JP4237032B2 - On-off valve and exhaust system for semiconductor manufacturing equipment using the same - Google Patents

Description

  The present invention relates to an on-off valve that handles a viscous fluid or a granular material and an exhaust device using the same, and more particularly to an on-off valve that is suitable for semiconductor manufacturing equipment and the like and an exhaust device for semiconductor manufacturing equipment using the same.

In a semiconductor manufacturing apparatus, particularly a manufacturing apparatus using a plasma CVD method, a raw material gas such as silane gas SiH ₄ and oxygen gas O ₂ are reacted to deposit a thin film such as silicon dioxide on a substrate. However, granular silicon dioxide that does not accumulate on the substrate floats inside semiconductor manufacturing equipment and exhaust equipment as a by-product, adversely affects the substrate, or adheres to valves in the exhaust equipment and operates. It may cause defects. Therefore, the following techniques are known as techniques for removing the influence of these by-products (see, for example, Patent Document 1).

  For example, the semiconductor manufacturing apparatus described in Japanese Patent Application Laid-Open No. 9-279351 (Patent Document 1) is inert to the exhaust pipe from the deposition film formation chamber to the exhaust pump after the deposition film formation is completed or during the deposition film formation process. Gas is introduced and the exhaust pipe formed during deposition film formation and the powder, which is a CVD byproduct attached to the conductance adjusting valve, is sucked and removed by a dust collector provided on the pipe branched from the exhaust pipe. . After purging the chamber and exhaust pipe with inert gas, open and close the valves before and after the conductance adjustment valve to shut off the chamber and exhaust pipe, and then remove the CVD by-product adhering to the exhaust pipe. It is blown away by and collected with a dust collector. The collected powder is wet-treated with a water shower to prevent ignition and is safely discharged out of the manufacturing apparatus.

As described above, the valve that opens and closes the flow path of the exhaust pipe needs to be surely opened and closed even if the fluid is a granular material, and is particularly required to have a high valve seat sealability.
On the other hand, as a general valve for handling powder particles, a knife gate valve and a slide gate valve are known in which a plate-like valve body is inserted at right angles to the flow path in the valve body and the valve is closed while cutting the fluid. (For example, refer to Patent Document 2 or 3).

  For example, a knife gate valve described in Japanese Patent Application Laid-Open No. 59-144877 (Patent Document 2) includes a plate-shaped valve body having a sharp tip at a tip and a columnar stem that moves up and down the gland packing. A structure that prevents fluid from leaking from the valve to the outside by providing a hermetically sealed support is provided, and a cleaning ring is provided on the inner peripheral surface of the inlet-side flow path hole of the valve. By spraying water and air during opening and closing, the granular material adhering to the plate-shaped valve body and the annular valve seat having an H-shaped cross section in contact with the outlet side surface of this plate-shaped valve body is washed away, thereby smoothly opening and closing the valve body. It is to make.

In addition, the slide gate valve described in Japanese Patent Application Laid-Open No. Sho 62-188863 (Patent Document 3) has a structure in which the resin fluid adhering to the valve body is scraped off by a scraper portion provided at the valve hole edge of the valve body. Like the knife gate valve described in JP-A-59-144877 (Patent Document 2), the valve body can be automatically cleaned when the valve is opened and closed without interrupting the use of the valve. It is.
JP-A-9-279351 JP 59-144877 A Japanese Patent Laid-Open No. 62-188863

However, Japanese Patent Application Laid-Open No. 59-144877 (Patent Document 2) requires a new injection mechanism for water or the like, which increases the cost, and in addition to the outlet side surface of the valve body, that is, the valve seat. Since the sliding surface cannot be cleaned, the powder particles adhering to the valve body could not be completely removed. Further, the cleaning operation must be performed in a state where the use of the valve is interrupted and the fluid in the valve is removed, and the valve cannot be used continuously. Moreover, since the shape of the annular valve seat is H-shaped in cross section, the sliding surface with the valve body becomes a recess, and the powder seats may accumulate in this recess, which may reduce the valve seat sealability. When the sliding surface pressure between the valve body and the valve seat is increased to eliminate this, the opening / closing operation force of the valve body increases, and the acute angle tip of the plate-shaped valve body damages the valve seat, On the contrary, the valve seat sealability may be deteriorated.
Furthermore, since the plate-like valve body is hermetically supported by the multilayer packing, the opening / closing operation force of the valve body increases, and the sealing performance is concentrated on the upper packing that is directly pressed by the packing pressing member. As a result, the sealing performance becomes insufficient, and there is a possibility that the granular material leaks.

  Japanese Patent Application Laid-Open No. 62-188863 (Patent Document 3) discloses that a part for removing deposits on the valve body must be separately attached, and that the part protrudes from the edge of the valve hole into the flow path. As a result, the fluid is likely to accumulate inside the valve.

  The present invention was developed as a result of diligent research in order to solve the above problems, and its object is to remove the fluid adhering to the valve body and the valve seat without increasing the number of parts. Prevents valve seat leakage and external leakage, realizes a structure that prevents fluid from accumulating inside, and suppresses the opening and closing operation force of the valve, ensuring extremely high valve seat sealing performance for a long period of time An object of the present invention is to provide an excellent on-off valve and an exhaust device for semiconductor manufacturing equipment using the same.

To achieve the above object, the invention according to claim 1, the annular valve seat is attached to the flow path opening of the body, the hanging Do not plate-shaped valve body stem lifting and lowering freely by sliding contact with the annular valve seat The plate-like valve body is provided so as to be accommodated in a valve-body accommodating portion having a rectangular cross section formed on the body, and the granular material adhering to the plate-like valve body is scraped off at the upper end portion of the valve body accommodating portion. A wiper packing is mounted, and the outer periphery of the plate-shaped valve body is guided in close contact with the wiper packing, and an upper-end pressing taper surface provided at the upper end of the plate-shaped valve body by a stem taper surface provided at the lower portion of the stem. When the flow path port is sealed with a plate-shaped valve element by pressing in the stem axis direction, the plate-shaped valve element is pressed in the cross direction of the stem axis and the plate-shaped valve element is pressed against the annular valve seat. This is an on-off valve that seals the channel opening.

Invention, the pre-Symbol insertion hole formed in the upper end of the plate-like valve member, provided to be movable in the valve body engaging portion formed toward the stem axis and intersecting direction to the lower end of the stem the stem according to claim 2 It is an on-off valve in which a plate-like valve body is suspended at the lower end.

  The invention according to claim 3 is an on-off valve in which a thin stepped surface is formed on the upper side surface of the plate-like valve body on the annular valve seat side.

  The invention according to claim 4 is an on-off valve in which the plate-like valve body is arranged at a position separated from the annular valve seat when the plate-like valve body is fully opened.

According to claim 5 invention, prior Symbol a lower end pressing the tapered surface of the plate-like valve member is pressed against the Bodetepa surface provided in the flow path bottom of the body, press seal the plate-like valve body annular valve seat to fully closed Open / close valve.

  The invention according to claim 6 is an on-off valve in which a bonnet is provided on the upper portion of the body, and a stem is slidably sealed with a shaft seal packing attached to the bonnet.

The invention according to claim 7, a semiconductor fabrication facility exhaust system arranged the opening and closing valve at an appropriate position of the exhaust system for semiconductor manufacturing equipment.

According to the first aspect of the present invention, when the plate-shaped valve body is fully closed, the plate-shaped valve body is strongly pressed against the annular valve seat, so that the valve seat sealability can be ensured regardless of the fluid flow direction. It becomes possible.
Furthermore, the annular valve seat acts as a wiper, scraping off foreign matters such as powder particles adhering to the plate-like valve body, preventing foreign matter from intervening between the plate-like valve body and the annular valve seat, It is possible to ensure the valve seat sealing performance.

  According to the second aspect of the present invention, the plate-like valve body is engaged with the valve-body engaging portion formed at the lower end of the stem while being engaged with the plate-like valve body. It is possible to press strongly in the direction of the flow path.

  According to the invention of claim 3, when the step portion of the plate-like valve body passes through the wiper portion, the thin step portion surface of the plate-like valve body comes into sliding contact with the wiper packing, and the wiper on the annular valve seat side The pressing force of the packing to the plate-like valve body can function as a valve body guide function by the wiper packing and a second wiper portion for the plate-like valve body.

  According to the fourth aspect of the present invention, in the fully opened state of the valve, while preventing the powder particles from staying inside the body holding the valve body, the particles adhered to the tip of the valve body when the valve is closed. It can be removed by the valve seat.

  According to the fifth aspect of the present invention, the pressing force of the plate-shaped valve body required for the valve seat seal against the annular valve seat is generated only when the plate-shaped valve body is fully closed. The contact pressure between the ring-shaped valve body and the annular valve seat can be set to the minimum pressing force necessary to remove foreign matter adhering to the plate-shaped valve body, and while preventing the annular valve seat from being worn, the valve seat seal It becomes possible to ensure the sex.

  According to the invention of claim 6, since the gas fluid is sealed by the shaft seal packing of the bonnet, the sliding resistance between the plate valve body and the wiper packing can be suppressed, and the operation torque of the plate valve body is reduced. However, it is possible to prevent external leakage of the gas fluid.

In addition , the annular valve seat acts as a wiper to scrape off foreign matters such as powder particles adhering to the plate-like valve body, and prevent foreign matter from intervening between the plate-like valve body and the annular valve seat, It is possible to ensure the valve seat sealing performance. Furthermore, since the inclined surface such as a rounded surface or a tapered surface is formed at the lower end edge of the plate-like valve body on the annular valve seat side, the valve seat sealing performance is maintained for a long time without damaging the annular valve seat. It becomes possible.

According to the seventh aspect of the present invention, the on-off valve of the present invention can reliably close the valve, so that by-products generated in the semiconductor manufacturing facility can be discharged to the outside without backflowing. An exhaust device for a semiconductor manufacturing facility can be provided.

An embodiment of an on-off valve according to the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of an on-off valve 1 according to the present invention. As shown in the figure, a body 2 has a plate-like valve body 3 that can be moved up and down, and this plate-like valve body. 3 is attached to and detached from the annular valve seat 5 attached to the cylindrical flow path port 4, and the flow path port 4 is shut off or communicated to open and close pipe lines (not shown) connected to both sides of the body 2. . In the figure, reference numeral 6 denotes an annular seat retainer having an L-shaped cross section for supporting the inner peripheral surface of the annular valve seat 5 and the non-seal side surface, and 7 in the figure designates the annular seat retainer 6 as a body 2. An annular insert that is pressed and held inside. Reference numeral 8 denotes a lifting stem. A lower end of the stem 8 is provided with a valve body locking portion 8a formed in a direction crossing the stem axis, and the upper end of the plate-like valve body 3 is provided. By inserting the insertion hole 3a formed in the valve body movably into the valve body locking portion 8a, the plate-like valve body 3 is parallel to the annular valve seat 5 and can be moved horizontally in the stem 8. It has a suspended structure.

  As shown in FIG. 1, the plate-like valve body 3 is formed with an upper end pressing taper surface 3b at the upper end of the annular valve seat 5 on the non-valve seat side and a lower end pressing taper surface 3c at the lower end. When the plate-like valve body 3 to be described later is fully closed, the upper end pressing taper surface 3b is pressed by the stem taper surface 8b provided at the lower portion of the stem 8, and the lower end pressing taper surface 3c is applied to the bottom of the flow path port 4 of the body 2. The plate-shaped valve body 3 is pressed by the provided body taper surface 4a to seal the plate-like valve body 3 against the annular valve seat 5 when fully closed. 4a and the stem taper surface 8b constitute a pressing mechanism that presses the plate-like valve body 3 against the annular valve seat 5 when fully closed. As shown in the figure, the pressing mechanism is located on the extension line of the stem axis. Reference numeral 4b in the figure denotes a valve body tip housing portion that houses the tip of the plate-like valve body 3 when fully closed. In this example, the stem taper surface 8b and the body taper surface 4a have an angle inclined about 30 degrees with respect to the stem axis, and this inclination angle is the upper end pressing taper surface 3b of the plate-like valve body 3, The lower end pressing taper surface 3c is substantially the same. In addition, the body taper surface 4a is formed in the outer diameter direction from the flow path port 4 so as to eliminate the protrusion to the flow path port 4 so that the granular material is not easily collected.

  As shown in FIG. 2, the annular valve seat 5 of this example made of resin such as PTFE has inclined surfaces 5 a and 5 b on the seal side with the plate-like valve body 3, and seals with the plate-like valve body 3. The surface 5c has a narrow band-like cross-sectional shape and has a shape in which the pressure on the sealing surface with the plate-like valve body 3 is increased and the granular material is less likely to adhere to the sealing surface 5c. Further, the seal surface 5 c has a shape protruding toward the plate-like valve body 3 so as to always come into contact with the plate-like valve body 3 even when the plate-like valve body 3 is opened and closed. For example, in the nominal diameter 50A of the valve, the inner diameter φ53 mm of the annular seat retainer 6 × the outer diameter φ75 mm, the width of the seal surface 5 c is about 2 mm, the angle of the inner inclined surface 5 a is about 45 degrees, and the angle of the outer inclined surface 5 b is about 16 I am trying.

  A protrusion 5d is formed on the outer periphery of the annular valve seat 5, and the protrusion 5d is engaged with a step 2a formed on the inner surface of the body 2 so that the annular insert 7 is inserted into the body 2. Thus, the annular valve seat 5 and the annular seat retainer 6 are pressed and held in the body 2. Since the inner peripheral surface of the annular valve seat 5 is supported by the annular seat retainer 6, even if it is in close contact with the plate-like valve body 3, it is not deformed to the inner diameter side, and the valve seat sealability can be ensured. Since the non-seal side surface of the annular valve seat 5 is also protected by the annular seat retainer 6, the annular valve seat 5 is prevented from being damaged when the annular insert 7 is inserted into the body 2. Further, an O-ring 9 is disposed on the outer periphery of the annular seat retainer 6 to prevent fluid from leaking to the outside from between the body 2 and the annular insert 7.

  As shown in FIG. 3, the plate-like valve body 3 in this example is a plate-like valve body having a rectangular shape on the upper side and a semi-disc shape on the lower side, and as described above, the upper rectangular portion includes the stem 8. An insertion hole 3a that engages with the valve body locking portion 8a is formed through the plate thickness, and the plate-like valve body 3 that engages with the stem 8 is parallel to the annular valve seat 5 in the horizontal direction. Arranged in a movable state. A tapered surface (inclined surface) 3d that slides with the annular valve seat 5 is formed at the lower edge of the annular valve seat 5 side. The angle of inclination of the tapered surface 3d is equal to or greater than the angle of the outer inclined surface 5b of the annular valve seat 5, and when the plate-like valve body 3 is fully opened, the powder that has entered the valve body accommodating portion 10 above the body 2 described later Granules are easily discharged to the flow path port 4 from between the tapered surface 3d and the outer inclined surface 5b of the annular valve seat 5. In this example, the tapered surface 3d is formed, but it may be a rounded surface (inclined surface) (not shown), and in this case, the rounded dimension is set so as to obtain the same effect as the tapered surface 3d. . In this way, by forming a tapered surface or a rounded surface at the lower end edge of the plate-like valve body 3 on the annular valve seat 5 side, the plate-like valve body 3 makes the seal surface 5c of the annular valve seat 5 in the valve closing operation. It rides smoothly on the annular valve seat 5 without damaging it.

  The pressing state of the lower end pressing taper surface 3c and the body taper surface 4a when the plate valve body 3 is fully closed will be described. The lower end pressing taper surface 3c is formed as shown in FIG. It is formed in a semicircular shape along the edge portion, and in this case, as shown in FIG. 4B, the lowermost end portion of the lower end pressing taper surface 3c is partially in contact with the body taper surface 4a. The sliding resistance between the plate valve body 3 and the body taper surface 4a is kept low. In FIG. 4A, A in the drawing indicates a region where the lowermost end portion of the lower end pressing taper surface 3c contacts the body taper surface 4a.

  On the other hand, as shown in FIG. 5A, the lower end pressing taper surface 3c may be provided as a flat portion in the vicinity of the lowermost end portion of the plate-like valve body 3. In this case, as shown in FIG. The substantially whole surface of the lower end pressing taper surface 3c comes into contact with the body taper surface 4a, and the parallelism between the plate-like valve body 3 and the annular valve seat 5 can be kept uniform. Further, as shown in FIG. 5A, an inclined portion 3e is provided on the side opposite to the annular valve seat 5 side of the plate-like valve body 3, and the flow path port 4 is formed by the inclined portion 3e. Even when the viscosity of the flowing fluid is high, the valve can be closed by scraping the fluid. In FIG. 5A, A in the drawing indicates a region where the lowermost end portion of the lower end pressing taper surface 3c contacts the body taper surface 4a.

  As shown in FIG. 1 and FIG. 2, the valve body housing portion 10 is a housing portion having a rectangular cross-section located in the crossing direction with the flow path port 4, and the upper end portion of the valve body housing portion 10 is made of a braid ( For example, a wiper packing 13 which is non-asbestos + PTFE impregnated) and a metal spacer 12 are alternately provided in the vertical direction (sliding direction of the valve body), and a wiper portion 13 is provided. The wiper packing 11 provided in close contact with the body 3 allows the plate-like valve body 3 housed in the valve body housing portion 10 to slide in a freely guideable manner and adheres to the plate-like valve body 3. Scrapes. As shown in the figure, by disposing the spacer 12 on the uppermost part of the wiper portion 13, the wiper packing 11 is prevented from jumping out above the body 2, and thus, when the on-off valve 1 is assembled. The wiper packing 11 can be easily attached to the body 2. Further, the wiper packing 11 allows only a gas body to permeate without allowing the solid or liquid such as a granular material to permeate through the packing.

  Further, as shown in FIG. 1, the plate-like valve body 3 has a thin plate thickness in a region in contact with the wiper portion 13 when the plate-like valve body 3 is fully closed, and this thin stepped surface 3f. The thickness a of the valve is, for example, about 6.5 mm, which is 0.5 mm thinner than the thickness b (about 7 mm) of the thick part 3 g at the nominal diameter 50A of the bulb. The step portion 3h that becomes the boundary between the step portion surface 3f and the thick portion 3g is tapered or rounded so that the annular valve seat 5 is not damaged when the plate-like valve body 3 is moved up and down.

  In the figure, reference numeral 14 denotes a box-shaped bonnet. A flange portion 14 a formed on the bonnet 14 and a flange portion 2 b formed on the upper portion of the body 2 are connected via a bolt 15, and an O-ring 16 is connected. It is installed in a sealed state. By connecting the bonnet 14, the wiper part 13 is pressed so that the wiper packing 11 is pressed against the plate-like valve body 3 with an appropriate surface pressure. A shaft seal packing 17 for shaft sealing the stem 8 inserted in the bonnet 14 is disposed on the upper portion of the bonnet 14. The shaft seal packing 17 is interposed via a gland 18 disposed on the upper portion. It is pressed by the ground presser 19 to give a surface pressure necessary for shaft sealing of the stem 8. As shown in FIG. 3, the gland retainer 19 is provided by screwing a nut 21 to a bolt 20 fixed to the upper portion of the bonnet 14. In the figure, reference numeral 22 denotes a yoke on which an operation unit such as an actuator (not shown) is placed, and is fixed to the bonnet 14 via a bolt 23. In the figure, reference numeral 24 denotes a back sheet portion for contacting a later-described step portion 8 c formed on the outer periphery of the stem 8.

  As shown in FIG. 1, the bonnet 14 is provided with two purge holes 25 communicating with the outside. When the gas body staying inside the bonnet 14 needs to be purged at the time of maintenance, the purge holes 25 are provided. A purge air supply pipe (not shown) is connected to 25, and the purge hole 25 is closed with a plug 26 when purging is unnecessary or before piping.

Next, the operation of the above embodiment will be described.
FIG. 6 is an explanatory view showing a state in which the plate-like valve body 3 is fully opened. As shown in FIG. 6, the step portion 8 c formed on the outer periphery of the stem 8 abuts on the back seat portion 24 of the bonnet 14. In the state in which the back sheet functions, the plate-like valve body 3 is in a fully open state where it does not protrude into the flow path port 4. The plate-like valve body 3 is held inside the valve in a state where a gap is formed between the tip of the plate-like valve body 3 and the annular valve seat 5. The granular material in the flow passage port 4 also enters the valve body accommodating portion 10 above the body 2, but this granular material is seen from the lower side of the plate-shaped valve body 3 as indicated by the arrow shown in FIG. 3. Since it is discharged to the flow path port 4 and also from the direction directly below the valve body, it is discharged to the flow path port 4. Therefore, according to the on-off valve 1 in this example, the granular material is accumulated in the valve body housing portion 10 above the body 2. Constructs a difficult on-off valve.

FIG. 7 is an explanatory view showing a state at the start of the valve closing operation. As shown in FIG. 7, the stem 8 is lowered by operating a handle or an actuator (not shown). Eventually, the lower end of the plate-like valve body 3 comes into contact with the annular valve seat 5. Since the tapered surface 3d (or rounded surface) is formed at the lower end edge of the plate-like valve body 3 on the annular valve seat 5 side, the plate-like valve body 3 does not damage the seal surface 5c of the annular valve seat 5. Smoothly ride on the seal surface 5c. The flow path blocking surface 3 i of the plate-like valve body 3 is in sliding contact with the boundary edge between the outer inclined surface 5 b of the annular valve seat 5 and the seal surface 5 c, and the annular valve seat 5 is a first wiper for the plate-like valve body 3. It functions as a part, and the granular material adhering to the plate-like valve body 3 is scraped off by the annular valve seat 5. At the same time, the boundary edge between the tapered surface 3d (inclined surface) formed on the lower end edge of the plate-like valve body 3 on the annular valve seat 5 side and the flow passage blocking surface 3i forms the seal surface 5c of the annular valve seat 5. It slides into contact and functions as a wiper for the annular valve seat 5 to scrape off the powder particles adhering to the seal surface 5c. Since the sealing surface 5c has a narrow belt-like cross section and a substantially mountain-shaped cross section, it is difficult for the powder particles to adhere, but the powder particles adhered to the sealing surface 5c are still scraped off by the plate-like valve body 3. I am doing so.
Therefore, according to the on-off valve 1 in this example, the granular material adhering to the sealing surface 5c of the plate-like valve body 3 or the annular valve seat 5 is removed without using another component that protrudes to the flow path port 4. It is possible to improve the valve seat sealability.

  FIG. 8 is an explanatory view showing a state during the valve closing operation. As shown in FIG. 8, the plate-like valve body 3 is in sliding contact with the annular valve seat 5, and the wiper portion 13 provided on the body 2 Descent in a guided state. The pressing force of the wiper portion 13 on the plate-like valve body 3 is equal on the annular valve seat 5 side and on the opposite side to the annular valve seat 5 side.

  FIG. 9 is an explanatory view showing a state before the plate-like valve body 3 is fully closed. As shown in FIG. 9, when the stepped portion 3h of the plate-like valve body 3 passes through the wiper portion 13, the plate-like valve is shown. The thin stepped surface 3 f of the body 3 comes into sliding contact with the wiper packing 11, and the pressing force of the wiper packing 11 on the annular valve seat 5 side to the plate-like valve body 3 is a valve body guide function by the wiper packing 11. And while maintaining the function as the 2nd wiper part with respect to the plate-shaped valve body 3, it becomes what fell a little.

FIG. 10 is an explanatory view showing a state in which the plate-like valve body 3 is fully closed. As shown in the figure, the plate-like valve body 3 is connected to the stem 8 and the body 2 on the extension line of the stem 8. Sandwiched between. As the stem 8 descends, as shown by the arrow in the figure, the stem 8 presses the plate-like valve body 3 downward, and as a reaction force the body 2 pushes back the plate-like valve body 3 upward. The force is converted into a force in the valve seat direction (horizontal direction) via each tapered surface. The plate-like valve body 3 is strongly pressed perpendicularly (flow direction) to the annular valve seat 5 while being guided by the valve body locking portion 8a formed at the lower end of the stem 8. Since the pressing mechanism composed of each tapered surface is located on the axis of the stem 8, the plate-like valve body 3 can be more reliably pressed against the annular valve seat 5.
Therefore, when the plate-like valve body 3 is fully closed, the plate-like valve body 3 is strongly pressed against the annular valve seat 5, so that regardless of the fluid flow direction or the piping direction (horizontal or vertical) of the on-off valve 1, Valve seat sealability can be ensured.

  Further, since the pressing force between the plate-like valve body 3 and the annular valve seat 5 necessary for the valve seat seal is generated only when the plate-like valve body 3 is fully closed, the plate-like valve body in the valve opening / closing process. 3 and the annular valve seat 5 can be suppressed to the minimum necessary surface pressure that can remove the powder particles adhering to the plate-like valve body 3 and the annular valve seat 5 by sliding contact of both parts. In addition, the operating torque of the valve can be kept low, the wear of the annular valve seat 5 is small, and the valve seat sealability can be ensured over a long period of time. In addition, since the seal-side cross section of the annular valve seat 5 has a substantially trapezoidal shape, if the pressing force of the plate-like valve body 3 on the annular valve seat 5 increases when fully closed, the plate-like valve body 3 and the annular valve seat 5 The contact area is increased, and even if the annular valve seat 5 is worn slightly, the influence thereof is small, and the valve seat sealability can be ensured over a long period of time.

  When the plate-shaped valve body 3 is strongly pressed toward the annular valve seat 5 side, the amount of pressing of the wiper packing 11 on the annular valve seat 5 side is determined when the wiper packing 11 presses the thick portion 3g of the plate-shaped valve body 3. Therefore, an excessive pressing force is not applied to the wiper packing 11, and the wiper function can be maintained over a long period of time. Furthermore, the plate-like valve body 3 engaged with the stem 8 can be pressed against the annular valve seat 5 only by the lowering operation of the stem 8 without using a complicated cam structure, etc. It is possible to obtain a valve with a high valve seat sealability with few failures.

  Further, as the stem 8 rises, the pressing amount of the plate-like valve body 3 against the annular valve seat 5 decreases, and the plate-like valve body 3 starts to rise while being in sliding contact with the annular valve seat 5. The granular material adhering to the flow path blocking surface 3i of the plate-like valve body 3 is scraped by the inner diameter of the annular valve seat 5, more specifically, the boundary edge between the inner inclined surface 5a and the seal surface 5c. Therefore, according to the on-off valve 1, the annular valve seat 5 functions as the first wiper portion for the plate-like valve body 3 even during valve operation, and the valve seat sealing performance can be improved.

  After the step 3 h of the plate-like valve body 3 passes through the wiper portion 13 provided on the body 2, the thick portion 3 g of the plate-like valve body 3 contacts the wiper portion 13. The wiper part 13 scrapes off the powder adhering to the plate-like valve body 3 over its entire circumference. The wiper portion 13 has a plurality of wiper packings 11 arranged at intervals, so that each wiper packing 11 functions as a scraper, so that the powder particles adhering to the plate-like valve body 3 are removed in a wavy manner. Thus, the granular material adhering to the plate-like valve body 3 can be efficiently removed by the wiper portion 13 having a limited height, and the valve seat sealability when the valve is closed can be improved. Moreover, since the metal spacers 12 are interposed between the plurality of wiper packings 11, the pressing force of the bonnet 14 can be reliably transmitted to the lower wiper packings 11, and the wiper effect of each wiper packing 11 is sufficiently obtained. Can be demonstrated.

Furthermore, since the number of components of the wiper packing 11 can be reduced while improving the wiper function, the contact area between the wiper packing 11 and the plate-like valve body 3 is reduced, and the operating torque of the valve is reduced. Therefore, the granular material in the body 2 does not flow out to the bonnet 14 side. Further, since the gas body in the body 2 can pass through the wiper portion 13, the opening and closing operation of the plate-like valve body 3 can be smoothly performed without the gas body being enclosed in the bonnet 14. The gas body in the bonnet 14 is prevented from leaking to the outside of the valve by the shaft seal packing 17 at the top of the bonnet 14.
Therefore, according to the on-off valve 1, the fluid inside the body 2 can be reliably prevented from leaking to the outside by the wiper portion 13 of the body 2 and the shaft seal packing 17 of the bonnet 14.

  In order to confirm the valve seat sealability of the on-off valve in the present invention, an on-off valve having a nominal diameter of 50A is horizontally piped, and durability is obtained using nitrogen gas (pressure: 1 MPa) mixed with granular silicon dioxide as a fluid. As a result of the test, it was proved that leakage of nitrogen gas from the valve seat was not confirmed even after opening and closing 20,000 times regardless of the flow direction of the fluid, and the valve seat sealability could be ensured for a long time.

Next, an exhaust device for semiconductor manufacturing equipment using the on-off valve of the present invention will be described.
As shown in FIG. 11, at least a mounting table 31 on which a substrate 30 is placed and an electrode 32 for forming a thin film on the substrate 30 are built in, and a gas cylinder 33 filled with a gas for forming a thin film can be connected. A semiconductor manufacturing apparatus (CVD apparatus) 34 is used, and in order to remove powder particles which are by-products generated when a thin film is formed on the substrate 30 by the CVD apparatus 34, the exhaust pipe 35 and the dust collector 36 are used. An exhaust device 37 is connected. The on-off valve 1 of the present invention is connected to the exhaust pipe 35 of the exhaust device 37. In this example, the on-off valve 1 is installed at two locations, and the exhaust valve 35 is disposed between the on-off valves 1 and 1. A gas cylinder 38 filled with a purge gas for removing powder particles in the pipe 35 during maintenance can be connected.
Since the exhaust device 37 for semiconductor manufacturing equipment using the on-off valve 1 of the present invention can ensure the valve seat sealing performance of the on-off valve 1 over a long period of time, the granular material is converted into a CVD device 34 during maintenance. It is possible to work safely without backflow.

  According to the exhaust device for semiconductor manufacturing equipment using the on-off valve of the present invention, the valve seat sealability of the on-off valve can be ensured over a long period of time. It is possible to work safely without backflowing. In addition to semiconductor manufacturing equipment, it can be used for liquid crystal manufacturing equipment, or for general applications in which powders, slurries and gas bodies are mixed.

It is front sectional drawing which showed the fully closed state of the on-off valve in this invention. It is the elements on larger scale which showed the open state of the on-off valve in this invention. It is side surface sectional drawing which showed the open state of the on-off valve in this invention. (A) It is operation | movement explanatory drawing of a plate-shaped valve body and a body taper surface. (B) It is a BB sectional view. (A) It is operation | movement explanatory drawing of the plate-shaped valve body and body taper surface which showed the other example. (B) It is CC sectional view taken on the line. It is a state explanatory view at the time of valve full open. It is state explanatory drawing at the time of valve closing operation start. It is state explanatory drawing during valve closing operation. It is state explanatory drawing before a valve is fully closed. It is state explanatory drawing at the time of a valve fully closed. It is the schematic explanatory drawing which showed the exhaust apparatus for semiconductor manufacturing apparatuses using the on-off valve of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 On-off valve 2 Body 3 Plate-shaped valve body 3a Insertion hole 3b Upper end press taper surface 3c Lower end press taper surface 3d Inclined surface (taper surface, round surface)
3f Step surface 4 Channel port 4a Body taper surface 5 Annular valve seat 6 Annular seat retainer 7 Annular insert 8 Stem 8a Valve body latching part 8b Stem taper surface 11 Wiper packing 14 Bonnet 17 Shaft seal packing 37 Exhaust device for semiconductor manufacturing equipment

Claims (7)

The annular valve seat is attached to the flow path opening of the body, this annular valve seat a hanging Do not plate-shaped valve body stem lifting and lowering freely by sliding, rectangular cross section formed with the plate-like valve element to the body A wiper packing is provided at the upper end portion of the valve body housing portion so as to be able to be accommodated in the valve body housing portion. The wiper packing is used to scrape powder particles adhering to the plate valve body. The outer periphery of the plate is guided in close contact with the stem and the upper end pressing taper surface provided at the upper end of the plate-like valve body is pressed in the stem axial direction by the stem taper surface provided at the lower portion of the stem. When the flow path port is sealed, the plate valve body is pressed in the cross direction of the stem axis, and the plate valve body is pressed against the annular valve seat to seal the flow path port. Opening and closing valve. The pre-Symbol insertion hole formed in the upper end of the plate-like valve member, the lower end of the stem is provided so as to be movable in the valve body engaging portion formed toward the stem axis and intersecting direction to the lower end of the stem of the plate-like valve body The on-off valve according to claim 1, which is suspended.   The on-off valve according to claim 1 or 2, wherein a thin stepped surface is formed on an upper side surface of the plate-shaped valve body on the annular valve seat side.   The on-off valve according to any one of claims 1 to 3, wherein the plate-like valve body is arranged at a position separated from the annular valve seat when the plate-like valve body is fully opened. Is pressed against the Bodetepa surface the lower pressing tapered surface provided in the flow channel bottom of the body of the previous SL plate-like valve body, any of claims 1 to 4 the plate-like valve body has sealed pressed sealed annular valve seat fully closed The on-off valve according to claim 1 .   The on-off valve according to any one of claims 1 to 5, wherein a bonnet is provided on an upper portion of the body, and a stem is slidably sealed with a shaft seal packing attached to the bonnet. An exhaust apparatus for semiconductor manufacturing equipment, wherein the on-off valve according to any one of claims 1 to 6 is disposed at an appropriate position of an exhaust system for semiconductor manufacturing equipment .

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