JP2003097735A - Vacuum gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a valve plate support body 20 from following even when inside pressure of a valve box 1 is atmospheric and pressure in the same direction acts on a valve plate 5, in a vacuum gate valve G comprising: the valve box 1 communicating with a vacuum container C1; the valve plate support body 20 that can move between a valve open position and a valve close position in a direction approximately in parallel with an opening 2 of the vacuum container C1 inside the valve box 1; a drive means 31 for moving the valve plate support body 20;, and the valve plate 5 being supported by the valve plate support body 20 in a contacting/detaching manner via a parallel link mechanism 44 having a pair of links 45 and contacting/detaching from the valve plate support body 20 at the valve open position of the valve plate support body 20 for opening/closing the opening 2 of the vacuum container C1. SOLUTION: When pressure in the same direction acts on the valve plate 5 in a state that the valve plate 5 closes the opening 2 of the vacuum container C1, the valve plate 5 is made to move in a relatively closing direction for the valve plate support body 20 by a rear side link shaft inserting hole 45a made of a long hole formed on the links 45.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a technical field of a vacuum gate valve for opening and closing an opening of a vacuum container.

[0002]

2. Description of the Related Art Conventionally, as a vacuum gate valve of this kind, as disclosed in, for example, Japanese Utility Model Laid-Open No. 64-770, a valve plate is supported in a valve box communicating with a pair of adjacent vacuum containers. The body is arranged so that it can be moved up and down while being guided by a guide roller that is axially supported on its back surface, and a communication part between the valve box and one of the vacuum vessels is provided on one side of the valve plate support on the side of the vacuum vessel. A valve plate that opens and closes is supported by a parallel link mechanism so that it can be contacted and separated, and the valve plate comes into contact with the valve plate when the valve plate support descends and moves the valve plate relative to the support in the closing direction. A valve plate stopper is provided, and a cylinder having a piston rod that vertically and vertically penetrates the upper wall of the valve box is attached to the outer surface of the valve box, and the lower end of the piston rod is attached to the valve plate support in the valve box. The valve plate support is moved up and down in the valve box by the expansion and contraction of the cylinder. When the valve plate support is lifted by the contraction of the cylinder, the valve plate is lifted together with the valve plate support to open the communication part with the vacuum container of the valve box, and the two vacuum containers On the other hand, while lowering the valve plate support by the extension operation of the cylinder,
Along the way, the valve plate, which descends together with the valve plate support, is brought into contact with the valve plate stopper to be separated from the valve plate support by the parallel link mechanism, and this separation causes the valve plate to be connected to the valve box and the vacuum container. It is known that the vacuum containers are pressed against each other to cut off communication between the two vacuum containers.

By the way, such a vacuum gate valve is provided with a seal member between the valve plate and the wall portion around the communicating portion for sealing a gap between the valve plate and the wall portion when the valve is closed. Then, by restricting the movement of the valve plate support to a predetermined valve closing position, a predetermined amount of compression is applied to this sealing member to exert the necessary sealing performance.

However, in the above-mentioned conventional device, while the inside of the vacuum container is in a vacuum state when the valve plate is in the valve closing position,
When the inside of the valve box is opened to the atmosphere, a pressure in the direction of closing the valve plate (hereinafter referred to as positive pressure) acts due to the pressure difference between the two, and when this positive pressure presses the valve plate against the valve box, The valve plate support, which is connected to this valve plate by a parallel linkage, is also pulled. Therefore, a bending moment is applied to the base of the piston rod of the cylinder connected to the valve plate support, and the sealing performance and life of the piston sliding part in the cylinder and the part where the piston rod penetrates the valve box in an airtight manner. There was a problem that it decreased.

Therefore, conventionally, it has been proposed to set the capacity of the cylinder so that the seal is compressed to the maximum extent to the extent that the seal is not compressed further in the closed state of the valve plate where positive pressure does not act.

In addition to the above, it has been proposed that the piston rod of the cylinder be made swingable so that no bending moment is applied to the base of the piston rod.

[0007]

However, in the former proposal example, there is a problem that a large driving force is required to compress the sealing member so that the sealing member is in a tightly sealed state, and it is necessary to increase the size of the cylinder. there were. Also,
In the latter proposed example, the amount of movement of the valve plate and the valve plate support does not pose a problem, but there is a problem that the mechanism for making the piston rod oscillate becomes complicated and the cost increase cannot be avoided.

The present invention has been made in view of the above points, and an object of the present invention is to devise a structure for supporting the valve plate on the valve plate support so that a positive pressure is applied to the valve plate. But to prevent the valve plate support from moving.

[0009]

In order to achieve the above object, in the present invention, a valve plate is supported by a valve plate support member so as to be movable relative to each other, and only the valve plate is supported by the valve plate support member when positive pressure is applied. I tried to move it.

Specifically, in the invention of claim 1, between the valve box communicating with the vacuum container and between the valve opening position and the valve closing position in the valve box along a direction substantially parallel to the opening of the vacuum container. A valve plate support that is movable, drive means that moves the valve plate support, and a valve plate that is supported by the valve plate support so as to be able to come into contact with and separate from the valve plate support through a parallel link mechanism having a pair of links. And a valve plate that opens and closes the opening of the vacuum container by contacting and separating from the valve plate support at the valve closing position of the support, and the valve plate is in the closing direction to the valve plate with the opening of the vacuum container closed. It is configured to be movable in the closing direction relative to the valve plate support when the pressure is applied.

According to the above construction, when a pressure (positive pressure) in the closing direction acts on the valve plate when the valve plate is in the valve closing position, the valve plate is closed relative to the valve plate support. When the valve is closed, the sealing member or the like for sealing the gap between the valve plate and the wall portion around the opening of the vacuum container is compressed, and the compression can absorb the pressing force of the valve plate. Therefore, the valve plate support connected to the valve plate by the parallel link mechanism is not pulled simultaneously with the movement of the valve plate. Therefore, the bending moment or the like is not applied to the driving means for moving the valve plate support, and the structure of the driving means can be simplified and the life thereof can be improved. In addition, it is not necessary to set the cylinder capacity so that the seal or the like is compressed to the maximum extent in the closed state of the valve plate where positive pressure does not act, and it is not necessary to increase the capacity of the drive means. Become.

According to the second aspect of the present invention, link shaft insertion holes are provided at both ends of each link of the parallel link mechanism.
One end of this link is swingably supported by the valve plate support member, and the other end is swingably supported by the valve plate via a link shaft inserted into the link shaft insertion hole. The link shaft insertion hole is an elongated hole extending in the link length direction.

According to the above construction, when positive pressure acts on the valve plate when the valve plate is in the valve closing position, the valve plate moves in the closing direction relative to the valve plate support to move the valve by the positive pressure. The sealing member is compressed to such an extent that the pressing force of the plate is absorbed. But,
Since the link shaft insertion hole of the link of the parallel link mechanism that supports the valve plate so that it can be brought into contact with and separated from the valve plate support is a long hole, only the link shaft moves within the long hole. Can be absorbed by the long hole provided in the link, and the valve plate support connected by the parallel link mechanism is not pulled at the same time as the movement of the valve plate. Therefore, the bending moment or the like is not applied to the drive means for moving the valve plate support, and the structure of the drive means can be simplified, the life can be extended, and the size can be reduced.

According to the third aspect of the present invention, the driving means is a cylinder having a piston rod which penetrates the wall portion of the valve box in an airtight manner and whose inner end portion is connected to the valve plate support.

With the above arrangement, the valve plate support connected to the piston rod is moved up and down in the valve box by the expansion and contraction operation of the cylinder to open and close the valve plate, and when the valve plate is in the valve closing position, the valve is closed. Even when positive pressure is applied to the plate, only the valve plate moves in the closing direction relative to the valve plate support, so there is no bending moment applied to the piston rod, and the piston slides in the cylinder. It is possible to prevent a decrease in the sealing performance and the life of the portion and the portion where the piston rod penetrates the valve box. In addition, it is not necessary to set the cylinder capacity so that the seal and the like are compressed to the maximum extent when the positive pressure does not act on the valve plate closed, and it is not necessary to increase the size of the cylinder. .

[0016]

6 and 7 show a vacuum gate valve G according to an embodiment of the present invention. This vacuum gate valve G
The first and second vacuum containers C1 and C2 located at the front and rear are provided so as to connect or disconnect the internal spaces (vacuum spaces) of the vacuum containers C1 and C2.

The vacuum gate valve G includes both vacuum containers C1 and C1.
A rectangular valve box 1 made of, for example, stainless steel or the like is sandwiched between C2 in an airtight manner, and a front wall 1a of the valve box 1 (see FIG.
The left side wall) has a front opening 2 communicating with the first vacuum container C1 and the rear wall 1b (right side wall) having a rear opening 3 communicating with the second vacuum container C2 at the same height. The openings 2 and 3 are formed in a vertical position, and each of these openings 2 and 3 has a rectangular shape that is long in the left-right direction (direction orthogonal to the paper surface of FIG. 7. In the left-right direction in FIG. 6) and has the same size. , 3 through which the space in the valve box 1 becomes the respective vacuum containers C1 and C2.
It communicates with the inside. That is, in this embodiment, the front wall 1a of the valve box 1 constitutes the wall portion of the first vacuum container C1, the rear wall 1b constitutes the wall portion of the second vacuum container C2, and the front opening 2 is the first The first vacuum container C1 constitutes an opening, and the rear side opening 3 constitutes an opening of the second vacuum container C2.

As shown in FIGS. 1 and 7, a valve plate 5 for opening and closing the front opening 2 (opening of the first vacuum container C1) is arranged and housed in the valve box 1. The valve plate 5 is a rectangular plate that is slightly larger than the front opening 2 in the lower portion of the valve box 1 and is long in the left-right direction, for example, a stainless steel plate, and the front outer peripheral surface thereof is continuous over the entire valve plate 5. A seal accommodating groove 6 is formed, and a ring-shaped rubber or resin seal member 7 is accommodated and fixed in the seal accommodating groove 6.

That is, the valve plate 5 has a rear side surface (a right side surface in FIG. 7) having a valve plate support member 2 having substantially the same size as the valve plate 5.
It is supported by 0 through parallel link mechanisms 44, 44, ... Then, the valve plate 5 comes into contact with and separates from the valve plate support 20 at the valve closing position of the valve plate support 20, and opens and closes the front opening 2 to open the first and second vacuum containers C1 and C1.
The two are connected or disconnected. And
When the valve plate 5 closes the front opening 2 of the first vacuum container C1, the valve plate 5 and the wall portion around the front opening 2, that is, the valve box 1
The seal member 7 is compressed between itself and the inner surface of the front wall 1a to seal between the valve plate 5 and the wall portion.

Further, as shown in FIG. 4, roller shafts 9, 9 extending horizontally in the horizontal direction are attached and fixed to the lower ends of the left and right side portions of the front side surface of the valve plate 5, respectively. The plate front roller 10 is rotatably supported.
Further, at the lower ends of the left and right side portions on the inner surface of the front wall 1a of the valve box 1, corresponding to the respective valve plate front rollers 10 when the valve plate 5 is in the valve closed state in which the front opening 2 of the valve box 1 is closed. In the state where the bottomed concave portion 1c is formed and the valve plate 5 opens the front opening 2, the valve plate front roller 10 rolls on the inner surface of the front wall on both the left and right sides of the front opening 2, but in the closed state. The front valve plate roller 10 is adapted to enter the recess 1c of the valve box 1 while floating from the bottom surface thereof.

The valve plate support 20 is provided with a plurality of types of guide rollers 22, 24 and 26 for guiding the valve plate support 20 up and down in the valve box 1. That is, FIG.
As shown in FIG. 2, roller shafts 21 and 21 having horizontal and horizontal axial centers are respectively projectingly attached and fixed to the left and right side portions of the valve plate support 20, and the roller shafts 21 of the valve box 1 are attached to the respective roller shafts 21. Front and rear guide rollers 22 having an outer diameter slightly smaller than the distance between the inner surface of the front wall 1a and the inner surface of the rear wall 1b and rolling on the inner surfaces of the front and rear walls 1a and 1b on the left and right sides of the openings 2 and 3 of the valve box 1. Is rotatably supported.

Further, as shown in FIGS. 1, 2 and 4, the valve plate support 20 on the second vacuum container C2 side (right side in FIG. 7).
The upper and lower end portions of the rear side surface are notches 28,
28, ... Are provided, for example, six each. The cutouts 28, 28 at the upper end are opened in the upper and rearward directions, while the cutouts 28, 28 in the lower end are opened in the lower and the rearward directions. And these notch parts 28 and 2
8, ... Roller shafts 2 extending in the horizontal left and right directions, respectively.
, 23 are mounted and fixed in a state of being aligned in the left-right direction substantially corresponding to the top and bottom, and each of the roller shafts 23 is provided with a rear guide roller 24 capable of rolling on the inner surface of the rear wall 1b of the valve box 1. It is supported. In this rear guide roller 24, the valve plate 5 is the valve box 1
In the valve closing process of closing the front opening 2, the reaction force is deposited on the inner surface of the rear wall 1b to compress the seal member 7.

Further, as shown in FIG. 4 and FIG. 5, roller shafts 25, 25, ... (Only one of which is shown at the upper and lower ends of the left and right side portions of the valve plate support 20 have horizontal and longitudinal axis centers, respectively. ) Is attached and fixed, and side rollers 26 rolling on the inner surfaces of the left and right side walls of the valve box 1 are rotatably supported by the respective roller shafts 25. Then, these guide rollers 22, 2
4 and the side rollers 26 allow the valve plate support 20 to move the valve box 1
It is designed to move up and down in the front-rear direction and the left-right direction with almost no displacement.

In this way, the valve plate support 20 is guided in the valve box 1 by the front and rear guide rollers 22, the rear side guide rollers 24, and the side rollers 26, which serve as a guide mechanism, and the first and second vacuums are provided. Each opening 2, 3 of the containers C1, C2
It is movable between a valve opening position and a valve closing position along a direction substantially parallel to.

Then, as shown in FIGS. 6 and 7, the valve plate support 20 is movably supported by an air cylinder 31 as a driving means disposed in the upper portion of the valve box 1. . That is, the air cylinder 31 is the valve box 1
A piston rod that is arranged and fixed in a state of being mounted on a cylinder base 30 that is fastened and fixed to the upper wall surface of the cylinder rod, projects downward from the cylinder body, and penetrates the wall portion of the valve box 1 in an airtight manner to make a linear motion. 31a. A clevis 33 having a bottom surface portion and a protruding portion 33a extending downward from the bottom surface portion is pivotally supported on the inner end portion of the piston rod 31a so as to be swingable in a vertical plane. And this clevis 3
The valve plate support 20 is connected to the protruding portion 33a of the valve plate 3. Although not shown, the wall of the valve box 1 through which the piston rod 31a penetrates is provided with a sealing mechanism for keeping the inside of the valve box airtight.

In this way, the valve rod support 20 and the valve plate 5 are raised and lowered by raising and lowering the piston rod 31a by the expansion and contraction operation of the cylinder 31. That is, when the cylinder 31 is contracted, the valve plate support 20 and the valve plate 5 are raised to open the gate valve G, while when the cylinder 31 is expanded, the valve plate support 20 and the valve plate 5 are opened. 5 is lowered to close the gate valve G.

As shown in FIG. 1, abutting members 40, 40 are attached to the lower portion of the valve box 1 directly below the valve plate front rollers 10 in a state of being aligned in the left-right direction. . Each of the contact members 40 is a block-shaped member, and when the valve plate support 20 is lowered to the vicinity of the lower end position, it abuts the valve plate 5, more specifically, the valve plate front roller 10, and stops the downward movement of the valve plate 5. Then, as the valve plate support 20 is subsequently moved downward, the valve plate 5 is moved to the parallel link mechanisms 44, 44, ...
Is guided so as to move relative to the front direction, that is, the closing direction, away from the valve plate support 20. Instead of the front valve plate roller 10, a stopper roller that abuts on the valve plate 5 and rolls may be pivotally supported on each contact member 40.

Further, as shown in FIGS. 1 and 5, a block-shaped support member 41 is fixedly provided on the inner bottom of the valve box 1, and the moving direction of the valve plate support 20 is provided on the upper surface of the support member 41. An adjustment shim 42, which is laminated on and integrated with, is placed. Further, a stopper 43 is provided on the upper surface of the adjusting shim 42 so as to come into contact with the valve plate support body 20 at the valve closing position of the valve plate support body 20, and a bolt or the like (see FIG. It is fastened and fixed by (not shown). In this way, by changing the thickness and the number of adjustment shims 42, the contact position of the valve plate support 20 with the stopper 43 is changed, and the compression amount of the seal member 7 is adjusted. .

The parallel link mechanisms 44, 44, ... Are provided between the valve plate 5 and the valve plate support 20, and the valve plate 5 and the valve plate support 20 are in the closed position of the valve plate support 20. Are supported so as to come into contact with and separate from each other, and the vacuum gate valve is opened when the valve plate 5 and the valve plate support 20 are brought into contact with each other, and is closed when separated.

That is, as shown in FIGS. 1 to 3, the valve plate support 20 has a plurality of openings 29, 29, ... They are formed side by side. And each of these openings 2
A substantially cylindrical link shaft 47 is arranged in the shaft 9 with the horizontal left-right direction orthogonal to the moving direction of the valve plate support 20 as the axial center direction. The link shaft 47 has link shaft insertion holes 45 at both ends.
a rear end portion of the link 45 having a and 45b (valve plate support 2
The rear end of the link 45 is supported by the link shaft 47 so as to be swingable about its axis.

A recess 13 is formed on the rear side surface of the valve plate 5 so as to substantially correspond to each opening 29 of the valve plate support 20. A substantially cylindrical link shaft 46 is arranged in each of the recesses 13 with the horizontal left-right direction as the axial center direction, and the front end portion (the end portion on the valve plate 5 side) of each link 45 is attached to the link shaft 46. The front-side link shaft insertion hole 45b is inserted, and the front end of the link 45 is swingably supported around the axis of the link shaft 46. A pair of links 45, 45 corresponding to the upper and lower sides constitute a parallel link mechanism 44, 44, ..., Through which the parallel link mechanism 44, 44 ,. Is supported by a front side surface thereof (a side surface on the first vacuum container C1 side) so as to be capable of contacting and separating.

As a feature of the present invention, the valve plate 5 is
It is configured to be movable in the closing direction relative to the valve plate support 20 when a pressure (positive pressure) in the closing direction acts on the valve plate in a state where the front opening 2 of the vacuum container C1 is closed. Specifically, the link shaft insertion holes 45 at both ends of each link 45 are provided.
Of the a and 45b, the front link shaft insertion hole 45b at the front end portion
Is a circular hole, whereas the rear link shaft insertion hole 45a at the rear end is an elongated hole extending in the length direction of the link 45. The length of this long hole is larger than the amount of movement of the valve plate 5 when a positive pressure acts on the valve plate 5 with the valve plate 5 closing the opening 2 of the vacuum container C1. ing. That is, the length of the long hole is such that the valve plate 5 moves in the closing direction relative to the valve plate support 20 due to the pressure in the closing direction, and the valve plate 5 and the wall portion around the opening 2 (the valve Box 1
When the seal member 7 that seals the gap between the front walls 1a) is compressed, it is longer than the compression amount of the seal member 7. The positive pressure is generated due to the pressure difference between the vacuum chamber C1 and the vacuum chamber C1 which are in a vacuum state and the inside of the valve box 1 is opened to the atmosphere.

Next, the operation of the above embodiment will be described. When the vacuum gate valve G in the closed state shown in solid lines in FIGS. 1 and 6 and in FIG. 7 is opened, the piston rod 31a is moved upward by the contraction operation of the cylinder 31. As a result, the valve plate support 20 connected to the inner end of the piston rod 31a via the clevis 33 is moved to the guide roller 2
2 and 24 ascend in the valve box 1 while being guided in the front-rear direction by the side rollers 26 and in the left-right direction by the side rollers 26. By raising the valve plate support 20,
The valve plate 5 that closes the communication part between the valve box 1 and the first vacuum container C1, that is, the front opening 2 in a gas-tight manner is the parallel link mechanism 4
It is pulled up by 4, 44, ... And the front side opening 2 is opened.

Then, in the vicinity of the contraction stroke end of the cylinder 31, as shown in phantom lines in FIGS. 5 and 6,
The valve plate 5 is moved by the valve plate support 20 so that the lower end portion thereof substantially coincides with the upper end positions of the openings 2 and 3 of the valve box 1, so that the inner spaces of the vacuum vessels C1 and C2 move inside the valve box 1. It becomes a communication state through.

On the other hand, when the gate valve G is closed from the above open state, the piston rod 31a is lowered by the extension operation of the cylinder 31. As a result, the valve plate support 20 moves down in the valve box 1 together with the valve plate 5 while being guided by being restricted by the guide rollers 22, 24 and the side rollers 26. When the valve plate front rollers 10 at the lower end of the valve plate 5 come into contact with the stoppers 40 near the lower end position of the valve plate support 20, further downward movement of the valve plate 5 is stopped, and the valve plate support 20 is stopped. By further descending movement,
The valve plate 5 is moved and guided to the front side so as to be separated from the valve plate support 20 by the standing motion of each link 45 in the parallel link mechanism 44, 44, ... At this time, a reaction force is generated in the valve plate support body 20 by the standing motion of each link 45, and the reaction force is the rear guide roller 2 of the valve plate support body 20.
4 is deposited on the inner surface of the rear wall 1b.

As shown by the solid line in FIG. 6 and FIG. 7, when the lower end of the valve plate support 20 reaches the vicinity of the upper surface of the stopper 43, the seal member 7 provided on the valve plate 5 causes the valve box 1 to move. It contacts the wall surface around the front opening 2 (opening of the first vacuum container C1). Then, the valve plate support 20 whose movement is restricted on the rear side by the guide rollers 22 and 24 is further lowered, so that the valve plate 5 is linked to the link 4 by the valve plate support 20.
It is pushed to the front side through 5, 45, ..., and the compression amount of the seal member 7 is increased. At this time, the link shaft 47 on the valve plate support 20 side is pushed by pushing the inner surface of the valve plate 5 side of the rear link shaft insertion hole 45a formed of a long hole at the rear end of the link 45.
Is pushed to the front side, which pushes the valve plate 5 to the front side via the link shaft 46.

The lower end of the valve plate support 20 contacts the upper surface of the stopper 43 and the valve plate support 20 reaches the closed position, so that the valve plate support 20 stops descending and the seal member 7 is closed. A predetermined amount of compression is applied to, and in this state, the communication between the internal spaces of the vacuum vessels C1 and C2 is blocked by the valve plate 5 in an airtight sealed state.

In this state, when the vacuum container C2 cannot be kept in a vacuum state due to opening or the like, the vacuum container C2
A pressure difference is generated between the inside of the valve box 1 communicating with the vacuum chamber C1 and the inside of the vacuum container C1, and the pressure in the closing direction, that is, the positive pressure acts on the valve plate 5 due to this pressure difference, and the valve plate 5 causes It is pressed against the front wall 1a of the box 1. Such positive pressure causes the valve plate 5 to move in the closing direction while compressing and deforming the seal member 7.

At this time, at the rear end of each link 45 of the parallel link mechanism 44, a rear link shaft insertion hole 45a formed of a long hole is formed.
Since the valve plate 5 is moved due to the compression deformation of the seal member 7, the link shaft 47 on the valve plate support 20 side is relatively moved within the rear link shaft insertion hole 45a formed of an elongated hole. Absorbed by That is, when the valve plate 5 is pushed to the front side, the link 45 supported by the link shaft 46 is pulled to the front side, but since the link shaft 47 can relatively move within the rear side link shaft insertion hole 45a of the link 45, Only the link 45 moves to the front side, and no force acts on the link shaft 47. Therefore, this link shaft 47
The valve plate support 20 integrated with the valve plate does not move to the front side.
As a result, no bending moment is applied to the piston rod 31a of the air cylinder 31 that supports the valve plate support 20, and the piston sliding portion in the air cylinder 31 and the piston rod 31a penetrate the valve box 1. It is possible to prevent the sealing performance and the life of the part to be shortened from being shortened. Therefore, it is not necessary to make the air cylinder 31 swingable, and the structure can be simplified and its life can be improved. Further, it is not necessary to set the capacity of the air cylinder 31 so that the seal 7 is compressed to the maximum extent to the extent that the seal 7 is not further compressed in the closed state of the valve plate 5 where no positive pressure is applied. No need to upgrade.

In the above embodiment, the rear link shaft insertion hole 45a at the rear end of the link 45 is a long hole, but instead of this, the front link shaft insertion hole 45b at the front end of the link 45 is a long hole. Also, the link shaft insertion holes 4 at both ends
Both 5a and 45b may be elongated holes.

Further, the link shaft insertion hole 45 of the link 45
The vacuum container C has a structure other than that in which a long hole is provided in a and 45b.
When the pressure in the closing direction acts on the valve plate 5 with the front opening 2 of 1 closed, the valve plate 5 may be movable relative to the valve plate support 20 in the closing direction. .

Further, in the above embodiment, the valve plate support 20 is provided.
Stopper 43 and adjustment shim 42 to regulate the movement amount of
Is provided, but it is not always necessary to provide these,
The amount of movement of the valve plate support 20 may be regulated by adjusting the stroke of the piston rod 31a.

[0043]

As described above, according to the first aspect of the present invention, the valve box communicating with the vacuum container, and the valve opening position and the valve closing position in the valve box along a direction substantially parallel to the opening of the vacuum container. A valve plate support movable between the positions, a drive means for moving the valve plate support, and a valve plate support supported so as to be able to come into contact with and separate from the valve plate support through a parallel link mechanism having a pair of links. ,
A valve plate which opens and closes the opening of the vacuum container by contacting and separating from the valve plate support at the valve closing position of the valve plate support, and the pressure in the closing direction when the opening of the vacuum container is closed. The valve plate can be moved in the closing direction relative to the valve plate support when the action is performed. Further, according to the invention of claim 2, one end of each link of the parallel link mechanism is swingable through the link shaft inserted into the valve plate support member and the other end of the link plate through the link shaft insertion hole. The link shaft insertion hole of at least one of the links is an elongated hole extending in the link length direction. According to these inventions, a bending moment or the like is not applied to the driving means for moving the valve plate support, so that the structure of the driving means can be simplified and the life thereof can be improved. In addition, it is not necessary to set the cylinder capacity so that the seal or the like is compressed to the maximum extent in the closed state of the valve plate where positive pressure does not act, and it is not necessary to increase the capacity of the drive means. According to the invention of claim 3, the drive means is a cylinder having a piston rod that penetrates the wall portion of the valve box in an airtight manner and has an inner end portion connected to the valve plate support body. It is possible to prevent the sealing performance and the life of the piston sliding portion and the portion where the piston rod penetrates the valve box from being shortened, and it is not necessary to increase the size of the cylinder.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a main part of a vacuum gate valve in a valve closed state.

FIG. 2 is an enlarged cross-sectional view showing a main part of a vacuum gate valve in a valve open state.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a partial cross-sectional view showing a main part of the vacuum gate valve in a valve closed state.

FIG. 6 is a front view showing the entire vacuum gate valve in a closed state.

FIG. 7 is a side view showing the entire vacuum gate valve in a closed state.

[Explanation of symbols]

G vacuum gate valve C1, C2 vacuum container 1 valve box A few openings 5 valve plate 7 Seal member 20 valve plate support 31 air cylinder 44 Parallel link mechanism 45 links 45a Rear side link shaft insertion hole

Claims (3)

[Claims] 1. A valve box communicating with a vacuum container, and a valve plate support member movable in the valve box between a valve opening position and a valve closing position along a direction substantially parallel to an opening of the vacuum container. A driving means for moving the valve plate support and a valve plate support which are supported by a parallel link mechanism having a pair of links so as to be able to come into contact with and separate from the valve plate support at the valve closing position of the valve plate support. A valve plate that opens and closes the opening of the vacuum container by coming into contact with and separating from the support, and the valve plate supports the valve plate when pressure in the closing direction acts on the valve plate with the opening of the vacuum container closed. A vacuum gate valve, which is configured to be movable in a closing direction relative to a body. 2. The vacuum gate valve according to claim 1, wherein a link shaft insertion hole is provided at both ends of each link of the parallel link mechanism, and one end of the link is a valve plate support.
The other end is swingably supported by the valve plate via a link shaft inserted into the link shaft insertion hole, and at least one of the link shaft insertion holes of each link extends in the link length direction. A vacuum gate valve characterized by being configured with holes. 3. The vacuum gate valve according to claim 1 or 2, wherein the drive means is a cylinder having a piston rod that penetrates a wall portion of the valve box in an airtight manner and has an inner end portion connected to the valve plate support body. A vacuum gate valve characterized by being present.