (B) is a perspective view of a valve seat portion.

First, the valve box will be described. The valve box 15 is provided with a valve seat 1 on a lower side and an bonnet flange 9 on an upper side with an upper space 15a therebetween, and an opening is formed on a pair of opposed side surfaces. This opening has the same position and size as the opening 1b of the valve seat 1.

The valve seat 1 is provided with a recess 1h from the upper side, and the top surface thereof has an arc 1 at both ends between two parallel lines.
A recess 1h is formed by a first side 1d in the longitudinal direction which is a symmetrical trapezoidal shape in a shape surrounded by a, and a second side 1e and a bottom 1f inclined inward at an inclination angle β on both sides thereof. The opening 1b is formed so as to face both sides of the first side surface 1d.
Has been drilled.

As a sealing surface for contacting the concave portion 1h of the valve seat 1 and the valve plate 2, a first sealing surface 1c at the upper peripheral portion.
Are formed with a constant inclination angle α with respect to the upper surface.
Further, one arc 1a is perpendicular to the opening axis A penetrating the opening 1b and on a plane intermediate between the openings 1b and 1b on both sides.
From the second side face 1e, the bottom face 1f, the second side face 1e on the opposite side to the arc 1a on the opposite side, the second sealing face 1 having a constant width
g is formed.

The connecting portion between the first sealing surface 1c and the second sealing surface 1g and the connecting portion between the second side surface 1e and the bottom surface 1f both form arc-shaped and continuous curved surfaces.
Further, the inclination angles α and β may be the same even if the inclination angles are the same.

Next, the valve plate 2 will be described. This valve plate 2
Is a shape corresponding to the recessed portion 1h of the valve seat 1 described above, and a sealing material 12 is attached to a portion contacting the first and second sealing surfaces 1c and 1g. The valve plate 2 is connected to the drive means 10 on the upper side by loosely fitting the through hole 11 formed in the bonnet flange 9 with the stem shaft 3.

The driving means 10 comprises a reciprocating means 13 and a guide means 14. As the reciprocating means 13, a generally used drive source such as an air cylinder is used.
The guide means 14 includes a plurality of linear motion guide shafts 8 which are vertically implanted in the bonnet flange 9, and the linear motion guide shafts 8.
A movable flange 5 provided via a linear guide bearing 7 slidably held on the stem, and the stem shaft 3 fixed downward at the center of the movable flange 5. A bellows 4 coaxially arranged so as to surround the stem shaft 3 between a fixed flange 6 provided around the through hole 11 and the movable flange 5 forms a stem shaft 3 and an outer sliding portion. Is isolated. In addition,
The upper end of the stem shaft 3 and the drive source are connected by an appropriate structure.

Next, the operation of this gate valve will be described. First, in the open state, the valve plate 2 is pulled up by the reciprocating means 13 into the upper space 15a in the upper half of the valve box 15, and the opening 1b is opened.

In the closed state, the valve plate 2 is moved by the reciprocating means 13.
Is completely housed in the recess 1h of the valve seat 1, and the first and second sealing surfaces 1c, 1g are pressed by the corresponding sealing material 12 of the valve plate 2. In this case, the valve plate 2 does not come into contact with the inner surface of the valve box 15 at all, and the sealing material 12 is also pressed by the first and second sealing surfaces 1c and 1g, but does not slide.

In the operation of the guide means, the stem shaft 3 moves up and down by the operation of the drive means 10. The stem shaft 3 moves up and down in parallel with the linear guide shaft 8 by the moving flange 5 and the linear guide bearing 7. The center line and the moving direction (vertical movement direction) of the valve plate 2 are also regulated, and as a result, the position of the valve plate 2 is also regulated. Therefore, it is possible to prevent the positional displacement of the valve plate 2 due to the pressure difference between the inside and outside when closing.

The bellows 4 coaxially provided so as to surround the stem shaft 3 between the lower surface of the movable flange 5 and the fixed flange 6 fixed to the upper surface of the bonnet flange 9 guides the stem shaft 3 and the guide shaft. As a result, there is no sliding part in the vacuum chamber containing the valve housing 15 since it is completely separated from the sliding part of the means 14.

[0030]

As described above, since the vacuum chamber containing the valve box 15 and the sliding parts of the driving means 10 and the guide means 14 are completely isolated from each other, fine powder such as dust generated from the sliding parts. Does not enter the vacuum chamber, and the gate valve does not cause dust in the vacuum chamber. Further, the movement of the valve plate 2 due to the pressure difference between both openings is smaller than that in the conventional case.

[Brief description of drawings]

FIG. 1 is a structural diagram of a valve plate of a gate valve and a drive device thereof according to the present invention.

FIG. 2 is a structural view of a valve box including a valve seat, (a) is a side view,
(B) is a perspective view of a valve seat portion.

FIG. 3 is a sectional view of an example of a conventional gate valve having a circular opening.

4 is a perspective view of a valve seat and a valve plate of the gate valve of FIG.
(A) is a view of the valve seat from the outside, (B) is a view of the valve plate from the inside, and (C) is a view of the same from the outside.

5 is a cross-sectional view of a modified gate valve of FIG.

FIG. 6 is a cross-sectional view of an example of a conventional gate valve having a rectangular opening, (a) being a view seen from the inside of the opening, (b).
FIG. 6 is a view seen from the side of the opening.

FIG. 7 is a cross-sectional view of another example of a conventional gate valve having a rectangular opening, (a) being a view seen from the inside of the opening;
(B) is the figure seen from the side of the opening.

[Explanation of symbols]

 1 Valve Seat 1a Arc 1b Opening 1c First Sealing Surface 1d First Side 1e Second Side 1f Bottom 1g Second Sealing 1h Recess 2 Valve Plate 3 Stem Shaft 4 Bellows 5 Moving Flange 6 Fixed Flange 7 Linear Motion Guide Bearing 8 Linear motion guide shaft 9 Bonnet flange 10 Driving means 12 Sealing material 13 Reciprocating means 14 Guide means 15 Valve box

Claims (1)

[Claims] 1. An opening between vacuum chambers having an opening for transferring a work between the outside and a load lock chamber or between the load lock chamber and a processing chamber in a semiconductor manufacturing or thin film manufacturing apparatus or the like. In the gate valve provided in, the valve plate corresponding to the valve seat of the valve box having the opening on the first side surface for closing or opening the opening, and moving the valve plate in the vertical direction and vacuuming. The valve seat and the valve plate have a top surface shape in which both ends between two parallel lines are surrounded by an arc, and a side surface shape is a symmetrical trapezoidal shape. None, among the corresponding sealing surfaces of the valve seat and the valve plate, the first sealing surface of the upper peripheral portion has a constant inclination angle with respect to the upper surface, and passes from the arc portion through the lower surface to the center of the opening. The second of a series of second sealing surfaces on a plane perpendicular to the through-opening axis The side surface has a certain inclination angle with respect to the upper surface, and the connecting portion between the first and second sealing surfaces and the second side surface of the second sealing surface and the bottom surface has a curved surface shape connected in an arc shape, The drive means is provided on a bonnet flange provided on the upper surface of the valve box, and is fixed to the stem shaft into which the bonnet flange is loosely fitted in order to move the valve plate up and down, and the upper end of the stem shaft. A moving flange, a plurality of linear guide shafts for guiding the vertical movement of the moving flange, reciprocating means for moving the stem shaft up and down, and a coaxial shaft surrounding the stem shaft between the moving flange and the bonnet flange. It is equipped with the bellows provided in.