JP7680942B2 - High temperature gate valve - Google Patents

Description

The present invention relates to a high-temperature gate valve, and in particular to a high-temperature gate valve that is highly durable even at high temperatures, ensures stable opening and closing operations, and can be made compact.

Conventionally, in semiconductor manufacturing equipment, vacuum gate valves equipped with long rectangular valve bodies are used as gate valves for opening and closing the wafer transport passageway leading to the vacuum chamber. Between the sealing member of this valve body and the sealing surface, so-called non-sliding type gate valves are known that prevent particle generation from the sealing material due to twisting, sliding, or impact when opening and closing.

In recent years, the process temperature of wafers in film deposition equipment used to manufacture semiconductors and other products has been increasing, and when the process chamber is heated to around 250°C, the gate valve used to separate the process chamber and transfer chamber must also be able to withstand high temperatures.

Gate valves equipped with heaters are also known as a countermeasure against high temperatures. Conventional heater-heated gate valves use perfluoroelastomer material for the seal material of the valve body, and when used at high temperatures, the seal material of the valve body thermally expands, causing overload, increasing vibration and noise when opening and closing, and reducing the durability of the seal material. Therefore, conventional gate valves are not adequately equipped to withstand high temperatures.

The conventional gate valve in Patent Document 1 uses a resin material for the valve body seal, and has a structure in which the valve body is attached to the tip of a stem, and the stem is tilted to press the valve body against the sealing surface of the body to form a valve-closed seal.

The gate valve in Patent Document 2 has a pair of first and second valve plates on a valve body drive body, the first valve plate moves to the first opening side of the valve box to perform the valve closing function, and the first valve plate is provided with a second valve plate that can move to the second opening side via a bellows, and when a back pressure differential occurs that acts in a direction to move the first valve plate away from the valve seat, the bellows expands and the second valve plate abuts against a stopper on the second opening side of the valve box.

JP 2020-56498 A Patent No. 3425937

However, the gate valve in Patent Document 1 does not provide any measures to deal with thermal expansion of the valve body's sealing material at high temperatures. As a result, because the valve is closed by tilting the stem and pressing the valve body against the body's sealing surface, the tilted position of the stem is fixed when the valve is closed, and when the valve body's sealing material thermally expands at high temperatures, there is no escape route to absorb the thermal expansion, and the excessive load pushing back against the stem increases vibration and noise when opening and closing, reducing the durability of the sealing material. There is also the problem of particles being generated from the valve body's sealing material when an overload acts on it.

In Patent Document 2, the valve body driver is structured so that only the first valve plate on one side opens and closes, bending the stem to close and seal the valve, while the second valve plate on the back side is supported by a stopper.If the gap or deviation between the body and the stopper is large, the amount of bending of the stem increases, and if the stem tilts in the opposite direction to the sealing surface, the valve closing performance decreases.
Furthermore, the valve plate on the rear side does not have a displacement suppression member (such as a tension plate) for suppressing bending of the stem, nor a cushion made of PTFE or the like that has small elastic deformation, so the stopper cannot release the thermal expansion of the seal member of the valve body. Therefore, even with the structure of Patent Document 2, there is no countermeasure when the thermal expansion of the seal member of the valve body occurs.

In addition, semiconductor devices that include this type of gate valve are configured with multiple chambers integrated around the transfer chamber, and to make the entire device more compact, the high-temperature gate valve also needs to be made more compact.

The present invention was developed to solve the problems of the past, and its purpose is to provide a high-temperature gate valve that can be opened and closed stably even for high-temperature use, in particular, does not generate overload due to thermal expansion of the sealing material of the valve body, and minimizes vibration and noise when opening and closing the valve, and is also compact.

In order to achieve the above object, the invention according to claim 1 is a high-temperature gate valve comprising a drive shaft that moves up and down within the body, a valve body driver that is attached to the drive shaft and moves horizontally relative to the drive shaft, a horizontally long valve body with a packing made of an elastic material that seals the inner wall surface of the opening of the body on one side of the valve body driver, and a horizontally long tension plate with a cushion made of an elastic material that presses against the wall surface of the body on the other side of the valve body driver, the packing and the cushion being formed in a shape that causes approximately equal deformations to the amount of deformation caused by the tightening load of the valve body by the valve body driver.

The invention of claim 2 is a high-temperature gate valve in which the tension plate, packing, and cushion are formed with contact areas such that the amount of deformation when the valve is closed at high temperatures is approximately the same.

The invention according to claim 3 is a high-temperature gate valve in which the body has a first opening and a second opening that are elongated in the thickness direction, and recesses are formed on the inner wall of the body in the horizontal movement area and the vertical movement area of the tension plate within the body, so that the thickness width of the body other than the recesses is not changed.

The invention according to claim 4 is a high-temperature gate valve in which the cushions provided above and below the tension plate surface are braced against the upper and lower surfaces of the inner wall of the second opening of the body.

The invention according to claim 5 is a high-temperature gate valve in which the valve body driver is structured with a link block attached to the drive shaft, a link mechanism attached to the link block, and a piston in the link mechanism that operates when the drive shaft moves up and down.

The invention according to claim 6 is a high-temperature gate valve in which an output shaft that moves up and down by an actuator is attached to a drive shaft plate provided at the lower end of multiple drive shafts, and a constant load unit with a constant load spring is provided on this output shaft, and at high temperatures, the packing and cushion expand to push down the drive shaft and compress the constant load spring, preventing the application of excessive load.

According to the invention of claim 1, the high-temperature gate valve comprises a drive shaft that moves up and down inside the body, a valve body drive body that moves horizontally relative to the drive shaft, a horizontally long valve body with a packing made of an elastic material that seals the inner wall surface of the opening of the body on one side of the valve body drive body, and a horizontally long tension plate with a cushion made of an elastic material that presses against the wall surface of the body on the other side of the valve body drive body. When the inner wall of the body is sealed as a valve seat by the valve body drive body, the valve body packing and the tension plate cushion are shaped so that they deform by approximately the same amount due to the tightening load of the valve body. This allows the valve to be opened and closed in a stable state without tilting the valve body, and in the valve closed state, the amount of deformation of the valve body packing and the amount of deformation of the cushion are the same, and the pressing force on both sides is approximately the same, so that bias is less likely to occur when the valve is tightened, and the valve closed state can be stabilized.

The valve body driver has a double-opening structure that can be driven horizontally, so it does not become eccentric or tilted. This prevents the valve body or tension plate from hitting the inner wall surface of the body during valve opening and closing operations, eliminating vibrations and noise during valve opening and closing operations at high temperatures.

In addition, if thermal expansion occurs due to high temperatures, for example when the valve body's packing thermally expands due to high temperatures from the chamber, the tension plate cushion absorbs the displacement caused by the thermal expansion of the valve body and relieves the load caused by the thermal expansion, eliminating the occurrence of overload on the valve body's packing due to thermal expansion, reducing wear on the packing and increasing durability.

In addition, the valve body attached to the valve body driver is formed in a long shape, and the tension plate attached to the valve body driver is formed in a short shape, and the tension plate is smaller than the valve body. This avoids the need to make the valve body driver larger, and allows the use of a body width that is approximately the same as the width of a conventional valve body, making the body more compact.

According to the invention of claim 2, the contact area of the packing and the cushion is set so that the amount of deformation when the valve is closed at high temperatures is the same. Therefore, the pressure pressing against the inner walls of the openings on both sides of the body is equalized at both openings, making it easier to stabilize the valve closed state.

According to the invention of claim 3, the body has a first opening and a second opening that are elongated in the thickness width direction, and recesses are formed in the inner wall of the body in the horizontal movement area and the vertical movement area of the tension plate within this body, and the thickness width of the body other than the recesses is not changed to ensure the strength of the valve body. Therefore, by forming a recess on the inner wall side of the body that is pressed by the tension plate that does not seal the opening of the body, the thickness is reduced, while the thickness of other parts of the body is not changed, and the strength of the body can be maintained and made compact.

According to the invention of claim 4, the cushions are provided above and below the tension plate surface and are structured to brace against the upper and lower surfaces of the inner wall of the second opening of the body, and the inner wall of the recess with which the tension plate abuts is made the thinnest, reducing the overall thickness of the body to the minimum necessary, thereby avoiding an increase in the size of the body and achieving a compact design.

According to the invention of claim 5, the vertical movement of the drive shaft moves the link block attached to the drive shaft up and down, and the link mechanism attached to the link block is operated to move the piston horizontally, and the valve body driver is moved horizontally relative to the drive shaft, thereby allowing the valve body to move horizontally in a stable state while maintaining its vertical orientation. Therefore, the high-temperature gate valve does not need to tilt the valve body, and the valve can be opened and closed in a stable state.

According to the invention of claim 6, a constant load unit having a constant load spring and a drive shaft plate are attached to the output shaft of the actuator, and the lower end of the drive shaft is connected to the drive shaft plate attached to the output shaft. Therefore, when the packing or cushion thermally expands at high temperatures, the drive shaft is pushed down via the link mechanism of the valve body drive body, compressing the constant load spring of the constant load unit. This compression of the constant load spring can prevent overloading of the packing or cushion. This reduces wear of the packing or cushion at high temperatures, improves durability, and suppresses particle generation from the packing or cushion.

1 is a vertical sectional front view showing a high-temperature gate valve according to the present invention in a valve closed state. FIG. FIG. 2 is a vertical sectional front view showing the high-temperature gate valve in an open state. 3A is a plan view of the gate valve with a portion thereof omitted, and FIG. 3B is a partially cutaway rear view of the gate valve in a valve closed state. 4A is an explanatory diagram of a constant load unit and a drive shaft plate, and FIG. 4B is an explanatory diagram of the constant load unit in a valve open state and a valve closed state. FIG. 2 is an explanatory diagram of a valve body driver of the high temperature gate valve according to the present invention. 5A is an explanatory diagram of the link mechanism of the valve body driver, FIG. 5B is an explanatory diagram of the valve body driver in the valve open position with the main part of part A in FIG. 5 enlarged, and FIG. 5C is an explanatory diagram of the valve body driver in the valve closed position with the main part of part A in FIG. 5 enlarged. 1A is a diagram illustrating the amount of deformation of a packing when a valve disc is closed, and FIG. 1B is a diagram illustrating the amount of deformation of a cushion when a valve disc is closed. 3A and 3B are explanatory diagrams of the valve opening and closing operation of the high-temperature gate valve according to the present invention, in which FIG. 3A is an explanatory diagram of a valve closed state, and FIG. 3B is an explanatory diagram of a valve open state.

An embodiment of a high-temperature gate valve according to the present invention will be described in detail with reference to the drawings. Figure 1 is a vertical sectional front view of the valve in a closed state. Figure 2 is a vertical sectional front view of the valve in an open state.

The high-temperature gate valve of the present invention is used as a gate valve to open and close the wafer transport passage leading to the vacuum chamber in semiconductor manufacturing equipment. It is a high-temperature gate valve that is highly durable even at high temperatures, ensures stable valve opening and closing operation, and can be made compact.

The high temperature gate valve of this embodiment is configured so that the valve can be closed and sealed in the horizontal direction by horizontally moving the valve element driver 3 relative to the drive shaft 21 without tilting the valve element 5 .
In this example, the link mechanism 4 of the valve body driver 3 connected to the drive shaft 21 that moves up and down inside the body 2 is operated to bring the valve body 5 into contact with or away from the sealing surface (or valve seat) of the opening of the body 2, thereby bringing the high-temperature gate valve into a valve closed or valve open state.

As shown in FIG. 5, the valve body driver 3 is composed of a valve body 5 that seals the inner wall surface of the body 2 as a valve seat, a valve body mounting plate 6 for mounting the valve body 5, a tension plate 7 that presses the inner wall of the body 2 on the opposite side of the valve body 5, a pair of link mechanisms 4 that move the valve body driver 3 horizontally, a bellows 10 that separates the inside and outside of the valve body driver 3, and a bearing 11 that assists the movement of the piston 13 of the link mechanism 4.

The lower end of the valve body driver 3 is connected to a drive shaft 21 , and the valve body driver 3 can move up and down within the body 2 by the up and down movement of the drive shaft 21 via an actuator 40 .
In this example, the valve body driver 3 is configured such that when the drive shaft 21 is raised to a predetermined position, the link mechanism 4 is activated and the piston 13 of the link mechanism 4 causes the valve body driver 3 to move horizontally.

When the link mechanism 4 is activated, the valve body driver 3 moves only horizontally, so the valve body driver 3 does not become eccentric or tilted. This prevents the valve body 5 and tension plate 7 from hitting the inner wall surface of the body 2 during the valve opening and closing operation, and suppresses the generation of vibrations and noise during the valve opening and closing operation at high temperatures.

A horizontally long metallic valve body 5 is provided on one side of both sides of the valve body driver 3. The valve body 5 has a packing 8 made of an elastic material that seals the inner wall surface of the opening of the body 2 as a valve seat. The packing 8 is brought into close contact with the inner wall surface of the opening of the body 2 to seal the first opening 16 closed, and the high-temperature gate valve is put into a closed state.

The packing 8 in this example is made of an elastic member made of a resin material such as perfluoroelastomer (FFKM) or fluororubber (PTFE, etc.), and there are no particular limitations as long as it has a certain degree of durability and heat resistance even when used at high temperatures.

The valve body driver 3 is also provided with a metal valve body mounting plate 6 for mounting the valve body 5, and a heater (not shown) can be attached as desired.

On the other side of both sides of the valve body driver 3 (opposite the valve body 5), a metal tension plate 7 with a horizontally long, short shape is provided, and the tension plate 7 is configured to be large enough not to completely seal the second opening 17 of the opposing body 2.

The tension plate 7 provided on the opposite side of the valve body 5 has a lateral length that is shorter than the lateral length of the valve body 5, and in this example is approximately half that, as shown in Figures 3(a) and (b).

In this example, the tension plate 7 is smaller than the valve body 5, which avoids the valve body driver 3 having a double-opening structure becoming too large. This makes it possible to use a body width that is approximately the same as that of a conventional valve body, making the body more compact.

The tension plate 7 has a cushion 9 made of an elastic material that presses against the wall surface of the body 2. In this example, the cushion 9 is made of an elastic material made of a resin material such as perfluoroelastomer (FFKM) or fluororubber (PTFE, etc.), and there are no particular limitations as long as it has a certain degree of durability and heat resistance even when used at high temperatures.

As shown in Figures 3 and 5, the cushions 9 are provided above and below the tension plate 7, and are structured to brace against the upper and lower surfaces of the inner wall of a recess 19 of the body 2 (described later) on the side of the second opening 17 avoiding the bonnet mounting hole of the body 2, so that only the upper and lower cushions 9 press against the inner wall surface of the recess 19 of the body 2, making the inner wall of the recess 19 that the cushion 9 of the tension plate 7 abuts against the thinnest. By reducing the thickness of the entire body to the minimum necessary, it is possible to avoid increasing the size of the body and to make the high-temperature gate valve more compact.

The cushion 9 is configured to press against and come into contact with the wall surface of the body 2 when the high-temperature gate valve is in the closed state, but because the structure does not completely seal the second opening 17 of the body 2, even if the cushion 9 of the tension plate 7 presses against the inner wall of the second opening 17 when the valve body driver 3 moves horizontally by the link mechanism 4, the second opening 17 remains open.

Here, as shown in Figures 7(a) and (b), the cross-sectional shape of the packing 8 of the valve body 5 and the cross-sectional shape of the cushion 9 of the tension plate 7 are different, and in this example, when the valve body 5 is tightened, the deformation amount V1 of the packing 8 of the valve body 5 and the deformation amount V2 of the cushion 9 of the tension plate 7 are made to be approximately the same.

The horizontal movement of the valve body 5 and tension plate 7 by the link mechanism 4 is the same, so the widths of the deformed portions a1 and a2 shown in FIG. 7 are the same. As described above, the lateral length of the valve body 5 and the lateral length of the tension plate 7 are different, and since the valve body 5 is long while the tension plate 7 is short, the deformed portion b2 of the cushion 9 is made larger than the deformed portion b1 of the packing 8 of the valve body 5, so that the deformation amounts V1 and V2 are the same when the valve body is tightened.

That is, in this example, the packing and the cushion are formed with contact areas such that the amounts of deformation when the valve is closed at high temperatures are approximately the same.
Here, the contact area means the area where the packing 8 of the valve body 5 comes into contact with the inner wall of the first opening 16 when the packing 8 is in pressing contact with the inner wall when the valve is closed, and also means the area where the cushion 9 of the tension plate 7 comes into contact with the inner wall of the second opening 17 when the valve is closed.

The size of the ground contact area (contact area) can be set appropriately so that the deformation amount V1 and the deformation amount V2 are the same, and can be set appropriately taking into account the elasticity of the packing 8 and the cushion 9 and the valve closing performance.
Furthermore, if the packing 8 and the cushion 9 are made of the same material, they will have the same elastic force, which is preferable since it will be easier to set the cross-sectional shape and the contact area.

In this way, when the valve body 5 and the tension plate 7 abut against the openings on both sides of the body 2 by the link mechanism 4, the deformation amount V1 and the deformation amount V2 are the same, and therefore the horizontal movement amount is also the same, and the movement amount of the valve body 5 and the tension plate 7 on both sides can be made approximately the same. Then, when the gasket 8 of the valve body 5 abuts against the inner wall surface of the first opening 16 of the body 2 to tighten the valve body 5 and close the valve, at the same time the cushion 9 of the tension plate 7 also presses against the inner wall of the second opening 17 of the body 2, so that the link mechanism 4 moves the valve body drive body 3 horizontally and opens and closes the valve by bracing both sides, so that the left and right movement amounts on both sides are the same and the pressing force on both the left and right sides is approximately the same, eliminating any bias and resulting in stable valve opening and closing operation even at high temperatures.

In this example, the valve body driver 3 is moved horizontally by the link mechanism 4, but the drive mechanism for moving the valve body horizontally may be a mechanism other than the link mechanism, for example, the valve body may be moved horizontally by a cylinder mechanism.
The link mechanism of this embodiment is merely an example, and will be described below as an example of an embodiment.

The link mechanism 4 of the valve body driver 3 in this example is a pair of V-shaped link mechanisms, and the pair of link mechanisms 4 are simultaneously operated by the up and down movement of a pair of drive shafts 21, causing the valve body driver 3 to move horizontally and open and close the valve. As shown in Figures 5 and 6(a), the link mechanism 4 is composed of a link block 15 connected to the drive shafts 21, a pair of links 12 connected to the link block 15 via shafts 14, and a piston 13 and bearing 11 that move horizontally via the links 12.

The lower end of the link block 15 of the link mechanism 4 is connected to the drive shaft 21, and as the drive shaft 21 moves up and down, the link mechanism 4 is activated and the up and down displacement of the link block 15 is converted into horizontal movement by the link 12, causing the piston 13 to move horizontally, thereby enabling the valve body driver 3 to move horizontally, the valve body 5 to move horizontally toward the first opening 16, and at the same time, the tension plate 7 to move horizontally toward the second opening 17.
That is, the valve body 5 contacts and moves away from the first opening 16 due to the horizontal movement of the piston 13 connected to the link 12 of the link mechanism 4, and the tension plate 7 contacts and moves away from the second opening 17 due to the horizontal movement of the piston 13 connected to the link 12 of the link mechanism 4, thereby turning the high-temperature gate valve into a closed or open state.

The lower end of the link block 15 is provided so that the valve body driver 3 can be engaged with an engaging portion 23 of the center guide 22 when the valve is in the open position.
In the valve open position of Figure 6(b) described below, the locking portion 23 of the center guide 22 engages with the link block 15, and in the valve closed position of Figure 6(c), the engagement between the locking portion 23 of the center guide 22 and the link block 15 is released.

A piston 13 moves horizontally on the inner circumference of the bearing 11, and a bellows 10 is provided on the outer circumference of the bearing 11 to prevent foreign matter from entering between the link mechanism 4 of the valve body driver 3 and the body 2.

The body 2 has a first opening 16 that is elongated in the thickness-width direction and a second opening 17 that is elongated in the thickness-width direction. When the gasket 8 of the valve body 5 abuts against the inner wall of the first opening 16 of the body 2, the valve is sealed closed, and even if the cushion 9 of the tension plate 7 presses against the inner wall of the second opening 17 of the body 2, the second opening is configured to remain open.

A double-opening structure would require a larger valve body driver, which would increase the thickness of the body, but in this example, the inner wall of the body that presses against the tension plate is made as thin as possible to avoid making the body larger.

As shown in Figure 3 (a), a concave recess is formed on the side of the second opening 17 of the central body 2, avoiding the mounting hole of the bonnet 18, and a recess 19 is provided on the inner wall side of the body 2 corresponding to the horizontal movement area and the vertical movement area of the tension plate 7.
Here, the horizontal movement area of the tension plate 7 refers to the area within which the tension plate 7 moves horizontally due to the link mechanism 4. The vertical movement area of the tension plate 7 refers to the area within which the tension plate 7 moves up and down due to the vertical movement of the valve body driver 3 when the drive shaft 21 moves up and down.

A thin plate-like divided body wall 20 is provided in the recess 19, and the divided body wall 20 is made as thin as possible so that the cushion 9 can abut against it, and the inner wall of the recess 19 of the body 2 where the cushion 9 of the tension plate 7 abuts is made as thin as possible. This makes it possible to reduce the overall thickness of the body to the minimum necessary, avoiding an increase in the size of the body and making the high-temperature gate valve more compact.

In addition, as shown in FIG. 3(a), the thickness of the body width is not changed except for the central recess of the body 2, maintaining the thickness and ensuring a certain level of strength.

As shown in FIG. 5, there is a predetermined gap D1 between the inner wall of the body 2 on the first opening 16 side and the valve body 5, and there is a predetermined gap D1 between the inner wall of the body 2 on the second opening 17 side and the tension plate 7. The predetermined gap D1 prevents the packing 8 of the valve body 5 and the cushion 9 of the tension plate 7 from contacting the inner wall of the body 2 when the valve body driver 3 moves up and down vertically within the body 2.

The gap D1 is not particularly limited, but if it is set to about 1 mm, for example, the body 2 can be made compact while preventing the packing 8 and cushion 9 from sliding against the inner wall of the body 2 when the valve body driver 3 moves up and down.

The drive shaft 21 is provided so as to be vertically movable within the stem member 24 via the vertical movement of the output shaft 43 of the actuator 40. In this example, the valve body driver 3 is configured to be vertically movable within the body 2 by the vertical movement of the two drive shafts 21, and a pair of link mechanisms 4 of the valve body driver 3 are provided so as to be operable.
The lower end of the stem member 24 and the support member 26 are isolated from the outside by a bellows 25 .

As shown in FIGS. 6B and 6C, a center guide 22 is provided on the tip side of the drive shaft 21, and a predetermined gap D2 is formed between the center guide 22 and the drive shaft 21.
The center guide 22 guides the drive shaft 21 so as to center its vertical movement, preventing eccentricity, distortion, and rattle when the drive shaft 21 moves up and down, and stabilizes the vertical movement of the valve body driver 3, enabling the link mechanism 4 to open and close the valve in a stable state. In addition, the stable vertical movement of the drive shaft 21 prevents the packing 8 of the valve body 5 and the cushion 9 of the tension plate 7 from contacting the inner wall of the body 2.

The tip of the center guide 22 is provided with a locking portion 23 that can engage with the lower end of the link block 15. When the valve element driver 3 is in the valve open position of Fig. 6(b), the locking portion 23 of the center guide 22 engages with the lower end of the link block 15, and when the valve element driver 3 is in the valve closed position of Fig. 6(c), the engagement between the locking portion 23 of the center guide 22 and the link block 15 is released.
As a result, when the valve body driver 3 is in the valve open position of Figure 6 (b), the movement of the drive shaft 21 is restricted and the position is fixed, and when the valve body driver 3 is in the valve closed position of Figure 6 (c), the drive shaft 21 is able to move slightly and can bend slightly by the amount of gap D2.

In this example, the locking portion 23 of the center guide 22 is formed in a tapered shape, and the lower end of the link block 15 is also tapered to engage with it, but there is no particular limitation. For example, the locking portion 23 of the center guide 22 may be formed in a stepped shape to engage with it.

The lower end of the drive shaft 21 is connected to a drive shaft plate 33 which is linked to an output shaft 43 of an actuator 40 , and a valve opening spring 34 is provided between the drive shaft plate 33 and the guide plate 32 .
When the guide plate 32 rises to a predetermined position, it abuts against the stopper member 31 to limit its rise, and when the output shaft 43 rises further, the valve-opening spring 34 is compressed.
The constant load unit 35 and the drive shaft plate 33 are attached to an output shaft 43 of an actuator 40 .

In addition, a guide member 37 is provided to integrate the up and down movements of the guide plate 32, drive shaft plate 33, constant load unit 35, and drive shaft 21. The integrated up and down movements of the guide plate 32, drive shaft plate 33, constant load unit 35, and drive shaft 21 stabilize the up and down movement of the drive shaft 21, enabling the valve to be opened and closed in a stable state.

As shown in Figures 4(a) and (b), four constant load springs 36 are housed between the constant load unit 35 and the drive shaft plate 33. The constant load springs 36 of the constant load unit 35 are provided so that they can apply the load required to close the valve. When the high temperature gate valve is in the valve closed state, the biasing force of the constant load springs 36 is transmitted in the valve closing direction to the valve body 5 via the valve body driver 3 connected to the drive shaft 21 and the link mechanism 4, thereby maintaining the valve closed state.

In addition, when the valve body 5 is heated to a high temperature and thermal expansion occurs in the packing 8, the cushion 9 is compressed by the thermal expansion, and the link mechanism 4 of the valve body driver 3 pushes down on the drive shaft 21, and the constant load spring 36 is compressed by the load from the direction of the drive shaft 21, and the compression α of the constant load spring 36 absorbs the overload of the packing 8 of the valve body 5.

In this example, a spiral spring is used for the constant load spring 36, but a leaf spring or other spring member may also be used. There is no particular limit to the number or resilience of the constant load springs 36 as long as they can perform the above functions, and they can be set as desired.

In this embodiment, the actuator 40 for moving the drive shaft 21 up and down is configured by a pneumatic actuator, and the air cylinder 41 is provided with a locking means 46 of a latch lock mechanism using a lock pin.
When air is supplied from an external air supply means through an air supply/exhaust passage 45 to the cylinder chamber 44 and the piston 42 rises, the output shaft 43 rises, and the drive shaft 21 rises.

When the piston 42 reaches a predetermined position, the position of the piston 42 is fixed by a locking means 46. Since the piston 42 is fixed when in the valve closed position, the valve closed state can be maintained even if the supply and exhaust of air from the outside is stopped.
Although the locking means 46 in this embodiment is a latch lock mechanism, other methods may be used. For example, the locking means 46 may be configured by a method that restricts the up and down movement of the output shaft 43 of the actuator.

Next, the valve opening/closing operation and the function of the high temperature gate valve according to the present invention will be described.
8A and 8B are diagrams illustrating the valve opening and closing operations of the high-temperature gate valve according to the present invention, where (a) is an explanatory diagram of the valve closed state, and (b) is an explanatory diagram of the valve open state.

To close the high-temperature gate valve of this example, air is supplied from the air supply and exhaust passage 45 to the cylinder chamber 44 of the air cylinder 41 by an external air supply means (not shown), causing the piston 42 of the air cylinder 41 to rise. The rise of the piston 42 causes the output shaft 43 of the actuator 40 to rise, which in turn causes the drive shaft 21 connected to the drive shaft plate 33 to rise.

In this example, when the drive shaft 21 rises, it is guided while being centered by the center guide 22, so that the drive shaft 21 is prevented from becoming eccentric or distorted, and the valve body driver 3 connected to the drive shaft 21 can rise to the valve closed position while maintaining a vertical posture.

When the guide plate 32 rises to a predetermined position, it comes into contact with the stopper member 31, restricting the rise of the guide plate 32. When the output shaft 43 rises further from this state, the valve-opening spring 34 is compressed by the rise of the drive shaft plate 33.
When the drive shaft 21 rises to a predetermined valve-closed position due to the rise of the output shaft 43, the link mechanism 4 of the valve body drive body 3 is actuated. At this time, the piston 42 of the air cylinder 41 is fixed in position by the locking means 46.

When the drive shaft 21 rises to the valve closed position, the upward displacement of the link block 15 of the link mechanism 4 of the valve body drive body 3 is converted to a horizontal direction via the link 12, the piston 13 moves horizontally, the valve body mounting plate 6 connected to the piston 13 moves horizontally, and the valve body 5 attached to the valve body mounting plate 6 moves horizontally toward the first opening 16. When the packing 8 of the valve body 5 moves horizontally until it abuts against the inner wall surface of the body 2, the first opening 16 of the high temperature gate valve is sealed, and the high temperature gate valve is in a valve closed state.

At the same time, the upward displacement of the link block 15 of the link mechanism 4 is converted to a horizontal direction via the link 12 on the second opening 17 side, the piston 13 on the second opening 17 side moves horizontally, the tension plate 7 connected to the piston 13 moves horizontally toward the second opening 17, and the cushion 9 of the tension plate 7 abuts against the inner wall of the body 2, and the cushion 9 presses against the inner wall of the body 2 on the second opening 17 side. When the cushion 9 abuts, the second opening 17 is not completely sealed, so the second opening 17 remains open.

In this example of the high-temperature gate valve, the valve body 5 is moved horizontally by the link mechanism 4 of the valve body driver 3 without tilting the drive shaft or stem, so that the packing 8 of the valve body 5 can be brought into uniform horizontal contact with the inner wall of the body 2 while maintaining the vertical position of the valve body 5, thereby sealing the first opening 16.

In this example, on the side of the first opening 16, the packing 8 of the valve body 5 forms a valve-closed seal, and on the opposite side, the cushion 9 of the tension plate 7 presses against the inner wall of the body 2 on the side of the second opening 17. When the valve body 5 is closed, the valve body 5 and the tension plate 9 abut against the inner wall surface of the body 2 on both sides of the body opening. Since the valve body driver has a double-opening structure that can be driven horizontally, the valve body driver does not become eccentric or inclined. This prevents the valve body and tension plate from colliding with the inner wall surface of the body during valve opening and closing operations, eliminating vibration and noise during valve opening and closing operations at high temperatures.
Furthermore, the high temperature gate valve of this embodiment has a structure in which the valve body 5 and the tension plate 7 are tensioned when the valve is closed, so that the valve is stably closed and the valve is easily maintained in the closed state.

In addition, since the constant load spring 36 of the constant load unit 35 is configured to be able to apply the load necessary to close the valve, the elastic force of the constant load spring 36 of the constant load unit 35 is transmitted via the link mechanism 4 in the horizontal direction in which the valve is closed and sealed, and the pressing force for closing the valve is increased by the pressing force of the link mechanism 4 and the elastic force of the constant load spring 36. As a result, there is no need to tilt the valve body or stem, and a pressing force sufficient to maintain the valve closed state can be applied, making it possible to maintain a stable valve closed state even at high temperatures.
Furthermore, the drive shaft and stem only need to have a certain degree of rigidity, and there is no need to use materials with excessive rigidity for the drive shaft and stem in order to apply a pressing force.

Furthermore, in this example, the cross-sectional shape of the packing 8 of the valve body 5 and the cross-sectional shape of the cushion 9 of the tension plate 7 are different, and when the valve is in the closed state, the deformation amount V1 of the packing 8 of the valve body 5 and the deformation amount V2 of the cushion 9 of the tension plate 7 are approximately the same.
The packing 8 of the valve body 5 has a cross-sectional shape that allows for increased surface pressure so as to fully demonstrate the valve closing performance, while the cushion 9 of the tension plate 7 has a cross-sectional shape that allows for sufficient elastic function with the minimum necessary size.

When the valve body 5 is closed (valve closed state), the amount of deformation V1 of the packing 8 and the amount of deformation V2 of the cushion 9 are the same, so the amount of horizontal movement of the valve body 5 and tension plate 7 by the link mechanism 4 are the same, and the drive shaft does not bend, so the valve body does not tilt, and the horizontal pressing force (valve closing sealing force) when performing the sealing function is stable, making it easier to maintain a stable valve closed state even at high temperatures.

Compared to a conventional structure in which the valve body is tilted and the seal member of the valve body is brought into contact with the sealing surface of the body to close the valve, in the high-temperature gate valve of this example, the valve body 5 moves horizontally to close the valve, making it easier to make the sealing surface pressure on the packing 8 of the valve body 5 uniform, so that uneven surface pressure is less likely to occur on the packing 8 of the valve body 5 when the valve is closed, improving the stability of the sealing performance when the valve is closed when used at high temperatures and providing excellent durability of the packing 8.

Furthermore, by designing the cross-sectional shape so that the deformation amount V1 of the packing 8 of the valve body 5 and the deformation amount V2 of the cushion 9 of the tension plate 7 are approximately the same when the valve is closed, when the packing 8 thermally expands, the cushion 9 on the opposite side is compressed via the link mechanism 4, making it possible to absorb the difference in elastic displacement due to thermal expansion and preventing the occurrence of overload on the packing 8.
In addition, by adjusting the contact area, the deformation amount V1 of the packing 8 and the deformation amount V2 of the cushion 9 can be easily adjusted to be approximately the same.

As shown in FIG. 6(c), when the valve body driver 3 is in the valve closed position, the center guide 22 and the link block 15 are disengaged. In the valve closed position, the drive shaft 21 can move slightly in the horizontal direction (black arrow), allowing the drive shaft 21 to bend slightly.

In addition, in this example, since the drive shaft 21 can move slightly up and down (black arrow) when the valve is closed, the drive shaft 21 can be pushed down via the link mechanism 4 when the overload on the packing 8 of the valve body 5 is absorbed by the cushion 9 on the opposite side. Therefore, for example, when the valve body 5 is heated by high temperature and thermal expansion occurs in the packing 8, the amount of deformation of the packing 8 due to thermal expansion can be transmitted to the amount of movement in the direction of the drive shaft 21 via the link mechanism 4.

That is, when the valve body 5 is heated to a high temperature and thermal expansion occurs in the packing 8, the displacement due to the thermal expansion of the packing 8 is transmitted to the link mechanism 4, and the amount of movement is absorbed by the cushion 9. Then, when the load is excessively larger than the elastic force of the cushion 9, the link mechanism 4 presses down the drive shaft 21 in the vertical direction, and the constant load spring 36 is compressed α by the load from the drive shaft 21 direction.
As a result, the overload caused by the thermal expansion of the packing 8 of the valve body 5 can be absorbed by the compression α of the constant load spring 36, thereby preventing the occurrence of an overload on the packing 8 of the valve body 5 in the valve closed state. In this example, the occurrence of an overload on the packing 8 of the valve body 5 is prevented, so that wear of the packing 8 can be reduced.

Furthermore, when the drive shaft 21 is raised to the valve-closed position, it separates from the center guide 22 and becomes free, and the drive shaft 21 flexes to compensate for the difference in elastic displacement between the packing 8 and the cushion 9, allowing the link 12 to move in the reciprocating direction of the piston 13, so that when the valve body 5 is heated to a high temperature and the packing 8 expands, the drive shaft 21 flexes and the link 12 moves toward the piston 13 (toward the cushion 9), compressing the cushion. For example, if the cushion 9 is made of PTFE, only the packing 8 is compressed when the cushion 9 touches the ground, so the link block 15 is displaced from the center of the stem by half the amount of compression movement of the packing 8, but no bending load is applied to the highly rigid stem member, and the valve body 5 can be closed evenly parallel while maintaining its vertical position.
In this way, even if thermal expansion occurs under high temperatures, the vertical attitude of the valve body 5 is maintained, so that stable valve closing performance can be maintained.

The high-temperature gate valve of this example is superior to conventional high-temperature countermeasures because it can release the deformation caused by thermal expansion even if thermal expansion occurs in the packing 8 of the valve body 5 or the cushion 9 of the tension plate 7 at high temperatures, and wear of the packing 8 and cushion 9 is suppressed, thereby increasing the durability of the packing 8 of the valve body 5 and the cushion 9 of the tension plate 7 even when used at high temperatures. In addition, because wear of the packing 8 and cushion 9 is reduced, it is possible to suppress the generation of particles from the packing 8 and cushion 9 and maintain stable valve closing performance.

In addition, in this example, a locking means 46 is provided on the air cylinder 41, so that the piston 42 that has been raised to the valve closed position can be fixed in position by the lock pin 46, thereby maintaining the valve closed state even if the external air supply means or the like is stopped.
The constant load spring 36 of the constant load unit 35 applies a pressing force in the valve closing direction, and the locking means 46 allows the valve to close more stably even at high temperatures.

In addition, the cushions 9 provided above and below the tension plate 7 are designed to be braced against the upper and lower surfaces of the inner wall of the second opening 17 of the body 2, so the tension plate 7, which has no sealing function, can be made as small as possible to avoid increasing the size of the valve body driver 3, while still achieving a compact high-temperature gate valve.

Furthermore, a recess 19 is formed in the inner wall on the second opening 17 side of the body 2, and a dividing body wall 20 is provided to reduce the thickness of the non-sealed side to the minimum, thereby making it possible to make the high-temperature gate valve compact while suppressing the thickness of the body 2 in the width direction.
In addition, the thickness of the body 2 is increased without changing the thickness of the body 2 except for the recessed portion, and the non-sealed side is made as thin as possible to achieve compactness while ensuring a predetermined strength.

The high-temperature gate valve of this example allows for a compact gate valve used at high temperatures, and therefore contributes to the compactness of the entire semiconductor device when used as a gate valve to separate the chamber and the transfer chamber.

Next, the operation when opening the valve will be described. To open the high temperature gate valve of this example, air is supplied from the air supply and exhaust passage 45 to the cylinder chamber 44 of the air cylinder by an external air supply means (not shown), causing the piston 42 of the air cylinder 41 to descend. The output shaft 43 of the air cylinder 41 descends, causing the drive shaft 21 connected to the drive shaft plate 33 to also descend.

In this example, the elastic force of the compressed valve-opening spring 34 is applied in the direction in which the drive shaft 21 descends, so the speed at which the drive shaft 21 descends can be increased.

When the drive shaft 21 descends to a predetermined valve open position, the vertical displacement of the link block 15 of the link mechanism 4 in the valve element drive element 3 is converted to a horizontal direction via the link 12, causing the piston 13 to move horizontally, causing the valve element mounting plate 6 connected to the piston 13 to move horizontally in a direction away from the first opening 16 in the inner wall of the body 2, and the valve element 5 attached to the valve element mounting plate 6 to move horizontally in a direction away from the first opening 16. When the valve element 5 releases the valve-closed seal of the first opening 16, the high-temperature gate valve enters an open valve state.
At the same time, the vertical displacement of the link block 15 of the link mechanism 4 is converted horizontally via the link 12 on the second opening 17 side, causing the piston 13 on the second opening 17 side of the link mechanism 4 to move horizontally, and the tension plate 7 connected to the piston 13 moves horizontally in the direction away from the second opening 17, causing the cushion 9 to move away from the inner wall of the body 2.

In this example of a high-temperature gate valve, the valve body 5 and tension plate 7 move horizontally at the same time due to the link mechanism 4 of the valve body driver 3, and the amount of horizontal movement is the same, so there is no wobble or bias when the valve is opened, and vibration and noise can be suppressed when the valve is opened.

As shown in FIG. 6B , when the drive shaft 21 descends to a predetermined position, the locking portion 23 of the center guide 22 locks onto the link block 15 .
When the valve body driver 3 is in the valve open position, the movement of the drive shaft 21 is restricted by the engagement between the locking portion 23 of the center guide 22 and the link block 15, fixing the position of the drive shaft 21 and preventing the drive shaft 21 from bending or rattling, thereby suppressing the generation of vibrations and noise during the valve opening operation.

In the valve open position, the drive shaft 21 is fixed in position, so when the high-temperature gate valve is in the open state, the drive shaft 21 does not move, preventing bending or rattling of the drive shaft 21, and the high-temperature gate valve of this example can maintain a stable valve open state.

In this way, in the high-temperature gate valve of this example, when the valve is opened or closed, the link mechanism 4 of the valve body driver 3 moves the valve body 5 and the tension plate 7 horizontally at the same time, ensuring that the horizontal movements are the same amount, thereby ensuring stable valve opening and closing operation even at high temperatures.
Furthermore, by forming the packing 8 and cushion 7 into a shape that causes them to deform by approximately the same amount due to the tightening load of the valve body 5 applied by the valve body driver 3, the pressing force on both sides is approximately the same when the valve is closed and sealed, and unevenness or bias in the surface pressure is less likely to occur on the contact surfaces of the packing 8 and cushion 7, which are made of resin materials, and vibrations and noise are less likely to occur when the valve is opened and closed.
Furthermore, the occurrence of overload on the packing 8 (sealing member) and cushion 9 of the valve body, which are susceptible to wear at high temperatures, can be eliminated, improving the durability of the high-temperature gate valve.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention described in the claims of the present invention.

In the above embodiment, the actuator 40 that moves the drive shaft 21 up and down is configured as a pneumatic actuator, but it may also be configured as an electric actuator. Also, the locking means may be configured as a cam mechanism, a cam groove, etc.

REFERENCE SIGNS LIST 2 Body 3 Valve body driver 4 Link mechanism 5 Valve body 6 Valve body mounting plate 7 Tension plate 8 Packing 9 Cushion 15 Link block 16 First opening 17 Second opening 19 Recess 21 Drive shaft 32 Guide plate
33 Drive shaft plate 35 Constant load unit 36 Constant load spring 40 Actuator 43 Output shaft

Claims (6)

A high-temperature gate valve comprising: a drive shaft that moves up and down within the body; a valve body driver that is attached to the drive shaft and moves horizontally relative to the drive shaft; a horizontally long valve body having a packing made of an elastic material that seals the inner wall surface of the opening of the body on one side of the valve body driver; and a horizontally long tension plate having a cushion made of an elastic material that presses against the wall surface of the body on the other side of the valve body driver, the packing and the cushion being formed in a shape that causes approximately equal deformation amounts due to the tightening load of the valve body by the valve body driver. The high-temperature gate valve according to claim 1, in which the packing and the cushion are formed with contact areas such that the amount of deformation when the valve is closed at high temperatures is approximately the same. The high-temperature gate valve according to claim 1 or 2, in which the body has a first opening and a second opening that are elongated in the thickness direction, and recesses are formed on the inner wall of the body in the horizontal movement area and the vertical movement area of the tension plate within the body, so that the thickness width of the body other than the recesses is not changed. The high-temperature gate valve according to claim 3, wherein the cushions provided above and below the tension plate surface are structured to brace against the upper and lower surfaces of the inner wall of the second opening of the body. The high-temperature gate valve according to any one of claims 1 to 4, wherein the valve body driver is structured to include a link block attached to the drive shaft, a link mechanism attached to the link block, and a piston provided in the link mechanism that operates when the drive shaft moves up and down. A high-temperature gate valve according to any one of claims 1 to 5, in which an output shaft that moves up and down by an actuator is attached to a drive shaft plate provided at the lower end of the multiple drive shafts, a constant load unit having a constant load spring is provided on this output shaft, and at high temperatures, the packing and the cushion expand to press down the drive shaft, compressing the constant load spring and preventing the application of an excessive load.

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